CROI 2017 Abstract e-Book

Abstract eBook

Poster and Themed Discussion Abstracts

Results: HIV+ kidney or liver transplant recipients of both HIV+ and HIV- donors on ART were enrolled (n=17). Induced HIV-1 mRNA was detectable in all 10 samples tested. IPPMs ranged from 0.858-42.620 with a mean of 16.819. For patients with longitudinal measurements to date (n=5), all had an increase in IPPM at week 13 post-transplant compared to pre-transplant (p=0.008) with a maximum 10-fold increase in one patient. Conclusion: We designed a novel assay to measure the inducible LR with a high dynamic range and specificity. Preliminary results demonstrated an increase in the inducible HIV-1 LR post-transplant, which could represent clonal expansion of infected cells, due to compensatory lymphocyte proliferation after immune cell depletion and/or heightened immune activation during transplant. This finding may have implications for HIV-1 cure strategies in these patients. 318 PERSISTENCE OF A MINORITY HIV VARIANT DESPITE ALLOBMT WITH COMPLETE DONOR CHIMERISM Adam Capoferri 1 , Andrew D. Redd 2 , Daniel I. Rosenbloom 3 , Roberto Ramirez 1 , Subul Beg 1 , Andrew Timmons 4 , Christopher Gocke 1 , Robert Siliciano 1 , Richard Ambinder 1 , Christine Durand 1 1 The Johns Hopkins Univ, Baltimore, MD, USA, 2 NIAID, Bethesda, MD, USA, 3 Columbia Univ, New York, NY, USA, 4 Johns Hopkins Hosp, Baltimore, MD, USA Background: Continuous antiretroviral therapy (ART) with allogeneic bone marrow transplant (alloBMT) is being investigated as an HIV eradication strategy. After alloBMT, the disappearance of the HIV latent reservoir (LR) was initially observed in two reported “Boston patients”; however, with analytical ART interruption there was viral rebound from an unknown source. In a pilot clinical trial of optimized ART and alloBMT for HIV-infected patients, we present evidence of HIV persistence despite full donor chimerism.

Methods: The HIV LR was measured pre-alloBMT and every 12 weeks after with a quantitative viral outgrowth assay (qVOA), digital droplet PCR (ddPCR) with pol primers, and quantitative PCR using gag primers in peripheral blood mononuclear cells (PBMCs). The pol region from positive qVOA supernatant RNA and proviral DNA from PBMCs was sequenced (Sanger method). Sequences were aligned and phylogenetic analysis performed using a neighbor-joining tree. Chimerism from PBMCs was determined using microsatellites or short tandem repeats to distinguish donor from recipient (ABI, AmpflSTR, limit of detection 1%). Results: The patient had chronic HIV infection on ART with relapsed Hodgkin Lymphoma and underwent a reduced-intensity haploidentical alloBMT. Week 8 post alloBMT, he had full donor chimerism in peripheral blood. By qVOA, the LR decreased from 2.76 IUPM at baseline to undetectable levels at weeks 12, 24, 36 and 52. Proviral DNA by both ddPCR and qPCR demonstrated a 1 log increase at week 8, clinically at this time the patient had CMV reactivation and suspected histoplasmosis infection. Phylogenetic analysis suggested that at baseline the patient had dual infection with two distinct viral variants. Week 8 proviral DNA was identical to a replication competent minority variant isolated in the qVOA pre- alloBMT. At week 64, the LR was detected by qVOA (0.03). The pol region of week 64 qVOA virus was identical to the pre-alloBMT minority variant and week 8 proviral DNA sequence.

Poster and Themed Discussion Abstracts

Conclusion: In a patient who achieved full donor chimerism post-alloBMT, we were able to detect HIV persistence both by ddPCR and qPCR at week 8, and by viral outgrowth from resting memory CD4+ T cells at 64 weeks post-transplant. More sensitive studies of chimerism are needed to determine if this represents de novo infection of donor cells or persistence and/or clonal expansion of rare host cells. 319 TWO HUNDRED EIGHTY-EIGHT–DAY DRUG-FREE REMISSION FROM HIV REBOUND BY ALLOGENEIC PBSCT Nathan Cummins 1 , Stacey Rizza 1 , Jason Baker 2 , Nicolas Chomont 3 , Tae-Wook Chun 4 , Mathias Lichterfeld 5 , Douglas D. Richman 6 , Timothy Schacker 7 , Joseph D. Yao 1 , Andrew Badley 1 1 Mayo Clinic, Rochester, MN, USA, 2 Univ of Minnesota, Minneapolis, MN, USA, 3 Univ de Montréal, Montreal, QC, Canada, 4 NIH, Bethesda, MD, USA, 5 Massachusetts General Hosp, Boston, MA, USA, 6 Univ of California San Diego, La Jolla, CA, USA, 7 Univ of Minnesota, Minneapolis, MN, USA Background: As HIV cure strategies are tested a reliable measure of cure is needed to predict drug-free remission from viral rebound. We evaluated HIV reservoir size through the post-transplant period in a patient with HIV who underwent allogeneic peripheral blood stem cell transplant (PBSCT) for acute lymphoblastic leukemia. An antiretroviral Analytic Treatment Interruption was initiated after 2 years. Methods: PBMCs were obtained by leukapheresis for HIV reservoir size estimation. Plasma was tested with Amplicor HIV-1 DNA Test, v1.5. Total HIV DNA in CD4 T cells was measured by qPCR and digital droplet PCR separately. Integrated HIV DNA in CD4 T cell subsets was measured by Alu-nested PCR. The frequency of CD4 T cells with replication competent virus was determined by quantitative viral outgrowth assay. Results: A 55 y.o. man with ART suppressed HIV-1 was seen at Mayo Clinic for B-cell ALL. He underwent allogeneic reduced-intensity conditioning PBSCT with an HLA- and ABO- matched sibling as donor, with tacrolimus and methotrexate for GVHD prophylaxis. Both donor and recipient were CCR5 wild-type. His course was notable for mild GVHD in colon (biopsy confirmed) and Pneumocystis jiroveci pneumonia. As of this report the ALL is in complete remission. ART was continued through the peri-transplant period, and plasma HIV-1 RNA and proviral DNA became undetectable by clinical assays. In situ hybridization for HIV in GI lymphatic tissue (colon) was negative. Table below presents results from HIV reservoir assessments. Total and integrated HIV DNA and replication competent virus in peripheral CD4 T cells decreased post-transplant to undetectable or near undetectable levels. At 784 days post PBSCT, given multiple negative tests for HIV and de-evolving western blot for antibodies to HIV, he initiated ATI of all ART. Plasma viremia was measured weekly for 8 weeks, then monthly, and remained undetectable (LLD 10 copies/ml) for 9 months post-ATI. On ATI day 288 his plasma HIV RNA level became detectable at 48 copies/ ml, increased to 283 (ATI day 289), and then 1640 (ATI day 293), prompting reinitiation of ART. Conclusion: Our case illustrates that PBSCT with ART can significantly reduce HIV reservoir size, and enable prolonged drug free remission from HIV rebound. It is unclear why in the absence of cure, HIV rebound was profoundly delayed at 288 days post ATI. Functional analyses are underway to identify immune mechanisms which may have delayed HIV rebound.

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