Interleukin-18 gene polymorphisms and rheumatoid arthritis: a meta-analysis

Area of Science:

• Immunogenetics
• Rheumatology

Background:

• Interleukin-18 (IL-18) plays a role in immune responses and is implicated in rheumatoid arthritis (RA) pathogenesis.
• Elevated IL-18 levels in RA patients correlate with disease activity.
• Previous studies on IL-18 gene polymorphisms and RA susceptibility yielded conflicting results.

Purpose of the Study:

• To conduct a meta-analysis to clarify the association between IL-18 gene polymorphisms and RA susceptibility.
• To investigate specific single nucleotide polymorphisms (SNPs): rs1946518, rs187238, and rs360722.

Main Methods:

• A meta-analysis was performed on published studies reporting IL-18 gene polymorphisms and RA.
• Data from 2944 RA patients and 2377 controls for rs1946518 (7 studies).
• Data from 1319 RA patients and 1211 controls for rs187238 (5 studies).
• Data from 1873 RA patients and 1092 controls for rs360722 (2 studies).

Main Results:

• No significant association was found between IL-18 SNPs rs1946518 and rs187238 and RA susceptibility across all populations.
• Subgroup analysis by ethnicity also showed no significant association for rs1946518 and rs187238.
• A significantly lower frequency of the T allele at IL-18 rs360722 was observed in RA patients compared to controls, though based on limited studies.

Conclusions:

• The IL-18 gene polymorphisms rs1946518 and rs187238 are not associated with RA susceptibility.
• The IL-18 rs360722 SNP may be associated with RA susceptibility, but requires confirmation.
• Larger, well-designed studies are needed to definitively establish the role of IL-18 rs360722 in RA pathogenesis.