Causal relationship between peripheral immune cell phenotypes and recurrent miscarriage: a two-way Mendelian...

Area of Science:

• Immunology
• Reproductive Health
• Genetics

Background:

• Recurrent miscarriage is a complex condition potentially involving immune system dysregulation.
• Investigating the causal link between immune cell phenotypes and miscarriage risk is crucial for understanding pregnancy loss.

Purpose of the Study:

• To investigate the causal relationship between immune cell phenotypes and the risk of miscarriage using Mendelian randomization (MR).

Main Methods:

• A two-sample MR analysis was conducted using genome-wide association study (GWAS) summary statistics.
• Exposure data on immune cell phenotypes and outcome data on miscarriage risk were sourced from large-scale UK Biobank and MRC-IEU GWAS databases.
• Inverse-variance weighted (IVW) regression, Wald ratio, and MR-Egger methods were employed, with MR-PRESSO used for pleiotropy testing.

Main Results:

• While MR-Egger showed no significant association, IVW and Wald ratio analyses indicated significant links between specific immune cell profiles and miscarriage risk.
• Higher proportions of HLA DR+ CD4+ and CD8+ T cells correlated with increased miscarriage risk.
• Elevated absolute lymphocyte counts, TCRgd T cells, and FSC-A on CD4+ T cells appeared protective, while lower granulocytes and FSC-A on myeloid dendritic cells were linked to higher risk.
• Significant pleiotropy was detected, indicating potential confounding factors.

Conclusions:

• The study suggests a complex interplay between immune cell composition and miscarriage risk.
• These findings offer new insights into the immunological mechanisms underlying pregnancy loss.
• Further research is warranted to confirm associations and identify potential therapeutic targets for immune-related pregnancy complications.