Identification of relapse predictors of IgG₄-related sclerosing cholangitis

Introduction. Relapses occur in 30–50% of patients IgG 4 -related sclerosing cholangitis. Relapses may act an independent risk factor for malignancy development and the need in maintenance therapy for relapse prevention is still uncertain. Thus, studying relapse predictors and developing reliable preventive approaches is an important area of research for this condition. Aim. To determine relapse predictors of IgG 4 -related sclerosing cholangitis. Materials and methods. A single- center dynamic bidirectional observational study was conducted in patients aged 18 years and older with verified IgG 4 -related sclerosing cholangitis (n = 32). We searched for possible factors influencing the relapse of IgG 4 - related sclerosing cholangitis. The development of a prognostic model for the relapse probability was carried out using logistic regression. ROC analysis was used to assess the diagnostic performance of quantitative variables in predicting of relapse. Results. The median follow-up period was 33 (16–60) months. The majority of patients with IgG 4 -related sclerosing cholan- gitis were male (71.9%), median age was 59 ± 13 years. In most patients, delayed diagnosis (median 10.5 [4.8; 22.5] months) was associated with overdiagnosis of primary sclerosing cholangitis (41.2%) or bile duct malignancy (43.8%). Surgical interventions were performed in 50% of patients. Median serum IgG 4 level was 2.70 g/L [1.92; 6.48], and 21.9% of patients had normal serum IgG 4 level. Disease relapse developed in 34.4% (n = 11) of patients. Serum IgG 4 level before glucocorticosteroid therapy ≥ 2.24 g/L and a delay in diagnosis by ≥ 17 months were associated with the relapse (p = 0.040 and p = 0.049 respectively). Multi-organ involvement, and extrahepatic localization of biliary strictures in the patients with the history of surgical interventions increased the risk of relapse 85 (p = 0.001) and 12 (p = 0.047) fold, respectively. The presence of biliary strictures below the confluence reduced the risk of relapse 7.5 fold (p = 0.032). Conclusions. Possible predictors of IgG 4 -related sclerosing cholangitis relapse may include multi- organ involvement, intrahepatic and proximal extrahepatic strictures, prior surgical interventions in patients with extrahepatic strictures, high serum IgG 4 level, and delayed diagnosis.