Causal Role of Immune Cells in Inflammatory Bowel Disease: A Mendelian Randomization (MR) Study

The present Mendelian randomization study investigated the potential causal relationship between immunophenotypes and inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC). Results demonstrated that immunophenotypes, such as CD28 on CD39+ resting Treg and CD25 on IgD+ CD24− showed nominal significant protective effects on CD and UC, respectively. Conversely, specific immunophenotypes also exhibited nominal significant risk effects on CD and UC, including CD39 on CD39+ CD8br and IgD on IgD+ CD38dim, respectively. Collectively, our findings highlight the potential role of immune cell phenotypes in the development of CD and UC as evidenced by data analysis from the FinnGen database. Therefore, the present study contributes to understanding the genetic basis of IBD and highlights the significance of immune cell phenotypes in disease pathogenesis.