Quantiferon Gold Test for Detecting TB Infection in HIV/AIDS Patients in Brazil

描述(申请人提供)：结核病(TB)是艾滋病毒携带者中最常见的死亡原因。在HIV感染者中诊断潜在结核病感染(LTBI)具有挑战性，因为最常用的结核菌素皮肤试验(TST)过时了，在HIV感染和卡介苗接种人群中敏感性较差，而且操作上很难管理。世界卫生组织目前建议，在可以实施TST以检测下呼吸道合并症的地区，建议只对TST阳性的艾滋病毒感染患者提供预防性治疗。一种新的血液分析方法Quantiferon TB Gold In-Tube(QGIT)最近已被美国FDA批准用于检测LTBI，但发表的研究相对较少，有关QGIT常规使用的信息也很少，即在常规临床护理条件下的测试表现和这种血液测试的最佳操作。我们提出了一项整群随机试验(CRT)，以比较在巴西里约热内卢公共艾滋病毒诊所就诊的艾滋病毒感染者的QGIT表现与常规TST，并确定QGIT是否更快地识别潜伏感染的艾滋病毒感染者，并导致更快地开始结核病预防治疗。我们会将QGIT测试与常规的CD4监测联系起来，这将减少常规诊所工作人员的负担，并将对常规抽血的干扰降至最低。里约热内卢在TST和提供异烟肼预防性治疗方面的拖延时间非常长，等待TST的艾滋病毒感染患者患结核病的风险相当高，因此需要更好的战略。这项研究的具体目的是1)比较巴西里约热内卢HIV诊所将QGIT与CD4血液采集和TST现行护理流程标准联系起来对操作指标的影响；2)比较实施QGIT与TST标准实践的成本效益；3)探讨影响QGIT成功实施的态度和操作因素。考虑到测试的参数，我们主要关注将QGIT与常规的CD4抽血联系起来是创新和合乎逻辑的。这些发现，除了对干预措施的实施进行有组织的过程评估并确定QGIT与TST相比的成本效益外，还将提供迄今为止在发展中国家的操作环境中比较这两种测试的最佳证据，并指导这一战略在巴西和TST在诊断艾滋病毒感染患者潜伏感染方面无效的其他地区的传播和实施。

DESCRIPTION (provided by applicant): Tuberculosis (TB) is the most common cause of death among people living with HIV. Diagnosing latent tuberculosis infection (LTBI) among HIV-infected patients is challenging, as the most commonly used test, the tuberculin skin test (TST), is out-dated, has poor sensitivity in HIV-infected and BCG vaccinated populations, and is operationally difficult to administer. The World Health Organization currently recommends that in regions where the TST can be implemented to detect LTBI, provision of preventive therapy is recommended only for HIV-infected patients with a positive TST. A new blood assay, Quantiferon TB Gold In-Tube (QGIT) test, has been recently approved by the US FDA for detecting LTBI, however relatively few published studies have evaluated this assay in HIV-infected patients and little information exists about the routine use of QGIT, i.e. test performance under routine clinical care conditions and optimal operationalization of this blood test. We propose a cluster randomized trial (CRT) to compare QGIT performance in HIV-infected persons attending public HIV clinics in Rio de Janeiro, Brazil with routine TST, and to determine if QGIT more quickly identifies HIV-infected patients who are latently infected and leads to faster initiation of TB preventive therapy. We will link QGIT testing with routine CD4 monitoring which will eliminate the burden of the routine clinic staff and minimally interfere with routine blood draws. Delays in TST and provision of isoniazid preventive therapy in Rio de Janeiro are extremely long, and risk of TB disease is quite high among HIV-infected patients waiting for a TST, thus a better strategy is needed. The specific aims of the study are 1) to compare the impact of linking QGIT with CD4 blood collection and the current standard of care process of TST in HIV clinics in Rio de Janeiro, Brazil on operational metrics, 2) to compare cost-effectiveness of implementing QGIT versus standard practice of TST, and 3) to explore attitudinal and operational factors influencing successful implementation of QGIT. Our primary focus on linking QGIT with routine CD4 blood draws is innovative and logical given the parameters of the test. These findings, in addition to conducting a structured process evaluation of the implementation of the intervention and determining the cost effectiveness of QGIT compared to TST will provide the best evidence to date comparing these two tests in an operational setting in a developing country, and guide dissemination and implementation of this strategy throughout Brazil and other regions where TST is ineffective at diagnosing latent infection in HIV- infected patients.