Addressing pandemic-wide systematic errors in the SARS-CoV-2 phylogeny

The SARS-CoV-2 genome occupies a unique place in infection biology - it is the most highly sequenced genome on earth (making up over 20% of public sequencing datasets) with fine scale information on sampling date and geography, and has been subject to unprecedented intense analysis. As a result, these phylogenetic data are an incredibly valuable resource for science and public health. However, the vast majority of the data was sequenced by tiling amplicons across the full genome, with amplicon schemes that changed over the pandemic as mutations in the viral genome interacted with primer binding sites. In combination with the disparate set of genome assembly workflows and lack of consistent quality control (QC) processes, the current genomes have many systematic errors that have evolved with the virus and amplicon schemes. These errors have significant impacts on the phylogeny, and therefore over the last few years, many thousands of hours of researchers time has been spent in "eyeballing" trees, looking for artefacts, and then patching the tree. Given the huge value of this dataset, we therefore set out to reprocess the complete set of public raw sequence data in a rigorous amplicon-aware manner, and build a cleaner phylogeny. Here we provide a global tree of 3,960,704 samples, built from a consistently assembled set of high quality consensus sequences from all available public data as of March 2023, viewable at https://viridian.taxonium.org . Each genome was constructed using a novel assembly tool called Viridian ( https://github.com/iqbal-lab-org/viridian ), developed specifically to process amplicon sequence data, eliminating artefactual errors and mask the genome at low quality positions. We provide simulation and empirical validation of the methodology, and quantify the improvement in the phylogeny. Phase 2 of our project will address the fact that the data in the public archives is heavily geographically biased towards the Global North. We therefore have contributed new raw data to ENA/SRA from many countries including Ghana, Thailand, Laos, Sri Lanka, India, Argentina and Singapore. We will incorporate these, along with all public raw data submitted between March 2023 and the current day, into an updated set of assemblies, and phylogeny. We hope the tree, consensus sequences and Viridian will be a valuable resource for researchers.

Use of genotypic HIV DNA testing: a DELPHI-type consensus

OBJECTIVES

As many disparities in the clinical use of HIV DNA sequencing are observed, a DELPHI-type consensus was initiated in France to homogenize use, techniques and interpretation of results.

METHODS

Based on a literature review and clinical experience, a steering committee (SC) of eight virologists and one infectious disease specialist formulated statements. Statements were submitted to an independent and anonymous electronic vote of virologists and HIV clinicians in France, between October 2022 and December 2022.

RESULTS

The SC developed 20 statements grouped into six categories: clinical situations for the use of HIV DNA genotyping; techniques for performing HIV DNA genotyping; consideration of apolipoprotein B mRNA editing enzyme (APOBEC) mutations; genotyping results reporting; recycling of antiretrovirals; and availability of HIV DNA genotyping tests and delays. Twenty-one virologists and 47 clinicians participated in two voting rounds and 18/20 (90%) assertions reached a 'strong' consensus. For example, that prior genotyping on HIV DNA is useful for clinical decision-making when considering switching to some long-acting regimens or to reduce the number of antiretroviral agents in virologically suppressed patients for whom RNA data are unavailable/not exploitable/not sufficiently informative. Two statements achieved no consensus: reporting any detected viral minority population for discussion in multidisciplinary meetings (virologists), and possible risk of virological failure when using a second-generation InSTI plus lamivudine or emtricitabine regimen in patients with undetectable viral load within ≥1 year and in the presence of a documented M184V mutation within the last 5 years (clinicians).

CONCLUSIONS

This DELPHI-type consensus will facilitate the strengthening and harmonization of good practice when performing HIV DNA sequencing.

Receptor binding domain-IgG levels correlate with protection in residents facing SARS-CoV-2 B.1.1.7 outbreaks

Background

Limited information exists on nursing home (NH) residents regarding BNT162b2 vaccine efficacy in preventing SARS‐CoV‐2 and severe COVID‐19, and its association with post‐vaccine humoral response.

Methods

396 residents from seven NHs suffering a SARS‐CoV‐2 B.1.1.7 (VOC‐α) outbreak at least 14 days after a vaccine campaign were repeatedly tested using SARS‐CoV‐2 real‐time reverse‐transcriptase polymerase chain reaction on nasopharyngeal swab test (RT‐qPCR). SARS‐CoV‐2 receptor‐binding domain (RBD) of the S1 subunit (RBD‐IgG) was measured in all residents. Nucleocapsid antigenemia (N‐Ag) was measured in RT‐qPCR‐positive residents and serum neutralizing antibodies in vaccinated residents from one NH.

Results

The incidence of positive RT‐qPCR was lower in residents vaccinated by two doses (72/317; 22.7%) vs one dose (10/31; 32.3%) or non‐vaccinated residents (21/48; 43.7%; p < .01). COVID‐19–induced deaths were observed in 5 of the 48 non‐vaccinated residents (10.4%), in 2 of the 31 who had received one dose (6.4%), and in 3 of the 317 (0.9%) who had received two doses (p = .0007). Severe symptoms were more common in infected non‐vaccinated residents (10/21; 47.6%) than in infected vaccinated residents (15/72; 21.0%; p = .002). Higher levels of RBD‐IgG (n = 325) were associated with a lower SARS‐CoV‐2 incidence. No in vitro serum neutralization activity was found for RBD‐IgG levels below 1050 AU/ml. RBD‐IgG levels were inversely associated with N‐Ag levels, found as a risk factor of severe COVID‐19.

Conclusions

Two BNT162b2 doses are associated with a 48% reduction of SARS‐CoV‐2 incidence and a 91.3% reduction of death risk in residents from NHs facing a VOC‐α outbreak. Post‐vaccine RBD‐IgG levels correlate with BNT162b2 protection against SARS‐CoV‐2 B.1.1.7.

Characterization of viral rebounds on dual etravirine/raltegravir maintenance therapy (ANRS-163 ETRAL trial)

BACKGROUND

The ANRS-163 ETRAL trial, a switch study to an etravirine 200 mg/raltegravir 400 mg twice-daily regimen in 165 patients with HIV-1 infection, showed durable efficacy until Week 96. The aim of this work was to investigate in detail the virological rebounds (VRs), defined as at least one plasma HIV viral load (VL) >50 copies/mL.

METHODS

Quantification of HIV-DNA level was assessed at baseline, Week 48 and Week 96 (n = 157). VLs were measured in seminal plasma at Week 48 (n = 26). Genotypic resistance testing by ultra-deep sequencing (UDS) for reverse transcriptase (RT) and integrase regions was performed at baseline and at the time of VR.

RESULTS

In this study, 19 patients experienced VR, with 2 patients having virological failure (VF; two consecutive VLs >50 copies/mL). For the first patient with VF, UDS detected minority resistant variants only in RT (K103N, 9.6%; Y181C, 4.9%) at baseline. Some RT variants became dominant at VF (K101E, 86.3%; Y181C, 100.0%; G190A, 100.0%) and others emerged in integrase (Y143C, 2.4%; Q148R, 6.2%; N155H, 18.8%). For the second patient with VF, neither RT nor integrase mutations were detected at baseline and VF. Median HIV-DNA level was similar at baseline, Week 48 and Week 96 (2.17, 2.06 and 2.11 log10 copies/106 cells, respectively). Only one patient had a detectable seminal HIV VL (505 copies/mL).

CONCLUSIONS

The dual etravirine/raltegravir regimen as maintenance therapy was effective and the emergence of mutations in cases of VF was similar to that seen in other dual-regimen studies. No HIV-DNA level modification was evidenced by Week 96.

Factors associated with the emergence of integrase resistance mutations in patients failing dual or triple integrase inhibitor-based regimens in a French national survey

BACKGROUND

Successful 2-drug regimens (2DRs) for HIV were made possible by the availability of drugs combining potency and tolerability with a high genetic barrier to resistance. How these deal with resistance development/re-emergence, compared with 3DRs, is thus of paramount importance.

MATERIALS AND METHODS

A national survey including patients who were either naive or experienced with any 2DR or 3DR but failing integrase strand transfer inhibitor (INSTI)-containing regimens [two consecutive plasma viral load (VL) values >50 copies/mL] was conducted between 2014 and 2019. Genotypic resistance tests were interpreted with the v28 ANRS algorithm.

RESULTS

Overall, 1104 patients failing any INSTI-containing regimen (2DRs, n = 207; 3DRs, n = 897) were analysed. Five hundred and seventy-seven (52.3%) patients were infected with a B subtype and 527 (47.3%) with non-B subtypes. Overall, 644 (58%) patients showed no known integrase resistance mutations at failure. In multivariate analysis, factors associated with the emergence of at least one integrase mutation were: high VL at failure (OR = 1.24 per 1 log10 copies/mL increase); non-B versus B subtype (OR = 1.75); low genotypic sensitivity score (GSS) (OR = 0.10 for GSS = 2 versus GSS = 0-0.5); and dolutegravir versus raltegravir (OR = 0.46). Although 3DRs versus 2DRs reached statistical significance in univariate analysis (OR = 0.59, P = 0.007), the variable is not retained in the final model.

CONCLUSIONS

This study is one of the largest studies characterizing integrase resistance in patients failing any INSTI-containing 2DR or 3DR in routine clinical care and reveals factors associated with emergence of integrase resistance that should be taken into consideration in clinical management. No difference was evidenced between patients receiving a 2DR or a 3DR.

Surveillance of HIV-1 primary infections in France from 2014 to 2016: toward stable resistance, but higher diversity, clustering and virulence?

OBJECTIVES

Patients with primary HIV-1 infection (PHI) are a particular population, giving important insight about ongoing evolution of transmitted drug resistance-associated mutation (TDRAM) prevalence, HIV diversity and clustering patterns. We describe these evolutions of PHI patients diagnosed in France from 2014 to 2016.

METHODS

A total of 1121 PHI patients were included. TDRAMs were characterized using the 2009 Stanford list and the French ANRS algorithm. Viral subtypes and recent transmission clusters (RTCs) were also determined.

RESULTS

Patients were mainly MSM (70%) living in the Paris area (42%). TDRAMs were identified among 10.8% of patients and rose to 18.6% when including etravirine and rilpivirine TDRAMs. Prevalences of PI-, NRTI-, first-generation NNRTI-, second-generation NNRTI- and integrase inhibitor-associated TDRAMs were 2.9%, 5.0%, 4.0%, 9.4% and 5.4%, respectively. In a multivariable analysis, age >40 years and non-R5 tropic viruses were associated with a >2-fold increased risk of TDRAMs. Regarding HIV diversity, subtype B and CRF02_AG (where CRF stands for circulating recombinant form) were the two main lineages (56% and 20%, respectively). CRF02_AG was associated with higher viral load than subtype B (5.83 versus 5.40 log10 copies/mL, P=0.004). We identified 138 RTCs ranging from 2 to 14 patients and including overall 41% from the global population. Patients in RTCs were younger, more frequently born in France and more frequently MSM.

CONCLUSIONS

Since 2007, the proportion of TDRAMs has been stable among French PHI patients. Non-B lineages are increasing and may be associated with more virulent CRF02_AG strains. The presence of large RTCs highlights the need for real-time cluster identification to trigger specific prevention action to achieve better control of the epidemic.

Modeling SARS-CoV-2 viral kinetics and association with mortality in hospitalized patients from the French COVID cohort

The characterization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral kinetics in hospitalized patients and its association with mortality is unknown. We analyzed death and nasopharyngeal viral kinetics in 655 hospitalized patients from the prospective French COVID cohort. The model predicted a median peak viral load that coincided with symptom onset. Patients with age ≥65 y had a smaller loss rate of infected cells, leading to a delayed median time to viral clearance occurring 16 d after symptom onset as compared to 13 d in younger patients (P < 10-4). In multivariate analysis, the risk factors associated with mortality were age ≥65 y, male gender, and presence of chronic pulmonary disease (hazard ratio [HR] > 2.0). Using a joint model, viral dynamics after hospital admission was an independent predictor of mortality (HR = 1.31, P < 10-3). Finally, we used our model to simulate the effects of effective pharmacological interventions on time to viral clearance and mortality. A treatment able to reduce viral production by 90% upon hospital admission would shorten the time to viral clearance by 2.0 and 2.9 d in patients of age <65 y and ≥65 y, respectively. Assuming that the association between viral dynamics and mortality would remain similar to that observed in our population, this could translate into a reduction of mortality from 19 to 14% in patients of age ≥65 y with risk factors. Our results show that viral dynamics is associated with mortality in hospitalized patients. Strategies aiming to reduce viral load could have an effect on mortality rate in this population.

Diagnosis value of SARS-CoV-2 antigen/antibody combined testing using rapid diagnostic tests at hospital admission

The implementation of rapid diagnostic tests (RDTs) may enhance the efficiency of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) testing, as RDTs are widely accessible and easy to use. The aim of this study was to evaluate the performance of a diagnosis strategy based on a combination of antigen and immunoglobulin M (IgM) or immunoglobulin G (IgG) serological RDTs. Plasma and nasopharyngeal samples were collected between 14 March and 11 April 2020 at hospital admission from 45 patients with reverse transcription polymerase chain reaction (RT‐PCR) confirmed COVID‐19 and 20 negative controls. SARS‐CoV‐2 antigen (Ag) was assessed in nasopharyngeal swabs using the Coris Respi‐Strip. For IgM/IgG detection, SureScreen Diagnostics and Szybio Biotech RDTs were used in addition to laboratory assays (Abbott Alinity i SARS‐CoV‐2 IgG and Theradiag COVID‐19 IgM enzyme‐linked immunosorbent assay). Using the Ag RDT, 13 out of 45 (29.0%) specimens tested positive, the sensitivity was 87.0% for cycle threshold (C_t) values ≤25% and 0% for C_t values greater than 25. IgG detection was associated with high C_t values and the amount of time after the onset of symptoms. The profile of isolated IgM on RDTs was more frequently observed during the first and second week after the onset of symptoms. The combination of Ag and IgM/IgG RDTs enabled the detection of up to 84.0% of COVID‐19 confirmed cases at hospital admission. Antigen and antibody‐based RDTs showed suboptimal performances when used alone. However when used in combination, they are able to identify most COVID‐19 patients admitted in an emergency department.

‐

Antigen and antibody‐based RDTs showed suboptimal performances when used alone.

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The Ag RDT showed good sensitivity on samples with CT values below 25.

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IgM/IgG RDTs showed good sensitivity as of the second week after onset of symptoms.

‐

The combination of Ag and IgM/IgG RDTs identified most patients with COVID‐19.

‐

RDTs may have a significant place in the global response to the COVID‐19 pandemic.

Microelimination or Not? The Changing Epidemiology of Human Immunodeficiency Virus-Hepatitis C Virus Coinfection in France 2012–2018

Background

The arrival of highly effective, well-tolerated, direct-acting antiviral agents (DAA) led to a dramatic decrease in hepatitis C virus (HCV) prevalence. Human immunodeficiency virus (HIV)-HCV–coinfected patients are deemed a priority population for HCV elimination, while a rise in recently acquired HCV infections in men who have sex with men (MSM) has been described. We describe the variations in HIV-HCV epidemiology in the French Dat’AIDS cohort.

Methods

This was a retrospective analysis of a prospective cohort of persons living with HIV (PLWH) from 2012 to 2018. We determined HCV prevalence, HCV incidence, proportion of viremic patients, treatment uptake, and mortality rate in the full cohort and by HIV risk factors.

Results

From 2012 to 2018, 50 861 PLWH with a known HCV status were followed up. During the period, HCV prevalence decreased from 15.4% to 13.5%. HCV prevalence among new HIV cases increased from 1.9% to 3.5% in MSM but remained stable in other groups. Recently acquired HCV incidence increased from 0.36/100 person-years to 1.25/100 person-years in MSM. The proportion of viremic patients decreased from 67.0% to 8.9%. MSM became the first group of viremic patients in 2018 (37.9%). Recently acquired hepatitis represented 59.2% of viremic MSM in 2018. DAA treatment uptake increased from 11.4% to 61.5%. More treatments were initiated in MSM in 2018 (41.2%) than in intravenous drug users (35.6%). In MSM, treatment at the acute phase represented 30.0% of treatments in 2018.

Conclusions

A major shift in HCV epidemiology was observed in PLWH in France from 2012 to 2018, leading to a unique situation in which the major group of HCV transmission in 2018 was MSM.

Clinical Trials Registration. NCT02898987.

Stable prevalence of transmitted drug resistance mutations and increased circulation of non-B subtypes in antiretroviral-naive chronically HIV-infected patients in 2015/2016 in France

OBJECTIVES

We estimated the prevalence of transmitted-drug-resistance-associated mutations (TDRAMs) in antiretroviral-naive chronically HIV-1-infected patients.

PATIENTS AND METHODS

TDRAMs were sought in samples from 660 diagnosed HIV-1-infected individuals in 2015/2016 in 33 HIV clinical centres. Weighted analyses, considering the number of patients followed in each centre, were used to derive representative estimates of the percentage of individuals with TDRAMs. Results were compared with those of the 2010/2011 survey (n = 661) using the same methodology.

RESULTS

At inclusion, median CD4 cell counts and plasma HIV-1 RNA were 394 and 350/mm3 (P = 0.056) and 4.6 and 4.6 log10 copies/mL (P = 0.360) in the 2010/2011 survey and the 2015/2016 survey, respectively. The frequency of non-B subtypes increased from 42.9% in 2010/2011 to 54.8% in 2015/2016 (P < 0.001), including 23.4% and 30.6% of CRF02_AG (P = 0.004). The prevalence of virus with protease or reverse-transcriptase TDRAMs was 9.0% (95% CI = 6.8-11.2) in 2010/2011 and 10.8% (95% CI = 8.4-13.2) in 2015/2016 (P = 0.269). No significant increase was observed in integrase inhibitor TDRAMs (6.7% versus 9.2%, P = 0.146). Multivariable analysis showed that men infected with the B subtype were the group with the highest risk of being infected with a resistant virus compared with others (adjusted OR = 2.2, 95% CI = 1.3-3.9).

CONCLUSIONS

In France in 2015/2016, the overall prevalence of TDRAMs was 10.8% and stable compared with 9.0% in the 2010/2011 survey. Non-B subtypes dramatically increased after 2010. Men infected with B subtype were the group with the highest risk of being infected with a resistant virus, highlighting the need to re-emphasize safe sex messages.

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.

Phenotypic analysis of HIV-1 E157Q integrase polymorphism and impact on virological outcome in patients initiating an integrase inhibitor-based regimen

Objectives

To assess the phenotypic susceptibility of the E157Q polymorphism in HIV-1 integrase (IN) and the virological outcome of patients infected with E157Q-mutated virus initiating an IN inhibitor (INI)-based regimen.

Methods

This was a multicentre study assessing IN sequences from INI-naive patients among 17 French HIV clinical centres. E157Q site-directed mutants in pNL4.3 and pCRF02_AG contexts were assessed in a recombinant phenotypic assay.

Results

Prevalence of the E157Q polymorphism was 2.7% among 8528 IN sequences from INI-naive patients and its distribution was 1.7%, 5.6% and 2.2% in B, CRF02_AG and various non-B subtypes, respectively. Thirty-nine INI-naive patients with E157Q-mutated virus initiated an INI-based regimen. Among them, 15 had a viral load (VL) <50 copies/mL at initiation and virological suppression was maintained during the first year of follow-up in all but two exhibiting a viral blip. Twenty-four patients had a VL > 50 copies/mL at the time of INI-based regimen initiation. Among them eight were receiving a first-line regimen and the only two patients who did not reach VL < 50 copies/mL at week 24 were receiving elvitegravir. The 16 remaining patients were ART experienced in virological failure with drug-resistant viruses displaying several virological outcomes independently of the genotypic susceptibility score. Phenotypic analyses showed a fold change in EC50 of 0.6, 0.9 and 1.9 for raltegravir, dolutegravir and elvitegravir, respectively, in a subtype B context, and 1.1, 1.9 and 2.4 for raltegravir, dolutegravir and elvitegravir, respectively, in a CRF02_AG context.

Conclusions

Assessment of virological response in 39 patients initiating an INI-based regimen with E157Q-mutated virus, in combination with phenotypic analysis, suggests that particular attention should be paid to antiretroviral-naive patients and dolutegravir should be preferentially used in these patients.

HIV-1 DNA ultra-deep sequencing analysis at initiation of the dual therapy dolutegravir + lamivudine in the maintenance DOLULAM pilot study

Background

The DOLULAM study assessed the efficacy of dolutegravir + lamivudine dual therapy to maintain virological suppression in heavily treatment-experienced HIV-1-infected adults. No virological failure occurred during the first year of the dual therapy.

Objectives

A virological substudy was conducted to assess the prevalence of M184I/V mutations at dual therapy initiation using historical DNA/RNA genotypes and baseline DNA genotype obtained by next-generation sequencing (NGS).

Methods

HIV-1 RT sequences were obtained from DNA and/or historical RNA using Sanger technology. HIV-1 DNA RT and integrase NGS was performed using Illumina® technology.

Results

Among the 27 patients enrolled in the DOLULAM study, historical HIV DNA and RNA Sanger sequences were available in 14 and 18 patients, respectively. At the initiation of DOLULAM, DNA NGS genotypes showed that 45% and 21% of the patients harboured minority resistant variants (MRV) in RT and integrase, respectively. Combining all available genotype data, an M184I/V was observed in 17 of 27 (63%) of the patients. Most M184V were detected in historical RNA genotypes (n = 8 of 11), whereas M184I were exclusively detected in DNA genotypes (n = 10, including 7 as MRV). Ten patients displayed defective viral genomes in cellular reservoirs, all including M184I and stop codons. At the time of DOLULAM initiation, M184V was observed in DNA NGS in five patients, including one as MRV.

Conclusions

These first NGS data on HIV DNA at initiation of a switch study showed (i) a high proportion of patients harbouring defective viral genomes, whose mutation M184I is a marker, and (ii) a low number of patients in whom M184V remained as a major viral variant in PBMCs.

Antiretroviral-treated HIV-1 patients can harbour resistant viruses in CSF despite an undetectable viral load in plasma

Background

HIV therapy reduces the CSF HIV RNA viral load (VL) and prevents disorders related to HIV encephalitis. However, these brain disorders may persist in some cases. A large population of antiretroviral-treated patients who had a VL > 1.7 log 10 copies/mL in CSF with detectable or undetectable VL in plasma associated with cognitive impairment was studied, in order to characterize discriminatory factors of these two patient populations.

Methods

Blood and CSF samples were collected at the time of neurological disorders for 227 patients in 22 centres in France and 1 centre in Switzerland. Genotypic HIV resistance tests were performed on CSF. The genotypic susceptibility score was calculated according to the last Agence Nationale de Recherche sur le Sida et les hépatites virales Action Coordonnée 11 (ANRS AC11) genotype interpretation algorithm.

Results

Among the 227 studied patients with VL > 1.7 log 10 copies/mL in CSF, 195 had VL detectable in plasma [median (IQR) HIV RNA was 3.7 (2.7-4.7) log 10 copies/mL] and 32 had discordant VL in plasma (VL < 1.7 log 10 copies/mL). The CSF VL was lower (median 2.8 versus 4.0 log 10 copies/mL; P  <   0.001) and the CD4 cell count was higher (median 476 versus 214 cells/mm 3 ; P  <   0.001) in the group of patients with VL < 1.7 log 10 copies/mL in plasma compared with patients with plasma VL > 1.7 log 10 copies/mL. Resistance to antiretrovirals was observed in CSF for the two groups of patients.

Conclusions

Fourteen percent of this population of patients with cognitive impairment and detectable VL in CSF had well controlled VL in plasma. Thus, it is important to explore CSF HIV (VL and genotype) even if the HIV VL is controlled in plasma because HIV resistance may be observed.

Performance of genotypic algorithms for predicting tropism for HIV-1 CRF01_AE recombinant

OBJECTIVES

There is no consensus about the performances of genotypic rules for predicting HIV-1 non-B subtype tropism. Three genotypic methods were compared for CRF01_AE HIV-1 tropism determination.

METHODS

The V3 env region of 207 HIV-1 CRF01_AE and 178 B subtypes from 17 centers in France and 1 center in Switzerland was sequenced. Tropism was determined by Geno2Pheno algorithm with false positive rate (FPR) 5% or 10%, the 11/25 rule or the combined criteria of the 11/25, net charge rule and NXT/S mutations.

RESULTS

Overall, 72.5%, 59.4%, 86.0%, 90.8% of the 207 HIV-1 CRF01_AE were R5-tropic viruses determined by Geno2pheno FPR5%, Geno2pheno FPR10%, the combined criteria and the 11/25 rule, respectively. A concordance of 82.6% was observed between Geno2pheno FPR5% and the combined criteria for CRF01_AE. The results were nearly similar for the comparison between Geno2pheno FPR5% and the 11/25 rule. More mismatches were observed when Geno2pheno was used with the FPR10%. Neither HIV viral load, nor current or nadir CD4 was associated with the discordance rate between the different algorithms.

CONCLUSION

Geno2pheno predicted more X4-tropic viruses for this set of CRF01_AE sequences than the combined criteria or the 11/25 rule alone. For a conservative approach, Geno2pheno FPR5% seems to be a good compromise to predict CRF01_AE tropism.

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.

Antiretroviral-naive and -treated HIV-1 patients can harbour more resistant viruses in CSF than in plasma

OBJECTIVES

The neurological disorders in HIV-1-infected patients remain prevalent. The HIV-1 resistance in plasma and CSF was compared in patients with neurological disorders in a multicentre study.

METHODS

Blood and CSF samples were collected at time of neurological disorders for 244 patients. The viral loads were >50 copies/mL in both compartments and bulk genotypic tests were realized.

RESULTS

On 244 patients, 89 and 155 were antiretroviral (ARV) naive and ARV treated, respectively. In ARV-naive patients, detection of mutations in CSF and not in plasma were reported for the reverse transcriptase (RT) gene in 2/89 patients (2.2%) and for the protease gene in 1/89 patients (1.1%). In ARV-treated patients, 19/152 (12.5%) patients had HIV-1 mutations only in the CSF for the RT gene and 30/151 (19.8%) for the protease gene. Two mutations appeared statistically more prevalent in the CSF than in plasma: M41L (P=0.0455) and T215Y (P=0.0455).

CONCLUSIONS

In most cases, resistance mutations were present and similar in both studied compartments. However, in 3.4% of ARV-naive and 8.8% of ARV-treated patients, the virus was more resistant in CSF than in plasma. These results support the need for genotypic resistance testing when lumbar puncture is performed.

Prevalence of HIV-1 drug resistance in treated patients with viral load >50 copies/mL in 2009: a French nationwide study

BACKGROUND

Surveillance of HIV-1 drug resistance in treated patients with plasma viral load (VL) >50 copies/mL.

METHODS

The protease and reverse transcriptase (RT) genes were systematically sequenced in samples from 756 patients with VL >50 copies/mL in 2009. The genotyping results were interpreted for each antiretroviral drug (ARV) by using the ANRS algorithm v21. Weighted analyses were used to derive representative estimates of percentages of patients. Prevalence rates were compared with those obtained in 2004 among patients with VL >1000 copies/mL.

RESULTS

Sequences were obtained for 506 patients. Sequencing was successful in 45%, 80% and 96% of samples with VL of 51-500, 501-1000 and >1000 copies/mL, respectively. Resistance or possible resistance to at least one ARV was observed in 59% of samples. Overall, 0.9% of samples contained viruses resistant to all drugs belonging to at least three drug classes. All resistance prevalence rates were significantly lower in 2009 than in 2004.

CONCLUSION

In France, where 86% of patients were receiving combination antiretroviral therapy in 2009, only 15.0% of patients had a VL >50 copies/mL, suggesting that only 8.9% of treated patients could potentially transmit resistant viruses. Only 0.08% of patients harboured viruses fully resistant to at least three antiretroviral drug classes. Further studies are needed to determine whether resistance continues to decline over time.

Increasing prevalence of transmitted drug resistance mutations and non-B subtype circulation in antiretroviral-naive chronically HIV-infected patients from 2001 to 2006/2007 in France

OBJECTIVES

To estimate the prevalence of transmitted drug resistance mutations and non-B subtype circulation in antiretroviral-naive chronically HIV-1-infected patients in France.

METHODS

Resistance mutations were sought in samples from 530 newly diagnosed HIV-1-infected patients from October 2006 to March 2007. Protease and reverse transcriptase mutations were identified from the 2007 Stanford Resistance Surveillance list.

RESULTS

Reverse transcriptase and protease resistance mutations were determined in 466 patients with duration of seropositivity <5 years. 42% of patients were infected with non-B subtype strains (CRF02 18.3%). The overall prevalence of viruses with protease or reverse transcriptase mutations was 10.6% (95% confidence interval 6.7-16.3). The prevalence of protease inhibitor, nucleoside reverse transcriptase inhibitor and non-nucleoside reverse transcriptase inhibitor resistance-associated mutations was 4.7%, 5.8% and 2.8%, respectively. Frequency of resistance was not different in patients infected with B (9.5%) and non-B (CRF02 7.8% and other 11.2%) subtypes. Baseline characteristics such as gender, age, transmission group, country of transmission, disease stage, CD4 counts and viral load were not associated with the prevalence of transmitted drug resistance.

CONCLUSIONS

In France in 2006/2007, the prevalence of transmitted drug-resistant variants was 10.6%. Prevalence of transmitted drug resistance was comparable in B and non-B subtypes. Prevalence of non-B subtypes is still rising.

Variability of the conserved v3 loop tip motif in hiv-1 subtype B isolates collected from brazilian and French patients

The diversity of the V3 loop tip motif sequences of HIV-1 subtype B was analyzed in patients from Botucatu (Brazil) and Montpellier (France). Overall, 37 tetrameric tip motifs were identified, 28 and 17 of them being recognized in Brazilian and French patients, respectively. The GPGR (P) motif was predominant in French but not in Brazilian patients (53.5% vs 31.0%), whereas the GWGR (W) motif was frequent in Brazilian patients (23.0%) and absent in French patients. Three tip motif groups were considered: P, W, and non-P non-W groups. The distribution of HIV-1 isolates into the three groups was significantly different between isolates from Botucatu and from Montpellier (P < 0.001). A higher proportion of CXCR4-using HIV-1 (X4 variants) was observed in the non-P non-W group as compared with the P group (37.5% vs 19.1%), and no X4 variant was identified in the W group (P < 0.001). The higher proportion of X4 variants in the non-P non-W group was essentially observed among the patients from Montpellier, who have been infected with HIV-1 for a longer period of time than those from Botucatu. Among patients from Montpellier, CD4+ cell counts were lower in patients belonging to the non-P non-W group than in those belonging to the P group (24 cells/μL vs 197 cells/μL; P = 0.005). Taken together, the results suggest that variability of the V3 loop tip motif may be related to HIV-1 coreceptor usage and to disease progression. However, as analyzed by a bioinformatic method, the substitution of the V3 loop tip motif of the subtype B consensus sequence with the different tip motifs identified in the present study was not sufficient to induce a change in HIV-1 coreceptor usage.

Comparison of the LCx human immunodeficiency virus (HIV) RNA quantitative, RealTime HIV, and COBAS AmpliPrep-COBAS TaqMan assays for quantitation of HIV type 1 RNA in plasma

The LCx human immunodeficiency virus (HIV) RNA Quantitative, RealTime HIV, and COBAS AmpliPrep-COBAS TaqMan assays for HIV type 1 (HIV-1) were compared for their abilities to quantitate HIV-1 RNA in plasma. High degrees of correlation and agreement were observed between the assays. Differences in HIV-1 RNA levels according to HIV-1 subtypes did not reach statistical significance.

CXCR4 overexpression during the course of HIV-1 infection correlates with the emergence of X4 strains

The factors that determine the emergence of X4 isolates in some HIV-1-infected subjects are unknown. As the level of expression of CXCR4 could favor an R5 to X4 switch, quantitative flow cytometry was used to measure CXCR4 density on CD4 T cells in 200 HIV-1-positive adults, and this was compared with CD4 counts, interleukin-7 (IL-7), and RANTES (regulated on activation, normal T expressed and secreted) plasma levels and the R5/X4 virus phenotype. CD4 T-cell surface CXCR4 densities were increased in infected subjects and inversely correlated with CD4 T-cell count (r=-0.548, P<0.001). Yet, in vitro infection with either R5 or X4 strains and in vivo increases in viral load following interruption of antiretroviral treatment did not induce CXCR4 overexpression. The plasma levels of IL-7 and RANTES, 2 cytokines able to induce CXCR4 expression, did not correlate with CXCR4 density. Finally, higher CXCR4 densities were observed in patients harboring X4 strains (3300, 95% CI 2431-4169 CXCR4 molecules per cell) than in patients harboring only R5 strains (2406, 95% CI 2135-2677, P=0.027). These data suggest that CXCR4 overexpression during the course of the disease in some patients could favor the emergence of X4 strains.

Comparison of Drug Resistance Mutations and Their Interpretation in Patients Infected With Non-B HIV-1 Variants and Matched Patients Infected With HIV-1 Subtype B

OBJECTIVE

To compare the prevalence of mutations associated with resistance to antiretroviral drugs and their interpretation in patients infected with non-B HIV-1 variants versus HIV-1subtype B-infected patients with similar treatment regimens.

METHODS

The reverse transcriptase (RT) and protease genes of HIV-1 were sequenced, and subtypes were determined by phylogenetic analysis. Each sequence belonging to a non-B variant was matched with a sequence belonging to subtype B. Patterns of resistance mutations were interpreted in terms of drug resistance using the HIV db algorithm.

RESULTS

RT mutations M41L, L210W, and, to a lesser extent, T215Y were less prevalent in patients infected with non-B variants. This lower prevalence was associated with subtypes A (A1/A2), C, F (F1/F2), and CRF06_cpx. A lower prevalence of high-level resistance to zidovudine was also observed in patients infected with these HIV-1 variants. In the protease gene, differences between patients infected with B or non-B strains were mainly observed for mutations playing a minor role in drug resistance and known to occur mainly as a natural polymorphism in non-B strains: K20R/M/I, M36I, L63P, A71V/T, and V77I. Interpretation of genotypes using the HIV db algorithm indicated that resistance to saquinavir, ritonavir, indinavir, and amprenavir was more frequently a high-level resistance for subtype B and an intermediate-level resistance for non-B variants, but this difference was only significant for amprenavir.

CONCLUSION

Our results suggest that the genetic diversity of HIV-1 does not play a major role in the development of resistance to antiretroviral drugs.

Prevalence of the mutational pattern E44D/A and/or V118I in the reverse transcriptase (RT) gene of HIV-1 in relation to treatment with nucleoside analogue RT inhibitors

It has been reported that a new pattern of mutations, E44D/A and/or V118I, in the reverse transcriptase (RT) gene of HIV-1 confers a moderate level of resistance to lamivudine in the absence of the M184V mutation. The prevalence of this mutational pattern was studied in HIV-1 isolates obtained from 280 patients. These mutations were not identified in the RT sequences from 23 antiretroviral-naive patients but were detected in 82 (31.9%) of the 257 RT sequences obtained from nucleoside reverse transcriptase inhibitors (NRTI)-experienced patients. Mutation at codon 44 was identified in 41 patients (7 mutations E44A and 34 mutations E44D), mutation V118I was identified in 73 patients and a combination of mutations at codons 44 and 118 was found in 32 patients. Multivariate analysis showed an association between the E44D/A and/or V118I mutational pattern and the RT mutations D67N, T69D, L210W, and T215Y/F. No relationship was observed between this mutational pattern and the lamivudine-specific resistance mutation M184V. The prevalence of these mutations increased significantly with the number of drug regimens experienced and a prevalence of 42.4% was observed in patients who had received >or= 4 antiretroviral regimens. A relationship was found between the E44D/A and/or V118I mutational pattern and experience with didanosine or stavudine but not with lamivudine. The results suggest that the development of the E44D/A and/or V118I mutational pattern is frequent in patients treated with NRTIs. Thymidine analogues and didanosine, but not lamivudine, could promote the development of these mutations.

Patterns of resistance mutations to antiretroviral drugs in extensively treated HIV-1-infected patients with failure of highly active antiretroviral therapy

Resistance-mutation patterns in the reverse transcriptase (RT) and protease genes of HIV-1 were analyzed in 22 patients who had been extensively pretreated and who failed to respond to highly active antiretroviral therapy (HAART). The number of mutations ranged from 8 to 19 (median, 13): 4 to 12 (median, 6) mutations in the RT gene, and 4 to 8 (median, 7) mutations in the protease gene. In the RT gene, the most frequent resistance mutations were found at codons 215 (100%), 41 (95%), 67 (91%), and 210 (77%). Multidrug-resistant mutation patterns including Q151M and insertion mutations at codon 69, which confer cross-resistance to the different nucleoside analogue RT inhibitors were detected in 1 and 3 patients, respectively; 1 patient with insertion mutation displayed a NGQGV [corrected] sequence at codons 67 to 70. In the protease gene, the most frequent mutations were found at codons 63 (95%), 10 (86%), 90(86%), 71(77%), 46 (50%), 36 (45%), and 84 (45%). Genotypic resistance to zidovudine, saquinavir, and indinavir was found in 100% of the patients. All patients showed also resistance or possible resistance to stavudine, abacavir, ritonavir, and nelfinavir. Mutations conferring genotypic resistance to nonnucleoside analogue RT inhibitors (NNRTIs) were found in 12 (80%) of the NNRTI-experienced patients and 1 of 7 NNRTI-naive patients. Our results indicate that failure of HAART in the patients extensively pretreated results from the multiplicity of RT and protease mutations that confer genotypic resistance to almost all available antiretroviral drugs. In these patients, genotypic resistance tests confirm the lack of alternative salvage therapy strategies based on the currently available antiretroviral drugs.

Emergence of zidovudine and multidrug-resistance mutations in the HIV-1 reverse transcriptase gene in therapy-naive patients receiving stavudine plus didanosine combination therapy. STADI Group

OBJECTIVE

Assessment of genotypic changes in the reverse transcriptase gene of HIV-1 occurring in antiretroviral naive patients treated by stavudine plus didanosine combination therapy.

METHODS

Sequence analysis (codons 1-230) was performed after amplification of the reverse transcriptase gene from plasma samples collected at baseline and at the end of treatment from 39 previously treatment-naive patients treated for 24-48 weeks.

RESULTS

At baseline, mutations associated with zidovudine resistance were detected in plasma from two patients: Asp67Asn/Lys219Gln and Leu210Trp. Among the 39 subjects, 18 (46%) developed mutations: one developed the Val75Thr/Ala mutation, four (10%) developed a Gln151Met multidrug-resistance mutation (MDR), associated in one of them with the Phe77Leu and the Phe116Tyr MDR mutations and 14 (36%) developed one or more zidovudine-specific mutations (Met41Leu, Asp67Asn, Lys70Arg, Leu210Trp, Thr215Tyr/Phe). The development of a Met41Leu zidovudine-specific mutation was associated with the development of a Gln151Met mutation in one patient. Other reverse transcriptase mutations known to confer resistance to nucleoside analogues were not detected. At inclusion, there was no statistical difference in HIV-1 load between patients who developed resistance mutations and those who did not. RNA HIV-1 load decrease was higher (P = 0.05) in patients who maintained a wild-type reverse transcriptase genotype (-2.22 log10 copies/ml) than in patients who developed resistance mutations (-1.14 log10 copies/ml).

CONCLUSION

Stavudine/didanosine combination therapy is associated with emergence of zidovudine-related resistance or MDR mutations in naive patients. These findings should be considered when optimizing salvage therapy for patients who have received a treatment including stavudine/didanosine combination.

Comparison of the QUANTIPLEX HIV-1 RNA 2.0 assay with the AMPLICOR HIV-1 MONITOR 1.0 assay for quantitation of levels of human immunodeficiency virus type 1 RNA in plasma of patients receiving stavudine-didanosine combination therapy

We compared the QUANTIPLEX HIV-1 RNA 2.0 assay with the AMPLICOR HIV-1 MONITOR 1.0 assay for quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in plasma in the Stadi trail, which evaluated a stavudine plus didanosine combination therapy in 52 patients. HIV-1 RNA baseline values measured with AMPLICOR HIV-1 MONITOR 1.0 were significantly higher than those measured with QUANTIPLEX HIV-1 RNA 2.0, and decreases in HIV-1 RNA levels from baseline were also found to be significantly higher when measured with the AMPLICOR HIV-1 MONITOR 1.0 assay. The frequency of HIV-1 RNA levels below the lower limit of quantitation was significantly higher with QUANTIPLEX HIV-1 RNA 2.0 than with AMPLICOR HIV-1 MONITOR 1.0. Reanalysis of these results by an ultrasensitive procedure of AMPLICOR HIV-1 MONITOR 1.0 or by a modified version of the test that included additional primers adapted for non-B HIV-1 clades yielded greater differences between the QUANTIPLEX HIV-1 RNA 2.0 assay and the AMPLICOR HIV-1 MONITOR 1.0 assay. Our results indicate that a valid comparison of the virological efficacies obtained with different antiretroviral drug regimens requires the use of the same viral load quantitation procedure; further standardization between the different HIV-1 RNA quantitation kits is therefore needed.

Evaluation of the Nuclisens HIV-1 QT assay for quantitation of human immunodeficiency virus type 1 RNA levels in plasma

Nuclisens HIV-1 QT is a new version of the NASBA HIV-1 QT assay for quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in plasma. The specificity of this assay was 100% in one laboratory and 99%-with nonrepeatability of the initial false positive-in another. The test was linear between 2.0 and 6.0 log RNA copies per ml. According to the input HIV-1 RNA concentration, accuracy varied from -0.11 to +0.10 log RNA copy per ml and precision varied from 0.66 to 0.14 log RNA copy per ml. Reproducibility decreased when the HIV-1 RNA level was near the lower limit of quantitation of the test. HIV-1 RNA could be quantitated by Nuclisens HIV-1 QT in 36% (laboratory 1) and 24% (laboratory 2) of clinical samples with HIV-1 RNA levels lower than the lower limit of quantitation by NASBA HIV-1 QT. Nuclisens HIV-1 QT was not suitable for measurement of RNA from clade G and group O HIV-1 strains.

[Once-daily administration of didanosine in combination with anti-retroviral zidovudine in previously untreated patients]

25 HIV-infected antiretroviral-naive adults were included in a 24-week study to evaluate the efficacy and the tolerability of a zidovudine/didanosine combination therapy in which didanosine was administered once daily (200 mg if weight < 60 kg, 300 mg if weight > 60 kg) and zidovudine twice daily (500 mg/day if weight < 90 kg, 600 mg/day if weight > 90 kg). 5 patients discontinued their treatment early: 3 had poor compliance and 2 presented adverse events. Evaluation of treatment efficacy was based on CD4+ T cell enumeration and HIV RNA level quantitation in plasma (NASBA). Baseline values were 278 CD4+/mm3 and 5.42 log RNA copies/ml. Mean changes from baseline were +102 CD4+/mm3 and -2.14 log RNA copies/ml at week 8 and +156 CD4+/mm3 and -2.07 log RNA copies/ml at week 24. HIV RNA in plasma was lower than the detection limit (2.60 log RNA copies/ml) in 55% of patients at week 8 and in 30% at week 24. No major adverse events such as neuropathy or pancreatitis were observed. Once-daily administration of didanosine in combination with twice-daily administration of zidovudine is a well tolerated regimen that appears to be as effective ad the conventional zidovudine/didanosine combination regimen.

Comparative evaluation of three assays for the quantitation of human immunodeficiency virus type 1 RNA in plasma

Reverse transcriptase-coupled polymerase chain reaction (Amplicor HIV-1 Monitor), the branched DNA (bDNA) method (Quantiplex HIV-1 RNA) and the nucleic acid sequence-based assay (NASBA HIV-1 RNA QT) were comparatively evaluated for the quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in plasma. Among 60 plasma specimens from HIV-1 infected patients, HIV-1 RNA was detected in 56 by Amplicor (sensitivity, 93.3%), in 41 by bDNA (sensitivity, 68.3%), and in 60 by NASBA (sensitivity, 100%). HIV-1 RNA was not detected by any of these methods in 34/34 plasma specimens from HIV-1-seronegative blood donors (specificity, 100%). The HIV-1 RNA levels as determined by the different methods were correlated significantly. The frequency of concordant results (log difference < 0.50) was 80.4% between Amplicor and NASBA, 77.5% between Amplicor and bDNA, and 58.6% between bDNA and NASBA. After initiation of antiviral therapy, HIV-1 RNA level variations observed with the three methods were similar. HIV-1 RNA levels were inversely correlated with the CD4+ T cell counts, whereas no correlation was found with HIV-1 p24-antigen levels. When the methods were evaluated for reproducibility, coefficients of variation ranged from 11% to 40% for Amplicor, from 6% to 35% for bDNA, and from 13% to 62% for NASBA. Quantitation of HIV-1 RNA in culture supernatants from HIV-1 subtype A to H strains showed that bDNA can be used to quantitate RNA from all HIV-1 subtypes, whereas Amplicor failed to detect RNA from subtype A strains and NASBA subtype G strains.

Significance of cytomegalovirus (CMV)-pp65 antigenemia in the diagnosis of CMV disease in human immunodeficiency virus-infected patients

To establish the diagnostic value of the cytomegalovirus (CMV)-pp65 antigenemia in CMV disease occurring in human immunodeficiency (HIV)-infected patients, CMV-pp65 antigen in polymorphonuclear leukocytes (PMNLs) was assayed in 373 samples from 138 randomly included patients followed up for symptomatic HIV-1 infection and the correlation between CMV-pp65 antigenemia and diagnosis of CMV disease was investigated. Thirty-seven CMV disease episodes were observed in 30 patients and 89.2% of these episodes were associated with a positive CMV-pp65 antigenemia. In contrast, 94% of the patients negative for CMV-pp65 antigenemia remained free of CMV disease. Patients with CMV disease had significantly higher levels of CMV-pp65 antigenemia than CMV disease-free patients (695 positive cells/2 x 10(5) PMNLs vs. 28 positive cells/2 x 10(5) PMNLs). The positive and negative predictive values of the test were 45% and 94%, respectively, but were 93% and 80%, respectively, when a CMV-pp65 antigenemia level of > 100 positive cells/2 x 10(5) PMNLs was taken into consideration. These results indicate that the CMV-pp65 antigenemia assay is useful for the diagnosis and monitoring of CMV disease in HIV-infected patients.

Single dose pharmacokinetics of fenspiride hydrochloride: phase I clinical trial

The absolute bioavailability of fenspiride has been studied in twelve healthy volunteers. It was administered IV and orally in single doses of 80 mg fenspiride hydrochloride according to a randomised crossover pattern. Following IV administration, the plasma clearance of fenspiride was about 184 ml.min-1, and its apparent volume of distribution was moderately large (215 l). When given orally as a tablet, fenspiride exhibited fairly slow ab- sorption; the maximum plasma concentration (206 ng.ml-1) was achieved 6 h after administration. The absolute bioavailability was almost complete (90%). The tablet had slow release characteristics. The elimination half-life obtained from the plasma data was 14 to 16 h independent of the route of administration.

[Comparative bioavailability and pharmacokinetics of Dolotren retard and Dolotren]

A randomized crossover study was designed in order to evaluate the bioequivalence of a sustained-release preparation (DR) of diclofenac sodium (Dolotrén RETARD) with respect to an enteric coated (D) tablet (Dolotren). For this purpose the bioavailability of both formulations, orally administered in single and multiple doses, was determined. Nine healthy volunteers were included in this study, receiving 100 mg of D and 100 mg of DR, firstly in single dose and then for 15 days b.i.d. for D group and once a day for DR group. For the analytical determination of diclofenac, blood samples at established time intervals, the day of the single dose and the 3rd, 7th and 15th day of multiple dose administration, were taken. The following kinetic parameters were determined: Cmac, tmax, alpha and beta, clearance, ka, area under the curve and absolute and relative bioavailability. When administered both endovenous and orally, the great interindividual variability in the kinetic characteristics of diclofenac sodium is evidenced. The lag time (tlag) for DR is 0.4 h, shorter than for D (2.2 h), which indicates a faster absorption in the upper sections of the gastrointestinal tract. Also tmax was shorter for Dr (1.9 h) than for D (4.3 h). Cmax obtained with D was higher tan with DR. The diclofenac sodium elimination process from plasma is significantly slower with DR than with D (t1/2 beta = 18.1 h and 2.5 h, respectively). In consequence, quantifiable plasmatic levels are maintained for at least 24 hours after administration of DR, but not of D. Absolute bioavailability of both preparations is about 80%, with great interindividual variations. Significant differences between the two preparations could not be demonstrated. Relative bioavailability between DR and D was 91.5%. None of the preparations when administered in repeated doses, D every 12 hours and DR every 24 hours, produced accumulation, neither their pharmacokinetic characteristics changed. Clinical and biological tolerance of both preparations were excellent, at doses used and for the period of time studied. Dolotren Retard is absorbed orally faster than Dolotren and maintains plasmatic levels longer, which allows it to be administered once a day, with a lesser incidence of undesirable effects related to Cmax.

[In vitro effect of itraconazole against various species of Candida]

The authors compared the in vitro antifungal activity of itraconazole to that of miconazole against various species of Candida. The MIC of 88 strains of Candida (C. albicans, C. guilliermondii, C. parapsilosis, C. glabrata) was determined by the agar dilution method using casitone medium at pH 5.5-5.6 for miconazole and pH 7.2-7.4 for itraconazole. C. albicans and C. glabrata were found to be less sensitive in vitro to itraconazole than to miconazole; the contrary was observed for C. parapsilosis. The sensitivity of C. guilliermondii to these antifungal agents was similar. The MIC 50, MIC 90 and G.MIC values for itraconazole with respect to 42 strains of C. albicans was 0.10, 1.4 and 0.138 micrograms ml-1, respectively; the MIC 90 and G.MIC values for miconazole were 0.5 and 0.021 micrograms ml-1, respectively. The effect of itraconazole on the ultrastructure of C. albicans yeast cells and spheroplasts was studied by scanning electron microscopy. This triazole molecule modified the cell wall of C. albicans, caused cell stretching and provoked defective separation between mother and daughter cells. Itraconazole altered the cytoplasmic membrane of the spheroplasts causing them to have a "spongy" appearance. Yeast cells treated with itraconazole appeared to liberate their spheroplast with difficulty.

[Comparative action of 8 azole derivatives against Candida albicans: fungistatic action and cytologic study by scanning electron microscopy]

The authors compared the in vitro antifungal activity of eight imidazole derivatives (clotrimazole, econazole, isoconazole, ketoconazole, miconazole, oxiconazole, terconazole, tioconazole) against 42 strains of Candida albicans by the agar dilution method using casitone medium. The geometric (G) mean MIC values, the MIC 90 and the MIC 50 values and the corresponding standard deviations of each antifungal agent were determined. The G-MIC values were found to be in the range of 0.008-0.390 micrograms ml-1. The effects of these eight antifungal agents on the ultrastructure of C. albicans yeast cells and spheroplasts were studied by scanning electron microscopy (SEM). The results showed a good correlation between the lesions observed and the structure of the imidazole derivatives tested. On the basis of the SEM results, the compounds could be divided into three groups: (1) ketoconazole and terconazole; (2) econazole, isoconazole, miconazole, oxiconazole and tioconazole; (3) clotrimazole.