Richeldi Luca
Department of Oncology, Hematology, and Respiratory Disease, University of Modena and Reggio Emilia, 41100 Modena, Italy.
Am J Respir Crit Care Med. 2006 Oct 1;174(7):736-42. doi: 10.1164/rccm.200509-1516PP. Epub 2006 Jun 23.
Targeted testing and treatment of individuals with latent tuberculosis infection at increased risk of progression to active disease is a key element of tuberculosis control. This strategy is limited by the poor specificity of the tuberculin skin test in populations vaccinated with bacille Calmette-Guérin and its low sensitivity in immunosuppressed persons, who are at highest risk of progression. Two blood tests (T-SPOT.TB and QuantiFERON-TB Gold), based on detection of IFN-gamma released by T cells in response to M. tuberculosis-specific antigens, may offer an improvement on the skin test. However, validation is challenging due to the lack of a diagnostic gold standard. This critical appraisal of published evidence summarizes the diagnostic accuracy of the new tests. The blood tests have operational advantages over the skin test because no return visit is required, results are available by the next day, and repeated testing does not cause boosting. Both tests are significantly more specific than the skin test in populations vaccinated with bacille Calmette-Guérin. The data suggest that T-SPOT.TB may be more sensitive than the skin test. Data in groups at high risk of progression to disease are scarce, and more research is needed in these populations, but it is clear that T-SPOT.TB performs better than the skin test in young children and HIV-infected people with active tuberculosis. Incorporation of these tests into programs for targeted testing of latent tuberculosis infection will reduce false-positive and false-negative results inherent in tuberculin testing, equipping clinicians with more accurate tools for tuberculosis control and elimination in the 21st century.
对有进展为活动性疾病高风险的潜伏性结核感染个体进行针对性检测和治疗是结核病控制的关键要素。这一策略受到卡介苗接种人群中结核菌素皮肤试验特异性差以及免疫抑制人群中其敏感性低的限制，而免疫抑制人群是进展风险最高的人群。两种基于检测T细胞因结核分枝杆菌特异性抗原刺激而释放的γ干扰素的血液检测（T-SPOT.TB和QuantiFERON-TB Gold）可能比皮肤试验有所改进。然而，由于缺乏诊断金标准，验证具有挑战性。对已发表证据的这一关键评估总结了新检测方法的诊断准确性。血液检测相对于皮肤试验具有操作优势，因为无需复诊，第二天即可获得结果，且重复检测不会导致增强反应。在卡介苗接种人群中，这两种检测的特异性均显著高于皮肤试验。数据表明，T-SPOT.TB可能比皮肤试验更敏感。关于进展为疾病高风险人群的数据较少，这些人群需要更多研究，但很明显，T-SPOT.TB在幼儿和活动性结核病的HIV感染者中比皮肤试验表现更好。将这些检测纳入潜伏性结核感染针对性检测项目将减少结核菌素检测固有的假阳性和假阴性结果，为临床医生在21世纪控制和消除结核病配备更准确的工具。
