Evaluation of a BioRad Avidity assay for identification of recent HIV-1 infections using dried serum or plasma spots

• Published in: Journal of virological methods Vol. 266; pp. 114 - 120
• Main Authors: Hauser, Andrea, Heiden, Matthias an der, Meixenberger, Karolin, Han, Orjin, Fiedler, Stefan, Hanke, Kirsten, Koppe, Uwe, Hofmann, Alexandra, Bremer, Viviane, Bartmeyer, Barbara, Kuecherer, Claudia, Bannert, Norbert
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-04-2019
• Subjects: Antibody Affinity; Biological Assay; Dried Blood Spot Testing - methods; Enzyme-Linked Immunosorbent Assay - methods; Female; HIV Antibodies - blood; HIV Antibodies - immunology; HIV Infections - diagnosis; HIV Infections - immunology; Humans; Male; Sensitivity and Specificity
• ISSN: 0166-0934; 1879-0984
• DOI: 10.1016/j.jviromet.2019.02.002

•Evaluation of an avidity-based recency-assay using a modified protocol of the European BioRad Geenscreen™ HIV-1/2 ELISA (‘BioRad Europe Avidity’).•Mean duration of recent infection is 233 days (95% IQR: 174–351) for the subtype mix and 219 days (95% IQR: 162–340) for subtype B alone.•Concordance with the US American BioRad Avidity was high with 96.4%.•The false recent rate with 6.0% for all and 5.7% for subtype B is comparable to the BED.•Suitable alternative to replace the BED in the national incidence surveillance in Germany.
Serological methods to differentiate between recently acquired and established HIV-1 infections are a useful tool in the HIV-surveillance to characterize the epidemic, identify groups at risk and assess HIV-preventive interventions. Therefore, an avidity-based, modified BioRad Genscreen™ HIV-1/2 assay (BRAEUR) was evaluated according to the avidity-based, modified BioRad HIV-1/2 Plus O protocol (BRAUSA). Overall, 692 well defined samples (82.5% B and 17.5% non-B subtypes) from recent (<180 days, n = 239), intermediate (181–364 days, n = 35) or long term infections (≥365 days, n = 419) were used to determine a ‘mean duration of recent infection’ (MDRI), a ‘median DRI’ (MdDRI), the false recent rate (FRR), and concordance between the BRAs and the Sedia BED HIV-1 Capture enzyme immunoassay (BED). The optimal avidity index cut-off was determined to be 70% resulting in an MDRI of 233 days (95% IQR: 174–351) and an MdDRI of 171 days (95% IQR: 142–212). Concordance with the BRAUSA was high with 96.4%. The FRR of 6.0% as well as the MdDRI are similar to the BED (8.4%; 170 (139–214) days). Therefore, the BRAEUR is a suitable alternative to replace the BED and trend analysis will be feasible after minimal adjustments for the MdDRI and the MDRI.