Utility of the lateral flow urine lipoarabinomannan tuberculosis assay in patients with advanced HIV disease at antiretroviral therapy centres in Mumbai, India

Abstract

Background People with Advanced HIV Disease (AHD) are at higher risk of TB coinfection and mortality. However, there are challenges in TB diagnosis with the currently recommended diagnostic tools. WHO recommends lateral flow urine lipoarabinomannan (LF-LAM) assay to assist TB diagnosis among AHD patients. We assessed the utility and acceptability of using urine LF-LAM assay for TB diagnosis among patients at public Antiretroviral Therapy (ART) Centres in Mumbai. Methods The cross-sectional study was conducted among adult AHD patients accessing care from 17 ART centres during November,2020-June, 2021. Urine LF-LAM was offered as routine care for eligible patients in combination with standard diagnostic tests. We calculated the proportion of positive LF-LAM results by CD4 categories and TB symptoms and performed multivariable logistic regression to determine the factors associated with LF-LAM positivity. Results Among 2,390 patients, the majority (74.5%) had CD4 between 101–200 cells/mm3. The mean age was 43.7 years (SD:10.6), 68.6% were male, 8.4% had TB symptoms and 88.0% were on ART. The overall proportion of patients with urine LF-LAM positive results was 6.4%. Among PLHIV with CD4≤100 cells/mm3, the positivity was 43.0% and 7.7% in symptomatic and asymptomatic patients, respectively. Among PLHIV with a CD4>100 cells/mm3, the positivity was 26.7% and 2.7% in symptomatic and asymptomatic patients respectively. Urine LF-LAM positivity was higher among inpatients, ART naïve, patients on treatment for <6 months, symptomatic and in WHO clinical stage III/IV of HIV disease as compared to the reference categories. We detected an additional 131 TB cases with urine LF-LAM in combination with the standard diagnostic tests. Conclusion The study demonstrated the utility of urine LF-LAM for TB diagnosis among AHD patients and the simple, user-friendly test was acceptable as part of routine care. Inclusion of urine LF-LAM test in the current diagnostic algorithm may facilitate early TB diagnosis among AHD patients.