Periodontitis and Sjogren's syndrome: a bidirectional two-sample mendelian randomization study.

Area of Science:

• Genetics
• Epidemiology
• Immunology

Background:

• Observational studies suggest a controversial link between periodontitis (PD) and Sjogren's syndrome (SS).
• Limitations of observational studies necessitate robust causal inference methods.
• Understanding the bidirectional relationship is crucial for clinical management.

Purpose of the Study:

• To investigate the potential bidirectional causal relationship between periodontitis and Sjogren's syndrome.
• To utilize Mendelian randomization (MR) to overcome confounding factors in observational data.
• To assess genetic causality between PD and SS.

Main Methods:

• A two-sample Mendelian randomization (MR) analysis was performed.
• Genome-wide association study (GWAS) data from European ancestry for PD and SS were used.
• Inverse-variance weighted (IVW) method and complementary analyses (CAUSE, weighted median, MR-Egger, MR-PRESSO) were employed.

Main Results:

• No significant causal effect of periodontitis on Sjogren's syndrome was detected (IVW OR=0.939, P=0.8304).
• No significant causal effect of Sjogren's syndrome on periodontitis was found (IVW OR=1.007, P=0.6440).
• Complementary MR methods and pleiotropy tests confirmed the null association.

Conclusions:

• The study found no genetic evidence supporting a causal relationship between periodontitis and Sjogren's syndrome in either direction.
• Results indicate that observed associations in observational studies may not reflect direct causality.
• Further research and cautious clinical interpretation are warranted regarding the periodontal status in Sjogren's syndrome.