[Research advances in immunological pathogenesis of immunoglobulin A vasculitis].

Immunoglobulin A (IgA) vasculitis is the most common leukocytoclastic small-vessel vasculitis in children and mainly involves the small vessels in the skin, joints, digestive tract, and kidneys. Its pathogenesis is still unclear. Currently, it is believed that environmental factors can cause autoimmune dysfunction and lead to the deposition of IgA-containing immune complexes on the wall of arterioles on the basis of genetic factors. This article reviews the research advances in the role of immune factors in the pathogenesis of IgA vasculitis.

[Effects of dexamethasone on CTLA-4 expression and apoptosis in lymphocytes obtained from children with mesangial proliferative nephritis].

OBJECTIVE: The pathogenesis of mesangial proliferative glomerulonephritis (MsPGN) and mechanisms of glucocorticoid (GC) resistance have not been fully identified. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is an important inhibitor of T-lymphocyte activation. The objective of the study is to investigate the CTLA-4 expression and apoptosis in lymphocytes of children with MsPGN and the effects of dexamethasone (Dex) on the CTLA-4 expression and apoptosis. METHODS: Blood samples were collected from 36 children with MsPGN and 30 healthy children. CTLA-4 expression in in vitro cultured lymphocytes with or without Dex treatment was measured by flow cytometry following direct immune fluorescene. The rate of apoptosis in the lymphocytes was evaluated by annexin V-FITC and propidium iodide staining. RESULTS: The CTLA-4 expression and apoptosis in lymphocytes from children with MsPGN were significantly lower than those in the healthy control children in the absence or presence of Dex treatment (p<0.05). There was a positive correlation between CTLA-4 expression and apoptosis in lymphocytes (p<0.05). CONCLUSIONS: Abnormal CTLA-4 expression may participate in the pathogenesis of MsPGN and be one of mechanisms of GC resistance.