Elevated immunoglobulin G4 level is associated with reduced colectomy-free survival in patients with primary sclerosing cholangitis and ulcerative colitis.

BACKGROUND AND AIM Patients with primary sclerosing cholangitis (PSC) and elevated immunoglobulin (Ig) G4 have been shown to have more severe disease with a shorter time to orthotopic liver transplantation (OLT). The aim of the study was to investigate the clinical outcomes of PSC and UC in patients with elevated serum IgG4. METHODS We analyzed data from 50 patients with PSC and known serum levels of IgG4. They were divided into groups called high IgG4 (>112 IU/L; n = 10) or normal IgG4 (n = 40). We compared the requirement of OLT and colectomy between groups. RESULTS High IgG4 was found in 10 PSC patients (20%). UC was associated in 9/10 patients with high IgG4 vs. 32/40 patients with normal IgG4 (p=0.67). Patients with high IgG4 were younger at PSC diagnosis (28.1 ± 13.9 vs. 37.6 ± 13.4 years, P=0.04), more likely to have backwash ileitis (7/9 vs. 12/32, P < 0.001) and UC flares (median of 5.5 vs. 1.5, P = 0.02). Kaplan-Meier curve analysis showed that patients with elevated IgG4 had reduced colectomy-free survival than patients with normal IgG4 (Log Rank p < 0.001). The median time to colectomy was 5 years from UC diagnosis in high IgG4 group vs. 12 years in the normal IgG4 group (p = 0.01). CONCLUSIONS Elevated IgG4 was seen in a small number of PSC patients. Most of these patients had associated UC, were younger at the time of PSC diagnosis, more likely to have backwash ileitis and had reduced colectomy-free survival than patients with normal IgG4.