c/d T lymphocytes in Mycobacterium tuberculosis infection

Most T lymphocyte receptors consist of alpha and beta chains, and about 10% of the Background – Data on the percentage of c/d T lymphocytes in the peripheral blood peripheral blood T lymphocytes possess receptors containing gamma and delta chains. of patients infected with Mycobacterium tuberculosis are few and contradictory. The exact role of this population of T lymphocytes is not yet clear. There have been The percentage of c/d T lymphocytes in the peripheral blood of tuberculin positive and reports of an increased percentage of c/d T lymphocytes in the peripheral blood of patients tuberculin negative patients with Mycobacterium tuberculosis infection and with M tuberculosis infection, 5 though others have found no difference between patients and healthy controls was compared. Methods – Thirty six patients infected with healthy controls. The aim of this study was to measure the Mycobacterium tuberculosis and 11 healthy controls were studied. Lympercentage of c/d T lymphocytes in the peripheral blood of patients with tuberculosis who phocytes were separated, cytocentrifuged onto glass microscope slides, and reacted had a positive or negative tuberculin reaction. with anti-c/d monoclonal antibody. The percentage of c/d positive cells was determined by microscopic counting of 300 Methods lymphocytes. Thirty six patients (23 men) of mean age 46.6 Results – No difference was found in the years (range 20–74) infected with M tuberculosis percentage of c/d T lymphocytes between were included in the study. Twenty four had a patients and controls. However, when the positive sputum culture for M tuberculosis, 10 patients were divided into two groups acof whom were also sputum smear positive. cording to reactivity or non-reactivity in Patients with negative sputum culture were the Mantoux skin reaction a higher peridentified by the typical chest radiographic feacentage of c/d T lymphocytes was found tures and the course of the disease during in the peripheral blood of patients with antituberculous therapy. Tuberculin testing tuberculin anergy than in tuberculin poswas performed according to the original Manitive patients or controls. toux test – that is, 5 TU PPD (Human Rt, Conclusions – Higher c/d T cell counts are Gödöllö, Hungary) were given intradermally found in tuberculin negative patients with in the forearm and the results were evaluated tuberculosis than in tuberculin positive 72 hours later. The skin test was considered patients or tuberculin positive controls. positive if there was an induration of 10 mm The high c/d T cell counts in tuberculin or more and negative if there was no reaction. anergic patients may reflect a shift in the Positive reactions of more than 10 mm in diaimmune response in a Th2 direction charmeter were seen in 19 cases (more than 15 mm acterised by increased antibody proin six cases) and 17 patients had no tuberculin duction and decreased cell mediated skin reaction at all. Eleven nurses who had responses. worked in our department for longer than six (Thorax 1997;52:375–377) months (10 women) of mean age 34.2 years (range 19–49) acted as healthy controls. Each