ABSTRACT
To evaluate the sensitivity of mean corpuscular volume [MCV], mean corpuscular haemoglobin [MCH] and red blood cell [RBC] count for screening of beta thalassaemia trait [BTT] in population of Northern Pakistan. Blood samples from more than five hundred patients admitted in Hayatabad Medical Complex Hospital, Peshawar were taken and analyzed by Sysmex KX-21 Haematology Analyzer. MCV <80 fl, MCH <25 pg and RBC count >/= 5.0x10[12]/L were used for detecting BTT. HbA2 and serum ferritin levels were used to confirm the diagnosis. Forty-eight [8.5%] out of 563 subjects studied were found to have low MCV and MCH with normal or slightly raised RBC count. HbA2 and serum ferritin levels confirmed 44 patients as BTT, 03 as BTT with iron deficiency [ID] and one case of iron deficiency anaemia [IDA]. The analysis of the results showed 100% sensitivity and a positive predictive value of 97.9% of this screening procedure. The study concluded that low MCV and MCH in association with slight erythrocytosis is a reliable and sensitive index for screening beta thalassaemia trait