The Yin and Yang of regulatory T cell and therapy progress in autoimmune disease

Autoimmune diseases (ADs) are primarily mediated by the failure of immunological self-tolerance. Regulatory T cells (Tregs) play a critical role in the maintenance of induced tolerance to peripheral self-antigens, suppressing immoderate immune responses deleterious to the host and preventing the AD development. Tregs and suppressive cytokines are homeostatic with effective cells plus pro-inflammatory cytokines in healthy hosts which is defined as "Yang", and ADs are usually induced in case of disturbed homeostasis, which is defined as "Yin". Indeed, the Yin-Yang balance could explain the pathogenic mechanism of ADs. Tregs not only suppress CD4⁺ and CD8⁺ T cells but also can suppress other immune cells such as B cell, natural killer cell, DC and other antigen-presenting cell through cell-cell contact or secreting suppressive cytokines. In Tregs, Foxp3 as an intracellular protein displays a more specific marker than currently used other cell-surface markers (such as CD25, CD40L, CTLA-4, ICOS and GITR) in defining the naturally occurring CD4⁺ Tregs. Though the precise mechanism for the opposite effects of Tregs has not been fully elucidated, the importance of Tregs in ADs has been proved to be associated with kinds of immunocytes. At present, the surface marker, frequency and function of Tregs existed conflicts and hence the Tregs therapy in ADs faces challenges. Though some success has been achieved with Tregs therapy in few ADs both in murine models and humans, more effort should paid to meet the future challenges. This review summarizes the progress and discusses the phenotypic, numeric and functional abnormalities of Tregs and is the first time to systematically review the progress of Tregs therapy in kinds of ADs.

Clinical Features of Systemic Lupus Erythematosus Patients Complicated With Evans Syndrome: A Case-Control, Single Center Study

The aim of the study was to investigate the clinical features of systemic lupus erythematous (SLE) complicated with Evans syndrome (ES). We conducted a retrospective case-control study to compare the clinical and laboratory features of age- and gender-matched lupus patients with and without ES in 1:3 ratios. In 5724 hospitalized SLE patients, we identified 27 (0.47%, 22 women and 5 men, average age 34.2 years) SLE patients complicated with ES. Fifteen patients (55.6%) presented with hematologic abnormalities initially, including 6 (22.2%) cases of isolated ITP, 4 (14.8%) cases of isolated AIHA, and 5 (18.5%) cases of classical ES. The median intervals between hematological presentations the diagnosis of SLE was 36 months (range 0-252). ES developed after the SLE diagnosis in 4 patients (14.8%), and concomitantly with SLE diagnosis in 8 patients (29.6%). Systemic involvements are frequently observed in SLE patients with ES, including fever (55.6%), serositis (51.9%), hair loss (40.7%), lupus nephritis (37%), Raynaud phenomenon (33.3%), neuropsychiatric (33.3%) and pulmonary involvement (25.9%), and photosensitivity (25.9%). The incidence of photosensitivity, hypocomplementemia, elevated serum IgG level, and lupus nephritis in patients with ES or without ES was 25.9% vs 6.2% (P = 0.007), 88.9% vs 67.1% (P = 0.029), 48.1% vs 24.4% (P = 0.021), and 37% vs 64.2% (P = 0.013), respectively. Twenty-five (92.6%) patients achieved improvement following treatment of glucocorticoids and immunosuppressants as well as splenectomy, whereas 6 patients experienced the relapse and 1 patient died from renal failure during the follow-up. ES is a relatively rare complication of SLE. Photosensitivity, hypocomplementemia, and elevated serum IgG level were frequently observed in ES patients, but lupus nephritis was less observed. More than half of patients presented with hematological manifestation at onset, and progress to typical lupus over months to years. Therefore, monitoring with antoantibodies profile as well as nonhematological presentations are necessary for patients with ITP and (or) AIHA.