ART in HIV-Positive Persons With Low Pretreatment Viremia: Results From the START Trial

The relationship between HIV-1 neuroinflammation, neurocognitive impairment and encephalitis pathology: A systematic review of studies investigating post-mortem brain tissue

The activities of HIV-1 in the central nervous system (CNS) are responsible for a dysregulated neuroinflammatory response and the subsequent development of HIV-associated neurocognitive disorders (HAND). The use of post-mortem human brain tissue is pivotal for studying the neuroimmune mechanisms of CNS HIV infection. To date, numerous studies have investigated HIV-1-induced neuroinflammation in post-mortem brain tissue. However, from the commonly investigated studies in this line of research, it is not clear which neuroinflammatory markers are consistently associated with HIV neurocognitive impairment (NCI) and neuropathology (i.e., HIV-encephalitis, HIVE). Therefore, we conducted a systematic review of the association between neuroinflammation and NCI/HIVE from studies investigating post-mortem brain tissue. Our aim was to synthesise the published data to date to provide commentary on the most noteworthy markers that are associated with NCI/HIVE. PubMed, Scopus, and Web of Science databases were searched using a search protocol designed specifically for this study. Sixty-one studies were included that investigated the levels of inflammatory markers based on their gene and protein expression in association with NCI/HIVE. The findings revealed that the (1) transcript expressions of IL-1β and TNF-α were consistently associated with NCI/HIVE, whereas CCL2 and IL-6 were commonly not associated with NCI/HIVE, (2) protein expressions of CD14, CD16, CD68, Iba-1, IL-1β and TNF-α were consistently associated with NCI/HIVE, while CD45, GFAP, HLA-DR, IL-1 and IL-6 were commonly not associated with NCI/HIVE, and (3) gene and protein expressions of CNS IL-1β and TNF-α were consistently associated with NCI/HIVE, while IL-6 was consistently not associated with NCI/HIVE. These markers highlight the commonly investigated markers in this line of research and elucidates the neuroinflammatory mechanisms in the HIV-1 brain that are involved in the pathophysiology of NCI/HIVE. These markers and related pathways should be investigated for the development of improved diagnostics, prognostics, and therapeutics of HAND.

Selected inflammatory and coagulation biomarkers pre-viral suppression in people with human immunodeficiency virus (HIV) infection without overt cardiovascular disease: Is there a need to redefine reference indices?

BACKGROUND

Human immunodeficiency virus (HIV) infection is prevalent in Africa and causes morbidity and mortality despite antiretroviral therapy (ART). Non-communicable complications of HIV infection include cardiovascular disease (CVD) with thromboses throughout the vascular tree. Ongoing inflammation and endothelial dysfunction in people living with HIV (PLWH) probably contribute significantly to HIV-related CVD.

OBJECTIVES

A systematic review was conducted to inform interpretation of 5 biomarkers commonly measured in PLWH namely interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α), D-dimers, and soluble intracellular and vascular adhesion molecules-1 (sICAM-1 and sVCAM-1) to attempt to define a range for these values in ART naïve PLWH without overt CVD or additional comorbid diseases.

METHODS

A systematic search was conducted for all studies documenting the levels of the above biomarkers in ART naïve PLWH published on the PubMed database from 1994 to 2020.

RESULTS

The number of publications that reported medians above the assay values was: 4/15 for D-dimer; 0/5 for TNF-α, 8/16 for IL-6, 3/6 for sVCAM-1, and 4/5 for sICAM-1.

CONCLUSION

The clinical utility of biomarkers is reduced by the lack of standardisation of the measurement of these parameters, absence of normal reference indices and the lack of uniformity of study protocols in different research centres. This review supports the ongoing use of D-dimers to predict thrombotic and bleeding events in PLWH since the weighted averages across study assays suggest that the median levels do not exceed the reference range. The role of inflammatory cytokine monitoring and measurement of endothelial adhesion markers is less clear.

Non-AIDS-Defining Events in Human Immunodeficiency Virus Controllers Versus Antiretroviral Therapy-Controlled Patients: A Cohort Collaboration From the French National Agency for Research on AIDS CO21 (CODEX) and CO06 (PRIMO) Cohorts

Background

Low-grade chronic inflammation may persist in spontaneous human immunodeficiency virus controllers (HICs), leading to non-AIDS-defining events (nADEs).

Methods

Two hundred twenty-seven antiretroviral therapy (ART)-naive HICs (known human immunodeficiency virus type 1 [HIV-1] infection ≥5 years and at least 5 consecutive viral loads [VLs] <400 HIV RNA copies/mL) were compared with 328 patients who initiated ART ≤1 month after primary HIV infection diagnosis and had undetectable VL within 12 months following ART initiation for at least 5 years. Incidence rates of first nADEs were compared between HICs and ART-treated patients. Determinants of nADEs were assessed by using Cox regression models.

Results

All-cause nADEs incidence rates were 7.8 (95% confidence interval [CI], 5.9-9.6) and 5.2 (95% CI, 3.9-6.4) per 100 person-months among HICs and ART patients, respectively (incidence rate ratio [IRR], 1.5 [95% CI, 1.1-2.2]; adjusted IRR, 1.93 [95% CI, 1.16-3.20]). After adjustment for the cohort, demographic, and immunological characteristics, the only other factor associated with all-cause nADE occurrence was age ≥43 (vs <43) years at the beginning of viral control (IRR, 1.69 [95% CI, 1.11-2.56]). The most frequent events observed in the 2 cohorts were non-AIDS-related benign infections (54.6% and 32.9% of all nADEs, respectively, for HICs and ART patients). No differences in cardiovascular or psychiatric events were observed.

Conclusions

HICs experienced 2 times more nADEs than virologically suppressed patients on ART, mainly non-AIDS-related benign infections. Older age was associated with nADE occurrence, independent of immune or virologic parameters. These results do not argue in favor of expanding the ART indication for HICs but rather a case-by-case approach considering clinical outcomes such as nADEs besides immune activation.

Thrombotic thrombocytopenic purpura (TTP) in Human immunodeficiency virus (HIV) infected patients: New twists on an old disease

OBJECTIVE

Investigate the presence of inflammation, endothelial dysfunction and complement activation in patients with HIV-associated thrombotic thrombocytopenic purpura (HIV-TTP) to support the hypothesis that these processes probably contribute to the development of this thrombotic microangiopathy.

DESIGN

A prospective, investigational cohort study of 35 consecutive patients diagnosed with HIV-associated TTP presenting to three academic, tertiary care hospitals in Johannesburg, South Africa over 2 years.

METHODS

The patients with HIV-TTP received therapeutic plasma therapy and supportive treatment. Demographic data, the results of routine investigations and patient outcomes were recorded. Peripheral blood samples were collected prior to and on completion of plasma therapy and the following additional parameters were assessed at both time points: activity of the von Willebrand factor (VWF) cleaving protease, a-disintegrin-and-metalloproteinase-with-thrombospondin-motifs 13 (ADAMTS-13) and the presence of ADAMTS-13 autoantibodies, levels of pro-inflammatory cytokines, interleukin-6 and tumour necrosis factor-alpha, and two endothelial cell adhesion molecules. Complement activation was assessed by sequential measurement of C3 and C4 as well as levels of the complement inhibitor, factor H.

RESULTS

The inflammatory and endothelial activation markers were significantly (P < 0.001) elevated in the cohort of patients prior to plasma therapy compared with levels on discharge. Complement was activated and normalized with therapy. The ADAMTS-13 levels were reduced with significant auto-antibodies to this protease at presentation.

CONCLUSION

Inflammation in HIV mediates endothelial damage and complement activation. This study proposes that these processes are probably contributory to the development of HIV-TTP, which can therefore be characterized in part as a complementopathy, resembling TTP-like syndrome.

Increased biomarkers of cardiovascular risk in HIV-1 viremic controllers and low persistent inflammation in elite controllers and art-suppressed individuals

HIV controllers (HICs) are models of HIV functional cure, although some studies have shown persistent inflammation and increased rates of atherosclerosis in HICs. Since immune activation/inflammation contributes to the pathogenesis of cardiovascular diseases (CVD), we evaluated clinical data and inflammation markers in HIV-1 viremic controllers (VC), elite controllers (EC), and control groups (HIV positive individuals with virological suppression by antiretroviral therapy—cART; HIV negative individuals—HIVneg) to assess whether they presented elevated levels of inflammation markers also associated with CVD. We observed the highest frequencies of activated CD8⁺ T cells in VCs, while EC and cART groups presented similar but slightly altered frequencies of this marker when compared to the HIVneg group. Regarding platelet activation, both HICs groups presented higher expression of P-selectin in platelets when compared to control groups. Monocyte subset analyses revealed lower frequencies of classical monocytes and increased frequencies of non-classical and intermediate monocytes among cART individuals and in EC when compared to HIV negative individuals, but none of the differences were significant. For VC, however, significant decreases in frequencies of classical monocytes and increases in the frequency of intermediate monocytes were observed in comparison to HIV negative individuals. The frequency of monocytes expressing tissue factor was similar among the groups on all subsets. In terms of plasma markers, VC had higher levels of many inflammatory markers, while EC had higher levels of VCAM-1 and ICAM-1 compared to control groups. Our data showed that VCs display increased levels of inflammation markers that have been associated with CVD risk. Meanwhile, ECs show signals of lower but persistent inflammation, comparable to the cART group, indicating the potential benefits of alternative therapies to decrease inflammation in this group.

Coronavirus disease 2019 (COVID-19) outcomes in HIV/AIDS patients: a systematic review

OBJECTIVES

The aim of the study was to systematically review current studies reporting on clinical outcomes in people living with HIV (PLHIV) infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

We conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. A comprehensive literature search was conducted in Global Health, SCOPUS, Medline and EMBASE using pertinent key words and Medical Subject Headings (MeSH) terms relating to coronavirus disease 2019 (COVID-19) and HIV. A narrative synthesis was undertaken. Articles are summarized in relevant sections.

RESULTS

Two hundred and eighty-five articles were identified after duplicates had been removed. After screening, eight studies were analysed, totalling 70 HIV-infected patients (57 without AIDS and 13 with AIDS). Three themes were identified: (1) controlled HIV infection does not appear to result in poorer COVID-19 outcomes, (2) more data are needed to determine COVID-19 outcomes in patients with AIDS and (3) HIV-infected patients presenting with COVID-19 symptoms should be investigated for superinfections.

CONCLUSIONS

Our findings suggest that PLHIV with well-controlled disease are not at risk of poorer COVID-19 disease outcomes than the general population. It is not clear whether those with poorly controlled HIV disease and AIDS have poorer outcomes. Superimposed bacterial pneumonia may be a risk factor for more severe COVID-19 but further research is urgently needed to elucidate whether PLHIV are more at risk than the general population.