Single-cell transcriptomics reveals the alteration of immune cell profile in peripheral blood of Henoch-Schonlein purpura

Henoch-Schönlein purpura (HSP) is an autoimmune vasculitis affecting multiple organs, and the understanding of circulating immune cell types and their states associated with disease subtypes of HSP remains incomplete. Here, we performed a comprehensive assessment of peripheral blood mononuclear cells of healthy donors and HSP patients, using both single-cell RNA sequencing and multiparameter flow cytometry. We revealed that HSP patients exhibited broad immune activation, evidenced by increased proportions of Effector memory CD8+ T, CD14+ monocytes, Tfh, Th2, Th17, Plasma, and B cells and decreased proportions of Naïve CD4+ T, Treg, Th1, and NK cells. Notably, we identified that cytotoxic effector T cell subsets were enriched in skin and renal type of HSP, whereas Plasma, B, and Tfh cells were expanded in joint and abdominal type of HSP. In conclusion, our findings highlight the dynamic nature of immune responses throughout the progression of HSP with different clinical manifestations.