ELEVATED CHEMOKINE LEVELS IN BRONCHOALVEOLAR LAVAGE FLUID OF TUBERCULOSIS PATIENTS

In pulmonary tuberculosis, the proportion of lymphocytes, particularly that of CD4(+) T lymphocytes was increased in bronchoalveolar lavage fluid (BALF), reflecting their protective role against mycobacterial i nfections. In order to elucidate the mechanisms of lymphocyte accumula tion in lungs, we measured the levels of chemokines with potent lympho cyte chemotactic activities, including interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and, regulated on activation, norma l T-cell expressed and secreted (RANTES) present in BALF from patients with pulmonary tuberculosis in acute (n = 10) and convalescent phases (n = 6), as well as normal subjects (n = 10). During the acute phase of the disease, the proportions of lymphocytes and neutrophils were in creased, as reported in previous studies. The levels of IL-8, MCP-1, a nd RANTES in the acute phase of pulmonary tuberculosis were also marke dly elevated as compared with those of normal subjects. MCP-1 and RANT ES, but not IL-8 levels present in BALF, decreased in the convalescent phase. Moreover, the concentration of RANTES correlated significantly with the absolute number of CD4(+) cells in BALF. These data suggest that chemotactic cytokines are differentially produced and participate in the host response to Mycobacterium tuberculosis infection.