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

fy predictive factors for these abnormalities. Methods. A review of magnetic
resonance imaging of the brain for 50 SCD patients followed in 2
centers specialized in inherited hemoglobin disorders was undergone. Of
those 50 patients, 39 asymptomatic patients have had surveillance brain
MRI. All patients underwent MR imaging at 1.0 T using 5 mms thick sections
and all images were read by a single radiologist with a 10 years
experience in neuroradiology . Fisher’s Exact test (Wilcoxon two sample
rank-sum test) was employed to study the association of binary data
(continuous data)with the 2 groups. The SAS v8.2 (Cary, N.C.) was used
to analyze the data. A p-value less than 0.05 was considered significant.
Results. Overall prevalence of stroke in this group was 30% (15 out of 50).
11 patients (22%), median age 14 years and 6 months, had overt strokes.
When patients with overt stroke were excluded, 4 of the remaining 39
patients (10.3%), median age 13 years and 5 months, had abnormal brain
MR imaging compatible with SCI. Of those with overt strokes, 27%
were females and 73% were males. 91% had SCA and 9% had sickle β
thalassemia (ST). Bivariate analysis showed an association between the
occurrence of overt stroke and premature death (p=0.006), regular blood
transfusions (p=0.006), osteomyelitis (p=0.009) and acute chest syndrome
(p=0.085). As for those with SCI, all 4 patients were males and
were in the SCA group. Bivariate analysis showed an association
between the occurrence of SCI and presentation of disease before 2 years
of age (p=0.053, borderline) and acute chest syndrome (p=0.035). The
small number of patients in this group did not allow for multivariate
analysis. Conclusions. Stroke prevalence rate in Lebanese patients with
SCD is lower than what was previously reported. This may be attributed
to the small study size as well as to the imaging technology utilized
which is less sensitive than newer MRI technology at detecting very
small lesions.
1401
NEONATAL THROMBOCYTOPENIA AND PLATELET TRANSFUSION: OUR EXPERIENCE
S. Misso, 1 L. Paesano, 2 M. D’Onofrio, 2 B. Feola, 1 S. Marotta, 1
E. D’Agostino, 3 G. Fratellanza, 3 A. Fratellanza, 3 A. Minerva1 1 Hospital „S. Sebastiano and S. Anna, CASERTA; 2 Hospital S. Giovanni
Bosco„, NAPLES 3 University, Federico II, NAPLES, Italy
Background. Premature infants and at term newborns have an higher
circulating blood volume per Kilogram than the adults (100 mL/Kg in premature;
80 mL/Kg in at term), for this reason, in case of neonatal thrombocytopenia,
a specific hemocomponent, with a very high Platelet concentration,
needs for transfusion therapy. The laboratory criteria for
Platelet transfusion are the following: A) a PLT count < 150×10 9 cells/L
if bleeding is observed; B) a PLT count < 20×10 9 cells/L without bleeding;
C) a PLT count < 50×10 9 cells/L in newborns showing critical clinical
conditions. Aims. In this study, we have reported the PLT transfusion
therapy in Neonatal Intensive Care Unit (NICU) of Caserta’s Hospital in
the last four years. Methods. Effects of PLT transfusions have been followed
in 37 children (31 premature infants and 6 at term newborns). The
weight of premature infants ranged from 600-1800 g and at term newborn
from 1800-4000 g. Gestation age of premature infants ranged from
26-36 weeks and of at term ones, of course, from 37-42 weeks. For every
Platelet transfusion in these newborns, the volume of Platelet Concentrate
has been of 10-20 mL/Kg, with a PLT count ≤ 700×10 9 cells/L.
Results. In the study period, 77 PLT transfusions have been performed:
23 children have been only transfused one time, while multiple PLT
transfusions (ranged 2-10) needed for 14 children according to clinical
conditions. The observed clinical indications for transfusions have been
the sepsis with haemorrhagic syndrome (26 cases), haemorrhagic syndrome
without sepsis (7 cases) and neonatal alloimmune thrombocytopenia
without haemorrhagic syndrome (4 cases). After 24 hours from
transfusion therapy, the absolute PLT count and the Correct Count Increment
have increased in all 37 little patients. The highest increase in PLT
count was 45×10 9 cells/L, while the lowest 5×10 9 cells/L. No difference
in the efficacy of therapy has been detected between premature group
and at term group. 94% of children has been discharged from hospital
in good general conditions without complications in following controls.
Conclusions. In conclusion, we can affirm that PLT transfusion in premature
infants and in at term newborns is an efficient and safe treatment
of severe haemorrhagic conditions. However a collaboration between
NICU, Paediatric Haematologists and Transfusion Centre is necessary to
choice the adequate Platelet Concentrate’s volume for transfusion and
the best PLT donor for the newborn.
12 th Congress of the European Hematology Association
1402
HEREDITARY HEMOCHROMATOSIS GENE MUTATIONS IN THE SOUTH EASTERN REGION
OF TURKEY
A. Altintas, S. Pasa, T. Cil, B. Devecioglu, O. Ayyildiz
Dicle University Medical Faculty, DIYARBAKIR, Turkey
Background and Aims. Hereditary hemochromatosis (HH) is a common
disorder of iron metabolism with autosomal recessive inheritance and is
characterized by tissue injury resulting from an abnormal accumulation
of iron in various organs. The hemochromatosis protein (HFE) gene was
identified on chromosome 6 by Feder et al. in 1996. Most affected patients
are homozygous for the missense mutation which results in the substition
of tyrosine for cysteine at amino acid 282(C282Y). A more common
mutation is the substition of aspartat for histidine at amino acid 63
(H63D); this mutation may contribute to minor increases in iron levels but
rarely iron overload in the absence of C282Y. S65C missense substitution
accounted for nearly 8% of hemochromatosis chromosomes. Additional
rarer mutations in the HFE gene have since been described, such as the
V53M, V59M, H63H, Q127H, Q283P, P168X, E168Q, E168X, and W169X
mutations. Diagnosis of HH is usually based on a combination of various
genetic or phenotypic criteria. Genetically, it can be based on direct
DNA testing for HFE gene mutations that associated with hereditary
hemochromatosis. Percentage of transferrin saturation and serum ferritin
level have been used to confirm the diagnosis of HH. We conducted a
study to describe the HH mutations in Southeastern region of Turkey.
Patients and Methods. We analyzed the HH mutations of the patients with
high transferrine saturation, and with clinical suspicion or findings that
attributed to HH. Prevalence of HH genes; C282Y, Q283P, H63D, and
S65C, V53M, V59M, Q127H, P160delC, E168Q, E168X, W169X, TFR2;
E60X, M172K, Y250X, AVAQ594-597del, FPN1; N144H, V162 del variants
were analyzed and results were evaluated retrospectively. Results.
Mean ferritine level was 285 ng/mL(196-1936). Transferrine saturation of
70 of 97 patients were between 38-45% and remaining 27 patients have
transferrine saturation of 45-50%. 19 of 97 patients (19,5%) have hetezygote
H63D mutations and no other mutation was detected. These result
is similar to the results of other population based studies that were carried
out in Turkey. Liver biopsy was performed in our 2 patients and no
sign of iron overload was examined. Conclusion. In our medical center all
of the hemochromatosis cases are associated with secondary iron overload
and no patient with HH was detected. Although H63D heterozygosity
is frequent in our population, heterozygosity of this mutation is not
related with iron overload. It would be more reliable to determine the
transferrine saturation cutoff value as higher than 50% , or even 60% for
establishing the contributing role of these mutations in the diagnosis of
HH. The results of other population based studies in our country supporting
our data however further population based studies are required to
confirm this data in our region. We know that there may be major racial
variation in gene polymorphisms. Therefore, population based prevalence
studies must be performed to understand its regional and racial frequency
before using HH mutations as a diagnostic procedure.
1403
RAPID IDENTIFICATION OF HETEROZYGOUS OR HOMOZYGOUS JAK2V617F MUTATION
IN MYELOPROLIFERATIVE DISORDERS USING MELTING CURVE ANALYSIS
C.L. HO, H.M. Hung, P.Y. Chang, T.S. Chen, R. Jen, S.H. Hu,
W.Y. Kao, Y.C. Chen, N.S. Yao, H.F. Lin, Y.Y. Wu, T.Y. Chao
Tri-Service General Hospital, TAIPEI, Taiwan
Background. An activating JAK2 mutation recently has been associated
with a wide spectrum of myeloproliferative disorders (MPD) which
included polycythemia vera (PV), essential thrombocythemia (ET) and
myelofibrosis with myeloid metaplasia (MMM). This newly identified
somatic point mutation is a G-C to T-A transversion, resulting in the substitution
of valine by phenylalanine at codon 617 (JAK2V617F). Mutational
frequencies were the highest for PV (65-97%) followed by ET (32-57%)
and MMM (43-50%). However, 25% of patients with PV displayed
homozygosity for the mutant allele which was infrequent in other
myeloid disorders. Aims. We report the advance and our experience in the
diagnosis of JAK2 mutation in MPD. Methods. In the current study, mutation
analysis for JAK2V617F was performed prospectively either bone
marrow or peripheral blood cells using allele-specific polymerase chain
reaction (AS-PCR) and fluorescence resonance energy transfer (FRET)
probes with melting curve analysis. From January to December of 2006,
we prospectively enrolled 78 patients with PV (N=21), ET (N=32), MMM
(N=5), secondary PV (N=4), secondary thrombocytosis (N=2), acute myelocytic
leukemia (AML) (N=4), chronic myelocytic leukemia (CML) (N=8),
haematologica/the hematology journal | 2007; 92(s1) | 503