Predictive value of a new osmotic test in the screening of heterozygous β thalassemias

Abstract

A new osmotic test (time for 50% haemolysis in standard solution) has been applied in patients affected with heterozygous β thalassemia in a population consisting of 19 thalassemic patients, 15 sideropenic patients, and 52 controls. The same population was examined for heterozygous β thalassemia using electronic measurement of the erythrocyte indices. Sensitivity, specificity, predictive value and efficiency of the two tests were calculated. Statistical analysis did not show any significant differences in sensitivity and specificity between the two methods. The authors conclude that the osmotic test is sensitive, reliable and rapid; it seems to be a valid substitute for electronic haematology analysers in countries where they are not available.

Key Words:

• osmotic fragility
• screening test for thalassemia
• thalassemia