Causal effect of tea consumption on the increased risk of puerperal sepsis and the mediation effect of CD25 on IgD- CD38-B cell: A Mendelian randomization analysis.

Puerperal sepsis is a special type of sepsis characterized by a poor prognosis. The relationship between tea consumption and puerperal sepsis remains controversial. This study aimed to investigate the causal relationship between tea consumption and the risk of puerperal sepsis, as well as to explore the mediating effects of immune traits. In this study, the Mendelian randomization (MR) analysis was used to explore the causal effect of tea intake on postnatal sepsis risk and mediators. Multiple methods were used used for verification. The 2-sample MR analysis showed a positive causal relationship between tea consumption and puerperal sepsis Inverse Variance Weighted (IVW) Inverse Variance Weighted: OR (odds ratio): 1.599 [1.034-2.472], P < .05). The conclusion was confirmed by a meta-analysis of 4 external validation datasets (IVW: OR: 1.303 [1.016-1.678], P < .05). Based on a 2-step MR analysis of 731 immune traits, we found that CD25 on IgD- CD38-B cell positively mediated the effect of tea on puerperal sepsis. Women who drink tea for a long time and in large quantities are potentially at high risk of postpartum sepsis and deserve attention.