Immunoglobulin GM and KM allotypes in systemic lupus erythematosus

Genetic variation in immunoglobulin gamma (GM) and kappa (KM) chains was as sociated with systemic lupus erythematosus (SLE) in some studies. However, the data are conflicting, and only one study examined associations in Afric an-Americans. We examined GM and KM allotypes, by race, in a population-bas ed case-control study of SLE. Sera from patients (n = 222) and controls (n = 273) were typed for GM and KM allotypes by a hemagglutination inhibition method. GM phenotypes were not significantly associated with SLE in African -Americans or Caucasians. However, the frequency of KM phenotypes in Caucas ian patients was significantly different from that in controls (p = 0.032). KM3,3 was associated with an increased risk, whereas KM1,3 was associated with a lower relative risk of SLE. In African-Americans, however, the patte rn of associations with KM phenotypes differed from that in Caucasians, and the overall difference between patients and controls was not statistically significant. Copyright (C) 2001 S. Karger AG, Basel.