Montreal Chest Institute, McGill University, Montreal, Quebec, Canada.
Indian J Med Res. 2011 Mar;133(3):257-66.
Latent tuberculosis infection (LTBI) can be detected with immune based tests such as the tuberculin skin test (TST) or interferon gamma release assays (IGRA). Therapy for those with positive tests can reduce the subsequent risk of re-activation and development of active TB. Current standard therapy is isoniazid (INH) which reduce the risk of active TB by as much as 90 per cent if taken daily for 9 months. However, this lengthy duration of therapy discourages patients, and the risk of serious adverse events such as hepatotoxicity, discourages both patients and providers. As a result completion of INH therapy is less than 50 per cent in many programmes. However, programmes that offer close follow up with supportive staff who emphasize patient education, have reported much better results. The problems with INH have stimulated development and evaluation of several shorter regimens. One alternative was two months daily rifampin and pyrazinamide; this regimen has been largely abandoned due to unacceptably high rates of hepatotoxicity and poor tolerability. The combination of INH and rifampin, taken for 3 or 4 months, has efficacy equivalent to 6 months INH albeit with somewhat increased hepatotoxicity. Four months rifampin has efficacy at least equivalent to 6 months INH but there are inadequate trial data on efficacy. The safety of this regimen has been demonstrated repeatedly. Most recently, a regimen of 3 months INH rifapentine taken once weekly under direct observation has been evaluated in a large scale trial. Results have not yet been published, but if this regimen is as effective as INH, this may be a very good alternative. However, close monitoring and surveillance is strongly suggested for the first few years after its introduction. Evidence from several randomized trials has shown that the benefits of LTBI therapy is only in individuals who are tuberculin skin test (TST) positive even among those with HIV infection. Hence, LTBI therapy should be given only to those with positive tests for LTBI. We conclude that LTBI therapy is considerably underutilized in many settings, particularly in low and middle income countries.
潜伏性结核感染（LTBI）可以通过免疫检测方法（如结核菌素皮肤试验（TST）或干扰素γ释放试验（IGRA））进行检测。对检测结果阳性的患者进行治疗可以降低随后发生结核再激活和发展为活动性结核病的风险。目前的标准治疗方法是异烟肼（INH），如果每天服用 9 个月，可将活动性结核病的风险降低多达 90%。然而，这种漫长的治疗时间会使患者望而却步，而且严重不良反应（如肝毒性）的风险也会使患者和医务人员望而却步。因此，许多方案中的 INH 治疗完成率不到 50%。然而，提供密切随访和支持性工作人员的方案，强调患者教育，报告的结果要好得多。INH 存在的问题刺激了几种较短疗程方案的开发和评估。一种替代方案是两个月每天服用利福平加吡嗪酰胺；由于肝毒性发生率高和耐受性差，该方案已基本被放弃。INH 和利福平联合使用 3 或 4 个月的方案，其疗效与 6 个月 INH 相当，但肝毒性略有增加。4 个月利福平的疗效至少与 6 个月 INH 相当，但疗效的试验数据不足。该方案的安全性已反复得到证实。最近，一项在大规模试验中评估了 3 个月 INH 利福喷丁每周一次的直接观察方案。结果尚未公布，但如果该方案与 INH 同样有效，这可能是一个非常好的替代方案。然而，在引入后的头几年，强烈建议对其进行密切监测和监测。几项随机试验的证据表明，LTBI 治疗的益处仅在结核菌素皮肤试验（TST）阳性的个体中，即使在 HIV 感染者中也是如此。因此，LTBI 治疗仅应给予 LTBI 检测阳性的个体。我们的结论是，LTBI 治疗在许多情况下（特别是在中低收入国家）未得到充分利用。
