Genetically predicted inflammatory cytokine levels and risk of retinitis pigmentosa.

PurposeMethodsResultsConclusionThis study aims to estimate the potential causal relationship between genetically predicted levels of inflammatory cytokine and retinitis pigmentosa (RP) by performing Mendelian randomization (MR).Single nucleotide polymorphisms (SNPs) were identified as instrumental variables (IVs) from publicly available genome-wide association study datasets. Inverse-variance weighted (IVW), MR-Egger, weighted median, simple mode, and weighted mode methods were applied in this MR analysis. IVW and MR-Egger were used to confirm heterogeneity and pleiotropy of identified IVs. Leave-one-SNP-out analysis was used to identify SNPs with potential impact.IVW results revealed that elevated levels of Tumor Necrosis Factor Alpha (TNF-α), Macrophage Inflammatory Protein-1a (MIP1a), and Monokine Induced by Gamma Interferon (MIG) were associated with higher RP risk (OR = 2.358, <italic>p</italic> = 0.050; OR = 2.583, <italic>p</italic> = 0.013; OR = 1.851, <italic>p</italic> = 0.015), while elevated levels of Interleukin-16 (IL-16) were associated with reduced RP risk (OR = 0.723, <italic>p</italic> = 0.019). The results of heterogeneity and pleiotropy (<italic>p</italic> > 0.05) confirmed there was no pleiotropy and heterogeneity in our IVW analysis. The association of TNF-α, MIP1a, MIG and IL-16 with RP from sensitivity analyses using these two sets of restricted IVs remained stable.Our study provides evidence of potential causal relationships between several circulating cytokine levels and RP. Elevated levels of TNF-α, MIP1a, and MIG are associated with a higher risk of RP, while elevated levels of IL-16 are associated with a lower risk of RP. These cytokines may be novel biomarkers and therapeutic targets for RP. [ABSTRACT FROM AUTHOR]