Mireia Arnedo

The virological and immunological consequences of structured treatment interruptions in chronic HIV-1 infection

BackgroundSome individuals with chronic HIV-1 infection have discontinued their drug therapy with consequent plasma virus rebound. In a small number of patients, a delayed or absent rebound in plasma virus load has been noted after drug cessation, apparently associated with prior drug interruptions and autologous boosting of HIV-1 specific immune responses. We hypothesized that cyclic structured treatment interruptions structured treatment interruptions (STI) could augment HIV-1 specific immune responses in chronic HIV-1 infection, which might help to control HIV-1 replication off therapy. MethodsWe initiated an STI pilot study in 10 antiretroviral treatment-naive HIV-1 chronically infected subjects with baseline CD4 T-cell counts > 500 × 106 cells/l and plasma viral load > 5000 copies/ml who received highly active antiretroviral therapy (HAART) for 1 year with good response (plasma viral load < 20 copies/ml for at least 32 weeks). Three cycles of HAART interruption were performed. ResultsIn all of the patients viral load rebounded, but doubling times increased significantly between the first and third stops (P = 0.008), and by the third stop, six out of nine subjects had a virological set-point after a median 12 months off therapy that was lower than baseline before starting HAART (ranging from 0.6 log10 to 1.3 log10 lower than baseline) and in four it remained stable below 5000 copies/ml. Those subjects who controlled viral replication developed significantly stronger HIV-1 specific cellular immune responses than subjects lacking spontaneous decline (P < 0.05). During viral rebounds no genotypic or phenotypic changes conferring resistance to reverse trancriptase inhibitors or protease inhibitors was detected, but mean absolute CD4 T-cell counts declined significantly, although never below 450 × 106/l and the mean value at 12 months off therapy was significantly higher than the pre-treatment level (P = 0.004). ConclusionsOur findings suggest that STI in chronic HIV-1 infection might augment HIV-1-specific cellular immune responses associated with a spontaneous and sustained drop in plasma viral load in some subjects but at the potential cost of lower CD4 T-cell counts.

Contribution of 20 single nucleotide polymorphisms of 13 genes to dyslipidemia associated with antiretroviral therapy

Background HIV-1 infected individuals have an increased cardiovascular risk which is partially mediated by dyslipidemia. Single nucleotide polymorphisms in multiple genes involved in lipid transport and metabolism are presumed to modulate the risk of dyslipidemia in response to antiretroviral therapy. Methods The contribution to dyslipidemia of 20 selected single nucleotide polymorphisms of 13 genes reported in the literature to be associated with plasma lipid levels (ABCA1, ADRB2, APOA5, APOC3, APOE, CETP, LIPC, LIPG, LPL, MDR1, MTP, SCARB1, and TNF) was assessed by longitudinally modeling more than 4400 plasma lipid determinations in 438 antiretroviral therapy-treated participants during a median period of 4.8 years. An exploratory genetic score was tested that takes into account the cumulative contribution of multiple gene variants to plasma lipids. Results Variants of ABCA1, APOA5, APOC3, APOE, and CETP contributed to plasma triglyceride levels, particularly in the setting of ritonavir-containing antiretroviral therapy. Variants of APOA5 and CETP contributed to high-density lipoprotein-cholesterol levels. Variants of CETP and LIPG contributed to non-high-density lipoprotein-cholesterol levels, a finding not reported previously. Sustained hypertriglyceridemia and low high-density lipoprotein-cholesterol during the study period was significantly associated with the genetic score. Conclusions Single nucleotide polymorphisms of ABCA1, APOA5, APOC3, APOE, and CETP contribute to plasma triglyceride and high-density lipoprotein-cholesterol levels during antiretroviral therapy exposure. Genetic profiling may contribute to the identification of patients at risk for antiretroviral therapy-related dyslipidemia.

Effect of mycophenolate mofetil on immune response and plasma and lymphatic tissue viral load during and after interruption of highly active antiretroviral therapy for patients with chronic HIV infection a randomized pilot study

Summary: The main goal of this study was to assess the role of mycophenolate mofetil (MMF) during interruption of highly active antiretroviral therapy (HAART). Seventeen patients with early-stage chronic HIV type 1 infection were treated with HAART for 12 months. They were then randomized (day 0) to receive MMF (HAART–MMF group, n = 9) or to continue the regimen (HAART group, n = 6) for 120 additional days. At day 120 in the HAART–MMF group, HAART was discontinued, and MMF administration was continued. The primary end point of the study was the number of individuals maintaining a plasma viral load (VL) set point of <200 copies/mL after at least 6 months off HAART. At day 120, all patients in both groups had undetectable plasma VLs. After 6 months off HAART, 5 of 9 patients in the HAART–MMF group versus 1 of 6 patients in the HAART group maintained a plasma VL of <200 copies/mL (P = 0.28). According to the ability of their plasma to inhibit cellular proliferation, patients were reclassified and divided into an inhibition group (n = 6) and a no inhibition group (n = 9). The doubling time of VL rebound was significantly higher in the inhibition group (mean ± SE, 10.22 ± 1.3) than in the no inhibition group (mean ± SE, 4.6 ± 1.6; P = 0.03). Moreover, 5 of 6 patients in the inhibition group maintained a plasma VL of <200 copies/mL versus 1 of 9 patients in the no inhibition group (P = 0.005) after 6 months off HAART. We found that combining MMF and HAART delayed VL rebound and improved control of viral replication without HAART but only when inhibition of lymphocyte proliferation was achieved.

Contribution of Genetic Background, Traditional Risk Factors, and HIV-Related Factors to Coronary Artery Disease Events in HIV-Positive Persons

BACKGROUND Persons infected with human immunodeficiency virus (HIV) have increased rates of coronary artery disease (CAD). The relative contribution of genetic background, HIV-related factors, antiretroviral medications, and traditional risk factors to CAD has not been fully evaluated in the setting of HIV infection. METHODS In the general population, 23 common single-nucleotide polymorphisms (SNPs) were shown to be associated with CAD through genome-wide association analysis. Using the Metabochip, we genotyped 1875 HIV-positive, white individuals enrolled in 24 HIV observational studies, including 571 participants with a first CAD event during the 9-year study period and 1304 controls matched on sex and cohort. RESULTS A genetic risk score built from 23 CAD-associated SNPs contributed significantly to CAD (P = 2.9 × 10(-4)). In the final multivariable model, participants with an unfavorable genetic background (top genetic score quartile) had a CAD odds ratio (OR) of 1.47 (95% confidence interval [CI], 1.05-2.04). This effect was similar to hypertension (OR = 1.36; 95% CI, 1.06-1.73), hypercholesterolemia (OR = 1.51; 95% CI, 1.16-1.96), diabetes (OR = 1.66; 95% CI, 1.10-2.49), ≥ 1 year lopinavir exposure (OR = 1.36; 95% CI, 1.06-1.73), and current abacavir treatment (OR = 1.56; 95% CI, 1.17-2.07). The effect of the genetic risk score was additive to the effect of nongenetic CAD risk factors, and did not change after adjustment for family history of CAD. CONCLUSIONS In the setting of HIV infection, the effect of an unfavorable genetic background was similar to traditional CAD risk factors and certain adverse antiretroviral exposures. Genetic testing may provide prognostic information complementary to family history of CAD.

Relevance of HIV-1-specific CD4+ helper T-cell responses during structured treatment interruptions in patients with CD4+ T-cell nadir above 400/mm3

Objectives: To analyze the dynamics of both HIV-1-specific CD4+ and CD8+ T-cell responses during structured treatment interruptions (STIs) in chronically HIV-1-infected (CHI) patients and to correlate them with the viral set point achieved. Methods: Forty-five early-stage CHI patients who were on highly active antiretroviral therapy (HAART) for at least 1 year and underwent STI were included. Plasma viral load (VL), peripheral blood mononuclear cell (PBMC) lymphoproliferative (LPR) response to HIV p24 protein, and HIV-1 epitope-specific interferon-γrelease from CD8+ T cells were measured over a minimum study period of 2 years. Results: VL set point during final STI was both significantly lower than, and positively correlated to, baseline VL (P < 0.0001: mean VL reduction 0.77 log10, and r = 0.42, P = 0.004, respectively). CD4+ LPRs to p24 increased significantly (P = 0.001) between day 0 of the first STI cycle and 4th STI but decreased thereafter. VL set point during final STI was significantly and negatively correlated with LPRs to p24 at both 2nd STI and 4th STI. Nevertheless, at week 52, 12 weeks after the end of the last STI, LPRs were weak and transient in all patients and were not correlated with VL set point. Moreover, the magnitude and breadth of HIV-1-specific CD8+ T-cell responses increased significantly (P < 0.0001) between day 0 and week 52. The largest increases occurred during the final STI. Even though VL reached set point by week 12 of the final STI, HIV-1-specific CD8+ T-cell responses did not stabilize but rather increased until the end of the follow-up and did not correlate with plasma VL (r = 0.01, P = 0.88). Conclusions: STIs do not lead to control of viral replication in CHI patients, probably due to the fact that boosted CTL responses lack strong and durable helper T-cell responses. To reset the VL set point, new approaches that effectively augment and preserve helper T-cell responses should be investigated.

Impact of genetic factors on dyslipidemia in HIV-infected patients starting antiretroviral therapy.

Objective:The impact of host genetic factors on the incidence of dyslipidemia in antiretroviral-naive HIV patients starting antiretroviral therapy (ART) is not clear. We assessed the role of single nucleotide polymorphisms (SNPs) identified from previous genome-wide association studies adjusting for the contribution of nongenetic factors. Methods:We assessed 192 SNPs in an HIV cohort who started ART (1997–2008) including a protease inhibitor or a nonnucleoside reverse transcriptase inhibitor (NNRTI). Patients had fasting plasma lipids, total cholesterol (T-Chol), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides measured prior to their ART initiation and after 1 year. A logistic regression model was constructed and multiple test was corrected using 10% false discovery rate (FDR). Haplotypes and gene interactions were analysed. Results:A total of 727 individuals were successfully genotyped (n = 381_PI-group; n = 346_NNRTI-group). Age and hepatitis C virus (HCV) coinfection were associated with increases and decreases in T-Chol and LDL-C (P < 0.01), respectively. Protease inhibitor containing ART showed an unfavourable association with T-Chol (P < 0.01) and triglycerides (P = 7.4E−4) and NNRTI-containing ART was favourably associated with HDL-C (P < 0.01). Moreover, SNPs in apolipoprotein B (APOB) were associated with an increase of LDL-C [rs10495712 (P = 3.18E-4); rs754524 (P = 1.26E−3)]. Six SNPs in three genes showed an association with a favourable effect on HDL-C levels when ART included NNRTI: ABCA1 (rs4149313, P = 2.97E-4), LIPC (rs1800588, P = 2.13E-3; rs473224, P = 3.06E-4; rs261336, P = 2.23E−3) and CETP (rs173539, P = 2.96E−3; rs3764261, P = 1.52E-3). After 10% FDR correction for multiple testing, one and six SNPs displayed significant associations with LDL-C and HDL-C, respectively. Conclusion:In HIV-infected patients staring ART, one SNP in APOB was associated with an increase of LDL-C. SNPs in ABCA1/LIPC/CETP were favourably associated with HDL-C when ART included NNRTI. However, an unfavourable effect on T-Chol and triglyceride levels was observed when ART included protease inhibitor. The risk of hypercholesterolaemia increased with age and decreased with HCV coinfection. These findings might help to individualize the selection of ART.

Primary human immunodeficiency virus type 1 infection: clinical, virological and immunological characteristics of 75 patients (1997-2003)

OBJECTIVES To describe the epidemiological and clinical characteristics and the evolution of a cohort of patients with primary HIV-1 infection from the Barcelona area. METHODS Prospective cohort study of HIV-infected patients diagnosed with primary HIV infection in a tertiary hospital in Barcelona (Spain) from 1997 through 2003. Descriptive analysis of epidemiological and clinical characteristics and effect of highly active antiretroviral treatment (HAART) on outcome. RESULTS A total of 75 patients were diagnosed, accounting for 2.9% of the total of newly diagnosed HIV patients during the same time period. Eighty-one percent of the patients were males and the median age was 30 years (IQR 26-38). The most frequent transmission route was homosexual (72%), followed by heterosexual (17%) and intravenous drug abuse (11%). Seventy-seven percent of patients presented symptoms, the most frequent being fever (98%), asthenia (86%), arthralgia-myalgia (65%), lymphadenopathy (55%), night sweats (48%) and rash. Sixty-five percent started HAART, although the proportion of patients that received HAART decreased from 79% during the period 1997-2000 to 49% during the period 2001-2003 (p < 0.01). After a median follow-up of 37 months (IQR 26-66), one patient died and eight cases were lost to follow-up. The patients who did not receive HAART had a higher probability of immunological or clinical deterioration during the follow-up when compared to the group that received HAART (42.3% versus 12.3%; p < 0.001). In treated patients, dyslipidemia and lipodystrophy were diagnosed in 58% and 37% of cases, respectively. CONCLUSIONS Primary HIV-1 infection was diagnosed more frequently in homosexual males, and its clinical characteristics were similar to those observed in previous studies. HAART given during primary HIV infection was effective, but was associated with a high percentage of adverse effects.

Lymphoid tissue viral burden and duration of viral suppression in plasma

Objectives To assess virological response in lymphoid tissue and its impact on the durability of response in plasma in HIV-1-infected persons who achieved sustained suppression of plasma viraemia with different antiretroviral regimens. Methods Consecutive patients on first-line antiretroviral therapy were included if they had a plasma HIV-1 RNA viraemia < 20 copies/ml within the last 6 months and tonsillar tissue accesible for biopsy. First-line therapy contained two nucleoside analogues: alone (2NRTI group, n = 3); plus a HIV-1 protease inhibitor (PI group, n = 11) or plus nevirapine (NVP group; n = 16). Patients were followed until virus was detectable in plasma, they changed therapy or were lost to follow-up. Results Tonsillar HIV-1 RNA could be detected (> 100 copies/mg) in 10 patients: one in the PI group (9%), six (38%) in the NVP group and in all three patients in the 2NRTI group. Primary resistance mutations could be detected in only 2 of these 10 patients. After a median of 9 months after the biopsies, viral suppression in plasma had failed in 6 of these 10 patients whereas failure had only occurred in 1 out of 20 with initially undetectable viral load in lymphoid tissue (P = 0.01; log rank test). Conclusions In patients with sustained viral suppression in plasma, triple therapy including a HIV-1 protease inhibitor was more potent than triple therapy containing nevirapine or dual therapy with nucleoside analogues to reduce viral burden in lymphoid tissue. A worse response in lymphoid tissue could not be explained by local selection of resistance and was associated with a less durable virological response in plasma.

Immunological and virological factors at baseline may predict response to structured therapy interruption in early stage chronic HIV-1 infection

BackgroundThe objective was to analyse which baseline factors could predict a favourable outcome after structured therapy interruption (STI). MethodsData of three Spanish pilot studies of STI in early stage chronic HIV-1-infected patients were analysed. A set of 37 variables at baseline was used. Plasma and tonsillar tissue viral load (VL), lymphocyte immunophenotyping and proliferative responses (LPR) to mitogens and specific antigens, and HIV-1 specific cytotoxic T lymphocyte responses were assessed at baseline. Response was defined as a VL set-point after 6 months off antiretroviral therapy after the last interruption of < 5000 copies/ml and 0.5 log10 below baseline PVL before any antiretroviral therapy. ResultsAfter STI, the 44 patients were classified as follows: 18 (41%) as responders, 26 (59%) as non-responders. In the univariate analysis patients who responded had a significantly lower baseline level of CD4CD38 (P = 0.0068) and naive CD4 T cells (P = 0.03), and a higher level of memory CD4 T cells (P = 0.03) and proliferative response to tetanus toxoid (TT) (P = 0.01) and HIV-1 p24 (P = 0.03) than non-responders. A model incorporating five qualitative variables transformed according to the median value (CD4CD38, CD4 naive and memory T cells and stimulation index to TT and HIV-1 p24) at baseline could classify 97% of patients correctly (P = 0.0001). ConclusionsA level of memory CD4 T cells and proliferative response to recall antigens above the median may predict a good response to STI, suggesting that preserved memory response in CD4 T cells is important factor.

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/&mgr;l (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/&mgr;l 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.