Evaluation of the performance of a new automated HIV combination assay

Background More and more countries test for HIV infection using combination assays that simultaneously detect p24 antigen and HIV antibodies. Objective To assess the performance of a new HIV combo assay: LIAISON ® XL murex HIV Ab/Ag HT. Study design The assays were examined with a total of 3090 samples that included 769 selected HIV antibody-negative samples, 1849 unselected HIV samples, 15 HIV-1 p24 Ag reference samples, 90 primary HIV-1 infection (PHI) samples, 167 HIV-1 antibody-positive samples (well characterized of groups M and O), 95 HIV-1 antibody-positive samples and 105 HIV-2 antibody-positive samples. Results The specificity of the LIAISON ® XL murex HIV Ab/Ag HT was 99.7%. The analytical sensitivity of Ag p24 of the LIAISON ® XL murex HIV Ab/Ag HT was 0.58 IU/mL and 9.93 pg/mL when using WHO and French national standards, respectively. All screened HIV subtypes was identified by this assay. Also, 90 PHI specimens were detected by this screening assay. Conclusion The sensitivity and specificity of the LIAISON ® XL murex HIV Ab/Ag HT assay are high. Hence the assay offers automated high-throughput screening with ability to detect primary infection.