Division of Emergency Medicine, University of Cape Town, Cape Town, South Africa.
Division of Emergency Medicine, Stellenbosch University, Cape Town, South Africa.
J Acquir Immune Defic Syndr. 2019 May 1;81(1):e10-e14. doi: 10.1097/QAI.0000000000002002.
The urine lipoarabinomannan (LAM) lateral flow assay is a point-of-care test to diagnose HIV-associated tuberculosis (TB). We assessed the performance of urine LAM in HIV-positive patients presenting to the emergency center and evaluated the interobserver agreement between emergency center physicians and laboratory technologists.
A cross-sectional diagnostic study was performed at the emergency center of a district hospital in a high HIV-prevalence community in South Africa.
Consecutive HIV-positive adults presenting with ≥1 WHO TB symptom were enrolled over a 16-month period. A urine LAM test was performed at point-of-care by an emergency physician and interpreted independently by 2 physicians. A second test was performed in the laboratory and interpreted independently by 2 laboratory technologists. The reference standard was a positive TB culture or Xpert MTB/RIF test on sputum or appropriate extrapulmonary samples. We compared diagnostic accuracy and reproducibility of urine LAM between point-of-care readers and laboratory readers.
One thousand three hundred eighty-eight samples (median, 3 samples/participant) were sent for TB microbiology tests in 411 participants; 170 had confirmed TB (41.4%). Point-of-care and laboratory-performed urine LAM had similar sensitivity (41.8% vs 42.0%, P = 1.0) and specificity (90.5% vs 87.5%, P = 0.23). Moderate agreement was found between point-of-care and laboratory testing (κ = 0.62), but there was strong agreement between point-of-care readers (κ = 0.95) and between laboratory readers (κ = 0.94). Positive percent agreement between point-of-care and laboratory readers was 68% and negative percent agreement 92%.
There is no diagnostic accuracy advantage in laboratory-performed versus point-of-care-performed urine LAM tests in emergency care centers in high-burden settings.
尿液脂阿拉伯甘露聚糖（LAM）侧向流动检测是一种用于诊断 HIV 相关结核病（TB）的即时检测方法。我们评估了尿液 LAM 在出现于急诊中心的 HIV 阳性患者中的表现，并评估了急诊中心医生和实验室技术员之间的观察者间一致性。
在南非一个高 HIV 流行社区的地区医院的急诊中心进行了一项横断面诊断研究。
在 16 个月的时间内，连续纳入出现≥1 项世界卫生组织（WHO）TB 症状的 HIV 阳性成人。由急诊医师在现场进行尿液 LAM 检测，并由 2 名医生独立进行解读。在实验室进行第二次检测，并由 2 名实验室技术员独立进行解读。参考标准是痰液或适当的肺外样本中阳性的 TB 培养物或 Xpert MTB/RIF 检测。我们比较了现场读者和实验室读者之间尿液 LAM 的诊断准确性和重现性。
在 411 名参与者中，共发送了 1388 份样本（中位数为 3 份/参与者）进行 TB 微生物学检测；170 人确诊为 TB（41.4%）。现场和实验室进行的尿液 LAM 具有相似的敏感性（41.8%比 42.0%，P=1.0）和特异性（90.5%比 87.5%，P=0.23）。现场和实验室检测之间存在中度一致性（κ=0.62），但现场读者之间（κ=0.95）和实验室读者之间（κ=0.94）存在高度一致性。现场和实验室读者之间的阳性百分比一致率为 68%，阴性百分比一致率为 92%。
在高负担环境中的急诊中心，实验室进行的与现场进行的尿液 LAM 检测在诊断准确性方面没有优势。
