Abstract

BACKGROUND: Point-of-care (POC) CD4 testing increases patient accessibility to assessment of antiretroviral therapy eligibility. This review evaluates field performance in low and middle-income countries (LMICs) of currently available POC CD4 technologies. METHODS: Eight electronic databases were searched for field studies published between January 2005 and January 2015 of six POC CD4 platforms: PointCare NOW, Alere Pima CD4, Daktari CD4 Counter, CyFlow® CD4 miniPOC, BD FACSPresto, and MyT4 CD4. Due to limited data availability, meta-analysis was conducted only for diagnostic performance of Pima at a threshold of 350 cells/mul, applying a bivariate multi-level random-effects modelling approach. A covariate extended model was also explored to test for difference in diagnostic performance between capillary and venous blood. RESULTS: Twenty seven studies were included. Published field study results were found for three of the six POC CD4 tests, 24 of which used Pima. For Pima, test failure rates varied from 2 to 23 % across study settings. Pooled sensitivity and specificity were 0.92 (95 % CI = 0.88-0.95) and 0.87 (95 % CI = 0.85-0.88) respectively. Diagnostic performance by blood sample type (venous vs. capillary) revealed non-significant differences in sensitivity (0.94 vs 0.89) and specificity (0.86 vs 0.87), respectively in the extended model (Wald chi2(2) = 4.77, p = 0.09). CONCLUSIONS: POC CD4 testing can provides reliable results for making treatment decision under field conditions in low-resource settings. The Pima test shows a good diagnostic performance at CD4 cut-off of 350 cells/mul. More data are required to evaluate performance of POC CD4 testing using venous versus capillary blood in LMICs which might otherwise influence clinical practice.

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Funding was provided by the National Health and Medical Research Council of Australia (NHMRC) (Project grant GNT 1063725, and Career Development Fellowship to S. Luchters. Infrastructure for Research Institutes Support Scheme Grant. Suzanne Crowe is a recipient of an NHMRC Principle Research fellowship). Minh Pham received support via an International Postgraduate Research Scholarship (IPRS) from the Commonwealth of Australia and the Victorian International Research Scholarship (VIRS) from State Government of Victoria, Australia (VIRS).