BLOOD-GROUP-B GLYCOSPHINGOLIPIDS IN ALPHA-GALACTOSIDASE DEFICIENCY (FABRY DISEASE) - INFLUENCE OF SECRETOR STATUS

Defect in degradation of blood group B-immunoactive glycosphingolipids in Fabry disease (deficiency of lysosomal alpha-galactosidase EC 3.2. 1.22) has been studied using highly sensitive and specific TLC-immunos taining analysis of urinary sediments and tonsillar tissues of blood g roup B patients and healthy controls, secretors and nonsecretors. The B glycolipid antigens with hexasaccharide chains were consistently fou nd increased (25- to 100-fold) in the urinary sediments of three Fabry patients, blood group B or AB secretors. Conversely, they were absent in the urinary sediment of one blood group B nonsecretor patient. In normal secretors, B glycosphingolipids were present only in traces. Mo reover, significant increase in B glycolipid antigens (8-fold) was fou nd in the tonsillar tissue of a Fabry patient blood group B secretor. We conclude that the secretor status is responsible for increased conc entration of blood group B glycosphingolipids in both urinary cells an d tonsils in alpha-galactosidase deficiency. The quantity of stored B- immunoactive glycosphingolipids, however, is much lower than that of t he mainly accumulated glycosphingolipid Gb(3)Cer. The results clearly indicate that active or silent Se gene, which controls synthesis of B- antigen precursors, is responsible for notable difference in B-glycosp hingolipids expression in Fabry patients - secretors and nonsecretors. Whether this novel aspect may be of prognostic significance, remains to be established. (C) 1997 Elsevier Science B.V.