Using a simplified human immunodeficiency virus type 1 p24 antigen assay to diagnose pediatric HIV-infection in Malawi

J Clin Virol. 2010 Dec;49(4):299-302. doi: 10.1016/j.jcv.2010.08.013. Epub 2010 Sep 19.

Abstract

Background: There is a worldwide need for a pediatric HIV-1 diagnostic test that has a high diagnostic accuracy, is technically simple and cost efficient. The Up24 HIV-1 assay, which requires both the HIV-1 p24 ELISA and the ELAST signal amplification kit, has previously been shown to be a robust tool to diagnose pediatric HIV-1 from dried whole blood spots (DBS) (Cachafeiro et al., JCM 2009;47:459-62(13)). In order to make the assay more accessible to a resource-limited clinical setting, we eliminated the ELAST system, which simplified the Up24 assay, reduced its cost, and tested the accuracy of the modified assay in a rural Malawian hospital.

Objectives: In this proof of concept study, we tested the ability of a simplified Up24 antigen assay, without ELAST, to detect HIV-1 on DBS obtained via heel prick from 6-week-old Malawian infants.

Study design: A case-control study of DBS collected from 113 HIV-infected and 109 HIV-negative infants, using the HIV-1 DNA PCR assay as the reference standard.

Results: The simplified HIV-1 Up24 assay had a sensitivity and specificity of 84% and 98%, respectively. When HIV-1 prevalence is 15%, the positive- and negative-predictive values are 89% and 97%, respectively.

Conclusion: The simplified Up24 assay has a good positive- and a robust negative-predictive values, is easier to perform and has a reduced cost compared to both HIV DNA PCR and Up24 assays. With additional testing, the simplified Up24 assay has the potential to increase global access to pediatric HIV-1 diagnostics.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood / virology*
  • Case-Control Studies
  • Enzyme-Linked Immunosorbent Assay / methods
  • HIV Core Protein p24 / analysis*
  • HIV Infections / diagnosis*
  • HIV Infections / virology
  • HIV-1 / isolation & purification*
  • Humans
  • Infant
  • Malawi
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • Virology / methods*

Substances

  • HIV Core Protein p24
  • p24 protein, Human Immunodeficiency Virus Type 1