Concentrations of CXCL8, CXCL9 and sTNFR1 in plasma of patients with pulmonary tuberculosis undergoing treatment

Background: Chemokines are a class of cytokines with chemotactic properties shown to be induced by M. tuberculosis or its antigens in vitro and in experimental infection in vivo. A few studies have also demonstrated the expression of chemokines in clinical samples of patients with active tuberculosis (TB). In the present work, we measured the concentration of chemokines in plasma samples of HIV-negative patients with pulmonary tuberculosis at different stages of chemotherapy. For comparison, we also evaluated the levels of sTNFR1 and TNF-α. Methods: Cytokines and chemokines were measured by ELISA in healthy individuals and patients with active pulmonary TB at different stages of treatment. Results: The concentrations of CXCL8, CXCL9 and sTNFR1 were elevated in patients with active pulmonary TB but returned to background levels at 4-6 months of chemotherapy. The concentration of CCL11 was elevated in patients with active pulmonary tuberculosis when compared to control and remained elevated throughout the specific therapy. There was no difference in the plasma concentration of CCL2 and CXCL10 between pulmonary TB patients and control subjects. Conclusion: Measurement of the CXCL8, CXCL9 and sTNFR1 may be useful to assess response to treatment in pulmonary TB patients.