Jean-Guy Baril

High Rates of Forward Transmission Events after Acute/Early HIV-1 Infection

BACKGROUND A population-based phylogenetic approach was used to characterize human immunodeficiency virus (HIV)-transmission dynamics in Quebec. METHODS HIV-1 pol sequences included primary HIV infections (PHIs; <6 months after seroconversion) from the Quebec PHI cohort (1998-2005; n=215) and the provincial genotyping program (2001-2005; n=481). Phylogenetic analysis determined sequence interrelationships among unique PHIs (n=593) and infections from untreated (n=135) and treated (n=660) chronically infected (CI) potential transmitter populations (2001-2005). Clinical features, risk factors, and drug resistance for clustered and nonclustered transmission events were ascertained. RESULTS Viruses from 49.4% (293/593) of PHIs cosegregated into 75 transmission chains with 2-17 transmissions/cluster. Half of the clusters included 2.7+/-0.8 (mean+/-SD) transmissions, whereas the remainder had 8.8+/-3.5 transmissions. Maximum periods for onward transmission in clusters were 15.2+/-9.5 months. Coclustering of untreated and treated CIs with PHIs were infrequent (6.2% and 4.8%, respectively). The ages, viremia, and risk factors were similar for clustered and nonclustered transmission events. Low prevalence of drug resistance in PHI supported amplified transmissions at early stages. CONCLUSIONS Early infection accounts for approximately half of onward transmissions in this urban North American study. Therapy at early stages of disease may prevent onward HIV transmission.

Valproic acid in association with highly active antiretroviral therapy for reducing systemic HIV‐1 reservoirs: results from a multicentre randomized clinical study

Conflicting results have been reported regarding the ability of valproic acid (VPA) to reduce the size of HIV reservoirs in patients receiving suppressive highly active antiretroviral therapy (HAART). In a randomized multicentre, cross‐over study, we assessed whether adding VPA to stable HAART could potentially reduce the size of the latent viral reservoir in CD4 T cells of chronically infected patients.

Virologic Failure Following Persistent Low-level Viremia in a Cohort of HIV-Positive Patients: Results From 12 Years of Observation

BACKGROUND The current goal of antiretroviral therapy (ART) is to maintain a suppressed human immunodeficiency virus (HIV) viral load below limits of assay detection. When viral loads remain in low-level viremia (LLV), especially between 50 and 200 copies/mL, the best management and clinical consequences remain unknown. Our objective was to study the long-term impact of persistent LLV on the subsequent risk of virologic failure in a cohort of people living with HIV in Montreal, Canada. METHODS We compared the cumulative incidence of subsequent virologic failure (defined as an HIV RNA viral load of >1000 copies/mL) in patients receiving ART for at least 12 months by following 4 persistence categories (<50, 50-199, 200-499, and 500-999 copies/mL) for 6, 9, or 12 months, using Kaplan-Meier analysis. The association between subsequent virologic failure and persistence status were estimated using a Cox proportional hazards model. RESULTS The cumulative incidence of virologic failure 1 year after having maintained a LLV for 6 months was 22.7% (95% confidence interval [CI], 14.9-33.6) for 50-199 copies/mL, 24.2% (95% CI, 14.5-38.6) for 200-499 copies/mL, and 58.9% (95% CI, 43.1-75.2) for 500-999 copies/mL, compared with 6.6% (95% CI, 5.3-8.2) for an undetectable HIV RNA viral load. Even after adjustment for potential confounders, a persistent LLV of 50-199 copies/mL for 6 months doubled the risk of virologic failure (hazard ratio, 2.22; 95% CI, 1.60-3.09), compared with undetectable viral loads for the same duration. Similar results have been found for persistent LLV of 9 or 12 months. CONCLUSIONS In this cohort, all categories of persistent LLV between 50 and 999 copies/mL were associated with an increased risk of virologic failure. The results shed new light for the management of patients with LLV, especially with regard to LLV of 50-199 copies/mL.

Association Between Tenofovir Exposure and Reduced Kidney Function in a Cohort of HIV-Positive Patients: Results From 10 Years of Follow-up

BACKGROUND Some studies have shown that tenofovir disoproxil fumarate (TDF), a drug widely used in highly active antiretroviral therapy, is associated with kidney dysfunction, but the magnitude of the effect and its clinical impact is still being debated. Our objective was to evaluate the association between long-term TDF exposure and kidney dysfunction in a cohort of 1043 human immunodeficiency virus-positive patients followed up for 10 years and to quantify the loss in estimated glomerular filtration rate (eGFR) in patients exposed to TDF in comparison with those exposed to other antiretroviral therapies. METHODS Adjusted hazard ratios (HR) and odds ratios (OR) for the association between TDF and kidney dysfunction (defined as eGFR <90 mL/min/1.73 m(2)) were calculated using the Cox proportional hazards model and generalized estimating equations. Mean loss in eGFR attributable to TDF by cumulative years of exposure was estimated using linear regressions. RESULTS Tenofovir exposure increased the risk of kidney dysfunction by 63% (HR, 1.63; 95% confidence interval, 1.26-2.10). The cumulative eGFR loss directly attributable to TDF after 1, 2, 3, and 4 years of TDF exposure was -3.05 (P = .017), -4.05 (P = .000), -2.42 (P = .023), and -3.09 mL/min/1.73 m(2) (P = .119), respectively, which shows that most of the loss occurred during the first years of exposure. CONCLUSIONS In this cohort, TDF exposure was associated with reduced kidney function, but the loss in eGFR attributable to TDF is relatively mild in a long-term perspective.

HIV-associated Lipodystrophy Syndrome: A Review of Clinical Aspects

Approximately two years after the introduction of highly active antiretroviral therapy for the treatment of HIV infection, body shape changes and metabolic abnormalities were increasingly observed. Initially, these were ascribed to protease inhibitors, but it is now clear that nucleoside reverse transcriptase inhibitors also contribute to lipodystrophy syndrome. The syndrome groups together clinical conditions describing changes in body fat distribution that include lipoatrophy, lipoaccumulation or both. However, there does not appear to be a direct link between lipoatrophy and lipoaccumulation that would support a single mechanism for the redistribution of body fat. Currently, there is no clear definition of lipodystrophy, which explains the difficulty in determining its prevalence and etiology. There are no current guidelines for the treatment of fat distribution abnormalities that occur in the absence of other metabolic complications. The present article reviews the current state of knowledge of the definition, symptoms, risk factors, pathogenesis, diagnosis and treatment of the morphological changes associated with lipodystrophy syndrome.

Immunosuppressive tryptophan catabolism and gut mucosal dysfunction following early HIV infection

BACKGROUND Tryptophan (Trp) catabolism into kynurenine (Kyn) contributes to immune dysfunction in chronic human immunodeficiency virus (HIV) infection. To better define the relationship between Trp catabolism, inflammation, gut mucosal dysfunction, and the role of early antiretroviral therapy (ART), we prospectively assessed patients early after they acquired HIV. METHODS Forty patients in the early phase of infection were longitudinally followed for 12 months after receiving a diagnosis of HIV infection; 24 were untreated, and 16 were receiving ART. Kyn/Trp ratio, regulatory T-cells (Tregs) frequency, T-cell activation, dendritic cell counts, and plasma levels of gut mucosal dysfunction markers intestinal-type fatty acid-binding protein, soluble suppression of tumorigenicity 2, and lipopolysaccharide were assessed. RESULTS Compared with healthy subjects, patients in the early phase of infection presented with elevated Kyn/Trp ratios, which further increased in untreated patients but normalized in ART recipients. Accordingly, in untreated subjects, the elevated Treg frequency observed at baseline continued to increase over time. The highest CD8(+) T-cell activation was observed during the early phase of infection and decreased in untreated patients, whereas activation normalized in ART recipients. The Kyn/Trp ratio was positively associated with CD8(+) T-cell activation and levels of inflammatory cytokines (interleukin 6, interferon γ-inducible protein 10, interleukin 18, and tumor necrosis factor α) and negatively associated with dendritic cell frequencies at baseline and in untreated patients. However, ART did not normalize plasma levels of gut mucosal dysfunction markers. CONCLUSIONS Early initiation of ART normalized enhanced Trp catabolism and immune activation but did not improve plasma levels of gut mucosal dysfunction markers.

Factors associated with a decrease in the prevalence of drug resistance in newly HIV-1 infected individuals in Montreal.

Objective: A decrease in the prevalence of drug resistance (DR) has been observed among recently infected (RI) individuals in Montreal. A study of chronically infected (CI) patients, who represent potential HIV-1 transmitters, was carried out in order to ascertain biological factors associated with this trend change. Design and methods: Retrospective analysis of CI patients was performed for the period 1996–2003. Changes in mean viral load and DR prevalence were assessed in CI patients (n = 2328) and compared to those in RI patients (n = 180) living in the same geographic area. Results: A decrease was observed in the prevalence of DR among RI patients, from 13.0% in 1997–2000 to 4.0% in 2001–2003 (P = 0.04). From 1996 to 2000, the mean viral load in the CI patients decreased by 1.34 log10, to remain steady thereafter. The proportion of CI patients who interrupt treatment increased steadily over 1997–2003 from 3.1% to 16.5% (P < 0.0001). Since 1999, when genotyping analysis became available, we have observed a 0.9 log10 decrease in mean viral load among 602 genotyped CI patients harbouring any major mutations. Conclusion: The decrease in transmission of DR documented in Montreal since 2000 coincides with the drop in mean viral load observed in CI patients. Factors that contribute to the decrease in viral load include routine access to genotyping and availability of more potent antiretroviral drugs. Plasma viral load seems to represent the main predictor for the transmission of DR.

Longitudinal Assessment of Changes in HIV-Specific Effector Activity in HIV-Infected Patients Starting Highly Active Antiretroviral Therapy in Primary Infection

Both the magnitude and breadth of HIV-specific immunity were evaluated longitudinally on samples collected from six subjects starting highly active antiretroviral therapy (HAART) preseroconversion (group 1), 11 recently infected subjects starting HAART postseroconversion (group 2), five subjects starting HAART in the second half of the first year of infection (group 3), and six persons starting treatment in the chronic phase of infection (group 4). HIV-specific immunity was measured by IFN-γ ELISPOT, detecting the frequency of cells responding to a panel of HLA-restricted HIV-1 peptides. Intracellular cytokine staining was used to detect the frequency of HIV-1 Gag p55-specific CD4+ and CD8+ T cells in a subset of participants. The magnitude and breadth of HIV-specific responses persisted in all group 1 subjects and in 5 of 11 (45%) group 2 subjects. Both of these parameters declined in 6 of 11 (55%) group 2 and in all group 3 and 4 individuals. All persons who maintained detectable numbers of HIV-1 Gag p55-specific CD4+ and CD8+ T cells after starting HAART preserved the intensity and breadth of their HIV-specific effector response. Our results show that HIV-specific immunity can be preserved even if HAART is initiated beyond the acute phase of infection.

Dual Therapy Treatment Strategies for the Management of Patients Infected with HIV: A Systematic Review of Current Evidence in ARV-Naive or ARV-Experienced, Virologically Suppressed Patients

Objective We reviewed the current literature regarding antiretroviral (ARV)-sparing therapy strategies to determine whether these novel regimens can be considered appropriate alternatives to standard regimens for the initial treatment of ARV-naive patients or as switch therapy for those patients with virologically suppressed HIV infection. Methods A search for studies related to HIV dual therapy published from January 2000 through April 2014 was performed using Biosis, Derwent Drug File, Embase, International Pharmaceutical Abstracts, Medline, Pascal, SciSearch, and TOXNET databases; seven major trial registries, and the abstracts of major conferences. Using predetermined criteria for inclusion, an expert review committee critically reviewed and qualitatively evaluated all identified trials for efficacy and safety results and potential limitations. Results Sixteen studies of dual therapy regimens were critiqued for the ARV-naive population. Studies of a protease inhibitor/ritonavir in combination with the integrase inhibitor raltegravir or the nucleoside reverse transcriptase inhibitor lamivudine provided the most definitive evidence supporting a role for dual therapy. In particular, lopinavir/ritonavir or darunavir/ritonavir combined with raltegravir and lopinavir/ritonavir combined with lamivudine demonstrated noninferiority to standard of care triple therapy after 48 weeks of treatment. Thirteen trials were critiqued in ARV-experienced, virologically suppressed patients. The virologic efficacy outcomes were mixed. Although overall data regarding toxicity are limited, when compared with standard triple therapy, certain dual therapy regimens may offer advantages in renal function, bone mineral density, and limb fat changes; however, some dual combinations may elevate lipid or bilirubin levels. Conclusions The potential benefits of dual therapy regimens include reduced toxicity, improved tolerability and adherence, and reduced cost. Although the data reviewed here provide valuable insights into the effectiveness and tolerability of dual therapy regimens, it remains unclear whether these potential benefits can be maintained long-term. Appropriately powered studies with longer follow-up periods are needed to more definitively assess potential toxicity reduction advantages with dual therapy.

Human Immunodeficiency Virus (HIV)-Specific Effector CD8 T Cell Activity in Patients with Primary HIV Infection

The interferon-gamma ELISPOT assay was used to assess and compare the magnitude and breadth of human immunodeficiency virus (HIV)-specific CD8 T cell responses in treatment-naive subjects during the first year of HIV primary infection and during the chronic phase of infection. Twenty-five subjects tested within a year of exposure to HIV resulting in seroconversion and 20 subjects with chronic infection were screened for HIV peptide-specific activity by stimulating peripheral blood mononuclear cells with a panel of 5-21 HLA class I-restricted HIV peptides (mean, 11.2 +/- 3.5 HIV peptides). There was a significant correlation between the magnitude and breadth of HIV-specific effector responses and time elapsed from exposure (r=0.63 for magnitude vs. time and r=0.64 for breadth vs. time; P<.02, paired t test). Maximal breadth of the HIV gene product reactivity was achieved within 2 months of exposure for Nef-specific responses and by 4 months of exposure for responses directed to Env, Gag, and reverse transcriptase.