Interferon-γ and interleukin-17 production from PPD-stimulated PBMCss of patients with pulmonary tuberculosis

The purpose of this study was to evaluate Interferon (IFN)-γ and Interleukin(IL)-17 profiles in patients with different clinical presentations of pulmonary tuberculosis (TB) and to compare them with those of tuberculin-negative and tuberculin-reactive healthy controls

Peripheral blood mononuclear cells (PBMCss), isolated from patients (n=52) and controls (n=30), were stimulated ex vivo with purified protein derivative (PPD) and IFN-γ and IL-17 levels in the supernatant were measured.

At baseline, PBMCss from patients with TB released a significantly lower amount of IL-17 (p=0.043) than PBMCss from healthy controls, whereas IFN-γ levels were similar in the two groups. After PPD stimulation, a significant rise in IL-17 levels was found only among healthy controls (p=0.02). This rise in IL-17 levels was similar between tuberculin-reactive and tuberculin-negative subjects. After PPD stimulation, patients with infiltrative TB secreted higher levels of IL-17 and IFN-γ than those affected with chronic, miliary and cavitary TB (p < 0.01). IFN-γ production from patients with infiltrative TB was even higher than for healthy controls (p < 0.01). PBMCss from tuberculin-reactive patients released higher levels of IFN-γ than tuberculin-negative subjects after PPD stimulation (p < 0.01).

Ex vivo PPD stimulation of PBMCs from patients with pulmonary TB does not significantly stimulate IL-17 release; however, higher IL-17 and IFN-γ levels are found in patients with infiltrative disease, in comparison with those affected with miliary, cavitary and chronic TB.