Molecular Dissection of Disease Heterogeneity in SLE

Systemic lupus erythematosus (SLE) affects 1 in 537 of African American (AA) women, which is >2-fold more than European American (EA) women. AA patients also develop the disease at a younger age, have more severe symptoms, and a greater chance of early mortality. We used a multi-omics approach to uncover ancestry-specific immune alterations in SLE patients and healthy controls that may contribute to disease disparities. Cell composition, signaling, and epigenetics were evaluated by mass cytometry; droplet-based single cell transcriptomics and paired proteogenomics (scRNA-Seq/scCITE-Seq). Soluble mediator levels were measured in plasma and stimulated whole blood. TLR3/4/7/8/9 gene expression pathways in B cells and monocytes were enhanced in AA SLE patients compared to EA patients. TLR7/8/9 and IFN phospho-signaling responses were also heightened in healthy AA versus EA controls. Exposure of AA and EA healthy control cells to TLR7/8/9 agonists or IFN resulted in altered immune cell compositions that recapitulated the ancestry-associated differences in SLE patients. These data support that ancestry-based differences in TLR7/8, TLR9, and IFN responses that can be detected in healthy individuals could influence lupus disease course and severity. multiplexed scRNA-seq with CITEseq profiles of PBMCs from both healthy controls and SLE patients with high and low disease activity. Please note that [1] the SUBnnnnn accessions (in the sample title) are deidentified names for the individual demultiplexed samples [2] The "sample.csv" has sample characteristics for each sample [3] Each processed data file was generated from *cite, *gex, and *hto raw data and is linked to the *cite sample records.