الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
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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
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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
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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
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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.