IN-VITRO PROTEOLYSIS OF THE RED-CELL MEMBRANE IN PATIENTS WITH HIV-INFECTION

It has been suggested that acquired abnormalities of the red cell memb rane due to various injuries [azidothymidine (AZT) therapy, immunoglob ulin coating of red cells, differentiation abnormalities of erythroid precursors] contribute to the onset of anaemia in HIV-infected patient s. In vitro proteolysis of erythrocyte membrane proteins is regarded a s a molecular marker of membrane damage induced in vivo by different a gents. We therefore investigated in vitro proteolysis of ghosts derive d from red blood cells of 30 HIV-infected patients. Considered collect ively, there was no significant increase in in vitro proteolysis in gh osts from anaemic HIV patients. However, a significantly higher degree of in vitro self-digestion of RBC membrane proteins was evident in HI V-infected patients with spleen enlargement, but not in splenomegalic patients suffering from liver cirrhosis. Neither AZT therapy nor the p resence of a positive direct antiglobulin test seemed to be directly a ssociated with increased in vitro protein breakdown. The results seem to suggest damage of the red cell membrane in HIV infection, induced b y injuries on red cells during their prolonged retention inside an enl arged spleen, while it seems unlikely that AZT therapy or immunoglobul in coating of red cells play major roles in red cell damage.