12th Congress of the European Hematology ... - Haematologica

ß2GP1 may be considered as determinant cofactors for the developing
risk of antiphospholipid syndrome (APS) or autoimmune diseases in ITP
patients. Moreover, great attention should paid to both assay as predictors
for steroid therapy response. The presence of APA in ITP patients
was not be relevant to the pathogenesis of thrombocytopenia. Nevertheless,
further study are needed to address this important issue because of
the small number of patients in our series.
Figure 1. Results of follow up study for initially presented ITP patients to
show those who developed SLE and their antiphospholipid antibosies status
at start of the study.
1143
IN VIVO AND EX VIVO OXIDATIVE DAMAGE OF ERYTHROCYTE MEMBRANE PROTEINS
IN HEREDITARY SPHEROCYTOSIS AND CPDA PRESERVED RBC: A COMPARATIVE STUDY
A. Kriebardis, 1 P. Margetis, 1 M. Antonelou, 1 K. Stamoulis, 2 F. Karababa, 3
E. Economou-Petersen, 4 A. Loutradi, 3 L. Margaritis, 1 I. Papasideri1 1 University of Athens, ATHENS, Greece; 2 Blood Transfusion Center Nikea,
PIRAEUS, Greece; 3 Center of Thalassemias, ATHENS, Greece; 4 National Blood
Center, ATHENS, Greece
Background. In conditions of increased cellular stress the membrane
and the cytoskeleton of the RBC sustains certain modifications. HS is a
heterogeneous group of disorders with regard to clinical severity, gene
defects and mode of inheritance. The abnormal red cell morphology is
due to a deficiency of, or a dysfunction in, spectrin, ankyrin, band 3 or
pallidin. During storage in anticoagulant media, RBC membrane proteins
undergo progressive alterations, oxidation, cross-linking and
increased hemoglobin association, resembling HS. Aims. To determine
the possible oxidation-related protein alterations and the oxidative index
of the membrane ghosts and cytoskeletons in clinically diagnosed cases
of HS and in CPDA-preserved non-leukodepleted RBCs units during
storage. Methods. Twelve patients with clinical and laboratory diagnosis
of mild (N=5) to typical HS [Sp(-)HS N=4, Sp/Ank(-) HS N=2, ank(-)HS
N=1, B3(-)HS N=4, No(-)HS N=1, splenectomized N=2, concomitant
carriers of α-thalassemia N=2] and twelve healthy subjects used as controls
were examined in addition to RBC concentrates from six eligible
blood units (each RBC unit was followed up during the whole storage
period). Ghosts and cytoskeletons were analyzed by SDS-PAGE densitometry
and probed for hemoglobin, IgG’s and a variety of membrane
proteins using human RBC-specific antibodies. Carbonylated protein
content was determined after 2,4-dinitrophenylhydrazine derivatization
and immunodetection of the DNP moiety. Results. Protein degradation,
formation of high molecular weight aggregates and increased Hb and
IgG’s binding to the membrane were found in the majority of the HS
patients examined, and in RBCs after 4 and 30 days of storage, respectively.
The protein band-8 was also increased in 8/12 HS patients, half
of which have membranes enriched in Hb and in RBCs after 15 days of
storage. Probing of the HS and stored ghost membranes for Hb clarified
that the membrane-associated globin was in the form of probably oxidized/denatured
Hb or hemichromes. Subsequent analysis of the
cytokeletons revealed pathologically increased amounts of skeletonassociated
Hb monomers and high order aggregates, representing globin
oligomers and complexes with membrane protein components, in the
majority of the HS samples (10/12), and in the middle of RBCs storage
period. Immunoblotting with dinitrophenol-specific antibody showed
increased RBC membrane and cytoskeleton protein carbonyls in the
12 th Congress of the European Hematology Association
75% of the HS patients and soon after 10 days of storage in RBC units.
Summary/Conclusions. The RBCs in vivo (HS) and ex vivo (CPDA storage)
are characterized by oxidative alterations both in Hb and a variety of other
membrane components and increased protein carbonylation levels.
The increased binding of oxidized Hb to the membrane is expected to
affect the flexibility of the membrane, to transmit the oxidative potential
in individual membrane proteins and lipids and finally to initiate
band 3 aggregation and other cell surface topography changes that are
associated with events like vesiculation and erythrophagocytosis. These
data corroborate the evidence for the occurrence of oxidative damage in
membrane proteins both in HS and in RBCs storage, adding some new
insight in the field of HS pathophysiology, as well as of the causes underlying
the clinical variability of the disease.
1144
SEVERE THROMBOCYTOPENIA INDUCED BY PEGYLATED (PEG)-INTERFERON (IFN) PLUS
RIBAVIRIN IN HEPATITIS C PATIENTS
J.N. Rodriguez, G. Rodriguez, E. Martin, M.V. Moreno, A. Palma,
J.C. Dieguez, J.A. Quesada, A. Amian, A. Fernandez-Jurado
Hospital „Juan Ramon Jimenez„, HUELVA, Spain
Background. The combinated therapies with interferon (pegylated or
not) and ribavirin are the standard treatment of chronic hepatitis C and
are associated with a high rate of sustained virologic response. Ribavirin
is directly toxic to red blood cells and is associated with hemolysis while
mild to moderate thrombocytopenia (and neutropenia) is a common
adverse effect of interferon being, this circumstance, usually adscribed
to bone marrow suppression. However, severe cases of thrombocytopenia
have been very rarely reported in the literature. We present the cases
of 2 patients who developed severe thrombocytopenia after beginning
treatment with the combination of PEG-IFN and ribavirin. CASE 1: A 35year-old
man developed severe thrombocytopenia 9 months after beginning
PEG-IFN and ribavirin combination for chronic hepatitis C. Platelet
(Plt) counts fell up to 1×109 /L. No hemorrhagic complications were
observed. In bone marrow megakaryocytes were slightly decreased.
PEG-IFN and ribavirin were stopped and i.v. immunoglobulins were
started achieving a moderate but not sustained response (Plt 51×109 /L)
with subsequent fall (Plt 8×109 /L). Corticosteroids (prednisone 1
mg/Kg/day) were later used obtaining a complete and sustained response
(3 months after treatment cessation). CASE 2: A 35-year-old woman
developed severe thrombocytopenia 10 months after beginning PEG-
IFN and ribavirin combination for chronic hepatitis C. Plt counts fell up
to 4×109 /L. The patient presented metrorrhagia and platelet transfusions
were administered twice without significant recovery. In bone marrow
megakaryocytes were reduced. Antiplatelets antibodies were positive.
PEG-IFN and ribavirin were stopped and i.v. immunoglobulins were
started achieving a moderate but not sustained response (Plt 23×109 /L)
with subsequent fall (Plt 6×109 /L). Corticosteroids (prednisone 1
mg/Kg/day) were later used obtaining a complete and sustained response
(12 months after treatment cessation). Conclusions. Although very rare,
PEG-IFN can produce severe thrombocytopenia. The mechanism of production
could be variable but severe bone marrow suppression is rare
and immune phenomena should be suspected in severe thrombocytopenia.
The treatment of these cases could be performed with the classical
options for idiopathic thrombocytopenic purpura however, in our experience,
i.v. immunoglobulins do not produce sustained responses, and the
best approach of treatment should be corticosteroids.
1145
IMPROVED β-THALASSEMIA GENOTYPING BY MEANS OF POPULATION-SPECIFIC
REVERSE-HYBRIDIZATION TESTSTRIPS
H. Puehringer, 1 H. Najmabadi, 2 W. Krugluger, 3 H.-Y. Law, 4
V. Viprakasit, 5 C. Oberkanins1 1 ViennaLab Diagnostics GmbH, VIENNA, Austria; 2 Social Welfare and Rehab.
Sciences Univ., TEHRAN, Iran; 3 Dept. Clin. Chem, Rudolfstiftung Hosp.,
VIENNA, Austria; 4 KK Women’s and Children’s Hospital, SINGAPORE, Singapore;
5 Siriraj Hospital, Mahidol University, BANGKOK, Thailand
Background. β-thalassemia is among the most common inherited diseases
throughout the Mediterranean area, parts of Africa, the Middle
East, India and Southeast Asia. Mutations in the β-globin gene may lead
to structural abnormalities (e.g. Hb S, Hb E, Hb C) or to haemoglobin
imbalance due to the reduced synthesis or complete absence of β-globin
chains. In each at-risk population β-thalassemia results from a limited
number of common mutations and a larger, more variable number of rare
mutations. Aims. Based on a previous reverse-hybridization assay (Beta-
haematologica/the hematology journal | 2007; 92(s1) | 421