Analytical and clinical performance evaluation of enhanced chemiluminescence-based fourth-generation HIV combo assay: Report from tertiary health-care setup in North India.

ABSTRACT

INTRODUCTION: HIV fourth-generation assay, designed for the detection of HIV p24 antigen along with anti-HIV antibodies of both immunoglobulin M and immunoglobulin G type against HIV 1 and HIV 2 viral antigens, have helped in the early detection of HIV infection and supports in minimizing the transmission risk in the acute phase of infection. The objective of this study was to evaluate the analytical and clinical performance of HIV fourth-generation assay based on enhanced chemiluminescence technology. MATERIALS AND METHODS: The analytical performance of the assay was evaluated in terms of accuracy, precision, limit of detection, type of sample (serum vs. plasma), cross-reactivity (with other transfusion transmissible infections markers), and interference (with endogenous substances). Proficiency control material included kit-controls, archived known positive donor samples, third-party controls, and World Health Organization (WHO)/National Institute for Biological Standards and Controls (NIBSC, MHRA, UK) controls. The clinical performance was evaluated using routine donor and patient samples received during the study period. RESULTS: HIV fourth-generation assay showed reliable and reproducible results measured in terms of coefficient of variation % with kit-controls, archived known positive donor samples, third-party controls, and WHO international standards for anti-HIV 1 and 2 antibodies, HIV1 p24 antigens and HIV2 p26 antigen controls. The analytical sensitivity of the HIV fourth-generation assay was found to be 0.1 IU/mL of HIV1 p24 antigen control and there was no cross-reactivity or interference observed. In the clinical performance of the assay, HIV fourth-generation assay showed reliable performance in both donor and patient samples. CONCLUSION: HIV fourth-generation assay meets the requirements for its use as a screening assay for HIV infection based on the analytical and clinical performance of the assay.