[A comparison of lymphocyte populations of the blood and bronchoalveolar lavage in AIDS patients].

Changes in cell immunity made manifest by decreases in blood levels of CD4 T cells is the main indicator of progressing HIV infection. The decrease in these lymphocytes, as well as in the CD4/CD8 index and increases in suppressant or cytotoxic CD8 cells can be detected in bronchoalveolar (BAL) lung samples. It is not clear whether the high incidence of respiratory system diseases in HIV patients stems from local or systemic immune changes. The aim of this study was to compare changes in the systemic cell immunity studied in samples of peripheral blood with changes detected in BAL samples from HIV patients with acute respiratory disease. We studied 42 patients in the advanced stages of AIDS (C3 by Centers for Disease Control classification) who were hospitalized for acute respiratory disease and who underwent diagnostic fiberoptic bronchoscopy and BAL. Cell counts and lymphocyte populations were analyzed by flow cytometry in samples of peripheral blood and BAL. The percentage of CD4 lymphocytes and the CD4/CD8 index were lower in BAL, particularly in patients with blood CD4 levels below 12% of the total T cell population, or at a level of 20 CD4 cells/microliters. Changes in cell immunity in patients with advanced HIV infection (C3 classification) and acute respiratory disease are more manifest locally in the lung than peripherally in blood. Lung depletion of CD4 T cells in the lung can be predicted based on blood levels.