Letter to the editor: Pre-exposure prophylaxis for HIV in Europe: The need for resistance surveillance

__To the editor:__ In a recent paper by Hauser et al. in this journal, a prevalence of 10.8% of transmitted drugresistant viruses was reported among newly diagnosed HIV cases in Germany in 2013 and 2014. The authors conclude that genotypic resistance testing remains important for treatment as well as HIV prevention. We comment on the use of pre-exposure prophylaxis (PrEP) in relation to drug resistance in HIV infections and the need for European surveillance of drug resistance

Drug resistance in non-B subtype HIV-1: Impact of HIV-1 reverse transcriptase inhibitors

Human immunodeficiency virus (HIV) causes approximately 2.5 million new infections every year, and nearly 1.6 million patients succumb to HIV each year. Several factors, including cross-species transmission and error-prone replication have resulted in extraordinary genetic diversity of HIV groups. One of these groups, known as group M (main) contains nine subtypes (A-D, F-H and J-K) and causes ∼95% of all HIV infections. Most reported data on susceptibility and resistance to anti-HIV therapies are from subtype B HIV infections, which are prevalent in developed countries but account for only ∼12% of all global HIV infections, whereas non-B subtype HIV infections that account for ∼88% of all HIV infections are prevalent primarily in low and middle-income countries. Although the treatments for subtype B infections are generally effective against non-B subtype infections, there are differences in response to therapies. Here, we review how polymorphisms, transmission efficiency of drug-resistant strains, and differences in genetic barrier for drug resistance can differentially alter the response to reverse transcriptase-targeting therapies in various subtypes

Effectiveness of current anti-HIV regimen in low-and middle-income countries

Nevirapine (NVP) is a first-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) of human immunodeficiency virus type 1 (HIV-1). However, with the emergence of resistance mutations due to a low genetic barrier under NVP pressure, new (second generation) NNRTIs have been approved. Rilpivirine (RPV), a second generation NNRTI, is not frequently used in low- and middle- income countries (LMICs) that bear the major HIV burden. RPV has been co-formulated with tenofovir (TDF) and emtricitabine (FTC) and has been recommended for patients with viral loads <100,000 copies/mL, inhibiting viruses that are resistant to NVP. It is now being considered in many LMICs. To understand RPV efficacy in HIV-1 subtypes prevalent in LMICs, we cloned RT genes from patients infected with four different HIV-1 subtypes: subtype B (HIV-1B), subtype C (HIV-1C), and recombinant forms CRF01_AE and CRF02_AG. HIV-1B is most prevalent in western countries and accounts for only ~12% of all infections. However, HIV-1C, which accounts for ~52% of all HIV infections, is most prevalent in LMICs. In vitro inhibition assays were performed with the four patient-derived RTs. Our results show that overall, NVP binds RTs with lower affinity than RPV, suggesting that NVP has lower effectiveness than RPV. However, NV binds 02_AG RT with better affinity than RPV. Hence, NVP may still be effective for patients infected with 02_AG. Furthermore, RPV binding affinity with HIV-1C is lower than other subtypes. This result is consistent with clinical results, showing less efficacy of RPV among HIV-1C infected patients

T-bet and Eomes Are Differentially Linked to the Exhausted Phenotype of CD8+T Cells in HIV Infection

CD8+ T cell exhaustion represents a major hallmark of chronic HIV infection. Two key transcription factors governing CD8+ T cell differentiation, T-bet and Eomesodermin (Eomes), have previously been shown in mice to differentially regulate T cell exhaustion in part through direct modulation of PD-1. Here, we examined the relationship between these transcription factors and the expression of several inhibitory receptors (PD-1, CD160, and 2B4), functional characteristics and memory differentiation of CD8+ T cells in chronic and treated HIV infection. The expression of PD-1, CD160, and 2B4 on total CD8+ T cells was elevated in chronically infected individuals and highly associated with a T-betdimEomeshi expressional profile. Interestingly, both resting and activated HIV-specific CD8+ T cells in chronic infection were almost exclusively T-betdimEomeshi cells, while CMV-specific CD8+ T cells displayed a balanced expression pattern of T-bet and Eomes. The T-betdimEomeshi virus-specific CD8+ T cells did not show features of terminal differentiation, but rather a transitional memory phenotype with poor polyfunctional (effector) characteristics. The transitional and exhausted phenotype of HIV-specific CD8+ T cells was longitudinally related to persistent Eomes expression after antiretroviral therapy (ART) initiation. Strikingly, these characteristics remained stable up to 10 years after ART initiation. This study supports the concept that poor human viral-specific CD8+ T cell functionality is due to an inverse expression balance between T-bet and Eomes, which is not reversed despite long-term viral control through ART. These results aid to explain the inability of HIV-specific CD8+ T cells to control the viral replication post-ART cessation

The HIV continuum of care in European Union countries in 2013: data and challenges

BACKGROUND: UNAIDS has set a 90-90-90 target to curb the HIV epidemic by 2020, but methods used to assess whether countries have reached this target are not standardised, hindering comparisons. METHODS: Through a collaboration formed by the European Centre for Disease Prevention and Control (ECDC) with European HIV cohorts and surveillance agencies, we constructed a standardised, four-stage continuum of HIV care for 11 European Union (EU) countries for 2013. Stages were defined as: 1) number of people living with HIV (PLHIV) in the country by end of 2013; 2) proportion of stage 1 ever diagnosed; 3) proportion of stage 2 ever initiated ART; and 4) proportion of stage 3 who became virally-suppressed (≤200 copies/mL). Case surveillance data were used primarily to derive stages 1 (using back-calculation models) and 2, and cohort data for stages 3 and 4. RESULTS: In 2013, 674,500 people in the 11 countries were estimated to be living with HIV, ranging from 5,500 to 153,400 in each country. Overall HIV prevalence was 0.22% (range 0.09%-0.36%). Overall proportions, of each previous stage, were 84% diagnosed, 84% on ART, and 85% virally-suppressed (60% of PLHIV). Two countries achieved ≥90% for all stages, and over half had reached ≥90% for at least one stage. CONCLUSIONS: EU countries are nearing the 90-90-90 target. Reducing the proportion undiagnosed remains the greatest barrier to achieving this target, suggesting further efforts are needed to improve HIV testing rates. Standardising methods to derive comparable continuums of care remains a challenge

A21 HIV-1 sub-subtype F1 outbreak among MSM in Belgium

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Human Immunodeficiency Virus Continuum of Care in 11 European Union Countries at the End of 2016 Overall and by Key Population: Have We Made Progress?

High uptake of antiretroviral treatment (ART) is essential to reduce human immunodeficiency virus (HIV) transmission and related mortality; however, gaps in care exist. We aimed to construct the continuum of HIV care (CoC) in 2016 in 11 European Union (EU) countries, overall and by key population and sex. To estimate progress toward the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 target, we compared 2016 to 2013 estimates for the same countries, representing 73% of the population in the region. A CoC with the following 4 stages was constructed: number of people living with HIV (PLHIV); proportion of PLHIV diagnosed; proportion of those diagnosed who ever initiated ART; and proportion of those ever treated who achieved viral suppression at their last visit. We estimated that 87% of PLHIV were diagnosed; 92% of those diagnosed had ever initiated ART; and 91% of those ever on ART, or 73% of all PLHIV, were virally suppressed. Corresponding figures for men having sex with men were: 86%, 93%, 93%, 74%; for people who inject drugs: 94%, 88%, 85%, 70%; and for heterosexuals: 86%, 92%, 91%, 72%. The proportion suppressed of all PLHIV ranged from 59% to 86% across countries. The EU is close to the 90-90-90 target and achieved the UNAIDS target of 73% of all PLHIV virally suppressed, significant progress since 2013 when 60% of all PLHIV were virally suppressed. Strengthening of testing programs and treatment support, along with prevention interventions, are needed to achieve HIV epidemic control.This work was supported by the European Centre for Disease Prevention and Control through a framework contract (ECDC/2016/028).S

Integrase Strand Transfer Inhibitor Use and Cancer Incidence in a Large Cohort Setting

Background: Limited data exist examining the association between incident cancer and cumulative integrase inhibitor (INSTI) exposure. Methods: Participants were followed from baseline (latest of local cohort enrollment or January 1, 2012) until the earliest of first cancer, final follow-up, or December 31, 2019. Negative binomial regression was used to assess associations between cancer incidence and time-updated cumulative INSTI exposure, lagged by 6 months. Results: Of 29 340 individuals, 74% were male, 24% were antiretroviral treatment (ART)-naive, and median baseline age was 44 years (interquartile range [IQR], 36-51). Overall, 13 950 (48%) individuals started an INSTI during follow-up. During 160 657 person-years of follow-up ([PYFU] median 6.2; IQR, 3.9-7.5), there were 1078 cancers (incidence rate [IR] 6.7/1000 PYFU; 95% confidence interval [CI], 6.3-7.1). The commonest cancers were non-Hodgkin lymphoma (n=113), lung cancer (112), Kaposi's sarcoma (106), and anal cancer (103). After adjusting for potential confounders, there was no association between cancer risk and INSTI exposure (≤6 months vs no exposure IR ratio: 1.15 [95% CI, 0.89-1.49], &gt;6-12 months; 0.97 [95% CI, 0.71-1.32], &gt;12-24 months; 0.84 [95% CI, 0.64-1.11], &gt;24-36 months; 1.10 [95% CI, 0.82-1.47], &gt;36 months; 0.90 [95% CI, 0.65-1.26] [P=.60]). In ART-naive participants, cancer incidence decreased with increasing INSTI exposure, mainly driven by a decreasing incidence of acquired immune deficiency syndrome cancers; however, there was no association between INSTI exposure and cancer for those ART-experienced (interaction P&lt;.0001). Conclusions: Cancer incidence in each INSTI exposure group was similar, despite relatively wide CIs, providing reassuring early findings that increasing INSTI exposure is unlikely to be associated with an increased cancer risk, although longer follow-up is needed to confirm this finding