The presence of anti-KIR-autoantibodies reacting with >3 KIRs was associated with an increased disease activity (p < 0.0001), elevated serum levels of IFN-α (p < 0.0001), nephritis (p = 0.001), and the presence of anti-Sm (p = 0.007), and anti-RNP (p = 0.003) autoantibodies in serum. This evidence concerns the gene RNPC3 and nephritis.