Molecular and Hematological Characterizations of Acquired Alpha Thalassemia among Sudanese Leukemic Patients

Abstract

Abstract Background Acquired alpha thalassemia (hemoglobin H (I-lbH) disease) is a rare complication of neoplastic chronic myeloid disorders especially myelodysplastic syndrome and other types of leukemia. The association between alpha thalassemia and leukemia type or prognosis is defined by the presence of HbH inclusion which indicated by down regulation of alpha globin gene expression. Objective This study aimed to determine the frequency of the acquired alpha thalassemia (HbH disease) among Sudanese leukemic patients and studying the hematological and molecular characteristics features of this disorder. Materials and methods This descriptive study include 135 Sudanese leukemic patients having a different type of leukemias, male and female with various age groups was enrolled in different hematological and molecular tests. One blood sample was collected in (EDTA) anticoagulated container from each patient in order to perfonn a complete blood count, HbH detection and for molecular analysis. The CBC was perfonned by automated (Sysmex 21), and leishman stained blood films was examined to confinn the type of associated anaemia. Blood films also prepared with BCB stain were used to detect HbH containing cells. RNA was extracted from the samples with positive HbH, converted to cDNA and analyzed for alpha beta globin ratio using Real Time RT-PCR. Results: A total of 129 samples from Sudanese leukemic patients enrolled in this study for quantitation of alpha\beta ratio, HbH preparation and CBC. The frequency of the anemic patients among the population was 81.4 %, the NN anemia represents (58.9%) of the total anemic patients, the MH and MN showed 39.5%, 1.6% respectively. The frequency of HbH inclusions among the study population was 27. % positive sample, the positive HbH preparation among each type of leukemia showed a higher frequency in AML (40.6%) followed by (35.0%) in CML while showed lower results in lymphoid l