Type I interferon response and vascular alteration in chilblain-like lesions during the COVID-19 outbreak.

BACKGROUND: The outbreak of chilblain-like lesions (CLL) during the COVID-19 pandemic has been reported extensively, potentially related to SARS-CoV-2 infection, yet its underlying pathophysiology is unclear. OBJECTIVES: To study skin and blood endothelial and immune system activation in CLL in comparison with healthy controls and seasonal chilblains (SC), defined as cold-induced sporadic chilblains occurring during 2015 and 2019 with exclusion of chilblain lupus. METHODS: This observational study was conducted during 9-16 April 2020 at Saint-Louis Hospital, Paris, France. All patients referred with CLL seen during this period of the COVID-19 pandemic were included in this study. We excluded patients with a history of chilblains or chilblain lupus. Fifty patients were included. RESULTS: Histological patterns were similar and transcriptomic signatures overlapped in both the CLL and SC groups, with type I interferon polarization and a cytotoxic-natural killer gene signature. CLL were characterized by higher IgA tissue deposition and more significant transcriptomic activation of complement and angiogenesis factors compared with SC. We observed in CLL a systemic immune response associated with IgA antineutrophil cytoplasmic antibodies in 73% of patients, and elevated type I interferon blood signature in comparison with healthy controls. Finally, using blood biomarkers related to endothelial dysfunction and activation, and to angiogenesis or endothelial progenitor cell mobilization, we confirmed endothelial dysfunction in CLL. CONCLUSIONS: Our findings support an activation loop in the skin in CLL associated with endothelial alteration and immune infiltration of cytotoxic and type I IFN-polarized cells leading to clinical manifestations.

Phylogenetic investigation of HCV-4d epidemic in Paris MSM HIV population reveals a still active outbreak and a strong link to the Netherlands.

OBJECTIVES: The hepatitis C virus (HCV) epidemic is evolving quickly despite new treatments, and due to behaviour changes increasing at-risk situations. We investigated potential origins and evolution of the HCV-4d French emergence among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM), in Paris in 2003. METHODS: We analysed all HCV sequences from the initial Paris outbreak with all newly available sequences publicly available, including sampling date and geographical location, resulting in 184, 68, 156, 107, 13 and 2 sequences from France, The Netherlands, other European countries, Africa, the Middle East or Turkey, Americas and Asia, respectively. Phylogenetic reconstruction was performed using maximum likelihood and Bayesian approaches. RESULTS: HCV-4d sequences from Europe were strongly separated from non-European sequences. Sequences from the initial Paris outbreak were all included into two well-separated and supported clusters with branch support at 100%, mean genetic distance <2.8 substitutions/100 nucleotides and >3.4 substitutions/100 nucleotides between their common ancestor and the previous node. The largest cluster interleaved French (n = 98) and Dutch (n = 28) sequences, suggesting several translocations between these countries. This cluster included 41 French sequences from Lyon sampled after 2014, highlighting its continuous spread within France since the initial outbreak. The smallest cluster included one Paris sequence with UK sequences (n = 9). DISCUSSION: A few previous works have shown HCV-4d transmissions occurring between a few countries. In our work, we suggest a new and large connection between France and The Netherlands MSM communities and highlight a well-separated pan-European transmission network. Large collaborative networks are needed to investigate ongoing transmissions across countries and help specific prevention measures.

Low incidence of acute rejection within 6 months of kidney transplantation in HIV-infected recipients treated with raltegravir: the Agence Nationale de Recherche sur le Sida et les Hépatites Virales (ANRS) 153 TREVE trial.

OBJECTIVES: High rates of clinical acute rejection after kidney transplantation have been reported in people living with HIV (PLHIV), probably as a consequence of drug interactions. We therefore investigated the incidence of acute rejection within 6 months of transplantation in HIV-infected recipients treated with a protease-inhibitor-free raltegravir-based regimen. METHODS: The Agence Nationale de Recherche sur le Sida et les Hépatites Virales (ANRS) 153 TREVE (NCT01453192) study was a prospective multicentre single-arm trial in adult PLHIV awaiting kidney transplantation, with viral load < 50 HIV-1 RNA copies/mL, CD4 T-cell count > 200 cells/µL, and HIV-1 strains sensitive to raltegravir, aiming to demonstrate 6-month clinical acute rejection rates < 30%. Time to transplantation was compared with that for uninfected subjects matched for age, sex and registration date. RESULTS: In total, 61 participants were enrolled in the study, and 26 underwent kidney transplantation. Two participants experienced clinical acute rejection, corresponding to an estimated clinical acute rejection rate of 8% [95% confidence interval (CI) 2-24%] at 6 and 12 months post-transplantation. HIV infection remained under control in all but one participant, who temporarily stopped antiretroviral treatment. Median time to transplantation was longer in PLHIV than in controls (4.3 versus 2.8 years, respectively; P = 0.002) and was not influenced by blood group. CONCLUSIONS: Acute rejection rates were low after kidney transplantation in PLHIV treated with a raltegravir-based regimen. However, PLHIV have poorer access to transplantation than HIV-uninfected individuals after registration on the waiting list.

HIV-1 drug resistance testing at second-line regimen failure in Arua, Uganda: avoiding unnecessary switch to an empiric third-line.

OBJECTIVES: The number of patients on second-line antiretroviral therapy is growing, but data on HIV drug resistance patterns at failure in resource-constrained settings are scarce. We aimed to describe drug resistance and investigate the factors associated with extensive resistance to nucleoside/nucleotide reverse transcriptase inhibitors (NRTI), in patients failing second-line therapy in the HIV outpatient clinic at Arua Regional Referral Hospital, Uganda. METHODS: We included patients who failed on second-line therapy (two consecutive viral loads ≥1000 copies/mm3 by SAMBA-1 point-of-care test) and who had a drug resistance test performed between September 2014 and March 2017. Logistic regression was used to investigate factors associated with NRTI genotypic sensitivity score (GSS) ≤1. RESULTS: Seventy-eight patients were included: 42% female, median age 31 years and median time of 29 months on second-line therapy. Among 70 cases with drug resistance test results, predominant subtypes were A (47%) and D (40%); 18.5% had ≥1 major protease inhibitor mutation; 82.8% had ≥1 NRTI mutation and 38.5% had extensive NRTI resistance (NRTI GSS ≤1). A nadir CD4 count ≤100/ml was associated with NRTI GSS ≤1 (OR 4.2, 95% CI [1.3-15.1]). Thirty (42.8%) patients were switched to third-line therapy, composed of integrase inhibitor and protease inhibitor (60% darunavir/r) +/- NRTI. A follow-up viral load was available for 19 third-line patients at 12 months: 84.2% were undetectable. CONCLUSIONS: Our study highlights the need for access to drug resistance tests to avoid unnecessary switches to third-line therapy, but also for access to third-line drugs, in particular integrase inhibitors. Low nadir CD4 count might be an indicator of third-line drug requirement for patients failing second-line therapy.

Emerging resistance mutations in PI-naive patients failing an atazanavir-based regimen (ANRS multicentre observational study).

Background: Atazanavir is a PI widely used as a third agent in combination ART. We aimed to determine the prevalence and the patterns of resistance in PI-naive patients failing on an atazanavir-based regimen. Methods: We analysed patients failing on an atazanavir-containing regimen used as a first line of PI therapy. We compared the sequences of reverse transcriptase and protease before the introduction of atazanavir and at failure [two consecutive viral loads (VLs) >50 copies/mL]. Resistance was defined according to the 2014 Agence Nationale de Recherche sur le SIDA et les Hépatites Virales (ANRS) algorithm. Results: Among the 113 patients, atazanavir was used in the first regimen in 71 (62.8%) patients and in the first line of a PI-based regimen in 42 (37.2%). Atazanavir was boosted with ritonavir in 95 (84.1%) patients and combined with tenofovir/emtricitabine or lamivudine (n = 81) and abacavir/lamivudine or emtricitabine (n = 22). At failure, median VL was 3.05 log10 copies/mL and the median CD4+ T cell count was 436 cells/mm3. The median time on atazanavir was 21.2 months. At failure, viruses were considered resistant to atazanavir in four patients (3.5%) with the selection of the following major atazanavir-associated mutations: I50L (n = 1), I84V (n = 2) and N88S (n = 1). Other emergent PI mutations were L10V, G16E, K20I/R, L33F, M36I/L, M46I/L, G48V, F53L, I54L, D60E, I62V, A71T/V, V82I/T, L90M and I93L/M. Emergent NRTI substitutions were detected in 21 patients: M41L (n = 2), D67N (n = 3), K70R (n = 1), L74I/V (n = 3), M184V/I (n = 16), L210W (n = 1), T215Y/F (n = 3) and K219Q/E (n = 2). Conclusions: Resistance to atazanavir is rare in patients failing the first line of an atazanavir-based regimen according to the ANRS. Emergent NRTI resistance-associated mutations were reported in 18% of patients.

Precore G1896A mutation is associated with reduced rates of HBsAg seroclearance in treated HIV hepatitis B virus co-infected patients from Western Africa.

The nucleotide substitution G1896A on the precore (pc) region has been implicated in virological and serological responses during treatment in hepatitis B virus (HBV)-infected patients. Whether this mutation affects the therapeutic course of HIV-HBV co-infected patients, especially from Western Africa, is unknown. In this prospective cohort study, 86 antiretroviral (ARV)-naïve HIV-HBV co-infected patients from Côte d'Ivoire, initiating ARV-treatment containing lamivudine (n = 53) or tenofovir (n = 33), had available baseline pc sequences. Association of the pcG1896A mutation with time to undetectable HBV-DNA, hepatitis B "e" antigen (HBeAg) seroclearance (in HBeAg-positive patients), and hepatitis B surface antigen (HBsAg) seroclearance was evaluated using Cox proportional hazards regression. At ARV-initiation, median HBV-DNA was 6.04 log10 copies/mL (IQR = 3.70-7.93) with 97.7% harbouring HBV genotype E. Baseline pcG1896A mutation was identified in 51 (59.3%) patients, who were more commonly HBeAg-negative (P < .001) and had basal core promotor A1762T/G1764A mutations (P < .001). Patients were followed for a median 36 months (IQR = 24-36). Cumulative proportion of undetectable HBV-DNA was significantly higher in patients with baseline mutation (pcG1896A = 86.6% vs no pcG1896A = 66.9%, P = .04), but not after adjusting for baseline HBV-DNA levels and anti-HBV agent (P = .2). No difference in cumulative proportion of HBeAg seroclearance was observed between mutation groups (pcG1896A = 57.1% vs no pcG1896A = 54.3%, P = .7). Significantly higher cumulative proportion of HBsAg seroclearance was observed in patients without this mutation (pcG1896A = 0% vs no pcG1896A = 36.9%, P < .001), even after adjusting for baseline HBsAg quantification and anti-HBV agent (P < .001). In conclusion, lacking the pcG1896A mutation before ARV initiation appeared to increase HBsAg seroclearance rates during treatment. The therapeutic implications of this mutation need further exploration in this setting.

Prevalence of HIV-1 drug resistance in treated patients with viral load >50 copies/mL: a 2014 French nationwide study.

Background: Surveillance of HIV-1 resistance in treated patients with a detectable viral load (VL) is important to monitor, in order to assess the risk of spread of resistant viruses and to determine the proportion of patients who need new antiretroviral drugs with minimal cross-resistance. Methods: The HIV-1 protease and reverse transcriptase (RT) and integrase genes were sequenced in plasma samples from 782 consecutive patients on failing antiretroviral regimens, seen in 37 specialized centres in 2014. The genotyping results were interpreted using the ANRS v24 algorithm. Prevalence rates were compared with those obtained during a similar survey conducted in 2009. Results: The protease and RT sequences were obtained in 566 patients, and the integrase sequence in 382 patients. Sequencing was successful in 60%, 78%, 78% and 87% of patients with VLs of 51-200, 201-500, 501-1000 and >1000 copies/mL, respectively. Resistance to at least one antiretroviral drug was detected in 56.3% of samples. Respectively, 3.9%, 8.7%, 1.5% and 3.4% of patients harboured viruses that were resistant to any NRTI, NNRTI, PI and integrase inhibitor (INI). Resistance rates were lower in 2014 than in 2009. Resistance was detected in 48.5% of samples from patients with a VL between 51 and 200 copies/mL. Conclusion: In France in 2014, 90.0% of patients in AIDS care centres were receiving antiretroviral drugs and 12.0% of them had VLs >50 copies/mL. Therefore, this study suggests that 6.7% of treated patients in France might transmit resistant strains. Resistance testing may be warranted in all treated patients with VL > 50 copies/mL.

Pre-exposure prophylaxis: a useful tool to prevent human immunodeficiency virus infection?

The aim of preventive measures against human immunodeficiency virus (HIV) is to reduce the incidence of HIV infection in the general population and in high-risk groups, such as men having sex with men (MSM), and to reduce the risk that a given individual will contract or spread the virus. Male and female condoms, post-exposure prophylaxis and circumcision are preventive methods currently recognized or promoted worldwide. Although modest success has been reported in a phase-III vaccine trial, other methods are being evaluated, such as vaginal and rectal microbicides, and pre-exposure prophylaxis (PrEP). Herein, we discuss results from prevention trials, especially those focusing on PrEP and particularly on recent results from 'on-demand' PrEP regimens. The efficacy of PrEP (rates of 0%-86%) is strongly correlated with adherence and plasma concentrations of antiretrovirals. Adverse events are rare. Selection of emtricitabine-resistant strains is mainly reported in individuals with an undiagnosed HIV infection using PrEP. PrEP is now strongly recommended in WHO prevention programmes for individuals at substantial risk for HIV with a view to controlling this epidemic by 2030.

Intensification with pegylated interferon during treatment with tenofovir in HIV-hepatitis B virus co-infected patients.

In hepatitis B "e" antigen (HBeAg) positive patients with hepatitis B virus (HBV) mono-infection, intensification of nucleos(t)ide analogue treatment with pegylated interferon (PegIFN) could help induce higher HBeAg seroclearance rates. Our aim was to determine the long-term effect of adding PegIFN to tenofovir (TDF)-containing antiretroviral therapy on seroclearance in HBeAg-positive patients co-infected with the human immunodeficiency virus (HIV) and HBV. In this prospective matched cohort study, 46 patients with 1-year PegIFN intensification during TDF-containing antiretroviral therapy (TDF+PegIFN) were matched 1:1 to controls undergoing TDF without PegIFN (TDF) using a time-dependent propensity score based on age, CD4+ count and liver cirrhosis status. Kinetics of HBeAg quantification (qHBeAg) and hepatitis B surface antigen quantification (qHBsAg) were estimated using mixed-effect linear regression and time to HBeAg seroclearance or HBsAg seroclearance was modelled using proportional hazards regression. At baseline, previous TDF exposure was a median 39.8 months (IQR=21.4-59.4) and median qHBeAg and qHBsAg levels were 6.9 PEIU/mL and 3.72 log10 IU/mL, respectively (P>.5 between groups). Median follow-up was 33.4 months (IQR=19.0-36.3). During intensification, faster average declines of qHBeAg (-0.066 vs -0.027 PEIU/mL/month, P=.001) and qHBsAg (-0.049 vs -0.026 log10 IU/mL/month, P=.09) were observed in patients undergoing TDF+PegIFN vs TDF, respectively. After intensification, qHBeAg and qHBsAg decline was no different between groups (P=.7 and P=.9, respectively). Overall, no differences were observed in HBeAg seroclearance (TDF+PegIFN=13.2 vs TDF=12.6/100 person·years, P=.5) or HBsAg seroclearance rates (TDF+PegIFN=1.8 vs TDF=1.3/100 person·years, P=.7). In conclusion, PegIFN intensification in HBeAg-positive co-infected patients did not lead to increased rates of HBeAg or HBsAg clearance, despite faster declines of antigen levels while on PegIFN.

HIV-1 subtype influences susceptibility and response to monotherapy with the protease inhibitor lopinavir/ritonavir.

OBJECTIVE: PI susceptibility results from a complex interplay between protease and Gag proteins, with Gag showing wide variation across HIV-1 subtypes. We explored the impact of pre-treatment susceptibility on the outcome of lopinavir/ritonavir monotherapy. METHODS: Treatment-naive individuals who experienced lopinavir/ritonavir monotherapy failure from the MONARK study were matched (by subtype, viral load and baseline CD4 count) with those who achieved virological response ('successes'). Successes were defined by viral load <400 copies/mL after week 24 and <50 copies/mL from week 48 to week 96. Full-length Gag-protease was amplified from patient samples for in vitro phenotypic susceptibility testing, with susceptibility expressed as fold change (FC) relative to a subtype B reference strain. RESULTS: Baseline lopinavir susceptibility was lower in viral failures compared with viral successes, but the differences were not statistically significant (median lopinavir susceptibility: 4.4 versus 8.5, respectively, P = 0.17). Among CRF02_AG/G patients, there was a significant difference in lopinavir susceptibility between the two groups (7.1 versus 10.4, P = 0.047), while in subtype B the difference was not significant (2.7 versus 3.4, P = 0.13). Subtype CRF02_AG/G viruses had a median lopinavir FC of 8.7 compared with 3.1 for subtype B (P = 0.001). CONCLUSIONS: We report an association between reduced PI susceptibility (using full-length Gag-protease sequences) at baseline and subsequent virological failure on lopinavir/ritonavir monotherapy in antiretroviral-naive patients harbouring subtype CRF02_AG/G viruses. We speculate that this may be important in the context of suboptimal adherence in determining viral failure.

Archived HIV-1 DNA resistance mutations to rilpivirine and etravirine in successfully treated HIV-1-infected individuals pre-exposed to efavirenz or nevirapine.

OBJECTIVES: Efavirenz and nevirapine failure is associated with a rapid selection of resistance-associated mutations (RAMs), which may impact on etravirine or rilpivirine susceptibility. However, RAMs for rilpivirine and etravirine cannot be reported on previous resistance genotypes because these specific RAMs were not analyzed at that time. Therefore, our objective was to determine, in virologically suppressed HIV-1-infected individuals, the presence of RAMs to rilpivirine, etravirine and the combination of tenofovir/emtricitabine/rilpivirine in HIV-1 DNA from individuals previously exposed to efavirenz and/or nevirapine. METHODS: The studied population included 169 treatment-experienced individuals enrolled in the ANRS 138-EASIER trial who previously failed on and/or were intolerant to efavirenz and/or nevirapine and who had plasma HIV-1 RNA<400 copies/mL. Resistance to rilpivirine, etravirine, tenofovir and emtricitabine by bulk sequencing was performed on extracted HIV-1 DNA from whole blood collected at the time of trial inclusion. RESULTS: Reverse transcriptase gene amplification was successful in 128/169 (76%) individuals and 95% of HIV-1 were infected with subtype B. Rilpivirine RAMs were detected in 41 (32%) individuals, with highest frequency for the mutations Y181C/I/V (18%), K101E/P (7%) and E138A/G/K/Q/R/S (6%) and the association L100I+K103N/S (5%). Etravirine RAMs were detected in five (4%) individuals. Resistance to emtricitabine, tenofovir and at least one drug included in the combination of tenofovir/emtricitabine/rilpivirine were detected in 72 (56%), 12 (9%) and 88 (69%), respectively. CONCLUSIONS: In individuals with suppressed viraemia under antiretroviral therapy (ART), but who had been previously exposed to an efavirenz and/or nevirapine-based regimen, rilpivirine RAMs are frequent and etravirine RAMs are rare. This finding suggests that the switch to a rilpivirine-based regimen should not be recommended.

An undetectable polymerase chain reaction signal in routine HIV plasma viral load monitoring is associated with better virological outcomes in patients receiving highly active antiretroviral therapy.

OBJECTIVES: The aim of the study was to assess whether patients with undetectable viraemia [a negative polymerase chain reaction result (PCR(neg) )] and those with plasma viral load (PVL) < 40 HIV-1 RNA copies/mL but a detectable (positive) PCR signal (PCR(pos) ) had different outcomes in terms of the development of blips and virological failure (VF). METHODS: A multicentre observational database analysis was carried out. Data for patients whose highly active antiretroviral therapy (HAART) regime had been unchanged for ≥ 6 months by 1 January 2008, whose first two PVL measurements of 2008 were < 40 copies/mL and who had at least five PVL measurements between 1 January 2008 and 31 December 2010 were extracted from a multicentre observational database of 4928 patients receiving HAART. PVL assays used during this period had a detection threshold of 20 or 40 copies/mL. Undetectable PVL at baseline (BL PCR(neg) ) was defined as PCR(neg) at the first two PVL determinations of 2008. Multivariable Cox regression analysis was performed to investigate factors associated with the occurrence of blips and VF, defined as two consecutive PVL measurements > 40 copies/mL. RESULTS: Of the 1957 patients included in the study (mean age 47 years; median antiretroviral exposure 10.3 years), 1312 had BL PCR(neg) . Outcome events included 322 blips and 139 VFs, with incidence rates being significantly lower in patients with BL PCR(neg) than in those with BL PCR(pos) [13.0% vs. 23.4% (P < 0.0001) and 5.1% vs. 11.2% (P < 0.0001), respectively]. In multivariable analysis, BL PCR(neg) was associated with a reduced risk of blips [hazard ratio (HR) 0.58; 95% confidence interval (CI) 0.47-0.73; P < 0.0001] and VF (HR 0.44; 95% CI 0.31-0.62; P < 0.0001). CONCLUSIONS: Patients with PCR(neg) had better virological outcomes than those with PVL < 40 copies/mL but detectable viraemia. This suggests that the 'no-signal' information provided by currently commercially available HIV RNA quantification assays should be used routinely.

Analytical sensitivity of three real-time PCR assays for measuring subtype B HIV-1 RNA.

BACKGROUND: Lack of HIV RNA during antiretroviral therapy (ART) is regarded as a desirable outcome. Commercial assays of HIV virus load now need to detect virus RNA concentrations below 50 c/ml and several of them have claimed a limit of detection (LOD) of 20-45 c/ml. OBJECTIVES AND STUDY DESIGN: We have compared the performances of three commercial assays of HIV RNA, the Abbott RealTime HIV-1, the Qiagen Artus RG HIV-1 and the Roche Cobas Ampliprep Cobas TaqMan (CAPCTM) HIV-1 vs 2.0 using replicate of specimens with HIV-1 subtype B RNA concentrations of 20-200 c/ml. RESULTS: Despite fair-to-moderate agreement between the three assays, probit analysis showed that their LODs differed; they were 81, 65 and 18c/ml respectively. The CAPCTM HIV-1 vs 2.0 values were higher than those of the other two; the maximum difference was 0.26 log c/ml. By testing 20 replicate of each concentration, coefficients of variation were between 0.6% and 9.2% (Abbott RealTime HIV-1), 10.3% and 38% (Qiagen Artus RG HIV-1) and 5.2% and 13.1% (Roche CAPCTM HIV-1 vs 2.0). The three assays also differed in their reproducibility and linearity for virus loads of 50-200 c/ml. CONCLUSION: The analytical performances of commercial virus load assays differ. Direct comparisons of widely used commercial assays in clinical studies could help to identify the residual viremia that is clinically relevant for effective long term therapy.

Longitudinal analysis of integrase N155H variants in heavily treated patients failing raltegravir-based regimens.

OBJECTIVES: The mechanism of raltegravir (RAL)-resistant evolutions has not already been elucidated. Because the emergence of RAL resistance is usually initiated by the N155H mutant, we assessed the role of minor N155H-mutated variants in circulating RNA and archived DNA in five heavily treated patients experiencing long-term RAL therapy failure and harbouring three different resistance profiles determined by standard genotyping. METHODS: Allele-specific polymerase chain reaction (AS-PCR) was used to detect N155H mutants in longitudinal stored plasma and whole-blood samples before, during and after RAL-based regimens in five patients infected with the HIV-1 B subtype. RESULTS: No minor N155H-mutated variant was found by AS-PCR in either plasma or whole-blood samples collected at baseline and after RAL withdrawal in any of the five patients. During RAL failure, the mutation N155H was detected at different levels in three patients displaying the N155H pathway and gradually declined when the double mutant Q148H+G140S was selected in one patient. In two patients with the Q148H resistance pathway, no N155H variant was identified by AS-PCR in either viral RNA or DNA. CONCLUSIONS: The N155H mutation present at various levels from minority to majority showed no relationship with the three RAL-associated resistance profiles, suggesting that this mutant may not play a role in determining different resistance profiles. Moreover, pre-existing N155H is very infrequent and, if selected during RAL failure, the N155H mutant disappears quickly after RAL withdrawal.

Comparison of resistance mutation patterns in historical plasma HIV RNA genotypes with those in current proviral HIV DNA genotypes among extensively treated patients with suppressed replication.

OBJECTIVES: Heavily treatment-experienced patients with good virological control could be at risk of virological failure on switching to a new regimen if pre-existing drug resistance is not taken into account. We examined whether genotyping based on cellular HIV-1 DNA during controlled viraemia identifies resistance mutations detected in plasma HIV-1 RNA during treatment with previous antiretroviral regimens. PATIENTS AND METHODS: All 169 patients enrolled in the Agence Nationale de Recherche sur le SIDA (ANRS) 138-intEgrase inhibitor MK_0518 to Avoid Subcutaneous Injections of EnfuviRtide (EASIER) trial had already received three antiretroviral drug classes [nucleoside reverse transcriptase inhibitor (NRTI), nonnucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitor (PI)] and had plasma HIV-1 RNA<400 copies/ml at baseline. The results of previous resistance genotyping of plasma HIV-1 RNA in individual patients were compared with those of resistance genotyping of whole-blood HIV-1 DNA at randomization. RESULTS: A median of 4 plasma RNA genotypes were available for the 169 patients. The median numbers of resistance mutations in HIV-1 RNA and DNA were, respectively, 5 and 4 for NRTIs, 2 and 1 for NNRTIs, and 10 and 8 for PIs. The difference was significant for all three drug classes (P=0.001). Resistance to at least one antiretroviral drug was detected exclusively in HIV-1 RNA or in DNA in 63% and 13% of patients for NRTI, 47% and 1% of patients for NNRTI, and 50% and 7% of patients for PI, respectively. CONCLUSION: This study shows that, among highly treatment-experienced patients on effective highly active antiretroviral therapy, resistance genotyping of HIV-1 DNA detects fewer resistance mutations than previous analyses of HIV-1 RNA. These results have implications for patient management and for the design of switch studies.

[Genetic barrier to antiretroviral drug-resistance. Focus on raltegravir, the first integrase inhibitor]. / Barrière génétique à la résistance des antirétroviraux. Le point sur le raltégravir, premier inhibiteur d'intégrase.

The genetic barrier for the antiretroviral describes the ability to select resistant viruses to this antiretroviral when the viral replication is not controlled. This includes combining several concepts: (1) the number of nucleotide changes required for a resistance mutation, (2) the impact of this mutation on the level of susceptibility to antiretroviral (3) the impact of this mutation on viral replication capacity; all theses conditions influencing the level of resistant variants. The antiretroviral concentration impact also the emergence of resistance. Finally, combine with other molecules, the selection of resistance mutations ton an antiretroviral may differ from one treatment to another. It is recognized that the genetic barrier to lamivudine/emtricitabine, efavirenz and nevirapine is low, and is intermediate for nucleoside such as zidovudine and tenofovir. However, ritonavir boosted protease inhibitor with high plasma concentration have a high genetic barrier. For integrase inhibitors such as raltegravir, the emergence of resistance is certainly faster than the ritonavir boosted protease inhibitors, but seems slower and less systematic than for efavirenz or lamivudine. Many factors could influence the raltegravir resistance such as the level of viral load and replication duration, genetic polymorphism of HIV (integrase gene and other, viral subtype) and the plasma and/or intra- cellular raltegravir concentration.

Factors predictive of successful darunavir/ritonavir-based therapy in highly antiretroviral-experienced HIV-1-infected patients (the DARWEST study).

BACKGROUND: Darunavir (DRV) is the latest protease inhibitor (PI) to be approved for antiretroviral-naive and -experienced HIV-infected patients. OBJECTIVES: We examined virologic and immunologic outcomes of highly antiretroviral-experienced patients with triple-class drug resistance receiving DRV/r-based regimens, and attempted to identify factors predictive of virologic success. STUDY DESIGN: We studied patients beginning a ritonavir-boosted DRV (DRV/r 600/100mg twice daily)-containing regimen. Virologic success was defined as plasma viral load (pVL)<50copies/ml at week 36. RESULTS: We studied 62 patients with very severe immunodeficiency (CDC stage C in 69% of cases; median CD4 cell nadir 12/mm(3)). They had previously received a median of four PI and had extensive PI resistance, with a median of three major PI and two DRV resistance mutations. The baseline median pVL and CD4 cell count values were 4.6log(10) and 150/mm(3). At week 36, pVL had fallen by 2.6log(10) and the CD4 cell count had risen by 123cells/mm(3). The virologic success rate was 55% overall, and was improved by concomitant first use of enfuvirtide (67%), raltegravir (69%) or etravirine (75%). Virologic success was independently associated with fewer major PI mutations, previous tipranavir exposure, and concomitant first use of enfuvirtide or raltegravir. CONCLUSIONS: In these highly antiretroviral-experienced patients with triple-class drug resistance, virologic success of DRV-containing regimens was mainly associated with the use of new drug classes and/or fully active drugs. Interestingly, previous tipranavir failure did not undermine the efficacy of DRV, confirming the low level of cross-resistance and, probably, distinct resistance profiles between DRV and tipranavir.