Immunogenetic differences in subpopulations of patients with IgA nephropathy (Berger's disease)

Gm and Km as well as HLA-A, HLA-B, and HLA-DR phenotype frequencies were examined in 64 well-defined IgA nephropathy patients. The patients were divided into subpopulations according to clinical symptoms, e.g. macrohematuria and chronic renal failure (CRF). In patients with CRF the frequency of the Gm1,3,17;5,13,21 phenotype tended to be increased (p = 0.016; pcorr = 0.08). The frequency of the HLA-DR phenotype with only one antigen (HLA-DR-) was increased in the whole population (p less than 0.001; pcorr less than 0.011), which appeared to be confined to the patients with macrohematuria (p less than 0.001; pcorr less than 0.01) and non-CRF (p less than 0.001; pcorr less than 0.011). Patients with the Gm1,3,17;5,13,21 phenotype developed a CRF significantly earlier (p = 0.009; pcorr = 0.045) than patients with other Gm phenotypes. These data suggest that clinically observed subpopulations of IgA nephropathy patients differ in immunogenetic background.