Peripheral mononuclear cells and systemic lupus erythematosus association: Integrated study of single-cell sequencing and mendelian randomization analysis.

Objective: Systemic Lupus Erythematosus (SLE) is a complex autoimmune disease predominantly affecting women. Despite advances in treatment, recent developments in single-cell RNA sequencing (scRNA-seq) and Mendelian randomization (MR) continue to facilitate the need for precision medicine.

Methods: Data obtained from the GSE135779 dataset underwent quality control, normalization, and dimensionality reduction using Seurat and MonacoImmuneData. Marker genes identified subgroups for analysis with CellChat and ClusterProfilerR. MR analysis of these genes' eQTLs was performed to establish causal relationships with SLE using IEU Open GWAS project data.

Results: Single-cell analysis revealed distinct cellular subtypes and highlighted increased monocyte levels in patients with SLE. MR analysis revealed 12 genes, particularly interferon induced protein with tetratricopeptide repeats 3 (IFIT3), causally related to SLE. Gene ontology and the Kyoto encyclopedia of genes and genomes analyses identified pathways significant to SLE pathogenesis. Visualization of these genes at the single-cell level revealed their role in disease progression. Cell communication differences between IFIT3-positive and -negative groups were also observed.

Conclusion: This study demonstrates the potential of scRNA-seq and MR in identifying critical factors in SLE pathogenesis, thereby supporting the need for targeted therapies. Identifying IFIT3, among other genes, as central to SLE progression opens new avenues for precision medicine approaches in SLE management.