High levels of interleukin 6 production from peripheral blood mononuclear cells of children with systemic lupus erythematosus

Objective To investigate the endogeneous overexpression of IL6 gene and abnormal high production of IL6 protein in peripheral blood mononuclear cells (PBMC) of children with active and inactive systemic lupus erythematosus (SLE) Methods The serum IL6 level and freshlyisolated PBMC lysate IL6 content in 18 children with active SLE (1 boy and 17 girls, aged 6.516 years old, average 92 years old) and 12 children with inactive SLE (2 boys and 10 girls, aged 714 years, average 83 years old) were measured by ELIAS, and IL6 gene expression in the PBMC in the same groups of children was measured by in situ hybridization Results The levels of IL6 in sera and PBMC lysates as well as IL6 mRNA expression in PBMC in children with active and inactive SLE were higher than those in the normal group A linear positive relationship was found among them The serum IL6 level, IL6 content and mRNA expression in PBMC in children with inactive SLE were lower than that in children with active SLE The serum IL6 level in positive antidsDNA antibody group was higher compared with that in negative group Conclusion Endogeneous overexpression of IL6 derived from PBMC in children with SLE might be one of the causes that result in elevated level of IL6 in blood, which may be associated with the production of autoantibodies The high level of serum IL6 in SLE may be an indicator of disease activity