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Objectives: To evaluate the impact of a treatment switch to dolutegravir plus lamivudine on the soluble inflammatory biomarkers of HIV-infected patients treated in a real-life setting. Materials and methods: This was a longitudinal study that enrolled virologically-suppressed patients on stable 3-drug ART who switched at baseline to dolutegravir + lamivudine (2DR-group), based on the clinician's decision, or maintained triple therapy (3DR-group). Subjects in the 3DR-group were matched with those in the 2DR-group for age, gender and type of anchor drug. Plasma levels of interleukin-6 (IL-6), I-FABP, D-dimer and C-reactive protein (CRP) were quantified by a microfluidic ultrasensitive ELISA assay at baseline and at 48 weeks. Results: Overall 208 subjects were enrolled: 101 in the 2DR-group and 107 in the 3DR-group. At baseline, biomarker levels were comparable between groups. The differences in mean log 10 change from baseline to 48 weeks between groups (2DR versus 3DR) were: IL-6 (pg/L) -0.051(95% CI -0.115/0.009) versus 0.004 (95% CI -0.046/0.054) (p = 0.159); I-FABP (pg/mL), -0.088 (95% CI -0.14/-0.041) versus 0.033 (95%CI -0.007/0.072) (p < 0.001); D-dimer (pg/mL), -0.011(95% CI-0.055/0.033) versus -0.021 (95% CI -0.071/0.030) (p = 0.780) and CRP (pg/mL), -0.028 (95%CI -0.118/0.063) versus 0.118 (95% CI 0.024/0.211) (p = 0.028). Conclusions: At 1 year, switching to a dolutegravir plus lamivudine dual regimen in this setting showed a favorable trend for two biomarkers analyzed, i.e., I-FABP and CRP, as compared to continuing a triple therapy. These results add important new data in support of the safety of this approach in terms of its effect on the inflammatory milieu.

Background: Clinical trials have demonstrated noninferior viral suppression rates of selected 2-drug regimens (2DRs) over standard 3-drug regimens (3DRs). However, the effect of simplification to 2DRs on HIV-1 reservoir remains to be fully assessed., Setting: Retrospective analyses of samples of virologically suppressed people living with HIV remaining on the same 3DRs or switching to DTG + 3TC or ATV/r + 3TC 2DRs., Methods: Whole blood samples were collected at enrollment and after 48 weeks. Total HIV-1 DNA (tDNA) and intact HIV-1 DNA (iDNA) were quantified by droplet digital polymerase chain reaction and intact proviral DNA assay, respectively. Statistical analysis was performed to identify associations among variables, and multiple linear regression was used to analyze potential predictors of tDNA and iDNA changes over time., Results: Forty-seven individuals were switched to DTG + 3TC 2DR (N = 23) and ATV/r + 3TC 2DR (N = 24), while 18 remained on 3DRs. tDNA did not change either in the overall population or in the 3DR and 2DR groups. iDNA decreased significantly in the whole data set and in the overall 3DR and 2DR groups ( P = 0.001, P = 0.039 and P = 0.009, respectively). iDNA, but not tDNA, was inversely correlated with the time of viral suppression ( P = 0.002) and time under antiretroviral therapy ( P = 0.006). Higher nadir CD4 + T-cell counts ( P = 0.001) and lower zenith viral load ( P = 0.02) showed an association with the decrease of iDNA, but not with tDNA., Conclusions: Both tDNA and iDNA dynamics supported noninferior efficacy of 2DRs over 3DRs. iDNA could be more informative than tDNA in analyzing the dynamics of the HIV-1 reservoir under different treatment strategies., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Aim of this study is to assess the impact of doravirine (DOR)-based regimens on cardiovascular risk in treatment-experienced people living with HIV (PLWHIV). We retrospectively analyzed a cohort of 40 treatment-experienced PLWHIV switching to a DOR-based three-drug regimen, evaluating 10-year risk of manifesting clinical cardiovascular diseases (CD) through the Framingham Risk Score at baseline, 12, and 24 weeks of follow-up. At baseline, median predicted 10-year risk of cardiovascular disease (10Y-CD) was 8.0% (interquartile range 4.0-13.0). After 12 weeks, we observed a significant reduction in 10Y-CD (mean decrease -2.21, p  = .012); similarly, we observed a nonsignificant reduction at week 24 ( p  = .336). Regarding metabolic parameters, after 24 weeks we observed a significant reduction in total cholesterol (median change -8.8 mg/dL, p  = .018), low-density lipoprotein cholesterol (median -9.5 mg/dL, p  = .007), and triglycerides (median -19.8 mg/dL, p  < .001). Our results show a favorable metabolic impact of DOR-based regimens along with a promising reduction in 10-year risk of cardiovascular disease.

Little is known about long-term maintenance of virologic suppression in HIV migrants in Italy. The study aims to compare virologic failure rates and associated factors among antiretroviral therapy (ART)-naïve migrants and natives enrolled in the ARCA database since 2007 who achieved virologic suppression within 18 months from the beginning of the ART. Kaplan-Meier method assessed the probability of virologic suppression and failure. Cox regression model was used for multivariate analysis. Of 2515 patients, 2020 (80.3%) were Italian, 286 (10.6%) migrants from low-income countries, of whom 201 (75.0%) from Africa, and 227 (9.0%) from high-income-countries. The median follow-up was 4.5 years (IQR 2.5-7). No difference was observed in the time of achievement of virological suppression in the three groups (log-rank: p  = 0.5687). Higher probability of virologic failure was observed in Africans compared to Italians, to patients from high-income-countries and from low-income-countries other than Africans (Log-rank =  p  < 0.001). In the adjusted analysis, a higher virologic failure risk was found in Africans only compared to Italians. [HR 4.01; 95% CI 2.44-6.56, p  < 0.001]. In Italy, African migrants are less likely to maintain virologic suppression compared to natives and other migrants. Targeted interventions could be needed for foreigners, especially for Africans.

We tried to investigate and compare the safety of a dual therapy (DT) with dolutegravir+lamivudine (DTG +3TC) versus bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). We performed a retrospective analysis in a cohort of virologically suppressed HIV+ pts switching to DT or BIC in our center. Primary endpoint was to evaluate time to treatment discontinuation (TD) for any cause. Survival analysis was employed to determine time to TD and its predictors were analyzed by Cox regression. Moreover, we collected viro-immunological parameters as well as markers of renal function and lipid profile at baseline and after 24 weeks and assessed changes through nonparametric tests. We analyzed 476 patients: 350 starting a DT and 126 starting BIC. Overall, we registered 21 TD: 15 in the DT group during 170 patient-years of follow-up (PYFU) (a rate of 8.8 per 100 PYFU) and 6 in the BIC one during 48 PYFU (12.5 per 100 PYFU). Estimated probabilities of maintaining study regimen after 24 weeks were 95.5% [standard deviation (SD) ±1.1] in the DT group and 94.9% (SD ±2.0) in the BIC group, with no significant differences between them (log-rank p  = .639). Concerning metabolic profile, in the DT group, after 24 weeks, triglycerides decreased significantly (median change -14 mg/dL, p  < .001), whereas high-density lipoprotein cholesterol increased (+3 mg/dL, p  = .031). In the BIC group, meanwhile, we observed a significant decrease in low-density lipoprotein cholesterol after 24 weeks (-13 mg/dL, p  = .026). Both optimization strategies showed high tolerability in the short term in experienced pts, with few differences between them. Further studies are needed to properly assess the matter.

The GEMINI trials have showed that the two drugs regimen of dolutegravir+lamivudine (DTG +3TC) was noninferior to a three-drug regimen as a first line regimen for treatment-naive people living with HIV. The aim of our study was to confirm, in a real-life setting, the efficacy of this regimen. We conducted a retrospective, observational study enrolling treatment-naive patients starting a first-line regimen with lamivudine plus dolutegravir. We evaluated the virological efficacy and the immunological and metabolic profiles. Changes from baseline were evaluated through linear-mixed models for repeated measures. Linear regression analyses were performed to explore variables associated to significant changes in laboratory parameters. We analyzed a total of 20 patients: 15 (75%) were men with a median age of 34.5 years. During a cumulative time of 15.4 patients years of follow up (PYFU), we did not observe any adverse event or treatment discontinuation and all patients achieved virological suppression in the first 6 months from treatment initiation. Increase in CD4 + cells was significant at both week 24 ( p  = .003) and week 48 ( p  = .007) of follow-up. Moreover, CD4/CD8 ratio also significantly improved [median increase of +0.22 ( p  = .028) after 48 weeks of follow-up]. As to metabolic parameters, we observed no significant changes in total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. In a subgroup of 11 patients, we further investigate HIV-1 DNA variations. Our results are in line with the findings of the GEMINI trials, confirming the efficacy and safety of DTG +3TC in treatment-naive patients.

Everyday functioning (EF) impairment is frequent in people living with HIV (PLWH). Our aim was to better explore EF and its association with PLWH cognition, by administering both the IADL scale, the most common functional scale, and a new and ecologic multi-domain (communication and financial skills) tool to measure EF as the University of California San Diego (UCSD) Performance-Based Skills Assessment-Brief Version (UPSA-B). Eighty-five PLWH on cART with very good immunological condition and 23 age- and education-matched healthy controls (HC) were enrolled. PLWH underwent a standardized neuropsychological battery plus IADL, and cognitive impairment was defined according to Frascati criteria. Both groups underwent the UPSA-B. Only 6 subjects (7%) were affected by cognitive impairment (asymptomatic profile). While IADL score was at ceiling for all patients, the UPSA-B total score was significantly worse in PLWH when compared with HC [mean 82.1 (SD 9.3) vs 89.2 (SD 6.2); p < 0.001]. At communication subtest, PLWH group and HC were significantly different (p = 0.002), while no difference emerged at financial skills (p = 0.096). Higher score at UPSA-B was independently associated with better global cognitive performance (composite Z-score) (β 7.79; p < 0.001). Also considering each single cognitive domain, UPSA-B performance (both total and at subtests) confirmed the association with neurocognitive performance. In conclusion, UPSA-B seems to better discriminate EF impairment than IADL in PLWH, and it was associated with cognitive functions, also in the absence of symptomatic cognitive impairment. Thus, it appears a promising tool in the context of HIV infection to avoid misdiagnosis and to better detect also mild EF.

Objectives: To assess the impact of switching to dolutegravir plus lamivudine maintenance therapy on the HIV cellular reservoir size., Patients and Methods: This was a prospective, longitudinal, matched, controlled study. We enrolled virologically suppressed patients on stable three-drug ART who switched at baseline (BL) to dolutegravir/lamivudine (DT group) or maintained triple therapy (TT group); subjects in the TT group were matched 1:1 with those in the DT group according to age, gender, years since HIV diagnosis, years on ART and anchor drug. Total blood-associated HIV DNA levels were assessed by droplet digital PCR at BL and after 48 weeks (T48). Results were expressed as log10 HIV DNA copies/106 leucocytes., Results: We enrolled 40 patients in the DT group and 40 in the TT group; the two groups were homogeneous for all main characteristics except nadir CD4 cell count. At BL, HIV DNA levels were comparable between the DT and TT groups: 2.27 (IQR 1.97-2.47) and 2.26 (IQR 2.05-2.61) log10 HIV DNA copies/106 leucocytes, respectively. Change in HIV DNA load from BL to T48 was -0.105 (IQR -0.384 to 0.121, P = 0.041) in the DT group and -0.132 (IQR -0.362 to 0.046, P = 0.005) in the TT group, with a comparable decline observed between the two groups (P = 0.821). A higher HIV DNA decline was associated with higher BL CD4/CD8 ratio., Conclusions: Maintenance therapy with dolutegravir/lamivudine had the same impact as the triple regimen on HIV DNA levels after 48 weeks of treatment. These data seem to support the effectiveness of a dolutegravir/lamivudine dual regimen in controlling the magnitude of the cellular reservoir (www.clinicaltrials.gov, number NCT02836782)., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: An increase in pretreatment drug resistance (PDR) to first-line antiretroviral therapy (ART) in low-income countries has been recently described. Herein we analyse the prevalence of PDR and risk of virological failure (VF) over time among migrants to Italy enrolled in ARCA., Methods: HIV-1 sequences from ART-naive patients of non-Italian nationality were retrieved from ARCA database from 1998 to 2017. PDR was defined by at least one mutation from the reference 2009 WHO surveillance list., Results: Protease/reverse transcriptase sequences from 1,155 patients, mainly migrants from sub-Saharan Africa (SSA; 42%), followed by Latin America (LA; 25%) and Western countries (WE; 21%), were included. PDR was detected in 8.6% of sequences (13.1% versus 5.8% for B and non-B strains, respectively; P<0.001). 2.1% of patients carried a PDR for protease inhibitors (PIs; 2.1% versus 2.3%; P=0.893), 3.9% for nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs; 6.8% versus 2.1%; P<0.001) and 4.3% for non-nucleoside/nucleotide reverse transcriptase inhibitors (NNRTIs; 6.3% versus 3.1%; P=0.013). Overall, prevalence of PDR over the years remained stable, while it decreased for PIs in LA (P=0.021) and for NRTIs (P=0.020) among migrants from WE. Having more than one class of PDR (P=0.015 versus absence of PDR), higher viral load at diagnosis (P=0.008) and being migrants from SSA (P=0.001 versus WE) were predictive of VF, while a recent calendar year of diagnosis (P<0.001) was protective for VF., Conclusions: PDR appeared to be stable over the years in migrants to Italy enrolled in ARCA; however, it still remains an important cause of VF together with viral load at diagnosis.

Background: Pre-cART (combined antiretroviral therapy) plasma viral load >500,000 copies/ml has been associated with a lower probability of achieving virological suppression, while few data about its role on maintenance of virological suppression are available. In this study we aimed to clarify whether high levels of pre-cART viraemia are associated with virological rebound (VR) after virological suppression., Methods: HIV-infected individuals who achieved virological suppression after first-line cART were included. VR was defined as the first of two consecutive viraemia >50 copies/ml (VR50) or, in an alternative analysis, >200 copies/ml (VR200). The impact of pre-cART viraemia on the risk of VR was evaluated by survival analyses., Results: Among 5,766 patients included, 59.2%, 31.4%, 5.2% and 4.2% had pre-cART viraemia ≤100,000, 100,001-500,000, 500,001-1,000,000 and >1,000,000 copies/ml, respectively. Patients with pre-cART viraemia levels >1,000,000 copies/ml had the highest probability of VR (>1,000,000; 500,000-1,000,000; 100,000-500,000; <100,000 copies/ml; VR50: 28.4%; 24.3%; 17.6%; 13.8%, P<0.0001; VR200: 14.4%; 11.1%; 7.2%; 7.6%; P=0.009). By Cox multivariable analyses, patients with pre-cART viraemia >500,000 and >1,000,000 copies/ml showed a significantly higher risk of VR regardless of the VR end point used. No difference in the risk of VR was found between patients with pre-cART viraemia ranging 500,000-1,000,000 copies/ml and those with pre-cART viraemia >1,000,000 copies/ml, regardless of the VR end point used., Conclusions: Pre-cART plasma viral load levels >500,000 copies/ml can identify fragile patients with poorer chance of maintaining virological control after an initial response. An effort in defining effective treatment strategies is mandatory for these patients that remain difficult to treat.

Background: The influence of HIV-1 co-receptor usage on the course of therapy in subjects fully responding to ART has been poorly investigated., Objectives: To explore the relationship between co-receptor tropism and cellular reservoir size, residual viremia and subsequent virological outcome in ART-treated patients with HIV-1 RNA stable <50 copies/mL., Study Design: Viral co-receptor usage was predicted by viral env DNA sequencing with geno2pheno interpretation (FPR20%) and classified as R5 and non-R5. Total blood-associated HIV-1 DNA levels (log 10 copies/10 6 leukocytes) were measured by qRT-PCR (5'LTR). Residual plasma viremia was categorized as detectable (1-49 cps/mL) or undetectable (<1 copy/mL). Virological rebounds (any HIV-1 RNA >50 copies/mL) were evaluated over 96 weeks., Results: The study included 116 subjects. Patients with R5 virus (n = 59) and non-R5 virus (n = 57) were homogeneous for the main characteristics except for the lower nadir CD4 cell count in the non-R5 group. Patients with non-R5 variants showed higher levels of HIV-1 DNA as compared to patients with R5 virus: mean 2.47 (95% CI 2.37-2.56) vs 2.17 (2.08-2.26) (p < 0.001). Moreover, a higher proportion of patients in the non-R5 group displayed detectable residual viremia with respect to the R5-group (54.4% vs 32.2%, p = .016). Detectable residual viremia was found to be significantly associated with viral rebounds., Conclusion: The presence of non-R5 viral DNA variants is related to a higher probability of residual viremia and to a larger size of the cellular viral reservoir in this setting. These data highlight a potential role of viral tropism in the monitoring of HIV-1 infection in virologically controlled subject., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Few data are available about efficacy and durability of simplification from multi-tablet antiretroviral regimens to co-formulated efavirenz (EFV)/emtricitabine (FTC)/tenofovir (TDF) versus rilpivirine (RPV)/FTC/TDF in virologically suppressed HIV-1-infected patients., Methods: We retrospectively analysed HIV-infected patients with HIV RNA <50 copies/ml switching to co-formulated EFV/FTC/TDF or RPV/FTC/TDF at five Italian centres. Patients were followed from time of switch until regimen discontinuation or a maximum of 3-years follow-up. Time to treatment discontinuation (TD) and virological failure (VF; defined as two consecutive HIV RNA >50 copies/ml or a single determination >1,000 copies/ml) and their predictors were investigated., Results: 1,560 patients were reviewed of which 1,097 (70%) switched to EFV/FTC/TDF and 463 (30%) to RPV/FTC/TDF. During follow-up, VF and TD occurred in 44 (4%) and 242 (22%) patients in EFV/FTC/TDF and in 29 (6%) and 50 (11%) patients in RPV/FTC/TDF, respectively. The 3-year estimated probability of remaining free from VF was 96.2% with EFV/FTC/TDF versus 92.7% with RPV/FTC/TDF (P=0.003). At multivariate analysis, regimen type (EFV/FTC/TDF versus RPV/FTC/TDF aHR 0.24; P=0.004) and time of virological suppression (aHR 0.85; P=0.048) were the only independent predictors of VF. The estimated 3-year probability of remaining free from TD was 77.4% with EFV/FTC/TDF versus 88.4% with RPV/FTC/TDF (P=0.001). Predictors of TD were female sex, switching from PI-based regimens, older age, shorter time of virological suppression and regimen type (EFV/FTC/TDF versus RPV/FTC/TDF aHR 2.48; P<0.001). RPV/FTC/TDF showed a safer lipid profile and a greater increase in creatinine., Conclusions: Both regimens showed good safety and efficacy in this real-life setting, although switch to RPV/FTC/TDF seemed better tolerated while EFV/FTC/TDF was associated with a lower probability of VF.

Objectives: The AtLaS-M randomized trial showed that in patients with HIV-1 RNA <50 copies/mL on atazanavir/ritonavir + two NRTIs, switching to a dual therapy with atazanavir/ritonavir+lamivudine had superior efficacy as compared with continuing the previous triple therapy. This substudy was designed to evaluate at 48 weeks the impact of the dual therapy versus the three-drug atazanavir/ritonavir-based therapy on the HIV-1 cellular reservoir as reflected by the quantification of blood-associated HIV-1 DNA levels., Methods: In a representative subset of 201 of 266 randomized patients (104 in the dual-therapy arm and 97 in the triple-therapy arm) total HIV-1 DNA levels in whole blood at baseline and after 48 weeks and factors associated with the HIV-1 DNA levels were evaluated., Results: The mean baseline HIV-1 DNA levels (2.47 log 10 copies/10 6 leucocytes) were comparable between arms. A significant mean decrease between baseline and week 48 was observed: -0.069 log 10 copies/10 6 leucocytes in the dual-therapy arm ( P  =   0.046) and -0.078 in the triple-therapy arm ( P  =   0.011); the mean difference between arms was -0.009 ( P  =   0.842). Nadir CD4 count was inversely correlated with baseline HIV-1 DNA ( P  =   0.009); longer duration of ART and lower nadir CD4 correlated with a less prominent HIV-1 DNA decrease (both P  <   0.005). Higher baseline HIV-1 DNA was associated with residual viraemia at week 48 ( P  =   0.031)., Conclusions: When compared with continuing three-drug therapy, atazanavir/ritonavir+lamivudine dual therapy resulted in a similar decline in HIV-1 DNA levels in patients with sustained virological suppression. These data support the safety of this simplified treatment strategy in terms of its effect on the cellular HIV-1 reservoir., (© The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: The integrase inhibitor raltegravir has been used to intensify antiretroviral therapy in patients with undetectable plasma HIV-1RNA, resulting in variable perturbation of HIV-1 nucleic acids levels in peripheral blood., Objectives: We aimed at monitoring residual plasma HIV-1RNA and total cellular HIV-1DNA in virologically suppressed patients switching to raltegravir-based regimens., Study Design: Fifty-eight subjects on protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens, with plasma HIV-1RNA levels <40 copies/ml for ≥6 months and CD4 counts >200cells/μl for ≥12 months were enrolled. Thirty-four patients were from the treatment simplification RASTA randomized study switching standard therapy to a raltegravir-based regimen (RASTA group), while 24 continued a PI or NNRTI based-regimen (controls). Residual plasma HIV-1RNA (5-40copies/mL) and HIV-1DNA were assessed at 0, 24 and 48 weeks., Results: At week 0 (W0), HIV-1DNA was detected in all patients while at W48 it was detectable in 82.4% of the RASTA group vs 100% of controls (p=0.03). There was a significant decline of HIV-1DNA at W48 in the RASTA group (mean change from baseline -0.21 [95% CI -0.41; -0.01] log 10 copies/10 6 CD4; p=0.03) but not in controls. Ultrasensitive HIV-1RNA was detectable at baseline in 50% of RASTA group vs 67% of controls and at W48 in 32.4% vs 42%, respectively. No differences were found between HIV-1RNA levels at baseline and W48 within and between groups., Conclusions: Switching successful therapy to raltegravir-based regimens may be associated with a decrease of the HIV-1 reservoir, as measured by peripheral blood cellular HIV-1DNA levels., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: HIV-1 drug resistance can be measured with phenotypic drug-resistance tests. However, the output of these tests, the resistance factor (RF), requires interpretation with respect to the in vivo activity of the tested variant. Specifically, the dynamic range of the RF for each drug has to be divided into a suitable number of clinically meaningful intervals., Methods: We calculated a susceptible-to-intermediate and an intermediate-to-resistant cutoff per drug for RFs predicted by geno2pheno[resistance]. Probability densities for therapeutic success and failure were estimated from 10,444 treatment episodes. The density estimation procedure corrects for the activity of the backbone drug compounds and for therapy failure without drug resistance. For estimating the probability of therapeutic success given an RF, we fit a sigmoid function. The cutoffs are given by the roots of the third derivative of the sigmoid function., Results: For performance assessment, we used geno2pheno[resistance] RF predictions and the cutoffs for predicting therapeutic success in 2 independent sets of therapy episodes. HIVdb was used for performance comparison. On one test set (n = 807), our cutoffs and HIVdb performed equally well receiver operating characteristic curve [(ROC)-area under the curve (AUC): 0.68]. On the other test set (n = 917), our cutoffs (ROC-AUC: 0.63) and HIVdb (ROC-AUC: 0.65) performed comparatively well., Conclusions: Our method can be used for calculating clinically relevant cutoffs for (predicted) RFs. The method corrects for the activity of the backbone drug compounds and for therapy failure without drug resistance. Our method's performance is comparable with that of HIVdb. RF cutoffs for the latest version of geno2pheno[resistance] have been estimated with this method.

Background: Combination ART (cART)-related toxicities and costs have prompted the need for treatment simplification. The ATLAS-M trial explored 48 week non-inferior efficacy of simplification to atazanavir/ritonavir  +  lamivudine versus maintaining three-drug atazanavir/ritonavir-based cART in virologically suppressed patients., Methods: We performed an open-label, multicentre, randomized, non-inferiority study, enrolling HIV-infected adults on atazanavir/ritonavir + two NRTIs, with stable HIV-RNA <50 copies/mL and CD4 + >200 cells/mm 3 . Main exclusion criteria were hepatitis B virus coinfection, past virological failure on or resistance to study drugs, recent AIDS and pregnancy. Patients were randomly assigned 1:1 to either switch to 300 mg of atazanavir/100 mg of ritonavir once daily and 300 mg of lamivudine once daily (atazanavir/ritonavir + lamivudine arm) or to continue the previous regimen (atazanavir/ritonavir + two NRTIs arm). The primary study outcome was the maintenance of HIV-RNA <50 copies/mL at week 48 of the ITT-exposed (ITT-e) analysis with switch = failure. The non-inferiority margin was 12%. This study is registered at ClinicalTrials.gov, number NCT01599364., Results: Between July 2011 and June 2014, 266 patients were randomized (133 to each arm). After 48 weeks, the primary study outcome was met by 119 of 133 patients (89.5%) in the atazanavir/ritonavir + lamivudine arm and 106 of 133 patients (79.7%) in the atazanavir/ritonavir + two NRTIs arm [difference atazanavir/ritonavir + lamivudine versus atazanavir/ritonavir + two NRTIs arm: +9.8% (95% CI + 1.2 to + 18.4)], demonstrating non-inferiority and superior efficacy of the atazanavir/ritonavir + lamivudine arm. Virological failure occurred in two (1.5%) patients in the atazanavir/ritonavir + lamivudine arm and six (4.5%) patients in the atazanavir/ritonavir + two NRTIs arm, without resistance selection. A similar proportion of adverse events occurred in both arms., Conclusions: Treatment simplification to atazanavir/ritonavir + lamivudine showed non-inferior efficacy (superiority on post-hoc analysis) and a comparable safety profile over continuing atazanavir/ritonavir + two NRTIs in virologically suppressed patients., (© The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: The aim of the study was to explore relationships between self-reported adherence, antiretroviral drug concentration measurement (TDM) and self-reported symptoms., Methods: We systematically administered to human immunodeficiency (HIV)-infected outpatients a questionnaire evaluating measures of self-reported adherence (missing doses during last week, deviations from the prescribed timing of therapy, self-initiated discontinuations for > 24 or 48 h, exhausting drugs and present sense of how patients are taking therapy) and a panel of referred symptoms (a symptom score was built summing self-reported scores for each listed symptom). We selected patients who completed the questionnaire and also had a TDM (mainly reflecting adherence in the past few days or weeks), thus comparing these two tools as measures of adherence., Results: A total of 130 patients (64.6% males, median age 44 years, 76.2% with HIV RNA < 50 copies/ml, median CD4 540 cells/μl) were included. Mean self-reported adherence (on a 0-100 visual analogue scale) was 80% (standard deviation, 18.7). Drug concentration was subtherapeutic in 16 patients (12.3%), of which 7 (5.4%) had undetectable drug levels (< 0.05 mg/L). Of these last seven patients, five (71.4%) reported an adherence below 80%. In a multivariable analysis, females and patients with undetectable drug levels (mean change -18.43%, 95% confidence intervals (CIs) -31.83 to -5.03, p = 0.007) showed a lower self-reported adherence, while those with HIV RNA < 50 copies/ml showed a higher adherence. Lower self-reported adherence (odds ratio 0.62 per 10% increase, 95% CI = 0.43-0.89, p = 0.009) and longer time from last drug intake were independently related to the development of undetectable drug levels. We also found that a higher symptom score was associated with a lower self-reported adherence and with a higher proportion of undetectable drug levels., Conclusions: Self-reported adherence and TDM showed a correlation and seemed to be comparable tools for adherence estimation. Self-reported symptoms were associated with lower adherence and undetectable drug levels.

Objective: To evaluate the Fibrosis (FIB)-4 index as a predictor of major liver-related events (LRE) and liver-related death (LRD) in human immunodeficiency virus (HIV) type-1 patients initiating combination antiretroviral therapy (cART)., Design: Retrospective analysis of a prospective cohort study., Setting: Italian HIV care centers participating to the ICONA Foundation cohort., Participants: Treatment-naive patients enrolled in ICONA were selected who: initiated cART, had hepatitis C virus (HCV) serology results, were HBsAg negative, had an available FIB-4 index at cART start and during follow up., Methods: Cox regression models were used to determine the association of FIB4 with the risk of major LRE (gastrointestinal bleeding, ascites, hepatic encephalopathy, hepato-renal syndrome or hepatocellular carcinoma) or LRD., Results: Three-thousand four-hundred seventy-five patients were enrolled: 73.3% were males, 27.2% HCV seropositive. At baseline (time of cART initiation) their median age was 39 years, had a median CD4+ T cell count of 260 cells/uL, and median HIV RNA 4.9 log copies/mL, 65.9% had a FIB-4 <1.45, 26.4% 1.45-3.25 and 7.7% >3.25. Over a follow up of 18,662 person-years, 41 events were observed: 25 major LRE and 16 LRD (incidence rate, IR, 2.2 per 1,000 PYFU [95% confidence interval, CI 1.6-3.0]). IR was higher in HCV seropositives as compared to negatives (5.9 vs 0.5 per 1,000 PYFU). Higher baseline FIB-4 category as compared to <1.45 (FIB-4 1.45-3.25: HR 3.55, 95% CI 1.09-11.58; FIB-4>3.25: HR 4.25, 1.21-14.92) and time-updated FIB-4 (FIB-4 1.45-3.25: HR 3.40, 1.02-11.40; FIB-4>3.25: HR 21.24, 6.75-66.84) were independently predictive of major LRE/LRD, after adjusting for HIV- and HCV-related variables, alcohol consumption and type of cART., Conclusions: The FIB-4 index at cART initiation, and its modification over time are risk factors for major LRE or LRD, independently of infection with HCV and could be used to monitor patients on cART.

Background: The aim of the study was to explore how viral resistance and antiretroviral central nervous system (CNS) penetration could impact on cognitive performance of HIV-infected patients., Methods: We performed a multicentre cross-sectional study enrolling HIV-infected patients undergoing neuropsychological testing, with a previous genotypic resistance test on plasma samples. CNS penetration-effectiveness (CPE) scores and genotypic susceptibility scores (GSS) were calculated for each regimen. A composite score (CPE-GSS) was then constructed. Factors associated with cognitive impairment were investigated by logistic regression analysis., Results: A total of 215 patients were included. Mean CPE was 7.1 (95% CI 6.9, 7.3) with 206 (95.8%) patients showing a CPE≥6. GSS correction decreased the CPE value in 21.4% (mean 6.5, 95% CI 6.3, 6.7), 26.5% (mean 6.4, 95% CI 6.1, 6.6) and 24.2% (mean 6.4, 95% CI 6.2, 6.6) of subjects using ANRS, HIVDB and REGA rules, respectively. Overall, 66 (30.7%) patients were considered cognitively impaired. No significant association could be demonstrated between CPE and cognitive impairment. However, higher GSS-CPE was associated with a lower risk of cognitive impairment (CPE-GSSANRS odds ratio 0.75, P=0.022; CPE-GSSHIVDB odds ratio 0.77, P=0.038; CPE-GSSREGA odds ratio 0.78, P=0.038). Overall, a cutoff of CPE-GSS≥5 seemed the most discriminatory according to each different interpretation system., Conclusions: GSS-corrected CPE score showed a better correlation with neurocognitive performance than the standard CPE score. These results suggest that antiretroviral drug susceptibility, besides drug CNS penetration, can play a role in the control of HIV-associated neurocognitive disorders.

Objectives: Maraviroc has been shown to be effective in patients harbouring CCR5-tropic HIV-1. While this CCR5 antagonist has initially been used in salvage therapy, its excellent safety profile makes it ideal for antiretroviral treatment simplification strategies in patients with suppressed plasma viraemia. The aim of this study was to compare HIV-1 tropism as detected in baseline plasma RNA and peripheral blood mononuclear cell (PBMC) DNA prior to first-line therapy and to analyse tropism evolution while on successful treatment., Methods: HIV-1 tropism was determined using triplicate genotypic testing combined with geno2pheno[coreceptor] analysis at a 10% false positive rate in 42 patients. Paired pre-treatment plasma RNA and PBMC DNA and two subsequent PBMC DNA samples (the first obtained after reaching undetectable plasma HIV-1 RNA and the second after at least 2 years of suppression of plasma viraemia) were evaluated., Results: Coreceptor tropism was completely concordant in paired pre-treatment RNA and DNA, with 26.2% of HIV-1 sequences predicted to be non-CCR5-tropic. During follow-up, coreceptor tropism switches were detected in 4 (9.5%) patients without any preferential direction. Although false positive rate discrepancies within triplicates were common, the rate of discordance of coreceptor tropism assignment among triplicate results in this mostly CCR5-tropic dataset was only 2.1%, questioning the added value of triplicate testing compared with single testing., Conclusions: HIV-1 coreceptor tropism changes during virologically successful first-line treatment are infrequent. HIV-1 DNA analysis may thus support the choice of a CCR5 antagonist in treatment switch strategies; however, maraviroc treatment outcome data are required to confirm this option.

HIV-1 drug resistance represents a major obstacle to infection and disease control. This retrospective study analyzes trends and determinants of resistance in antiretroviral treatment (ART)-exposed individuals across 7 countries in Europe. Of 20 323 cases, 80% carried at least one resistance mutation: these declined from 81% in 1997 to 71% in 2008. Predicted extensive 3-class resistance was rare (3.2% considering the cumulative genotype) and peaked at 4.5% in 2005, decreasing thereafter. The proportion of cases exhausting available drug options dropped from 32% in 2000 to 1% in 2008. Reduced risk of resistance over calendar years was confirmed by multivariable analysis.

We investigated the rates of lipodystrophy events, according to mitochondrial DNA haplogroup, in 187 patients starting combination antiretroviral therapy and following it. Incidence rates of lipoatrophy and fat accumulation were 8.2 and 4.8 per 100 person-years of follow-up, respectively. In multivariable models, patients with haplogroup K were at higher risk of any lipodystrophy [adjusted relative risk (aRR) 4.02, P = 0.0009], lipoatrophy (competing-risk aRR 2.42, P = 0.09; cause-specific aRR 2.99, P = 0.031), and fat accumulation (competing-risk aRR, 2.63, P = 0.11; cause-specific aRR 5.27, P = 0.019) than those with haplogroup H. Mitochondrial haplogroups may explain part of the genetic predisposition to lipodystrophy during combination antiretroviral therapy.

Objective: The potential for changing HIV-1 virulence has significant implications for the AIDS epidemic, including changing HIV transmission rates, rapidity of disease progression, and timing of ART. Published data to date have provided conflicting results., Design: We conducted a meta-analysis of changes in baseline CD4(+) T-cell counts and set point plasma viral RNA load over time in order to establish whether summary trends are consistent with changing HIV-1 virulence., Methods: We searched PubMed for studies of trends in HIV-1 prognostic markers of disease progression and supplemented findings with publications referenced in epidemiological or virulence studies. We identified 12 studies of trends in baseline CD4(+) T-cell counts (21, 052 total individuals), and eight studies of trends in set point viral loads (10 ,785 total individuals), spanning the years 1984-2010. Using random-effects meta-analysis, we estimated summary effect sizes for trends in HIV-1 plasma viral loads and CD4(+) T-cell counts., Results: Baseline CD4(+) T-cell counts showed a summary trend of decreasing cell counts [effect = -4.93  cells/μl per year, 95% confidence interval (CI) -6.53 to -3.3]. Set point viral loads showed a summary trend of increasing plasma viral RNA loads (effect = 0.013  log(10)  copies/ml per year, 95% CI -0.001 to 0.03). The trend rates decelerated in recent years for both prognostic markers., Conclusion: Our results are consistent with increased virulence of HIV-1 over the course of the epidemic. Extrapolating over the 30 years since the first description of AIDS, this represents a CD4(+) T cells loss of approximately 148  cells/μl and a gain of 0.39  log(10)  copies/ml of viral RNA measured during early infection. These effect sizes would predict increasing rates of disease progression, and need for ART as well as increasing transmission risk.

Background and Objectives: Guidelines indicate a plasma HIV-1 RNA load of 500-1000 copies/mL as the minimal threshold for antiretroviral drug resistance testing. Resistance testing at lower viral load levels may be useful to guide timely treatment switches, although data on the clinical utility of this remain limited. We report here the influence of viral load levels on the probability of detecting drug resistance mutations (DRMs) and other mutations by routine genotypic testing in a large multicentre European cohort, with a focus on tests performed at a viral load <1000 copies/mL., Methods: A total of 16 511 HIV-1 reverse transcriptase and protease sequences from 11 492 treatment-experienced patients were identified, and linked to clinical data on viral load, CD4 T cell counts and antiretroviral treatment history. Test results from 3162 treatment-naive patients served as controls. Multivariable analysis was employed to identify predictors of reverse transcriptase and protease DRMs., Results: Overall, 2500/16 511 (15.14%) test results were obtained at a viral load <1000 copies/mL. Individuals with viral load levels of 1000-10000 copies/mL showed the highest probability of drug resistance to any drug class. Independently from other measurable confounders, treatment-experienced patients showed a trend for DRMs and other mutations to decrease at viral load levels <500 copies/mL., Conclusions: Genotypic testing at low viral load may identify emerging antiretroviral drug resistance at an early stage, and thus might be successfully employed in guiding prompt management strategies that may reduce the accumulation of resistance and cross-resistance, viral adaptive changes, and larger viral load increases.

An investigation was undertaken to determine whether specific pol mutations hinder long-term immune recovery regardless of virological response. In total, 826 patients with >50 HIV RNA copies/ml, who underwent genotypic resistance testing between 1 January 2000 and 31 December 2003 after >3 years of antiretroviral treatment, and were followed up for >3 years after genotypic resistance testing, were analyzed retrospectively. The outcome of the study was the lack of immune recovery after >3 years of follow-up, defined as a slope by linear regression <0. The viremia detectability ratio was defined as the number of HIV RNA values of >50 copies/ml divided by the number of HIV RNA measurements during follow-up. Logistic regression was used for univariable and multivariable analysis. Median (Q1, Q3) values at baseline were the following: age 40 (37, 45) years, years on antiretroviral therapy 4.45 (3.65, 5.47), HIV RNA 3.91 (3.39, 4.53) log(10) copies/ml, CD4+ T-cell 358 (211, 524)/µl. After 3.13 years of follow-up, 375 patients (45.4%) showed a lack of immune recovery. The risk of lack of immune recovery increased independently with increasing baseline CD4+ counts (OR=1.104 per 50-cell increase, 95% CI=1.069-1.142, P<0.0001), increasing viremia detectability ratio during follow-up (OR=1.145 per 0.1-unit increase, 95% CI=1.093-1.202, P<0.0001), and with earlier calendar years of resistance testing (overall effect: P=0.0007). In conclusion, no pol mutation is associated independently with the lack of immune recovery., (Copyright © 2011 Wiley-Liss, Inc.)

Background: There is not yet consensus on interpretation of genotypic HIV-1 resistance to darunavir (DRV). We validated existing rules and a newly derived score., Methods: Protease inhibitor (PI)-failing patients starting a DRV/ritonavir-based regimen, with available baseline resistance genotypes, were extracted from three Italian databases. Virological response (VR) was analysed between 4 and 32 follow-up weeks, defined as a drop from baseline HIV RNA of ≥2 log(10) or a value <50 copies/ml if the last measurement had been obtained at ≤12 weeks and as HIV RNA<50 copies/ml if it had been obtained at >12 weeks of follow-up. DRV/ritonavir resistance was interpreted by seven algorithms. A new weighted score (DRV-2009) was derived and validated, analysing associations of protease mutations with VR., Results: A total of 217 patients were analysed, with a mean (±sd) follow-up time of 17 (±9) weeks. At baseline, median HIV RNA was 4.26 log(10) copies/ml (IQR 3.11-5.03); VR was achieved in 135/217 (62%) patients. Adjusting for use of a new drug class, number of previous PIs experienced, CD4(+) T-cell count and HIV RNA, only the Rega DRV/ritonavir interpretation was significantly associated with VR (per increase in susceptibility category, OR 1.94, 95% CI 1.32-2.86; P<0.001). The DRV-2009 score V11I+L33F+R41K+I47V+2*I50V+2*I54M+K55R+D60E+L74P+L76V+N88D+2*L89V-L10I/V-I13V-G16E-G48V-F53I/L-I62V-I66F-V77I (<0 indicating susceptibility, 0-1 intermediate resistance and ≥2 resistance) correlated with VR in the derivation set (n=132, R=0.395; P<0.001). In the validation set (n=85), after adjusting for mutual interpretation and new use of enfuvirtide, DRV-2009 (P=0.017) and Rega (P=0.013) were both independently associated with VR., Conclusions: In contrast to the other algorithms, both the DRV-2009 score and Rega interpretation showed a robust predictive capacity of VR to DRV/ritonavir-containing regimens.

Background: To study the prevalence, predictors and outcome of late HIV diagnosis in the Icona cohort, according to the new European consensus definition of late diagnosis., Methods: In this observational cohort study we investigated patients diagnosed with HIV over 3 months preceding enrolment who were defined as diagnosed late if they presented with AIDS or a CD4(+) T-cell count ≤ 350/mm³ (European consensus definition). We estimated the prevalence of late diagnosis, identified factors associated with being diagnosed late and looked at the prognostic value of the European consensus definition of late presentation to predict subsequent clinical progression (new AIDS events or death)., Results: In total, 1,438/2,276 patients (63%) were defined as diagnosed late using the new European Consensus definition. Of these, 387 (16%) were AIDS-presenters. Predictors of being diagnosed late were older age, non-Italian origin, high HIV RNA and unemployment (versus retirement). A total of 293 patients showed clinical progression (3 events/100 person-years of follow-up, 95% CI: 2.7-3.4). Presenting late was strongly associated with a >5-fold increased risk of disease progression., Conclusions: In our observational setting with free access to care, more than 60% of new HIV diagnoses occurred below the recommended threshold for initiating antiretroviral treatment. Presenting late for care was associated with a high risk of clinical progression.

Understanding the determinants of virus transmission is a fundamental step for effective design of screening and intervention strategies to control viral epidemics. Phylogenetic analysis can be a valid approach for the identification of transmission chains, and very-large data sets can be analysed through parallel computation. Here we propose and validate a new methodology for the partition of large-scale phylogenies and the inference of transmission clusters. This approach, on the basis of a depth-first search algorithm, conjugates the evaluation of node reliability, tree topology and patristic distance analysis. The method has been applied to identify transmission clusters of a phylogeny of 11,541 human immunodeficiency virus-1 subtype B pol gene sequences from a large Italian cohort. Molecular transmission chains were characterized by means of different clinical/demographic factors, such as the interaction between male homosexuals and male heterosexuals. Our method takes an advantage of a flexible notion of transmission cluster and can become a general framework to analyse other epidemics., (© 2011 Macmillan Publishers Limited. All rights reserved.)

Protease inhibitor (PI)-resistant HIV-1 has hardly ever been detected at failed boosted PI-based first-line antiretroviral regimens in clinical trials. However, this phenomenon has not been investigated in clinical practice. To address this gap, data from patients starting a first-line lopinavir/ritonavir (LPV/rtv)-based therapy with available baseline HIV-1 RNA load, a viral genotype and follow-up viral load after 3 and 6 months of treatment were extracted from the Italian Antiretroviral Resistance Cohort Analysis (ARCA) observational database. Based on survival analysis, 39 (7.1%) and 43 (7.8%) of the 548 examined patient cases had an HIV-1 RNA >500 and >50 copies/ml, respectively, after 6 months of treatment. Cox proportional hazard models detected baseline HIV-1 RNA (RH 1.79, 95%CI 1.10-2.92 per 1-log(10) increase, P=0.02) and resistance to the nucleoside backbone (RH 1.04, 95%CI 1.02-1.06 per 10-point increase using the Stanford HIVdb algorithm, P<0.001) as independent predictors of HIV-1 RNA at >500 copies/ml, but not at the >50 copies/ml cutoff criteria. Higher baseline viral load, older patient age, heterosexual route of infection and use of tenofovir/emtricitabine were predictors of failure at month 3 using the 50-copy and/or 500-copy threshold. Resistance to LPV/rtv did not occur or increase in any of the available 36 follow-up HIV-1 genotypes. Resistance to the nucleoside backbone (M184V) developed in four cases. Despite the likely differences in patient population and adherence, both the low rate of virological failure and the lack of development of LPV/rtv resistance documented in clinical trials are thus confirmed in clinical practice.

Background: Trofile is the prospectively validated HIV-1 tropism assay. Its use is limited by high costs, long turn-around time, and inability to test patients with very low or undetectable viremia. We aimed at assessing the efficiency of population genotypic assays based on gp120 V3-loop sequencing for the determination of tropism in plasma viral RNA and in whole-blood viral DNA. Contemporary and follow-up plasma and whole-blood samples from patients undergoing tropism testing via the enhanced sensitivity Trofile (ESTA) were collected. Clinical and clonal geno2pheno[coreceptor] (G2P) models at 10% and at optimised 5.7% false positive rate cutoff were evaluated using viral DNA and RNA samples, compared against each other and ESTA, using Cohen's kappa, phylogenetic analysis, and area under the receiver operating characteristic (AUROC)., Results: Both clinical and clonal G2P (with different false positive rates) showed good performances in predicting the ESTA outcome (for V3 RNA-based clinical G2P at 10% false positive rate AUROC = 0.83, sensitivity = 90%, specificity = 75%). The rate of agreement between DNA- and RNA-based clinical G2P was fair (kappa = 0.74, p < 0.0001), and DNA-based clinical G2P accurately predicted the plasma ESTA (AUROC = 0.86). Significant differences in the viral populations were detected when comparing inter/intra patient diversity of viral DNA with RNA sequences., Conclusions: Plasma HIV RNA or whole-blood HIV DNA V3-loop sequencing interpreted with clinical G2P is cheap and can be a good surrogate for ESTA. Although there may be differences among viral RNA and DNA populations in the same host, DNA-based G2P may be used as an indication of viral tropism in patients with undetectable plasma viremia.

Objectives: To test retrospectively the ability of four freely available rules-based expert systems to predict short- and medium-term virological outcome following an antiretroviral treatment switch in pre-treated HIV-1 patients., Methods: The HIV-1 genotype interpretation systems (GISs) HIVdb, ANRS, Rega and AntiRetroScan were tested for their accuracy in predicting response to highly active antiretroviral therapy using 8 week (n = 765) and 24 week (n = 634) follow-up standardized treatment change episodes extracted from the Italian Antiretroviral Resistance Cohort Analysis (ARCA) database. A genotypic sensitivity score (GSS) was derived for each genotype-treatment pair for the different GISs and tested as a predictor of virological treatment outcome by univariable and multivariable logistic regression as well as by receiver operating characteristic curve analysis. The two systems implementing drug potency weights (AntiRetroScan and Rega) were evaluated with and without this correction factor., Results: All four GSSs were strong predictors of virological treatment outcome at both 8 and 24 weeks after adjusting for baseline viro-immunological parameters and previous drug exposure (odds ratios ranging from 2.04 to 2.43 per 1 unit GSS increase; P < 0.001 for all the systems). The accuracy of AntiRetroScan and Rega was significantly increased by drug potency weighting with respect to the unweighted versions (P

The virological and immunological outcomes in patients carrying multiclass-resistant HIV-1, their predictors, and their impact on disease progression were investigated. Antiretroviral-experienced patients carrying at least one primary resistance mutation (IAS-USA 2006) to two to three classes of antiretroviral drugs were analyzed for achieving an HIV-1 RNA <50 copies/ml, a CD4 count increase of >200 cells/microl from baseline, and progression to an AIDS-defining event or death. Survival analysis was performed using the Kaplan-Meier estimates and predictors of different outcomes were analyzed using Cox's regression models. A total of 236 patients were identified. Of these 73% reached HIV-1 RNA <50 copies/ml. Higher genotypic sensitivity score of the salvage regimen, lower viral load, and more recent calendar year at genotyping were independently associated with virological response. Immunological response (58%) was predicted by a more recent calendar year, the achievement of an undetectable viral load, and higher CD4 counts at genotyping. Thirty-three patients showed clinical progression: achieving HIV-1 RNA <50 copies/ml predicted AIDS-free survival, independently from other significant cofactors. In individuals with multiclass-resistant HIV-1, virological suppression and immunological recovery are becoming more easily accessible with more recent therapies. The achievement of virological suppression is a strong predictor of reduced clinical progression.

Background: HLA-B*5701 is strongly related to abacavir hypersensitivity reactions (HSRs). Polymorphisms at position 245 of HIV type-1 (HIV-1) reverse transcriptase (RT) show an association with HLA-B*5701 suggesting that viral genotyping performed for antiretroviral drug resistance testing could reduce human leukocyte antigen (HLA) screening necessity to prevent abacavir HSR., Methods: To further test the validity of 245 codon analysis results for predicting HSR, we analysed 1,179 sequences from 752 HIV-1-infected patients., Results: Mutant amino acid residues in RT 245 were found in 30.6% of sequences. Among 239 patients with multiple longitudinal genotypes, 245 residues varied in 37 (15.5%) from wild type to mutant and/or vice versa. All these changes appeared during antiretroviral treatment. A total of 15 out of 229 (6.5%) abacavir-treated patients developed a clinically confirmed HSR: all carried B subtypes. There was no significant difference in the prevalence of 245 mutants between abacavir-treated patients with HSR (27%) and those without (29%), even after limiting the analysis to subtype B carriers., Conclusions: The significant intraindividual variability of 245 residues and the lack of their association with clinically confirmed HSR argue against their use as viral genetic markers to exclude patients at risk for HSR.

Background: This study aimed to examine the evolution of genotypic drug resistance prevalence in treatment-failing patients in the multicentre, Italian, Antiretroviral Resistance Cohort Analysis (ARCA)., Methods: Patients with a drug resistance genotype test performed between 1999 and 2006 at failure of a combination antiretroviral therapy and with complete treatment history were selected. The prevalence of resistance was measured overall, per calendar year, per drug class and per treatment line at failure., Results: The overall resistance prevalence was 81%. Resistance to nucleoside reverse transcriptase inhibitors (NRTIs) declined after 2002 (68% in 2006; chi(2) for trend P=0.004); resistance to non-NRTIs (NNRTIs) stabilized after 2004; and resistance to protease inhibitors (PIs) declined after 2001 (43% in 2006; P=0.004). In first-line failures, NRTI resistance decreased after 2002 (P=0.006), NNRTI resistance decreased after 2003 (P=0.001) and PI resistance decreased after 2001 (P<0.001). Independent predictors of resistance to any class were HIV type-1 transmission by heterosexual contacts as compared with injecting drug use, a higher number of experienced regimens, prior history of suboptimal therapy, higher viral load and CD4+ T-cell counts, more recent calendar year and viral subtype B carriage, whereas the use of PI-based versus NNRTI-based regimens at failure was associated with a reduced risk of resistance. There was an increase of type-1 thymidine analogue and of protease mutations L33F, I47A/V, I50V and I54L/M, whereas L90M decreased over calendar years., Conclusions: During more recent years, emerging drug resistance has decreased, particularly in first-line failures. The prevalence continues to be high in multiregimen-failing patients.

Background: The extent to which HIV-1 replication capacity (RC) influences the response to therapy remains to be established., Methods: Phenotypic susceptibility and RC of baseline isolates (n = 139) from patients enrolled in the ARGENTA trial were measured and correlated to treatment outcomes over 36 months., Results: RC in baseline isolates correlated with the number of phenotypically active drugs (R = 0.34, P < 0.001). Crude viral RC did not predict treatment outcomes. When viral RC was adjusted by baseline CD4 cell counts, HIV-1 RNA levels, and phenotypic susceptibility to the rescue regimen, it showed significant association with the immunologic outcome (per log10 RC higher, mean difference in 36 months' time-averaged change from baseline CD4 count = -68 cells/microL; P = 0.020). In the subgroup of patients with 3 or more phenotypically active drugs in the salvage regimen (n = 35, median RC = 65%), subjects carrying isolates with RC < or =65% as compared to those with RC >65% had better time-averaged HIV-1 RNA responses (mean: -1.04 vs. -0.32 log10 copies/mL; P = 0.012) and CD4 cell responses (mean: 132 vs. -7 cells/microL; P = 0.006). Among patients with HIV-1 RNA levels persistently >500 copies/mL (n = 61), RC, on a log10 basis, was inversely associated with time-averaged 36-month CD4 cell responses (beta = -0.26; P = 0.046)., Conclusion: After normalizing for viral susceptibility to the employed regimen or in patient subsets with suboptimal virologic response, higher viral RC may predict worse subsequent treatment outcomes.

The aim of this study was to establish the prevalence and predictors of genotypic resistance of HIV-1 to lopinavir and fosamprenavir from patients failing protease inhibitors (PI)-based regimens. We selected 643 HIV-1-infected patients with available treatment history who underwent genotypic resistance assays for virological failure from a clinical site and from the Stanford database. According to the genotypic resistance interpretation of the Stanford algorithm, proportions of viruses showing full susceptibility to fosamprenavir and lopinavir were 32% and 34%, respectively (p =ns). Proportions of viruses fully susceptible to lopinavir/r and fosamprenavir/r according to the Agence Nationale pour la Recherche sur le SIDA (ANRS) algorithm, were 81% and 81%, respectively. According to the Rega algorithm, proportions of viruses showing full susceptibility to fosamprenavir/r and lopinavir were 80% and 70%, respectively (p<0.001). According to the ANRS and Rega interpretations, the time on therapy predicted susceptibility to lopinavir/r, while susceptibility to fosamprenavir/r according to ANRS was predicted by the number of prior PI regimens experienced. According to the Stanford interpretation, prior indinavir exposure predicted resistance to lopinavir/r and fosamprenavir/r while prior nelfinavir use predicted susceptibility to both drugs. After failing PI-based regimens, the majority of viruses retained a predicted susceptibility to fosamprenavir/r and lopinavir/r. In patients failing PIs, the interpretation of genotypic resistance to fosamprenavir may change considerably according to the different algorithms and in respect to the effect of pharmacokinetic boosting with ritonavir.

Objectives: A major barrier to successful viral suppression in HIV type 1 (HIV-1)-infected individuals is the emergence of virus resistant to antiretroviral drugs. We explored the evolution of genotypic drug resistance prevalence in treatment-failing patients from 1999 to 2005 in a clinical cohort., Patients and Methods: Prevalence of major International AIDS Society-USA HIV-1 drug resistance mutations was measured over calendar years in a population with treatment failure and undergoing resistance testing. Predictors of the presence of resistance mutations were analysed by logistic regression., Results: Significant reductions of the prevalence of resistance to all three drug classes examined were observed. This was accompanied by a reduction in the proportion of treatment-failing patients. Independent predictors of drug resistance were the earlier calendar year, prior use of suboptimal nucleoside analogue therapy, male sex and higher CD4 levels at testing., Conclusions: In a single clinical cohort, we observed a decrease in the prevalence of resistance to all three examined antiretroviral drug classes over time. If this finding is confirmed in multicentre cohorts it may translate into reduced transmission of drug-resistant virus from treated patients.

We investigated, in patients tested between 1991 and 2004, the patterns of mutually exclusive human immunodeficiency virus-1 thymidine-analogue mutations (TAMs) in 4039 reverse-transcriptase sequences with > or = 1 TAM. TAM pattern 1, which included M41L and L210W and excluded K70R and is coupled with more-extensive cross-resistance to drugs, became the most frequent pattern after 1996. In 1465 genotypes from 684 patients in whom highly active antiretroviral therapy (HAART) was unsuccessful, predictors of this pattern were the number of previous HAART regimens undergone (adjusted odds ratio [OR], 1.09 [95% confidence interval {CI}, 1.02-1.16]), use of stavudine/lamivudine (adjusted OR, 1.42 [95% CI, 1.05-1.99]), use of nevirapine (adjusted OR, 1.60 [95% CI, 1.14-2.24]), use of efavirenz (adjusted OR, 1.56 [95% CI, 1.08-2.27]), and use of ritonavir (adjusted OR, 1.35 [95% CI, 1.04-1.75]).

Background: Although efavirenz (EFV) and lopinavir/ ritonavir (LPV/r) are both recommended antiretroviral agents for combination therapy in drug-naive HIV-infected patients, no randomized comparison of their efficacy and tolerability is available yet. A multi-cohort prospective observational comparative study was performed., Methods: Efficacy was examined comparing time to virological failure, CD4 recovery and clinical progression. Tolerability was examined comparing time to treatment discontinuation for any reason and for toxicity and time to liver enzymes or lipid alterations. Survival analysis was conducted by an intent-to-treat principle using the Kaplan-Meier method, and standard and weighted Cox regression models., Results: A total of 674 antiretroviral-naive patients starting a two nucleoside reverse transcriptase inhibitor regimen plus either EFV (n = 481) or LPV/r (n = 193) were examined. At baseline, patients starting LPV/r had higher HIV RNA and lower CD4+ T-cell counts. There was no difference in the adjusted hazards of virological failure (LPV/r versus EFV relative hazard [RH] 1.16, 95% confidence intervals [CI]: 0.58-2.32, P = 0.67), CD4 recovery (RH = 0.93, 95% CI: 0.66-1.30, P = 0.66), clinical progression (RH = 1.64, 95% CI: 0.70-3.84, P = 0.25), drug discontinuation for toxicity (RH = 0.92, 95% CI: 0.51-1.64, P = 0.76) and for any reason, and rates of liver enzyme and total/low density lipoprotein (LDL) cholesterol elevation. In contrast, the rate of triglycerides elevations (> 1 NCEP Adult Treatment Panel III category increase) was higher in the LPV/r group (RH = 1.69, 95% CI: 1.14-2.50; P = 0.01). Models weighted for the inverse of conditional probability of receiving either drug applied to the efficacy endpoints yielded similar results. CD4 recovery with both drugs was also similar in the lowest CD4 strata., Conclusions: Our analysis suggests similar efficacy and tolerability for EFV- or LPV/r-based first-line antiretroviral regimens. LPV/r was associated with higher rates of hypertriglyceridaemia.

Objective: To investigate the influence of genotypic resistance-guided HIV-treatment decisions on long-term clinical and virological outcomes in patients failing antiretroviral therapy by a prospective 30-month observation following a 6-month randomized study (Argenta trial)., Methods: Patients (n=174) with virological failure on highly active antiretroviral therapy (HAART) were initially randomized (1:1) to receive empirical therapy or guidance by genotypic resistance results. After month 6, all patients with HIV RNA >1,000 copies/ml received genotypic resistance tests and expert advice. Predictors of virological and clinical outcomes were analysed by logistic regression and Cox's regression models., Results: There was a gradual increase in the proportion of patients with HIV RNA <400 copies/ml with 29.3% at 36 months (intent-to-treat) without differences between initial randomization arms. Independent predictors of 36-month virological response were the use of a salvage therapy with less daily doses and a more pronounced 3-month viral load drop. At 36 months, 84% survived without new AIDS events/death. Independent predictors of new AIDS events/death were previous AIDS events, higher baseline viral load, less pronounced 3-month viral load drop and, in a separate model, baseline protease substitutions K20M/R and 184V., Conclusions: The virological benefit of genotype-guided treatment decisions was continuously appreciable over time. Short-term virological response and viral cross-resistance were independent predictors of long-term outcomes.

Background: It is not well defined whether concentration-controlled intervention (CCI) and rules-based human immunodeficiency virus (HIV) type 1 genotype drug-resistance interpretation (GI) or virtual phenotype drug-resistance interpretation (VPI) may improve the outcome of HIV salvage therapy., Methods: In a prospective, randomized, controlled trial, patients were randomized (on a factorial basis) to change treatment after either GI or VPI, and they then were further randomized to the control arm (no CCI) or the CCI arm. Protease inhibitor (PI) and nonnucleoside reverse-transcriptase inhibitor (NNRTI) trough concentration (Ctrough) values were determined at weeks 1, 4, 12, and 24 of the study., Results: Among 230 patients, virological benefit (defined by an HIV RNA load of <400 copies/mL at week 24) was not statistically different, either between patients in the GI and VPI arms or between patients in the CCI and control arms. A virological benefit was found for patients in the CCI arm, compared with patients in the control arm, but this benefit was not statistically significant (56.8% vs. 64.3% at week 4 and 63.6% vs. 74% at week 12). Dosage adaptation was possible for only a fraction of patients, because of low rates of treatment adherence or patient refusal to increase dosages. In the logistic regression analysis, independent predictors of virological response at week 24 were a PI Ctrough value and/or an NNRTI Ctrough value in the higher quartiles (or above cutoff levels) and a low number of PIs previously received. Moreover, receipt of a regimen that contained PIs boosted with ritonavir was an independent predictor of virological response., Conclusions: The present study did not support the routine use of CCI for patients undergoing salvage treatment, probably as a result of existing difficulties associated with its clinical application. However, a higher Ctrough value appeared to be correlated with treatment response. No major differences were found between VPI or GI when they are used together with expert advice for the selection of salvage treatment combinations.

Background: Little is known about CD4 cell count changes in patients with high CD4 cell counts who interrupt antiretroviral therapy, especially in those with a nadir of 250-350 x 10 cells/l., Methods: Data derived from 139 patients from seven prospective cohorts who had > 12 months highly active antiretroviral therapy (HAART), CD4 cell count nadir of > 250 x 10 cells/l and at pre-interruption of > 500 x 10 cells/l. Endpoint was time to CD4 cell count < 350 x 10 cells/l or reinitiation of treatment., Results: At interruption, the median CD4 cell count was 800 x 10 cells/l, median viral load was 1.7 log10 copies/ml. At the time of analysis, 63 (45.3%) had resumed therapy or experienced < 350 x 10 cells/l CD4 cells over a median interruption of 75 weeks. Of these, 33 (52.4%) experienced a decline to < 350 x 10 cells/l and 30 (47.6%) restarted therapy before their CD4 cell count had fallen below this level. In 43 patients with CD4 cell nadir of 251-350 x 10 cells/l, median time to therapy resumption or CD4 cell count < 350 x 10 cells/l was 61 weeks. Higher CD4 cell count nadir, longer duration of viral load suppression on therapy, and higher viral load level at interruption were independently associated with longer time to restart therapy. The risk of clinical events was 5 per 1000 person-years of follow-up., Conclusions: Patients who started therapy with CD4 cell count of 250-350 x 10 cells/l and who later interrupted therapy appear able to remain off therapy with a CD4 cell count > 350 x 10 cells/l for a substantial period of time.

High level HIV-1 drug resistance in recently infected treatment-naive individuals correlates with sub-optimal virological responses to highly active antiretroviral therapy (HAART). To determine whether genotypic HIV-1 drug resistance in chronic naive patients, as interpreted by various systems, could predict the virological outcomes of HAART, isolates from patients enrolled in a prospective observational cohort (ICoNA) prior to treatment start were genotyped. Genotypic susceptibility scores (GSS) assigned to the initial HAART regimens using the interpretations of pre-therapy resistance mutations by 13 systems were related to virological outcomes. Of 415 patients, 42 (10%) had at least one major resistance mutation. According to the different interpretations, 1.9-20.5% of patients had some level of resistance to at least one drug in the initial regimen. In multivariable analysis, GSS from two systems significantly predicted the time to virological success: Rega 5.5, for each unit increase in GSS adjusted relative hazard (RH) 1.86 [95% confidence intervals (95% CI): 1.15-3.02] and hivresistanceWeb v3, RH 1.87 (95% CI: 1.00-3.48). With three other systems, GSS showed a trend towards a significant prediction of success: Retrogram 1.6, RH 2.33 (95% CI: 0.98-5.53), Menéndez 2002, RH 2.36 (95% CI: 0.97-5.72) and Stanford hivdb, RH 2.06 (95% CI: 0.94-4.49). Genotypic resistance testing coupled with adequate interpretation in chronic naive patients can usefully identify those at risk of sub-optimal virological response to HAART. This work was presented in part at the First European Workshop on HIV Drug Resistance. Luxembourg, 4-6 March 2003 (Abstract 44); and at the 9th European Conference on CIinical AIDS Therapy. Warsaw, 25-28 October 2003 (Abstract F6/7).

Objectives: To evaluate whether fuzzy operators can be usefully applied to the interpretation of genotypic HIV-1 drug resistance by experts, and to improve the prediction of salvage therapy outcome by adapting interpretation rules of genotypic resistance on the basis of their association with virological response data., Methods: We used a clinical dataset of 231 patients failing highly active antiretroviral therapy (HAART) and starting salvage therapy with baseline resistance genotyping and virological outcomes after 3 and 6 months. A set of rules predicting genotypic resistance was initially derived from an expert (ADL). Rules were implemented using a fuzzy logic approach and the virological outcomes dataset used for the training phase. The resulting algorithm was validated using a separate set of 184 selected patients by correlating the resulting predicted activity with observed virological response at 3 months. For comparison, the expert systems from the drug resistance group of the Agence Nationale de Recherches sur le SIDA (ANRS-AC11) and the algorithm from the Stanford's HIV drug resistance database (Stanford HIVdb) were evaluated on the same set., Results: The starting algorithm had a correlation with virological outcomes of R2=0.06 (P=0.0001). After the training phase the correlation with virological outcomes increased to R2=0.19 (P<0.000001). In the validation set of patients, the activity of the salvage regimen predicted by the fuzzy algorithm was the only variable independently predictive of the 3-month viral load change even after adjusting by the activity predicted by the two expert systems and baseline viral load (for each 10% salvage regimen's activity increase, mean HIV RNA change from baseline: -0.27 log10 copies/ml; 95% CI -0.39, -0.15)., Conclusion: Using fuzzy operators in a virological outcomes training database to implement a rules-based algorithm for genotypic resistance interpretation, significant improvements of outcomes prediction were obtained. The resulting algorithm showed an independent predictive capability of virological outcomes over that of two rules-based interpretation algorithms made by experts. Although the system was trained and validated on a limited number of cases, the approach deserves further evaluation.

To determine the variability of genotypic human immunodeficiency virus (HIV) type 1 drug-resistance interpretation by available expert systems and its clinical implications, 261 subjects for whom a potent antiretroviral regimen was failing who were starting salvage therapy were evaluated. The association of the genotypic susceptibility score (GSS) of the salvage regimen, according to 11 interpretation systems, with HIV RNA outcomes for 6 months was examined. GSS was highly variable, as determined by the different interpretation systems, and showed independent correlation with changes from baseline HIV RNA levels at 6 months with 5 systems--Stanford hivdb, GuideLines 3.0, Retrogram 1.4, HIVresistanceWeb, and São Paulo University. Most GSSs predicted virologic response in regimens containing stavudine, lamivudine, efavirenz, or indinavir. Selected systems predicted response in regimens containing didanosine, abacavir, or nelfinavir, and no system predicted outcome of boosted protease inhibitors. GSSs predicted changes in HIV RNA levels better in adherent patients than in nonadherent individuals. Interpretation may be improved, and knowledge should be used uniformly throughout different expert systems.

Genotypic assays are widely used tools for determining human immunodeficiency virus type 1 (HIV-1) drug resistance and for guiding treatment changes in patients failing antiretroviral therapy. Several systems have been developed to interpret the complex influence of key amino acid substitutions of the enzymes targeted by therapy on the phenotypic susceptibility or clinical response to available antiretroviral agents. This overview identifies 21 systems giving an interpretation on how amino acid substitutions affect phenotypic drug susceptibility or clinical activity of anti-HIV-1 agents. There was substantial variability in the mechanisms underlying the interpretations, the nature of the systems, their intended use, the source type of their knowledge base, and their update and output. Most of the systems could be accessed for free on the internet, functioned as rule-based algorithms updated by experts and at least partially based on literature evidence, and offered an automated report through a software. Nevertheless, the rule base was not always clarified. An update of the rules and the clinical validation of the systems are presented to help in the critical evaluation of their possible use. Importantly, only 8 systems were intended for clinical use and 5 of these had at least partially undergone clinical validation.