Flow cytometric determination of zeta globin chian in red blood cells

Abstract

z-globin chain is a globin protein synthsized during the first 2 months of gestation to about 3 months after birth. Without appropriate technique, no z-globin chain could be detected in normal adult but the level is increased in individual with a-thalassemia.  In this study, a technique of flow cytometry has been applied to determination of z-globin chain in red blood cells. The z-globin chain in red blood cells was detected using MoAb - z globin – RPE. Study was done on normal individuals, a-thalassemia 1 carriers (SEA deletion) and a-thalassemia disease. The levels of z-globin chain were found to be 1.0 ± 0.7 % in 6 normal individuals, 9.0 ± 2.0 % in 6 a-thalassemia 1 carriers and 9.2 ± 6.4 % in 4 double heterozygote for a-thalassemia 1 with Hb E. The levels of 14.3 % and 13.9 % were detected in two patients with Hb H disease whereas a fetus with Hb Bart’s hydrops fetalis had z-globin chain of as high as 68.0 %. This data indicates that flow cytometric assay could be used to demonstrate z-globin chain in red blood cells and the amounts detected are correlated with number of a-globin defect. With further development, the technique might be useful for screening and diagnosis of a-thalassemia in a prevention and control program.