Wei Luo1, Vickie Sullivan1, Tara Smith2, Philip J Peters1, Cynthia Gay3, Emily Westheimer4, Stephanie E Cohen5, S Michele Owen1, Silvina Masciotra6. 1. Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States. 2. Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States; Oak Ridge Institute for Science and Education, United States. 3. University of North Carolina, Chapel Hill, NC, United States. 4. New York City Department of Health & Mental Hygiene, New York City, NY, United States. 5. San Francisco Department of Public Health, San Francisco, CA, United States. 6. Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA, United States. Electronic address: svm6@cdc.gov.
Abstract
BACKGROUND: In the US, the HIV diagnostic algorithm for laboratory settings recommends the use of an HIV-1/HIV-2 differentiation supplemental assay after an initial reactive antigen/antibody (Ag/Ab) assay result. Since the discontinuation of the Multispot HIV-1/HIV-2 Rapid Test (MS), the Geenius HIV-1/2 Supplemental assay (Geenius) is the only FDA-approved supplemental differentiation test. OBJECTIVE: We compared the performance of Geenius to MS and Western Blot (WB). STUDY DESIGN: The relative seroconversion plasma reactivity of Geenius and MS was assessed using a 50% cumulative frequency analysis from 17 HIV-1 seroconverters. In addition, previously characterized plasma specimens, 186 HIV-1 positive, 100 HIV-2 positive, and 93 Ag/Ab-positive/HIV-1 RNA-negative, were tested with Geenius v1.1 software. McNemar's test was used for paired comparison analysis. A subset of 48 specimens were retested with the upgraded Geenius v1.3 software. RESULTS: In HIV-1 seroconverters, the relative seroconversion reactivity was 2.5 and 2 days before the first positive HIV-1 WB for Geenius and MS, respectively. In HIV-1 positive samples, Geenius performed similarly to HIV-1 WB (p=0.1687) and MS (p=0.8312). In HIV-2 positive samples, Geenius underperformed compared to HIV-2 WB (p=0.0005) and MS (p=0.0012). When using the upgraded software among the HIV-1 positive and Ag/Ab-reactive/HIV-1 RNA-negative samples, gp140 reactivity decreased without affecting characterization of HIV-2 samples. CONCLUSIONS: With HIV-1 samples, Geenius, WB and MS performance was similar as supplemental tests. The updated Geenius software reduced false gp140 reactivity, but had no impact on identifying true HIV-2 infections. Further evaluation will assess the impact of the Geenius software update on final diagnostic interpretations.
BACKGROUND: In the US, the HIV diagnostic algorithm for laboratory settings recommends the use of an HIV-1/HIV-2 differentiation supplemental assay after an initial reactive antigen/antibody (Ag/Ab) assay result. Since the discontinuation of the Multispot HIV-1/HIV-2 Rapid Test (MS), the Geenius HIV-1/2 Supplemental assay (Geenius) is the only FDA-approved supplemental differentiation test. OBJECTIVE: We compared the performance of Geenius to MS and Western Blot (WB). STUDY DESIGN: The relative seroconversion plasma reactivity of Geenius and MS was assessed using a 50% cumulative frequency analysis from 17 HIV-1 seroconverters. In addition, previously characterized plasma specimens, 186 HIV-1 positive, 100 HIV-2 positive, and 93 Ag/Ab-positive/HIV-1 RNA-negative, were tested with Geenius v1.1 software. McNemar's test was used for paired comparison analysis. A subset of 48 specimens were retested with the upgraded Geenius v1.3 software. RESULTS: In HIV-1 seroconverters, the relative seroconversion reactivity was 2.5 and 2 days before the first positive HIV-1 WB for Geenius and MS, respectively. In HIV-1 positive samples, Geenius performed similarly to HIV-1 WB (p=0.1687) and MS (p=0.8312). In HIV-2 positive samples, Geenius underperformed compared to HIV-2 WB (p=0.0005) and MS (p=0.0012). When using the upgraded software among the HIV-1 positive and Ag/Ab-reactive/HIV-1 RNA-negative samples, gp140 reactivity decreased without affecting characterization of HIV-2 samples. CONCLUSIONS: With HIV-1 samples, Geenius, WB and MS performance was similar as supplemental tests. The updated Geenius software reduced false gp140 reactivity, but had no impact on identifying true HIV-2 infections. Further evaluation will assess the impact of the Geenius software update on final diagnostic interpretations.
Authors: Dana Duncan; John Duncan; Bastian Kramer; Alex Y Nilsson; Betiel Haile; Ann Butcher; Shikha Chugh; Paul Baum; Grace M Aldrovandi; Stephen Young; Ann K Avery; Karen Tashima; Alexandra Valsamakis; Joseph D Yao; Ming Chang; Robert W Coombs Journal: J Clin Microbiol Date: 2021-06-18 Impact factor: 5.948
Authors: Marc A Pitasi; Shilpa N Patel; Laura G Wesolowski; Silvina Masciotra; Wei Luo; S Michele Owen; Kevin P Delaney Journal: Sex Transm Dis Date: 2020-05 Impact factor: 3.868