In vivo modulation of cytokine synthesis by intravenous immunoglobulin

Abstract

Abstract We examined the effects of intravenous immunoglobulin (IVIG) on cytokine regulation in vivo using samples taken before and after replacement-dose (200–400 mg/kg) IVIG in a group of patients with common variable immunodeficiency (CVID) and X-linked agammaglobulinaemia (XLA). The intracellular cytokine content of CD4+ and CD8+ lymphocytes, and their CD28+/− subsets, were measured following in vitro activation with phorbol myristate acetate (PMA) and ionomycin. The cytokines IL-2, interferon-gamma (IFN-γ) and tumour necrosis factor-alpha (TNF-α), and the early activation marker CD69, were assessed by four-colour flow cytometry of whole blood cultures taken before and after IVIG infusion. There was a significant increase in IL-2 expression in CD4+ (and CD4+28−) cells and an increase in TNF-α expression in CD8+28− cells following IVIG in CVID, but not in XLA patients. IFN-γ and CD69 expression were not affected by IVIG infusion. This increase in TNF-α and IL-2, combined with unchanged IFN-γ expression, is evidence against the putative ‘anti-inflammatory’ role of IVIG, and may explain the failure of resolution of granulomata in CVID patients treated with IVIG alone.