Asanté™ HIV-1 Rapid Recency® Assay Evaluation Report

This is the official assay evaluation report on Sedia Biosciences Corporation's Asanté™ HIV-1 Rapid Recency® Assay by the Consortium for the Evaluation and Performance of HIV Incidence Assays (CEPHIA).

Summary

Background: Monitoring the prevalence of HIV provides a blunt tool for understanding both recent transmission rates and the impact of behavioural changes or public health interventions on these rates. Consequently, there has been increasing application of assays that are able to distinguish between ‘recently’ acquired HIV-1 infections and ‘long-standing’ infections, to estimate HIV incidence within cross-sectional surveys. A comparative analysis of these existing incidence assays is a logical and necessary next step to facilitate the introduction of HIV incidence assays into wide use.

Evaluation Panel: The CEPIHA Evaluation Panel consists of 2,499 uniquely-labelled HIV-1-positive plasma specimens1 obtained from 928 distinct subjects, and was provided in 5 sets of 500 specimens each. 75 of these specimens represent 25 aliquots of each of 3 underlying specimens, and acted as (unmarked) controls. Laboratories were blinded to the specimen background information.

Data Analysis: The critical assay/recent infection testing algorithm (RITA) characteristics for cross-sectional incidence estimation, namely the mean duration of recent infection (MDRI – average time ‘recent’ while infected for less than some time !) and false-recent rate (FRR – probability of a ‘recent’ result for an individual infected for longer than !), were estimated in a number of specimen sets. The MDRI of the AsantéTM HIV-1 Rapid Recency® Assay by itself (excluding treated subjects and identified elite controllers in the CEPHIA evaluation panel) when recency discrimination is made visually was estimated at 105 days (95% confidence interval 86-125). When the electronic reader device is used at the standard threshold, the MDRI was 197 days (171-224). The FRR in the same specimen set is 1.6% and 3.6% respectively. High FRRs occur amongst treated subjects (53.5% and 58.1%) and elite controllers (11.5% and 16.0%).

Technical Appraisal: This assay is a commercially available assay developed specifically for the purpose of differentiating recent from longstanding infections in cross-sectional studies. It is a lateral flow point of collection immunoassay requiring minimal apparatus available to most laboratories. The assay comes as individual tests in a 20 or 100 batch format and is stored at 2-30oC. No EQA scheme is currently available. The assay is simple to perform following training.

Conclusions: This product does not fulfil all ‘ideal’ components of the Target Product Profile (TPP) for use in cross sectional incidence assays but does reach all acceptable criteria. We are in agreement with the company that this assay should not be used as a standalone assay but feel it may be useful as part of a recent infection testing algorithm.