Adherence to a Supplemented Mediterranean Diet Drives Changes in the Gut Microbiota of HIV-1-Infected Individuals.

OBJECTIVE: The health effects of a supplemented Mediterranean diet (SMD) with extra-virgin olive oil (EVOO) and nuts are well documented in non-HIV-infected individuals. We hypothesised that the benefits of an SMD could be mediated by changes in the gut microbiota, even in those with an altered intestinal microbiota such as people living with HIV. DESIGN: Individuals living with HIV (n = 102) were randomised to receive an SMD with 50 g/day of EVOO and 30 g/day of walnuts (SMD group) or continue with their regular diet (control group) for 12 weeks. METHODS: Adherence to the Mediterranean diet was assessed using the validated 14-item MD-Adherence-Screener (MEDAS) from the PREDIMED study. A sub-study classifying the participants according to their MEDAS scores was performed. RESULTS: The lipid profile was improved in the SMD group vs. that in the control group (delta-total cholesterol and delta-B-lipoprotein). The immune activation (CD4+HLADR+CD38+ and CD8+HLADR+CD38+ cells) and IFN-γ-producing T-cells significantly decreased at week 12 compared to the baseline in the SMD group but not in the control group. The gut microbiota in those from the high-adherence group presented significantly high diversity and richness at the end of the intervention. Succinivibrio and Bifidobacterium abundances were influenced by the adherence to the MD and significantly correlated with Treg cells. CONCLUSION: The Mediterranean diet improved metabolic parameters, immune activation, Treg function, and the gut microbiota composition in HIV-1-infected individuals. Further, Mediterranean diet increased the Bifidobacterium abundances after the intervention, and it was associated to a beneficial profile.

New challenges in therapeutic vaccines against HIV infection.

INTRODUCTION: There is a growing interest in developing curative strategies for HIV infection. Therapeutic vaccines are one of the most promising approaches. We will review the current knowledge and the new challenges in this research field. Areas covered: PubMed and ClinicalTrial.gov databases were searched to review the progress and prospects for clinical development of immunotherapies aimed to cure HIV infection. Dendritic cells (DC)-based vaccines have yielded the best results in the field. However, major immune-virologic barriers may hamper current vaccine strategies. We will focus on some new challenges as the antigen presentation by DCs, CTL escape mutations, B cell follicle sanctuary, host immune environment (inflammation, immune activation, tolerance), latent reservoir and the lack of surrogate markers of response. Finally, we will review the rationale for designing new therapeutic vaccine candidates to be used alone or in combination with other strategies to improve their effectiveness. Expert commentary: In the next future, the combination of DCs targeting candidates, inserts to redirect responses to unmutated parts of the virus, adjuvants to redirect responses to sanctuaries or improve the balance between activation/tolerance (IL-15, anti-PD1 antibodies) and latency reversing agents could be necessary to finally achieve the remission of HIV-1 infection.

Predictive Factors for HIV Seroconversion Among Individuals Attending a Specialized Center After an HIV Risk Exposure: A Case-Control Study.

OBJECTIVE: To better target our current prevention strategies, we assessed factors associated with HIV seroconversion in individuals attending a specialized center after a risk exposure. MATERIALS AND METHODS: We studied individuals from an HIV Unit's contact risk cohort at a tertiary care hospital in Barcelona, Spain, between 2003 and 2013 and performed a retrospective matched case-control study. Cases were individuals who seroconverted to HIV after at least 3 months since first follow-up visit for a contracting risk. Controls were HIV-negative individuals from the same cohort. Demographics and behavior variables were studied and compared using a McNemar test assessing factors associated with seroconversion. Univariate analysis and binary logistic regression were performed to develop a model for predicting probability of HIV seroconversion. We also evaluated sensitivity and specificity of our model and an area under Receiver Operating Characteristic (ROC) curve was estimated. RESULTS: Sixty-nine (2.2%) individuals seroconverted after a median (interquartile range) of 24 (9-34) months since last follow-up. Seroconverters were predominantly male (96%) and men who have sex with men (MSM) (94%). No differences were observed regarding risk of exposure. Being MSM [odds ratio (OR) 5.2 (1.4-20.2), p = .01], having a known HIV-positive partner [OR 2.7 (1.2-6.2), p = .02], previous postexposure prophylaxis (PEP) [OR 3.9 (1.0-15.6), p = .05], and having previous sexually transmitted infections (STIs) [OR 4.6 (1.9-10.9), p = .001] were the factors independently associated with HIV seroconversion. The sensitivity and specificity of our model were 64.06% and 73.53%, respectively, and the area under ROC curve was 0.777. DISCUSSION: HIV seroconversions were observed frequently between individuals attending a specialized center because of a risk exposure. Being MSM, having had previous PEP, an HIV-positive sexual partner, and previous STI were predictive factors for HIV seroconversion. Closer and longer follow-up and/or pre-exposure prophylaxis should be considered to prevent HIV infections in this high-risk population.

A randomized clinical trial comparing ritonavir-boosted lopinavir versus raltegravir each with tenofovir plus emtricitabine for post-exposure prophylaxis for HIV infection.

OBJECTIVES: The objective of this study was to assess post-exposure prophylaxis (PEP) non-completion at day 28, comparing two regimens. METHODS: A prospective, open, randomized clinical trial was conducted at a tertiary hospital in Barcelona, Spain. Individuals attending the emergency room because of potential sexual exposure to HIV were randomized to tenofovir disoproxil/emtricitabine (245/200 mg) plus either ritonavir-boosted lopinavir (400/100 mg) or raltegravir (400 mg). The primary endpoint was PEP non-completion at day 28. Secondary endpoints were adherence, adverse events and rate of seroconversions. This study was registered in ClinicalTrials.gov: NCT01576731. RESULTS: One-hundred-and-twenty-one individuals were randomized to receive ritonavir-boosted lopinavir and 122 to raltegravir (n = 243). PEP non-completion at day 28 was 43% with no significant difference between arms. We performed a modified ITT analysis including only those patients who attended on day 1 (n = 191). PEP non-completion in this subgroup was higher in the ritonavir-boosted lopinavir arm than in the raltegravir arm (34.6% versus 20.4%, P = 0.04), as was the number of patients lost to follow-up at day 28 (32.6% versus 21.6%, P = 0.08) and the proportion of patients with low adherence (49.2% versus 30.8%, P = 0.03). Adverse events were significantly more common in the ritonavir-boosted lopinavir arm (73.4% versus 60.2%, P = 0.007). There was an HIV seroconversion at day 90 in the raltegravir arm in a patient who had multiple potential sexual risk exposures before and after receiving PEP. CONCLUSIONS: Although we found no differences between arms regarding PEP non-completion, poor adherence and adverse events were significantly higher in patients allocated to tenofovir disoproxil/emtricitabine plus ritonavir-boosted lopinavir. These data support the use of raltegravir as the preferred third drug in current PEP recommendations.

A randomized clinical trial comparing ritonavir-boosted lopinavir versus maraviroc each with tenofovir plus emtricitabine for post-exposure prophylaxis for HIV infection.

OBJECTIVES: The objective of this study was to assess post-exposure prophylaxis (PEP) non-completion at day 28, comparing ritonavir-boosted lopinavir versus maraviroc, both with tenofovir disoproxil/emtricitabine as the backbone. METHODS: We conducted a prospective, open, randomized clinical trial. Individuals attending the emergency room because of potential sexual exposure to HIV and who met criteria for receiving PEP were randomized to one of two groups: tenofovir disoproxil/emtricitabine (245/200 mg) once daily plus either ritonavir-boosted lopinavir (400/100 mg) or maraviroc (300 mg) twice daily. Five follow-up visits were scheduled for days 1, 10, 28, 90 and 180. The primary endpoint was PEP non-completion at day 28. Secondary endpoints were adherence, adverse events and rate of seroconversions. This study was registered in ClinicalTrials.gov: NCT01533272. RESULTS: One-hundred-and-seventeen individuals were randomized to receive ritonavir-boosted lopinavir and 120 to maraviroc (n = 237). PEP non-completion at day 28 was 38% (n = 89), with significant differences between arms [ritonavir-boosted lopinavir 44% (n = 51) versus maraviroc 32% (n = 38), P = 0.05]. We performed a modified ITT analysis including only those patients who attended on day 1 (n = 182). PEP non-completion in this subgroup was also significantly higher in the ritonavir-boosted lopinavir arm (27% versus 13%, P = 0.004). The proportion of patients with low adherence was similar between arms (52% versus 47%, P = 0.56). Adverse events were reported by 111 patients and were significantly more common in the ritonavir-boosted lopinavir arm (72% versus 51%, P = 0.003). No seroconversions were observed during the study. CONCLUSIONS: PEP non-completion and adverse events were both significantly higher in patients allocated to ritonavir-boosted lopinavir. These data suggest that maraviroc is a well-tolerated antiretroviral that can be used in this setting.

Association of microbial translocation biomarkers with clinical outcome in controllers HIV-infected patients.

BACKGROUND: A proportion of patients who spontaneously control viral load (controllers) experienced clinical progression. We hypothesized that microbial translocation would independently determine the rate of disease progression in controllers. METHODS: sCD14, lipopolysaccharide-binding protein (LBP) and EndoCab levels were assessed in 114 antiretroviral-naive patients with CD4(+) T cells above 500 cells/µl (including 63 controllers and 51 noncontrollers). The independent predictive value of these markers on time to progression to the combined endpoint of AIDS, non-AIDS event, initiation of combination antiretroviral therapy (cART) or CD4(+) cell count less than 500 cells/µl was assessed using a Cox regression model. RESULTS: Most of the patients progressed to a combined endpoint (60%). Clinical progression in controllers was significantly lower than in noncontrollers (P = 0.02). Controllers with lower than the median baseline CD4(+) T-cell count and higher than the median baseline viral load, sCD14 and EndoCab levels had a worse prognosis (P < 0.0001, P = 0.007, P = 0.05 and P = 0.012), while noncontrollers with higher than the median baseline LBP level also had a worse prognosis (P = 0.019). sCD14 and LBP increased and EndoCab decreased over time [from baseline (median values: 1486, 17604 ng/ml and 68 MMU/ml, respectively, to the date of event or the last determination (median values: 1663, 20230 ng/ml and 49 MMU/ml), respectively] in controllers (P = 0.04, 0.08 and 0.0006, respectively). CONCLUSION: Microbial translocation seems to be an important determinant of clinical progression in HIV-infected controllers independently of viremia. Measures to improve the intestinal mucosa damage or decrease translocation could influence the outcome in these patients.

Protease inhibitor monotherapy is associated with a higher level of monocyte activation, bacterial translocation and inflammation.

INTRODUCTION: Monotherapy with protease-inhibitors (MPI) may be an alternative to cART for HIV treatment. We assessed the impact of this strategy on immune activation, bacterial translocation and inflammation. METHODS: We performed a cross-sectional study comparing patients on successful MPI (n=40) with patients on cART (n=20). Activation, senescence, exhaustion and differentiation stage in CD4+ and CD8+ T lymphocyte subsets, markers of monocyte activation, microbial translocation, inflammation, coagulation and low-level viremia were assessed. RESULTS: CD4+ or CD8+ T lymphocyte subset parameters were not significantly different between both groups. Conversely, as compared with triple cART, MPI patients showed a higher proportion of activated monocytes (CD14+ CD16-CD163+ cells, p=0.031), soluble markers of monocyte activation (sCD14 p=0.004, sCD163 p=0.002), microbial translocation (lipopolysaccharide (LPS)-binding protein; LBP p=0.07), inflammation (IL-6 p=0.04) and low-level viremia (p=0.035). In a multivariate model, a higher level of CD14+ CD16-CD163+ cells and sCD14, and presence of very low-level viremia were independently associated with MPI. Monocyte activation was independently associated with markers of inflammation (IL-6, p=0.006), microbial translocation (LBP, p=0.01) and low-level viremia (p=0.01). CONCLUSIONS: Patients on MPI showed a higher level of monocyte activation than patients on standard therapy. Microbial translocation and low-level viremia were associated with the high level of monocyte activation observed in patients on MPI. The long-term clinical consequences of these findings should be assessed.

Immunological function restoration with lopinavir/ritonavir versus efavirenz containing regimens in HIV-infected patients: a randomized clinical trial.

CD4(+) count increase has been reported to be different with lopinavir/r (LPV/r) and efavirenz (EFV)-containing regimens. The different effect of these two regimens on other immune function parameters and the relationship with the gain of CD4(+) count have not been assessed in a randomized clinical trial. Fifty antiretroviral treatment (cART) naïve HIV-infected individuals were randomized to receive LPV/r or EFV both with tenofovir/emtricitabine for 48 weeks. A substudy of immunological function restoration was performed in 22 patients (LPV/r n=10 and EFV n=12). Activation, thymic function, apoptosis, senescence, exhaustion, Treg cells, interleukin (IL)-7-receptor/IL-7 system, thymic volume, and lymphoid tissue fibrosis were evaluated at baseline and at week 48. Both groups experienced a CD4(+) count increase that was higher in the EFV group (ΔCD4(+) 88 vs. 315 cells/µl LPV/r vs. EFV, respectively, p<0.001). Despite this difference in CD4(+) gain, the change in other immune function parameters was similar in both treatment groups. Most of parameters evaluated tended to normalize after 48 weeks of cART. A significant decrease in levels of activation, senescence, exhaustion, and apoptosis on CD4(+) and CD8(+) T cells (p<0.001 for all) and a significant increase in markers of thymic function, IL-7 receptor, and in the levels of central memory CD4(+) T cells and naive subsets of CD8(+) T cells (p<0.001 for all) with respect to baseline values were observed without any difference between groups. These data indicate that the differences in CD4(+) gain with different cART regimens are not immunologically meaningful and might explain the similar clinical efficacy of these regimens.

Rate and predictors of non-AIDS events in a cohort of HIV-infected patients with a CD4 T cell count above 500 cells/mm³.

The reduction of risk of non-AIDS events after combined antiretroviral therapy (cART) initiation and the crude incidence rate (CIR) of these events in patients who control the viral load without cART (controllers) in a cohort of 574 antiretroviral-naive patients with a baseline CD4 T cell count above 500 cells/mm³ were assessed. Non-AIDS severe events were defined as a first admission to the hospital due to non-AIDS-defining malignancies, cardiovascular, neuropsychiatric, liver-related, or end-stage renal disease events. Potential determinants of non-AIDS/death events were studied using Cox regression models. Eighty-five non-AIDS/death events occurred during 6,062 persons-years of follow-up (PYFU) with a CIR of 1.4 per 100 PYFU. Factors associated with non-AIDS/death event were age (HR 3.4; 95% CI: 1.6-6.9), nadir CD4 below 350 cells/mm³ (HR 2.5; 95% CI: 1.4-4.6), and a last determination of viral load above the median (HR 1.9; 95% CI: 1.0-3.3). The CIR of non-AIDS/death events was 2.1 and 1.8 per 100 PYFU before and after cART in patients who started cART (n=446). A reduction of CIR of non-AIDS events after cART initiation was observed only in patients with a nadir of CD4 above 350 cells/mm³ (2.5 vs. 0.6 per 100 PYFU, p=0.004, and remained stable after cART in patients with a median nadir of CD4 below 350 cells/mm³. CIR was similar in elite, viremic, and noncontrollers (1.1, 1.0, and 1.5 per 100 PYFU, respectively, p=0.25). Reduction of CIR of non-AIDS events after cART initiation depends on nadir CD4 T cell count. Most of the controllers patients had a CIR similar to noncontrollers. These data support the early initiation of cART in HIV-infected patients.