CROI 2017 Abstract e-Book

Abstract eBook

Poster and Themed Discussion Abstracts

235

SOLUBLE UPAR PREDICTS ALL-CAUSE MORTALITY FROM HIV-1 INFECTION Ditte M Kirkegaard-Klitbo, Anne Langkilde, Niels Mejer, Ove Andersen, Jesper Eugen-Olsen, Thomas Benfield Hvidovre Hosp, Hvidovre, Denmark Background: Persistent inflammation and immune activation have been associated with mortality and non-AIDS comorbidity in HIV infection. The urokinase plasminogen activator receptor is involved in numerous processes including recruitment of leucocytes from the circulation to inflammatory sites. Here we investigated if inflammation measured by soluble urokinase plasminogen activator receptor (suPAR) was associated with incident non-AIDS comorbidity and all-cause mortality in HIV-1 infection. Methods: Prospective single-center cohort study (n = 945). Plasma suPAR was quantified in HIV-1 infected individuals on antiretroviral treatment (ART) by ELISA at study entry in 2007. Associations between baseline plasma levels of suPAR and all-cause mortality and non-AIDS comorbidity were conducted by Cox regression analysis adjusted for pertinent covariates. Non-AIDS comorbidity was ascertained by registry linkage.

Results: At baseline, median age of study participants were 45 years, 73%were men, 78% were white. During a median of 7.9 years of follow up, 119 (13%) deaths occurred. Baseline median suPAR level was higher in non-survivors compared to survivors (4.03 ng/mL (IQR: 2.80-5.58) versus 2.56 ng/mL (IQR: 2.04-3.26), p < 0.001) respectively. In multivariate Cox regression analyzes, each ng/mL higher suPAR level was associated with a 42% increased risk of death (aHR (95% CI): 1.42 (1.30; 1.54), p<0.001). Highest quartile of plasma suPAR was associated with a more than 6 fold increased risk of death compared to the lowest quartile (aHR (95% CI): 6.70 (3.28; 13.70), p<0.001). Baseline median suPAR level was higher in patients with known comorbidity at baseline compared to patients without comorbidity (3.02 ng/mL (IQR: 2.33-4.11) versus 2.58 (IQR: 2.05-3.35) respectively). With baseline non-AIDS comorbidity excluded, no significant association was found between plasma levels of suPAR and diagnosis of non-AIDS comorbidity (defined as (n): cancer (70), diabetes mellitus (35), cardiovascular disease (75), chronic lung disease (57), liver disease (24) or chronic kidney disease (23)) during follow up. Conclusion: Plasma suPAR levels were an independent marker of all-cause mortality but not incident non-AIDS comorbidity in HIV-1 infected individuals.   236 R5-TROPIC HIV RESISTANCE IN A SUBSET OF ELITE AND VIREMIC CONTROLLERS Elena Gonzalo-GIL, Patrick Rapuano, Jimmy Auer, Zach Porterfield, Uchenna Ikediobi, Ayse Coskun, Richard Sutton Yale Univ, New Haven, CT, USA Background: Elite and Viremic Controllers (EC/VCs) appear to have an intrinsic ability to control HIV infection, perhaps because of host genetic determinants. Our aim is to identify EC/VCs with intrinsic resistance to HIV in vitro and to perform cell-based and genetic studies to determine if there is an associated hereditary basis. Methods: Samples from ECs/VCs (n=154) were obtained from UCSF, Ragon, VA Medical Centers and IBIS using standard EC/VC criteria. CD4+ T cells purified from PBMCs were activated by anti-CD3/CD28 and infected with replication-defective HIV with different tropisms (R5, X4, and VSVG). Infection rate was analyzed after 3 days by flow cytometry as %YFP+ transduced cells and results were compared with healthy donors (CTRL) (n=25) and progressors on therapy (prog) (n=11). CCR5 and CCR2 surface levels and RNA expression levels were analyzed by flow and qPCR, respectively. MIP1-α and -β were analyzed by ELISA. CD4+ T cells from 2 EC family members were obtained, activated, and infected, and CCR5 and CCR2 expression levels analyzed. Statistical differences were tested by Mann-Whitney U-test or ANOVA using GraphPad Prism. P <0.05 were considered significant. Results: For most controls and EC/VCs, there was no resistance to either VSV-G, X4-, or R5-tropic pseudotyped particle infection in activated CD4+ T cells. However, 16% of EC/ VCs (24/154) showed 4-fold resistance, on average, specific to R5-tropic virus (%YFP+ EC/VCs 0.41±0.29 vs CTRL 1.35±0.51 and prog 1.54±0.48; P=0.001). CD4+ T cells from EC/ VCs with R5 resistance were more susceptible to R5-tropic virus infection after overexpression of CCR5 using a lentiviral vector. Decreased CCR2 and CCR5 RNA levels (5-fold and 8-fold, respectively) in EC/VCs with R5 resistance phenotype were observed compared to CTRL and prog (P<0.0001). CCR2 and CCR5 levels (RNA and protein) were highly correlated (r=0.93; P<0.0001). Decreased levels of MIP1-α and -β in EC/VCs with R5 resistance were observed compared to CTRL (P<0.05). Resistance specific to R5 virus was observed in some EC/VC family members (3 of 7 analyzed) and also correlated with decreased CCR2 and CCR5 RNA and cell surface levels. Conclusion: Resistance specific to R5 HIV was observed in some family members of the index EC with the same phenotype, and was associated with CCR2 and CCR5 down- regulation, suggesting a common regulatory mechanism. Further studies should help pinpoint whether the down-regulation is transcriptional or post-transcriptional in nature. 237LB MULTI-ANCESTRY GWAS IDENTIFIES NOVEL VARIANTS ASSOCIATED WITH HIV-1 VIRAL LOAD Eric O. Johnson 1 , Dana B. Hancock 1 , Nathan C. Gaddis 1 , Christina A Markunas 1 , Yuelong Guo 1 , Elizabeth T. Golub 2 , Mardge H. Cohen 3 , Kathryn Anastos 4 , Ruth Greenblatt 5 , Bradley E. Aouizerat 6 1 RTI Intl, Rsr Triangle Park, NC, USA, 2 Johns Hopkins Univ, Baltimore, MD, USA, 3 Stroger Hosp, Chicago, IL, USA, 4 Albert Einstein Coll of Med, Bronx, NY, USA, 5 Univ of California San Francisco, San Francisco, CA, USA, 6 New York Univ, New York, NY, USA Background: HIV viral load (VL) is a predictor of time until HIV progression, a key measure of risk and treatment response, and a critical focal point for research. Prior genome- wide association studies (GWAS) of VL set-point (VLSP) in European-descent samples found replicable variant associations in the HLA gene region. We conducted the first multi- ancestry GWAS of VLSP, followed by RNA expression quantitative trait loci (eQTL) analyses to assess putative function of nominated variants. Methods: Discovery analyses used 20 million 1000 Genomes imputed SNPs and indels among 705 African Americans (AAs), 215 European Americans (EAs), and 110 Hispanic HIV+ participants from the Women’s Interagency HIV Study. Replication was tested in the Urban Health Study: 531 AAs and 258 EAs. We assessed potential function of variants as cis- eQTLs using data from the Genotype-Tissue Expression project v6, with replication tested in GEUVADIS. Results: One peak was identified at p<5.0×10 -8 on chromosome 6 within the HLA-B gene. The 44 genome-wide significant follow-up variants constituted 14 independent tests: multiple testing p-value <0.0036. Eighteen variant associations were replicated: rs146647111 was the top replication variant (discovery P = 4.7×10 -16 ; replication P = 5.3×10 -5 ). Rs146647111 remained associated with VLSP after adjusting for all 8 known VL associated SNPs and two independently associated classical HLA-B and HLA-A alleles, with only a modest reduction in effect size: before adjusting β = -0.53, P=2.4×10 -18 ; after adjusting β = -0.51, P=5.0×10 -6 . We tested rs146647111 (an intronic indel) as an eQTL for all genes within 1 Mb. The most significant association was with MICB (P=9.9×10 -18 ), which replicated in the independent sample (P=9.5×10 -7 ). MICB gene expression decreased in the presence of the minor, VLSP-protective AC allele. MICB encodes for a natural killer (NK) group 2 D (NKG2D) cell surface receptor ligand, which may be involved in the escape of HIV from NK cell-mediated cell death. Conclusion: The rs146647111–VLSP association observed across multiple ancestries is novel and independent of known variants associated with VL phenotypes. The observed effect of the rs146647111-AC allele on MICB expression suggests a biologically plausible pathway for this association: lower expression of MICB reducing capacity for HIV escape from NK cell mediated cell death.

Poster and Themed Discussion Abstracts

92

CROI 2017