The Proportion of Lymphocytes and Eosinophils in Leukocytes as Early Screening Markers for Sepsis: a Mendelian Randomization Analysis.

Background: This study aimed to explore the potential role of white blood cell components in the early screening of sepsis using Mendelian randomization. The analysis considers five cell types: lymphocytes, monocytes, neutrophils, eosinophils, and basophils.

Methods: Relevant genome-wide association study (GWAS) datasets were retrieved from the IEU Open GWAS Project. Subsequently, a two-sample Mendelian randomization (MR) analysis was conducted, with the proportions of the five cell types within white blood cells as the exposure factors and the occurrence of sepsis as the outcome variable. Specifically, Cochran's Q statistic was employed to test heterogeneity, and horizontal pleiotropy of instrumental variable SNPs was examined.

Results: The Mendelian randomization analysis indicated that the proportion of lymphocytes may potentially predict the occurrence of sepsis, with a weighted median algorithm yielding an OR (95% CI) of 1.1536 (1.0018 - 1.3284). The proportion of eosinophils may potentially reduce the risk of sepsis, with p-values of 0.0349 and 0.0243 from the IVW and MR-PRESSO algorithms, respectively, and OR (95% CI) values of 0.9273 (0.8645 - 0.9947) and 0.9218 (0.8594 - 0.9888).

Conclusions: An increased proportion of lymphocytes and a decreased proportion of eosinophils in white blood cells may serve as potential biological markers for the early detection of sepsis.