Mendelian randomization analysis of C-reactive protein on septic arthritis risk.

Several observational studies have shown that C-reactive protein (CRP) is an effective biomarker for evaluating septic arthritis (SA). However, the inherent causal relationship of this connection has not yet been clarified. Thus, this study examined the potential causal association between CRP and SA risk using 2-sample Mendelian randomization (MR). The analysis used 2-sample MR, with the exposure and outcome data from the Genome-Wide Association Study Catalog and FinnGen, respectively. Throughout this study, inverse variance weighting has been used as the primary method. To assess the robustness of the research findings, Cochran Q test, Egger regression, and MR pleiotropy residual sum and outlier global tests were conducted. Genetically predicted CRP has a positive causal relationship with the risk of SA (ORinverse variance weighting = 1.37, 95% CI 1.16-1.63, P < .001), (ORMR Egger = 1.62, 95% CI 1.20-2.19, P = .002), (ORweighted media = 1.48, 95% CI 1.11-1.97, P = .008), and (ORMR PRESSO = 1.37, 95% CI 1.18-1.59, P < .001). A sensitivity analysis confirmed the robustness of this result. Our study has, for the first time, established a definite causal relationship between CRP and SA risk; that is, an increase in CRP levels leads to an increase in SA risk.