Despite efficient combination of the antiretroviral therapy (cART), which significantly decreased mortality and morbidity of HIV-1 infection, a definitive HIV cure has not been achieved. Hidden HIV-1 ...in cellular and anatomic reservoirs is the major hurdle toward a functional cure. Microglial cells, the Central Nervous system (CNS) resident macrophages, are one of the major cellular reservoirs of latent HIV-1. These cells are believed to be involved in the emergence of drugs resistance and reseeding peripheral tissues. Moreover, these long-life reservoirs are also involved in the development of HIV-1-associated neurocognitive diseases (HAND). Clearing these infected cells from the brain is therefore crucial to achieve a cure. However, many characteristics of microglial cells and the CNS hinder the eradication of these brain reservoirs. Better understandings of the specific molecular mechanisms of HIV-1 latency in microglial cells should help to design new molecules and new strategies preventing HAND and achieving HIV cure. Moreover, new strategies are needed to circumvent the limitations associated to anatomical sanctuaries with barriers such as the blood brain barrier (BBB) that reduce the access of drugs.
One of the most explored therapeutic approaches aimed at eradicating HIV-1 reservoirs is the "shock and kill" strategy which is based on HIV-1 reactivation in latently-infected cells ("shock" phase) ...while maintaining antiretroviral therapy (ART) in order to prevent spreading of the infection by the neosynthesized virus. This kind of strategy allows for the "kill" phase, during which latently-infected cells die from viral cytopathic effects or from host cytolytic effector mechanisms following viral reactivation. Several latency reversing agents (LRAs) with distinct mechanistic classes have been characterized to reactivate HIV-1 viral gene expression. Some LRAs have been tested in terms of their potential to purge latent HIV-1
in clinical trials, showing that reversing HIV-1 latency is possible. However, LRAs alone have failed to reduce the size of the viral reservoirs. Together with the inability of the immune system to clear the LRA-activated reservoirs and the lack of specificity of these LRAs, the heterogeneity of the reservoirs largely contributes to the limited success of clinical trials using LRAs. Indeed, HIV-1 latency is established in numerous cell types that are characterized by distinct phenotypes and metabolic properties, and these are influenced by patient history. Hence, the silencing mechanisms of HIV-1 gene expression in these cellular and tissue reservoirs need to be better understood to rationally improve this cure strategy and hopefully reach clinical success.
Abstract
Background
We aimed to describe the clinical presentation of individuals presenting with prolonged recovery from coronavirus disease 2019 (COVID-19), known as long COVID.
Methods
This was an ...analysis within a multicenter, prospective cohort study of individuals with a confirmed diagnosis of COVID-19 and persistent symptoms >4 weeks from onset of acute symptoms. We performed a multiple correspondence analysis (MCA) on the most common self-reported symptoms and hierarchical clustering on the results of the MCA to identify symptom clusters.
Results
Two hundred thirty-three individuals were included in the analysis; the median age of the cohort was 43 (interquartile range IQR, 36–54) years, 74% were women, and 77.3% reported a mild initial illness. MCA and hierarchical clustering revealed 3 clusters. Cluster 1 had predominantly pain symptoms with a higher proportion of joint pain, myalgia, and headache; cluster 2 had a preponderance of cardiovascular symptoms with prominent chest pain, shortness of breath, and palpitations; and cluster 3 had significantly fewer symptoms than the other clusters (2 IQR, 2–3 symptoms per individual in cluster 3 vs 6 IQR, 5–7 and 4 IQR, 3–5 in clusters 1 and 2, respectively; P < .001). Clusters 1 and 2 had greater functional impairment, demonstrated by significantly longer work absence, higher dyspnea scores, and lower scores in SF-36 domains of general health, physical functioning, and role limitation due to physical functioning and social functioning.
Conclusions
Clusters of symptoms are evident in long COVID patients that are associated with functional impairments and may point to distinct underlying pathophysiologic mechanisms of disease.
Abstract
SARS-CoV-2 neutralising antibodies provide protection against COVID-19. Evidence from early vaccine trials suggested binding antibody thresholds could serve as surrogate markers of ...neutralising capacity, but whether these thresholds predict sufficient neutralising capacity against variants of concern (VOCs), and whether this is impacted by vaccine or infection history remains unclear. Here we analyse individuals recovered from, vaccinated or with hybrid immunity against SARS-CoV-2. An NT50 ≥ 100 IU confers protection in vaccine trials, however, as VOC induce a reduction in NT50, we use NT50 ≥ 1000 IU as a cut off for WT NT50 that would retain neutralisation against VOC. In unvaccinated convalescent participants, a receptor binding domain (RBD) IgG of 456 BAU/mL predicts an NT50 against WT of 1000 IU with an accuracy of 80% (95%CI 73–86%). This threshold maintains accuracy in determining loss of protective immunity against VOC in two vaccinated cohorts. It predicts an NT50 < 100 IU against Beta with an accuracy of 80% (95%CI 67–89%) in 2 vaccine dose recipients. In booster vaccine recipients with a history of COVID-19 (hybrid immunity), accuracy is 87% (95%CI 77–94%) in determining an NT50 of <100 IU against BA.5. This analysis provides a discrete threshold that could be used in future clinical studies.
Quantifying neutralising capacity of circulating SARS-COV-2 antibodies is critical in evaluating protective humoral immune responses generated post-infection/post-vaccination. Here we describe a ...novel medium-throughput flow cytometry-based micro-neutralisation test to evaluate Neutralising Antibody (NAb) responses against live SARS-CoV-2 Wild Type and Variants of Concern (VOC) in convalescent/vaccinated populations. Flow Cytometry-Based Micro-Neutralisation Test (Micro-NT) was performed in 96-well plates using clinical isolates WT-B, WT-B.1.177.18 and/or VOCs Beta and Omicron. Plasma samples (All Ireland Infectious Diseases (AIID) Cohort) were serially diluted (8 points, half-log) from 1:20 and pre-incubated with SARS-CoV-2 (1h, 37°C). Virus-plasma mixture were added onto Vero E6 or Vero E6/TMPRSS2 cells for 18h. Percentage infected cells was analysed by automated flow cytometry following trypsinisation, fixation and SARS-CoV-2 Nucleoprotein intracellular staining. Half-maximal Neutralisation Titres (NT50) were determined using non-linear regression. Our assay was compared to Plaque Reduction Neutralisation Test (PRNT) and validated against the First WHO International Standard for anti-SARS-CoV-2 immunoglobulin. Both Micro-NT and PRNT achieved comparable NT50 values. Further validation showed adequate correlation with PRNT using a panel of secondary standards of clinical convalescent and vaccinated plasma samples. We found the assay to be reproducible through measuring both repeatability and intermediate precision. Screening 190 convalescent samples and 11 COVID-19 naive controls (AIID cohort) we demonstrated that Micro-NT has broad dynamic range differentiating NT50s <1/20 to >1/5000. We could also characterise immune-escape VOC Beta and Omicron BA.5, achieving fold-reductions in neutralising capacity similar to those published. Our flow cytometry-based Micro-NT is a robust and reliable assay to quantify NAb titres, and has been selected as an endpoint in clinical trials.
The reported prevalence of cognitive impairment (CI) varies widely in cohorts of people living with HIV (PLWH); this may partly be due to the use of different diagnostic criteria. Agreement between ...diagnostic criteria of CI, the optimal definition to use, and associations with patient-reported cognitive symptoms have not been fully investigated.
Two hundred ninety PLWH aged >50 years and 97 matched negative controls completed a detailed assessment of cognitive function and three questions regarding cognitive symptoms. Age- and education-adjusted test scores (T-scores) determined if subjects met the following definitions of CI: Frascati, global deficit score (GDS) and the multivariate normative comparison (MNC) method.
PLWH were more likely than controls to meet each definition of CI (ORs were 2.17, 3.12 and 3.64 for Frascati, GDS and MNC, respectively). Agreement of MNC with Frascati and GDS was moderate (Cohen's k = 0.42 and 0.48, respectively), whereas that between Frascati and GDS was good (k = 0.74). A significant association was found between all the three criteria and reporting of memory loss but not with attention and reasoning problems. The 41 (14 %) PLWH meeting all the three criteria had the lowest median global T-score (36.9) and highest rate of symptom reporting (42 %).
Different CI criteria show fair diagnostic agreement, likely reflecting their ability to exclude CI in the same group of individuals. Given the lower overall cognitive performance and higher rates of symptom reporting in those meeting all three criteria of CI, further work assessing this as a definition of CI in PLWH is justified.
Although low bone mineral density (BMD) is prevalent in HIV, changes in BMD over time remain unclear. We aimed to compare rates of, and factors associated with, BMD change between HIV-positive and ...HIV-negative patients.
In a prospective, 3-year cohort, HIV-positive and HIV-negative patients provided annual demographic and clinical data, fasting bloods, and dual x-ray absorptiometry. Using longitudinal mixed models we compared and determined predictors of rate of change in BMD.
Of 384 study participants (45.8% HIV positive), 120 contributed two and 264 contributed three BMD measurements. Those with HIV were younger median interquartile range 39 (34-46) vs. 43 (35-50) years; P = 0.04, more often men (61 vs. 46%; P = 0.003), and less likely Caucasian (61 vs. 82%; P < 0.001). Although BMD was lower in those with HIV, BMD declined in both groups, with nonsignificant between-group difference in rate of BMD change over time. Within the HIV group, starting antiretroviral therapy (ART) within 3 months of enrolment was associated with greater BMD decline at all anatomical sites (all P < 0.001). Age more than 30 years, Caucasian ethnicity, and not being on ART during follow-up were associated with greater decline and higher parathyroid hormone associated with a smaller decline in BMD at the femoral neck. We found no association between BMD change and exposure to tenofovir disoproxil fumarate or protease inhibitors.
We observed no difference in rate of BMD decline regardless of HIV status and in HIV-positive patient, having started ART within the previous 3 months was the only factor associated with greater BMD decline at all three sites.
Increased prevalence of low bone mineral density (BMD) and increased fracture incidence are observed in persons living with HIV (PLWH). The trabecular bone score (TBS) is a novel index of bone ...microarchitecture which improves fracture prediction independent of BMD.
The HIV UPBEAT study is a single centre, prospective cohort study that enrolled subjects with and without HIV from similar sociodemographic backgrounds for annual assessments of bone health. TBS was derived from lumbar spine (LS) dual-energy X-ray absorptiometry images. Univariate and multivariable linear regression was used to assess relationships between baseline TBS, BMD, sociodemographic and clinical factors.
463 subjects (201 HIV positive) were included; PLWH were younger and more likely male, of non-African ethnicity and current smokers. HIV was associated with a mean reduction of 0.037 -0.060, -0.013 (p = 0.002) in TBS. Lower TBS was also associated with male gender, non-African ethnicity, current smoking status and lower LS BMD. HIV remained associated with lower TBS after adjustment for LS BMD, age, gender and ethnicity. However, adjustment for current smoking significantly attenuated the association between HIV and TBS, with further adjustment for higher bone turnover markers largely explaining any residual association. Among the sub-group of PLWH, exposure to protease inhibitors and lower nadir CD4+ T-cell counts were both predictors of lower TBS.
PLWH have lower TBS independent of LS BMD. However, this is largely explained by higher current smoking rates and higher bone turnover in those with HIV. Exposure to PI, but not tenofovir disproxil fumarate, also contributed to lower TBS in those with HIV.
We investigate the association of widespread pain with sleep quality among people with HIV and HIV-negative controls.
UK-based cohort.
Pain information was collected through a pain mannikin ...identifying affected body sites; pain was classified as widespread if pain was reported in ≥4 of 5 body regions and in ≥7 of 15 body sites, and as regional otherwise. Sleep was assessed a median of 3.2 years later through 7-night actigraphy and through self-reported assessments of sleep quality. Chi-squared tests, Kruskal-Wallis tests, and linear/logistic regression considered associations between pain extent and sleep quality.
Of the 414 participants, 74 (17.9%) reported widespread and 189 (45.7%) regional pain. Although there were few clear associations between actigraphy outcomes and pain extent, those with widespread and regional pain consistently reported poorer sleep quality on all self-reported measures than those with no pain. Median (interquartile range) insomnia severity index and Patient-reported Outcomes Measurement Information System (PROMIS) for sleep disturbance and sleep-related impairment scores were 12 (7-16), 55.3 (48.0-58.9), and 57.2 (48.9-61.3), respectively, for those with widespread pain, 8 (4-13), 51.2 (45.5-58.3), and 50.3 (43.6-56.1) for those with regional pain, and 5 (2-9), 47.9 (42.9-54.3), and 45.5 (41.4-50.3) for those with no pain (all P values 0.0001). Associations remained strong after adjustment for HIV status and other confounders, and were reduced but remained significant, after adjustment for depressive symptoms.
Widespread pain was not associated with objective measures of sleep but was strongly associated with self-reported assessments of sleep quality in people with HIV.
Non-communicable diseases (NCDs) are increased amongst people living with HIV (PLWH) and are driven by persistent immune activation. The role of socioeconomic status (SES) in immune activation ...amongst PLWH is unknown, especially in low-income sub-Saharan Africa (SSA), where such impacts may be particularly severe.
We recruited Malawian adults with CD4<100 cells/ul two weeks after starting ART in the REALITY trial (NCT01825031), as well as volunteers without HIV infection. Clinical assessment, socioeconomic evaluation, blood draw for immune activation markers and carotid femoral pulse wave velocity (cfPWV) were carried out at 2- and 42-weeks post-ART initiation. Socioeconomic risk factors for immune activation and arterial stiffness were assessed using linear regression models.
Of 279 PLWH, the median (IQR) age was 36 (31-43) years and 122 (44%) were female. Activated CD8 T-cells increased from 70% amongst those with no education to 88% amongst those with a tertiary education (p = 0.002); and from 71% amongst those earning less than 10 USD/month to 87% amongst those earning between 100-150 USD/month (p = 0.0001). Arterial stiffness was also associated with higher SES (car ownership p = 0.003, television ownership p = 0.012 and electricity access p = 0.029). Conversely, intermediate monocytes were higher amongst those with no education compared to a tertiary education (12.6% versus 7.3%; p = 0.01) and trended towards being higher amongst those earning less than 10 USD/month compared to 100-150 USD/month (10.5% versus 8.0%; p = 0.08). Water kiosk use showed a protective association against T cell activation (p = 0.007), as well as endothelial damage (MIP1β, sICAM1 and sVCAM1 p = 0.047, 0.026 and 0.031 respectively).
Socioeconomic risk factors for persistent inflammation amongst PLWH in SSA differ depending on the type of inflammatory pathway. Understanding these pathways and their socioeconomic drivers will help identify those at risk and target interventions for NCDs. Future studies assessing drivers of inflammation in HIV should include an SES assessment.
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