Abstract

Host defense against Mycobacterium tuberculosis (MTB) is essentially a cell mediated immune response. The aim of this study is to assess immune abnormalities in the peripheral blood lymphocyte subsets in patients with pulmonary tuberculosis. Flowcytometry data for peripheral blood lymphocyte subsets in ten patients (mean age of 27 ± 6 years) with pulmonary tuberculosis were compared with similar data from 25 normal healthy individuals (mean age 24 ± 6 years) retrospectively in Immunology Unit at King Khalid University Hospital, Riyadh. The absolute numbers (523.7 ± 360.9 vs 177.1 ± 133.7, p = 0.0000) and % (28 ± 12.8% vs 9.9 ± 5.6%, p = 0.0000) of the natural kller cells and B lymphocytes (426.8 ± 452.1 vs 205.7 ± 69 p = 0.0000 and 18.2 ± 8.1% vs 11 ± 2.5%, p = 0.0000, respectively) were significantly higher in patients with PTB than the normal healthy individuals. A marked reduction in the absolute numbers (542.9 ± 350.3 vs 775.7 ± 225.4, p = 0.0250) and the percentage (30.8 ± 10.7% vs 44.01 ± 5.4%, p = 0.0000) of CD4 + cells in patients with pulmonary tuberculosis was also noted. Elevated natural killer and B cells with CD4 + lymphopenia in pulmonary tuberculosis prompt further investigations to gain a better understanding of host defense against M. tuberculosis.

Key words: Mycobacterium tuberculosis, natural killer cells, lymphocyte subsets, pulmonary tuberculosis.