Causal association between B cell count and psoriasis using two-sample Mendelian randomization

Abstract

To investigate the causality between B cell count and psoriasis by Mendelian randomization (MR). Collected B cell count and psoriasis data from IEU Open GWAS Project. Employed inverse variance weighting (IVW), MR-Egger, WM, weighted mode for analysis, ensuring result robustness. Assessed horizontal pleiotropy with MR-Egger, detected outliers using MR-PRESSO and examined instrumental variables heterogeneity with Cochran's Q-test. The IVW method suggested an association between a genetically predicted memory B cell count and the risk of psoriasis vulgaris. IVW results also showed no causality between other exposure factors and the corresponding outcomes. Also, the global test of MR-PRESSO analysis showed a significant association between a genetically predicted transitional absolute B cell count and the lower risk of psoriasis vulgaris. MR-Egger regression showed that horizontal pleiotropy did not influence the analysis results. We found that memory B cell absolute counts are associated with a lower risk of psoriasis. These data further elucidate the role of memory B cells in psoriasis and provide new options for psoriasis treatment.

Keywords: B cell count; Mendelian randomization; psoriasis.

FIGURE 1

Overview of Mendelian randomization. Single nucleotide polymorphisms (SNPs); inverse‐variance weighted (IVW); weighted median (WM); leave‐one‐out (LOO).

FIGURE 2

A causal association between memory B cell absolute count and the risk of psoriasis vulgaris. Forest plot image (A); leave‐one‐out plot (B); funnel plot image (C); scatter plot image (D). (a) Memory B cell absolute count versus ‘non‐cancer illness code self‐reported: Psoriasis’; (b) memory B cell absolute count versus ‘Psoriasis (vulgaris), strict definition’.