Serum Trimethylamine-N-oxide Concentrations in People Living with HIV and the Effect of Probiotic Supplementation.

BACKGROUND: The incidence of cardiovascular disorders in people living with HIV (PLWH) is higher than that in non-infected individuals. Traditional and specific risk factors have been described but the role of the gut microbiota-dependent choline metabolite, trimethylamine-N-oxide (TMAO) is still unclear. METHODS: A cross-sectional analysis and a longitudinal analysis (with high-dose probiotic supplementation) were performed to measure serum TMAO concentrations through UHPLC-MS/MS. Stable outpatients living with HIV on highly active antiretroviral treatment with no major cardiovascular disease were enrolled. Non-parametric tests (bivariate and paired tests) and a multivariate linear regression analysis were used. RESULTS: A total of 175 participants were enrolled in the study. Median serum TMAO concentrations were 165 (103-273) ng/mL. An association with age, serum creatinine, number of antiretrovirals, multimorbidity and polypharmacy was observed; at linear logistic regression analysis, multimorbidity was the only independent predictor of TMAO concentrations. Carotid intima media thickness (IMT) was 0.85 (0.71-1.21) mm, with a trend towards higher TMAO concentrations observed in patients with IMT >0.9 mm (P=0.087). In the 25 participants who received probiotic supplementation, TMAO levels did not significantly change after 24 weeks (Wilcoxon paired P=0.220). CONCLUSION: Serum TMAO levels in PLWH were associated with multimorbidity, higher cardiovascular risk and subclinical atherosclerosis and were not affected by 6 months of high-dose probiotic supplementation.

Diagnostic accuracy of new and old cognitive screening tools for HIV-associated neurocognitive disorders.

OBJECTIVES: Considering the similarities between HIV-associated neurocognitive disorders (HAND) and neurodegenerative dementias and the frequency of executive dysfunctions among HIV-positive patients, we evaluated the accuracy of the Frontal Assessment Battery and Clock-Drawing Test together with the Three Questions Test and International HIV Dementia Scale to screen for HAND. METHODS: A cross-sectional monocentric study was conducted from 2010 to 2017. The index tests were represented by the four screening tools; the reference standard was represented by a comprehensive neurocognitive battery used to investigate 10 cognitive domains. Patients were screened by a trained infectious diseases physician and those showing International HIV Dementia Scale scores ≤ 10 and/or complaining of neurocognitive symptoms were then evaluated by a trained neuropsychologist. RESULTS: A total of 650 patients were screened and 281 received the full neurocognitive evaluation. HAND was diagnosed in 140 individuals. The sensitivity, specificity, correct classification rate and area under the receiver operating characteristic curve (AUROC) were, respectively, as follows: Frontal Assessment Battery, 40.7%, 95.1%, 68.3% and 0.81; International HIV Dementia Scale, 74.4%, 56.8%, 65.4% and 0.73; Clock-Drawing Test, 30.9%, 73.4%, 53.8% and 0.56; and Three Questions Test, 37.3%, 54.1% and 45.7%. Raising the Frontal Assessment Battery's cut-off to ≤ 16 improved its sensitivity, specificity and correct classification rate to 78.0%, 63.9% and 70.8%, respectively. CONCLUSIONS: We observed poor screening performances of the Three Questions and Clock-Drawing Tests. While the International HIV Dementia Scale showed a poor specificity, the Frontal Assessment Battery showed the highest correct classification rate and a promising performance at different exploratory cut-offs.

Therapeutic drug monitoring of boosted PIs in HIV-positive patients: undetectable plasma concentrations and risk of virological failure.

Background: Therapeutic drug monitoring (TDM) of antiretroviral drugs is performed in selected HIV-positive patients. The aim of this study was to estimate the prevalence of undetectable plasma concentrations of ritonavir and boosted PIs and to evaluate the association between those and the 48 week risk of virological failure. Methods: A TDM registry study and a retrospective follow-up study were conducted. Plasma concentrations were measured through validated methods. According to PI and ritonavir concentrations, patients were stratified as adherent, partially non-adherent or non-adherent. Virological outcome was evaluated 48 weeks afterwards. Results: The TDM registry study included 2468 samples collected from 723 patients (68.1% male, median age 43.5 years). Eighty-seven samples (3.5%, 74 patients) and 68 samples (2.8%, 52 patients) were in the partially non-adherent and non-adherent groups, respectively; more patients on atazanavir/ritonavir (7.9%) versus darunavir/ritonavir (2% twice daily and 1.9% once daily) and lopinavir/ritonavir (1.5%; P < 0.001) were observed in the partially non-adherent group. Two hundred and ninety patients were included in the follow-up study (64.1% male, median age 40 years). Patients in the adherent group had a higher chance of viral control [81.9% (167/204)] versus the partially non-adherent group and the non-adherent group [71.7% (33/46) and 53.1% (17/32), respectively; P  =   0.001]. Based on multivariate analysis, baseline HIV RNA >50 copies/mL ( P < 0.001), genotypic susceptibility score ≤2 ( P = 0.001), lower nadir CD4 cell count ( P = 0.003) and not being in the adherent group ( P = 0.029) were independent predictors of HIV RNA >50 copies/mL at 48 weeks. Conclusions: The measurement of PI and ritonavir plasma levels can uncover incomplete compliance with treatment; TDM may represent a useful tool for identifying patients in need of adherence-promoting interventions.

Raltegravir Plus Nevirapine as Maintenance Antiretroviral Therapy in HIV-Positive Patients: Safety, Efficacy and Pharmacokinetics.

BACKGROUND: Tolerability, long-term toxicities and selection of resistant variants limit the use and efficacy of antiretroviral drugs in HIV-positive patients. Novel combinations are needed for mantaining long-term control of HIV replication; nevertheless scarse data are available on protease inhibitor-free dual antiretroviral therapies. METHODS: A multi-centric retrospective study was conducted including HIV-1-positive patients on raltegravir/nevirapine dual regimens. Plasma concentrations were measured as therapeutic drug monitoring while a subset of patients underwent intensive 12-hour pharmacokinetic evaluation. RESULTS: A total of 77 patients switching from successful regimens (76.6% male, median age 52 years) was included; 10 patients on raltegravir plus nevirapine once-daily while 67 subjects on twice-daily schedule. After a median follow-up of 32 months 69 patients (89.6%) were still successfully on treatment. Three patients discontinued for side effects (skin rash or hepatoxicity). Virological failure was observed in five patients (6.5%, 3 on once-daily schedule): in 4 patients (80%) resistance-associated mutations were observed (4 reverse transcriptase, 2 integrase). Triglycerides decreased in patients switching with lipid abnormalities (n=52) and estimated creatinine clearance increased in those with less than 60 ml/min (n=13). Median trough raltegravir and nevirapine concentrations were 83 ng/ml (32-227) and 5460 ng/ml (4037-7221); intensive 12-hours pharmacokinetic parameters (n=7) were similar to published data. CONCLUSION: Dual therapy with raltegravir/nevirapine in selected patients was highly effective over a 32-month follow up: virological failure was infrequent (6.5%), most common with once-daily schedule (60%) and often associated with the selection of resistance-associated mutations (80%). Twice-daily raltegravir plus nevirapine deserves further clinical evaluation as an NRTI- and PI-sparing strategy in selected patients.

Efficacy, tolerability and virological consequences of long-term use of unboosted atazanavir plus 2 NRTIs in HIV-infected patients.

PURPOSE: Switch to unboosted atazanavir (ATV) is an attractive option due to convenience and tolerability in HIV-positive patients. With limited available data we investigated the determinants of long-term efficacy and the consequences of virological failure of unboosted atazanavir-based regimens. METHODS: Retrospective analysis in two Italian large outpatient clinics including demographic, immunovirological, resistance and pharmacokinetic data. RESULTS: 249 patients receiving atazanavir (400 mg once-daily) plus 2 NRTIs were included; 163 were males (65.5%) and median age was 47 years (42-51.5). Median CD4+ T-cell count was 396/uL (261-583); 146 (58.6%) presented a viral load < 50 copies/mL. Over a median follow up of 157 weeks (106-203) 193 patients (77.5%) were still on treatment with 10 (4%) and 2 (0.8%) stopping for virological failure or toxicity, respectively. Ten patients with virological failure presented newly selected resistance associated mutations (RAMs) for NRTIs (2/10) or ATV (4/10, one I50L). Total cholesterol and triglycerides showed significant decreases at 48 [-4 mg/dL and -41 mg/dL] and 96 weeks [-14 mg/dL and -54 mg/dL] as compared to baseline. At multivariate analysis a genotypic sensitivity score ≤ 1, atazanavir RAMs > 1 and suboptimal adherence were independently associated with virological failure; in lamivudine/emtricitabine-treated patients the presence of M184V (without other NRTI RAMs) was not associated with virological failure. CONCLUSION: Unboosted-atazanavir containing regimens were efficacious (with uncommon virological failures) and well-tolerated (with improvements in lipid profile over time) treatments in HIV-positive patients. Isolated M184V in lamivudine/emtricitabine recipients was not associated with higher failure rates supporting the use of functional ATV-based dual therapies as maintenance strategies.

Tenofovir plasma concentrations according to companion drugs: a cross-sectional study of HIV-positive patients with normal renal function.

As the risk of tenofovir-associated renal toxicity has been found to be proportional to the drug plasma concentration, our aim was to measure the determinants of tenofovir plasma exposure in HIV-positive patients with normal renal function. A cross-sectional analysis was conducted in HIV-positive patients chronically receiving tenofovir-containing highly active antiretroviral therapies (HAARTs). Patients on tenofovir-containing antiretroviral regimens, presenting 22 to 26 h after drug intake, having estimated glomerular filtration rates above 60 ml/min, reporting high adherence to antiretroviral medications (above 95% of the doses), and signing a written informed consent were included. Plasma tenofovir concentrations were measured through a validated high-performance liquid chromatography-mass spectrometry (HPLC/LC-MS) method. The tenofovir trough concentrations in 195 patients (median, 50 ng/ml, and interquartile range, 35 to 77 ng/ml) were significantly associated with the estimated glomerular filtration rate, body mass index, and third-drug class (protease-containing versus protease-sparing regimens) (with the highest exposure in unboosted-atazanavir recipients). The results of multivariate analysis showed that the third-drug class and the weight/creatinine ratio were independent predictors of tenofovir trough concentrations. This cross-sectional study shows that tenofovir trough concentrations are predicted by the weight/creatinine ratio and by the coadministered antiretrovirals, with protease inhibitors (whether boosted or unboosted) being associated with the highest plasma exposure. These data, previously available in healthy subjects or for some drugs only, could be useful for designing strategies to manage tenofovir-associated toxicity, since this toxicity has been reported to be dose dependent.