Aims: During brucellosis, infection macrophages and T lymphocytes perform effectively to eliminate microbes. Cytokines are small proteins that have role in activation, differentiation and performance of immune cells. The cytokine secretory pattern can be important in clinical brucellosis outcome. The purpose of this study was to determine the levels of some important cytokines in acute and chronic brucellosis patients during immune response.

Methods: In this case-control study which was performed in Sanandaj’s Tohid Hospital, Iran, 63 patients referred to infectious department were studied. 30 healthy persons were selected as control. 12ml of blood was taken from each patient for performing brucellosis diagnosing tests like serological tests, blood cultures and PCR. Cytokines were measured by using Sandwich-ELISA. Data were analyzed by SPSS 12 software using independent T-test and Mann-Whitney U tests.

Results: The mean serum levels of IL-6, IL-8, IL-10, IFN- g and TGF-β in acute and chronic patients were significantly higher than the control group, but cytokine levels were not significantly different between patients with acute and chronic brucellosis. The serum level of IL-12p70 was not only significantly higher in acute and chronic patients than control group but also was significantly higher in acute than chronic patients.

Conclusion: The inflammatory and non-inflammatory cytokines increases in brucellosis It seems that low levels of IL-12p70 in chronic brucellosis in comparison with acute brucellosis patients is due to a defect in performance of macrophages in chronic patients.