ASSOCIATION OF ALPORTS-SYNDROME WITH HLA-DR2 ANTIGEN IN A GROUP OF UNRELATED PATIENTS

A few family studies have evaluated HLA antigens in Alport's syn drome ; however, there are no large population studies. In the present repor t, we studied 40 unrelated white patients with Alport's syndrome seen at the Unit of Renal Transplantation, Faculty of Medicine of Ribeirao Preto, Sao Paulo, Brazil. HLA-A, -B, -DR and -DQ antigens were typed u sing a complement-dependent microlymphocytotoxicity assay. A control w hite population (N = 403) from the same geographical area was also typ ed for HLA antigens. Although the frequencies of HLA-A and -B antigens of patients were not statistically different from controls, the frequ ency of HLA-DR2 antigen observed in patients (65%) was significantly i ncreased in relation to controls (26%; P<0.001). The relative risk and etiologic fraction for HLA-DR2 antigen were 5.2 and 0.525, respective ly. Although few immunological abnormalities have been shown in Alport 's syndrome, in this report we emphasize the association of HLA molecu les and Alport's syndrome. Besides the well-known inherited molecular defects en coded by type IV collagen genes in Alport's syndrome, the m ajor histocompatibility alleles may be in linkage disequilibrium with these defective collagen genes.