GC and C3 serum groups in ulcerative colitis.

The phenotypes and allele frequencies of two serum protein systems (GC and C3) were studied in 91 consecutive patients with ulcerative colitis and compared with healthy controls. No significant differences were found as far as GC was concerned. However, significant differences were observed in C3: the C3*F allele and C3FS phenotype were more frequent in patients than in controls.