Systematic, Point-of-Care Urine Lipoarabinomannan (Alere TB-LAM) Assay for Diagnosing Tuberculosis in Severely Immunocompromised HIV-Positive Ambulatory Patients

Abstract

Point-of-care urine-lipoarabinomannan (LAM) Alere Determine TB-LAM assay has shown utility diagnosing tuberculosis (TB) in HIV-positive, severely immunocompromised, TB-symptomatic patients. We assessed LAM results in severely immunocompromised patients, who had LAM systematically performed at new or follow-up HIV consultations. This was a prospective, observational study on consecutive ambulatory, > 15-year-old HIV-positive patients with CD4 < 100 cells/μL in Mozambique. Clinical assessments and LAM were performed for all and microscopy, Xpert, sputum culture, and chest X-ray for LAM-positive participants. Patients were followed up for 6 months. Of 360 patients, half were ART-naive. Lipoarabinomannan positivity was 11.9% (43/360), higher among symptomatic patients compared with asymptomatic: 18.5% (30/162), and 6.6% (13/198), respectively, P = 0.001. Tuberculosis was bacteriologically confirmed in 6/35 LAM-positive patients (2 of them asymptomatic). Lipoarabinomannan positivity was associated with higher risk of mortality (adjusted odds ratio [aOR]: 4.6, 95% CI: 1.3-15.6, P = 0.015). Systematic urine-LAM allows for rapid TB treatment initiation in severely immunocompromised HIV ambulatory patients and identifies patients at a higher risk of death.

Diagnostic value of Lipoarabinomannan antigen for detecting Mycobacterium tuberculosis in adults and children with or without HIV infection

“…According to the bivariate boxplot, we found the source of considerable heterogeneity. The heterogeneity may be resulted from the points outside the circle, thus we reviewed papers these points represent in Figure 3 , 20 , 64 , 79 .…”

“…64 Huerga reported the highest sensitivity (81%) and specificity (100%), but only patients with HIVpositive and CD4+ <100 cells/μl were enrolled. 79 Nonetheless, the current study has a few limitations. In terms of research design and quality assessment, not all selected studies are included in a random or continuous manner, which may result in a lack of reasonable sampling methods.…”

“… 64 Huerga reported the highest sensitivity (81%) and specificity (100%), but only patients with HIV‐positive and CD4+ <100 cells/μl were enrolled. 79 …”

Utility of urine lipoarabinomannan (LAM) in diagnosing mycobacteria infection among hospitalized HIV-positive patients

“…Cross-reactions between LAM and NTM antigens have been previously observed in patients with NTM disease (Bjerrum et al, 2020, De et al, 2020, Huerga et al, 2020, Nel et al, 2017. LAM encompasses a large family of related molecules which are expressed by all mycobacterial species.…”

Urine lipoarabinomannan for rapid tuberculosis diagnosis in HIV-infected adult outpatients in Khayelitsha

“…Other studies have been performed to assess the impact of AlereLAM on time to initiation of TB treatment in an outpatient setting. 11 , 12 , 13 The multi-centre TB-NEAT trial performed AlereLAM on biobanked urine samples and concluded that AlereLAM results would have no impact on decreasing time to initiation of TB treatment if chest X-ray facilities are available on-site and where rates of empiric TB treatment are high. 13 Despite a high burden of TB in our study’s community and generally higher healthcare resources in South Africa than some other comparable high-burden settings, the clinics in this study do not have access to on-site chest X-ray.…”