Transient reduction in erythrocyte membrane sialoglycoprotein beta associated with the presence of elliptocytes.

Erythrocyte membranes from an anaemic patient receiving gold therapy for rheumatoid arthritis had reduced beta-sialoglycoprotein (beta-SGP) content but normal expression of sialoglycoproteins alpha, delta and gamma. Elliptocytes were present in the peripheral blood. The serum of the patient contained anti-beta-SGP which did not appear to bind to her own cells. It reacted with all erythrocytes apart from beta-SGP deficient Leach phenotype cells. The antibody was inhibited by purified beta-SGP from normal red cells, bound to beta-SGP on immunoblots and also reacted with the abnormal beta-related-SGP in erythrocyte membranes of both the Gerbich type and Yus type of Gerbich negative. Two years later the patient was no longer anaemic, no elliptocytes were seen in her peripheral blood film and her erythrocyte membranes had normal beta-SGP content. Antibody was no longer present in her serum and antibody from the earlier sample now reacted with the patient's erythrocytes. Erythrocyte membrane beta-SGP is known to be important in the maintenance of normal cell shape. It is likely that the transient occurrence of elliptocytes in the patient resulted from the concurrent temporary reduction in beta-SGP content of her erythrocyte membranes.