[Cellular immune response in tuberculosis: analysis of T-lymphocytes and their subsets, B-lymphocytes and natural cytotoxic cells in different tuberculosis states and body fluids].

BACKGROUND

The immune response to Mycobacterium tuberculosis is primarily mediated by T lymphocytes. In this study an investigation was made of T lymphocytes and their subsets, B lymphocytes and natural cytotoxic cells (Natural Killer, NK) in blood and organic fluids in different tuberculosis conditions.

METHODS

Patients with localized pulmonary tuberculosis (LPT, n = 12), extensive pulmonary tuberculosis (EPT, n = 24), pleural tuberculosis (PLE, n = 14), disseminated tuberculosis (DIS, n = 10), recent Mantoux converters (MAN, n = 15) and healthy subjects (CON, n = 19) were studied. HIV+ and immunosuppressed patients were excluded. Total lymphocytes and T subsets (CD3, CD4, CD8, TCR alpha beta and gamma delta), B (CD19) and NK cells (CD56) in blood and pleural fluid (n = 7) and ascitic fluid (n = 3) were determined.

RESULTS

An increase was observed in total lymphocytes and all T subsets (CD3, CD4, CD8, alpha beta and gamma delta) in MAN group compared with CON group (p < 0.05 for all determinations). A progressive lymphopenia of total lymphocytes and CD4 was observed with more extensive disease, particularly in the DIS group (p < 0.05). No differences were observed between groups regarding B lymphocytes and NK cells. In pleural effusions and ascitic exudates an accumulation of T lymphocytes, mainly CD4, was observed, with no increase in gamma delta T lymphocytes.

CONCLUSIONS

1) In patients with recent tuberculosis infection T lymphocytosis (total and subsets) occurs. 2) In the absence of HIV infection, a progressive lymphopenia occurs, particularly CD4, with extending disease. 3) In tuberculous pleural effusions and ascitic exudates and accumulation of CD4 T lymphocytes occurs, but not TCR gamma delta lymphocytes.