Causal relationships between circulating inflammatory cytokines and diffuse large B cell lymphoma: a bidirectional Mendelian randomization study.

Diffuse large B cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. Studies indicated that inflammatory cytokines involved in the occurrence and progression of DLBCL and it is challenging to discern causality from the effects due to the presence of feedback loops. We conducted a bidirectional Mendelian randomization (MR) study to investigate the potential causal relationship between DLBCL and inflammatory cytokines. The genetic variants associated with inflammatory cytokines were obtained from a genome-wide association study (GWAS) involving 8293 European participants, and the data on 1010 individuals with DLBCL were sourced from the FinnGen consortium. The primary method employed in this study was the inverse-variance weighted (IVW) method, with supplementary analyses conducted using the MR-Egger, weighted median, and MR-PRESSO approaches. Based on the IVW method, genetically predicted that increasing level of Monokine induced by interferon gamma (MIG/CXC chemokine ligand 9, CXCL9) [OR: 1.31; 95% CI: 1.05-1.62; P = 0.01] and interferon gamma-induced protein 10(IP-10/CXC chemokine ligand 10, CXCL10) [OR: 1.30; 95% CI: 1.02-1.66; P = 0.03] showed suggestive associations with DLBCL risk. DLBCL may increase the level of macrophage colony-stimulating factor (M-CSF) [OR: 1.12; 95% CI: 1.01-1.2; P = 0.03], tumor necrosis factor beta (TNF-β) [OR: 1.16; 95% CI: 1.02-1.31; P = 0.02] and TNF-related apoptosis-inducing ligand (TRAIL) [OR: 1.07; 95% CI: 1.01-1.13; P = 0.02]. This study presents evidence supporting a causal relationship between inflammation cytokines and DLBCL. Specifically, MIG/CXCL9 and IP-10/CXCL10 were identified as indicators of upstream causes of DLBCL; while, DLBCL itself was found to elevate the levels of M-CSF, TNF-β, and TRAIL. These findings suggest that targeting specific inflammatory factors through regulation and intervention could serve as a potential approach for the treatment and prevention of DLBCL.