Variability of the antigenicity of the glomerular basement membrane in nail-patella syndrome.

The difficulty of diagnosing Alport-type nephritis, and the possibility of altered antigenicity of the glomerular basement membrane in Alport-type nephritis is discussed. Attention is focused on the monoclonal antibody MCA-Pl as a specific tool in studying the Goodpasture antigenetic determinant in renal biopsy specimens. The clinical details and the results of MCA-Pl binding studies for three patients with nail patella syndrome are presented. Two of these patients proved to have an abnormal antigenicity of the glomerular basement membrane as demonstrated by the absence of binding of MCA-Pl. This is the first time that such an abnormality has been demonstrated in patients other than those with Alport-type nephritis. The significance of these results is discussed.