Comparison of Circulating NKT Cells Numbers in Multi Drug Resistant Tuberculosis Patients and Healthy Subjects Using Tuberculin Skin Test

Natural killer T (NKT) cells are a subset of lymphocytes that express some NK cells properties. NKT cells have a regulatory role in immune responses. Little is known about the potential role of NKT cells in human infectious diseases. The goal of the present study was determination of frequency of Vα24Vβ11 and CD3CD56 NKT cells in tuberculosis patients. According to our criteria, three groups were selected for our study: 30 healthy PPD positive skin test reactors, 30 healthy PPD negative skin test reactors, 30 new case active TB patients and 25 Multi-drug resistance Tuberculosis (MDRTB) patients. Frequency of Vα24Vβ11 and CD3CD56 NKT cells in fresh peripheral blood was determined by Flow cytometry. Frequency of Vα24Vβ11 NKT cells in the new case TB and MDRTB patients as compared to PPD positive healthy donors was significantly decreased (P<0.05), whereas CD3CD56 NKT cell numbers were similar in all groups. According to our results decrease in frequency of Vα24Vβ11 NKT cells may be related to insufficient immune responses to mycobacterium tuberculosis infection, especially in MDRTB patients.