Serum levels of inflammatory cytokines and chemokines were measured in 132 patients with chronic idiopathic neutropenia of adults (CINA) and 34 healthy volunteers (controls) using commercially available micro-ELISA determination kits. We found that serum interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), transforming growth factor-beta(1) (TGF-beta(1)), and soluble tumor necrosis factor receptor p55 (sTNF-RI) were all significantly increased in CINA patients compared to controls. Individual cytokine values inversely correlated with the number of circulating neutrophils. Serum levels of interleukin-8 (IL-8) and RANTES, two potent chemokines for neutrophils and lymphocytes, respectively, were also significantly increased in the group of patients and they inversely correlated with the number of circulating neutrophils. Contrarily, serum levels of interleukin-4 (IL-4), interferon-gamma (IFN-gamma), soluble CD23 (sCD23), and soluble interleukin-2 receptor (sIL-2R) did not show any significant change in the patients studied. We assume that CINA patients have increased serum concentrations of inflammatory cytokines and chemokines mainly produced by activated macrophages, while they disclose normal levels of inflammatory molecules mainly released from activated lymphocytes. These findings provide further evidence for an underlying low-grade chronic inflammatory process in CINA patients, as we previously have suggested. If this chronic inflammation is really the cause of the disorder or it simply represents the result of neutropenia remains to be elucidated.
Copyright 2000 Wiley-Liss, Inc.