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

Abstract

Background: Decreasing tuberculosis (TB) mortality is constrained by diagnostic and treatment delays. The World Health Organization (WHO) recently actively recommended the point-of-care Alere Determine Lipoarabinomannan Ag assay (AlereLAM) to assist in the diagnosis of tuberculosis in specific HIV-infected outpatients. Objectives: The primary objective of this study was to compare time to ambulatory TB treatment in HIV-infected adults with CD4 ≤ 100 cells/μL before and after (‘primary comparison groups’) availability of AlereLAM. In pre-specified subgroups, we prospectively assessed AlereLAM-positive prevalence. Method: Clinicians prospectively performed AlereLAM in HIV-infected adults with TB symptoms and either CD4 ≤ 100 cells/μL or ‘seriously ill’ criteria. In a retrospective arm of equal duration, clinicians retrospectively collected data on HIV-infected adults with CD4 ≤ 100 cells/μL who initiated TB treatment. Results: A total of 115 prospectively eligible adults (of whom 55 had CD4 ≤ 100 cells/μL) and 77 retrospectively eligible patients were included. In the primary comparison groups, the retrospective and prospective arms had similar age and sex distribution. With availability of AlereLAM, the time to TB treatment decreased from a median of 4 to 3 days (p = 0.0557). With availability of AlereLAM, same-day TB treatment initiation rose from 9.1% to 32.7% (p = 0.0006). In those with CD4 ≤ 100 only, those with ‘seriously ill’ criteria only, and in those meeting either, or both, of these criteria, AlereLAM was positive in 10.5%, 21.9%, 34.8% and 48.4% respectively. Conclusion: Availability of AlereLAM led to more patients initiating same-day TB treatment. Using both CD4 ≤ 100 and ‘seriously ill’ criteria gave the greatest yield. Results of this study have informed local policy design.

Keywords

• tuberculosis
• lipoarabinomannan
• ambulatory
• outpatient
• point-of-care
• urine
• hiv
• diagnostic