Exploring the genetic association between immune cells and susceptibility to osteonecrosis using large-scale population data.

Objectives: Research shows a close association between aberrant immune reactions in osteonecrotic tissues and immune cell infiltration. However, due to limitations in sample size and dataset comprehensiveness, the causal relationship between them is not fully established. This study aims to determine whether there is a causal relationship using a larger and more diverse dataset.

Methods: We conducted a comprehensive Mendelian Randomization (MR) analysis to investigate the causal relationship between immune cell characteristics and osteonecrosis. Utilizing publicly available genetic data, we explored the causal relationships between 731 immune cell features and 604 cases from the FinnGen Finnish database, as well as 257 cases from the UK Biobank database with osteonecrosis data. The inverse-variance weighted (IVW) method was used for the primary analysis, and we employed sensitivity analyses to assess the robustness of the main results. In addition, considering data from the two databases used in this study, a meta-analysis was conducted on the significant immune cells associated with osteonecrosis (FDR <0.05).

Results: our findings suggested that specific immune cell signatures, such as CD20 % lymphocytes, CD62L-monocytes, and CD33br HLA DR CD14cells were associated with increased odds of osteonecrosis. In contrast, EM CD4 activated cells and DP (CD4 CD8) T cells were associated with decreased odds. Notably, osteonecrosis was associated with a potential decrease in CD45 on immature MDSC cell content.

Conclusion: From a genetic perspective, we demonstrated a close association between immune cells and osteonecrosis. These findings significantly enhance our understanding of the interplay between immune cell infiltration and the risk of osteonecrosis, contributing to the potential design of therapeutic strategies from an immunological standpoint.