Immune profile alterations of systemic lupus erythematosus patients with infections

This study aimed to elucidate the immune status of systemic lupus erythematosus (SLE) patients with infections. We enrolled 253 SLE patients including 77 patients with infections. Clinical features and immunological parameters were analyzed, with particular reference to neutrophil CD64 (nCD64) expression, myeloid-derived suppressor cells (MDSCs), activated T cells and multiple cytokines. Among the 77 SLE patients with infections, 32 patients (41.56%) developed fever and 20 patients (25.97%) developed serositis, which were higher compared to the non-infection group. A considerably higher level of nCD64 was found in the infection group (4.65 vs 1.01, P < 0.001). In addition, the infection group exhibited higher percentages of total MDSCs (6.99 vs 4.30%, P = 0.003), polymorphonuclear MDSCs (PMN-MDSCs) (P = 0.032) and monocytic MDSCs (M-MDSCs) (P = 0.015). T cells were more activated during infections, with an elevated level of IL-2R (P < 0.001). Specifically, higher percentages of CD4⁺CD38⁺ T cells (55.73 vs 50.17%, P = 0.036), CD8⁺HLA-DR⁺ T cells (59.82 vs 47.99%, P < 0.001) and CD8⁺CD38⁺ T cells (68.59 vs 63.90%, P = 0.044) were identified in the infection group. Furthermore, the serum levels of IL-6, IL-8 and IL-10 were elevated in the infection group (all P < 0.001). Higher proportions of neutrophils, CD4⁺ and CD8⁺ T cells, and MDSCs were activated during infections in SLE patients. Additionally, the serum cytokines altered during infections, with noticeably elevated levels of IL-6, IL-8 and IL-10. Infections may lead to the amplification of immune alterations in SLE.