48 Low-dose IL-2 therapy rescues decreased peripheral lymphocytes in SLE patients with different infectious status

Background Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disorder characterized by autoantibody production to a variety of self-antigens. This abnormal immunological background and immune-suppressive therapies predispose SLE patients to infection. Recent studies have revealed that low-dose IL-2 not only regulates immune balance but also alleviates directly SLE disease activity. In this study, we assessed the alterations of lymphocyte subpopulations and the effect of restore the immunologic balances by low dose IL-2 in SLE patients with different infectious status. Methods Total 495 SLE patients were enrolled. Among them, 162 with infection were determined by a positive pathogen test from various specimens or clear evidence of infection. Lymphocyte subpopulations were analyzed by flow cytometry in peripheral blood of these patients as well as 132 age-and sex-matched healthy donors. To investigate effects of low-dose IL-2 on these subsets in infection conditions, 54 patients with (n=13) or without(n=41) infection were received the treatment of IL-2 at 0.5 million IU per day for 5 days subcutaneously. Results Notably, the absolute numbers of lymphocyte subpopulations in peripheral blood such as T, B, NK, CD4 +T, CD8 +T, Th1, Th2, Th17 and Treg cells in infected patients were the lowest among three groups (p Conclusions Patients with SLE, especially those suffering infections, had a disturbance in immune system by decreased number of various lymphocyte subsets. This preliminary finding suggests that low-dose IL-2 combination treatments restored the decreased number of lymphocyte subpopulations, neutrophils and platelets and lowered ESR of these patients. Further studies are needed to evaluate the long-term anti-infection ability of IL-2 treatment. Funding Source(s): None