Diagnostic value of the urine lipoarabinomannan assay in HIV-positive, ambulatory patients with CD4 below 200 cells/μl in 2 low-resource settings: A prospective observational study.

BackgroundCurrent guidelines recommend the use of the lateral flow urine lipoarabinomannan assay (LAM) in HIV-positive, ambulatory patients with signs and symptoms of tuberculosis (TB) only if they are seriously ill or have CD4 count ≤ 100 cells/μl. We assessed the diagnostic yield of including LAM in TB diagnostic algorithms in HIV-positive, ambulatory patients with CD4 Methods and findingsWe conducted a prospective observational study including HIV-positive adult patients with signs and symptoms of TB and CD4 ConclusionsLAM has diagnostic value for identifying TB in HIV-positive patients with signs and symptoms of TB and advanced immunodeficiency, including those with a CD4 count of 100-199 cells/μl. In this study, the use of LAM enabled the diagnosis of TB in half of the patients with confirmed TB disease; without LAM, these patients would have been missed. The rapid identification and treatment of TB enabled by LAM may decrease overall mortality risk for these patients

Performance characteristics of finger-stick dried blood spots (DBS) on the determination of human immunodeficiency virus (HIV) treatment failure in a pediatric population in Mozambique.

Quantitative plasma viral load (VL) at 1000 copies /mL was recommended as the threshold to confirm antiretroviral therapy (ART) failure by the World Health Organization (WHO). Because of ongoing challenges of using plasma for VL testing in resource-limited settings (RLS), especially for children, this study collected 717 DBS and paired plasma samples from children receiving ART ≥1 year in Mozambique and compared the performance of DBS using Abbott's VL test with a paired plasma sample using Roche's VL test. At a cut-off of 1000 copies/mL, sensitivity of DBS using Abbott DBS VL test was 79.9%, better than 71.0% and 63.9% at 3000 and 5000 copies/mL, respectively. Specificities were 97.6%, 98.8%, 99.3% at 1000, 3000, and 5000 copies/mL, respectively. The Kappa value at 1000 copies/mL, 0.80 (95% CI: 0.73, 0.87), was higher than 0.73 (95% CI: 0.66, 0.80) and 0.66 (95% CI: 0.59, 0.73) at 3000, 5000 copies/mL, respectively, also indicating better agreement. The mean difference between the DBS and plasma VL tests with 95% limits of agreement by Bland-Altman was 0.311 (-0.908, 1.530). Among 73 children with plasma VL between 1000 to 5000 copies/mL, the DBS results were undetectable in 53 at the 1000 copies/mL threshold. While one DBS sample in the Abbott DBS VL test may be an alternative method to confirm ART failure at 1000 copies/mL threshold when a plasma sample is not an option for treatment monitoring, because of sensitivity concerns between 1,000 and 5,000 copies/ml, two DBS samples may be preferred accompanied by careful patient monitoring and repeat testing

Sensitivity, specificity, Kappa agreement, and false negativity and positivity of one Abbott DBS VL sample compared with the paired Roche plasma VL among children on ART in Mozambique.

<p>Sensitivity, specificity, Kappa agreement, and false negativity and positivity of one Abbott DBS VL sample compared with the paired Roche plasma VL among children on ART in Mozambique.</p

Misclassification of Abbott DBS viral load compared with paired Roche plasma VL among children on ART in Mozambique.

<p>Misclassification of Abbott DBS viral load compared with paired Roche plasma VL among children on ART in Mozambique.</p

Bland-Altman analysis of Roche plasma VL and Abbott DBS VL among children on ART in Mozambique.

<p>Bland-Altman analysis of Roche plasma VL and Abbott DBS VL among children on ART in Mozambique.</p

Demographic^* and clinical characteristics of children on ART in Mozambique at enrollment into DBS-plasma VL comparison study with 95% confidence interval (CI).

<p>Demographic^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0181054#t001fn001" target="_blank">*</a>} and clinical characteristics of children on ART in Mozambique at enrollment into DBS-plasma VL comparison study with 95% confidence interval (CI).</p

Plasma viral load ranges of the 72 DBS samples with plasma VL ranging from 1000 to 5000 copies/mL.

<p>Plasma viral load ranges of the 72 DBS samples with plasma VL ranging from 1000 to 5000 copies/mL.</p