Temporal trend of drug-resistance and APOBEC editing in PBMC genotypic resistance tests from HIV-1 infected virologically suppressed individuals.

BACKGROUND: We aimed at evaluating the temporal trend of drug-resistance and APOBEC editing from HIV-DNA genotypic resistance tests (GRT) in virologically suppressed individuals. MATERIAL AND METHODS: Major resistance mutations (MRM), genotypic susceptibility score (GSS) for the current regimen and APOBEC-related mutations (APO-M) were evaluated. Potential changes in trends of MRM and APO-M over-time were assessed and predictors of MRM detection or sub-optimal GSS (GSS<2) at HIV-DNA-GRT were estimated through logistic regression analyses. RESULTS: Among the 1126 individuals included, 396 (35.2%) harboured at least one MRM (23.4% to NRTI, 18.8% to NNRTI, 7.7% to PI and 1.4% to INSTI [N=724]); 132 (12.3%) individuals showed a GSS <2. APO-M and stop codons were found in 229 (20.3%) and 105 (9.3%) individuals, respectively. APO-DRMs were found in 16.8% of individuals and were more likely observed in those individuals with stop codons (40.0%) compared to those without (14.4%, P<0.001). From 2010 to 2021 no significant changes of resistance or APO-M were found. Positive predictors of MRM detection at HIV-DNA GRT were drug abuse, subtype B infection, and a prolonged and complex treatment history. Perinatal infection and having at least 2 stop codons were associated with a current suboptimal regimen. CONCLUSIONS: In virologically suppressed individuals, resistance in HIV-DNA and the extent of APOBEC editing were generally stable in the last decade. A careful evaluation of APOBEC editing might be helpful to improve the reliability of HIV-DNA GRT. Further investigations are required to understand how to apply the estimation of APOBEC editing in refining genotypic evaluation.

Analysing the efficacy and tolerability of dolutegravir plus either rilpivirine or lamivudine in a multicentre cohort of virologically suppressed PLWHIV.

OBJECTIVES: We aimed to investigate and compare the efficacy and safety of two dolutegravir-based two-drug regimens: dolutegravir + lamivudine versus dolutegravir + rilpivirine. METHODS: We analysed a cohort of people living with HIV (PLWHIV) switching to dolutegravir + lamivudine or dolutegravir + rilpivirine. We excluded from the analysis PLWHIV with no available pre-switch genotypic test or with a known resistance mutation to one of the study drugs. We evaluated incidence of virological failure (VF) and treatment discontinuation (TD), as well as changes in immunological and metabolic parameters. RESULTS: We enrolled 592 PLWHIV: 306 in the lamivudine group and 286 in the rilpivirine group. We observed nine VFs in the lamivudine group [1.4 VF per 100 patient-years of follow-up (PYFU)] and four VFs in the rilpivirine group (0.6 VF per 100 PYFU). Subsequent genotypic analysis showed no acquired resistance-associated mutations in those experiencing VF. Estimated probability of maintaining virological suppression at 144 and 240 weeks were 96.6% and 92.7%, respectively, in the lamivudine group and 98.7% and 98.7%, respectively, in the rilpivirine group (log-rank P = 0.172). The estimated probability of maintaining study regimen at Week 240 was 82.3% in the lamivudine group and 85.9% in the rilpivirine group (log-rank P = 0.018). We observed a significant improvement in CD4+ cell count at Week 240 in the lamivudine group (P = 0.012); in the rilpivirine group we registered a significant increase in CD4/CD8 ratio (P = 0.014). CONCLUSIONS: Both analysed strategies are effective and safe as switch strategies in clinical practice, with a low incidence of VF and a favourable immunological recovery, even in the long term.

Virological outcomes with dolutegravir plus either lamivudine or two NRTIs as switch strategies: a multi-cohort study.

OBJECTIVES: To compare the efficacy of dolutegravir plus lamivudine dual therapy (DT) with that of dolutegravir plus two NRTIs triple therapy (TT) as switch strategies. METHODS: A multicentre cohort of HIV-positive, HBsAg-negative patients with viral suppression (HIV-RNA ≤50 copies/mL) switching to DT or TT was retrospectively selected from the ARCA database. The effect of DT versus TT on virological failure (VF; defined as two consecutive HIV-RNA values >50 copies/mL or one HIV-RNA value ≥200 copies/mL) was evaluated by multivariable Cox regression models, overall and after stratifying for the presence of NRTI resistance-associated mutations (RAMs). RESULTS: From December 2014 to June 2020, 628 patients were eligible: 118 (18.8%) started tenofovir/emtricitabine/dolutegravir, 306 (48.7%) abacavir/lamivudine/dolutegravir and 204 (32.5%) lamivudine/dolutegravir. The DT group had significantly higher nadir and baseline CD4 counts, a higher duration of viral suppression and a lower prevalence of RAMs at historical genotype. Overall, 41 VF occurred after a median of 1.7 years of follow-up, with a lower, but not statistically significant, rate for DT [versus TT, adjusted HR (aHR) = 0.58, 95% CI = 0.25-1.34]. However, DT was associated with less VF in the absence of RAMs when compared with tenofovir-based TT (aHR = 0.20, 95% CI = 0.06-0.67), but not with abacavir-based TT (aHR = 0.43, 95% CI = 0.17-1.11). Conversely, in the setting of pre-existing M184V/I, DT showed a trend to increased risk of VF (versus tenofovir-based TT, aHR = 137.50, 95% CI = 4.24-4464.06; versus abacavir-based TT, aHR = 33.88, 95% CI = 1.75-656.47). CONCLUSIONS: Lamivudine/dolutegravir maintenance DT showed similar efficacy to dolutegravir-based TT; however, past M184V/I may favour VF.

Transmitted drug resistance to NRTIs and risk of virological failure in naïve patients treated with integrase inhibitors.

OBJECTIVES: Nucleoside reverse transcriptase inhibitor (NRTI) transmitted drug resistance mutations (TDRMs) could increase the risk of virological failure (VF) of first-line integrase strand transfer inhibitor (InSTI)-based regimens. METHODS: Patients starting two NRTIs (lamivudine/emtricitabine plus abacavir/tenofovir) plus raltegravir or dolutegravir were selected from the EuResist cohort. The role of NRTI genotypic susceptibility score and of specific TDRMs in VF (i.e. two consecutive viral loads > 50 HIV-1 RNA copies/mL or a single viral load ≥ 200 copies/mL after 3 months from antiretroviral therapy start) was evaluated in the overall population and according to the InSTI employed. RESULTS: From 2008 to 2017, 1095 patients were eligible for the analysis (55.5% men, median age 39 years). In all, 207 VFs occurred over 1023 patient-years of follow-up. The genotypic susceptibility score (GSS) had no effect on the risk of VF in the overall population. However, the presence of M184V/I independently predicted VF of raltegravir- but not dolutegravir-based therapy when compared with a fully-active backbone [adjusted hazard ratio (aHR) = 3.09, P = 0.035], particularly when associated with other non-thymidine analogue mutations (aHR = 27.62, P = 0.004). Higher-zenith HIV-RNA and lower nadir CD4 counts independently predicted VF. CONCLUSIONS: NRTI backbone TDRMs increased the risk of VF with raltegravir-based but not dolutegravir-based regimens.

Treatment outcomes of integrase inhibitors, boosted protease inhibitors and nonnucleoside reverse transcriptase inhibitors in antiretroviral-naïve persons starting treatment.

OBJECTIVES: Although outcomes of antiretroviral therapy (ART) have been evaluated in randomized controlled trials, experiences from subpopulations defined by age, CD4 count or viral load (VL) in heterogeneous real-world settings are limited. METHODS: The study design was an international multicohort collaboration. Logistic regression was used to compare virological and immunological outcomes at 12 ± 3 months after starting ART with an integrase strand transfer inhibitor (INSTI), contemporary nonnucleoside reverse transcriptase inhibitor (NNRTI) or boosted protease inhibitor (PI/b) with two nucleos(t)ides after 1 January 2012. The composite treatment outcome (cTO) defined success as VL < 200 HIV-1 RNA copies/mL with no regimen change and no AIDS/death events. Immunological success was defined as a CD4 count > 750 cells/µL or a 33% increase where the baseline CD4 count was ≥ 500 cells/µL. Poisson regression compared clinical failures (AIDS/death ≥ 14 days after starting ART). Interactions between ART class and age, CD4 count, and VL were determined for each endpoint. RESULTS: Of 5198 ART-naïve persons in the International Cohort Consortium of Infectious Diseases (RESPOND), 45.4% started INSTIs, 26.0% PI/b and 28.7% NNRTIs; 880 (17.4%) were aged > 50 years, 2539 (49.4%) had CD4 counts < 350 cells/µL and 1891 (36.8%) had VL > 100 000 copies/mL. Differences in virological and immunological success and clinical failure among ART classes were similar across age groups (≤ 40, 40-50 and > 50 years), CD4 count categories (≤ 350 vs. > 350 cells/µL) and VL categories at ART initiation (≤ 100 000 vs. > 100 000 copies/mL), with all investigated interactions being nonsignificant (P > 0.05). CONCLUSIONS: Differences among ART classes in virological, immunological and clinical outcomes in ART-naïve participants were consistent irrespective of age, immune suppression or VL at ART initiation. While confounding by indication cannot be excluded, this provides reassuring evidence that such subpopulations will equally benefit from contemporary ART.

HIV MDR is still a relevant issue despite its dramatic drop over the years.

OBJECTIVES: To evaluate the prevalence and therapeutic relevance of drug resistance among isolates from ART-experienced HIV-1-infected patients over the past two decades in Italy. METHODS: Dynamics of resistance to one, two and three or more antiretroviral classes were evaluated from 1999-2018. Virological success (VS) after the latest therapy switch was evaluated according to cumulative class resistance and cumulative genotypic susceptibility score (Stanford HIV_DB algorithm). RESULTS: Among 13 663 isolates (from 6739 patients), resistance to at least one drug class decreased sharply from 1999 to 2010 (≤2001, 84.6%; 2010, 43.6%; P < 0.001), then remained relatively constant at ∼40% during 2010-18, with the proportion of resistance to three or more classes also stable (∼5%). After 2008, integrase inhibitor resistance slightly increased from 5.6% to 9.7% in 2018 and contributed to resistance, particularly in isolates with resistance to three or more classes (one class, 8.4%; two classes, 15.3%; three or more classes, 34.7%, P < 0.001). Among 1827 failing patients with an available follow-up, by 1 year after genotype-guided therapy start the probability of VS was 87.6%. Patients with cumulative resistance to three or more classes and receiving a poorly active regimen showed the lowest probability (62.6%) of VS (P < 0.001) compared with all other patients (≥81.8%). By Cox regression analysis, cumulative MDR and receiving poorly active antiretroviral regimens were associated with a lower hazard of VS compared with those without resistance. CONCLUSIONS: A dramatic drop of HIV-1 drug resistance at failure has been achieved over the last two decades in Italy; resistance to three or more classes is low but present among currently failing patients. Its management still requires a rational and careful diagnostic and therapeutic approach.

Optimization strategies for HIV, hepatitis and syphilis testing in Infectious Disease Clinic and Dermatology Unit of Modena: 7-year results of collaboration experience.

BACKGROUND: Screening tests for human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis infections performed in at-risk population show a higher number of positive tests compared to those carried out in the general population. 'Test & Counselling' Ambulatory of Infectious Disease Clinic (T&C-IDC) and Sexually Transmitted Diseases Ambulatory of Dermatology Unit (STDs-DU) of Modena began collaboration in 2010 and adopted a common diagnostic serological profile since 2013. OBJECTIVES: The main objective was to analyse the number of screening tests performed in the T&C-IDC and STDs-DU, comparing the results obtained after the adoption of the shared protocol with the previous period. The secondary aim was to evaluate the linkage to care of newly diagnosed patients. METHODS: Consecutive patients referred to the T&C-IDC and STDs-DU from January 2010 to December 2016, with at least one performed screening test for HIV, HBV, HCV and syphilis were enrolled. Referral of patients with a new infection was obtained by capture-recapture methods in hospital databases. RESULTS: During the 7-year observation, we collected 13 117 admittances for 9154 patients. A significant increase in the number of screening tests (P < 0.001) and ratio between tests and admissions (P = 0.002) was observed. A total of 644 (7.0%) people with at least one infection were diagnosed. Among these, the most common was syphilis (41.9%), followed by HBV (25.7%), HCV (21.4%) and HIV (10.9%). Syphilis occurred predominantly in Italians (72.5%) and males (75.7%), as like as HCV, while foreign-born (85.5%) mainly harboured HBV infection. HIV diagnosis was detected more frequently among males (67.1%) with a similar proportion between Italians and foreign-born. Five hundred and forty-three out of 644 (84.3%) patients were linked to care. CONCLUSION: The collaboration between T&C-IDC and STDs-DU has proven to work well increasing the diagnosis over the time and obtaining good results in linkage to care.

Dolutegravir (DTG)-containing regimens after receiving raltegravir (RAL) or elvitegravir (EVG): Durability and virological response in a large Italian HIV drug resistance network (ARCA).

BACKGROUND: Dolutegravir (DTG) is a next-generation HIV integrase inhibitor (INI) with an increased genetic barrier to resistance with respect to raltegravir (RAL) or elvitegravir (EVG). Few data are available on the durability of DTG-containing regimens. OBJECTIVES: We aimed at investigating the duration of the DTG-containing regimen, the occurrence of an HIV-1 RNA blip, and factors associated with DTG virological response. STUDY DESIGN: From the Antiviral Response Cohort Analysis database, we selected 89 HIV-1-positive four-class-experienced subjects who started DTG after receiving RAL or EVG. Factors associated with durability and virological response were analysed by logistic regression. RESULTS: After a median duration of 18.8 [0.4-76.2] months, 79/89 (88.8%) subjects were still on DTG. All subjects remaining on DTG at the end of follow-up had undetectable HIV-1 RNA, compared to 5/10 subjects who discontinued DTG. DTG discontinuation was less frequent in patients who had experienced ≥10 regimens (HR 0.11, p = 0.040). The probability of having an HIV-1 RNA positive value at the last follow-up significantly increased in patients with non-B HIV-1 subtype (HR 5.77, p < .001) and significantly decreased in patients with CD4 nadir >200/µL (HR 0.29, p = 0.038), with more than 10 previous regimens (HR 0.27, p = 0.040), and who harbored virus with IN mutations (HR 0.12, p = 0.023) at DTG start. CONCLUSIONS: After previous exposure to first-generation INIs, treatment with DTG showed long durability and did not show virological rebound after virological suppression. Subjects infected with a non-B HIV-1 subtype had a greater risk of having detectable HIV-1 RNA at the last observation.

Impact of transmitted HIV-1 drug resistance on the efficacy of first-line antiretroviral therapy with two nucleos(t)ide reverse transcriptase inhibitors plus an integrase inhibitor or a protease inhibitor.

Objectives: To examine the impact of transmitted drug resistance (TDR) on response to first-line regimens with integrase strand transfer inhibitors (INSTIs) or boosted protease inhibitors (bPIs). Methods: From an Italian observational database (ARCA) we selected HIV-1-infected drug-naive patients starting two NRTIs and either an INSTI or a bPI, with an available pre-ART resistance genotype. The endpoint was virological failure (VF; plasma HIV-1 RNA >200 copies/mL after week 24). WHO surveillance drug resistance mutations and the Stanford algorithm were used to classify patients into three resistance categories: no TDR (A), TDR but fully-active ART prescribed (B), TDR and at least low-level resistance to one or more prescribed drug (C). Results: We included 1365 patients with a median follow-up of 96 weeks (IQR 54-110): 1205 (88.3%) starting bPI and 160 (11.7%) INSTI. Prevalence of TDR was 6.1%, 12.5%, 2.6% and 0% for NRTI, NNRTI, bPI and INSTI, respectively. Cumulative Kaplan-Meier estimates for VF at 48 weeks were 11% (95% CI 10.1%-11.9%) for the bPI group and 7.7% (95% CI 5.4%-10%) for the INSTI group. In the INSTI group, cumulative estimates for VF at 48 weeks were 6% (95% CI 4%-8%) in resistance category A, 5% (95% CI 1%-10%) in B and 50% (95% CI 30%-70%) in C (P < 0.001). Resistance category C [versus A, adjusted hazard ratio (aHR) 12.6, 95% CI 3.2-49.8, P < 0.001] and nadir CD4 (+100 cells/mm3, aHR 0.6, 95% CI 0.4-0.9, P = 0.03) predicted VF. In the bPI group, VF rates were not influenced by baseline resistance. Conclusions: Our data support the need for NRTI resistance genotyping in patients starting an INSTI-based first-line ART.

Evolution of transmitted HIV-1 drug resistance and viral subtypes circulation in Italy from 2006 to 2016.

OBJECTIVES: The aim was to evaluate the evolution of transmitted HIV-1 drug resistance (TDR) prevalence in antiretroviral therapy (ART)-naïve patients from 2006 to 2016. METHODS: HIV-1 sequences were retrieved from the Antiviral Response Cohort Analysis (ARCA) database and TDR was defined as detection of at least one mutation from the World Health Organization (WHO) surveillance list. RESULTS: We included protease/reverse transcriptase sequences from 3573 patients; 455 had also integrase sequences. Overall, 68.1% of the patients were Italian, the median CD4 count was 348 cells/µL [interquartile range (IQR) 169-521 cells/µL], and the median viral load was 4.7 log10 HIV-1 RNA copies/mL (IQR 4.1-5.3 log10 copies/mL). TDR was detected in 10.3% of patients: 6% carried mutations to nucleos(t)ide reverse transcriptase inhibitors (NRTIs), 4.4% to nonnucleos(t)ide reverse transcriptase inhibitors (NNRTIs), 2.3% to protease inhibitors (PIs), 0.2% to integrase strand transfer inhibitors (INSTIs) and 2.1% to at least two drug classes. TDR declined from 14.5% in 2006 to 7.3% in 2016 (P = 0.003): TDR to NRTIs from 9.9 to 2.9% (P = 0.003) and TDR to NNRTIs from 5.1 to 3.7% (P = 0.028); PI TDR remained stable. The proportion carrying subtype B virus declined from 76.5 to 50% (P < 0.001). The prevalence of TDR was higher in subtype B vs. non-B (12.6 vs. 4.9%, respectively; P < 0.001) and declined significantly in subtype B (from 17.1 to 8.8%; P = 0.04) but not in non-B subtypes (from 6.1 to 5.8%; P = 0.44). Adjusting for country of origin, predictors of TDR were subtype B [adjusted odds ratio (AOR) for subtype B vs. non-B 2.91; 95% confidence interval (CI) 1.93-4.39; P < 0.001], lower viral load (per log10 higher: AOR 0.86; 95% CI 0.75-0.99; P = 0.03), site in northern Italy (AOR for southern Italy/island vs. northern Italy, 0.61; 95% CI 0.40-0.91; P = 0.01), and earlier calendar year (per 1 year more recent: AOR 0.95; 95% CI 0.91-0.99; P = 0.02). CONCLUSIONS: The prevalence of HIV-1 TDR has declined during the last 10 years in Italy.

Dynamics and phylogenetic relationships of HIV-1 transmitted drug resistance according to subtype in Italy over the years 2000-14.

Background: Transmitted drug-resistance (TDR) remains a critical aspect for the management of HIV-1-infected individuals. Thus, studying the dynamics of TDR is crucial to optimize HIV care. Methods: In total, 4323 HIV-1 protease/reverse-transcriptase sequences from drug-naive individuals diagnosed in north and central Italy between 2000 and 2014 were analysed. TDR was evaluated over time. Maximum-likelihood and Bayesian phylogenetic trees with bootstrap and Bayesian-probability supports defined transmission clusters. Results: Most individuals were males (80.2%) and Italian (72.1%), with a median (IQR) age of 37 (30-45) years. MSM accounted for 42.2% of cases, followed by heterosexuals (36.4%). Non-B subtype infections accounted for 30.8% of the overall population and increased over time (<2005-14: 19.5%-38.5%, P < 0.0001), particularly among Italians (<2005-14: 6.5%-28.8%, P < 0.0001). TDR prevalence was 8.8% and increased over time in non-B subtypes (<2005-14: 2%-7.1%, P = 0.018). Overall, 467 transmission clusters (involving 1207 individuals; 27.9%) were identified. The prevalence of individuals grouping in transmission clusters increased over time in both B (<2005-14: 12.9%-33.5%, P = 0.001) and non-B subtypes (<2005-14: 18.4%-41.9%, P = 0.006). TDR transmission clusters were 13.3% within the overall cluster observed and dramatically increased in recent years (<2005-14: 14.3%-35.5%, P = 0.005). This recent increase was mainly due to non-B subtype-infected individuals, who were also more frequently involved in large transmission clusters than those infected with a B subtype [median number of individuals in transmission clusters: 7 (IQR 6-19) versus 4 (3-4), P = 0.047]. Conclusions: The epidemiology of HIV transmission changed greatly over time; the increasing number of transmission clusters (sometimes with drug resistance) shows that detection and proper treatment of the multi-transmitters is a major target for controlling HIV spread.

Virological response and resistance profile in HIV-1-infected patients starting darunavir-containing regimens.

OBJECTIVES: We evaluated the virological response in patients starting a regimen based on darunavir/ritonavir (DRV/r), which is currently the most widely used ritonavir-boosted protease inhibitor. METHODS: Data from 206 drug-naïve and 327 PI-experienced patients starting DRV/r 600/100 mg twice daily (DRV600) or 800/100 mg once daily (DRV800) were examined. The probabilities of virological success (VS) and virological rebound (VR) were evaluated in survival analyses. Baseline DRV/r resistance and its evolution at failure were also examined. RESULTS: DRV600 was preferentially administered in patients with complex requirements (older age, higher viraemia, lower CD4 cell count and DRV/PI resistance) compared with DRV800. By 12 months, the probability of achieving VS was 93.2% and 84.3% in drug-naïve and PI-experienced patients, respectively. The higher the baseline viraemia, the longer was the time required to achieve VS, both in drug-naïve patients [>500 000 HIV-1 RNA copies/mL: median [interquartile range (IQR)] 6.1 (5.1-10.3) months; 100 000-500 000 copies/mL: median (IQR) 4.9 (3.8-6.1) months; <100 000 copies/mL: median (IQR) 3.9 (3.5-4.8) months; P < 0.001] and in PI-experienced patients [≥100 000 copies/mL: median (IQR) 7.2 (5.7-11.6) months; <100 000 copies/mL: median (IQR) 2.8 (2.4-3.3) months; P < 0.001]. In PI-experienced patients, the probability of VR was higher for higher viraemia levels (22.3% for ≥100 000 copies/ml vs. 9.7% for <100 000 copies/mL; P = 0.007). Baseline resistance did not affect the virological response. At failure, a high percentage of patients maintained virus susceptible to all PIs (drug-naïve: 95%; PI-experienced: 80%). Despite being used more often in patients with more complex requirements, DRV600 performed as well as DRV800. CONCLUSIONS: In clinical practice, use of DRV/r (with its flexible dosage) results in high rates of virological response. These data support the use of PI/r in patients whose characteristics require potent drugs with a high genetic barrier.

Absence of liver steatosis in HIV-HCV co-infected patients receiving regimens containing tenofovir or abacavir.

BACKGROUND: In human immunodeficiency virus-hepatitis C virus (HIV-HCV) co-infected patients, steatosis has been independently associated with a number of antiretroviral drugs, including stavudine, especially in patients with non-3 HCV genotypes. We retrospectively investigated the presence of steatosis among HIV-HCV co-infected and HCV mono-infected patients, and the role of tenofovir disoproxil fumarate (TDF) or abacavir (ABC) in determining hepatic steatosis. METHODS: Liver steatosis was retrospectively evaluated in all consecutive biopsies performed in the period 2000-2008 in HCV mono-infected and HIV-HCV co-infected patients. A steatosis rate of >5 % was considered to be significant, and a multivariate logistic analysis was performed to evaluate factors associated with steatosis. RESULTS: In total, 393 HCV-infected patients underwent liver biopsy during the study period, of whom 205 (52.2 %) were co-infected with HIV. A steatosis rate of >5 % was diagnosed in 33.0 % of HCV mono-infected and in 47.8 % of HIV-HCV co-infected patients (P = 0.003). The rate of steatosis was higher in patients resuming antiretroviral therapy (54.7 %) than in naïve patients (33.3 %; P = 0.006). When the overall population was considered, steatosis was associated to HCV genotype 3 [odds ratio (OR) 4.53, 95 % confidence interval (CI) 2.71-7.58; P < 0.001]. In terms of the use of nucleos(t)ide drugs in HIV co-infected patients, multivariate analysis showed that only in patients with HCV genotypes other than genotype 3 was steatosis related to the use of stavudine (OR 5.38, 95 % CI 1.18-24.53; P = 0.03). The use of TDF (OR 1.07, 95 % CI 0.39-2.88; P = 0.898) or ABC (OR 0.592, 95 % CI 0.09-4.07; P = 0.594) was not associated with steatosis. CONCLUSION: In HCV mono-infected and HIV-HCV co-infected patients, steatosis appears to be a virus-mediated effect of HCV genotype 3. In HIV patients infected with HCV genotypes other than genotype 3, the risk of developing steatosis was higher in those patients resuming antiretroviral regimens containing old drugs rather than the new antiretrovirals.

Prevalence of HIV-1 integrase mutations related to resistance to dolutegravir in raltegravir naïve and pretreated patients.

The prevalence of HIV-1 integrase mutations related to resistance to the next-generation integrase inhibitor (INI), dolutegravir (DTG), was assessed in 440 INI-naïve subjects and in 120 patients failing a raltegravir (RTG)-containing regimen. Of the mutations selected by DTG in vitro, S153FY was not detected in any isolate while L101I and T124A were highly prevalent in both groups and significantly associated with non-B subtype. RTG-selected double and triple mutants, mostly the G140S/Q148H variant, were detected in only 32 (26.7%) RTG-treated patients. As L101I and T124A do not appear to exert any major effect in vivo and double and triple mutants resistant to DTG are infrequently selected by RTG, DTG can be effectively used in INI-naïve patients and may retain activity in many patients failing RTG.

A dual acting compound with latanoprost amide and nitric oxide releasing properties, shows ocular hypotensive effects in rabbits and dogs.

The IOP lowering effects of NCX 139, a new chemical entity comprising latanoprost amide and a NO-donating moiety, were compared to those of the respective des-nitro analog in in vitro assays and in rabbit and dog models of ocular hypertension. The NO donor, molsidomine as well as the prostamide bimatoprost (Lumigan(®)) and the prostaglandin agonist, latanoprost (Xalatan(®)) were also investigated for comparison. NCX 139 but not its des-nitro analog resulted in NO-mediated vascular relaxant effect in pre-contracted rabbit aortic rings (EC(50)=0.70±0.06 µM; E(max)=80.6±2.9%). Like bimatoprost (IC(50)=3.07±1.3 µM) or latanoprost (IC(50)=0.48±0.15 µM), NCX 139 displaced (3)H-PGF2α binding on recombinant human prostaglandin-F (FP) receptors with an estimated potency of 0.77±0.13 µM. In transient ocular hypertensive rabbits, bimatoprost and latanoprost were not effective while molsidomine elicited a dose-dependent reduction of IOP confirming the responsiveness of rabbits to NO but not to FP receptor agonists. NCX 139 tested at a therapeutically relevant dose, significantly lowered IOP while the des-nitro analog was not effective (0.03% NCX 139, Δ(max)=-12.8±2.0 mmHg). In glaucomatous dogs, 0.03% NCX 139 decreased IOP to a greater extent compared to an equimolar dose of the respective des-nitro derivative (Δ(max)=-4.6±1.0 and -2.7±1.3 mmHg, respectively for NCX 139 and its des-nitro analog). Albeit with low potency, NCX 139 also resulted effective in normotensive dogs while it did not reduce IOP in normotensive rabbits. NCX 139, a compound targeting two different and important mechanisms, is endowed with ocular hypotensive effects more evident in hypertensive conditions which may be of interest in the search of more effective treatments for hypertensive glaucoma.

Evaluation of the Abbott Real-Time HIV-1 quantitative assay with dried blood spot specimens.

The Abbott Real-Time HIV-1 assay was evaluated for its performance in quantification of human immunodeficiency virus type 1 (HIV-1) RNA in dried blood spot (DBS) samples. In total, 169 blood samples with detectable plasma HIV-1 RNA were used to extract RNA from paired DBS and liquid plasma samples, using the automated Abbott m Sample Preparation System (m2000sp). HIV-1 RNA was then quantitated by the m2000rt RealTime analyser. RNA samples suitable for real-time PCR were obtained from all but one (99.4%) of the DBS samples and HIV-1 RNA was detected in 163/168 (97.0%) samples. The correlation between HIV-1 RNA values measured in paired DBS and plasma samples was very high (r = 0.882), with 78.5% and 99.4% of cases differing by <0.5 and 1.0 log, respectively. Retesting of DBS replicates following 6 months of storage at 2-8 degrees C showed no loss of HIV-1 RNA in a subset of 89 samples. The feasibility of DBS testing coupled with automated sample processing, and the use of a latest-generation FDA-approved real-time PCR-based system, represents an encouraging first step for viral load measurement in reference centres in developing countries where access to antiretroviral therapy is expanding.