[Osmotic resistance of erythrocytes as a screening method in detecting heterozygotes in beta-thalassemia]

Osmotic fragility of red blood cells in three different buffered solutions, i.e. 0,32%, 0,36% saline and 0,40% Tyrode solution was studied as a screening test for the detection of beta-thalassemia trait. 90 genetically designated beta-thalassemia heterozygotes were studied for the screening tests. In addition 514 school children and 161 patients suffering from anemia of different etiology were also examined for the osmotic fragility screening. The results of the studies indicated that the one tube method screening test with 0.36% buffered saline solution was the appropriate solution in screening for beta-thalassemia trait since the solution was able to detect 99 to 100% of the carriers. However, about 15% of normal individuals were also found to give a false positive for the 0.36% saline screening test. It is recommended that 0.36% buffered saline solution be used as a first screening test for the detection of beta-thalassemia trait since it is simple, rapid, cheap and applicable. Those who are positive with this test are required to be completely studied in hematology for the final diagnosis of either beta-thalassemia trait or other hematologic disorders.