To assess the CD23 status in patients with juvenile chronic arthritis (JCA), as defined by serum soluble CD23 (sCD23) and the expression of CD23 on peripheral blood mononuclear cells.
Serum sCD23 levels were measured by ELISA in 22 patients with systemic JCA (s-JCA), in 40 patients with antinuclear antibody positive pauciarticular JCA (ANA+ p-JCA), and in 38 healthy controls. CD23 expression on T cells, B cells, and monocytes was determined by flow cytometry analysis of double fluorescence staining.
Serum sCD23 levels were increased in both ANA+ p-JCA and s-JCA; no relation with disease activity or severity was found. In patients with ANA+ p-JCA, serum sCD23 levels were correlated with an increased percentage of B cells expressing CD23, while in patients with s-JCA the serum sCD23 levels were correlated with an increased percentage of monocytes expressing CD23.
Serum sCD23 levels are elevated both in systemic and ANA+ pauciarticular JCA: different cell subset CD23 expression in s-JCA and ANA+ p-JCA (i.e. monocyte or B cell, respectively) suggests that in pauciarticular JCA CD23 may be implicated in B cell activation and autoantibody production, while in systemic JCA may be involved in monocyte activation and in the release of inflammatory mediators.