Implication of Increased Serum IL-31 for Primary Biliary Cholangitis

Area of Science:

• Immunology
• Gastroenterology
• Biochemistry

Background:

• Interleukin-31 (IL-31) is implicated in various autoimmune and skin diseases.
• Elevated IL-31 levels have been observed in several autoimmune conditions.
• No prior studies have investigated the role of IL-31 in primary biliary cholangitis (PBC).

Purpose of the Study:

• To determine serum IL-31 levels in patients with PBC.
• To evaluate the diagnostic potential of serum IL-31 for PBC.
• To explore the association between IL-31 and disease progression, including inflammation and fibrosis.

Main Methods:

• Serum samples were collected from 60 PBC patients, 32 chronic hepatitis B (CHB) patients, and 30 healthy controls (HC).
• Levels of IL-31, IL-4, interferon gamma (IFN-γ), and IL-17 were measured using immunoassay techniques.
• Statistical analyses were performed to compare IL-31 levels and assess correlations with clinical and laboratory parameters.

Main Results:

• Serum IL-31 levels were significantly higher in PBC patients compared to CHB patients and HC (P < .001).
• Serum IL-31 demonstrated good diagnostic performance for PBC (AUC=0.900), particularly for AMA-negative PBC (sensitivity 87.5%, specificity 83.9%).
• IL-31 showed a positive correlation with platelet count and negative correlations with FIB4 index and histological staging in PBC patients, alongside associations with IFN-γ and IL-4.

Conclusions:

• Serum IL-31 is significantly elevated in PBC patients.
• IL-31 may serve as a useful diagnostic biomarker for PBC, especially for the antimitochondrial antibody-negative subset.
• Serum IL-31 levels are inversely associated with the fibrotic progression of PBC.