Membranous Nephropathy and a TAP1 Gene Polymorphism

To the Editor: Membranous glomerulopathy, which is characterized by immune-complex deposits on the epithelial side of the glomerular basement membrane, is one of the most frequent forms of glomerulopathy. The mechanisms responsible for abnormal antibody responses and immune-complex catabolism in this disease are unknown. Nevertheless, an association between membranous nephropathy and the HLA-DR3 class II antigen has been described¹. Recently, two “new” genes (TAP1 and TAP2) have been mapped within the HLA class II region². Each of these genes codes for a transmembrane protein located within the membrane of the endoplasmic reticulum. The noncovalent association of these two . . .