Definitions and Standards in the Diagnosis and ... - Hematologics Inc.

Definitions and Standards in the Diagnosis and Treatment
of The Myelodysplastic Syndromes: Consensus Statements
and Report from a Working Conference
Peter Valent 1* , Hans-Peter Horny 2 , John M. Bennett 3 , Christa Fonatsch 4 ,
Ulrich Germing 5 , Peter Greenberg 6 , Torsten Haferlach 7 , Detlef Haase 8 , Hans-
Jochen Kolb 9 , Otto Krieger 10 , Michael Loken 11 , Arjan van de Loosdrecht 12 ,
Kiyoyuki Ogata 13 , Alberto Orfao 14 , Michael Pfeilstöcker 15 , Björn Rüter 16 ,
Wolfgang R. Sperr 1 , Reinhard Stauder 17 , Denise A. Wells 11
1 Department of Internal Medicine I, Division of Hematology & Hemostaseology, Medical University of Vienna,
Vienna, Austria
2 Klinikum Ansbach, Institute of Pathology, Ansbach, Germany
3 James P. Wilmot Cancer Center, University of Rochester Medical Center, Rochester, NY, USA
4 Institute of Human Genetics (KIMCL), Medical University of Vienna, Vienna, Austria
5 Department of Hematology Oncology and Clinical Immunology, Heinrich-Heine-University, Düsseldorf,
Germany
6 Stanford University Cancer Center, Stanford, CA, USA
7 MLL Munich Leukemia Laboratory, Munich, Germany
8 Department of Hematology and Oncology, Georg-August-University, Göttingen, Germany
9 Department of Medicine III, University of Munich, GSF-National Research Centre for Environment and Health,
Munich, Germany
10 First Department of Internal Medicine, Elisabethinen Hospital, Linz
11 Hematologics, Inc., Fred Hutchinson Cancer Research Center, Seattle, WA, USA
12 Department of Hematology, VU University Medical Center, Amsterdam, The Netherlands
13 Division of Hematology, Department of Medicine, Nippon Medical School, Tokyo, Japan
14 Servicio Central de Citometría, Centro de Investigación del Cáncer and Department of Medicine, Universidad
de Salamanca, Spain
15 Ludwig-Boltzmann Institute for Leukemia Research and Hematology, Vienna, Austria
16 Department of Hematology/Oncology, Albert-Ludwigs- University (ALU) Freiburg, Germany
17 Division of Hematology and Oncology, Innsbruck Medical University, Innsbruck, Austria
Key words: Myelodysplastic Syndromes • Criteria • Standardization • Patient Selection • ICUS
Contributions: All persons listed as co-authors contributed to pre-conference and post-conference
discussions (October 2005 until September 2006) and actively participated in the Standardization
Conference (Vienna, July 7-9, 2006). All co-authors contributed equally by discussing criteria,
standards, algorithms, and recommendations at the Working Conference. In addition, all persons listed
as co-authors provided essential input by drafting parts of the manuscript and by approving the final
version of the document.
*Correspondence to:
Peter Valent, M.D.
Department of Internal Medicine I,
Division of Hematology & Hemostaseology
Medical University of Vienna,
Waehringer Guertel 18-20, A-1090 Vienna, Austria
Tel:+431 404005488; Fax:+431 4026930
E-mail: peter.valent@meduniwien.ac.at
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Summary
The classification, scoring systems, and response criteria for myelodysplastic
syndromes (MDS) have recently been updated and have become widely accepted. In
addition, several new effective targeted drugs for patients with MDS have been
developed. The current article provides a summary of updated and newly proposed
markers, criteria, and standards in MDS, with special reference to the diagnostic
interface and refinements in evaluations and scoring. Concerning the diagnostic
interface, minimal diagnostic criteria for MDS are proposed, and for patients with
unexplained cytopenia who do not fulfil these criteria, the term ´idiopathic cytopenia
of uncertain significance´ (ICUS) is suggested. In addition, new diagnostic and
prognostic parameters, histopathologic and immunologic determinants, proposed
refinements in scoring systems, and new therapeutic approaches are discussed.
Respective algorithms and recommendations should facilitate diagnostic and
prognostic evaluations in MDS, selection of patients for therapies, and the conduct of
clinical trials.
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Introduction
Myelodysplastic syndromes (MDS) represent a heterogeneous group of myeloid
neoplasms characterized by abnormal differentiation and maturation of myeloid cells,
bone marrow (bm) failure, and a genetic instability with enhanced risk to transform to
acute myeloid leukemia (AML). MDS are classified according to their etiology
(primary = de novo; or following a known mutagenic event = secondary), cytologic
features of bm and blood cells, and specific karyotypes.
A most useful classification system, that has been applied successfully, was the
proposal of the French-American-British (FAB) cooperative study group [1]. This
proposal is primarily based on morphologic criteria. More recently, the World Health
Organization (WHO) has worked out an updated classification that represents an
extension of the FAB proposal, with several modifications, which include the removal
of RAEB-T (now considered to belong to the AML section) and of chronic
myelomonocytic leukemia (now in MDS/MPD-interface group), recognition of the
impact of multilineage dysplasia in RA and RARS, and delineation of a
cytogenetically defined subvariant, the 5q- syndrome [2,3].
However, in any particular WHO category, the prognosis and clinical course vary
among patients. Whereas some transform to leukemia or die from complications of bm
failure within a short time, other MDS patients survive for many years without major
clinical problems. Therefore, during the past few decades, a number of attempts have
been made to establish scoring systems that can more accurately predict the prognosis
concerning survival and evolution to AML [3-5]. These systems were based on
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multiple prognostic parameters such as the percentage of blasts, karyotype, and
number of cytopenias. In 1997, the ´International Prognostic Scoring System´ (IPSS)
has been introduced [4]. This score system has become the gold standard for risk
assessment in patients with de novo MDS, and is widely used for stratification in
clinical trials as well as for patient-selection in clinical practice.
However, despite the availability of the WHO classification and the IPSS, there
remains a need to further improve diagnostic and prognostic scores and to define
standards for evaluations, patient selection, and for the use of targeted drugs in the
various subgroups of MDS. This is important because of the complexity of the disease
and the increasing number of emerging targets and therapeutic approaches. In addition,
many concepts and algorithms are based on FAB variants, and may not count in the
same way when patients are evaluated using the WHO or IPSS score.
To address these issues, a number of efforts and projects are currently in progress –
many of them conducted in well-recognized expert panels, such as the US National
Comprehensive Cancer Network (NCCN), the International Working Group (IWG), or
the European Leukemia Net (ELN). We report on a Working Conference on MDS,
convened in the Year 2006, which included representatives from these groups. In this
workshop, current criteria and standards in MDS were discussed and are presented as a
consensus herein. In addition, potential forthcoming standards were discussed.
Definition of MDS and Minimal Diagnostic Criteria
MDS are defined as a group of myeloid neoplasms characterized by bm failure with
peripheral cytopenia and morphologic dysplasia in one or more of the following
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hematopoietic cell lineages: i. erythroid cells (also ringed sideroblasts >15%
considered diagnostic), ii. neutrophils and their precursors, and iii. megakaryocytes.
Respective criteria were originally established by the FAB study group [1] and later
were adopted with modifications by the WHO [2].
In most patients, it is thus straightforward to diagnose MDS on the basis of WHO
criteria. However, in many cases with cytopenia(s), it may be quite difficult to
establish (or exclude) the diagnosis MDS. These may be patients without a cytogenetic
abnormality and only mild cytopenia, patients with a typical karyotype and cytopenia
but only slight or absent dysplasia, or patients with transfusion-dependent macrocytic
anemia without karyotype abnormalities and without diagnostic dysplasia.
To assist in these situations, minimal diagnostic criteria sufficient to call a condition
MDS, were discussed and presented as a consensus-proposal. This proposal is based
on two ´prerequisite-type criteria´ (both must be fulfilled), at least one (out of 3)
additional MDS-related (decisive) criterion, and several co-criteria (Table 1).
Diagnostic prerequisites are a) marked and constant cytopenia (≥6 months unless
cytogenetic studies reveal MDS) in at least one of the following hematopoietic cell
lineages: erythroid cells (

eported to occur in MDS), iii. a constant blast cell count of 5-19%. In patients with
´subdiagnostic´ or questionable results in i.-iii. (e.g. atypical chromosome aberration,
dysplasia in

MDS or an MDS-prephase. These patients should then be carefully monitored and
repeated tests be performed in the follow up to confirm or exclude MDS. If suspicion
for MDS becomes evident from the routine follow up, a repeat bm examination should
be performed.
At initial presentation, it is standard to perform a sufficient hematologic investigation
in all patients, including a bm trephine biopsy with appropriate histology and
immunohistochemistry, bm smear-examinations with Romanowsky stain and iron
stain as well as cytogenetics (Table 2).
The bone marrow and peripheral blood smear
The examination of an appropriately prepared and stained bm and peripheral blood
smear remains the most important diagnostic approach in patients with (suspected)
MDS [1-3]. For proper morphologic assessment, well prepared thin films (bm films
containing particles at the feathered edge) are required. An excellent Romanowsky
stain (MGG or WG stain) should be utilized that has a good balance between the the
azur dyes to identify the cytoplasmic granules and basophilic cytoplasm. Overstaining
on thick smears results in all cells resembling each other, and understaining prevents
the separation of the major cell lines as well (and may mimic hypogranulated
neutrophils). An iron stain of the aspirate (Perl’s reagent) with a nuclear counterstain
should be performed in all cases to identify sideroblasts. For an accurate differential
count, at least 500 nucleated cells should be counted in the bm smear. In each case, the
cellularity of the smear, erythroid-to-myeloid (E:M) ratio, and the percentage of blasts
should be reported. In cases where the E:M ratio is 1:1 or greater, one should count
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500 nonerythroid cells, eliminating lymphocytes, plasma cells, and mast cells. Also,
when the E:M ratio is 1:1 or greater, the percentage of blasts is based on the non-
erythroid component.
If more than 10% of cells in the erythroid, neutrophil granulocytic, or megakaryocytic
lineage in the bm smear show dysplasia, the diagnosis MDS can be established
provided that cytopenia is present and other diseases have been excluded as sole
reason for dysplasia/cytopenia (note, however, that a co-existing myelogenous disease
per se does not exclude MDS!). The demonstration of >15% ringed sideroblasts is also
considered a diagnostic sign of erythroid dysplasia [1]. The diagnosis MDS can be
established in such cases even if morphologic dysplasia is found in less than 10% of
cells.
A number of morphologic criteria for the various cells recorded in MDS are available.
Myeloblasts can be divided into non-granulated blast cells and blast cells with
granules. In routine diagnostics, it is not required to report on the various subtypes of
blast cells.
Apart from the bm, it is also important to review the peripheral blood smear in all
cases with MDS and to report morphologic features of myeloid cells (Pseudo-Pelger-
Huet forms, hypogranulated neutrophils, others) and the differential count in all cases.
Bone Marrow Histology and Immunohistochemistry in MDS: Standards
and Recommendations
A histologic examination of the bm is recommended in all patients with suspected
MDS [6-9]. In those in whom ICUS is diagnosed, the bm histology is essential to
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exclude an underlying ´occult´ myelogenous neoplasm (e.g. mastocytosis, lymphoma,
others) or other non-hematopoietic disorders (e.g. gelatinous transformation of the
bone marrow; certain infectious diseases such as leishmaniosis; metastasis).
In patients with established MDS, the bm histology may yield important diagnostic
information and features, such as bm fibrosis, small clusters of immature (CD34+)
progenitor cells, increased angiogenesis, or a hypocellular marrow (Table 3A) [6-12].
The IHC-based determination of the percentage of CD34+ progenitor cells in the bm is
important when the bm smear is contaminated with peripheral blood cells.
For diagnostic evaluation, the bm biopsy specimen is usually obtained from the
posterior iliac spine and should be of adequate length (≥1.5 cm). The specimen should
be fixed in neutral formalin, decalcified in editic acid for at least 8 hours, and
embedded in paraffin-wax. Recommended standard routine stains include H&E,
Giemsa, Prussian blue, naphtol AS-D chloroacetate esterase (CAE), and Gömöri´s
silver impregnation. CAE is of superior value for detection of even minor alterations
of the microarchitecture of the bm including minute infiltrates of CAE-negative cells
(e.g. blasts).
The bm cellularity should be determined as percentage of bm section-area according to
the standard proposed by Tuzuner and Bennett with recognition of age-dependent
differences in cellularity [13,14]. It is therefore recommended that the pathologist
determines the cellularity as ´normocellular´, ´hypocellular´, or ´hypercellular´, based
on an age-adapted estimate.
The application of immunohistochemical (IHC) markers is recommended in all
patients with (suspected) MDS. The minimal panel recommended includes CD34
(progenitor cells), a megakaryocyte marker (CD31, CD42, or CD61), and tryptase
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(mast cell-related antigen). In difficult cases, additional lineage-specific antibodies
such as CD3, CD20, CD25, CD117, or others, should be employed depending on the
differential diagnosis (Table 3B).
When employing CD34 as a progenitor-related IHC marker in MDS [8-10], the
additional labelling of larger and smaller blood vessels has to be taken into account,
which enables reporting on angiogenesis. If the microvessel density is high, it may
then be difficult to differentiate blast cells from endothelium, i.e. to give an exact
estimate on the percentage of CD34+ progenitor cells. Another limitation of CD34 is
that in a few patients with MDS, progenitor cells may be CD34-negative. In such
cases, CD117 can be applied as an alternative (Table 3B). Nevertheless, in most cases,
it is a straightforward approach to count progenitor cells (blasts) using antibodies
against CD34 [8-10]. Thus, such antibodies can be used for detection of even a slight
diffuse increase in blast cells, and for assessment of small compact blast cell infiltrates
that may escape cytological investigation in bm smears. The estimated percentage of
CD34+ progenitors, known to be of prognostic significance, should be reported in each
case. This is also of importance when investigations of bm aspirates did not show
conclusive results.
A number of previous studies have reported on the diagnostic and prognostic value of
an ´atypical localization of immature progenitor cells´ (ALIP) in MDS [7]. These
studies have recently been confirmed using antibodies against CD34. Thus, antibodies
against CD34 can assist in reporting on ALIP. However, the term ALIP may not be
optimal because contrasting the initial definition of ALIP (no vicinity to vessels or
endosteal surfaces), the vicinity of a vessel or endosteal surface can usually not be
10

excluded. Therefore, we recommend to avoid the term ´ALIP´, and to replace it by
describing ´multifocal accumulations of CD34+ progenitor cells´ in pathology reports.
Megakaryocyte markers (e.g. CD31, CD42, or CD62) enable the detection of an
atypical accumulation (grouping or clustering) and cytomorphological atypia of
megakaryocytes. In fact, in almost all patients with MDS, megakaryocytes show cell
atypia and abnormal distribution [6]. In contrast to other bm cells, it is possible to
assess cytological atypia of megakaryocytes in adequately processed bm sections.
Tryptase IHC is useful to detect loosely scattered mast cells which are increased in
almost all cases of MDS and may show spindle-shape appearance [15,16]. Serum
tryptase levels are also elevated in a group of patients with MDS [17]. If mast cells
form compact clusters in the bm and/or express CD25, or tryptase levels are very high,
it is appropriate to perform mutation analysis of KIT. In such cases, a coexisting
mastocytosis (occult mastocytosis) may be detected [15,16].
Karyotyping in MDS: Current Standards and Recommended Procedures
Conventional karyotyping employing different chromosome-banding techniques (G-,
Q-, and R-banding) remains an integral component and standard in the diagnostic
work up of patients with (suspected) MDS [18-20]. By consensus, at least 20-25 bm
metaphases should be examined. In certain instances (clear-cut demonstration of
clonal aberrations), 20 or even 10 metaphases may be sufficient.
Karyotypes should be reported according to ISCN guidelines [21]. Based on these
guidelines, a clone is defined by two bm cells showing the same gain of chromosomal
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material or the same structural aberration, or by at least three bm cells showing loss of
the same chromosome [21].
In questionable cases (e.g. low number of metaphases in conventional karyotyping; or
ICUS versus low risk MDS), additional fluorescence in situ hybridization (FISH) is
recommended as a second step and should then count in the demonstration of a clone
[22-24] with the same diagnostic criteria that are used for conventional karyotyping.
Such FISH investigations should include probes covering (at least) the following
regions: 5q31, CEP7, 7q31, CEP8, 20q, CEPY, and p53. Clonality by FISH is proven
on the basis of the diagnostic cut off defined by the sensitivity of the probe. In case of
small percentages (5-10%) of ´FISH-positive´ cells, a repeat analysis of the bm should
be recommended. If available, multicolor FISH (mFISH; 24-color FISH, SKY) can be
performed to better characterize marker chromosomes and complex aberrations [24].
However, mFISH must be performed on metaphases after culturing bm cells, whereas
interphase FISH can also be performed on bm smears. In select cases, i.e. if no bm
material is available, peripheral blood cells may be examined. Note, however, that if a
negative result is obtained from the blood, this does not exclude the presence of
karyotype abnormalities in bone marrow cells.
In a group of patients, clonal evolution with development of one or more subclones is
reported. A subclone is defined by the presence (occurrence) of additional (so called
secondary) chromosome aberrations in at least 2 or 3 cells (of the entire clone)
according to the definition of clonality (see above). The occurrence of a population of
bm cells with independent chromosomal abnormalities is rarely seen. In these cases it
is usually impossible to define whether these cells represent a subclone (of an original
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neoplastic stem cell clone that did not exhibit any of the later acquired chromosomal
abnormalities) or represent a new clone.
A complex aberrant karyotype is defined by at least three independent chromosome
aberrations in at least two cells [18-21]. The complex karyotype may also include
subclones or even independent clones which by themselves may show a complex
chromosome pattern (three or more abnormalities). In this regard it is also noteworthy
that the ´complex karyotype group´ of MDS patients may consist of several subgroups
reflecting different ´degrees of complexity´, and thus a variable prognosis.
During the follow up of patients with MDS, karyotyping should be considered in case
of suspected progression. In certain instances (e.g. when it is important to recognized
progression as soon as possible) it may be preferable to perform karyotyping every 6-
12 months. A comparison with the original karyotype may reveal cytogenetic evidence
of clonal evolution. Although the exact prognostic impact of each of the acquired
chromosomal defect in MDS remains unknown, it is generally appreciated that
karyotype evolution is associated with disease progression.
Moreover, karyotyping at diagnosis is a most important prognostic approach and
therefore has been included in several prognostic scoring systems including the IPSS.
The use of new effective drugs has recently led to an updated formulation of response
criteria in MDS, including a ´complete cytogenetic response´ that may e.g. be seen in
5q- patients treated with lenalidomide or those who receive intensive chemotherapy.
Molecular Typing and Point Mutation Analysis in MDS
13

In recent years, gene expression profiling (GEP) based on microarray analysis has
been introduced as a powerful new tool in leukemia research. However, little is known
so far about the potential value of gene chip profiling in MDS. First data suggest that
microarray-based GEP (performed with CD34+ or CD133+ cells) can define specific
and prognostically relevant gene signatures that may correlate with FAB-, WHO-, or
IPSS subtypes [25,26]. However, there may be a considerable overlap in gene
expression profiles, when high risk MDS are compared with secondary AML, or low
risk MDS with control samples (normal bm). Nevertheless, in a group of patients,
microarray analysis may help in reaching the conclusion the patient is suffering from a
clonal myeloid disorder. In patients with otherwise typical clinical features (e.g.
transfusion-dependent macrocytic anemia), such ´monoclonal´ pattern together with
other co-criteria may lead to the conclusion the condition is ´highly suspective of
MDS´. In addition, GEP may help to predict responses to therapies in MDS in the
future. All in all, GEP is an exciting new tool and may become a future diagnostic
approach in MDS, but further studies are required to define the exact diagnostic and
prognostic impact of GEP.
In certain clinical situations, mutation analysis seems useful as a diagnostic approach
in MDS. Examples for such investigations are suspected associated systemic
mastocytosis (screen for KIT mutation D816V) [15,16] or MDS with marked
thrombocytosis, where molecular analysis may reveal the V617F Jak-2 mutation
[27,28]. This mutation has been described to occur in a few patients with MDS
including a small subgroup of 5q- patients [28]. In other cases, the detection of Jak-2
V617F (together with other features) may lead to the conclusion the patient is
suffering from an overlap syndrome (MDS/MPD).
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Flow Cytometry in MDS
A number of recent data suggest that flow cytometry can assist in the diagnosis and
prognostication in MDS [29-32]. In the diagnostic work up in suspected MDS, flow
cytometry is of value in the quantitative and qualitative assessment of CD34+
progenitor cells (blasts), maturing myeloid cells, and monocytes. Results from
quantitative assessments may be of particular value when bm smears are of suboptimal
quality or missing, or monocytic cells are extremely immature (CMML versus AML).
Qualitative features may help in reaching the conclusion the patient is suffering from a
clonal myeloid disorder [29-32]. In fact, although no marker-abnormality and no
abnormal marker profile is specific for MDS, such changes may help in discriminating
a normal/reactive bm from a clonal myeloid malignancy (e.g. ICUS versus low risk
MDS/RA). Whereas a single phenotypic abnormality should not be regarded as
indicative, the likelihood of a myeloid neoplasm increases with the number of
phenotypic deviations. However, the final diagnosis of MDS has to be based on
additional (clinical and laboratory) features/criteria. A summary of repeatedly
described phenotypic abnormalities in the various myeloid lineages in MDS is
depicted in Table 4.
Apart from the value of flow cytometry as a diagnostic tool, phenotyping may also
assist in prognostication in MDS [30-32]. In particular, a number of recent studies
have shown that phenotypic abnormalities in MDS correlate with prognosis. In
addition, a flow cytometry may improve currently available prognostic scoring
systems [30]. Larger prospective multicenter studies are required, however, to define
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the precise value of flow cytometry as a generally applicable standard of
prognostication in MDS. Thus, a current disadvantage of flow cytometry in MDS is
that no generally accepted consensus on uniformely used standard protocols and
techniques is available. Therefore, the most important aim for the future is to develop
multi-center projects with the aim to standardize and harmonize methodologies and
reagents, in order to increase the general impact and awareness of this important
approach, and to facilitate its use as a general standard in clinical practice and trials.
Risk Scoring Systems in MDS: Proposed Refinement of the IPSS and
Forthcoming Scores
A number of risk factors concerning survival and AML-development have been
identified in the past [1-5]. For some of these factors, like age, the prognostic impact
on survival may be quite different from the impact on AML development. Still,
however, all score approaches in use represent unidirectional systems without
evaluating these two end points separately. In 1997, the international prognostic
scoring system (IPSS) was introduced [4]. This scoring system represents the gold
standard in prognostication in MDS. However, despite the generally accepted value of
the IPSS, additional refinements have been proposed. Here, one important aspect is
that additional well-established prognostic variables, such as the lactate dehydrogenase
(LDH), have not been included in the IPSS. Interestingly, an elevated LDH splits each
IPSS-category into two prognostically different subgroups [33,34].
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So far, it also remains unknown whether the IPSS scoring system can be applied to all
groups of patients diagnosed according to the WHO classification in the same way as
it has been described for patients diagnosed according to FAB criteria.
A potential new forthcoming scoring system may be the recently proposed WHO-
adjusted (WPSS) scoring system that includes transfusion dependence as an important
variable. However, all these propsed refinements and new scores have to be validated
against the IPSS in forthcoming studies before they can be generally accepted as
standard.
Non-Intensive Therapy in MDS, Predictive Scores, and Response Criteria
In patients with low risk MDS who are not considered for intensive therapy, the most
important goal is to maintain quality of life (QOL) [35-38] and to prevent transfusion-
related morbidity and mortality, mostly resulting from iron overload, which may
become apparent when the number of RBC transfusions exceeds 20-40 and serum
ferritin levels exceed 1500-2000 ng/ml. In patients with high risk MDS who are not
considered for intensive therapy, major goals are to counteract disease progression
using palliative, targeted, or experimental drugs and to manage the consequences of
thrombocytopenia and neutropenia [35-38]. Again, maintenance of QOL is a most
important goal in these patients [35-38].
Erythropoietin (EPO) with or without additional G-CSF is considered standard for
treatment of low risk or INT-1 patients with transfusion-dependent anemia in whom
endogenous EPO levels and the frequency of transfusions are low [39-42]. Respective
criteria for patient selection are available [39-41]. Recently, long-acting EPO
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(darbepoetin-alpha) has been introduced in the therapy of MDS with encouraging first
results [42].
In chronically transfused MDS patients, the direct approach to counteract iron
overload is continuous treatment with iron-chelating agents such as desferoxamine,
deferiprone (L1), or deferasirox (ICL670), the latter two drugs being administered
orally [43].
In patients with recurrent or refractory neutropenic infections, therapy with G-CSF is
usually recommended. GM-CSF may be considered as alternative. In special situations
(high risk for recurrent infections), G-CSF or GM-CSF may also be considered as
prophylactic drug(s). In addition, as mentioned above, G-CSF is administered together
with EPO in low/intermediate risk patients to augment the erythroid response, which
may be particularly effective in those suffering from RARS. Otherwise, CSFs are not
used routinely in MDS. Recently, thrombopoietic cytokines such as TPO or IL-11
have been introduced in clinical trials in MDS patients with variable effects. However,
these cytokines are not considered standard of therapy in MDS.
Treatment response criteria defining hematologic improvement in one or more
myeloid lineages (erythroid response, neutrophil response, platelet response) are
available and should be applied as standard [44,45]. The initially proposed response
criteria have recently been updated and modified with important simplifications [45].
In low risk patients, response evaluation for iron overload may be of importance.
Finally, the changes (improvement) in quality of life (QOL) during non-intensive
therapy is considered a most important parameter to be evaluated in patients with (low
risk) MDS [38]. Notably, for most patients with MDS, the most important effect of
therapy is improvement of QOL. Therefore, it is recommended to evaluate QOL
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efore and during therapy using appropriate questionnaires and to include QOL scores
and response evaluations in clinical practice as well as in investigational trials.
Intensive Therapy in MDS: Current Standards
One of the most important question to be addressed in patients with MDS is whether a
curative treatment approach should be considered. When planning intensive therapy,
several important aspects have to be considered:
1. For most patients with MDS, the only curative treatment approach is hematopoietic
stem cell transplantation (SCT). However, this therapy can only be offered to a small
number of patients and is associated with a relatively high risk of transplant-related
morbidity and mortality.
2. Intensive polychemotherapy can restore normal polyclonal hematopoiesis in a
subset of patients, but can induce long term disease-free survival in only a few
patients, whereas most of them will relapse after a variable time period.
3. The natural course of MDS is variable, with survival times ranging from a few
months to several years even in those who have high risk MDS.
4. Comorbidity, age, and other individual factors may influence the outcome of SCT
(and of intensive chemotherapy) in patients with MDS. In patients with advanced
MDS (IPSS HIGH; >5% blasts), the probability of post-transplant relapse ranges
between 10% and 40% [46].
Thus, many different factors may count, and the final decision must always be based
on multiple parameters and the individual situation in each case.
A number of different chemotherapy protocols have been proposed for the treatment of
patients with high risk MDS. Most of these protocols are similar compared to those
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applied to patients with AML [46,47]. Using such protocols, a subgroup of patients
with MDS (roughly 50%) enter complete hematologic remission (CR). In (young)
patients who have achieved CR and have a suitable donor, SCT should then be
considered as appropriate consolidation.
The optimal timing of SCT (+/- preceding chemotherapy) in patients with MDS is
unknown. Recent data suggest that for LOW and INT-1 patients, overall survival can
be maximized when SCT is delayed, whereas for INT-2 and HIGH patients, early SCT
is associated with improved survival [48]. In select patients with low risk MDS, the 3-
year survival amounts to approximately 70% using HLA-matched related or unrelated
donors [46]. In unselected, high risk, and comorbid patients, the outcome is clearly
worse [48,49]. In many cases, a reasonable approach may be to start with
polychemotherapy in order to reduce the disease-burden and to explore the
responsiveness of the clone and the possibility to introduce intensive therapy in the
individual patient (tolerability against intensive therapy). In addition, comorbidity
scores are available that may help to select patients who can benefit from SCT.
Regarding age, recent data suggest that in selected patients over 60 years of age (even
up to 70 years), SCT may be performed as a relatively safe approach [46,48-50].
Another important issue is optimal conditioning. Here, both conventional and reduced-
intensity/non-myeloablative regimens have been used successfully [48,49]. Reduced-
intensity conditioning is associated with a decrease in non-relapse mortality and may
allow for SCT in older patients [46].
Another interesting (albeit experimental) approach is autologous SCT. This therapy is
an option for patients who are young and have entered CR after induction
chemotherapy, but do not have a suitable transplant donor.
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Once disease-relapse has occurred in a patient with MDS after SCT, treatment options
are limited. In some patients, re-induction followed by donor lymphocyte infusion may
be considered [50]. However, if at all seen, remissions usually are short lived.
Immunosuppressive Drugs, New Targeted Drugs, and Palliative Therapy
A number of new drugs and therapeutic concepts have been introduced in MDS in the
past few decades. These include low dose chemotherapy, immunosuppressive therapy,
demethylating agents, anti-apoptotic strategies, targeted drugs, anti-cytokine therapy,
and differentiation-inducing therapy [51-59]. However, of the many drugs tested, only
a few are considered potential standard in MDS. These drugs include 5-azacytidine (5-
Aza), 5-aza-2-deoxycytidine (decitabine), lenalidomide (revlimid), anti-thymocyte
globulin (ATG), and cyclosporin A (CSA). Most of these drugs has been shown to
produce major responses in MDS in a subgroup of patients. Likewise, lenalidomide
has been described to produce major clinical and even cytogenetic responses in a
group of patients with the 5q- abnormality [59]. Therefore, today, in 5q- patients with
symptomatic anemia, lenalidomide is considered first line therapy after a trial of
erythropoietin. ATG±CSA may work in a subgroup of (younger) patients with low risk
MDS (RA; IPSS INT-1 group) [57,58]. Those presenting with HLADR15, a PNH
subclone, or hypoplastic MDS, may have a better chance to respond [57,58].
Decitabine and 5-azacytidine have shown encouraging results in a group of MDS
patients, often with major and long lasting responses [52-56]. In low risk patients,
these drugs are only considered when signs of progression occur. In several centers,
demethylating agents are already considered as forthcoming standard of therapy in
21

high risk MDS, although these drugs did not yet receive regular approval in all
countries. An important aspect is that responses to demethylating agents are often seen
only after a latency period of several months. Therefore, at least three cycles of
decitabine or 5-azacytidine should be administered in each case, and thereafter the
response be evaluated as basis for the decision to continue therapy. In all patients and
with all drugs applied, treatment responses should be measured using available
response-criteria and respective guidelines.
Apart from the above mentioned drugs, general supportive therapy is essential to help
maintaining QOL in patients with MDS. Palliative cytoreduction (for patients with
leukocytosis) is usually performed using hydroxyurea. In such cases, the use of
experimental drugs and the conduct of clinical trials has to balanced against the overall
clinical situation of the patient, age, and QOL.
Concluding Remarks and Future Perspectives
The increasing numbers of tests, markers, targets, and therapeutic options in MDS is a
challenge for the physician. Based on such developments, it is important to revisit and
refine criteria and standards. The current article reports the outcomes of a Working
Conference in which these issues were discussed, with special focus on the diagnostic
interface, minimal diagnostic criteria, potential refinements in current scoring systems,
and emerging new diagnostic and therapeutic approaches. It is the hope for the future
that these concepts will result in the formulation of updated recommendations and
guidelines, and thus improvement of diagnosis and treatment in patients with MDS.
22

References
1. Bennett JM, Catovsky D, Daniel MT, Flandrin G, Galton DA, Gralnick HR, Sultan
C. Proposals for the classification of the myelodysplastic syndromes. Br J Haematol
1982;51:189-99.
2. Brunning RD, Bennett JM, Flandrin G, Matutes E, Head D, Vardiman JW, Harris
NL. Myelodysplastic Syndromes. in: World Health Organization Classification of
Tumours. Pathology & Genetics. Tumours of Haematopoietic and Lymphoid Tissues.
Jaffe ES, Harris NL, Stein H, Vardiman JW (eds). IARC Press Lyon, 2001; vol 1. pp
62-73.
3. Bennett JM. A comparative review of classification systems in myelodysplastic
syndromes (MDS). Semin Oncol 2005;32:S3-S10.
4. Greenberg P, Cox C, LeBeau MM, Fenaux P, Morel P, Sanz G, et al. International
scoring system for evaluating prognosis in myelodysplastic syndromes. Blood
1997;89:2079-88.
5. Bennett JM, Komrokji RS. The myelodysplastic syndromes: Diagnosis, molecular
biology and risk assessment. Hematology 2005;10:258-69.
23

6. Thiele J, Quitmann H, Wagner S, Fischer R. Dysmegakaryopoiesis in
myelodysplastic syndromes (MDS): an immunomorphometric study of bone marrow
trephine biopsy specimens. J Clin Pathol 1991;44:300-5.
7. Tricot G, De Wolf-Peeters C, Vlietinck R, Verwilghen RL. Bone marrow histology
in myelodysplastic syndromes. II. Prognostic value of abnormal localization of
immature precursors in MDS. Br J Haematol 1984;58:217-25.
8. Horny HP, Wehrmann M, Schlicker HU, Eichstaedt A, Clemens MR, Kaiserling E.
QBEND10 for the diagnosis of myelodysplastic syndromes in routinely processed
bone marrow biopsy specimens. J Clin Pathol 1995;48:291-4.
9. Oriani A, Annaloro C, Soligo D, Pozzoli E, Cortelezzi A, Lambertenghi Deliliers G.
Bone marrow histology and CD34 immunostaining in the prognostic evaluation of
primary myelodysplastic syndromes. Br J Haematol 1996;92:360-4.
10. Baur AS, Meuge-Moraw C, Schmidt PM, Parlier V, Jotterand M, Delacretaz F.
CD34/QBEND10 immunostaining in bone marrow biopsies: an additional parameter
for the diagnosis and classification of myelodysplastic syndromes. Eur J Haematol
2000;64:71-9.
11. Verburgh E, Achten R, Maes B, Hagemeijer A, Boogaerts M, De Wolf-Peeters C,
24

Verhoef G. Additional prognostic value of bone marrow histology in patients
subclassified according to the International Prognostic Scoring System for
myelodysplastic syndromes. J Clin Oncol 2003;21:273-82.
12. Lambertenghi-Deliliers G, Annaloro C, Oriani A, Soligo D. Myelodysplastic
syndrome associated with bone marrow fibrosis. Leuk Lymphoma 1992;8:51-5.
13. Tuzuner N, Bennett JM. Reference standards for bone marrow cellularity. Leuk
Res 1994;18:645-7.
14. Tuzuner N, Cox C, Rowe JM, Bennett JM. Bone marrow cellularity in myeloid
stem cell disorders: impact of age correction. Leuk Res 1994;18:559-64.
15. Horny HP, Greschniok A, Jordan JH, Menke DM, Valent P. Chymase expressing
bone marrow mast cells in mastocytosis and myelodysplastic syndromes: an
immunohistochemical and morphometric study. J Clin Pathol 2003;56:103-6.
16. Horny HP, Sotlar K, Sperr WR, Valent P. Systemic mastocytosis with associated
clonal haematological non-mast cell lineage diseases: a histopathological challenge. J
Clin Pathol 2004;57:604-8.
17. Sperr WR, Stehberger B, Wimazal F, Baghestanian M, Schwartz LB, Kundi M,
Semper H, Jordan JH, Chott A, Drach J, Jager U, Geissler K, Greschniok A, Horny
25

HP, Lechner K, Valent P. Serum tryptase measurements in patients with
myelodysplastic syndromes. Leuk Lymphoma 2002;43:1097-105.
18. Fenaux P. Chromosome and molecular abnormalities in myelodysplastic
syndromes. Int J Hematol 2001;73:429-37.
19. Steidl C, Steffens R, Gassmann W, Hildebrandt B, Hilgers R, Germing U, Trumper
L, Haase D. Adequate cytogenetic examination in myelodysplastic syndromes:
analysis of 529 patients. Leuk Res 2005;29:987-93.
20. Haase D, Fonatsch C, Freund M, Wormann B, Bodenstein H, Bartels H,
Stollmann-Gibbels B, Lengfelder E. Cytogenetic findings in 179 patients with
myelodysplastic syndromes. Ann Hematol 1995;70:171-87.
21. ISCN. An international system for human cytogenetic nomenclature. Cytogenet
Cell Genet 1981;31:5.
22. Cherry AM, Brockman SR, Paternoster SF, Hicks GA, Neuberg D, Higgins RR,
Bennett JM, Greenberg PL, Miller K, Tallman MS, Rowe J, Dewald GW. Comparison
of interphase FISH and metaphase cytogenetics to study myelodysplastic syndrome: an
Eastern Cooperative Oncology Group (ECOG) study. Leuk Res 2003;27:1085-90.
23. Bernasconi P, Cavigliano PM, Boni M, Calatroni S, Klersy C, Giardini I, Rocca B,
Crosetto N, Caresana M, Lazzarino M, Bernasconi C. Is FISH a relevant prognostic
26

tool in myelodysplastic syndromes with a normal chromosome pattern on conventional
cytogenetics? A study on 57 patients. Leukemia 2003;17:2107-12.
24. Babicka L, Ransdorfova S, Brezinova J, Zemanova Z, Sindelarova L, Siskova M,
Maaloufova J, Cermak J, Michalova K. Analysis of complex chromosomal
rearrangements in adult patients with MDS and AML by multicolor FISH. Leuk Res,
2006, in press.
25. Hofmann WK, de Vos S, Komor M, Hoelzer D, Wachsman W, Koeffler HP.
Characterization of gene expression of CD34+ cells from normal and myelodysplastic
bone marrow. Blood 2002;100:3553-60.
26. Pellagatti A, Esoof N, Watkins F, Langford CF, Vetrie D, Campbell LJ, Fidler C,
Cavenagh JD, Eagleton H, Gordon P, Woodcock B, Pushkaran B, Kwan M, Wainscoat
JS, Boultwood J. Gene expression profiling in the myelodysplastic syndromes using
cDNA microarray technology. Br J Haematol 2004;125:576-83.
27. Szpurka H, Tiu R, Murugesan G, Aboudola S, Hsi ED, Theil KS, Sekeres MA,
Maciejewski JP. Refractory anemia with ringed sideroblasts associated with marked
thrombocytosis (RARS-T), another myeloproliferative condition characterized by
JAK2 V617F mutation. Blood 2006;108:2173-81.
28. Ingram W, Lea NC, Cervera J, Germing U, Fenaux P, Cassinat B, Kiladjian JJ,
Varkonyi J, Antunovic P, Westwood NB, Arno MJ, Mohamedali A, Gaken J, Kontou
27

T, Czepulkowski BH, Twine NA, Tamaska J, Csomer J, Benedek S, Gattermann N,
Zipperer E, Giagounidis A, Garcia-Casado Z, Sanz G, Mufti GJ. The JAK2 V617F
mutation identifies a subgroup of MDS patients with isolated deletion 5q and a
proliferative bone marrow. Leukemia 2006;20:1319-21.
29. Ogata K, Nakamura K, Yokose N, Tamura H, Tachibana M, Taniguchi O, Iwakiri
R, Hayashi T, Sakamaki H, Murai Y, Tohyama K, Tomoyasu S, Nonaka Y, Mori M,
Dan K, Yoshida Y. Clinical significance of phenotypic features of blasts in patients
with myelodysplastic syndrome. Blood 2002;100:3887-96.
30. Wells DA, Benesch M, Loken MR, Vallejo C, Myerson D, Leisenring WM, Deeg
HJ. Myeloid and monocytic dyspoiesis as determined by flow cytometric scoring in
myelodysplastic syndrome correlates with the IPSS and with outcome after
hematopoietic stem cell transplantation. Blood 2003;102:394-403.
31. Benesch M, Deeg HJ, Wells D, Loken M. Flow cytometry for diagnosis and
assessment of prognosis in patients with myelodysplastic syndromes. Hematology
2004;9:171-7.
32. Ogata K, Kishikawa Y, Satoh C, Tamura H, Dan K, Hayashi A. Diagnostic
application of flow cytometric characteristics of CD34+ cells in low-grade
myelodysplastic syndromes. Blood 2006;108:1037-44.
28

33. Wimazal F, Sperr WR, Kundi M, Meidlinger P, Fonatsch C, Jordan JH, et al.
Prognostic value of lactate dehydrogenase activity in myelodysplastic syndromes.
Leuk Res 2001;25:287-94.
34. Germing U, Hildebrandt B, Pfeilstocker M, Nösslinger T, Valent P, Fonatsch C,
Lubbert M, Haase D, Steidl C, Krieger O, Stauder R, Giagounidis AA, Strupp C,
Kundgen A, Mueller T, Haas R, Gattermann N, Aul C. Refinement of the international
prognostic scoring system (IPSS) by including LDH as an additional prognostic
variable to improve risk assessment in patients with primary myelodysplastic
syndromes (MDS). Leukemia 2005;19:2223-31.
35. Valent P, Wimazal F, Schwarzinger I, Sperr WR, Geissler K. Pathogenesis,
classification, and treatment of myelodysplastic syndromes (MDS). Wien Klin
Wochenschr 2003;115:515-36.
36. Steensma DP, Bennett JM. The myelodysplastic syndromes: diagnosis and
treatment. Mayo Clin Proc 2006;81:104-30.
37. Malcovati L, Porta MG, Pascutto C et al . Prognostic factors and life expectancy in
myelodysplastic syndromes classified according to WHO criteria: a basis for clinical
decision making. J Clin Oncol 2005; 23:7594-7603.
38. Thomas ML. Health-Relaed Quality of Life for those with myelodysplastic
syndrome: Conceptualization, measurement and implications. In: Greenberg PL,
29

Editor, Myelodysplastic Syndromes: Clinical and Biological Advances. Cambridge
University Press, Cambridge, England; 2006: pp: 263-295.
39. Hellstrom-Lindberg E, Ahlgren T, Beguin Y, Carlsson M, Carneskog J, Dahl IM,
Dybedal I, Grimfors G, Kanter-Lewensohn L, Linder O, Luthman M, Lofvenberg E,
Nilsson-Ehle H, Samuelsson J, Tangen JM, Winqvist I, Oberg G, Osterborg A, Ost A.
Treatment of anemia in myelodysplastic syndromes with granulocyte colony-
stimulating factor plus erythropoietin: results from a randomized phase II study and
long-term follow-up of 71 patients. Blood 1998;92:68-75.
40. Jadersten M, Montgomery SM, Dybedal I, Porwit-MacDonald A, Hellström-
Lindberg E: Long-term outcome of treatment of anemia in MDS with erythropoietin
and G-CSF. Blood 2005;106:803-11.
41. Bowen D, Culligan D, Jowitt S, Kelsey S, Mufti G, Oscier D, Parker J; UK MDS
Guidelines Group. Guidelines for the diagnosis and therapy of adult myelodysplastic
syndromes. Br J Haematol 2003;120:187-200.
42. Musto P, Lanza F, Balleari E, Grossi A, Falcone A, Sanpaolo G, Bodenizza C,
Scalzulli PR, La Sala A, Campioni D, Ghio R, Cascavilla N, Carella AM. Darbepoetin
alpha for the treatment of anaemia in low-intermediate risk myelodysplastic
syndromes. Br J Haematol 2005;128:204-9.
30

43. Greenberg PL. Myelodysplastic syndromes: iron overload consequences and
current chelating therapies. J Natl Compr Canc Netw 2006;4:91-6.
44. Cheson BD, Bennett JM, Kantarjian H, Pinto A, Schiffer CA, Nimer SD,
Lowenberg B, Beran M, de Witte TM, Stone RM, Mittelman M, Sanz GF, Wijermans
PW, Gore S, Greenberg PL. Report of an international working group to standardize
response criteria for myelodysplastic syndromes. Blood 2000;96:3671-4.
45. Cheson BD, Greenberg PL, Bennett JM, Lowenberg B, Wijermans PW, Nimer SD,
Pinto A, Beran M, de Witte TM, Stone RM, Mittelman M, Sanz GF, Gore SD, Schiffer
CA, Kantarjian H. Clinical application and proposal for modification of the
International Working Group (IWG) response criteria in myelodysplasia. Blood
2006;108:419-25.
46. Deeg HJ. Optimization of Transplant Regimens for Patients with Myelodysplastic
Syndrome (MDS). Hematology Am Soc Hematol Educ Program. 2005:167-73.
47. Hofmann WK, Heil G, Zander C, Wiebe S, Ottmann OG, Bergmann L, Hoeffken
K, Fischer JT, Knuth A, Kolbe K, Schmoll HJ, Langer W, Westerhausen M, Koelbel
CB, Hoelzer D, Ganser A. Intensive chemotherapy with idarubicin, cytarabine,
etoposide, and G-CSF priming in patients with advanced myelodysplastic syndrome
and high-risk acute myeloid leukemia. Ann Hematol 2004;83:498-503.
31

48. Cutler CS, Lee SJ, Greenberg P, Deeg HJ, Perez WS, Anasetti C, Bolwell BJ,
Cairo MS, Gale RP, Klein JP, Lazarus HM, Liesveld JL, McCarthy PL, Milone GA,
Rizzo JD, Schultz KR, Trigg ME, Keating A, Weisdorf DJ, Antin JH, Horowitz MM.
A decision analysis of allogeneic bone marrow transplantation for the myelodysplastic
syndromes: delayed transplantation for low-risk myelodysplasia is associated with
improved outcome. Blood 2004;104:579-85.
49. de Witte T, Hermans J, Vossen J, Bacigalupo A, Meloni G, Jacobsen N, Ruutu T,
Ljungman P, Gratwohl A, Runde V, Niederwieser D, van Biezen A, Devergie A,
Cornelissen J, Jouet JP, Arnold R, Apperley J. Haematopoietic stem cell
transplantation for patients with myelodysplastic syndromes and secondary leukemias:
a report on behalfe of the Chronic Leukaemia Working Party of the European Group
for Blood and Marrow Transplantation (EBMT). Br J Haematol 2000;110:620-30.
50. Kolb HJ, Schattenberg A, Goldman JM, Hertenstein B, Jacobsen N, Arcese W,
Ljungman P, Ferrant A, Verdonck L, Niederwieser D, van Rhee F, Mittermueller J, de
Witte T, Holler E, Ansari H; European Group for Blood and Marrow Transplantation
Working Party Chronic Leukemia. Graft-versus-leukemia effect of donor lymphocyte
transfusions in marrow grafted patients. Blood. 1995;86:2041-50.
51. List AF. New agents in the treatment of MDS. Clin Adv Hematol Oncol
2005;3:832-4.
32

52. Silverman LR, Demakos EP, Peterson BL et al. Randomized controlled trial of
azacitidine in patients with the myelodysplastic syndrome: A study of the CALGB. J
Clin Oncol 2002;20:2429-2440.
53. Rüter B, Wijermans PW, Lubbert M. DNA methylation as a therapeutic target in
hematologic disorders: recent results in older patients with myelodysplasia and acute
myeloid leukemia. Int J Hematol 2004;80:128-35.
54. Lübbert M, Wijermans PW. Epigenetic therapy in MDS and acute AML: focus on
decitabine. Ann Hematol 2005;84:1-2.
55. Kantarjian H, Issa JP, Rosenfeld CS et al . Decitabine improves patient outcomes
in myelodysplastic syndromes: results of a phase III randomized study. Cancer.
2006;106:1794-803.
56. Kantarjian H, Oki Y, Garcia-Manero G, Huang X, O'brien S, Cortes J, Faderl S,
Bueso-Ramos C, Ravandi F, Estrov Z, Ferrajoli A, Wierda W, Shan J, Davis J, Giles
F, Saba HI, Issa JP. Results of a randomized study of three schedules of low-dose
decitabine in higher risk myelodysplastic syndrome and chronic myelomonocytic
leukemia. Blood 2006, in press.
57. Sloand EM, Greenberg PL, Wu C, Young, NS, Barrett AJ, Immunosuppressive
treatment is associated with durable responses and a survival advantage in younger
33

patients with Int-1 myelodysplastic syndrome. Proc Am Soc Hematology meeting,
Atlanta, December Blood 2005;106:707a.
58. Saunthararajah Y, Nakamura R, Nam JM, Robyn J, Loberiza F, Maciejewiski JP,
Simonis T, Molldrem J, Young NS, Barrett AJ. HLA-DR15 (DR2) is overexpressed in
myelodysplastic syndrome and aplastic anemia and predicts a response to
immunosuppression in myelodysplastic syndrome. Blood 2002;100:1570-74.
59. List A, Dewald G, Bennett J, Giagounidis A, Raza A, Feldman E, Powell B,
Greenberg P, Thomas D, Stone R, Reeder C, Wride K, Patin J, Schmidt M, Zeldis J,
Knight R; Myelodysplastic Syndrome-003 Study Investigators. Lenalidomide in the
myelodysplastic syndrome with chromosome 5q deletion. N Engl J Med
2006;355:1456-65.
34

Tables
Table 1
Minimal Diagnostic Criteria in MDS*
--------------------------------------------------------------------------------------------------
A. Prerequisite Criteria
- Constant cytopenia in one or more of the following cell lineages:
erythroid (hemoglobin

Table 2
Idiopathic Cytopenia of Uncertain (Undetermined) Significance (ICUS)
--------------------------------------------------------------------------------------------------------------
A: Definition
- Cytopenia in one or more of the following cell lineages (for ≥ 6 months):
erythroid (Hb

Table 3A
Value of Bone Marrow Histology in MDS (and recommended test)
-----------------------------------------------------------------------------------------------------------------
Seperation from AML when smears are contaminated with blood cells (CD34-IHC)
Separation from hypoplastic AML (CD34-IHC)
Separation from Aplastic Anemia
Multifocal accumulations of (CD34+) progenitor cells (CD34-IHC)*
Abnormal distribution/localization of CD34+ progenitor cells, ALIP (CD34-IHC)*
Abnormal accumulation and morphology of megakaryocytes (IHC: CD31, CD42, or CD62)
Demonstration of bone marrow fibrosis (Gömöri´s silver impregnation)
Demonstration of increased angiogenesis (CD34-IHC)
Diagnosis of a second (concomitant) myelogenous neoplasm
Diagnosis of hypocellular MDS
Diagnosis of MDS-U and SM-MDS
Demonstration of cytogenetic markers by in situ-FISH when no karyogram is available**
----------------------------------------------------------------------------------------------------------------
AML, acute myeloid leukemia; IHC, immunohistochemistry; MDS-U, unclassifyable MDS;
SM-MDS, systemic mastocytosis associated with MDS.
*Since abnormal distribution/localization cannot be discriminated from random multifocal
accumulation of CD34+ cells, the proposal is to merge both terms into ´multifocal
accumulation´ of CD34+ cells and to avoid the term ´ALIP´. **Currently, in situ-FISH is not
a standard in the evaluation of (suspected) MDS.
37

Table 3B
Recommended Immunohistochemical Markers in MDS
----------------------------------------------------------------------------------------------
A: Minimal Panel
marker(s) cell type(s)
------------------------------- ---------------------------------------------------
- CD34* blast cells, progenitors, endothelial cells
- CD31 or CD42 or CD62 megakaryocytes
- tryptase* mast cells, basophils, myeloid progenitors
---------------------------------------------------------------------------------------------
B: Extended Panel – according to the cell lineage to be examined
marker(s) cell type(s)
------------------------------- ---------------------------------------------------
- CD3 T cells
- CD15** monocytes, granulocytes
- CD20 B cells
- CD25 T and B cell subset, atypical mast cells
- CD38 plasma cells
- CD68, CD68R** monocytes, macrophages, myeloid cells
- Lysozyme** monocytes, macrophages
- CD117* progenitor cells, mast cells
- 2D7, BB1 basophils
---------------------------------------------------------------------------------------------
*In a very few cases of MDS, blasts cell may be CD34-negative cells. In such
situation, CD117 can be applied as an alternative, whereas tryptase usually is
negative or shows only a weak reactivity with blast cells. ** Monocyte /
macrophage markers may be helpful to discriminate between immature
monocytic cells and blast cells (CMML versus AML). Otherwise, monocytic
markers are not recommended in MDS.
38

Table 4
Recurrent phenotypic abnormalities detected by flow cytometry in MDS
-------------------------------------------------------------------------------------------
CD34+ myeloid progenitors
- absolute and relative increase in CD34+ cells
- expression of CD11b* and/or CD15
- lack of expression of CD13, CD33, or HLA-DR
- expression of ´lymphoid´ antigens: CD5, CD7, CD19, or CD56
- decreased CD45 expression
- abnormal increased or decreased intensity of CD34
- abnormally decreased CD38 expression
CD34+ B cell progenitors (CD34+/CD10+)
- absolute and relative (to all CD34+) decrease in CD34+/CD10+ cells
Maturing myeloid (neutrophil) cells
- hypogranularity as evidenced by decreased right angle light scatter
- abnormalities in relationship patterns of myeloid antigens
- asynchronous maturation
- lack of expression of CD13 or CD33
- expression of CD34
- expression of ´lymphoid´ antigens
- decreased CD45 expression
Monocytes
- abnormalities in relationship patterns of HLA-DR, CD11b, CD13, CD14, CD33
- lack of expression of CD13, CD14, CD16, or CD33
- expression of CD34
- expression of ´lymphoid´ antigens (with the exception of CD4)
Erythroid precursor cells
- abnormal expression of CD45
- expression of CD34
- abnormal expression of CD71, CD117, or CD235a
-------------------------------------------------------------------------------------------
*note (immature) basophils may also coexpress some CD34 with CD11b
39