CROI 2017 Abstract e-Book

Abstract eBook

Poster and Themed Discussion Abstracts

1 Stellenbosch Univ, Cape Town, South Africa, 2 Univ of Pittsburgh, Pittsburgh, PA, USA, 3 Stellenbosch Univ, Parow, South Africa Background: Early ART initiation in infants reduces the number of HIV infected cells and may delay viral rebound after ART interruption. It is unknown whether the few HIV infected cells that persist on long-term ART harbor proviruses capable of virion production. This study was undertaken to evaluate how often HIV is inducible from CD4+ T lymphocytes in early ART treated children. Methods: Stored PBMC samples were analyzed from Post-CHER participants who began ART at <1 year of age and sustained suppression of viremia through to time of sampling at age 7-8. Total HIV-1 DNA in PBMC was quantified by qPCR targeting a conserved region in integrase. Total inducible virus recovery (TVR) assays were performed on purified CD4+ T cells stimulated with PMA and ionomycin for 7 days. Virus outgrowth assays (VOA) were also performed with purified CD4+ T cells, activated with phytohemagglutinin and co- cultured for 28 days with irradiated HIV-1 negative feeder cells and CD8-depleted blasts. Depending on CD4+ T cell recovery, replicas of 1x10[6] CD4+ T cells were seeded for both assays. Supernatants were collected on day 8 for the TVR assay and days 7, 14, 21 and 28 for VOA. HIV-1 RNA was measured in cell culture supernatants using a quantitative HIV-1 PCR assay targeting integrase (iSCA) with single-copy sensitivity. VOA supernatants were also assayed for p24 antigen by EIA. Results: Samples from 10 children (6 females, 4 males) were studied (median ART initiation age: 6 months) after 7-8 years of viremia suppression. Five participants had pre-ART HIV RNA >750,000 copies/ml and 5 had a median pre-ART HIV RNA of 635,000 copies/ml. The median CD4 percentage at the age of 7-8 years was 39%. Median cell associated HIV-1 DNA was 38 copies per million cells (range: 4.5-186). Two of 10 children had inducible HIV-1 RNA by TVR assay detected by iSCA at 2267 and 24 copies/ml, respectively. All VOA supernatants collected were negative for p24 antigen, but 4 participants had detectable HIV-1 RNA at day 21 (range: 9-697 copies/ml). No-RT controls excluded HIV-1 DNA contamination. Conclusion: Children initiated on ART early did not have infectious virus that could be readily isolated in viral outgrowth assays. However, inducible virion production was detected in 4 of 10 children using a highly sensitive HIV-1 RNA assay. This assay may be a sensitive biomarker for virion production in latent HIV reservoirs from children fromwhom only small sample volumes are feasible. 796 HIV RESERVOIR SIZE IS NOT INCREASED BY SHORT ART INTERRUPTION IN KENYAN INFANTS Mark D. Pankau 1 , Dalton Wamalwa 2 , Sarah Benki-Nugent 3 , Agnes Langat 4 , Ken Tapia 3 , Elizabeth Maleche-Obimbo 5 , Julie Overbaugh 1 , Grace John-Stewart 3 , Dara Lehman 1 1 FRCHC, Seattle, WA, USA, 2 Univ of Nairobi, Nairobi, Kenya, 3 Univ of Washington, Seattle, WA, USA, 4 US CDC, Nairobi, Kenya, 5 Kenyatta Natl Hosp, Nairobi, Kenya Background: ART initiation during primary HIV infection limits the size of the latent reservoir. Interventions following early antiretroviral treatment (ART) are currently being tested to optimize post-treatment control. Evaluating these approaches will require treatment interruption, which may lead to viral rebound and an increased latent reservoir size, decreasing the benefits of early ART. Here we assess the impact of short ART interruption on HIV reservoir size in a cohort of early ART treated infants. Methods: The Optimizing Pediatric HIV-1 Treatment study (NCT00428116) was a randomized trial comparing outcomes of Kenyan infants randomized to treatment interruption or continued therapy after ART for 24 months. Infants with CD4 >25% and normal growth characteristics were eligible for randomization. In the ART interruption arm, treatment was resumed if CD4 fell below 25%. Infants who suppressed virus levels during the first 24 months of ART, with at most 1 viral blip >1000c/mL after initial viral suppression, were included in this sub study. Infant reservoir size was quantified by ddPCR for total HIV DNA using cross-subtype pol primers at 24 months post ART initiation, and again 18 months later, following randomization to treatment interruption (n=7) or continued ART (n=7). Change in HIV DNA reservoir size was compared by Wilcoxon Rank sum test in infants with and without treatment interruption. Results: Among 14 infants evaluated, median age at ART initiation was 4.8 months and age at randomization was 28.9 months. Infants randomized to continued ART had a median of 168 copies of HIV DNA/1e6 PBMCs (IQR: 100-235) at 24 months after ART initiation and a median of 50 copies of HIV DNA/1e6 PBMCs (IQR: 24-173) 18 months later. Infants randomized to treatment interruption had a median of 90 copies of HIV DNA/1e6 PBMCs (IQR: 54-485) at 24 months after ART initiation and 184 (IQR:92-280) copies HIV DNA/1e6 PBMCs 18 months after ART interruption. When HIV DNA for each infant was compared between 24 months after ART initiation and 18 months later, the median HIV DNA fold change in infants who continued ART was 0.23 (IQR: 0.15-0.51), while the median HIV DNA fold change in infants undergoing a median of 106 days of treatment interruption was 1.04 (IQR: 0.71-1.6) (p=0.073). Conclusion: Our data suggest that while the latent reservoir decayed during continuous ART, short treatment interruption did not cause a large increase in the size of the latent reservoir. 797 HIV SUBTYPE D IS ASSOCIATED WITH INCREASED LATENT RESERVOIR SIZE IN CHILDREN Leila B. Giron 1 , Jane Achan 2 , Paul Bangirana 3 , Moses R. Kamya 3 , Diane V. Havlir 4 , Joseph K. Wong 4 , Theodore Ruel 4 , Satish K. Pillai 5 1 Fed Univ of Sao Paulo/Blood Systems Rsr Inst, Sao Paulo, Brazil, 2 Disease Control and Elimination Theme, Med Rsr Unit, Fajara, Gambia, 3 Makerere Univ, Kampala, Uganda, 4 Univ of San Francisco, San Francisco, USA, 5 Blood Systems Rsr Inst/UCSF, San Francisco, CA, USA Background: Antiretroviral therapy (ART) has dramatically improved the survival of children with HIV infection. However, ART does not achieve viral eradication, due to the presence of integrated provirus in resting CD4+ T lymphocytes. This population of potentially long-lived, persistently-infected cells, often called the latent HIV reservoir, is the barrier to achieving HIV eradication. Although HIV subtype has been associated with virulence, replication capacity, and cognitive impairment in infected individuals, it is unclear if HIV subtype influences the size of the latent HIV reservoir in children on ART. Methods: Peripheral blood mononuclear cell (PBMC) samples were collected from HIV-infected children enrolled in PROMOTE-pediatrics (NCT00978068) trial, in which children were randomized to receive either lopinavir or NNRTI-based ART. Samples were collected ~ 500 days after ART start. HIV-subtype was determined by population sequencing of the pol HIV DNA region, followed by application of the REGA and Recombinant Identification Program algorithms. Surrogates of HIV reservoir size (levels of total cell-associated HIV DNA and RNA) were measured using quantitative real time PCR. We compared reservoir size between subtype A and subtype D HIV-infected, ART-suppressed children using Mann-Whitney tests. Results: The subtype distribution of 126 samples was: A:78, D:27, C:4, A1D:2; subtype indeterminate: 15. There was no difference in treatment assignment between subtypes. Among the 105 with subtype A or D, the mean age at time of sampling was 7.3 years, mean duration of ART was 566 days, and there were no differences in CD4+ count; 21 had detectable plasma HIV RNA at the time of sampling and were excluded. Subtype D-infected children had significantly higher levels of total HIV DNA (mean 390 copies/106cells) compared to subtype A-infected children (mean 291 copies/106cells; p=0.03). No difference was observed in cell-associated HIV RNA between the two groups. HIV RNA/DNA ratio (transcriptional ratio) approached statistical significance with higher mean in subtype A-infected children (mean 1.1) as compared to subtype D-infected children (mean 0.7; p=0.09). Conclusion: Children infected with HIV subtype D had increased latent HIV reservoir size compared to subtype A. These observations suggest that subtype associated genetic variation may impact HIV persistence, and should be carefully considered in future studies targeting the latent reservoir of HIV in children. 798 B-CELL RESPONSES IN EARLY TREATED LONG TERM VIRAL SUPPRESSED SERONEG HIV+ CHILDREN Paolo Palma 1 , Paola Zangari 1 , Nicola Cotugno 2 , Eleni Nastouli 3 , Laura McCoy 4 , Salvatore Rocca 2 , Bridget Ferns 3 , Savita Pahwa 5 , Paolo Rossi 1 , for the EPIICAL Consortium 1 Children’s Hosp Bambino Gesù, Rome, Italy, 2 Univ of Rome Tor Vergata, Rome, Italy, 3 Univ Coll London Hosps NHS Trust, London, UK, 4 Univ Coll London, London, UK, 5 Univ of Miami, Miami, FL, USA Background: The paucity of HIV specific immune responses in early treated HIV-infected (treated within 6 months of age; ET) children could represent an important limitation in the perspective of immune therapeutic studies. In ET, the failure to develop an immune response is attributed to the lack of Ag stimulation, possibly indicating shrinking HIV reservoirs. Analysis of HIV Ab can provide important insight in order to characterize host–immune profiles associated to HIV remission which appears to be associated with

Poster and Themed Discussion Abstracts

CROI 2017 345