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

Abstract Background Autoimmune 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). Aim of the Work to compare levels of sCTLA-4 in different types of immune cytopenias and their control. Patients and Methods Forty seven children and adolescents who have autoimmune cytopenias were recruited and assessed for eligibility in Pediatric Hematology Clinic, Ain Shams University Children’s Hospital and forming a patients group with age range 8 – 204 months old. An age and sex matched healthy control group were recruited including forty seven healthy participants with age range 6 – 156 months old. Results On initial examination in our study, the prevalence of hepatosplenomegaly and lymphadenopathy among the patients group was 27.7% and 2.1% respectively. Autoimmune cytopenic patients group have statistically significant higher serum sCTLA-4 levels (range 1 – 82 ng/ml) than control group (range 0 – 9 ng/ml) (where P < 0.01 HS). On the other hand, there was no significant difference when comparing levels of sCTLA-4 between sera of ITP, AIHA and ALPS patients (P > 0.05). Serum sCTLA-4 was inversely related to the age at diagnosis and positively related to disease duration. Our results demonstrated the presence of correlations between the levels of sCTLA4 and the severity of autoimmune cytopenias (negative correlation with Hemoglobin (R= -0.315; P = 0.031), mean Hemoglobin (last year) (R= -0.471; P = 0.001) and platelet (R= -0.324; P < 0.05)) and (positive correlation between levels of sCTLA-4 and Reticulocyte count (R = 0.413; P = 0.004), Indirect Bilirubin (R = 0.427; P = 0.003) and Lactate dehydrogenase (R = 0.357; P = 0.014)). There was a significant differences in the prevalence of hepatosplenomegaly among ITP, AIHA and ALPS patients (P < 0.05) with higher prevalence among ALPS patients. Conclusion Soluble form of CTLA4 (sCTLA4) presents in elevated levels in the sera of children and adolescents who have autoimmune cytopenia including AIHA/Evans, ITP and ALPS compared to healthy control group that suggests sCTLA4 could play a role in the pathogenesis of immune cytopenias.