Zahran Wafaa A, Ghonaim Mabrouk M, Koura Bothina A, El-Banna Hassan, Ali Sahar M, El-Sheikh Nabila
Microbiology & Immunology department, Faculty of Medicine, Menofiya University, Egypt.
Egypt J Immunol. 2006;13(1):67-78.
One third of the world's population is infected with Mycobacterium tuberculosis (MTB). However, active disease can develop only in a small percentage, when the immunity is weakened. The acquired immune response to MTB is primarily mediated by T cells. Natural killer (NK) cells play a central role in innate immunity to microbial pathogens. Human NKT cells have characteristics of both T and NK cells and also exhibit antimycobacterial activity. This work aimed to enumerate T, NK and NKT cells in active pulmonary TB compared with healthy controls and to study the correlation between these cells with different factors affecting prognosis of pulmonary TB as disease severity, complications or associated diseases, antitubrculosis chemotherapy, and age & gender. Of the 22 active tuberculosis patients examined, 17 were recent cases and 5 recurrent. Healthy controls were divided into 14 individuals with detectable reaction to purified protein derivative (PPD+) and 14 individuals without detectable reaction to PPD-. The percentages of T, NK and NKT cells in erythrocyte-lysed whole blood samples were determined using flowcytometry. The percentage of NKT cells was significantly higher among the recently diagnosed MTB cases as compared with both PPD+ (P < 0.01) and PPD- (P < 0.01) healthy controls, while no significant difference could be found in the percentages of T or NK cells among these groups. However, comparing recurrent cases with recently diagnosed cases showed a significant difference only in the percentage of T cells (P < 0.01). There was also a significant difference in the percentage of T cells according to severity of disease (P < 0.01) and in the association of diabetes mellitus (P < 0.01). Age, gender and treatment with antituberculosis chemotherapy had no effect on the percentages of T, NK or NKT cells. It is concluded that T and NKT cells play an important role in immunity against TB. In active pulmonary tuberculosis, increased T cell count points to severity of the disease, while their reduced count predicts bad prognosis. Human NKT cell count is a marker of disease activity. Enumeration of these cells in peripheral blood can be used as a non-invasive prognostic indicator for patients with active pulmonary TB.
世界三分之一的人口感染了结核分枝杆菌（MTB）。然而，只有在免疫力减弱时，一小部分人会发展为活动性疾病。机体对MTB的获得性免疫反应主要由T细胞介导。自然杀伤（NK）细胞在针对微生物病原体的固有免疫中起核心作用。人类NKT细胞兼具T细胞和NK细胞的特性，也表现出抗分枝杆菌活性。本研究旨在对比活动性肺结核患者与健康对照者的T细胞、NK细胞和NKT细胞数量，并研究这些细胞与影响肺结核预后的不同因素之间的相关性，这些因素包括疾病严重程度、并发症或合并症、抗结核化疗以及年龄和性别。在接受检查的22例活动性肺结核患者中，17例为新发病例，5例为复发病例。健康对照者分为14例对纯化蛋白衍生物有可检测反应者（PPD+）和14例对PPD无可检测反应者（PPD-）。采用流式细胞术测定红细胞裂解全血样本中T细胞、NK细胞和NKT细胞的百分比。与PPD+（P<0.01）和PPD-（P<0.01）健康对照者相比，新诊断的MTB病例中NKT细胞百分比显著更高，而这些组中T细胞或NK细胞百分比无显著差异。然而，复发病例与新诊断病例相比，仅T细胞百分比有显著差异（P<0.01）。根据疾病严重程度（P<0.01）和糖尿病合并情况（P<0.01），T细胞百分比也存在显著差异。年龄、性别和抗结核化疗对T细胞、NK细胞或NKT细胞百分比无影响。结论是，T细胞和NKT细胞在抗结核免疫中起重要作用。在活动性肺结核中，T细胞计数增加表明疾病严重程度，而计数减少预示预后不良。人类NKT细胞计数是疾病活动的标志物。外周血中这些细胞的计数可作为活动性肺结核患者的非侵入性预后指标。
