Cytokines and chemokines are small-secreted proteins involved in many aspects of cell development, differentiation, and activation functions. A prominent characteristic of these molecules is their effect on the immune system in relation to the development of cell trafficking and immune tissues and organs. Furthermore, they play an important role in initiating and coordinating the organized and sequential recruitment and activation of cells into Mycobacterium tuberculosis-infected lungs. We aimed to evaluate the levels of interleukin -17 (IL-17) and the chemotactic chemokine (C-C motif) ligand 5 (CCL5) in the sera of pulmonary tuberculosis (PTB) patients. About 90 subjects were included, involving 50 patients with pulmonary TB and 40 apparently healthy individuals who were selected as a control group. Sera were obtained for measuring IL-17 and CCL-5 levels by enzyme linked immunosorbent assay (ELISA). The results revealed that serum levels of IL-17 showed no significant differences between each patient's group and control. In contrast, the serum level of CCL-5 was significantly increased in pulmonary tuberculosis patients compared to control (P ≤0.01). The mean ±SE values of IL-17 level in PTB patients and controls were 43.06 ±3.64 and 41.009 ± 0.009 pg/ml, respectively. While, the mean ±SE values of CCL-5 level in PTB patients and controls were 455.40 ±25.35 and 80.86 ± 5.96 ng/L, respectively.
The results of the current study suggest that high levels of CCL-5 in the sera of PTB patients may indicate an important role in the immunopathogenesis of the disease. Therefore, this chemokine could be considered as a useful biomarker for the severity of PTB infections.
