CD163 levels, pro- and anti-inflammatory cytokine secretion of monocytes in children with pulmonary tuberculosis

Abstract

Objectives: Childhood tuberculosis (TB) comprises an important part of the world's TB burden. Monocytes set up the early phase of infection because of innate immune responses. Understanding the changes in monocyte subsets during multisystem infectious diseases may be important for the development of novel diagnostic and therapeutic strategies. The aim of this study was to evaluate the monocyte phenotype together with the cytokine secretion profiles of children with pulmonary tuberculosis. Study Design: Thirteen patients with pulmonary TB were enrolled as study group, and 14 healthy subjects as control group. Surface expressions of CD16, CD14, CD62L, CD163, CCR2, and HLA-DR of monocytes were analyzed by flow cytometry. The presence of IFN-gamma, TNF-alpha, IL-10, IL-12, IL-23, and soluble form of CD163 (sCD163) in the antigen-and LPS-stimulated whole blood culture supernatants were detected using ELISA and Luminex. Results: Higher percentages of CD14(++)CD16(+) and CD14(+)CD16(++) monocyte subsets, and CCR2, CD62L and CD163 expression on circulating monocytes in children with pulmonary tuberculosis were obtained. Diminished levels of ESAT-6/CFP-10-induced IL-10 and increased levels of TB-antigen and LPS-stimulated sCD163 were found in childhood with pulmonary TB. Conclusions: High expression of CD14(++)CD16(+), CD14(+)CD16(++), CD14(+)CCR2(+), and CD14(+)CD62L(+) cells in childhood TB, and monocyte-derived cytokines reflected both pro-and anti-inflammatory profiles. Higher sCD163 and CD14(+)CD163(+) monocytes might help physicians in the differential diagnosis of pulmonary TB in children.