Implication of Increased Serum IL-31 for Primary Biliary Cholangitis

ABSTRACT

Interleukin-31 (IL-31) has diverse biological functions. Increased IL-31 has been found in some skin and autoimmune diseases. There has been no study reporting the association between IL-31 and primary biliary cholangitis (PBC). This study was designed to determine serum IL-31 level and to explore its diagnostic value for PBC as well as the association of IL-31 with inflammatory and fibrotic progression. 60 PBC patients, 32 age- and sex-matched patients with chronic hepatitis B (CHB) and 30 age- and sex-matched healthy controls (HC) were recruited. The sera were detected for IL-31, IL-4, interferon gamma (IFN-γ), IL-17 and other laboratory indicators. Serum IL-31 levels were significantly higher in PBC patients (median, IQR, 20.6, 16.7–26.2, pg/ml) than CHB patients (median, IQR, 11.3, 8.0–13.0, pg/ml) and HC (median, IQR, 11.0, 10.0–12.2 pg/ml) (P < .001). Serum IL-31 performed well for identifying PBC, especially for antimitochondrial antibodies (AMA)-negative PBC with AUC of 0.900, optimal cutoff value of 13.6 pg/ml, sensitivity of 87.5% and specificity of 83.9%. Serum IL-31 was positively correlated with platelet count (r = 0.368, P = .004), but negatively with FIB4 (r = −0.307, P = .017) and histological stages (r = −0.364, P = .004) in PBC patients. It was also significantly correlated with IFN-γ (r = 0.404, P = .001) and IL-4 (r = 0.291, P = .026), but not with IL-17 (r = 0.151, P = .259) in PBC patients. Serum IL-31 is increased in and may be a useful marker for PBC, in particular, for AMA-negative PBC. Furthermore, it is inversely associated with fibrotic progression of PBC.

KEYWORDS:

• Diagnostic performance
• interleukin-31
• primary biliary cholangitis

Disclosure statement

The authors have no conflicts of interest to declare.

Additional information

Funding

This study was supported by four grants from the National Natural Science Foundation of China and Medical Health Science and Technology Project of Zhejiang Provincial Health Commission (81671594, 81571591, 2019309067 and 2020KY1040).