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

12 th Congress of the European Hematology Association
er lesions. PLL is fatal but relatively chemotherapy-sensitive. The introduction
of more intensive chemotherapy plus/minus localized radiation
might achieve long-term complete remission with better survival rates.
The role of consolidation radiation therapy following local control
should be evaluated.
1418
ANGIOGENESIS MARKERS AND JAK2 MUTATION IN PATIENTS WITH POLYCYTHAEMIA
VERA AND ESSENTIAL THROMBOCYTHAEMIA
S. Theodoridou, 1 E. Mandala, 1 T. Vyzantiadis, 2 M. Speletas, 3 I. Venizelos,
1 V. Garypidou1 1 Hippokration Hospital, THESSALONIKI, Greece; 2 Aristotle University1st
Microbiology Dep, THESSALONIKI, Greece; 3 Papageorgiou Hospital, THES-
SALONIKI, Greece
The role of the acquired mutation of the tyrosine kinase JAK2 (V617F)
in human myeloproliferative disorders is under investigation. There is
evidence that the mutation arises as a secondary genetic event and we
now know that has got a key role in signal transduction from multiple
haemopoietic growth factor receptors. The mutation is noted in more
than half of patients with myeloproliferative disorders (MPDs), and in
95% approximately of patients suffering from Polycythaemia Vera (PV).
Recent studies have determined that the JAK/STAT pathway is involved
in mediating processes related to angiogenesis. VEGF whose receptor is
a receptor tyrosine kinase, has surprisingly been shown to activate specific
STATs. We tried to investigate the role of the existence of the mutation
JAK 2 (V617F) mutation in MPDs and its relation with angiogenesis
markers in 17 patients with MPDs (5 with Polycythemia Vera and 12
with Essential Thrombocythaemia, ET). The angiogenesis process in all
patients have been examined by the microvascular density (MVD) count
per 400x high power field (HPF)using light microscopy of bone marrow
trephines immunostained with anti-CD34 monoclonal antibody and
with the estimation of angiogenesis markers in serum by enzyme
immunoassays. The angiogenic factors estimated were VEGF (vascular
endothelial growth factor), Angiogenin and MMP-9 (matrix metalloproteinase
9). The patients enrolled were divided in two groups according
to the presence or not of the mutation JAK2 (V617F). In our group of
patients the mutation was found in three patients with PV and in six
patients with ET while it was not found in two patients with PV and in
six patients with ET. We found no differences in MVD, VEGF, Angiogenin
and MMP-9 levels among carriers of the mutation and carriers of
the wild type gene. More specifically, MVD count was found 9,1 ±7 vs
7,9±4,2 vessels per HPF, among V617F carriers and the wild type carriers
respectively (p=0,74). VEGF serum levels were found in the subgroup
of V617F carriers 289,9±515,5 vs 278,7±254 pg/mL (p=0,28).
Angiogenin levels were found as 400,3±83,1 vs 326,2±102,2 pg/mL
(p=0,56) among (V617F) carriers and wild type carriers respectively.
Finally MMP-9 levels were found 420,4±364,9 vs 601,2±244,6 pg/mL,
(p=0,28) among (V617F) carriers and wild type carriers respectively. Our
data although preliminary give evidences that the presence of the presence
of the JAK2 (V617F) mutation is not probably involved in angiogenesis
procedure in MPDs. Of course the role and the aetiology of
increased angiogenesis in MPDs is under investigation as well as the
novel molecular marker, the JAK 2 (V617F).
1419
MDM2 PROTEIN EXPRESSION IN PERIPHERAL BLOOD MONONUCLEAR CELLS
OF CHILDREN WITH ACUTE LYMPHOBLASTIC LEUKEMIA IN RELATION TO INITIAL
WHITE BLOOD COUNT
T. Ociepa, E. Maloney, E. Kamienska, T. Urasinski, E. Urasinska
Pomeranian Medical University, SZCZECIN, Poland
Background. White blood count (WBC) at presentation is the one of
most significant prognostic factor in children with acute lymphoblastic
leukemia (ALL). Elevation of initial WBC over 50000/µL, seen in over
20% of children with ALL is uniformly associated with poor prognosis.
High WBC may result from ineffective spontaneous apoptosis which
does not counterbalance increased proliferation of leukemic cells. Both
proliferation and apoptosis are controlled by P53 gene. MDM2 protein
is a known endogenous inhibitor of p53 protein. This study was undertaken
to assess in a clinical setting the hypothesis that overexpression of
MDM2 protein in leukemic cells of children with ALL may be associated
with high initial WBC. It was comprised of 35 children (15 girls, 20
boys, aged 6-192 months, median 95 months) with de novo ALL. All children
were treated according to BFM ALL 90 protocol. The follow up time
was 1-42 months (median 21 months). Methods. Peripheral blood
508 | haematologica/the hematology journal | 2007; 92(s1)
mononuclear cells were collected prior to and after 6 and 12 hours from
prednisone administration. Cytospin preparations of these cells were
stained with mouse monoclonal anti-MDM2 antibodies (DakoCytomation)
followed by goat anti-mouse antibodies conjugated with APC (Molecular
Probes) and mouse monoclonal anti-p53 antibodies conjugated
with FITC (DakoCytomation) respectively. Nuclear DNA was stained
with propidium iodide (PI). MDM2 - associated long red fluorescence and
p53-associated green fluorescence and were measured by laser scanning
cytometer (LSC, CompuCyte, USA). In order to assess rates of apoptotic
cells respective slides were stained with polyclonal rabbit anti-PARP
p85 fragment followed by FITC conjugated swine anti-rabbit antibody.
Cell expressing p89 fragment of PARP were considered apoptotic. Red
fluorescence of DNA-bound PI was used as a contouring parameter. Values
of long red integrated fluorescence and green integrated fluorescence
were recorded as .FCS 3.0 files by WinCyte 3.4 software. Results. The
mean pretreatment values of MDM2 expression were lower in the group
of patients with initial WBC below 50000/µL. (p=0,056). After 12 hours
from prednisone administration these patients had significantly higher
mean p53 expression values (p=0,047) as well as significantly higher rates
of apoptotic cells (p=0,03). They also did better with p-EFS significantly
higher than for those with initial WBC over 50000/µL (0,961 vs 0,667;
p=0,018). Conclusions. These data seem to indicate that preatreatment
overexpression of MDM2 protein may contribute to high initial WBC in
children with ALL. It may also inhibit apoptosis in response to prednisone
treatment, thus influencing the outcome in these patients.
1420
COMBINED SYSTEMIC AND LOCAL TREATMENT OF DISSEMINATED BRAIN
ASPERGILLOSIS IN A 14-YEAR-OLD GIRL WITH APLASTIC ANEMIA AFTER MUD HSCT
T. Ociepa, E. Maloney, T. Urasinski, E. Kamienska, L. Sagan
Pomeranian Medical University, SZCZECIN, Poland
In spite of advances in diagnosis and treatment, invasive aspergillosis
in immunocompromised patients still remains a problem in clinical practice.
The worst prognosis is associated with central nervous system
aspergillosis with a mortality rate exciding 90%. This high rate of treatment
failure results from limited penetration of most of the antifungal
agents through the blood brain barrier. We report on a case of a 14-yearold
girl with congenital aplastic anemia, who at the age of 12 underwent
hematopoietic stem cell transplantation from a matched unrelated
donor. She achieved hematologic reconstitution, however she developed
chronic graft versus host disease treated with glucocorticoids and
cyclosporin A. The post-transplant period was complicated by pulmonary
aspergillosis which was succesfully treated with liposomal
amphotericin B. Twelve months later she developed sudden loss of consciousness,
seizures, diplopia and left-sided hemiparesis. A brain MRI
revealed several disseminated lesions with the two biggest lesions located
in the parietal and frontal lobes (Figure 1).
Figure 1.
A lung CT scan revealed the reactivation of pulmonary aspergillosis.
A galactomannat test was positive. The patient was given intravenous