Publications & Reports

Performance characteristics of an instrument-free point-of-care CD4 test (VISITECT(R)CD4) for use in resource-limited settings.

Vidhyavathi V, Iqbal HS, Kanthamani K, Solomon SS, Nandagopal P, Luchters S, Pham MD, Forbes J, Crowe SM, McMurran C, Anderson DA, Balakrishnan P
YRG Centre for AIDS Research and Education, Voluntary Health Services, Chennai, India.

Abstract

OBJECTIVE: CD4+ T lymphocyte count remains the most common biomarker of immune status and disease progression in human immunodeficiency virus (HIV)-positive individuals. VISITECT®CD4 is an instrument-free, low-cost point-of-care CD4 test with a cut-off of 350 CD4 cells/muL. This study aimed to evaluate VISITECT®CD4 test’s diagnostic accuracy. METHODS: Two hundred HIV-positive patients attending a tertiary HIV centre in South India were recruited. Patients provided venous blood for reference and VISITECT®CD4 tests. An additional finger-prick blood sample was obtained for VISITECT®CD4. VISITECT®CD4’s diagnostic performance in identifying individuals with CD4 counts </=350 cells/muL was assessed by calculating sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) taking flow cytometry as the reference. RESULTS: The overall agreement between VISITECT®CD4 and flow cytometry was 89.5% using venous blood and 81.5% using finger-prick blood. VISITECT®CD4 showed better performance using venous blood [sensitivity: 96.6% (95% confidence interval: 92.1%-98.9%), specificity: 70.9% (57.1%-82.4%), PPV: 89.7% (83.9%-94.0%) and NPV: 88.6% (75.4%-96.2%)] than using finger-prick blood [sensitivity: 84.8% (77.9%-90.2%), specificity: 72.7% (59.0%-83.9%), PPV: 89.1% (82.7%-93.8%) and NPV: 64.5% (51.3%-76.3%)]. CONCLUSION: VISITECT®CD4 performed well using venous blood, demonstrating its potential utility in decentralization of CD4 testing services in resource-constrained settings.

Link to publisher’s web site

Publication

  • Journal: The Journal of International Medical Research
  • Published: 01/09/2020
  • Volume: 48
  • Issue: 9
  • Pagination: 300060520955028

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