Management, outcomes and survival of an Australian IgG4-sclerosing cholangitis cohort: The MOSAIC study. [Hepatology]

Abstract

Background: IgG4-Sclerosing Cholangitis (IgG4-SC) is an uncommon clinical entity that has an uncertain prognosis and incompletely defined clinical management pathway. Existing data are predominantly from Japanese populations with limited data from Western countries. We sought to describe the presentation, management and outcomes of an Australian IgG4-SC population Methods: Retrospective data collection from major liver centres affiliated with the ALA Clinical Research Network with site selection based on an affirmative response to an expression of interest Patients were included as IgG4-SC if they fulfilled the criteria for definite or probable IgG4-SC according to the IgG4-SC 2012 clinical diagnostic criteria Baseline demographic and biochemical data were obtained in addition to treatment response Follow-up data included disease progression, relapse, development of malignancy and survival Results: 53 patients from 18 institutions met the inclusion criteria (M/F 40/13; Age 64 2+/-1 9 year [range 14.5 - 84.1 years]). Caucasian (68%) and Asian (28%) A previous diagnosis of PSC had been made in 3 (6%) subjects and a suspected biliary tract malignancy or pancreatic tumour in 5 (9%) Three subjects had evidence of cirrhosis The most frequent presenting symptom was jaundice (62%) and abdominal pain (32%) and 34% had co-existing diabetes mellitus Bilirubin (80+/-13mumol/L), ALT (267+/-43 U/L) and IgG4 (6.2+/-0.8 g/L) were significantly elevated at diagnosis and 38% had Ca19-9 > 37 kU/L (range 1-2248 kU/L). The bile duct lesion was: Type 1 (distal bile duct stricture only; 57%), Type 2A (13%), Type 2B (2%), Type 3 (13%) and Type 4 (9%) IgG4-SC was associated with other IgG4-related diseases, most commonly: autoimmune pancreatitis (AIP) (55%), dacryoadenitis/sialadenitis (15%) 87% received prednisolone as initial treatment and 60% achieved remission while a further 19% experienced a partial response with a median time to best response of 3 4 months Endoscopic dilatation was performed in 7 subjects and biliary stenting in 32 (60%) subjects Azathioprine was the most frequent second line agent or steroid-sparing agent (43%) with 6-MP used in 2 subjects and Methotrexate in 1 subject Over a follow up time of 4 5+/-0 5 years, 3 subjects progressed to cirrhosis, 1 patient (2%) developed an HCC, and 2 subjects died (one liver related death, the other unknown) Conclusion(s): This is the first Australian series of IgG4-SC and represents the second largest series of IgG4-SC from a Western country. The most frequent bile duct lesion in IgG4-SC is an isolated distal CBD stricture (Type 1) and IgG4-SC is frequently associated with other IgG4-related diseases Over half of patients achieved a complete response with steroid therapy, however biliary tract intervention is frequent and IgG4-SC can progress to cirrhosis No cholangiocarcinoma were detected and one HCC was diagnosed (in a patient who had progressed to cirrhosis).