Ankylosing spondylitis: acute/subacute vs. chronic iridocyclitis - a bidirectional two-sample Mendelian randomization...

Area of Science:

• Genetics
• Ophthalmology
• Rheumatology

Background:

• Observational studies suggest a link between ankylosing spondylitis (AS) and iridocyclitis (IC).
• The causal relationship between AS and IC has remained unconfirmed.
• Investigating this link is crucial for understanding disease pathogenesis and patient management.

Purpose of the Study:

• To investigate the bidirectional causal relationships between AS and IC using Mendelian randomization.
• To determine if genetic predisposition to AS influences the risk of developing IC.
• To explore potential causal links between subtypes of IC and AS.

Main Methods:

• Two-sample Mendelian randomization (MR) analysis was performed.
• Genome-wide association study (GWAS) data from the FinnGen database were utilized.
• Sensitivity analyses were conducted to assess pleiotropy and heterogeneity.

Main Results:

• Elevated genetic risk for AS showed a positive causal effect on IC and its subtypes.
• A significant causal association was found between Acute/Subacute IC and AS.
• Sensitivity analyses indicated that horizontal pleiotropy was unlikely to bias the findings.

Conclusions:

• This study provides robust evidence for a positive causal relationship between AS and IC in the European population.
• Acute/Subacute IC, specifically, is associated with an elevated risk of AS.
• These findings underscore the importance of considering AS in the clinical evaluation of Acute/Subacute IC.