A Prospective Evaluation of the Diagnostic Accuracy of the Point-of-Care VISITECT CD4 Advanced Disease Test in 7 Countries

Abstract

Abstract Background CD4 measurement is pivotal in the management of advanced human immunodeficiency virus (HIV) disease. VISITECT CD4 Advanced Disease (VISITECT; AccuBio, Ltd) is an instrument-free, point-of-care, semiquantitative test allowing visual identification of CD4 ≤ 200 cells/µL or >200 cells/ µL from finger-prick or venous blood. Methods As part of a diagnostic accuracy study of FUJIFILM SILVAMP TB LAM, people with HIV ≥18 years old were prospectively recruited in 7 countries from outpatient departments if a tuberculosis symptom was present, and from inpatient departments. Participants provided venous blood for CD4 measurement using flow cytometry (reference standard) and finger-prick blood for VISITECT (index text), performed at point-of-care. Sensitivity, specificity, and positive and negative predictive values of VISITECT to determine CD4 ≤ 200 cells/ µL were evaluated. Results Among 1604 participants, the median flow cytometry CD4 was 367 cells/µL (interquartile range, 128–626 cells/µL) and 521 (32.5%) had CD4 ≤ 200 cells/µL. VISITECT sensitivity was 92.7% (483/521; 95% confidence interval [CI], 90.1%–94.7%) and specificity was 61.4% (665/1083; 95% CI, 58.4%–64.3%). For participants with CD4 0–100, 101–200, 201–300, 301–500, and >500 cells/µL, VISITECT misclassified 4.5% (95% CI, 2.5%–7.2%), 12.5 (95% CI, 8.0%–18.2%), 74.1% (95% CI, 67.0%–80.5%), 48.0% (95% CI, 42.5%–53.6%), and 22.6% (95% CI, 19.3%–26.3%), respectively. Conclusions VISITECT's sensitivity, but not specificity, met the World Health Organization's minimal sensitivity and specificity threshold of 80% for point-of-care CD4 tests. VISITECT's quality needs to be assessed and its accuracy optimized. VISITECT’s utility as CD4 triage test should be investigated. Clinical Trials Registration. NCT04089423.