Epidemiology of transmitted drug resistance in chronically HIV-infected patients in Germany: the RESINA study 2001-2009

Checklist for studies of HIV drug resistance prevalence or incidence: rationale and recommended use

HIV drug resistance (HIVDR) is a major challenge to the effectiveness of antiretroviral therapy. Global efforts in addressing HIVDR require clear, transparent, and replicable reporting in HIVDR studies. We describe the rationale and recommended use of a checklist that should be included in reports of HIVDR incidence and prevalence. After preliminary consultations with experts on HIVDR and establishing the need for guidance on HIVDR reporting, we used a sequential, explanatory, mixed methods approach to create the checklist; together with the accompanying articles, the checklist was reviewed by the authors and validated externally. The checklist for studies on HIVDR prevalence or incidence (CEDRIC-HIV) includes 15 recommended items that would enhance transparency and facilitate interpretation, comparability, and replicability of HIVDR studies. CEDRIC-HIV will help authors of HIVDR studies prepare research reports and assist reviewers and editors in assessments of completeness of reporting. The checklist will also facilitate statistical pooling and interpretation of HIVDR data.

Torque Teno Virus plasma level as novel biomarker of retained immunocompetence in HIV-infected patients

PURPOSE

To predict the course of immune recovery (IR) in HIV-1-infected patients after initiation of combined antiretroviral therapy (cART) by determination of the plasma concentration of Torque Teno Virus (TTV). TTV has been identified as marker for risk assessment in immunosuppressed patients after transplantation procedures. Here, TTV was analyzed in HIV-1-infected therapy-naïve patients to evaluate its use as predictor of the course of IR for guidance of individualized treatment.

METHODS

TTV DNA was quantified in plasma samples of 301 therapy-naïve HIV-1-infected patients and correlated to CD4⁺ cell count, HIV viral load, presence of the herpes viruses CMV, EBV and HHV-8, age and sex. Patients were classified according to their initial CD4⁺ cell count and to the extent of CD4⁺ T-cell increase within the first year of cART.

RESULTS

TTV DNA was detectable in 96% of the patients' plasma samples with a median TTV plasma concentration of 5.37 log₁₀ cop/ml. The baseline CD4⁺ cell count was negatively correlated with TTV plasma concentration (p = 0.003). In patients with a CD4⁺ cell recovery < 50 cells/µl, the median TTV plasma concentration was significantly higher compared to patients with a CD4⁺ cell recovery of > 200 CD4⁺ cells/µl (5.68 log₁₀ cop/ml versus 4.99 log₁₀ cop/ml; p = 0.011). TTV plasma concentration in combination with baseline CD4⁺ cell count were significantly correlated to CD4⁺ cell recovery (p = 0.004). For all other parameters considered, no significant correlation for CD4⁺ cell recovery was found.

CONCLUSION

Within the cohort, the significantly elevated TTV plasma concentration in patients with diminished CD4⁺ cell recovery indicates a more profound immune defect. Baseline TTV plasma concentrations and CD4⁺ cell count are predictive for the course of immune recovery in HIV-1-infected patients with severe immunodeficiency.

[HIV infection : Test and treatment]

In Europe depending on the country 15-80 % of all individuals infected with human immunodeficiency virus (HIV) are either not aware of the diagnosis or are diagnosed later. An early HIV diagnosis could, however, considerably improve the prognosis of individuals infected with HIV and decrease the risk of new infections; therefore, in the presence of indicator diseases, such as sexually transmitted diseases, oral thrush, herpes zoster and lymphoma, the performance of a HIV test is of utmost importance. A newly diagnosed HIV infection represents an indication for starting antiretroviral combination therapy independent of the clinical stage or CD4 cell count. A decline of the viral burden to below the limit of detection and subsequent continuous suppression of viral replication can prevent transition from HIV to acquired immune deficiency syndrome (AIDS) and if started early enough a normal life expectancy can be achieved. Challenges which remain in HIV therapy are the lifelong daily intake of medication and the complex long-term adverse effects.

HIV-1 Subtype Diversity and Prevalence of Primary Drug Resistance in a Single-Center Pediatric Cohort in Germany

OBJECTIVES

Data on drug-resistant mutations (DRMs) in HIV-1-infected therapy-naïve children are scarce. The aim of this study was to determine the HIV-1 subtype distribution and the prevalence of DRMs in therapy-naïve HIV-1-infected children who received routine care at the University Hospital Düsseldorf, Düsseldorf, Germany.

METHODS

Records of all HIV-1-infected children who received routine care between January 2005 and December 2015 were analyzed retrospectively. The collected data included demographics, clinical characteristics, CD4 cell count, viral load, HIV-1 subtype, and resistance genotype at baseline.

RESULTS

83 HIV-1-infected children received routine care during the observation period. HIV-1 subtypes were available in 61/83 patients (73.5%) and baseline HIV-1 resistance in 24 (29%). The prevalence of major DRMs was 29% (21% nucleoside reverse-transcriptase inhibitors [NRTIs], 12.5% non-NRTIs, and 4% protease inhibitors). Minor mutations in the protease gene were common (58%). Non-B subtypes were predominant (77%).

CONCLUSIONS

We report a predominance of non-subtype-B infections and a higher prevalence of DRMs compared to other pediatric cohorts from resource-rich settings. The difference in HIV-1 subtype distribution is due to the fact that a relevant proportion of pediatric patients in Germany are immigrants from high-prevalence settings in sub-Saharan Africa where non-B subtypes predominate.

Novel tetra-peptide insertion in Gag-p6 ALIX-binding motif in HIV-1 subtype C associated with protease inhibitor failure in Indian patients

A novel tetra-peptide insertion was identified in Gag-p6 ALIX-binding region, which appeared in protease inhibitor failure Indian HIV-1C sequences (odds ratio=17.1, P < 0.001) but was naturally present in half of untreated Ethiopian HIV-1C sequences. The insertion is predicted to restore ALIX-mediated virus release pathway, which is lacking in HIV-1C. The clinical importance of the insertion needs to be evaluated in HIV-1C dominating regions wherein the use of protease inhibitor drugs are being scaled up.

Ten years survey of primary HIV-1 resistance in Serbia: the occurrence of multiclass resistance

In Serbia, the first cases of HIV infection were reported in 1985, whereas antiretroviral (ARV) therapy has been in use since 1987. With this study we aimed to assess the occurrence and pattern of HIV resistance mutations among newly diagnosed patients in the period 2002-2011. The study prospectively included 181 adult patients. Genotypic HIV-1 drug resistance testing was performed and drug resistance was scored according to the 2009 WHO list for surveillance of drug resistance mutations (SDRMs). A bioinformatic approach was used to estimate the duration of infection by calculating the percentage of ambiguous basecalls per sequence, with a cutoff of 0.47% as the delimiter for recent infection. The overall prevalence of transmitted drug resistance (TDR) found in the study was 8.8% (16/181, 95% CI=5.5-13.8). Thirty-one percent of resistant samples contained multiple SDRMs. In particular, 5/16 patients with resistance carried viral strains with SDRMs to multiple ARV classes, hence one-third of resistant strains were multiclass resistant, including non-B strains. A total of 51.9% of samples (94/181) were classified as recent infection, with a significant increase in the second part of the study period. However, the prevalence of TDR in recent infection was 6.4% (6/94, 95% CI=2.9-13.2), not statistically different from that found in nonrecent infection. We showed a changing pattern of TDR mutations over the study period, with a substantial occurrence of multiclass resistance, across different HIV subtypes. Our results highlight the need for continued surveillance of primary resistance.

Ambulatory care for HIV-infected patients: differences in outcomes between hospital-based units and private practices: analysis of the RESINA cohort

Background

The efficacy of highly active antiretroviral therapy (HAART) in the treatment of HIV infection is influenced by factors such as potency of applied drugs, adherence of the patient, and resistance-associated mutations. Up to now, there is insufficient data on the impact of the therapeutic setting.

Methods

Since 2001, the prospective multicenter RESINA study has examined the epidemiology of transmitted HIV drug resistance in Nordrhein-Westfalen, the largest federal state of Germany by population. Characteristics of patients treated in hospital-based outpatient units were compared to those of patients treated in medical practices. Longitudinal data of all participants are being followed in a cohort study.

Results

Overall, 1,591 patients were enrolled between 2001 and 2009 with follow-up until the end of 2010. Of these, 1,099 cases were treated in hospital-based units and 492 in private practices. Significant differences were found with respect to baseline characteristics. A higher rate of patients with advanced disease and non-European nationality were cared for in hospital units. Patients in medical practices were predominantly Caucasian men who have sex with men (MSM) harboring HIV-1 subtype B, with lower CDC stage and higher CD4 cell count. Median viral load was 68,828 c/mL in hospital-based units and 100,000 c/mL in private practices (P = 0.041). Only median age and rate of transmitted drug resistance were not significantly different. After 48 weeks, 81.9% of patients in hospital units and 85.9% in private practices had a viral load below the limit of detection (P = 0.12). A similar result was seen after 96 weeks (P = 0.54). Although the baseline CD4 cell count was different (189.5/μL in hospital units and 246.5/μL in private practices, P <0.001), a consistent and almost identical increase was determined in both groups.

Conclusions

The RESINA study covers a large HIV-infected patient cohort cared for in specialized facilities in Germany. Despite significant differences of patients’ baseline characteristics in hospital-based units compared to medical practices, we could not find significant differences in treatment outcome up to 2 years after the initiation of HAART.

The prevalence of transmitted resistance to first-generation non-nucleoside reverse transcriptase inhibitors and its potential economic impact in HIV-infected patients

Non-nucleoside reverse transcriptase inhibitor (NNRTI)-based highly active antiretroviral therapy (HAART) including efavirenz is recommended as a 1^st-line treatment choice in international HIV guidelines, and it is one of the most common components of initial therapy. Resistance to 1^st-generation NNRTIs is found among treated and untreated HIV-infected individuals creating a subpopulation of HIV-infected individuals in whom efavirenz is not fully effective. This analysis reviewed published articles and conference abstracts to examine the prevalence of 1^st-generation NNRTI resistance in Europe, the United States (US), and Canada and to identify published evidence of the economic consequences of resistance. The reported prevalence of NNRTI resistance was generally higher in US/Canada than in Europe and increased in both regions from their introduction in the late 1990s until the early 2000s. The most recent time-based trends suggest that NNRTI-resistance prevalence may be stable or decreasing. These estimates of resistance may be understated as resistance estimates using ultra-sensitive genotypic testing methods, which identify low-frequency mutations undetected by standard testing methods, showed increased prevalence of resistance by more than two-fold. No studies were identified that explicitly investigated the costs of drug resistance. Rather, most studies reported costs of treatment change, failure, or disease progression. Among those studies, annual HIV medical costs of those infected with HIV increased 1) as CD4 cells decreased, driven in part by hospitalization at lower CD4 cell counts; 2) for treatment changes, and 3) for each virologic failure. The possible erosion of efficacy or of therapy choices through resistance transmission or selection, even when present with low frequency, may become a barrier to the use of 1^st-generation NNRTIs and the increased costs associated with regimen failure and disease progression underlie the importance of identification of treatment resistance to ensure optimal initial therapy choice and regimen succession.

The emerging and re-emerging human immunodeficiency virus epidemics in Europe

We provide a summary of the current status of the human immunodeficiency virus (HIV) epidemic, including data on the transmission of drug-resistant virus in the European Region of the WHO. The review was conducted by searching the reports of the European Centre for Disease Prevention and Control and the United Nations General Assembly Special Session country reports to identify the number of HIV cases reported in 2002-2011, the number of HIV tests performed, and the results of the most recent HIV surveys in at-risk groups. In the West, a 5-year linear trend analysis suggests an increase in the number of reported HIV cases in Belgium, Greece, and Iceland, and a decline in The Netherlands, Ireland, Portugal, Switzerland, and the UK. In the Centre, the number of reported cases increased in Bulgaria and Turkey, and in the East, the number of reported cases increased in Armenia, Georgia, and Ukraine. Estonia and Latvia reported a significant downward trend. HIV transmission in men who have sex with men (MSM) and heterosexual transmission accounted for, respectively, 40% and 38% of newly reported HIV cases in the West in 2011, whereas the epidemic in the Centre is predominantly concentrated in MSM. Although injection drug use remains the key driving force of the epidemic in the East, there is increasing evidence of sexual transmission from the core groups of injection drug users, and increasing spread within MSM. The pattern of transmitted drug resistance (TDR) is heterogeneous accross Europe; a significant number of clusters of TDR have been recently observed in several European countries.

The emergence of drug resistant HIV variants and novel anti-retroviral therapy

After its identification in 1980s, HIV has infected more than 30 million people worldwide. In the era of highly active anti-retroviral therapy, anti-retroviral drug resistance results from insufficient anti-retroviral pressure, which may lead to treatment failure. Preliminary studies support the idea that anti-retroviral drug resistance has evolved largely as a result of low-adherence of patients to therapy and extensive use of anti-retroviral drugs in the developed world; however, a highly heterogeneous horde of viral quasi-species are currently circulating in developing nations. Thus, the prioritizing of strategies adopted in such two worlds should be quite different considering the varying anti-retroviral drug resistance prevalence. In this article, we explore differences in anti-retroviral drug resistance patterns between developed and developing countries, as they represent two distinct ecological niches of HIV from an evolutionary standpoint.

Running loose or getting lost: how HIV-1 counters and capitalizes on APOBEC3-induced mutagenesis through its Vif protein

Human immunodeficiency virus-1 (HIV-1) dynamics reflect an intricate balance within the viruses’ host. The virus relies on host replication factors, but must escape or counter its host’s antiviral restriction factors. The interaction between the HIV-1 protein Vif and many cellular restriction factors from the APOBEC3 protein family is a prominent example of this evolutionary arms race. The viral infectivity factor (Vif) protein largely neutralizes APOBEC3 proteins, which can induce in vivo hypermutations in HIV-1 to the extent of lethal mutagenesis, and ensures the production of viable virus particles. HIV-1 also uses the APOBEC3-Vif interaction to modulate its own mutation rate in harsh or variable environments, and it is a model of adaptation in a coevolutionary setting. Both experimental evidence and the substantiation of the underlying dynamics through coevolutionary models are presented as complementary views of a coevolutionary arms race.

Increase in transmitted HIV drug resistance among persons undergoing genotypic resistance testing in Ontario, Canada, 2002-09

OBJECTIVES

To characterize persons undergoing HIV genotypic resistance testing (GRT) while treatment naive and to estimate the prevalence of transmitted HIV drug resistance (TDR) among HIV-positive outpatients in Ontario, Canada.

METHODS

We analysed data from a multi-site cohort of persons receiving HIV care. Data were obtained from medical chart abstractions, interviews and record linkage with the Public Health Laboratories, Public Health Ontario. The analysis was restricted to 626 treatment-naive persons diagnosed in 2002-09. TDR mutations were identified using the calibrated population resistance tool. We used descriptive statistics and regression methods to characterize treatment-naive GRT test uptake and patterns of TDR.

RESULTS

Overall, 53.2% (333/626) of participants had baseline GRT. The proportion increased with year of HIV diagnosis from 30.0% in 2002 to 82.6% in 2009 (P < 0.0001). Among those tested, 13.6% (CI 9.9-17.3%) had one or more drug resistance mutations, and 8.8% (CI 5.7-11.8%), 4.8% (CI 2.5-7.2%) and 2.7% (CI 1.0-4.5%) had mutations conferring resistance to nucleoside/tide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs), respectively. TDR prevalence increased from 2002-07 to 2008-09 (adjusted OR 3.7, 95% CI 1.7-8.2), driven by a higher proportion with NRTI (18.2% versus 5.9%, P = 0.0009) and NNRTI mutations (11.7% versus 2.8%, P = 0.004) in the later time period. PI TDR remained unchanged.

CONCLUSIONS

Baseline GRT increased dramatically since 2002, but remains below 100%. The prevalence of overall TDR tripled due to increases in NRTI and NNRTI mutations. These findings highlight the value of routine baseline GRT for TDR surveillance and patient care.