Altered sialic acid contents of red blood cell membrane preparations in homozygous beta-thalassemia.

In the present work the sialic acid content of the red blood cell ghost membranes was measured in blood specimens obtained from 18 patients with beta-thalassemia major and 10 controls. The sialic acid-protein weight ratio was reduced in comparison with normal mean value only in four patients who had undergone splenectomy several years ago. The remaining 14 unsplenectomized patients showed a sialic acid/protein ratio that was 50% higher than normal (P less than 0.001). The titratable sulphydryl groups were also measured in red blood cell membrane preparations. SH groups content was reduced in patients with beta-thalassemia major, and a dramatic decrease (-60%) was observed in patients after splenectomy.