Review of primary sclerosing cholangitis with increased IgG4 levels

Table 1 Studies evaluating serum IgG4 in primary sclerosing cholangitis patients

Ref.	Study design	Location	No. of PSC patients	Percentage (%) with high serum IgG4	Key findings in PSC high IgG4
Mendes et al[15], 2006	Retrospective case control study	United States	127	9%	Higher bilirubin, ALP and PSC Mayo risk score, lower IBD and shorter time to liver transplantation
Zhang et al[16], 2010	Retrospective cohort study	United States	81	22%	Serum IgG4 levels correlated with tissue IgG4 infiltration in liver explants
Bjornsson et al[17], 2011	Retrospective cohort study with prospective follow-up of PSC high serum IgG4	Sweden	285	12%	Presented with jaundice, both intra and extra hepatic strictures, and pancreatic disorders. 50% had cirrhosis. Biochemical response to steroids (n = 12/18). Steroid side effects (39%)
Alswat et al[18], 2012	Retrospective cohort study	Canada	101	22%	Male gender, High ALP, High PSC Mayo Risk Score, Pancreatitis, Previous biliary intervention, Abnormal pancreatic imaging
Culver et al[19], 2012	Retrospective cohort study with prospective follow-up of PSC high and normal IgG4	United Kingdom	194	14%	14% of 186 patients. Worse clinical outcome including liver transplantation and progression of liver disease
Parhizkar et al[20], 2013	Retrospective cross-sectional study	Iran	34	26.5%	Male and non-smokers. No outcome differences
Navaneethan et al[21], 2013	Retrospective cohort study	United States	50	20%	Elevated serum IgG4 associated with reduced colectomy-free survival in PSC-UC. Shorter time to colectomy from diagnosis of PSC, median time 5 yr (high IgG4) v 12 yr (normal IgG4) P = 0.01
Benito de Valle et al[22], 2014	Retrospective multi-centre (2) cohort study	Sweden and Germany	345	10%	History of pancreatitis combined intrahepatic and extra hepatic biliary involvement, and jaundice. No increased risk of liver transplantation, death or CCA
Taghavi et al[23], 2016	Retrospective cohort study	Iran	73	16%	Higher prevalence of ascites. No clinical outcome differences
Tanaka et al[24], 2017	Questionnaire‐based, multi‐centre, retrospective cohort study	Japan	216	12.5%	Overall mortality and liver transplantation-free survival rate was not different
Muir et al[25], 2018	Phase 2b, dose-ranging, randomized, double-blind, and placebo-controlled study	Northern United States and Europe (61 sites)	234	15%	No difference in fibrosis and progression to cirrhosis in groups stratified by IgG4 level at recruitment

ALP: Alkaline phosphatase; IBD: Inflammatory bowel disease; PSC: Primary sclerosing cholangitis; UC: Ulcerative colitis.