Department of Medicine, Hospital Nacional Hipólito Unanue, Lima, Peru.
PLoS One. 2011 Apr 5;6(4):e18486. doi: 10.1371/journal.pone.0018486.
Clinical suspects of pulmonary tuberculosis in which the sputum smears are negative for acid fast bacilli represent a diagnostic challenge in resource constrained settings. Our objective was to validate an existing clinical-radiographic score that assessed the probability of smear-negative pulmonary tuberculosis (SNPT) in high incidence settings in Peru.
METHODOLOGY/PRINCIPAL FINDINGS: We included in two referral hospitals in Lima patients with clinical suspicion of pulmonary tuberculosis and two or more negative sputum smears. Using a published but not externally validated score, patients were classified as having low, intermediate or high probability of pulmonary tuberculosis. The reference standard for the diagnosis of tuberculosis was a positive sputum culture in at least one of 2 liquid (MGIT or Middlebrook 7H9) and 1 solid (Ogawa) media. Prevalence of tuberculosis was calculated in each of the three probability groups. 684 patients were included. 184 (27.8%) had a diagnosis of pulmonary tuberculosis. The score did not perform well in patients with a previous history of pulmonary tuberculosis. In patients without, the prevalence of tuberculosis was 5.1%, 31.7% and 72% in the low, intermediate and high probability group respectively. The area under de ROC curve was 0.76 (95% CI 0.72-0.80) and scores ≥6 had a positive LR of 10.9.
CONCLUSIONS/SIGNIFICANCE: In smear negative suspects without previous history of tuberculosis, the clinical-radiographic score can be used as a tool to assess the probability of pulmonary tuberculosis and to guide the decision to initiate or defer treatment or to requesting additional tests.
在资源有限的环境中，痰涂片抗酸杆菌阴性的疑似肺结核患者的诊断具有挑战性。我们的目的是验证一种现有的临床影像学评分，该评分用于评估秘鲁高发地区涂片阴性肺结核（SNPT）的可能性。
方法/主要发现：我们纳入了利马两家转诊医院中具有肺结核临床疑似症状且有两次或以上阴性痰涂片的患者。使用已发表但未经外部验证的评分，将患者分为肺结核低、中、高概率组。肺结核的诊断标准为至少两种液体（MGIT 或 Middlebrook 7H9）和一种固体（Ogawa）培养基中的一种培养出阳性痰培养。在三个概率组中分别计算了结核病的患病率。共纳入 684 例患者。184 例（27.8%）患者诊断为肺结核。该评分在有既往肺结核病史的患者中表现不佳。在无既往病史的患者中，肺结核的患病率分别为低、中、高概率组的 5.1%、31.7%和 72%。ROC 曲线下面积为 0.76（95%CI 0.72-0.80），评分≥6 时阳性似然比为 10.9。
结论/意义：在无既往肺结核病史的痰涂片阴性疑似患者中，临床影像学评分可作为评估肺结核可能性的工具，有助于指导是否开始或推迟治疗或请求进行额外检查的决策。
