Lymphocyte Subpopulations in Pulmonary Tuberculosis Patients

Hindawi Publishing Corporation Mediators of Inflammation Volume 2006, Article ID 89070, Pages 1–6 DOI 10.1155/MI/2006/89070 Review Article Lymphocyte Subpopulations in Pulmonary Tuberculosis Patients Figen Deveci,1 H. Handan Akbulut,2 Ilhami Celik,3 M. Hamdi Muz,1 and Fulya İlhan2 1 Department of Chest Diseases, Faculty of Medicine, Firat University, Elazig 23119, Turkey 2 Department of Immunology, Faculty of Medicine, Firat University, Elazig 23119, Turkey 3 Department of Clinical Microbiology and Infectious Diseases, Faculty of Medicine, Firat University, Elazig 23119, Turkey Received 23 December 2005; Revised 9 January 2006; Accepted 20 January 2006 Protection against Mycobacterium tuberculosis is based on cell-mediated immunity, most importantly involving CD4+ and CD8+ T-cell subsets. The aim of this study was to evaluate CD4+ and CD8+ T-cell profiles and CD19+ and CD3− CD(16+56)+ populations in patients with pulmonary tuberculosis. CD4+ and CD8+ T cells, B-lymphocytes, and natural killer (NK) cells were evaluated in 75 active (APTB) and 25 inactive (IPTB) pulmonary tuberculosis cases and 20 healthy subjects (HCs). The results were compared at different stages of antituberculosis treatment in the APTB patients and also according to X-ray findings in the newly diagnosed APTB patients. The percentages of CD4+ T cells were significantly lower (P < .01) and those of CD3− CD(16 + 56)+ cells were significantly higher (P < .01) in APTB patients than in HCs. CD8+ T cells were significantly decreased (P < .05), and CD3− CD(16+ 56)+ cells were significantly increased (P < .01), in IPTB patients compared to HCs. The percentages of CD4+ , CD8+ , CD3− CD19+ , and CD3− CD(16 + 56)+ cells showed no differences at different times of the antituberculosis regimen, and different stages of newly diagnosed APTB patients. APTB patients have a reduced percentage of circulating CD4+ T cells and an increased percentage of NK cells compared with healthy individuals. These cells could play important roles in the immune response to M tuberculosis infection. Copyright © 2006 Figen Deveci et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. INTRODUCTION The host immune response to Mycobacterium tuberculosis, especially cell-mediated immunity, is particularly important in preventing clinically evident disease following infection. CD4+ T cells have an essential role in this response but are supported by other T-cell subsets such as CD8+ [18]. Antigen-presenting cells express the costimulatory molecules necessary for activating T cells. How T cells help them to perform this task remains poorly understood. Primarily, CD4+ T cells are involved in amplifying immune responses by secreting various cytokines, but some CD4+ T cells also serve as cytotoxic effector cells capable of lysing target cells directly [1]. Although decreased CD4+ T cell counts and changes in CD8+ T cell counts are pivotal immune abnormalities in HIV patients, TB may be a cause of non-HIV associated CD4+ lymphopenia [2]. Despite the pivotal importance of CD4+ and CD8+ lymphocytes in antimicrobial immunity, very few researchers have studied changes in the peripheral blood counts of these cells in TB cases, and these few have obtained different results. The aim of this study was to compare the baseline and posttreatment levels of the CD4+ and CD8+ T-cell subsets, and the CD3− CD19+ B-lymphocytes, and CD3− CD(16 + 56)+ NK cell counts, with the radiological extent of the disease in APTB patients and also in IPTB patients. MATERIALS AND METHODS Patients and study design This study was performed on randomly selected 75 APTB patients (age: mean ± SD = 35.76 ± 15.8; 39 women, 36 men) who had been admitted to the Firat Medical Center and Elazig Tuberculosis Dispensary. APTBs were diagnosed on the basis of presence of recent clinical symptoms of tuberculosis, a positive sputum smear test for acid-fast bacilli confirmed by a positive culture of M tuberculosis and characteristics chest radiograph. No extrapulmonary involvement 2 was detected in the patients. The exclusion criteria were HIV positivity, diabetes mellitus, pregnancy, and immunological or autoimmune diseases. Also, APTB patients were divided into three treatment groups as follows [1]. According to antituberculosis treatment (ATT) Group 1. 25 newly diagnosed APTB patients. None of the cases had a priori history of TB or any relevant clinical or radiological findings. Group 2. 25 patients who had undergone 2-month quadruplet antituberculosis treatment (Rifampin, Pyrazinamide, Isoniazid, and Streptomycin or Ethambutol). Group 3. 25 patients who had been treated with antituberculosis drugs for 6 months. In addition, Group 1 patients indicated above were divided into three stages according to the extent and type of X-ray findings as follows [3]. According to the X-ray findings Stage 1 (mild cases, n = 11). Involving a single lobe without visible cavities. Stage 2 (moderate cases, n = 8). Unilateral involvement of two or more lobes with cavities, if present, reaching a total diameter no more than 4 cm. Stage 3 (advanced cases, n = 6). Bilateral disease with massive involvement and multiple cavities. Twenty five inactive (ages 40.23 ± 20.5, 9 women, 16 men) pulmonary TB (IPTB) cases who had been registered and treated in the Elazig Tuberculosis Dispensary were examined, and 20 healthy volunteer subjects (ages 38.20 ± 17.6, 9 women, 11 men) were included as a control group (HC). The IPTB patients had had a previous episode of TB, with positive cultures documented at the time of diagnosis. There were abnormal but stable radiographic findings, and no changes had been observed in previous six months. At least three sputum cultures for M tuberculosis had been negative in all these patients [4]. The healthy subjects had no abnormal X-ray findings or history of TB and no other underlying disease, and they were not currently taking any medication. Smears were pretreated with N-acetylcysteine and 4% sodium hydroxide. The samples were cultured in Lowenstein-Jensen medium and were examined weekly until growth was detected. Cultures were reported as negative if there was no growth after 8 weeks. Cultures with visible growth were processed for biochemical identification of species by standard methods. Tuberculin was identified in the patients by the cutaneous Mantoux test: 5 IU PPD (BB-NCIPD Ltd, Sophia, Bulgaria) was injected intradermally into the volar surface of the forearm. Specifically trained nurses read the PPD reactivity, 72 hours after application, by measuring the transverse axis of Mediators of Inflammation induration (not erythema) with a flexible ruler. The exact number of millimeters was recorded. A transverse induration of ≥ 10 mm was considered a positive response. All APTB and IPTB patients were positive for the (...truncated)