Viral clearance after early corticosteroid treatment in patients with moderate or severe covid-19.

The aim of this study was to evaluate the impact of early treatment with corticosteroids on SARS-CoV-2 clearance in hospitalized COVID-19 patients. Retrospective analysis on patients admitted to the San Raffaele Hospital (Milan, Italy) with moderate/severe COVID-19 and availability of at least two nasopharyngeal swabs. The primary outcome was the time to nasopharyngeal swab negativization. A multivariable Cox model was fitted to determine factors associated with nasopharyngeal swab negativization. Of 280 patients included, 59 (21.1%) patients were treated with steroids. Differences observed between steroid users and non-users included the proportion of patients with a baseline PaO2/FiO2 ≤ 200 mmHg (45.8% vs 34.4% in steroids and non-steroids users, respectively; p = 0.023) or ≤ 100 mmHg (16.9% vs 12.7%; p = 0.027), and length of hospitalization (20 vs 14 days; p < 0.001). Time to negativization of nasopharyngeal swabs was similar in steroid and non-steroid users (p = 0.985). According to multivariate analysis, SARS-CoV-2 clearance was associated with age ≤ 70 years, a shorter duration of symptoms at admission, a baseline PaO2/FiO2 > 200 mmHg, and a lymphocyte count at admission > 1.0 × 109/L. SARS-CoV-2 clearance was not associated with corticosteroid use. Our study shows that delayed SARS-CoV-2 clearance in moderate/severe COVID-19 is associated with older age and a more severe disease, but not with an early use of corticosteroids.

The potential role of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) single-tablet regimen in the expanding spectrum of fixed-dose combination therapy for HIV.

Single-tablet regimens (STRs) of highly safe and effective combination antiretroviral therapy (cART) have had a significant beneficial impact on the clinical outcomes and lives of people living with HIV (PLHIV). As a consequence, healthcare professionals caring for PLHIV in high-income countries have increasingly focused on issues beyond those related to HIV itself, i.e. HIV-related neurological disease, or associated opportunistic infections, which include co-infections, and primarily age- and lifestyle-related comorbidities such as cardiovascular disease, diabetes mellitus, renal impairment, osteoporosis and frailty. This review considers drug side effects and comorbidities seen in PLHIV and evaluates the role of a recently licensed STR - bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) - in mitigating some of those challenges. Factors that need to be evaluated for initial cART regimens include: pretreatment CD4 cell count; plasma HIV RNA; HIV drug resistance; hepatitis B co-infection; HLA-B*5701 status; drug-drug interactions; pregnancy and pregnancy potential; psychiatric and physical comorbidities such as renal or bone disease, as well as simplicity and adherence-friendliness, all of which need to be considered in all lines of therapy. BIC/FTC/TAF constitutes a new STR that includes an unboosted integrase strand transfer inhibitor with a high barrier against resistance with TAF and FTC. Its virological efficacy was non-inferior to dolutegravir-based regimens previously recommended by most guidelines for treatment initiation in large double-blind, randomised clinical trials in treatment-naïve or switch patients over 96 weeks. Tolerability and pharmacological properties of the regimen make it a useful tool to address several of the clinical management issues raised above.

The Management of Geriatric and Frail HIV Patients. A 2017 Update from the Italian Guidelines for the Use of Antiretroviral Agents and the Diagnostic Clinical Management of HIV-1 Infected Persons.

OBJECTIVE: This article deals with the attempt to join HIV and geriatric care management in the 2017 edition of the Italian guidelines for the use of antiretrovirals and the diagnostic-clinical management of HIV-1 infected persons. METHODS: The outlined recommendations are based on evidence from randomized clinical trials and observational studies published in peer-reviewed journals and/or presented at international scientific conferences in recent years. The principles of starting antiretroviral therapy in elderly patients and the viro-immunological goals are the same as in the general HIV population. However, there are some specificities to consider, related to the host as well as the therapy itself. HIV care in elderly patients must shift from a combined AntiRetroviral Therapy specific approach to a more comprehensive management, and from a disease-based model (list of co-morbidities) to a multi-morbidity and frailty standpoint. The implementation of a geriatric approach, based on the Comprehensive Geriatric Assessment, is essential and consists of a broader evaluation of health status. This multidimensional and multidisciplinary evaluation is focused on the development of a tailored intervention plan. Polypharmacy is a frequent condition in the older population and an independent risk factor for negative health-related outcomes. This can be overcome with a multidisciplinary and cooperative approach involving HIV specialists, geriatricians and primary care physicians. CONCLUSION: The inclusion of geriatric care becomes necessary due to the novel needs of an evolving patient population. It is important to underline that the HIV specialist will continue to lead multidimensional interventions and optimize quality of care for HIV-positive people.

In vivo evidence that the cannabinoid receptor 2-63 RR variant is associated with the acquisition and/or expansion of HIV infection.

OBJECTIVES: The aim of the study was to investigate whether the rs35761398 variants of the cannabinoid receptor 2 (CB2) gene may influence the acquisition of HIV infection and the clinical presentation of HIV/hepatitis C virus (HCV) coinfection. METHODS: We compared 166 HIV/HCV-coinfected patients with 186 HCV-monoinfected patients, all with biopsy-proven chronic hepatitis (using the Ishak scoring system), naïve for anti-HCV treatment and tested for the CB2 rs35761398 polymorphism (using the TaqMan assay). RESULTS: The HIV/HCV-coinfected patients were more frequently male (P < 0.002), were younger (P < 0.001), and had lower median BMI (P < 0.001) and HCV RNA (P < 0.05) and higher median aspartate aminotransferase (AST; P < 0.001), alanine aminotransferase (ALT; P < 0.001) and gamma glutamyl transferase (GGT; P < 0.001) levels than the HCV-monoinfected patients. The CB2 RR variant predominated in HIV/HCV-coinfected patients (45.8% vs. 31.2% in HCV-monoinfected patients; P < 0.001) and the CB2 QR variant in HCV-monoinfected patients (57.5% vs. 38.6% in HIV/HCV-coinfected patients; P < 0.00001), and the CB2 QQ variant was equally distributed. Focusing on patients with the CB2 QQ variant, the 26 HIV/HCV-coinfected patients, compared with the 21 HCV-monoinfected patients, showed less severe liver necroinflammation [lower histological activity index (HAI)] (P < 0.05). Of the patients with the CB2 RR variant, the 76 HIV/HCV-coinfected patients, compared with the 58 HCV-monoinfected patients, were more frequently male (P < 0.05), were younger (P < 0.001), and had a lower median body mass index (BMI; P < 0.001), a higher median AST level (P < 0.001), a higher mean HAI score (P < 0.05) and a higher rate of cases with severe steatosis (P = 0.05). In an analysis of variance (anova) of HCV/HIV-coinfected and HCV-monoinfected patient data, those with the CB2 RR variant (P = 0.003) and of male sex (P = 0.002) were more prevalent in the HCV/HIV-coinfected group. CONCLUSIONS: There is the suggestion of a positive effect of the CB2 RR variant on HIV acquisition and/or spread, which is in accordance with previous in vitro observations.

Efficacy and safety of boosted darunavir-based antiretroviral therapy in HIV-1-positive patients: results from a meta-analysis of clinical trials.

Darunavir/ritonavir (DRV/r) is a second-generation protease inhibitor used in treatment-naïve and -experienced HIV-positive adult patients. To evaluate efficacy and safety in these patient settings, we performed a meta-analysis of randomized controlled trials. We considered eight studies involving 4240 antiretroviral treatment (ART)-naïve patients and 14 studies involving 2684 ART-experienced patients. Regarding efficacy in the ART-naive patients, the virological response rate was not significantly different between DRV/r and the comparator. For the ART-experienced failing patients, the virological response rate was significantly higher with DRV/r than with the comparator (RR 1.45, 95% CI: 1.01-2.08); conversely, no significant differences were found between the treatment-experienced and virologically controlled DRV/r and comparator groups. Regarding safety, the discontinuation rates due to adverse events (AEs) and DRV/r-related serious adverse events (SAEs) did not significantly differ from the rates in the comparator group (RR 0.84, 95% CI: 0.59-1.19 and RR 0.78, 95% CI: 0.57-1.05, respectively). Our meta-analysis indicated that DRV/r-based regimens were effective and tolerable for both types of patients, which was consistent with published data.

Long-term effectiveness of recommended boosted protease inhibitor-based antiretroviral therapy in Europe.

OBJECTIVES: The aim of the study was to evaluate the long-term response to antiretroviral treatment (ART) based on atazanavir/ritonavir (ATZ/r)-, darunavir/ritonavir (DRV/r)-, and lopinavir/ritonavir (LPV/r)-containing regimens. METHODS: Data were analysed for 5678 EuroSIDA-enrolled patients starting a DRV/r-, ATZ/r- or LPV/r-containing regimen between 1 January 2000 and 30 June 2013. Separate analyses were performed for the following subgroups of patients: (1) ART-naïve subjects (8%) at ritonavir-boosted protease inhibitor (PI/r) initiation; (2) ART-experienced individuals (44%) initiating the new PI/r with a viral load (VL) ≤500 HIV-1 RNA copies/mL; and (3) ART-experienced patients (48%) initiating the new PI/r with a VL >500 copies/mL. Virological failure (VF) was defined as two consecutive VL measurements >200 copies/mL ≥24 weeks after PI/r initiation. Kaplan-Meier and multivariable Cox models were used to compare risks of failure by PI/r-based regimen. The main analysis was performed with intention-to-treat (ITT) ignoring treatment switches. RESULTS: The time to VF favoured DRV/r over ATZ/r, and both were superior to LPV/r (log-rank test; P < 0.02) in all analyses. Nevertheless, the risk of VF in ART-naïve patients was similar regardless of the PI/r initiated after controlling for potential confounders. The risk of VF in both treatment-experienced groups was lower for DRV/r than for ATZ/r, which, in turn, was lower than for LPV/r-based ART. CONCLUSIONS: Although confounding by indication and calendar year cannot be completely ruled out, in ART-experienced subjects the long-term effectiveness of DRV/r-containing regimens appears to be greater than that of ATZ/r and LPV/r.

Soluble endothelial protein C receptor (sEPCR) as an inflammatory biomarker in naive HIV-infected patients during ART.

BACKGROUND: After the advent of ART, non-AIDS-related comorbidities are the main causes of death in HIV patients. Multiple biomarkers have been studied as markers of disease. We wanted to test soluble endothelial protein C receptor (sEPCR) in an HIV setting. OBJECTIVES: The primary objective was to determine whether sEPCR decreases after 48 weeks of ART in naive HIV patients. Secondary objectives were to compare sEPCR levels between patients with chronic HIV infection (CHI) and primary HIV infection (PHI) and to analyse if there is a correlation between sEPCR and both immunovirological parameters and different markers of inflammation. PATIENTS AND METHODS: We analysed sEPCR in 33 patients with CHI and 19 patients with PHI naive to ART. sEPCR was compared together with immunovirological parameters (HIV RNA and CD4 cell count) and IL-6 or D-dimer (DD). RESULTS AND CONCLUSIONS: After 48 weeks of ART, in CHI, the sEPCR decrease was significant (P = 0.0006) and sEPCR at baseline was correlated with both CD4 cell increase (r = +0.463, P = 0.007) and HIV RNA decrease (r = -0.363, P = 0.038). In PHI, sEPCR was stable (P = 0.35); there was a correlation between 48 week DD change and IL-6 change (r = +0.696, P = 0.0009) and also between 48 week DD change and sEPCR change (r = +0.553, P = 0.014). Despite the small sample size, we hypothesize that sEPCR levels reflect coagulant pathway activation caused by the endothelial damage during chronic infection more than a marker of the cytokine storm that occurs during PHI. Alternatively, in PHI, the link found between sEPCR and DD secondary to IL-6 suggests sEPCR is an indirect marker of inflammation.

Impact of PNPLA3 variants on liver histology of 168 patients with HIV infection and chronic hepatitis C.

This study analysed the impact of PNPLA3 variants on liver histology of 168 HIV/hepatitis C virus (HCV)-coinfected patients who were naïve for HCV treatment. A athologist unaware of the patients' condition graded liver fibrosis and necroinflammation (Ishak) and steatosis (Kleiner). Patients were tested for PNPLA3 variants and genotyped for the PNPLA3 rs738409 C to G variant underlying the I148M substitution. All were hepatitis B surface antigen negative and stated no alcohol abuse. The mean age was 40.6 (37.6-44.1) years, 72.6% were males, 42% had HCV genotype 3, 38.9% HCV genotype 1 and 79.2% were receiving highly active antiretroviral therapy. The 79 patients with the PNPLA3 p.148I/M or M/M variants more frequently showed severe steatosis (score 3-4) than the 89 with PNPLA3 p.148I/I (43% vs. 24.7%, p 0.001), whereas no difference was observed in the degree of necroinflammation or fibrosis. Compared with 112 patients with lower scores, 56 with severe steatosis showed higher body mass index (p 0.03), higher rate of HCV genotype 3 (55.6% vs. 35.2%, p 0.01), PNPLA3 p.148I/M or M/M (60.7% vs. 39.3%, p 0.01) and lower CD4(+) cells/mm(3) (514.00 (390.5-673.0) vs. 500.00 (399.0-627.0); p 0.002). At multivariate analysis, body mass index (p 0.01), HCV genotype 3 (p 0.006), CD4(+) cell count (p 0.005) and PNPLA3 p.148I/M or M/M variants (p 0.01) were found to be independent predictors of severe liver steatosis. The PNPLA3 p.148 I/M or M/M variants and CD4(+) cell count were the only independent predictors of severe steatosis in patients with HCV non-3 genotypes. This is the first study to show that among HIV/HCV-coinfected patients the PNPLA3 p.148I/M or M/M variant have substantially less impact on steatosis for those with HCV genotype 3 than non-genotype 3.

Distribution of natural resistance to NS3 protease inhibitors in hepatitis C genotype 1a separated into clades 1 and 2 and in genotype 1b of HIV-infected patients.

Naturally occurring resistance-associated variants (RAVs) within the protease domain of hepatitis C virus (HCV) genotype (G) 1a separated into clades 1 and 2, and G1b were investigated in 59 HIV/HCV coinfected patients. RAVs were detected in 10/23 G1a/clade 1 and 1/19 G1b (p 0.0059). A similar frequency of RAVs was found when comparing G1a/clade 2 and G1b (p 0.1672). A cross-resistance to the macrocyclic compounds simeprevir and paritaprevir was detected in two G1a/clade 2 and 1 G1b sequences and none of G1a/clade 1 sequences. The simultaneous characterization of subtype and natural RAVs by population analysis of the NS3 domain by may add important information for anti-HCV treatment strategies including protease inhibitors.

Dynamics of adaptive and innate immunity in patients treated during primary human immunodeficiency virus infection: results from Maraviroc in HIV Acute Infection (MAIN) randomized clinical trial.

We evaluated the dynamics of innate and adaptive immunity in patients treated with combined antiretroviral therapy (cART) during primary human immunodeficiency virus infection (PHI), enrolled in a prospective randomized trial (MAIN, EUDRACT 2008-007004-29). After 48 weeks of cART, we documented a reduction in activated B cells and CD8(+) T cells. Natural killer cell and dendritic cell frequencies were measured and a decrease in CD16(+) CD56(dim) with a reciprocal rise in CD56(high) natural killer cells and an increase in myeloid and plasmacytoid dendritic cells were recorded. In conclusion, 48 weeks of cART during PHI showed significant benefits for both innate and adaptive immunity.

Maraviroc 150 mg daily plus lopinavir/ritonavir, a nucleoside/nucleotide reverse transcriptase inhibitor-sparing regimen for HIV-infected naive patients: 48-week final results of VEMAN study.

Non-conventional strategies with nucleoside/nucleotide reverse transcriptase inhibitor-sparing regimens in antiretroviral naive human immunodeficiency virus (HIV) -infected patients have been explored in clinical trials. A prospective, open-label, randomized (1:1), multicentre, proof-of-concept trial (VEMAN study, EUDRACT number 2008-006287-11) was conducted assigning HIV-infected naive patients to once-daily maraviroc plus lopinavir/ritonavir (MVC group) or to tenofovir/emtricitabine plus lopinavir/ritonavir (TDF/FTC group). Clinical and laboratory data were collected at baseline, and after 4, 12, 24, 36 and 48 weeks with the objective to evaluate the 48-week virological and immunological efficacy. HIV-1 DNA load and CD4(+) T-cell subsets were analysed on frozen peripheral blood mononuclear cells collected at baseline, 4 and 48 weeks to explore the trend in HIV reservoirs. Fifty patients were randomized and included in the analysis. During follow up, HIV-1 RNA decreased similarly in both groups and, at week 48, all patients in the MVC group and 22/24 (96%) in the TDF/FTC group had < 50 copies/ml of HIV-1 RNA. CD4(+) trend during follow up was higher in maraviroc-treated patients (MVC group: 286 (183-343) versus TDF/FTC group: 199 (125-285); Mann-Whitney U-test: p 0.033). A significant 48-week increase of CCR5(+) CD4(+) T cells and CD4(+) effector memory cells was observed among maraviroc-treated patients (Wilcoxon signed rank test: p 0.016 and p 0.007, respectively). No significant variations were found in naive and central memory CD4(+) T cells. Among naive patients with an R5 virus, treatment with maraviroc and lopinavir/ritonavir was shown to provide a virological response compared to a triple therapy and a greater immunological benefit.

HIV DNA loads, plasma residual viraemia and risk of virological rebound in heavily treated, virologically suppressed HIV-infected patients.

In this single-centre, retrospective study, we analyzed data of 194 patients receiving antiretroviral therapy with <50 human immunodeficiency virus (HIV) RNA copies/mL in plasma and 318 HIV RNA/DNA paired samples. By kinetic polymerase chain reaction (kPCR) molecular system analysis, 104 (54%) subjects had undetectable HIV RNA and 90 (46%) had residual viraemia. Median (interquartile range) HIV DNA load was 780 (380-1930) copies/10(6) peripheral blood lymphocytes (PBL), and HIV DNA loads were independently associated with residual viraemia (p 0.002). Virological rebound occurred in 29/194 (15%) patients over a median (interquartile range) follow-up of 17.5 (13.5-31.5) months. Residual viraemia (p 0.002), but not HIV DNA load, was independently associated with virological rebound.

Virological rebound in human immunodeficiency virus-infected patients with or without residual viraemia: results from an extended follow-up.

Human immunodeficiency virus (HIV) -infected patients with HIV RNA loads of < 50 copies/mL were followed-up for a median (interquartile range) of 30.8 (11.7-32.9) months to study the effect of residual viraemia (RV) on virological rebound (VR). At baseline, 446 (60.3%) patients had undetectable HIV RNA (group A) and 293 (39.7%) had RV (1-49 HIV RNA copies/mL, group B) by kinetic PCR. VR occurred in 4 (0.9%) patients in group A and in 12 (4.1%) patients in group B (p 0.007). Time to VR was shorter among patients of group B (Log-rank test: p 0.003). However, the proportion of VR was extremely low also among patients with RV.

Factors influencing liver fibrosis and necroinflammation in HIV/HCV coinfection and HCV monoinfection.

OBJECTIVES: To define differences in liver histology between HIV/HCV coinfection and HCV monoinfection, and to investigate possible causative factors. METHODS: Liver biopsies (LBs) from 440 consecutive HIV/HCV-coinfected patients (Group HIV/HCV) and 374 consecutive HCV-monoinfected patients (Group HCV) were evaluated for necroinflammation and fibrosis (Ishak) by a pathologist unaware of the clinical and laboratory data. All patients were HBsAg-negative, with no history of alcohol abuse and naïve to anti-HCV treatment. At LB, 78.4% of patients in Group HIV/HCV were on an antiretroviral regimen. RESULTS: HIV/HCV-coinfected patients compared to the HCV-monoinfected patients were younger (p < 0.0001), more frequently males (p < 0.0001), and had HCV genotype 3 (p < 0.0001); they showed a good immunological condition (CD4+ cell count: 518 ± 166 cells/mm(3)). Patients in Group HIV/HCV more frequently showed a fibrosis score ≥4 (27.5 vs. 20.6%, p < 0.05) and a necroinflammation score ≥9 (25.9 vs. 13.4%; p < 0.0001). The prevalence of patients with fibrosis score ≥4 was significantly higher in older age classes in both Group HIV/HCV (p < 0.005) and Group HCV (p < 0.05). A necroinflammation score ≥9 was significantly higher in older age classes only in Group HIV/HCV (p < 0.05). A multivariate analysis for Group HIV/HCV revealed that the patient age and nadir of CD4+ cell count were independently associated to higher degrees of fibrosis, the patient age and antiretroviral treatment were associated to higher degrees of necroinflammation, and HCV genotype 3 was associated to higher degrees of steatosis. CONCLUSION: The data suggest a need for early anti-HCV treatment in both HCV-monoinfected and HIV/HCV-coinfected patients.

Stability of hepatitis C virus (HCV) RNA levels among interferon-naïve HIV/HCV-coinfected individuals treated with combination antiretroviral therapy.

OBJECTIVES: Infection with hepatitis C virus (HCV) is a major cause of chronic liver disease. High HCV RNA levels have been associated with poor treatment response. This study aimed to examine the natural history of HCV RNA in chronically HCV/HIV-coinfected individuals. METHODS: Mixed models were used to analyse the natural history of HCV RNA changes over time in HIV-positive patients with chronic HCV infection. RESULTS: A total of 1541 individuals, predominantly White (91%), male (73%), from southern (35%) and western central Europe (23%) and with HCV genotype 1 (58%), were included in the analysis. The median follow-up time was 5.0 years [interquartile range (IQR) 2.8 to 8.3 years]. Among patients not on combination antiretroviral therapy (cART), HCV RNA levels increased by a mean 27.6% per year [95% confidence interval (CI) 6.1-53.5%; P = 0.0098]. Among patients receiving cART, HCV RNA levels were stable, increasing by a mean 2.6% per year (95% CI -1.1 to 6.5%; P = 0.17). Baseline HCV RNA levels were 25.5% higher (95% CI 8.8 to 39.1%; P = 0.0044) in individuals with HCV genotype 1 compared with HCV genotypes 2, 3 and 4. A 1 log HIV-1 RNA copies/mL increase in HIV RNA was associated with a 10.9% increase (95% CI 2.3 to 20.2%; P = 0.012) in HCV RNA. CONCLUSIONS: While HCV RNA levels increased significantly in patients prior to receiving cART, among those treated with cART HCV RNA levels remained stable over time.

Number of daily pills, dosing schedule, self-reported adherence and health status in 2010: a large cross-sectional study of HIV-infected patients on antiretroviral therapy.

OBJECTIVES: The aim of the study was to assess whether pill burden is associated with self-reported adherence to current combination antiretroviral regimens and health status in a large sample of unselected and chronically treated HIV-infected patients. METHODS: An adherence and health status questionnaire was offered to all patients collecting their drugs between March and May 2010 at our clinic; both parameters were primarily evaluated using a visual analogue scale. Linear correlations were evaluated using Spearman's correlation coefficient. Wilcoxon's rank-sum test and the χ(2) test were used to compare quantitative and qualitative variables. The generalized linear model was used in multivariable analyses. RESULTS: Among 2763 subjects on treatment during the study period, 2114 (78.8% male; mean age 46.9 ± 8.84 years) were tested for adherence; 1803 (85.3%) had viral loads < 50 HIV-1 RNA copies/mL. After adjusting for age, gender, HIV risk factor, current CD4 count, pill burden and dosing interval, adherence was higher in patients with undetectable HIV RNA (P < 0.0001) and directly associated with current CD4 count (P = 0.029). After adjusting for the same variables, health status was better in patients with undetectable viraemia (P = 0.004) and in men who have sex with men (MSM) and heterosexuals compared with injecting drug users and those with other risk factors (P < 0.0001 for MSM and P = 0.008 for heterosexuals); it was also directly associated with current CD4 count (P < 0.0001) and inversely associated with age (P < 0.0001) and pill burden (P = 0.019). CONCLUSIONS: In this highly adherent population, the number of daily pills was related to self-reported health status but not to self-reported adherence, whereas the dosing interval did not influence self-reported adherence or health status.

Efficacy, adherence and tolerability of once daily tenofovir DF-containing antiretroviral therapy in former injecting drug users with HIV-1 receiving opiate treatment: results of a 48-week open-label study.

OBJECTIVE: To assess efficacy, adherence and tolerability of once daily antiretroviral therapy containing tenofovir disoproxil fumarate (DF) 300 mg in HIV-1-infected former injecting drug users receiving opiate treatment (IVDU). METHODS: European, 48-week, open-label, single-arm, multicenter study. Patients were either antiretroviral therapy-naive, restarting therapy after treatment discontinuation without prior virological failure or switching from existing stable treatment. RESULTS: Sixty-seven patients were enrolled in the study and 41 patients completed treatment. In the primary analysis (intent-to-treat missing=failure) at week 48, 34% of patients (23/67; 95% CI: 23%-47%) had plasma HIV-1 RNA <50 copies/mL. Using an intent-to-treat missing=excluded approach, the week 48 proportion of patients with plasma HIV-1 RNA <50 copies/mL increased to 56% (23/41; 95% CI: 40%-72%). Mean (standard deviation) increase from baseline in CD4+ cell count at week 48 was 176 (242) cells/mm(3). Although self-reported adherence appeared high, there were high levels of missing data and adherence results should be treated with caution. No new safety issues were identified. CONCLUSIONS: Levels of missing data were high in this difficult-to-treat population, but potent antiretroviral suppression was achieved in a substantial proportion of HIV-infected IVDU-patients.