Serum levels of interferon-γ, interleukin-12, tumour necrosis factor-α, and interleukin-10, and bacterial clearance in patients with gastroenteric Salmonella infection

Cytokines as intercellular signal molecules are responsible to a great extent for the pathological processes in Salmonella infection, as well as for the development of protective mechanisms in the disease. The present study aimed to reveal the correlation between serum levels of IFN-gamma, IL-12, TNF-alpha and IL-10, measured by enzyme-immunoassay, and clearance of bacteria in stool of patients with gastroenteric Salmonella infection. The study included 36 patients with culture confirmed gastroenteric Salmonella infection. At discharge from hospital, 20 patients recovered with bacteriological negative stool culture for Salmonella and 16 were Salmonella excretors. Mean serum concentrations of IFN-gamma, IL-12, TNF-alpha and IL-10 in the acute stage were compared between the 2 groups of patients and with those of healthy controls. Serum levels of examined cytokines were increased (p< 0.001) in the patients in comparison with the healthy controls. In patients with early bacterial clearance mean serum concentrations of IFN-gamma, IL-12 and TNF-alpha in the acute stage were significantly (p< 0.05) higher than in the non-clearance group. IL-10 serum level showed an opposite correlation (p< 0.01) and higher values in Salmonella excretors. The accumulated data imply that Th1 type cytokines probably participate in protective immunity and early bacterial clearance in patients with gastroenteric Salmonella infection.