van Brummelen Sigrid E, Bauwens Anja M, Schlösser Noël J, Arend Sandra M
Central Military Hospital, Department of Pulmonology, Utrecht, Netherlands.
Clin Vaccine Immunol. 2010 Jun;17(6):937-43. doi: 10.1128/CVI.00005-10. Epub 2010 Apr 7.
Treatment of latent Mycobacterium tuberculosis infection on the basis of the tuberculin skin test (TST) result is inaccurate due to the false-positive TST results that occur after Mycobacterium bovis BCG vaccination or exposure to nontuberculous mycobacteria (NTM). Gamma interferon release assays (IGRAs) are based on M. tuberculosis-specific antigens. In a previous study among BCG-naïve military employees, a positive TST result after deployment was mostly associated with a negative IGRA result, suggesting exposure to NTM. Data regarding the kinetics of IGRAs are limited and controversial. The present study aimed to reassess the rate of false-positive TST results and to evaluate the kinetics of the Quantiferon TB Gold In-Tube assay (QFT-Git) in military personnel with a positive TST result. QFT-Git was performed at the time of inclusion in the study and was repeated after 2, 6, 12, and 18 or 24 months. Of 192 participants, 17 were recruits and 175 were screened after deployment (n = 169) or because of travel or health care work. Baseline positive QFT-Git results were observed in 7/17 (41.2%) and 12/174 (6.9%) participants, respectively. During follow-up, a negative QFT-Git result remained negative in 163/165 (98.8%) participants. Of 18 subjects with an initial positive QFT-Git result, reversion to a negative result occurred in 1/6 (16%) recruits, whereas it occurred in 8/12 (66%) subjects after deployment or with other risk factors (P = 0.046). The quantitative result was significantly lower in subjects with reversion than in those with consistent positive results (P = 0.017). This study confirmed a low rate of positive QFT-Git results among military personnel with a positive TST result after deployment, supporting the hypothesis of exposure to NTM. Reversion of the majority of initially low-positive QFT-Git results indicates that QFT-Git may be useful for the diagnosis of later reinfections.
基于结核菌素皮肤试验（TST）结果来治疗潜伏性结核分枝杆菌感染并不准确，因为在接种牛分枝杆菌卡介苗（BCG）或接触非结核分枝杆菌（NTM）后会出现TST假阳性结果。γ干扰素释放试验（IGRAs）基于结核分枝杆菌特异性抗原。在之前一项针对未接种BCG的军事人员的研究中，部署后TST结果呈阳性大多与IGRA结果呈阴性相关，提示接触过NTM。关于IGRAs动态变化的数据有限且存在争议。本研究旨在重新评估TST假阳性结果的发生率，并评估结核感染T细胞检测（QFT-Git）在TST结果呈阳性的军事人员中的动态变化情况。在纳入研究时进行QFT-Git检测，并在2、6、12以及18或24个月后重复检测。192名参与者中，17名是新兵，175名是在部署后（n = 169）或因旅行或医疗工作接受筛查。分别在7/17（41.2%）和12/174（6.9%）的参与者中观察到基线QFT-Git结果呈阳性。在随访期间，163/165（98.8%）的参与者QFT-Git结果呈阴性且维持阴性。在18名初始QFT-Git结果呈阳性的受试者中，1/6（16%）的新兵结果转为阴性，而在部署后或有其他风险因素的受试者中，8/12（66%）的结果转为阴性（P = 0.046）。结果转为阴性的受试者其定量结果显著低于结果持续呈阳性的受试者（P = 0.017）。本研究证实，部署后TST结果呈阳性的军事人员中QFT-Git结果呈阳性的发生率较低，支持接触NTM的假说。大多数初始低阳性的QFT-Git结果转为阴性表明，QFT-Git可能有助于诊断后期再次感染。
