The association of COVID-19 with diffuse large B-cell lymphoma: a Mendelian randomization study.

With the outbreak of coronavirus disease 2019 (COVID-19), there has been an increasing focus on exploring the relationship between SARS-CoV-2 infection and tumors. However, there is no consensus on the association between COVID-19 and lymphoma. In this study, genome-wide association study (GWAS) summary data sets for COVID-19 and lymphoma were obtained from the OPEN GWAS website. Single nucleotide polymorphisms (SNPs) were selected as genetic instrument variants for fulling  < 5 × 10 and linkage disequilibrium [LD] r < 0.001. Both palindromic and outlier SNPs were removed. Cochran's Q test, the MR‒Egger intercept test, and leave-one-out analysis were employed to assess the sensitivity of the effect of COVID-19 on lymphoma. The results showed that COVID-19 patients with very severe respiratory symptoms have an increased risk of developing diffuse large B-cell lymphoma (IVW, OR = 1.765, 95% CI 1.174-2.651,  = 0.006). There was no association between COVID-19 with very severe respiratory symptoms and Hodgkin's lymphoma or other types of non-Hodgkin's lymphoma. No horizontal or directional pleiotropy was observed in the Mendelian randomization analysis. In conclusion, SARS-CoV-2 infection with very severe respiratory symptoms may be a potential risk factor for diffuse large B-cell lymphoma (DLBCL), and follow-up studies with larger samples are needed.