IgG4-related sclerosing cholangitis (IgG4-SC) alone and IgG4-SC with autoimmune pancreatitis (AIP) share similar clinical features, including several imaging and serology characteristics, according to a study in Digestive and Liver Disease.
The study included a retrospective review of imaging, serology, other organ involvement (OOI), and histology in patients with IgG4-SC who participated in a 2019 nationwide survey in Japan (N=872). Researchers compared the clinical characteristics of survey participants with IgG4-SC alone (n=142) against those with IgG4-SC with AIP (n=730).
A significantly greater proportion of patients in the IgG4-SC with AIP cohort were men (79.9% vs 71.1%; P =.025). Additionally, patients with IgG4-SC and AIP were more likely to have icterus as a symptom (42.9% vs 31.0%; P =.010). In contrast, patients with IgG4-SC without AIP were more likely to have pruritus (20.4% vs 13.6%; P =.039) and fever (7.0% vs 3.2%; P =.049).
No difference was found between patients with IgG4-SC and AIP vs without AIP in regard to bile duct wall thickening observed on ultrasound (82.4% vs 75.7%, respectively; P =.109), computed tomography (69.8% vs 79.1%; P =.076), and magnetic resonance imaging/cholangiopancreatography (65.1% vs 69.5%; P =.519).
An elevated serum IgG4 level ≥135 mg/dL was observed in 88.0% of participants, with no differences found between the 2 groups (88.3% vs 85.7%; P =.616). No difference was found between patients with IgG4-SC and AIP vs without AIP in regard to the rate of IgG4-related OOI (26.4% vs 18.5%, respectively; P =.073). The only significant histopathological finding was that a lower proportion of patients with IgG4-SC with AIP had ≥10 IgG4-positive plasma cells/high power field (HPF) (12.8% vs 29.6%; P <.001) in bile duct biopsy.
Limitations of this study included its retrospective nature, the reliance on questionnaire response data, as well as the potential variability among participating institutions in terms of their diagnostic equipment and methods.
The researchers commented that their study was conducted “to evaluate the clinical characteristics and utility of various items for the diagnosis of IgG4-SC,” suggesting the significant findings could hold future diagnostic implications for differentiating disease with vs without AIP.
Naitoh I, Kamisawa T, Tanaka A, et al. Clinical characteristics of immunoglobulin IgG4-related sclerosing cholangitis: comparison of cases with and without autoimmune pancreatitis in a large cohort. Published online March 1, 2021. Dig Liver Dis. doi:10.1016/j.dld.2021.02.009