Commentary: Decline of HIV-2 prevalence in West Africa: good news or bad news?

HIV-2 inhibits HIV-1 gene expression via two independent mechanisms during cellular co-infection

IMPORTANCE

Twenty-five years after the first report that HIV-2 infection can reduce HIV-1-associated pathogenesis in dual-infected patients, the mechanisms are still not well understood. We explored these mechanisms in cell culture and showed first that these viruses can co-infect individual cells. Under specific conditions, HIV-2 inhibits HIV-1 through two distinct mechanisms, a broad-spectrum interferon response and an HIV-1-specific inhibition conferred by the HIV-2 TAR. The former could play a prominent role in dually infected individuals, whereas the latter targets HIV-1 promoter activity through competition for HIV-1 Tat binding when the same target cell is dually infected. That mechanism suppresses HIV-1 transcription by stalling RNA polymerase II complexes at the promoter through a minimal inhibitory region within the HIV-2 TAR. This work delineates the sequence of appearance and the modus operandi of each mechanism.

Transfusion of HIV-infected blood products despite highly sensitive nucleic acid testing

BACKGROUND

In France, the risk of HIV transmission by transfusion was reduced by implementing pooled nucleic acid testing (NAT) in 2001 and individual NAT in 2010. We report here the first case in France of transfusion of human immunodeficiency virus (HIV)-infected blood donated during HIV pre-ramp-up phase that tested individual NAT negative.

METHODS

Blood donations are screened for HIV antibodies and HIV RNA (ProcleixUltrio, Grifols; limit of detection at 95%, 23 copies/mL). When a repeat donor tests positive for HIV, a repository sample from the previous donation is tested with the Cobas Taqman HIV-1 test (CTM, Roche; limit of detection at 95%, 17 copies/mL).

RESULTS

In August 2017, a 57-year-old male repeat donor was screened positive for HIV antibodies and RNA (plasma viral load, 11,599 copies/mL). The previous donation had tested negative with Ultrio in March 2017 but was positive with an unquantifiable plasma viral load when tested with CTM. Sequencing showed no mismatch between Ultrio primers/probes and the target sequence. HIV transmission was excluded by lookback studies in the recipient of platelets, which had been pathogen reduced, but not in the recipient of RBCs due to premature death.

CONCLUSION

This case demonstrates that the risk of contaminated donations due to the early HIV infection phase going undetected by highly sensitive NAT is real but exceptional. The absence of transmission to the platelets recipient could be due to the very low viral inoculum and/or to the efficacy of the viral inactivation. This case also highlights the additional value of a systematic donation archiving and the importance of donor education and predonation selection.

Near Full-Length Genomic Characterization of HIV-1 CRF01_AE/B Recombinant Strains Identified in Hebei, China

This study reports a novel HIV-1 recombinant form of CRF01_AE/B that was isolated from a 22-year-old male individual (HE150308) residing in Hebei province, China. The near full-length genome (NFLG) phylogenetic tree showed that the strain was clustered with CRF01_AE reference sequences and placed at the peripheral position within the branch of CRF01_AE strains. The bootscaning and similarity plot analysis revealed that the NFLG of this novel recombinant was composed of eight interlaced segments, including four CRF01_AE and four subtype B segments separated by seven breakpoints observed in the gag, pol, and nef regions of HIV-1 genome. Phylogenetic analysis demonstrated that the CRF01_AE subregions were from the previously identified CRF01_AE cluster 5, and the B subregions were correlated with the B strains originated from Europe and America. They were all the lineages widely prevalent in men who have sex with men (MSM) population in China. In recent years, a large number of recombinants between CRF01_AE and B strains are constantly emerging in the MSM population in China. This continual and recurrent recombination between CRF01_AE and B in high-risk group people deserves more attention and further monitoring.

90-90-90 for HIV-2? Ending the HIV-2 epidemic by enhancing care and clinical management of patients infected with HIV-2

Distinct from HIV-1 and often neglected in the global campaign to end the AIDS epidemic, HIV-2 presents unique and underappreciated challenges in diagnosis, clinical care, antiretroviral therapy (ART), and HIV programmatic management. Here, we review the epidemiology and natural history of HIV-2, diagnostics and algorithms for accurately diagnosing and differentiating HIV-2 from HIV-1, the unique features of HIV-2 ART and drug resistance, and the clinical care and management of patients infected with HIV-2 in both developed and resource-limited settings. Ultimately, further research is needed to address the gaps in our knowledge of HIV-2 infection, increased resources are needed to specifically target HIV-2 as part of the UNAIDS/WHO 90-90-90 campaign to end AIDS, and increased determination is needed to better advocate for inclusion of people living with HIV-2 in global HIV/AIDS initiatives.

Immunologic response in treatment-naïve HIV-2-infected patients: the IeDEA West Africa cohort

INTRODUCTION

Response to antiretroviral therapy (ART) among individuals infected with HIV-2 is poorly described. We compared the immunological response among patients treated with three nucleoside reverse-transcriptase inhibitors (NRTIs) to boosted protease inhibitor (PI) and unboosted PI-based regimens in West Africa.

METHODS

This prospective cohort study enrolled treatment-naïve HIV-2-infected patients within the International Epidemiological Databases to Evaluate AIDS collaboration in West Africa. We used mixed models to compare the CD4 count response to treatment over 12 months between regimens.

RESULTS

Of 422 HIV-2-infected patients, 285 (67.5%) were treated with a boosted PI-based regimen, 104 (24.6%) with an unboosted PI-based regimen and 33 (7.8%) with three NRTIs. Treatment groups were comparable with regard to gender (54.5% female) and median age at ART initiation (45.3 years; interquartile range 38.3 to 51.8). Treatment groups differed by clinical stage (21.2%, 16.8% and 17.3% at CDC Stage C or World Health Organization Stage IV for the triple NRTI, boosted PI and unboosted PI groups, respectively, p=0.02), median length of follow-up (12.9, 17.7 and 44.0 months for the triple NRTI, the boosted PI and the unboosted PI groups, respectively, p<0.001) and baseline median CD4 count (192, 173 and 129 cells/µl in the triple NRTI, the boosted PI and the unboosted PI-based regimen groups, respectively, p=0.003). CD4 count recovery at 12 months was higher for patients treated with boosted PI-based regimens than those treated with three NRTIs or with unboosted PI-based regimens (191 cells/µl, 95% CI 142 to 241; 110 cells/µl, 95% CI 29 to 192; 133 cells/µl, 95% CI 80 to 186, respectively, p=0.004).

CONCLUSIONS

In this observational study using African data, boosted PI-containing regimens had better immunological response compared to triple NRTI combinations and unboosted PI-based regimens at 12 months. A randomized clinical trial is still required to determine the best initial regimen for treating HIV-2 infected patients.

Antiretroviral therapy response among HIV-2 infected patients: a systematic review

BACKGROUND

Few data are available on antiretroviral therapy (ART) response among HIV-2 infected patients. We conducted a systematic review on treatment outcomes among HIV-2 infected patients on ART, focusing on the immunological and virological responses in adults.

METHODS

Data were extracted from articles that were selected after screening of PubMed/MEDLINE up to November 2012 and abstracts of the 1996-2012 international conferences. Observational cohorts, clinical trials and program reports were eligible as long as they reported data on ART response (clinical, immunological or virological) among HIV-2 infected patients. The determinants investigated included patients' demographic characteristics, CD4 cell count at baseline and ART received.

RESULTS

Seventeen reports (involving 976 HIV-2 only and 454 HIV1&2 dually reactive patients) were included in the final review, and the analysis presented in this report are related to HIV-2 infected patients only. There was no randomized controlled trial and only two cohorts had enrolled more than 100 HIV-2 only infected patients. The median CD4 count at ART initiation was 165 cells/mm3, [IQR; 137-201] and the median age at ART initiation was 44 years (IQR: 42-48 years). Ten studies included 103 patients treated with three nucleoside reverse transcriptase inhibitors (NRTI). Protease inhibitor (PI) based regimens were reported by 16 studies. Before 2009, the most frequent PIs used were Nelfinavir and Indinavir, whereas it was Lopinavir/ritonavir thereafter. The immunological response at month-12 was reported in six studies and the mean CD4 cell count increase was +118 cells/μL (min-max: 45-200 cells/μL).

CONCLUSION

Overall, clinical and immuno-virologic outcomes in HIV-2 infected individuals treated with ART are suboptimal. There is a need of randomized controlled trials to improve the management and outcomes of people living with HIV-2 infection.

HIV-1/HIV-2 co-infection among voluntary counselling and testing subjects at a regional hospital in Cameroon

BACKGROUND

HIV/AIDS is a major public health problem in Cameroon which had a prevalence of 5.1% in 2010 with 141 new infections per day. The fear of voluntary counseling and testing (VCT) is an obstacle to HIV prevention.

OBJECTIVES

To determine the prevalence of HIV-1, HIV-2 and HIV-1/HIV-2 co-infection among people attending a health facility for VCT.

METHODS

Venous blood was collected from participants using aseptic techniques in a descriptive observational cross-sectional study. DETERMINE HIV-1/2 and SD BIOLINE HIV-1/2 3.0 qualitative tests were used for the detection of HIV-1 and HIV-2 in their sera. Range and consistency checks were carried out on the data and analysed using Epi-Info.

RESULTS

Of 290 individuals tested, 78(26.9%) were positive for HIV-1 and HIV-2. Among the 78 HIV positive individuals, 62 (79.5%) had HIV-1, 1(1.3%) had HIV-2 and 15(19.2%) had concurrent HIV-1/ HIV-2. Among those infected, 57(73.1%) were females including 21(26.9%) males.

CONCLUSION

HIV-1 is the major cause of AIDS and VCT is well accepted. Co-infection with HIV-1/HIV-2 may lead to anti-retroviral drug resistance. VCT should be encouraged so that positive cases can initiate therapy on time to stay ahead of anti-retroviral drug resistance.

The Use of Bioinformatics for Studying HIV Evolutionary and Epidemiological History in South America

The South American human immunodeficiency virus type 1 (HIV-1) epidemic is driven by several subtypes (B, C, and F1) and circulating and unique recombinant forms derived from those subtypes. Those variants are heterogeneously distributed around the continent in a country-specific manner. Despite some inconsistencies mainly derived from sampling biases and analytical constrains, most of studies carried out in the area agreed in pointing out specificities in the evolutionary dynamics of the circulating HIV-1 lineages. In this paper, we covered the theoretical basis, and the application of bioinformatics methods to reconstruct the HIV spatial-temporal dynamics, unveiling relevant information to understand the origin, geographical dissemination and the current molecular scenario of the HIV epidemic in the continent, particularly in the countries of Southern Cone.

First-year lymphocyte T CD4+ response to antiretroviral therapy according to the HIV type in the IeDEA West Africa collaboration

OBJECTIVE

To compare the lymphocyte T CD4+ (CD4) response to combinations of antiretroviral therapy (ART) in HIV-1, HIV-2 and dually positive patients in West Africa.

DESIGN AND SETTING

Collaboration of 12 prospective cohorts of HIV-infected adults followed in Senegal (2), Gambia (1), Mali (2), Benin (1) and Côte d'Ivoire (6).

SUBJECTS

Nine thousand, four hundred and eighty-two patients infected by HIV-1 only, 270 by HIV-2 only and 321 dually positive, who initiated an ART.

OUTCOME MEASURES

CD4 change over a 12-month period.

RESULTS

Observed CD4 cell counts at treatment initiation were similar in the three groups [overall median 155, interquartile range (IQR) 68; 249 cells/microl). In HIV-1 patients, the most common ART regimen was two nucleoside reverse transcriptase inhibitors (NRTIs) and one non-nucleoside reverse transcriptase inhibitor (NNRTI; N = 7714) as well as for dually positive patients (N = 135). HIV-2 patients were most often treated with a protease inhibitor-based regimen (N = 193) but 45 of them were treated with an NNRTI-containing ART. In those treated with a NNRTI-containing regimen, the estimated mean CD4 change between 3 and 12 months was significantly lower in HIV-2 (-41 cells/microl per year) and dually positive patients (+12 cells/microl per year) compared to HIV-1 patients (+69 cells/microl per year, overall P value 0.01). The response in HIV-2 and dually positive patients treated by another regimen (triple NRTIs or protease inhibitor-containing ART) was not significantly different than the response obtained in HIV-1-only patients (all P values >0.30).

CONCLUSION

An optimal CD4 response to ART in West Africa requires determining HIV type prior to initiation of antiretroviral drugs. NNRTIs are the mainstay of first-line ART in West Africa but are not adapted to the treatment of HIV-2 and dually positive patients.

Drug resistance differences among HIV types and subtypes: a growing problem

Although HIV-1 subtype B accounts for only 10% of worldwide HIV infections, almost all knowledge regarding antiretroviral (ARV) drug development and viral resistance is based on this subtype. More recently, an increasing body of evidence suggests that distinct HIV genetic variants possess different biological properties, including susceptibility and response to ARVs. In this review, we will summarize recent in vitro and in vivo studies reporting such differences. In general terms, infections with most HIV variants respond well to ARVs, but minor differences in susceptibility, in the emergence and selection of subtype-specific drug resistance mutations and in the acquisition of similar mutations over the period of ARV exposure have been reported. Such differences impact on drugresistance interpretation algorithms, which are mostly based on inference from sequence information. Despite the differences observed, clinical response to ARV therapy among subjects infected with distinct HIV variants is effective, and the dissemination of ARV access in developing countries where non-B subtypes prevail should not be delayed.