The Desmond Tutu HIV Centre, Institute for Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
AIDS. 2012 Aug 24;26(13):1635-43. doi: 10.1097/QAD.0b013e3283553685.
A low-cost point-of-care urine assay for lipoarabinomannan (LAM) used for screening patients prior to antiretroviral therapy (ART) rapidly diagnoses a proportion of tuberculosis (TB) cases. We determined the characteristics and outcomes of such patients.
Adults enrolling in a South African township ART clinic were systematically screened for pulmonary TB by testing paired sputum samples using microscopy, liquid culture and Xpert MTB/RIF in a centralized laboratory. Stored urine samples were retrospectively tested for LAM using the Determine TB-LAM assay, but results did not inform treatment. Patients were followed up in the routine ART service and early (90-day) programmatic outcomes were determined. Analysis was restricted to those with CD4 cell counts below 200 cells/μl.
Of patients with CD4 cell counts below 200 cells/μl and complete results (n=325), 59 (18.2%) had culture-positive TB. Of these, 23 (39%) patients tested urine LAM-positive and 36 (61%) urine LAM-negative. Patients with LAM-positive TB had much lower CD4 cell counts, higher plasma viral loads, lower haemoglobin concentrations and lower BMIs compared to those with LAM-negative TB. They also had evidence of higher mycobacterial load, more frequently testing sputum smear-positive, Xpert-positive (sputum and urine) and having a shorter time to sputum culture positivity. Of five (8.5%) patients who died, four did so before TB treatment was started. All five retrospectively tested LAM-positive.
A low-cost point-of-care urine test for LAM rapidly diagnoses a sub-group of cases with advanced HIV-associated TB and poor prognosis. If used in combination with laboratory-based diagnostics, treatment delays would decrease and survival might be improved.
一种用于抗逆转录病毒治疗 (ART) 前筛查患者的低成本即时尿液脂阿拉伯甘露聚糖 (LAM) 检测方法可快速诊断一部分结核病 (TB) 病例。我们确定了这些患者的特征和结局。
在南非一个乡镇的 ART 诊所，通过在中央实验室使用显微镜、液体培养和 Xpert MTB/RIF 对配对的痰液样本进行检测，对成年人进行系统的肺结核筛查。使用 Determine TB-LAM 检测方法对储存的尿液样本进行回顾性检测 LAM，但检测结果不影响治疗。患者在常规的 ART 服务中接受随访，并确定早期（90 天）的规划结局。分析仅限于 CD4 细胞计数低于 200 个/μl 的患者。
在 CD4 细胞计数低于 200 个/μl 且结果完整的患者中（n=325），有 59 例（18.2%）培养阳性的 TB。其中，23 例（39%）患者尿液 LAM 阳性，36 例（61%）尿液 LAM 阴性。LAM 阳性 TB 患者的 CD4 细胞计数明显更低，血浆病毒载量更高，血红蛋白浓度和 BMI 更低，与 LAM 阴性 TB 患者相比。他们还具有更高的分枝杆菌负荷的证据，更频繁地检测到痰涂片阳性、Xpert 阳性（痰和尿液），且痰培养阳性的时间更短。在 5 例（8.5%）死亡的患者中，有 4 例在开始 TB 治疗前死亡。这五例患者均回溯性检测 LAM 阳性。
一种用于 LAM 的即时尿液低成本检测方法可快速诊断一组晚期 HIV 相关 TB 和预后不良的病例。如果与实验室诊断方法联合使用，将减少治疗延迟并可能提高生存率。
