CHARACTERIZATION OF LOCAL MEMORY CELLS IN STAGE-CLASSIFIED PULMONARY TUBERCULOSIS - PRELIMINARY-OBSERVATIONS

Immunophenotype analysis and proliferative responses were investigated in bronchoalveolar lavage (BAL) cells from 21 patients with stage-cla ssified tuberculosis: six with localized pulmonary infiltrate (LPI); s even with diffuse pulmonary infiltrate (DPI); and eight with pleural e ffusions (PE). Bronchoalveolar lavage cells from these patients contai ned a high number of cells/ml. The macrophage number was significantly lower in the DPI group (P < 0.05) compared to the LPI or PE groups. C onversely, neutrophils were markedly increased in DPI patients compare d to LPI (P < 0.01) and PE (P < 0.01) patients. Lymphocyte infiltratio n (97.7 +/- 2.3% CD3+, > 83% alpha beta(+) and CD4(+) > CD8(+)) was ob served in the three groups. A significant increase in the number of to tal lymphocytes (P < 0.01) and CD4(+) cells (P < 0.05) was observed in the LPI group compared to the PE group. In the LPI group CD4(+) CD45R O(+) cell infiltration was higher than CD4(+) CD45RA(+) cells (P < 0.0 01), contrasting to similar numbers of these subpopulations in the DPI group. Lymphocytes from three out of three LPI patients (alpha beta() CD4(+) CD45RO(+)) responded against tuberculin purified protein deri vative contrasting to the unresponsiveness of five patients with eithe r DPI or PE. This impaired response was reverted in two out of five pa tients by using peripheral blood monocytes instead of alveolar macroph ages. It is suggested that, in humans, alpha beta CD4(+) CD45RO cells are the main lymphocyte type involved in the initial local cell-mediat ed immune response against Mycobacterium tuberculosis.