S Lavoie1, D Caswell2, M J Gill3, K Kadkhoda4, C L Charlton5, P N Levett2, T Hatchette6, R Garceau7, J Maregmen8, T Mazzulli8, R Needle9, K Kadivar1, J Kim10. 1. National Laboratory for HIV Reference Services, National Microbiology Laboratory, Winnipeg, MB, Canada. 2. Saskatchewan Disease Control Laboratory, Regina, SK, Canada. 3. Southern Alberta HIV Clinic, Calgary, AB, Canada. 4. Cadham Provincial Public Health Laboratory, Winnipeg, MB, Canada. 5. Provincial Laboratory for Public Health, University of Alberta Hospital, Edmonton, AB, Canada. 6. Department of Pathology and Laboratory Medicine, Nova Scotia Health Authority, Halifax, NS, Canada. 7. Centre Hospitalier Universitaire-Dr G. L. Dumont, Moncton, NB, Canada. 8. Public Health Ontario Toronto Laboratory, Toronto, ON, Canada. 9. Department of Laboratory Medicine Faculty of Medicine, Memorial University of Newfoundland, NL, Canada. 10. National Laboratory for HIV Reference Services, National Microbiology Laboratory, Winnipeg, MB, Canada. Electronic address: john.kim@canada.ca.
Abstract
BACKGROUND: False-reactivity in HIV-negative specimens has been detected in HIV fourth-generation antigen/antibody or 'combo' assays which are able to detect both anti-HIV-1/HIV-2 antibodies and HIV-1 antigen. OBJECTIVES: We sought to characterize these specimens and determine the effect of heterophilic interference. STUDY DESIGN: Specimens previously testing as false-reactive on the Abbott ARCHITECT HIV Ag/Ab combo assay and re-tested on a different (Siemens ADVIA Centaur HIV Ag/Ab) assay. A subset of these specimens were also pre-treated with heterophilic blocking agents and re-tested on the Abbott assay. RESULTS: Here we report that 95% (252/264) of clinical specimens that were repeatedly reactive on the Abbott ARCHITECT HIV Ag/Ab combo assay (S/Co range, 0.94-678) were negative when re-tested on a different fourth generation HIV combo assay (Siemens ADVIA Centaur HIV Ag/Ab). All 264 samples were subsequently confirmed to be HIV negative. On a small subset (57) of specimens with available volume, pre-treatment with two different reagents (HBT; Heterophilic Blocking Tube, NABT; Non-Specific Blocking Tube) designed to block heterophilic antibody interference either eliminated (HBT) or reduced (NABT) the false reactivity when re-tested on the ARCHITECT HIV Ag/Ab combo assay. CONCLUSIONS: Our results suggest that the Abbott ARCHITECT HIV Ag/Ab combo assay can be prone to heterophilic antibody interference. Crown
BACKGROUND: False-reactivity in HIV-negative specimens has been detected in HIV fourth-generation antigen/antibody or 'combo' assays which are able to detect both anti-HIV-1/HIV-2 antibodies and HIV-1 antigen. OBJECTIVES: We sought to characterize these specimens and determine the effect of heterophilic interference. STUDY DESIGN: Specimens previously testing as false-reactive on the Abbott ARCHITECT HIV Ag/Ab combo assay and re-tested on a different (Siemens ADVIA Centaur HIV Ag/Ab) assay. A subset of these specimens were also pre-treated with heterophilic blocking agents and re-tested on the Abbott assay. RESULTS: Here we report that 95% (252/264) of clinical specimens that were repeatedly reactive on the Abbott ARCHITECT HIV Ag/Ab combo assay (S/Co range, 0.94-678) were negative when re-tested on a different fourth generation HIV combo assay (Siemens ADVIA Centaur HIV Ag/Ab). All 264 samples were subsequently confirmed to be HIV negative. On a small subset (57) of specimens with available volume, pre-treatment with two different reagents (HBT; Heterophilic Blocking Tube, NABT; Non-Specific Blocking Tube) designed to block heterophilic antibody interference either eliminated (HBT) or reduced (NABT) the false reactivity when re-tested on the ARCHITECT HIV Ag/Ab combo assay. CONCLUSIONS: Our results suggest that the Abbott ARCHITECT HIV Ag/Ab combo assay can be prone to heterophilic antibody interference. Crown
Authors: Jew Ochola; Michelle Imbach; Leigh Anne Eller; Mark de Souza; Chiaka Nwoga; June Doryne Otieno; Lucas Otieno; Eric Rono; Edwin Kamau; Trevor A Crowell; John Kevin Owuoth; Christina S Polyak; Valentine Sing'oei Journal: IDCases Date: 2020-12-25