CROI 2016 Abstract eBook

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Poster Abstracts

Methods: The integrase coding region was sequenced using an in-house nested-PCR protocol in both integrase inhibitor (INI) naïve and experienced HIV-2 viremic patients. Mutations associated to RAL and DGV resistance in HIV-1 were characterized. Plasma HIV-2 RNA changes were measured following DGV introduction in a subset of patients with RAL failure. Results: From a total of 319 HIV-2 patients recorded at the HIV-2 Spanish cohort up to September 2015, a total of 52 integrase sequences from 30 patients had been obtained (21 RAL-naïve and 9 RAL-experienced). Only two secondary mutations (E138A and Q148E) were found in two out 21 RAL-naïve patients. The resistance mutation profile in 8 out of 9 viremic patients with RAL failure was: A153G+N155H (3); E92Q+T97A+N155H (1); G140S+Q148R (1); G140A+Q148R (1); T97A+A119T+Y143G+A153S (2) and T97A+Y143C (1). Five of these 8 patients were subsequently rescued with DGV. One patient harbouring N155H+E92Q+T97A regained and has kept on sustained viral suppression for 34 months of DGV, accompanied with large CD4 gains (from 124 to 270 cells/μl). Another patient harbouring T97A+Y143G+A153S achieved viral suppression along with CD4 gains from 86 to 308 cells/μl. However, one patient with multidrug resistance harbouring N155H+A153G experienced 1 log drop in HIV-2 RNA along with CD4 gains from 16 to 147 cells/μl, but subsequently experienced virological failure and CD4 drop to 54 cells/μl selecting V151I. This is the first report of DGV resistance in HIV-2. Data on the remaining two patients (both subtype B clades) and N115H+A153G and Y143C+T97A will be presented since they are still on too early follow-up. Conclusions: There is a wide repertoire of resistance mutations at the integrase in HIV-2 patients failing on RAL. Although DGV may allow successful rescue in most HIV-2 RAL failures, we report and characterize the first case of resistance to DGV in one HIV-2 patient. 509 Prevalence of Minority Resistant Variants in HIV-2 Naïve Patients: ANRS CO5 Cohort Alexandre Storto 1 ; BenoitVisseaux 2 ; Gilles Collin 1 ; Catherine Fagard 3 ; Marine Naudin 3 ; Florence Damond 1 ; Marie-Aude Khuong 4 ; Sophie Matheron 1 ; Diane Descamps 5 ; Charlotte Charpentier 2 1 Hosp Bichat-Claude Bernard, Paris, France; 2 INSERM UMR 1137, Paris, France; 3 CMG-EC INSERM U897, Bordeaux, France; 4 Hosp Delafontaine, Paris, France; 5 Hosp Bichat-Claude Bernard, Päris, France Background: To assess the prevalence of minority resistant variants (MRV) and X4-minority variants in antiretroviral-naïve HIV-2-infected patients included in the French HIV-2 Cohort (ANRS CO5). Methods: Antiretroviral-naïve HIV-2-infected patients with detectable plasma viral load (VL) (>100 c/mL) were assessed. We performed UltraDeep Sequencing (UDS) (Roche 454 ® Life Sciences) in protease (PR) and reverse transcriptase (RT) regions issued from plasma viruses. Only mutations >1%were considered and interpreted with HIV-2 ANRS list (Charpentier et al., 2015). HIV-2 tropismwas assessed by UDS of V3 loop region. Tropism of each sequence read was interpreted with HIV-2 major determinants of CXCR4 co- receptor use (L18X, V19K/R, V3 global net charge, insertions at position 24). Results: 47 patients were assessed (median age: 48 years [IQR=36-57], 61%women, 68% originating fromWest Africa , 12% at CDC-C stage). At time of sampling, median CD4 cell count was 326/mm 3 (IQR=215-438) and median VL was 2130 c/mL (IQR=816-4495). 67% of patients were infected with HIV-2 group A and 33%with group B. Protease and RT UDS was successful in 41 (87%) and 38 (81%) samples, respectively. Prevalence of virus with PR or RT drug resistance mutations (DRM) using 1% and 20% detection threshold was 17.1% (95%CI=5.5-28.7) and 7.3% (95%CI=0.0-15.4), respectively. DRM detected at the 20% detection threshold were M184V in one case and N69S in two cases. MRV exhibiting at least 1 NRTI DRM were detected in 1 patient (2.6%, 95%CI=0.0-6.8), showing the mutation N69S in a proportion of 1.4%. MRV exhibiting at least 1 PI DRM were detected in 4 patients (9.8%, 95%CI=0.7-18.9): (i) two I50V-mutated MRV (1.6% and 1.0%); (ii) one V47A (1.0%); and (iii) one with both I50V and I54L (1.2% and 1.1%, respectively). Tropism was assessed in 19 samples (mean number of reads=7591) showing 2 samples (11%) exhibiting X4-tropic viruses in more than 50% of the reads. Among the 17 remaining samples, X4-minority variants were detected in 11 (65%) in a median proportion of 0.41% (IQR=0.33-0.76). Conclusions: In this first study assessing the prevalence of MRV in HIV-2 infection, we observed a two to three-fold higher prevalence of DRM in antiretroviral-naive patients when 1% detection threshold of mutations was used compared to 20% threshold. In addition, X4-minority variants were detected in the majority of patients. 510 Evaluation of an EIA-Based Testing AlgorithmUsing Dried Blood Spots From South Sudan Idris Hakim 1 ; Hetal Patel 2 ;Yen Duong 2 ; Joel Katoro 3 ; GregoryWani 1 ; Idris Farouk 1 ; Alex Bolo 3 ; Avi Hakim 2 ; Bharat Parekh 2 1 Ministry of Hlth, Juba, South Sudan; 2 CDC, Atlanta, GA, USA; 3 CDC, Juba, South Sudan Background: Due to high sensitivity of enzyme immunoassays (EIA) some level of false positivity is expected when used alone or in an EIA-based testing algorithm for HIV diagnostic testing. This is problematic for antenatal clinic (ANC) surveys whose data are used for surveillance purposes as it can lead to inflated prevalence estimates. DBS are preferred specimen for HIV surveillance surveys as they are simple, inexpensive, and can be prepared in non-laboratory settings. However, use of DBS specimens requires modification and optimization of EIA procedures. We present results from an EIA testing algorithm compared to the US Centers for Disease Control (CDC) external quality assurance (EQA) testing algorithm applied to specimens from the South Sudan 2012 ANC survey. Methods: DBS specimens collected for the South Sudan 2012 HIV ANC Survey were tested at the Juba Teaching Hospital Laboratory. Of the 11,155 specimens collected in the ANC survey, 1059 HIV-negative and 285 HIV-positive specimens were sent to CDC Atlanta for EQA testing. As part of the South Sudan testing algorithm, the specimens were screened on Vironostika Uni-form II plus EIA (Biomerieux, France) and reactives were confirmed by Murex HIV-1.2.O EIA (Abbott, Germany). Retesting at CDC was performed using an optimized DBS elution protocol on Genetic Systems HIV-1/2 plus O (GS 1-2-O, Bio-Rad, California) followed by confirmation of positives on Cambridge Biotech HIV-1 Western Blot (WB) (Maxim Biomedical, Maryland). Specimens with discrepant final classification between the two algorithms were further confirmed by WB. Results: Of the 1344 of specimens tested, the overall agreement of the South Sudan and CDC algorithms was 97.5%; however, 97.2% and 89.1% agreements were observed amongst the negatives and positives, respectively. A total of 33 specimens (2.5%) were discrepant between the algorithms and of those, 29 (88%) specimens were negative and 4 (12%) specimens were indeterminate according to WB results. The optical density values of most false positive (FP) specimens were low on EIAs indicating inherent false positivity of EIAs that is magnified when DBS specimens are used. Conclusions: Our result suggests a high FP rate with EIA-testing algorithm alone. These results highlight the need to incorporate a more specific assay such as WB or similar test in the testing algorithm to confirm the HIV status and ensure the accuracy of HIV prevalence data. Use of DBS specimens requires additional optimization steps to ensure accurate results. 511 Comparison of Cross-Sectional Incidence Assay Results From DBS and Plasma Katherine Schlusser 1 ; Christopher Pilcher 2 ; Esper G. Kallas 3 ; Breno R. Santos 4 ; Steven G. Deeks 2 ; Sheila M. Keating 5 ; Shelley Facente 2 ; Susan H. Eshleman 6 ;Thomas C. Quinn 6 ; Oliver Laeyendecker 7 ; for the Consortium for the Evaluation and Performance of HIV Incidence Assays (CEPHIA) 1 Johns Hopkins Univ, Baltimore, MD, USA; 2 Univ of California San Francisco, San Francisco, CA, USA; 3 Univ of Sao Paulo Med Sch, Sao Paulo, Brazil; 4 Hosp Conceição, Porto Alegre, Brazil; 5 Blood Systems Rsr Inst, San Francisco, CA, USA; 6 Johns Hopkins Univ Sch of Med, Baltimore, MD, USA; 7 NIH, Bethesda, MD, USA Background: Assays have been developed for cross-sectional HIV incidence estimation using plasma samples. Large scale surveillance programs are planned using dried blood spot (DBS) specimens for incidence assessment. However, limited information exists on the performance of HIV cross-sectional incidence assays using DBS. This study compared results obtained from three incidence assays using plasma and DBS samples. Methods: The assays evaluated were: Maxim HIV-1 Limiting Antigen Avidity EIA (LAg-Avidity), Sedia HIV-1 BED-Capture EIA (BED-CEIA), and CDC optimized BioRad HIV-1/2 Plus O Avidity-based Assay (BioRad Avidity) using pre-determined cutoff values. 100 matched HIV-1 positive plasma and DBS samples, with known duration of infection, from the

Poster Abstracts

197

CROI 2016