Unexpected Discovery: Based on Data Mining, Rheumatoid Arthritis Surprisingly Reduces the Risk of Developing Hodgkin’s Lymphoma

To investigate the potential correlation between rheumatoid arthritis (RA) and the predisposition to Hodgkin’s lymphoma (HL), we conducted a comprehensive analysis leveraging Mendelian randomization (MR) techniques and genome-wide association studies (GWAS) data. The study focused on the European population, utilizing comprehensive genome sequences from individuals with RA and malignant lymphoma. To identify single nucleotide polymorphisms (SNPs) strongly associated with RA in the European cohort, we employed the inverse variance weighted (IVW) analysis as a robust genetic tool. Furthermore, we utilized various analytical methods, including IVW, weighted median analysis, weighted mode, and MR-Egger regression, to delve into the potential association between RA and the risk of malignant lymphoma in this population. Our findings, obtained through rigorous statistical analysis, revealed a significant causal relationship. Specifically, the IVW analysis (OR = 0.789, 95% CI: 0.6588–0.946, P = 0.009), weighted median analysis (OR = 0.725, 95% CI: 0.607–0.864, P = 0.0001), and weighted mode analysis (OR = 0.709, 95% CI: 0.600–0.838, P = 0.002) consistently indicated that RA decreases the risk of developing malignant lymphoma. Importantly, our results did not indicate any evidence of horizontal pleiotropy (Egger intercept = 0.04, P = 0.576) or heterogeneity (P = 0.056), suggesting the robustness and reliability of our findings. Further sensitivity analysis and statistical evaluations did not yield any notable exceptions or deviations from our initial conclusions. In summary, our study provides compelling evidence that, in the European population, rheumatoid arthritis may serve as a protective factor, reducing the risk of developing Hodgkin’s lymphoma.