Review of primary sclerosing cholangitis with increased IgG4 levels

Table 3 HISORt Criteria for IgG4-related sclerosing cholangitis (Adapted from references[32,44])

Histology (Criterion H)	Lymphoplasmacytic infiltrate with > 10 IgG4+ cells per high‐power field within and around bile ducts; obliterative phlebitis; storiform fibrosis
Imaging (Criterion I)	Strictures of the biliary tree including intrahepatic ducts, proximal extra-hepatic ducts, intra-pancreatic ducts; fleeting and migrating biliary strictures
Serology (Criterion S)	Raised serum IgG4 levels (> 1.35 g/L)
Organ involvement (Criterion O)	Extra-biliary manifestations consistent with IgG4-RD, such as: pancreas (focal pancreatic mass/enlargement without pancreatic duct dilatation, multiple pancreatic masses, focal pancreatic duct stricture without upstream dilatation, pancreatic atrophy); retroperitoneal fibrosis; kidney (single or multiple parenchymal low‐attenuation lesions: Round, wedge‐shaped, or diffuse patchy); salivary or lacrimal gland (enlargement)
Response to treatment (Criterion R)	Normalisation of liver enzymes and at least partial stricture resolution after steroid treatment

Definite IgG4-SC: Patient meets criterion H or Criterion S with Criterion I; Probable IgG4-SC: Patient meets 2 of the following criteria: Criterion S, Criterion O, partially meets criterion H, partially meets criterion I. Patients with probable diagnosis can proceed to trial of corticosteroids. If they then meet criterion R, then the diagnosis becomes definite. IgG4-RD: IgG4-related disease; IgG4-SC: IgG4-related sclerosing cholangitis