Primary biliary cirrhosis and psoriasis: a two-sample Mendelian randomization study

Area of Science:

• Hepatology
• Dermatology
• Genetic Epidemiology

Background:

• Primary biliary cirrhosis (PBC) and psoriasis frequently co-occur.
• The causal relationship and underlying mechanisms between PBC and psoriasis are not well-defined.

Purpose of the Study:

• To investigate the potential bidirectional causal relationship between primary biliary cirrhosis and psoriasis.
• To explore the genetic associations between PBC and psoriasis.

Main Methods:

• Bidirectional Mendelian randomization (MR) analysis was employed.
• Four MR methods (IVW, MR-Egger, weighted median, weighted mode) were utilized.
• Sensitivity analyses, including heterogeneity and pleiotropy testing, confirmed result robustness.

Main Results:

• A significant causal effect of primary biliary cirrhosis on the risk of psoriasis was identified (OR: 1.081, P<0.05).
• No significant causal effect of psoriasis on primary biliary cirrhosis risk was found (OR: 1.022, P>0.05).
• MR-Egger regression indicated no significant genetic pleiotropy, and leave-one-out analysis confirmed the robustness of findings.

Conclusions:

• Primary biliary cirrhosis causally increases the risk of developing psoriasis.
• Psoriasis does not appear to causally influence the risk of primary biliary cirrhosis.
• This study provides novel insights into the etiology of primary biliary cirrhosis and its association with psoriasis.