Serum Soluble Cytotoxic T-Lymphocyte-Associated Antigen 4 in Children and Adolescents with Autoimmune Cytopenia

Abstract

utoimmune cytopenias are characterized by the production of autoantibodies against differentiated hematopoietic cells because of defects in central and/or peripheral tolerance. It includes autoimmune hemolytic anemia (AIHA), immune thrombocytopenic purpura (ITP), autoimmune proliferative syndrome (ALPS) and Evans syndrome (EV). Cytotoxic T lymphocyte associated antigen-4 (CTLA-4) is a costimulatory receptor that has a potent inhibitory signal on antigen-activated immune responses and was detected in many autoimmune disorders. A native soluble form of CTLA-4 (sCTLA-4) has been found to interfere with normal immune response leading to auto-reactivity. It was observed in high levels in different autoimmune diseases such as systemic lupus erythematosus, autoimmune thyroid disease, celiac disease and systemic sclerosis. The association between levels of sCTLA-4 and autoimmune cytopenias of children and adolescents patients such as AIHA, ITP, ALPS and ES has not investigated through literature. The aims of our study were to compare levels of soluble CTLA-4 in different types of immune cytopenias and their control in children and adolescent patients and to determine the possible relation between sCTLA-4 and the disease severity and response to treatment in this group of patients.