Plasma Cytokine Biomarker Cutoff Values for HIV-Associated Neurocognitive Impairment in Adults.

Diagnosing HIV-associated neurocognitive impairment in most high-burden, but resource-constrained, settings is difficult due to the unavailability of specialist neurologists and neuropsychologists in primary health care centers. New tests that are easy to perform, based on virological and host immune response biomarkers, may be valuable in the diagnosis of HIV-associated neurocognitive disorder. The receiver operator characteristic curve analysis was used to investigate the diagnostic accuracy of threshold/cutoff concentrations for the peripheral lymphocyte proviral load and plasma biomarkers as diagnostic candidates for neurocognitive impairment in 133 HIV-infected individuals, using global deficit scores as the clinical gold standard. Forty-five (33.83%) of the participants had HIV-associated neurocognitive impairment, with 17.29% being mildly impaired and 16.54% moderately impaired. IL-2 had the best performance as a diagnostic tool for neurocognitive impairment with sensitivity of 67% and specificity of 52%, while the lowest performance was IL-6 with 65% sensitivity and 39% specificity. MIP-1α had the highest precision for the cutoff value, as indicated by the narrow 95% confidence interval (CI) (2.23-3.27), followed by IL-2 with 95% CI (3.02-5.12). RANTES had least precision, as shown by the widest 95% CI (135-9,487.61). For clinical markers of HIV diagnosis and monitoring, the lymphocyte proviral load cutoff value of 145 genome copies/million cells had the highest accuracy with 60% sensitivity and 51% specificity. The plasma viral load had an imperfect balance of 46% sensitivity and 78% specificity. The study demonstrated low to medium diagnostic accuracy of plasma cytokine biomarker cutoff values for defining neurocognitive impairment in people living with HIV.

Plasma Cytokine Levels As Predictors of Global and Domain-Specific Human Immunodeficiency Virus-Associated Neurocognitive Impairment in Treatment-Naive Individuals.

Central nervous system dysfunction, associated with human immunodeficiency virus (HIV) infection, remains a significant clinical concern, affecting at least 50% of infected people. Imbalances in cytokine expression levels have been linked to HIV-associated neurocognitive disorders. The aim of this study was to evaluate plasma cytokine levels as predictor neurocognitive impairment in HIV infection using a multiplex profiling kit. Stepwise regression model was used to identify cytokine biomarkers of overall and domain-specific cognitive performance. Higher interleukin (IL)-2 (ß = 0.04; P = 0.001) and eotaxin (ß = 0.01; P = 0.017) were predictors of global neurocognitive, whereas higher IL-5 (ß = 0.005; P = 0.007) was negative predictor of global cognitive deficit. IL-2 was a negative predictor of most cognitive domain functions, including recall (ß = 0.24; P = 0.005), recognition (ß = 0.04; P = 0.026), mental control (ß = 0.38; P = 0.005), symbol search (ß = -0.55; P = 0.001), and digital symbol (ß = -0.79; P = 0.019). IL-6 was associated with 3 impaired domains, mental processing (ß = -0.468; P = 0.027), recognition (ß = -0.044; P = 0.012), and learning (ß = 0.02668; P = 0.020) These results show that plasma cytokines/chemokines may serve as markers of neurocognitive impairment in HIV infection.

Involvement of CD95 and ligand in CD4+ T-cell and CD8+ T-cell depletion and hepatic cytolysis in patients with chronic viral hepatitis B.

BACKGROUND: Chronic viral hepatitis B (HBV) is characterised by progressive hepatocyte destruction and T-cell depletion. The mechanisms of the CD95-CD95 ligand (CD95L) signalling pathway during this chronic disease and the cirrhotic process remains unclear. OBJECTIVE: We evaluated the involvement of the CD95-CD95L receptor-ligand system in T-cell depletion and hepatic cytolysis in patients with chronic HBV. METHODS: This was a cross-sectional study conducted from September to December 2018 at the Yaoundé General Hospital, Cameroon. Four mL of whole blood was collected and analysed. The CD95 and CD95L levels, as well as the CD4+ T-cell and CD8+ T-cell counts, were performed by enzyme-linked immunosorbent assay and flow cytometry. RESULTS: Of the 130 HBV-positive patients, 36 (27.7%) were cirrhotic and 94 (72.3%) were non-cirrhotic. The cirrhotic patients had significantly elevated CD95 (p < 0.001) and CD95L (p = 0.001) plasma levels, compared with non-cirrhotic patients. The CD4/CD8 ratios were lower in cirrhotic patients, compared to non-cirrhotic patients (p < 0.001). There were statistically significant correlations between CD95 level and CD4+ T-cell counts, between CD95 level and CD8+ T-cell counts, between CD95 level and the CD4/CD8 ratio, between CD95 level and fibrosis score, and between CD95L level and fibrosis score. CONCLUSION: CD95 and CD95L could be involved in T-cell depletion and hepatic cytolysis during the pathogenesis of chronic HBV and could potentially be used as biomarkers for immunological and hepatic monitoring in patients with chronic HBV.

Impact of Plasma IP-10/CXCL10 and RANTES/CCL5 Levels on Neurocognitive Function in HIV Treatment-Naive Patients.

Immune activation, which is accompanied by the production of proinflammatory cytokines, is a strong predictor of disease progression in HIV infection. Inflammation is critical in neuronal damage linked to HIV-associated neurocognitive disorders. We examined the relationship between plasma cytokine levels and deficits in neurocognitive function. Multiplex profiling by Luminex® technology was used to quantify 27 cytokines/chemokines from 139 plasma samples of people living with HIV (PLWH). The relationship of plasma cytokine markers, clinical parameters, and cognitive impairment, was assessed using Spearman correlations. Partial least squares regression and variable importance in projection scores were used for further evaluation of the association. Forty-nine (35.3%) participants exhibited neurocognitive impairment based on a global deficit score (GDS) of at least 0.5 and 90 (64.7%) were classified as nonimpaired. Twenty-three (16.5%) initiated on combination antiretroviral therapy for 4 weeks before cognitive assessment and 116 (83.5%) were not on treatment. We identified five proinflammatory cytokines that were significant predictors of GDS namely, IP-10 (ß = 0.058; p = .007), RANTES (ß = 0.049; p = .005), IL-2 (ß = 0.047, p = .006), Eotaxin (ß = 0.042, p = .003), and IL-7 (ß = 0.039, p = .003). IP-10 and RANTES were the strongest predictors of GDS. Both cytokines correlated with plasma viral load and lymphocyte proviral load and were inversely correlated with CD4+ T cell counts. IP-10 and RANTES formed a separate cluster with highest proximity. Study findings describe novel associations among IP-10, RANTES, cognitive status, plasma viral load, and cell-associated viral load.

Structural Implications of Genotypic Variations in HIV-1 Integrase From Diverse Subtypes.

Human immunodeficiency virus type 1 (HIV-1) integrase (IN) integrates viral DNA into the host genome using its 3'-end processing and strand-transfer activities. Due to the importance of HIV-1 IN, it is targeted by the newest class of approved drugs known as integrase strand transfer inhibitors (INSTIs). INSTIs are efficient in maintaining low viral load; however, as with other approved antivirals, resistance mutations emerge in patients receiving INSTI-containing therapy. As INSTIs are becoming increasingly accessible worldwide, it is important to understand the mechanism(s) of INSTI susceptibility. There is strong evidence suggesting differences in the patterns and mechanisms of drug resistance between HIV-1 subtype B, which dominates in United States, Western Europe and Australia, and non-B infections that are most prevalent in countries of Africa and Asia. IN polymorphisms and other genetic differences among diverse subtypes are likely responsible for these different patterns, but lack of a full-length high-resolution structure of HIV-1 IN has been a roadblock in understanding the molecular mechanisms of INSTI resistance and the impact of polymorphisms on therapy outcome. A recently reported full-length medium-resolution cryoEM structure of HIV-1 IN provides insights into understanding the mechanism of integrase function and the impact of genetic variation on the effectiveness of INSTIs. Here we use molecular modeling to explore the structural impact of IN polymorphisms on the IN reaction mechanism and INSTI susceptibility.

Clinical Relevance of Total HIV DNA in Peripheral Blood Mononuclear Cell Compartments as a Biomarker of HIV-Associated Neurocognitive Disorders (HAND).

The pathogenesis of HIV-associated neurocognitive disorders is complex and multifactorial. It is hypothesized that the critical events initiating this condition occur outside the brain, particularly in the peripheral blood. Diagnoses of HIV-induced neurocognitive disorders largely rely on neuropsychometric assessments, which are not precise. Total HIV DNA in the peripheral blood mononuclear cells (PBMCs), quantified by PCR, correlate with disease progression, which is a promising biomarker to predict HAND. Numerous PCR assays for HIV DNA in cell compartments are prone to variation due to the lack of standardization and, therefore, their utility in predicting HAND produced different outcomes. This review evaluates the clinical relevance of total HIV DNA in circulating mononuclear cells using different published quantitative PCR (qPCR) protocols. The rationale is to shed light on the most appropriate assays and sample types used to accurately quantify HIV DNA load, which predicts severity of neurocognitive impairment. The role of monocytes as a vehicle for trafficking HIV into the CNS makes it the most suitable sample for determining a HAND associated reservoir. Studies have also shown significant associations between monocyte HIV DNA levels with markers of neurodamage. However, qPCR assays using PBMCs are cheaper and available commercially, thus could be beneficial in clinical settings. There is need, however, to standardise DNA extraction, normalisation and limit of detection.

Combination antiretroviral therapy reduces the detection risk of cervical human papilloma virus infection in women living with HIV.

OBJECTIVE: Data on the effect of combination antiretroviral therapy (cART) on cervical human papilloma virus (HPV) infection are both limited and conflicting. We aimed to determine the effect of the initiation of cART for HPV genotype detection on cervical samples in HIV-infected South African women. DESIGN: Prospective cohort study. METHODS: Generalized estimating equation was performed to estimate parameters of mixed-effects logistic regression models of cART on HPV cervical detection risk, adjusting for time-dependent covariates CD4 T-cell count, sexual activity and excision treatment. Ratio of odds ratios (ORs) was computed to compare the pooled cART effect on lower vs. high-risk HPV genotype groups, to the effect of cART on the risk of HPV-16 detection. RESULTS: Of the 300 patients, 204 (68%) were commenced on ART during follow-up, as they met the criteria for cART initiation. cART significantly reduced the risk for detection of HPV by 77% [OR 0.23, 95% confidence interval (CI) 0.15-0.37]. cART significantly reduced the risk of HPV-16 detection (OR 0.50, 95% CI 0.37-0.67). Every month on cART significantly reduced the detection risk of any HPV type by 9% (OR 0.91, 95% CI 0.89-0.94). The protective effect of cART on the detection risk for the low-risk HPV genotype group was significantly less than the protective effect of cART on the detection risk of HPV-16 (ratio of ORs 1.35, 95% CI 1.22-1.50). CONCLUSION: cART significantly reduced cervical HPV infection. This effect was dependent on the duration of exposure to cART and is the mechanism by which cART may improve the outcome of dysplasia in HIV-infected women.

Sequencing and phylogenetic analysis of near full-length HIV-1 subtypes A, B, G and unique recombinant AC and AD viral strains identified in South Africa.

By the end of 2012, more than 6.1 million people were infected with HIV-1 in South Africa. Subtype C was responsible for the majority of these infections and more than 300 near full-length genomes (NFLGs) have been published. Currently very few non-subtype C isolates have been identified and characterized within the country, particularly full genome non-C isolates. Seven patients from the Tygerberg Virology (TV) cohort were previously identified as possible non-C subtypes and were selected for further analyses. RNA was isolated from five individuals (TV047, TV096, TV101, TV218, and TV546) and DNA from TV016 and TV1057. The NFLGs of these samples were amplified in overlapping fragments and sequenced. Online subtyping tools REGA version 3 and jpHMM were used to screen for subtypes and recombinants. Maximum likelihood (ML) phylogenetic analysis (phyML) was used to infer subtypes and SimPlot was used to confirm possible intersubtype recombinants. We identified three subtype B (TV016, TV047, and TV1057) isolates, one subtype A1 (TV096), one subtype G (TV546), one unique AD (TV101), and one unique AC (TV218) recombinant form. This is the first NFLG of subtype G that has been described in South Africa. The subtype B sequences described also increased the NFLG subtype B sequences in Africa from three to six. There is a need for more NFLG sequences, as partial HIV-1 sequences may underrepresent viral recombinant forms. It is also necessary to continue monitoring the evolution and spread of HIV-1 in South Africa, because understanding viral diversity may play an important role in HIV-1 prevention strategies.

Construction of a high titer infectious HIV-1 subtype C proviral clone from South Africa.

The Human Immunodeficiency Virus type 1 (HIV-1) subtype C is currently the predominant subtype worldwide. Cell culture studies of Sub-Saharan African subtype C proviral plasmids are hampered by the low replication capacity of the resulting viruses, although viral loads in subtype C infected patients are as high as those from patients with subtype B. Here, we describe the sequencing and construction of a new HIV-1 subtype C proviral clone (pZAC), replicating more than one order of magnitude better than the previous subtype C plasmids. We identify the env-region for being the determinant for the higher viral titers and the pZAC Env to be M-tropic. This higher replication capacity does not lead to a higher cytotoxicity compared to previously described subtype C viruses. In addition, the pZAC Vpu is also shown to be able to down-regulate CD4, but fails to fully counteract CD317.

HIV drug resistance (HIVDR) in antiretroviral therapy-naïve patients in Tanzania not eligible for WHO threshold HIVDR survey is dramatically high.

BACKGROUND: The World Health Organization (WHO) has recommended guidelines for a HIV drug resistance (HIVDR) survey for resource-limited countries. Eligibility criteria for patients include age below 25 years in order to focus on the prevalence of transmitted HIVDR (tHIVDR) in newly-infected individuals. Most of the participating sites across Africa have so far reported tHIVDR prevalences of below 5%. In this study we investigated whether the rate of HIVDR in patients <25 years is representative for HIVDR in the rest of the therapy-naïve population. METHODS AND FINDINGS: HIVDR was determined in 88 sequentially enrolled ART-naïve patients from Mwanza, Tanzania (mean age 35.4 years). Twenty patients were aged <25 years and 68 patients were aged 25-63 years. The frequency of HIVDR in the study population was 14.8% (95%; CI 0.072-0.223) and independent of NVP-resistance induced by prevention of mother-to-child transmission programs. Patients >25 years had a significantly higher HIVDR frequency than younger patients (19.1%; 95% CI 0.095-0.28) versus 0%, P = 0.0344). In 2 out of the 16 patients with HIVDR we found traces of antiretrovirals (ARVs) in plasma. CONCLUSIONS: ART-naïve patients aged over 25 years exhibited significantly higher HIVDR than younger patients. Detection of traces of ARVs in individuals with HIVDR suggests that besides transmission, undisclosed misuse of ARVs may constitute a significant factor in the generation of the observed high HIVDR rate. The current WHO tHIVDR survey that is solely focused on the transmission of HIVDR and that excludes patients over 25 years of age may therefore result in substantial underestimation of the prevalence of HIVDR in the therapy-naïve population. Similar studies should be performed also in other areas to test whether the so far reported optimistic picture of low HIVDR prevalence in young individuals is really representative for the rest of the ART-naïve HIV-infected population.

Phylogenetic diversity and low level antiretroviral resistance mutations in HIV type 1 treatment-naive patients from Cape Town, South Africa.

We analyzed the HIV-1 pol gene from patients in Cape Town to determine the genetic diversity of HIV-1 in the region and to assess the baseline HIV-1 resistance level of treatment-naive patients. Plasma was collected prior to the national antiretroviral therapy (ART) program. RNA was extracted, followed by RT-PCR and automated DNA sequencing of the viral protease (PR) and reverse transcriptase (RT) coding region. Genotyping was done through phylogenetic analysis. The sequences were inspected for resistance-associated mutations against PR and RT inhibitors. A total of 140 pol sequences were analyzed, of which 133 (95%) belong to HIV-1 subtype C, five (3.6%) were subtype B, and one each was subtype G and CRF02_AG. Five sequences (3.6%) had resistance-associated mutations. These include three (2.1%) NNRTI mutations. With the progression of the national ART program, it is important to monitor the resistance profile of naive and treatment-experienced patients.

Molecular analysis of HIV type 1 vif sequences from Cape Town, South Africa.

South Africa has the highest number of HIV-1-infected individuals in the world, with HIV-1 subtype C prevailing. However, HIV-1 subtype C accessory genes are rarely characterized in the country. These genes are important for establishing viral pathogenesis. The Vif protein has been shown to counteract the antiretroviral activity of APOBEC3G/F cytidine deaminases. In this study an additional 50 HIV-1 vif sequences are characterized. These include 48 HIV-1 subtype C and 2 HIV-1 subtype B sequences. Highly conserved HIV-1 subtype C motifs are outlined. The previously identified RLRR (90-93) motif does not seem to be conserved among our newly analyzed sequences. Conserved motifs can be useful for developing new vaccine strategies or antiretroviral drugs.

Complete genome sequencing of a non-syncytium-inducing HIV type 1 subtype D strain from Cape Town, South Africa.

The fast growing HIV-1 epidemic in South Africa is mainly caused by HIV-1 group M subtype C, spreading via heterosexual transmission. In South Africa HIV-1 subtype B and D viruses were responsible for the initial epidemic during the 1980s, primarily in the homosexual population. This study describes the full-length PCR amplification and sequencing of an HIV-1 subtype D strain recovered from plasma from a sample taken during 1990. This is only the second full-length non-syncytium-inducing (NSI) subtype D strain described. Although restricted, the subtype D strain is still being detected in the South African population.