Cytokine production by peripheral blood mononuclear cells in IgA nephropathy

Abstract

The regulation of cytokine production and T cell proliferation by other cytokines is mandatory in mediating inflammatory responses but the full understanding is far from complete. We have previously reported increased production of IL-2 and IL-2 receptors (IL-2R) in IgA nephropathy. The present study was undertaken to examine other cytokine production during T cell activation in IgA nephropathy. Peripheral blood mononuclear cells (PBMC) from 17 IgA nephritic patients and 14 controls were cultured with phytohaemagglutinin and phorbol myristate acetate for 48 h for maximal cytokine production. IL-2Rs and IL-4 receptors (IL-4Rs) expressed on cultured PBMC were studied by a radioimmunoassay using monoclonal antibodies against these receptors. Although the total cellular IL-2R expression and percentages of T helper and T suppressor cells did not differ between the patients and controls, there was a significant increase in activated T helper cells expressing IL-2R in patients with IgA nephropathy. The total cellular IL-4R expression was elevated in IgA nephritic patients (P < 0.005). IL-2 production by PBMC was raised in IgA nephritic patients compared with controls (P < 0.05) but no difference in IL-4 or IL-6 production was observed. The interferon-gamma production by PBMG was significantly increased in patients with IgA nephropathy (P < 0.025). No correlation was observed between individual cytokine levels. Our data suggest there are selective increases in cytokine production in IgA nephropathy.