IgG4 subclass and gamma-glutamyl transferase in children with ulcerative colitis with primary sclerosing cholangitis and without sclerosing cholangitis

Aim of the study
Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease which could be associated with inflammatory bowel disease (IBD), particularly ulcerative colitis (UC). The aim of this study was to compare GGT and IgG4 levels among children with UC with PSC and without PSC.

Material and methods
In this cross sectional study children with UC with PSC and UC without PSC were included. Serum immunoglobulin G4 (IgG4) and gamma-glutamyl transpeptidase (GGT) levels of the 90 UC patients with and without concomitant PSC were measured. Children with serum IgG4 concentration > 175 mg/dl were considered to have elevated IgG4.

Results
Elevated serum IgG4 was found in 8 of 30 (26.6%) patients with PSC vs. 3 of 60 (5.0%) patients without PSC. Compared with the group without symptoms of PSC, the group with PSC showed significantly higher levels of aspartate aminotransferases (AST; 22.5 U/l vs. 70.0 U/l, p < 0.001), alkaline phosphatase (ALP; 359.0 U/l vs. 602.0 U/l, p < 0.001), and IgG4 (56.0 vs. 73.0, p = 0.02). The odd ratio of the elevated IgG4 and GGT in predicting PSC was 6.9 (95% CI: 1.6-28.4) and 18 (95% CI: 5.7-55.9), respectively.

Conclusions
AST, alanine aminotransferase (ALT), GGT, ALP, and serum IgG4 were significantly higher in UC patients with sclerosing cholangitis (SC) compared to UC patients without SC. GGT and IgG-4 measurements are recommended for evaluation of UC.