Simona Di Giambenedetto

Usefulness of monitoring HIV drug resistance and adherence in individuals failing highly active antiretroviral therapy: a randomized study (ARGENTA).

Objective To establish the influence of genotypic resistance-guided treatment decisions and patient-reported adherence on the virological and immunological responses in patients failing a potent antiretroviral regimen in a randomized, controlled trial in a tertiary care infectious diseases department. Patients A total of 174 patients with virological failure were randomly assigned to receive standard of care (SOC) or additional genotypic resistance information (G). Adherence was measured by a self-administered questionnaire. Main outcomes measures Primary endpoints were the proportion with HIV-RNA < 500 copies/ml at 3 and 6 months by intention-to-treat analysis. Secondary endpoints were changes from baseline HIV-RNA levels and CD4 cell counts. Results At entry, 25% had failed three or more highly active antiretroviral therapy (HAART) regimens and 41% three drug classes; there were more resistance mutations in G. In 127 evaluable questionnaires, 43% reported last missed dose during the previous week. At 3 months, 11 of 89 patients (12%) in SOC and 23 of 85 (27%) in G had HIV-RNA < 500 copies/ml (OR 2.63, 95% CI 1.12–6.26); the relative proportions were 17 and 21% at 6 months. CD4 cell changes did not differ between arms. Six month CD4 cell changes were +62 in adherent and −13 cells/μl in non-adherent patients (P < 0.01). Being assigned to G, good adherence, previous history of virological success, fewer experienced HAART regimens and lower baseline viral load were independently predictive of 3 month virological success. Conclusion The virological benefit of genotype-guided treatment decisions in heavily pre-exposed patients was short term. Patients adherence and residual treatment options influenced outcomes.

Cross-Resistance among Nonnucleoside Reverse Transcriptase Inhibitors Limits Recycling Efavirenz after Nevirapine Failure

Heterogeneity in genotype mutations associated with resistance of HIV to nonnucleoside reverse transcriptase inhibitors (NNRTIs) should allow identification of patients failing nevirapine (NVP) who might benefit from efavirenz (EFV)-containing salvage regimens. To establish the feasibility of recycling EFV after failure of NVP-containing regimens genotypic data on 103 NVP-failed patients were analyzed to evaluate the prevalence of EFV resistance-conferring mutations. A clinically significant resistance to EFV was found in 50 of 103 (58%) of NVP-failed subjects. Furthermore, the 3-month virological response to salvage regimens containing EFV was assessed in patients previously treated with NVP and carrying single mutations conferring resistance to this drug. A proportion of HIV RNA less than 500 copies/ml at 3 months was obtained only in 2 of 12 (17%) of EFV-treated subjects compared with 35 of 67 (52%) of those without NNRTI mutations (OR, 0.18; 95% CI, 0.03-0.79). The median HIV-1 RNA decrease after 3 months was -0.63 log(10) among patients carrying single NNRTI-associated mutations compared with -1.32 log(10) among those without any NNRTI mutations. No virological response was observed in six patients harboring a single Y181C/I mutation. On the basis of the present data, sequential use of NNRTIs should be avoided in the management of treatment failure.

Cidofovir in addition to antiretroviral treatment is not effective for AIDS-associated progressive multifocal leukoencephalopathy: a multicohort analysis

Objective:To establish the effectiveness of cidofovir for AIDS-related progressive multifocal leukoencephalopathy (PML) in patients concomitantly receiving combination antiretroviral therapy. Design:Analysis of raw data pooled from one prospective and five cohort studies. Setting:Tertiary care centers for the treatment of HIV-associated complications. Patients:Three hundred seventy HIV-infected PML patients diagnosed from 1996 treated with combination antiretroviral therapy with or without cidofovir. All studies had already published their results but for four of them, additional patients and follow-up data are included in this report. Follow-up was started from the date of first abnormal neuroimaging; those treated with cidofovir were entered at risk at the date of cidofovir initiation.Main study outcomes were time to PML-related death and odds of 12-month moderately severe to severe disability (Rankin score ≥4). Results:Sixty-four percent of the PML cases were confirmed by histopathology or JC virus DNA detection in cerebrospinal fluid; 185 (50%) received cidofovir (median five cycles). During 463 person-years of follow-up, 167 PML-related deaths occurred (36.6 per 100 person-years of follow-up). Estimated 1 year survival was 0.56 (95% confidence interval, 0.50–0.61). In multivariate models stratified by cohort and adjusted for type of diagnosis and relevant prognostic confounders, cidofovir treatment was not associated with survival (hazard ratio for death 0.93, 0.66–1.32). Results were similar using time to death from any cause as the outcome. Furthermore, 12-month moderately severe to severe disability was not associated with the use of cidofovir. Conclusion:In combination antiretroviral therapy-treated PML patients, cidofovir use did not influence PML-related mortality or residual disability. New treatments for AIDS-related PML are urgently needed.

Reduced Rate of Diagnostic Positive Detection of JC Virus DNA in Cerebrospinal Fluid in Cases of Suspected Progressive Multifocal Leukoencephalopathy in the Era of Potent Antiretroviral Therapy

ABSTRACT Fifty-nine human immunodeficiency virus (HIV)-infected patients with suspected progressive multifocal leukoencephalopathy and 224 controls were tested for JC virus (JCV) DNA in cerebrospinal fluid by PCR. The diagnostic positive detection rate dropped from 89.5% (95% confidence intervals of 75.5 to 103.5%) in the pre-highly active antiretroviral therapy (HAART) era to 57.5% (95% confidence intervals of 42.1 to 72.9%) in the HAART era; the specificity remained unchanged. Predictors of failure to detect JCV DNA were exposure to HAART at disease onset and higher CD4 counts.

Antiretroviral therapy optimisation without genotype resistance testing: a perspective on treatment history based models

Background Although genotypic resistance testing (GRT) is recommended to guide combination antiretroviral therapy (cART), funding and/or facilities to perform GRT may not be available in low to middle income countries. Since treatment history (TH) impacts response to subsequent therapy, we investigated a set of statistical learning models to optimise cART in the absence of GRT information. Methods and Findings The EuResist database was used to extract 8-week and 24-week treatment change episodes (TCE) with GRT and additional clinical, demographic and TH information. Random Forest (RF) classification was used to predict 8- and 24-week success, defined as undetectable HIV-1 RNA, comparing nested models including (i) GRT+TH and (ii) TH without GRT, using multiple cross-validation and area under the receiver operating characteristic curve (AUC). Virological success was achieved in 68.2% and 68.0% of TCE at 8- and 24-weeks (n = 2,831 and 2,579), respectively. RF (i) and (ii) showed comparable performances, with an average (st.dev.) AUC 0.77 (0.031) vs. 0.757 (0.035) at 8-weeks, 0.834 (0.027) vs. 0.821 (0.025) at 24-weeks. Sensitivity analyses, carried out on a data subset that included antiretroviral regimens commonly used in low to middle income countries, confirmed our findings. Training on subtype B and validation on non-B isolates resulted in a decline of performance for models (i) and (ii). Conclusions Treatment history-based RF prediction models are comparable to GRT-based for classification of virological outcome. These results may be relevant for therapy optimisation in areas where availability of GRT is limited. Further investigations are required in order to account for different demographics, subtypes and different therapy switching strategies.

Variable Prediction of Antiretroviral Treatment Outcome by Different Systems for Interpreting Genotypic Human Immunodeficiency Virus Type 1 Drug Resistance

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

Pharmacokinetic variability of antiretroviral drugs and correlation with virological outcome: 2 years of experience in routine clinical practice

OBJECTIVES To assess the inter-individual and intra-individual plasma concentration variabilities of non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs) in routine clinical practice and to investigate their relationships with virological failure. METHODS We retrospectively enrolled HIV-infected patients undergoing therapeutic drug monitoring (TDM) of NNRTIs and PIs during routine outpatient visits. Plasma drug concentrations were measured by HPLC-UV and were considered therapeutic if above the proposed minimum efficacy trough concentration. Inter-individual and intra-individual variabilities were evaluated through the coefficient of variation (CV). RESULTS A total of 457 PI and 172 NNRTI plasma concentrations were measured from 363 patients (HIV-RNA <50 copies/mL in 70.8%, median CD4 count 434 cells/mm(3)). NNRTIs showed less inter-individual (CV(inter) 54.8% versus 84.3%) and intra-individual (CV(intra) 19.0% versus 38.1%) pharmacokinetic variabilities than PIs. Intra-individual variability was constantly lower than inter-individual variability for each drug. Subtherapeutic drug concentrations were observed in 106 samples (16.9%). Older age (P = 0.020) and higher viral load (P = 0.013) were associated with subtherapeutic levels. Patients with therapeutic levels had a viral load of <50 copies/mL more frequently than those with subtherapeutic levels (74.8% versus 63.2%, P = 0.020). The estimated proportion with virological failure at 24 weeks was 0.21 in patients with suboptimal baseline drug levels and 0.08 in those with optimal levels (P < 0.001). In the multivariate analysis, therapeutic drug levels showed an independent negative association with virological failure (P = 0.004). CONCLUSIONS A wide inter-individual and limited intra-individual pharmacokinetic variabilities, together with the demonstration of a concentration-response relationship, suggest that TDM is a useful tool for the clinical management of patients treated with NNRTIs or PIs.

Female sex and the use of anti-allergic agents increase the risk of developing cutaneous rash associated with nevirapine therapy

To identify factors associated with cutaneous rash, we performed a retrospective multicentre analysis of HIV outpatients starting a highly active antiretroviral therapy regimen containing nevirapine. A total of 62 cutaneous adverse events were observed in 429 patients. Rash hazard was increased in women, by the prophylactic use of glucocorticoids or antihistaminics, and was reduced by escalating the initial dose of nevirapine. Women receiving glucocorticoids had a 3 month cumulative probability of rash of 0.41.

Is the virulence of HIV changing? A meta-analysis of trends in prognostic markers of HIV disease progression and transmission

Objective:The potential for changing HIV-1 virulence has significant implications for the AIDS epidemic, including changing HIV transmission rates, rapidity of disease progression, and timing of ART. Published data to date have provided conflicting results. Design:We conducted a meta-analysis of changes in baseline CD4+ T-cell counts and set point plasma viral RNA load over time in order to establish whether summary trends are consistent with changing HIV-1 virulence. Methods:We searched PubMed for studies of trends in HIV-1 prognostic markers of disease progression and supplemented findings with publications referenced in epidemiological or virulence studies. We identified 12 studies of trends in baseline CD4+ T-cell counts (21 052 total individuals), and eight studies of trends in set point viral loads (10 785 total individuals), spanning the years 1984–2010. Using random-effects meta-analysis, we estimated summary effect sizes for trends in HIV-1 plasma viral loads and CD4+ T-cell counts. Results:Baseline CD4+ T-cell counts showed a summary trend of decreasing cell counts [effect = −4.93 cells/&mgr;l per year, 95% confidence interval (CI) −6.53 to −3.3]. Set point viral loads showed a summary trend of increasing plasma viral RNA loads (effect = 0.013 log10 copies/ml per year, 95% CI −0.001 to 0.03). The trend rates decelerated in recent years for both prognostic markers. Conclusion:Our results are consistent with increased virulence of HIV-1 over the course of the epidemic. Extrapolating over the 30 years since the first description of AIDS, this represents a CD4+ T cells loss of approximately 148 cells/&mgr;l and a gain of 0.39 log10 copies/ml of viral RNA measured during early infection. These effect sizes would predict increasing rates of disease progression, and need for ART as well as increasing transmission risk.

Comparative determination of HIV-1 co-receptor tropism by Enhanced Sensitivity Trofile, gp120 V3-loop RNA and DNA genotyping

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