Circulating complement factor H levels are associated with disease severity and relapse in autoimmune hepatitis

Area of Science:

• Immunology
• Complement System Biology
• Hepatology

Background:

• The complement system is crucial for innate immunity, with Mannose-binding lectin-associated serine protease (MASP)-2 activating the lectin pathway and complement factor H regulating the alternative pathway.
• The clinical significance of circulating MASP-2 and factor H in autoimmune hepatitis (AIH) remains largely unelucidated.

Purpose of the Study:

• To investigate the association between circulating levels of MASP-2 and factor H and the clinical manifestations of AIH.
• To explore the potential of these complement factors as biomarkers for disease severity and relapse in AIH patients.

Main Methods:

• Serum samples from 63 AIH patients were analyzed for levels of MASP-2, factor H, and C3a.
• Statistical analyses, including multivariate logistic and Cox proportional hazards models, were employed to correlate complement factor levels with clinical features and relapse incidence.

Main Results:

• Patients with AIH exhibited elevated circulating C3a levels compared to controls.
• Decreased serum levels of MASP-2 and factor H were observed, correlating with AIH severity.
• Low factor H levels were significantly associated with severe AIH (OR 0.36, p=0.018) and a higher incidence of relapse (HR 5.19, p=0.041).
• Patients with low factor H showed significantly higher relapse rates (log-rank, p=0.006).

Conclusions:

• Circulating factor H levels are linked to disease severity and relapse incidence in AIH.
• These findings suggest a role for the complement system in the pathophysiology of AIH and highlight factor H as a potential biomarker.