Rationale: C-reactive protein (CRP)-based tuberculosis (TB) screening is recommended for people with HIV (PWH). However, its performance among people without HIV and in diverse settings is unknown. Objectives: In a multi-country study, we aimed to determine whether CRP meets the minimum accuracy targets (sensitivity ≥90%, specificity ≥70%) for an effective TB screening test. Methods/Measurements: Consecutive outpatient adults with cough ≥2 weeks from five TB endemic countries in Africa and Asia had baseline blood collected for point-of-care CRP testing and HIV and diabetes screening. Sputum samples were collected for Xpert MTB/RIF Ultra (Xpert) testing and culture. CRP sensitivity and specificity (5 mg/L cut-point) was determined in reference to sputum test results and compared by country, sex, and HIV and diabetes status. Variables affecting CRP performance were identified using a multivariate receiver operating characteristic (ROC) regression model. Results: Among 2904 participants, of whom 613 (21%) had microbiologically-confirmed TB, CRP sensitivity was 84% (95% CI: 81-87%) and specificity was 61% (95% CI: 59-63%). CRP accuracy varied geographically, with higher sensitivity in African countries (≥91%) than Asian countries (64-82%). Sensitivity was higher among men than women (87% vs. 79%, difference +8%, 95% CI: 1-15%) and specificity was higher among people without HIV than PWH (64% vs. 45%, difference +19%, 95% CI: 13-25%). ROC regression identified country and measures of TB disease severity as predictors of CRP performance. Conclusions: Overall, CRP did not achieve the minimum accuracy targets and its performance varied by setting and in some sub-groups, likely reflecting population differences in mycobacterial load.

中文翻译：

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基于 C 反应蛋白的结核病症状筛查：一项诊断准确性研究。


理由：建议对 HIV 感染者 （PWH） 进行基于 C 反应蛋白 （CRP） 的结核病 （TB） 筛查。然而，它在未感染 HIV 的人和不同环境中的表现尚不清楚。目的： 在一项多国研究中，我们旨在确定 CRP 是否满足有效 TB 筛查测试的最低准确性目标 （敏感性 ≥90%，特异性 ≥70%）。方法/测量： 来自非洲和亚洲五个结核病流行国家的连续门诊成人咳嗽 ≥2 周，收集基线血液用于床旁 CRP 检测和 HIV 和糖尿病筛查。收集痰液样本用于 Xpert MTB/RIF Ultra （Xpert） 检测和培养。参考痰液检查结果确定 CRP 敏感性和特异性 （5 mg/L 切点），并按国家、性别、HIV 和糖尿病状况进行比较。使用多变量受试者工作特征 （ROC） 回归模型确定影响 CRP 性能的变量。结果： 在 2904 名参与者中，其中 613 名 （21%） 患有经微生物学证实的结核病，CRP 敏感性为 84% （95% CI： 81-87%） 和特异性为 61% （95% CI： 59-63%）。CRP 准确性因地域而异，非洲国家的敏感性 （≥91%） 高于亚洲国家 （64-82%）。男性的敏感性高于女性 （87% vs. 79%，差异 +8%，95% CI： 1-15%），无 HIV 人群的特异性高于 PWH （64% vs. 45%，差异 +19%，95% CI： 13-25%）。ROC 回归分析确定了国家和结核病严重程度的指标作为 CRP 性能的预测因子。结论： 总体而言，CRP 未达到最低准确率目标，其性能因设置和某些亚组而异，可能反映了分枝杆菌载量的种群差异。