The influence of human leukocyte antigen-types on disease progression among HIV-2 infected patients in Guinea-Bissau

The HIV care continuum of Guinea-Bissau; Progress towards the UNAIDS 90-90-90 targets for HIV-1 and HIV-2

OBJECTIVE

In the 2020 UNAIDS HIV treatment goals, 90% of people living with HIV (PLHIV) should be diagnosed, 90% of these should receive antiretroviral treatment (ART) and 90% of these should be virally suppressed. We aimed to evaluate whether Guinea-Bissau fulfills the 2020 treatment goals for both for HIV-1 and HIV-2.

DESIGN

By combining data from a general population survey, treatment records from HIV clinics across Guinea-Bissau and a biobank from patients attending the largest HIV clinics in Bissau, we estimated each column of the 90-90-90 cascade.

METHOD

2601 participated in the survey and were used to estimate the proportion of PLHIV who knew their HIV status and the proportion of PLHIV on ART. Answers given in the survey was verified with treatment records from HIV clinics. We measured viral load from biobank materials from HIV patients and estimated the proportion of virally suppressed PLHIV.

RESULT

19.1% of PLHIV indicated to be aware of their HIV status. Of these, 48.5% received ART, and 76.4% of these were virally suppressed. For HIV-1 and HIV-1/2 the results were 21.2%, 40.9% and 75.1%. For HIV-2 the results were 15.9%, 63.6% and 80.7%. 26.9% of all HIV-1 infected in the survey were virologically suppressed, indicating that a much higher number of HIV-1 infected were aware of their status and on treatment.

CONCLUSION

Guinea-Bissau lags severely behind both the global and regional progress. Improvement in both testing and treating HIV is necessary to improve the quality of care.

Performance evaluation of a laboratory developed PCR test for quantitation of HIV-2 viral RNA

Management of Human Immunodeficiency Virus Type 2 (HIV-2) infections present unique challenges due to low viral titers, slow disease progression, and poor response to standard antiviral therapies. The need for a nucleic acid assay to detect and quantify HIV-2 virus has led to the development of a number of molecular-based assays for detection and/or quantification of HIV-2 viral RNA in plasma in order to provide laboratory evidence of HIV-2 infection and viral loads for use in treatment decisions. As HIV-2 is less pathogenic and transmissible than HIV-1 and has resistance to several of the antiretroviral drugs, delay of treatment is common. Cross sero-reactivity between HIV-1 and HIV-2 makes it difficult to distinguish between the two viruses based upon serological tests. As such we developed a quantitative reverse transcription PCR (qRT-PCR) assay targeting the 5' long terminal repeat of HIV-2 for detection and quantification of HIV-2 viral RNA in plasma to identify HIV-2 infection and for use in viral load monitoring. Serial dilutions of cultured HIV-2 virus demonstrated a wide dynamic range (10 to 100,000 copies/ml) with excellent reproducibility (standard deviation from 0.12-0.19), linearity (R2 = 0.9994), and a lower limit of detection at 79 copies/ml (NIH-Z). The assay is highly specific for HIV-2 Groups A and B and exhibits no cross reactivity to HIV-1, HBV or HCV. Precision of the assay was demonstrated for the High (Mean = 6.41; SD = 0.12) and Medium (Mean = 4.46; SD = 0.13) HIV-2 positive controls. Replicate testing of clinical specimens showed good reproducibility above 1,000 copies/ml, with higher variability under 1,000 copies/ml. Analysis of 220 plasma samples from HIV-2 infected West African individuals demonstrated significantly lower viral loads than those observed in HIV-1 infections, consistent with results of previous studies. Slightly more than seven percent of clinical samples (7.3%) demonstrated viral loads above 100,000 copies/ml, while 37.3% of samples were undetectable. The high sensitivity, specificity, precision, and linearity of the WRAIR qRT-PCR assay makes it well suited for detection and monitoring of HIV-2 RNA levels in plasma of infected individuals.

Discriminatory rapid tests cause HIV-type misclassification-evaluation of three rapid tests using clinical samples from Guinea-Bissau

BACKGROUND

Discrimination among HIV types is important because HIV-2 is naturally resistant to some of the first-line drugs used in the treatment of HIV-1. We evaluated three assays for HIV-type discriminatory capacity: SD Bioline HIV 1/2 3.0 (Bioline), First Response HIV 1-2-0 Card Test (First Response) and Genie III HIV-1/HIV-2 (Genie III).

METHODS

Based on results from the Bioline assay, samples from 239 HIV-infected patients from the Bissau HIV cohort in Guinea-Bissau were retrospectively selected for evaluation. Genie III and First Response were scored by three independent readers and compared with a reference test (INNO-LIA HIV I/II Score) confirmed by HIV RNA as well as DNA detection.

RESULTS

The best performing test was Genie III, with an average agreement with the reference test of 93.4%, followed by First Response (86.1%) and Bioline (72.4%). First Response and Bioline were scored with a false high number of HIV-1/2 dual infections. For both First Response and Genie III, there were discrepancies among independent readers, and some tests were scored as HIV non-reactive.

CONCLUSIONS

Using these rapid tests with a suboptimal performance will presumably result in a high rate of false HIV-1/2 dual diagnoses, depriving patients of alternative treatment options in cases of treatment failure.

HIV-2 as a model to identify a functional HIV cure

Two HIV virus types exist: HIV-1 is pandemic and aggressive, whereas HIV-2 is confined mainly to West Africa and less pathogenic. Despite the fact that it has been almost 40 years since the discovery of AIDS, there is still no cure or vaccine against HIV. Consequently, the concepts of functional vaccines and cures that aim to limit HIV disease progression and spread by persistent control of viral replication without life-long treatment have been suggested as more feasible options to control the HIV pandemic. To identify virus-host mechanisms that could be targeted for functional cure development, researchers have focused on a small fraction of HIV-1 infected individuals that control their infection spontaneously, so-called elite controllers. However, these efforts have not been able to unravel the key mechanisms of the infection control. This is partly due to lack in statistical power since only 0.15% of HIV-1 infected individuals are natural elite controllers. The proportion of long-term viral control is larger in HIV-2 infection compared with HIV-1 infection. We therefore present the idea of using HIV-2 as a model for finding a functional cure against HIV. Understanding the key differences between HIV-1 and HIV-2 infections, and the cross-reactive effects in HIV-1/HIV-2 dual-infection could provide novel insights in developing functional HIV cures and vaccines.

T-cell and B-cell perturbations identify distinct differences in HIV-2 compared with HIV-1-induced immunodeficiency

BACKGROUND

For unknown reasons, HIV-2 is less pathogenic than HIV-1, and HIV-2-induced immunodeficiency may be different from that caused by HIV-1. Previous immunological studies have hinted at possible shifts in both T-cell and B-cell subsets, which we aimed to characterize further.

METHODS

From an HIV clinic in Guinea-Bissau, 63 HIV-2, 83 HIV-1, and 26 HIV-negative participants were included. All HIV-infected participants were ART-naive. The following cell subsets were analysed by flow cytometry; T cells (maturation and activation), regulatory T cells, and B cells (maturation and activation).

RESULTS

After standardizing for sex, age, and CD4 T-cell count HIV-2 had 0.938 log10 copies/ml lower HIV RNA levels than the HIV-1-infected patients. Whereas T-cell maturation and regulatory T-cell profiles were similar between patients, HIV-2-infected patients had higher proportions of CD8CD28 and lower proportions of CD8PD-1+ T cells than HIV-1-infected patients. This finding was independent of HIV RNA levels. HIV-2 was also associated with a more preserved proportion of naive B cells.

CONCLUSION

HIV-2 is characterized by lower viral load, and lower T-cell activation, which may account for the slower disease progression.

Delayed disease progression in HIV-2: the importance of TRIM5α and the retroviral capsid

HIV-2 is thought to have entered the human population in the 1930s through cross-species transmission of SIV from sooty mangabeys in West Africa. Unlike HIV-1, HIV-2 has not led to a global pandemic, and recent data suggest that HIV-2 prevalence is declining in some West African states where it was formerly endemic. Although many early isolates of HIV-2 were derived from patients presenting with AIDS-defining illnesses, it was noted that a much larger proportion of HIV-2-infected subjects behaved as long-term non-progressors (LTNP) than their HIV-1-infected counterparts. Many HIV-2-infected adults are asymptomatic, maintaining an undetectable viral load for over a decade. However, despite lower viral loads, HIV-2 progresses to clinical AIDS without therapeutic intervention in most patients. In addition, successful treatment with anti-retroviral therapy (ART) is more challenging than for HIV-1. HIV-2 is significantly more sensitive to restriction by host restriction factor tripartite motif TRIM5α than HIV-1, and this difference in sensitivity is linked to differences in capsid structure. In this review we discuss the determinants of HIV-2 disease progression and focus on the important interactions between TRIM5α and HIV-2 capsid in long-term viral control.

HLA-DQB1*06:276, a novel HLA allele fund in a patient from Guinea-Bissau

DQB1*06:276 differs from DQB1*06:03:01:01 by amino acid substitutions p.T71A, p.G74S, and p.L75V in exon 2.

Two novel HLA-B alleles, HLA-B*53:01:17 and -B*58:83, found in patients from Guinea-Bissau

Novel HLA-B alleles HLA-B*53:01:17 and HLA-B*58:83 are described in two patients from Guinea-Bissau.