Increased CD127+ and decreased CD57+ T cell expression levels in HIV-infected patients on NRTI-sparing regimens.

BACKGROUND: NRTIs-sparing regimens exert favourable profiles on T-cell homeostasis associated parameters. Our aim was to analyze the effect of NRTIs sparing regimen (NRTI-sparing-cART) vs NRTIs-containing regimen (NRTI-cART), on T-cell homeostasis associated parameters in naive HIV-infected patients. METHODS: Biomarkers of cell survival (CD127) and replicative senescence (CD57), were measured by multiparametric flow cytometry for T-cell phenotyping on peripheral blood mononuclear cells (PBMCs) samples just before (baseline) and after 48 weeks of undetectable viral load in patients on NRTI-sparing-cART (N = 13) and NRTI-cART (N = 14). After 48 weeks a subgroup of patients (n = 5) on NRTI-cART switched to NRTI-sparing-cART for another additional 48 weeks. In vitro assays were performed on PBMCs from HIV-uninfected healthy donors exposed or not to HIV. To analyze the independent factors associated with type of cART bivariate and stepwise multivariate analysis were performed after adjusting for basal CD4+, CD8+ and nadir CD4+ T-cell counts. RESULTS: After 48 weeks of a NRTI-sparing-cART vs NRTI-cART patients have higher effector memory (EM) CD4+ CD127+ T-cell levels, lower EM CD4+ CD57+ T-cell levels, higher CD8+ CD127+ T-cell levels, lower CD8+ CD57+ T-cell levels and higher memory CD8+ T-cell levels. This effect was confirmed in the subgroup of patients who switched to NRTI-sparing-cART. In vitro assays confirmed that the deleterious effect of a NRTIs-containing regimen was due to NRTIs. CONCLUSIONS: The implementation of NRTI-sparing regimens, with a favourable profile in CD127 and CD57 T-cell expression, could benefit cART-patients. These results could have potential implications in a decrease in the number of Non-AIDS events.

The effects of prebiotics on microbial dysbiosis, butyrate production and immunity in HIV-infected subjects.

Altered interactions between the gut mucosa and bacteria during HIV infection seem to contribute to chronic immune dysfunction. A deeper understanding of how nutritional interventions could ameliorate gut dysbiosis is needed. Forty-four subjects, including 12 HIV+ viremic untreated (VU) patients, 23 antiretroviral therapy-treated (ART+) virally suppressed patients (15 immunological responders and 8 non-responders) and 9 HIV- controls (HIV-), were blindly randomized to receive either prebiotics (scGOS/lcFOS/glutamine) or placebo (34/10) over 6 weeks in this pilot study. We assessed fecal microbiota composition using deep 16S rRNA gene sequencing and several immunological and genetic markers involved in HIV immunopathogenesis. The short dietary supplementation attenuated HIV-associated dysbiosis, which was most apparent in VU individuals but less so in ART+ subjects, whose gut microbiota was found more resilient. This compositional shift was not observed in the placebo arm. Significantly, declines in indirect markers of bacterial translocation and T-cell activation, improvement of thymic output, and changes in butyrate production were observed. Increases in the abundance of Faecalibacterium and Lachnospira strongly correlated with moderate but significant increases of butyrate production and amelioration of the inflammatory biomarkers soluble CD14 and high-sensitivity C-reactive protein, especially among VU. Hence, the bacterial butyrate synthesis pathway holds promise as a viable target for interventions.

HIV/antiretroviral therapy-related lipodystrophy syndrome (HALS) is associated with higher RBP4 and lower omentin in plasma.

Very little information is available on the involvement of newly characterized adipokines in human immunodeficiency virus (HIV)/antiretroviral therapy (ART)-associated lipodystrophy syndrome (HALS). Our aim was to determine whether apelin, apelin receptor, omentin, RBP4, vaspin and visfatin genetic variants and plasma levels are associated with HALS. We performed a cross-sectional multicentre study that involved 558 HIV type 1-infected patients treated with a stable highly active ART regimen, 240 of which had overt HALS and 318 who did not have HALS. Epidemiologic and clinical variables were determined. Polymorphisms in the apelin, omentin, RBP4, vaspin and visfatin genes were assessed by genotyping. Plasma apelin, apelin receptor, omentin, RBP4, vaspin and visfatin levels were determined by enzyme-linked immunosorbent assay in 163 patients (81 with HALS and 82 without HALS) from whom stored plasma samples were available. Student's t test, one-way ANOVA, chi-square test, Pearson and Spearman correlations and linear regression analysis were used for statistical analyses. There were no associations between the different polymorphisms assessed and the HALS phenotype. Circulating RBP4 was significantly higher (p < 0.001) and plasma omentin was significantly lower (p 0.001) in patients with HALS compared to those without HALS; differences in plasma levels of the remaining adipokines were nonsignificant between groups. Circulating RBP4 concentration was predicted independently by the presence of HALS. Apelin and apelin receptor levels were independently predicted by body mass index. Visfatin concentration was predicted independently by the presence of acquired immunodeficiency syndrome. HALS is associated with higher RBP4 and lower omentin in plasma. These two adipokines, particularly RBP4, may be a link between HIV/ART and fat redistribution syndromes.

Pre-transplant thymic function is associated with the risk of cytomegalovirus disease after solid organ transplantation.

Cytomegalovirus (CMV) disease is an important complication in solid organ transplant recipients. Thymic function in adults is associated with specific T-cell immunity. Pre-transplant thymic function was analysed in 75 solid organ transplant patients by the use of nested PCR. The primary outcome was the incidence of CMV disease 12 months after transplantation. Using multivariable logistic regression, we studied whether pre-transplant thymic function is an independent risk factor for CMV disease after transplantation. Thymic function was related to the risk of CMV disease in CMV-seropositive recipients. In these recipients, pre-transplant thymic function of <9.5 (OR 11.27, 95% CI 1.11-114.43, p 0.040) and the use of thymoglobulin (OR 8.21, 95% CI 1.09-61.84, p 0.041) were independent risk factors for CMV disease at 12 months after transplantation. Patients with pre-transplant thymic function values of <9.5 had a higher subsequent incidence of CMV disease (24%) than patients with values of ≥ 9.5 (3%) (log-rank test: 5.727; p 0.017). The positive and negative predictive values of these pre-transplant thymic function cut-offs were 0.24 (95% CI 0.10-0.45) and 0.97 (95% CI 0.82-1.00), respectively. Pre-transplant thymic function in CMV-seropositive candidates could be useful in determining the risk of post-transplant CMV disease in solid organ transplant patients, selecting a group of low-risk candidates.

Altered metabolism of gut microbiota contributes to chronic immune activation in HIV-infected individuals.

Altered interplay between gut mucosa and microbiota during treated HIV infection may possibly contribute to increased bacterial translocation and chronic immune activation, both of which are predictors of morbidity and mortality. Although a dysbiotic gut microbiota has recently been reported in HIV+ individuals, the metagenome gene pool associated with HIV infection remains unknown. The aim of this study is to characterize the functional gene content of gut microbiota in HIV+ patients and to define the metabolic pathways of this bacterial community, which is potentially associated with immune dysfunction. We determined systemic markers of innate and adaptive immunity in a cohort of HIV-infected individuals on successful antiretroviral therapy without comorbidities and in healthy non-HIV-infected subjects. Metagenome sequencing revealed an altered functional profile, with enrichment of the genes involved in various pathogenic processes, lipopolysaccharide biosynthesis, bacterial translocation, and other inflammatory pathways. In contrast, we observed depletion of genes involved in amino acid metabolism and energy processes. Bayesian networks showed significant interactions between the bacterial community, their altered metabolic pathways, and systemic markers of immune dysfunction. This study reveals altered metabolic activity of microbiota and provides novel insight into the potential host-microbiota interactions driving the sustained inflammatory state in successfully treated HIV-infected patients.

TNF-α levels in HIV-infected patients after long-term suppressive cART persist as high as in elderly, HIV-uninfected subjects.

BACKGROUND: Chronic and systemic inflammatory alterations occur in HIV-infected patients and elderly uninfected subjects and in both scenarios these alterations are associated with the development of chronic morbidities and mortality. However, whether the levels of inflammatory alterations in untreated HIV-infected patients and elderly individuals are similar is unknown. Moreover, whether long-term antiretroviral therapy normalizes inflammatory alterations compared with HIV-uninfected persons of different age is not known. METHODS: We analysed soluble inflammatory levels [high-sensitivity C-reactive protein, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, IL-8 and IL-17] in a cohort of viraemic HIV-infected patients compared with (i) age-matched, (ii) elderly and (iii) non-survivor elderly, uninfected healthy controls. We longitudinally analysed the effect of long-term 48 and 96 week suppressive combined antiretroviral therapy (cART) on the soluble inflammatory levels compared with those found in control subjects. RESULTS: Baseline IL-6 and IL-8 levels were at similar or lower concentrations in untreated patients compared with healthy elderly individuals. However, TNF-α and IFN-γ levels broadly exceeded those found in survivors and non-survivor elderly individuals. Long-term suppressive cART normalized most of the inflammatory markers, with the exception of TNF-α levels, which persisted as high as those in elderly non-survivor controls. CONCLUSIONS: Chronic inflammatory alterations associated with HIV infection are maintained at a different level from those of ageing. The persistent alteration of TNF-α levels in HIV-infected patients might cause tissue damage and have implications for developing non-AIDS-defining illnesses, even when HIV replication is long-term controlled by cART.

Specific patterns of CD4-associated immunosenescence in vertically HIV-infected subjects.

Vertical transmission of human immunodeficiency virus (HIV) represents an important world-wide health problem although the incidence in developed countries has been drastically reduced by the extensive use of highly active antiretroviral therapy. Vertically HIV-infected subjects have been exposed to the virus during the maturation of their immune systems and have suffered a persistent chronic activation throughout their lifetime; the consequences of this situation for their immune system are not fully understood. The objective of this study was to analyse immunosenescence-related parameters in different CD4 T-cell subsets. Fifty-seven vertically HIV-infected subjects and 32 age-matched healthy subjects were studied. Activation (HLA(-) DR(+) ), senescence (CD28(-) CD57(+) ) and proliferation (Ki67(+) ) were analysed on different CD4 T-cell subsets: naive (CD45RA(+) CD27(+) ), memory (CD45RO(+) CD27(+) ), effector memory (CD45RO(+) CD27(-) ) and effector memory RA (CD45RA(+) CD27(-) ). Compared with healthy subjects, vertically HIV-infected subjects showed increased naive and memory CD4 T-cell frequencies (p 0.035 and p 0.010, respectively) but similar frequencies of both effector subsets. Whereas naive CD4 T cells were not further altered, memory CD4 T cells presented increased levels of senescence and proliferation markers (p <0.001), effector memory CD4 T cells presented increased levels of activation, senescence and proliferation markers (p <0.001) and effector memory RA CD4 T cells presented increased levels of activation and senescence (p <0.001) compared with healthy subjects. Despite long periods of infection, vertically HIV-infected subjects show specific patterns of immunosenescence, revealing a preserved CD4 T-cell homeostasis for subset differentiation and distribution. Nevertheless, excepting the naive subpopulation, all subsets experienced some immunosenescence, pointing to uncertain consequences of the future aging process in these subjects.

Correlation of the virological response to short-term maraviroc monotherapy with standard and deep-sequencing-based genotypic tropism prediction methods.

Genotypic tropism testing methods are emerging as the first step before prescription of the CCR5 antagonist maraviroc (MVC) to HIV-infected patients in Europe. Studies validating genotypic tests have included other active drugs that could have potentially convoluted the effects of MVC. The maraviroc clinical test (MCT) is an in vivo drug sensitivity test based on the virological response to a short-term exposure to MVC monotherapy. Thus, our aim was to compare the results of genotypic tropism testing methods with the short-term virological response to MVC monotherapy. A virological response in the MCT was defined as a ≥ 1-log(10) decrease in HIV RNA or undetectability after 8 days of drug exposure. Seventy-three patients undergoing the MCT were included in this study. We used both standard genotypic methods (n = 73) and deep sequencing (n = 27) on MCT samples at baseline. For the standard methods, the most widely used genotypic algorithms for analyzing the V3 loop sequence, geno2pheno and PSSM, were used. For deep sequencing, the geno2pheno algorithm was used with a false-positive rate cutoff of 3.5. The discordance rates between the standard genotypic methods and the virological response were approximately 20% (including mostly patients without a virological response). Interestingly, these discordance rates were similar to that obtained from deep sequencing (18.5%). The discordance rates between the genotypic methods (tropism assays predictive of the use of the CCR5 coreceptor) and the MCT (in vivo MVC sensitivity assay) indicate that the algorithms used by genotypic methods are still not sufficiently optimized.

Hepatitis C virus replication in Caucasian HIV controllers.

Whether HIV controllers, patients who spontaneously control HIV viraemia, are able to control hepatitis C virus (HCV) infection, in terms of spontaneous clearance or lower HCV replication, is not well understood. To assess to what extent Caucasian HIV controllers are able to control HCV replication and potential associated factors, plasma HIV-1 and HCV RNA levels, anti-HCV antibodies, HCV genotype and human leucocyte antigens (HLA) typing were determined in samples from 75 HIV controllers (33 viraemic controllers, <1000 HIV-1 RNA copies/mL, and 42 elite controllers, <40 HIV-1 RNA copies/mL) and compared with 261 HIV-infected noncontrollers. We did not find differences in the HCV spontaneous clearance rates between groups. However, we interestingly found a lower HCV viral load in HIV controllers, alongside a different distribution of HCV genotypes in relation to the comparison group. In addition, HLA-B57 was associated with a lower HCV viral load in the control group and HIV controllers, and conversely, HLA-B35 with higher HCV viral load in HIV controllers. The subrepresentation of HCV genotype 1 and the overrepresentation of HLA-B57 only partly explained the lower HCV viral load found in HIV controllers. In fact, HIV controller status was independently associated with lower HCV viral load, together with HCV genotype non-1, the presence of HLA-B57 and absence of HLA-B35. Caucasian HIV controllers are able to better control HCV replication, in terms of lower HCV viral load levels. These findings support the idea that some common host mechanisms are involved in the defence against these two persistent infections.