الفهرس | Only 14 pages are availabe for public view |
Abstract The thalassemias are inherited disorders of Hb synthesis their clinical severity widely varies, ranging from asymptomatic to severe or even fatal entities. It is divided into three groups: the severe transfusiondependent (major) varieties; the symptomless carrier states; and a group of intermediate severity thalassemia intermedia. The beta-thalassemias are inherited in an autosomal recessive manner. Β-thalassemia trait often shows microcytosis, a normal or an increased RBC count, and an elevated level of HbA2, which provides the basis for laboratory screening. Beta thalassemia trait is an important differential diagnosis of iron deficiency anemia (IDA) typically, the blood count and peripheral blood film exhibit features similar to those seen in iron deficiency anemia. In this study, we investigated microcytosis in healthy adult blood donors in Egypt then Hb electrophoresis was done to samples with MCV less than 78 fl to predict prevalence of BTT among them and differentiating it from IDA and the results was as follows: Summary -98- Prevalence of BTT in this study was 6%, while IDA represented 4.5% of total 200 samples investigated. The cut off value of MCV between them was 73 fl with 91.7 sensitivity and 100% specificity. RDW at level ≤14.5 can differentiate BTT from IDA with 83.3 sensitivity and 100% specificity. RBCs count at value > 5.47 can differentiate BTT from IDA with 100 %sensitivity and 100% specificity. Conclusion and Recommendations -99- Conclusion β thalassemia trait and IDA are the most common causes of microcytosis in healthy adult blood donors. Prevalence of β thalassemia trait is 6% among healthy adult blood donors in Egypt, while IDA represents 4.5% among them. Donors with BTT have Hb values comparable to normal so they are accepted for donation and escape diagnosis. The cut off value of MCV between β TT and IDA was 73 fl with 91.7 sensitivity and 100% specificity. RDW at level ≤14.5 can differentiate BTT from IDA with 83.3 sensitivity and 100% specificity. RBCs count at value > 5.47 can differentiate BTT from IDA with 100 %sensitivity and 100% specificity. The cutoff values of MCV ≤73fL, RBC count > 5.47x 1012/L, and RDW ≤14.5% were suggested to be associated with a high probability of BTT while this values may differ in different groups of population. Conclusion and Recommendations -100- Recommendations Further studies on bigger numbers of donors or even general population may be of value in predicting prevalence of thalassemia trait in Egypt. Complete blood count (CBC) should be done before blood donation and microcytic samples should be analyzed otherwise; donors with β thalassemia trait will be accepted for donation and escape diagnosis. |