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

acute leukemia. However, we cannot say based on these results whether
this association corresponds to a pre-leukemic event (i.e. certain blood
groups as risk factors) or a consequence of malignancy per se. Using newborn
cord blood for ABO blood group determination with re-determination
of blood groups at intervals in a prospective cohort study is an
idea for future research to evaluate the role of blood groups as risk factors
of leukemia.
1407
ANTITHYMOCYTE GLOBULIN FOR GRAFT-VERSUS-HOST DISEASE PROPHYLAXIS AFTER
MISMATCHED UNRELATED PERIPHERAL BLOOD STEM CELL TRANSPLANTATION FOR
ACUTE MYELOGENOUS LEUKEMIA
J.-W. Lee, H.-J. Kim, W.-S. Min, K.-S. Eom, B.-S. Cho, S.-Y. Kim,
C.-K. Min, S. Lee, S.-G. Cho, D.-W. Kim, C.-C. Kim
Catholic HSCT Center,St. Mary’s Hospital, SEOUL, South-Korea
Background. Anti-thymocyte globulin (ATG) has been introduced in
preventing acute graft-versus-host disease (AGvHD) in several studies.
Many of them suggest that ATG reduces the risk of severe AGvHD but
increases the risk of infections. Aims. We tried to investigate the role of
ATG in HLA-mismatched unrelated hematopoietic stem cell transplantations
(uHSCT), specifically in patients who received G-CSF mobilized
peripheral blood stem cells (PBSCs) or from allele(s)/antigen mismatched
unrelated donors. Methods. Thirty five patients with intermediate to
unfavourable risk AML who received HLA-mismatched uHSCT from
the available Asian as well as Caucasian donors were retrospectively
reviewed. We compared 2 different groups according to the use of ATG
(group 1) or not (group 2). The addition of ATG (thymoglobulin, Sangstat),
at a dose of 1.25 mg per kilogram of body weight per day for 2 consecutive
days, for recipients who received PBSCs from mismatched unrelated
donors (group 1, N=10); this was added to prevent the development
of AGvHD together with our standard regimen which consisted of
methotrexate (10mg/m2 intravenously bolus on day +1; and methotrexate
5 mg/m2 intravenously bolus, on days +3, +6, +11) and tacrolimus
starting at day -1. G-CSF was administered in all patients at a dose of 5
ug/kg subcutaneously per day from D+7 after transplantation until neutrophil
recovery. The median age was 36 (range, 16-53) and the median
follow-up duration was 21 months (range, 5-60). The majority of patients
had intermediate or unfavourable cytogenetic features. The main conditioning
regimen consisted in cyclophosphamide plus total body irradiation.
Results. All transplanted patients were successfully engrafted. The
overall incidence of AGvHD and chronic GvHD was 34% and 40%; 30%
and 33%, 36% and 44% for patients with group 1 and group2, respectively.
Four (11%) patients were relapsed so far. The comparison of estimated
probability of disease-free survival rate at 2-year for each group
was 100% vs 74%, respectively. When we considered the incidence of
transplant-related mortality (TRM) between two groups, there was a significant
difference of event-free survival rate, i.e. 86% vs 47%, respectively.
The overall 2-year non-relapse TRM was 26%. Conclusions. These
results demonstrate that the uHSCT performed with an appropriate dose
of ATG, specifically either from mismatched multinational donors allografted
with PBSCs, are associated with a favourable outcome.
1408
COAGULATION DISORDERS AND INHIBITORS OF COAGULATION IN CHILDREN:
CASES FROM MANSOURA, EGYPT
N. Abdelrazik, 1 H. Ghoniem, 2 T. Selim, 2 L. Tharwat2 1 Mansoura University Children Hospital, MANSOURA, Egypt; 2 Mansoura
Faculty of Medicine, MANSOURA, Egypt
Background. Disorders of coagulation in children provide an interesting
challenge to the medical care team. Aim of the Study. to assess spectrum
and prevalence of coagulation disorders among children attending
Mansoura University Children Hospital (MUCH), Mansoura, Egypt.
Subjects and Methods. A total of 105 pediatrtc patients were referred to
MUCH. They were divided into 2 groups: congenital coagulation disorders
(75 cases, age 45.36±48.59 mo), and acquired coagulation disorders
(30 cases, age 56.13±61.61 mo). All patients were subjected to thorough
history taking including the nature of bleeding, family, past history, mode
of inheritance, and detailed physical findings. Hemostatic tests include:
Platelet count, Bleeding time(BT), Prothrombin time (PT), Activated partial
thromboplastin time (APTT), Thrombin time (TT). Specific tests in
the congenital group include assay of coagulation factors according to
each disorder, Von Willebrand factor assay, Ristocetin aggregation test,
APTT mixing study for detection of inhibitors in complicated hemophilia
cases, F VIII C to VWAg ratio with cut off 0.7 for detection of car-
12 th Congress of the European Hematology Association
riers in some hemophilia A families. Results. Congenital disorders constituted
71.4% of the studied cases versus 28.6% for acquired disorders.
Hemophilia A (42.85%), hemophilia B (14.28%) and liver diseases
(14.28%) represented the majority of the studied cases. Mild and moderate
cases of hemophilia A and B are more frequent than severe cases
in both types. Male sex is more frequent than female in congenital group
(94.7% v 5.3% p