HIV and fracture: Risk, assessment and intervention

OBJECTIVES

With management of comorbidity in people living with HIV (PLWH) a key component of clinical care, early loss of bone integrity and clinical fracture are recognized as important issues. This review aims to describe the epidemiology of fracture in PLWH, as well as summarizing the relative balance of factors that contribute to fracture. We also aim to describe fracture risk assessment and interventional strategies to modify the risk of fracture in this population.

RESULTS

Data from recent meta-analyses show that PLWH have significantly more fractures than the general population, with men and injecting drug users at higher risk. Modifiable factors that contribute to fracture risk in this cohort include body mass index (BMI), drug use, concurrent medications, frailty, and hepatitis C virus infection. Relating to antiretroviral therapy, current or ever tenofovir exposure has been identified as predictive of fracture but not cumulative use, and a potentially modest protective effect of efavirenz has been observed. Fracture Risk Assessment Tool scores underestimate fracture risk in PLWH with improved accuracy when HIV is considered a cause of secondary osteoporosis and bone mineral density (BMD) included.

CONCLUSION

Early consideration of risk, prompting evaluation of modifiable risk factors, frailty and falls risk with bone density imaging and prompt intervention may avert fracture in PLWH. Guidance on screening and lifestyle modification is available in international guidelines. Bisphosphonates are safe and effective in PLWH, with limited data for other agents.

Associations between host microbiome and inflammation suggest role for host microbiome in driving COVID-19 disease severity

Systemic inflammation and innate immune activation are associated with COVID-19 disease severity. Knowledge gaps remain in the relationships between microbiome, inflammation and COVID-19 disease severity. To better characterise these associations, we performed 16SrDNA analysis of stool samples in COVID-19 subjects to explore diversity and taxanomic composition. We correlated these to host inflammatory profiles, derived from soluble plasma biomarkers measured by bead-based fluorescence and electrochemiluminescence immunoassays. Associations of microbial diversity and inflammatory biomarkers on maximal COVID-19 severity (mild, moderate v severe/critical) was explored using logistic regression and weighted gene correlation network analysis (WGCNA). Of 79 subjects, 58% were male and 88% were Caucasian with 36% experiencing mild disease, 22% moderate disease and 40% critical/severe COVID-19. Hierarchical clustering and principal component analysis (PCo) revealed distinct inflammatory clusters that were found to correlate with 4 modules of microbiome profiles. Modules 3 and 4 were associated with both older age and severe/critical disease outcomes. These modules were enriched in pathogenic and inflammatory bacteria that mapped to a pro-inflammatory biomarker cluster. In contrast, module 1 exhibited enrichment of anti-inflammatory bacteria, was associated with younger age and mild/moderate disease outcomes and mapped to a less-inflamed biomarker cluster. This study provides further insights into links between host microbiome, inflammatory responses to SARS-CoV-2 infection and clinical COVID-19 disease severity, suggesting a role for the microbiome in shaping distinct host inflammatory responses to infection.

Distinct Inflammatory Phenotypes are associated with subclinical and clinical Cardiovascular disease in People living with HIV

Despite inflammation being implicated in cardiovascular disease (CVD) in people with HIV (PWH), considerable heterogeneity within populations of PWH exists. Stratifying CVD risk based on inflammatory phenotype could play an important role. Using principal component analyses and unsupervised hierarchical clustering, we examined 38 biomarkers to identify inflammatory phenotypes in two independent cohorts of PWH. We identified three distinct inflammatory clusters present in both cohorts that associated with altered risk of both subclinical CVD (cohort 1) and prevalent clinical CVD (cohort 2) after adjusting for CVD risk factors. These data support precision medicine approaches to enhance CVD risk assessment in PWH.

Impact of vaccination and variants of concern on long COVID clinical phenotypes

BACKGROUND

Defining patterns of symptoms in long COVID is necessary to advance therapies for this heterogeneous condition. Here we aimed to describe clusters of symptoms in individuals with long COVID and explore the impact of the emergence of variants of concern (VOCs) and vaccination on these clusters.

METHODS

In a prospective, multi centre cohort study, individuals with symptoms persisting > 4 weeks from acute COVID-19 were divided into two groups based on timing of acute infection; pre-Alpha VOC, denoted wild type (WT) group and post-Alpha VOC (incorporating alpha and delta dominant periods) denoted VOC group. We used multiple correspondence analysis (MCA) and hierarchical clustering in the WT and VOC groups to identify symptom clusters. We then used logistic regression to explore factors associated with individual symptoms.

RESULTS

A total of 417 individuals were included in the analysis, 268 in WT and 149 in VOC groups respectively. In both groups MCA identified three similar clusters; a musculoskeletal (MSK) cluster characterised by joint pain and myalgia, a cardiorespiratory cluster and a less symptomatic cluster. Differences in characteristic symptoms were only seen in the cardiorespiratory cluster where a decrease in the frequency of palpitations (10% vs 34% p = 0.008) and an increase in cough (63% vs 17% p < 0.001) in the VOC compared to WT groups was observed. Analysis of the frequency of individual symptoms showed significantly lower frequency of both chest pain (25% vs 39% p = 0.004) and palpitations (12% vs 32% p < 0.001) in the VOC group compared to the WT group. In adjusted analysis being in the VOC group was significantly associated with a lower odds of both chest pain and palpitations, but vaccination was not associated with these symptoms.

CONCLUSION

This study suggests changes in long COVID phenotype in individuals infected later in the pandemic, with less palpitations and chest pain reported. Adjusted analyses suggest that these effects are mediated through introduction of variants rather than an effect from vaccination.

Distinct receptor binding domain IgG thresholds predict protective host immunity across SARS-CoV-2 variants and time

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.

A comparison of transient elastography with acoustic radiation force impulse elastography for the assessment of liver health in patients with chronic hepatitis C: Baseline results from the TRACER study

Background

Liver stiffness measurements can be used to assess liver fibrosis and can be acquired by transient elastography using FibroScan® and with Acoustic Radiation Force Impulse imaging. The study aimed to establish liver stiffness measurement scores using FibroScan® and Acoustic Radiation Force Impulse in a chronic hepatitis C cohort and to explore the correlation and agreement between the scores and the factors influencing agreement.

Methods

Patients had liver stiffness measurements acquired with FibroScan® (right lobe of liver) and Acoustic Radiation Force Impulse (right and left lobe of liver). We used Spearman's correlation to explore the relationship between FibroScan® and Acoustic Radiation Force Impulse scores. A Bland-Altman plot was used to evaluate bias between the mean percentage differences of FibroScan® and Acoustic Radiation Force Impulse scores. Univariable and multivariable analyses were used to assess how factors such as body mass index, age and gender influenced the agreement between liver stiffness measurements.

Results

Bland-Altman showed the average (95% CI) percentage difference between FibroScan® and Acoustic Radiation Force Impulse scores was 27.5% (17.8, 37.2), p  < 0.001. There was a negative correlation between the average and percentage difference of the FibroScan® and Acoustic Radiation Force Impulse scores ( r (95% CI) = -0.41 (-0.57, -0.21), p < 0.001), thus showing that percentage difference gets smaller for greater FibroScan® and Acoustic Radiation Force Impulse scores. Body mass index was the biggest influencing factor on differences between FibroScan® and Acoustic Radiation Force Impulse (r = 0.12 (0.01, 0.23), p = 0.05). Acoustic Radiation Force Impulse scores at segment 5/8 and the left lobe showed good correlation (r (95% CI) = 0.83 (0.75, 0.89), p < 0.001).

Conclusion

FibroScan® and Acoustic Radiation Force Impulse had similar predictive values for the assessment of liver stiffness in patients with chronic hepatitis C infection; however, the level of agreement varied across lower and higher scores.

Post-COVID care delivery: The experience from an Irish tertiary centre's post-COVID clinic

BACKGROUND

The long-term effects of SARS-CoV-2 infection and optimal follow-up approach are not well-recognised. Here we describe the implementation of a post-COVID clinic in an Irish tertiary centre after the first wave of the pandemic. This study describes the characteristics of our patient cohort and the operations and outcomes of the clinic, exploring some of the risk factors for developing post-COVID syndrome and the appropriateness of the triage system employed.

METHODS

All SARS-CoV-2 positive patients from March 10th to June 14th 2020 were telephone-triaged as red, amber or green based on ongoing symptoms with clinic appointments scheduled accordingly. All clinic visits were face-to-face with the infectious diseases medical team and a proforma for each patient was completed. Data were collected retrospectively by reviewing the proformas and the electronic medical record (EMR).

RESULTS

311 patients attended the clinic. Median time from illness to clinic appointment was 95 days (IQR 77-105.5). 204 patients (66%) were female, 192 (62%) were hospital staff, and the median age was 43 years (IQR 31-53). 138 patients (44%) had required hospital admission. At their first clinic visit 219 patients (70%) had ongoing symptoms. A further appointment was made for 62 patients (20%). 34 patients (11%) were discussed at an MDT meeting, and 55 (18%) were referred onward to a specialist service. 85% of those triaged green, 73% of those triaged amber, and 39% of those triaged red did not receive further follow up after one clinic visit. Patients were more likely to require follow up with reported dyspnoea (OR 5.6; 95% CI 2.8-11.3; p <0.001), cough (OR 3.0; 95% CI 1.1-8.4, p = 0.04), and palpitations (OR 3.6; 95% CI 1.0-12.3; p = 0.04). Female sex was associated with increased odds of a higher triage category (OR 1.8; 95% CI 1.08 to 3.20; p = 0.02), as was requiring admission to hospital (OR 4.0; 95% CI 2.34 to 6.90; p < 0.001).

CONCLUSION

The long-term effects of COVID-19 are significant with 70% of our cohort experiencing persistent symptoms. Persistent dyspnoea, cough and palpitations were associated with increased need for follow up. This study also suggests that a traffic light telephone-triage service followed by a face-to-face medical-led clinic could be an effective way of identifying patients who require further management.

Dysregulated early transcriptional signatures linked to mast cell and interferon responses are implicated in COVID-19 severity

Background

Dysregulated immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are thought to underlie the progression of coronavirus disease 2019 (COVID-19) to severe disease. We sought to determine whether early host immune-related gene expression could predict clinical progression to severe disease.

Methods

We analysed the expression of 579 immunological genes in peripheral blood mononuclear cells taken early after symptom onset using the NanoString nCounter and compared SARS-CoV-2 negative controls with SARS-CoV-2 positive subjects with mild (SARS+ Mild) and Moderate/Severe disease to evaluate disease outcomes. Biobanked plasma samples were also assessed for type I (IFN-α2a and IFN-β), type II (IFN-γ) and type III (IFN-λ1) interferons (IFNs) as well as 10 additional cytokines using multiplex immunoassays.

Results

We identified 19 significantly deregulated genes in 62 SARS-CoV-2 positive subject samples within 5 days of symptom onset and 58 SARS-CoV-2 negative controls and found that type I interferon (IFN) signalling (MX1, IRF7, IFITM1, IFI35, STAT2, IRF4, PML, BST2, STAT1) and genes encoding proinflammatory cytokines (TNF, TNFSF4, PTGS2 and IL1B) were upregulated in both SARS+ groups. Moreover, we found that FCER1, involved in mast cell activation, was upregulated in the SARS+ Mild group but significantly downregulated in the SARS+ Moderate/Severe group. In both SARS+ groups we discovered elevated interferon type I IFN-α2a, type II IFN and type III IFN λ1 plasma levels together with higher IL-10 and IL-6. These results indicate that those with moderate or severe disease are characterised by deficiencies in a mast cell response together with IFN hyper-responsiveness, suggesting that early host antiviral immune responses could be a cause and not a consequence of severe COVID-19.

Conclusions

This study suggests that early host immune responses linking defects in mast cell activation with host interferon responses correlates with more severe outcomes in COVID-19. Further characterisation of this pathway could help inform better treatment for vulnerable individuals.

Performance and validation of an adaptable multiplex assay for detection of serologic response to SARS-CoV-2 infection or vaccination

Measurement of quantitative antibody responses are increasingly important in evaluating the immune response to infection and vaccination. In this study we describe the validation of a quantitative, multiplex serologic assay utilising an electrochemiluminescence platform, which measures IgG against the receptor binding domain (RBD), spike S1 and S2 subunits and nucleocapsid antigens of SARS-CoV-2. The assay displayed a sensitivity ranging from 73 to 91% and specificity from 90 to 96% in detecting previous infection with SARS-CoV-2 depending on antigenic target and time since infection, and this assay highly correlated with commercially available assays. The within-plate coefficient of variation ranged from 3.8-3.9% and the inter-plate coefficient of variation from 11 to 13% for each antigen.

Predictors and Outcomes for COVID-19 Re-Admissions in the Anticipate Cohort

Aims To describe readmissions of hospitalised patients with COVID-19, define predictors of readmission and explore the long term outcomes using the SF-12 score compared to patients who were not readmitted and those not hospitalised. Methods A single centre retrospective in North Inner-City Dublin. Recruitment was done through a COVID follow up clinic. Predictors of readmission and SF-12 scores at two timepoints post follow up at median 3 months and 12 months. Results Seventy (45%) participants were admitted, with a median age of 49.5 years (IQR 41.3-56.9), 36(51%) of whom were female. Unscheduled readmissions at ≤30 days in COVID-19 patients were 9(12.9%) and length of stay was four days (IQR 2-5). Readmissions were due to ongoing symptoms(n=9(64.3%)) or new complications(n=5(35.7%)). Mechanical ventilation and having symptoms of nausea and vomiting on index admission were predictive of readmission. (p=0.002). SF-12 scores at one year of readmitted patients were not different to patients who were never admitted at median one year follow up, p=.089. Conclusions Most readmissions were of short duration. Early follow up of patients post MV or who had nausea and vomiting on index admission should be prioritised. Wellbeing of readmitted patients was not different to those never hospitalised, at one year.

Assessing the impact of COVID-19 at 1 year using the SF-12 questionnaire: Data from the Anticipate longitudinal cohort study

BACKGROUND

Few studies to date have explored HRQoL in long COVID patients.

METHODS

The Anticipate Study is a prospective single centre observational cohort study. Hospitalised and non-hospitalised patients were seen at a dedicated post-Covid clinic at a 2-4 month (Timepoint 1) and 7-14 month follow up (Timepoint 2). The main objectives of this study are to assess the longitudinal impact of COVID-19 in patients using the 12-item Short Form Survey (SF-12) score, a Health Related Quality of Life tool, also to identify predictors of developing Post COVID-19 Syndrome (PoCS). Also, to describe symptomatology and identify predictors of PoCS at 1 year.

RESULTS

155 patients were enrolled, 105(68%) were female aged 43.3 (31-52) years. In total 149(96%) and 94(61%) completed follow up at median 96(76-118) days and 364 (303-398) days. The overall cohort had significantly reduced Physical Composite Score (PCS) of the SF-12 (45.39(10.58) vs 50(10), p=.02). Participants with PoCS had significantly lower scores than those without symptoms at 1 year follow up (37.2(10.4) v 46.1(10.9) p <0.001), and scores for these patients did not improve over the two Timepoints (PCS 34.95(10.5) - 37.2(10.4), p=.22). Fatigue was the most common symptom. Those with five or more symptoms at initial diagnosis had lower PCS and MCS scores at 1 year. Predictors of PoCS at 1-year were lower PCS, and higher baseline heart rate (HR) at clinic review median 3 months after COVID-19.

CONCLUSION

PoCS patients have lower PCS scores during follow-up which did not significantly improve up to a 1-year follow up. Lower PCS scores and higher resting HR can be used in the weeks after COVID-19 can help predict those at risk of PoCS.

Rapid and Laboratory SARS-CoV-2 Antibody Testing in High-Risk Hospital Associated Cohorts of Unknown COVID-19 Exposure, a Validation and Epidemiological Study After the First Wave of the Pandemic

Objective: We aimed to use SARS-CoV-2 antibody tests to assess the asymptomatic seroprevalence of individuals in high-risk hospital cohorts who's previous COVID-19 exposure is unknown; staff, and patients requiring haemodialysis or chemotherapy after the first wave.

Methods: In a single Center, study participants had five SARS-CoV-2 antibody tests done simultaneously; one rapid diagnostic test (RDT) (Superbio Colloidal Gold IgM/IgG), and four laboratory tests (Roche Elecsys® Anti-SARS-CoV-2 IgG [RE], Abbott Architect i2000SR IgG [AAr], Abbott Alinity IgG [AAl], and Abbott Architect IgM CMIA). To determine seroprevalence, only positive test results on laboratory assay were considered true positives.

Results: There were 157 participants, of whom 103 (65.6%) were female with a median age of 50 years (range 19–90). The IgG component of the RDT showed a high number of false positives (n = 18), was inferior to the laboratory assays (p < 0.001 RDT vs. AAl/AAr, p < 0.001 RDT vs. RE), and had reduced specificity (85.5% vs. AAl/AAr, 87.2% vs. RE). Sero-concordance was 97.5% between IgG laboratory assays (RE vs. AAl/AAr). Specificity of the IgM component of the RDT compared to Abbott IgM CMIA was 95.4%. Ten participants had positivity in at least one laboratory assay, seven (9.9%) of which were seen in HCWs. Two (4.1%) hematology/oncology (H/O) patients and a single (2.7%) haemodialysis (HD) were asymptomatically seropositive. Asymptomatic seroprevalence of HCWs compared to patients was not significant (p = 0.105).

Conclusion: HCWs (9.9%) had higher, although non-significant asymptomatic seroprevalence of SARS-CoV-2 antibodies compared to high-risk patients (H/O 4.1%, HD 2.7%). An IgM/IgG rapid diagnostic test was inferior to laboratory assays. Sero-concordance of 97.5% was found between IgG laboratory assays, RE vs. AAl/AAr.

Routine Hematological Parameters May Be Predictors of COVID-19 Severity

To date, coronavirus disease 2019 (COVID-19) has affected over 100 million people globally. COVID-19 can present with a variety of different symptoms leading to manifestation of disease ranging from mild cases to a life-threatening condition requiring critical care-level support. At present, a rapid prediction of disease severity and critical care requirement in COVID-19 patients, in early stages of disease, remains an unmet challenge. Therefore, we assessed whether parameters from a routine clinical hematology workup, at the time of hospital admission, can be valuable predictors of COVID-19 severity and the requirement for critical care. Hematological data from the day of hospital admission (day of positive COVID-19 test) for patients with severe COVID-19 disease (requiring critical care during illness) and patients with non-severe disease (not requiring critical care) were acquired. The data were amalgamated and cleaned and modeling was performed. Using a decision tree model, we demonstrated that routine clinical hematology parameters are important predictors of COVID-19 severity. This proof-of-concept study shows that a combination of activated partial thromboplastin time, white cell count-to-neutrophil ratio, and platelet count can predict subsequent severity of COVID-19 with high sensitivity and specificity (area under ROC 0.9956) at the time of the patient's hospital admission. These data, pending further validation, indicate that a decision tree model with hematological parameters could potentially form the basis for a rapid risk stratification tool that predicts COVID-19 severity in hospitalized patients.

Antibiotic prescribing patterns in patients hospitalized with COVID-19: lessons from the first wave

BACKGROUND

A high proportion of hospitalized patients with COVID-19 receive antibiotics despite evidence to show low levels of true bacterial coinfection.

METHODS

A retrospective cohort study examining antibiotic prescribing patterns of 300 patients sequentially diagnosed with COVID-19. Patients were grouped into 3 sub-cohorts: Group 1 received no antibiotics, Group 2 received antibiotics for microbiologically confirmed infections and Group 3 was empirically treated with antibiotics for pneumonia. The primary aim was to identify factors that influenced prescription and continuation of antibiotics in Group 3. Secondary aims were to examine differences in outcomes between groups.

RESULTS

In total, 292 patients were included (63 Group 1, 35 Group 2, 194 Group 3), median age was 60 years (IQR 44-76) and the majority were ethnically Irish (62%). The median duration of antibiotics was 7 days (IQR 5-10). In Group 3, factors associated with prescription IV antibiotics on admission were raised C-reactive protein (CRP) (P = 0.024), increased age (P = 0.023), higher quick SOFA (P = 0.016) score and fever >37.5 °C (P = 0.011). Factors associated with duration of antibiotic course were duration of hypoxia (P < 0.001) and maximum respiratory support requirement (P = 0.013). Twenty-one patients in Group 3 had one or more antibiotic escalation events, most (n = 139) had no escalation or de-escalation of therapy.

CONCLUSIONS

Duration of hypoxia and need for respiratory support may have acted as surrogate measures of improvement where usual response measures (CRP, neutrophilia, culture clearance) were absent. Continuous review of antibiotic prescriptions should be at the forefront of clinical management of hospitalized patients with COVID-19.

Reasons for Choice of Antiretroviral Regimens in HIV Patients Presenting Late for Initial Treatment in Europe

The choice of an optimal antiretroviral therapy (ART) in naive patients presenting late for initial therapy with advanced HIV infection, that is, with a CD4 cell count <200/μL and/or an AIDS-defining disease (late presenters, LPs), is still a challenge, even for HIV specialists. At present, there is little information on the decision process and selection criteria that physicians must take into account when choosing the presumably optimal initial ART for LPs. This study analyzes reasons for the individual choice of first-line ART in HIV LPs. We conducted a prospective multi-center study to analyze the decision-making process of physicians treating naive HIV patients presenting with a CD4 cell count <200/μL and/or an AIDS-defining condition. Two European HIV treatment centers based in Frankfurt (Germany) and A Coruna (Spain) participated in the study. Physicians documented the reasons that led to their decision for a specific first-line ART regimen. A questionnaire was designed for the study. Decisions of the participating physicians were evaluated. A total of 52 treatment decisions were analyzed. Evaluation of the choice of antiretroviral treatment demonstrated that for the overall group of physicians, simplicity of the regimen was the most important selection criterion in 34.6% of cases. The presence of comorbidities was given as the decisive selection criterion in 26.9%, followed by experience with the chosen drugs in 21.2% of cases. In the group of physicians choosing an integrase strand transfer inhibitor (INSTI)-based regimen for first-line ART, the same selection criteria were identified as in the overall group; 33.3% of clinicians selected an INSTI-based regimen because of its simplicity. The presence of comorbidities was the second most frequent decisive criterion (31.0%), followed by personal experience with the prescribed ART (23.8%). In the protease inhibitor group, simplicity was also the most common selection criterion with 40%. Results of clinical trials were stated as the most important criterion for the selection of ART in 38% of all cases, followed by the expected adherence of the patient (22%). Among the physicians who used a non-nucleoside reverse transcriptase inhibitor-based regimen, patients' desire to have children was the most frequent criterion for selection of ART (60%). An ongoing pregnancy was the second most frequent selection criterion, followed by ART's simplicity (8%). For patients treated with a single-tablet regimen, simplicity of ART was comprehensibly the most important decisive criterion (54.5%). Experience with the chosen drugs was the decisive selection criterion in 24.2%, followed by comorbidities in 18.2% of cases. Physicians' selection of individual ART in patients presenting late for first-line treatment seems to be predominantly dependent on patient-centered factors such as adherence issues as well as the clinical experience of physicians with the prescribed drugs.

COVID-19 induces a hyperactive phenotype in circulating platelets

Coronavirus Disease 2019 (COVID-19), caused by the novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has affected over 30 million globally to date. Although high rates of venous thromboembolism and evidence of COVID-19-induced endothelial dysfunction have been reported, the precise aetiology of the increased thrombotic risk associated with COVID-19 infection remains to be fully elucidated. Therefore, we assessed clinical platelet parameters and circulating platelet activity in patients with severe and nonsevere COVID-19. An assessment of clinical blood parameters in patients with severe COVID-19 disease (requiring intensive care), patients with nonsevere disease (not requiring intensive care), general medical in-patients without COVID-19, and healthy donors was undertaken. Platelet function and activity were also assessed by secretion and specific marker analysis. We demonstrated that routine clinical blood parameters including increased mean platelet volume (MPV) and decreased platelet:neutrophil ratio are associated with disease severity in COVID-19 upon hospitalisation and intensive care unit (ICU) admission. Strikingly, agonist-induced ADP release was 30- to 90-fold higher in COVID-19 patients compared with hospitalised controls and circulating levels of platelet factor 4 (PF4), soluble P-selectin (sP-selectin), and thrombopoietin (TPO) were also significantly elevated in COVID-19. This study shows that distinct differences exist in routine full blood count and other clinical laboratory parameters between patients with severe and nonsevere COVID-19. Moreover, we have determined all COVID-19 patients possess hyperactive circulating platelets. These data suggest abnormal platelet reactivity may contribute to hypercoagulability in COVID-19 and confirms the role that platelets/clotting has in determining the severity of the disease and the complexity of the recovery path.

Antiretroviral treatment outcomes among late HIV presenters initiating treatment with integrase inhibitors or protease inhibitors

OBJECTIVES

The aim of the study was to investigate the efficacy and safety of first-line antiretroviral therapy (ART) with integrase inhibitor (INI) or protease inhibitor (PI)-based regimens in patients with low CD4 cell counts and/or an AIDS-defining disease.

METHODS

We conducted a retrospective, multicentre analysis to investigate discontinuation proportions and virological response in patients with CD4 cell counts < 200 cells/µL and/or AIDS-defining disease when starting first-line ART. Proportions of those discontinuing ART were compared using univariate analysis. Virological response was analysed using the Food & Drug Administration (FDA) snapshot analysis (HIV-1 RNA < 50 HIV-1 RNA copies/mL at week 48).

RESULTS

Two hundred and eighteen late presenters were included in the study: 13.8% were women and 23.8% were of non-European ethnicity, and the mean baseline CD4 count was 91 cells/µL (standard deviation 112 cells/µL). A total of 131 late presenters started on INI- and 87 on PI-based treatment. It was found that 86.1% of patients treated with INIs and 81.1% of patients treated with PIs had a viral load < 50 copies/mL at week 48; proportions of discontinuation because of adverse events were 6.1% in the INI group and 11.5% in the PI group. No significant differences in discontinuation proportions were observed at week 12 or 48 between INI- and PI-based regimens (P = 0.76 and 0.52, respectively). Virological response was equally good in those receiving INIs and those receiving PIs (86.1% vs. 81.1%, respectively; P = 0.36).

CONCLUSIONS

In a European cohort of late presenters starting first-line INI or PI-based ART regimens, there were no significant differences in discontinuation proportions or virological response at week 48.

Interferon lambda rs368234815 ΔG/ΔG is associated with higher CD4+:CD8+ T-cell ratio in treated HIV-1 infection

BACKGROUND

The objectives of this study were to investigate the relationships between polymorphisms at the interferon lambda (IFNL) locus and CD4⁺:CD8⁺ ratio normalisation in people living with HIV (PLWH) on effective antiretroviral therapy (ART); and to examine whether these polymorphisms influence the composition of T lymphocyte compartments in long-term treated HIV-1 infection.

METHODS

A cross-sectional study in PLWH enrolled into the Mater Immunology study. We performed IFNL genotyping on stored samples and evaluated the association of IFNL single-nucleotide polymorphisms (rs368234815 and rs12979860) with CD4⁺:CD8⁺ ratio normalization (> 1) and expanded CD4⁺ and CD8⁺ T-cell subsets; CD45RO⁺CD62L⁺ (central-memory), CD45RO⁺ CD62L^-(effector-memory) and CD45RO^-CD62L⁺ (naïve), using logistic and linear regression models, respectively.

RESULTS

190 ambulatory PLWH recruited to the main study, 143 were included in the analysis (38 had no stored DNA and 9 no T-lymphocyte subpopulation). Of 143 included, the median age (IQR) was 45(39-48) years, 64% were male and 66% were of Caucasian ethnicity. Heterosexual-contact (36%), injecting drug-use (33%) and men who have sex with men (24%) were the most presented HIV-transmission risk groups. The majority of subjects (90.2%) were on ART with 79% of the cohort having an undetectable HIV-RNA (< 40 copies/ml) and the time since ART initiation was 7.5 (3.7-10.4) year. rs368234815 and rs12979860 displayed similar allelic frequencies, with minor alleles ΔG and T representing 39% and 42%, respectively, of circulating alleles. rs368234815 ΔG/ΔG minor homozygotes were significantly associated with increased odds for attaining a normalised CD4⁺:CD8⁺ ratio compared to rs368234815 T/T major homozygotes in PLWH virologically suppressed on effective ART (OR = 3.11; 95% CI [1.01:9.56]). rs368234815 ΔG/ΔG homozygosity was also significantly associated with lower levels of CD4⁺ effector memory T-cells (regression coefficient: - 7.1%, p = 0.04) and CD8⁺ naïve T-cell subsets were significantly higher in HIV-1 mono-infected PLWH with rs368234815 ΔG/ΔG (regression coefficient: + 7.2%, p = 0.04).

CONCLUSIONS

In virally-suppressed, long-term ART-treated PLWH, rs368234815 ΔG/ΔG homozygotes were more likely to have attained normalisation of their CD4⁺:CD8⁺ ratio, displayed lower CD4⁺ effector memory and higher naive CD8⁺ T-cells. Further studies are needed to replicate our findings in other, larger and more diverse cohorts and to determine the impact of IFNL genetic-variation on CD4⁺:CD8⁺ ratio normalisation and clinical outcomes in PLWH.

Impact of switching from zidovudine to tenofovir disoproxil fumarate on bone mineral density and markers of bone metabolism in virologically suppressed HIV-1 infected patients; a substudy of the PREPARE study

CONTEXT

In virologically suppressed, antiretroviral-treated patients, the effect of switching to tenofovir (TDF) on bone biomarkers compared to patients remaining on stable antiretroviral therapy is unknown.

METHODS

We examined bone biomarkers (osteocalcin [OC], procollagen type 1 amino-terminal propeptide, and C-terminal cross-linking telopeptide of type 1 collagen) and bone mineral density (BMD) over 48 weeks in virologically suppressed patients (HIV RNA < 50 copies/ml) randomized to switch to TDF/emtricitabine (FTC) or remain on first-line zidovudine (AZT)/lamivudine (3TC). PTH was also measured. Between-group differences in bone biomarkers and associations between change in bone biomarkers and BMD measures were assessed by Student's t tests, Pearson correlation, and multivariable linear regression, respectively. All data are expressed as mean (SD), unless otherwise specified.

RESULTS

Of 53 subjects (aged 46.0 y; 84.9% male; 75.5% Caucasian), 29 switched to TDF/FTC. There were reductions in total hip and lumbar spine BMD in those switching to TDF/FTC (total hip, TDF/FTC, -1.73 (2.76)% vs AZT/3TC, -0.39 (2.41)%; between-group P = .07; lumbar spine, TDF/FTC, -1.50 (3.49)% vs AZT/3TC, +0.25 (2.82)%; between-group P = .06), but they did not reach statistical significance. Greater declines in lumbar spine BMD correlated with greater increases in OC (r = -0.28; P = .05). The effect of TDF/FTC on bone biomarkers remained significant when adjusted for baseline biomarker levels, gender, and ethnicity. There was no difference in change in PTH levels over 48 weeks between treatment groups (between-group P = .23). All biomarkers increased significantly from weeks 0 to 48 in the switch group, with no significant change in those remaining on AZT/3TC (between-group, all biomarkers, P < .0001).

CONCLUSION

A switch to TDF/FTC compared to remaining on a stable regimen is associated with increases in bone turnover that correlate with reductions in BMD, suggesting that TDF exposure directly affects bone metabolism in vivo.

Increased platelet reactivity in HIV-1-infected patients receiving abacavir-containing antiretroviral therapy

BACKGROUND

Current or recent use of abacavir for treating human immunodeficiency virus type 1 (HIV-1) infection has been associated with increased rates of myocardial infarction (MI). Given the role of platelet aggregation in thrombus formation in MI and the reversible nature of the abacavir association, we hypothesized that patients treated with abacavir would have increased platelet reactivity.

METHODS

In a prospective study in adult HIV-infected patients, we determined associations between antiretrovirals (ARVs), and in particular the nucleoside reverse transcriptase inhibitor abacavir, and platelet reactivity by measuring time-dependent platelet aggregation in response to agonists: adenosine diphosphate (ADP), thrombin receptor-activating peptide (TRAP), collagen, and epinephrine.

RESULTS

Of 120 subjects, 40 were ARV-naive and 80 ARV-treated, 40 of whom were receiving abacavir. No consistent differences in platelet reactivity were observed between the ARV-naive and ARV-treated groups. In contrast, within the ARV-treated group, abacavir-treated subjects had consistently higher percentages of platelet aggregation upon exposure to ADP, collagen, and epinephrine (P = .037, P = .022, and P = .032, respectively) and had platelets that were more sensitive to aggregation upon exposure to TRAP (P = .025).

CONCLUSIONS

The consistent increases in platelet reactivity observed in response to a range of agonists provides a plausible underlying mechanism to explain the reversible increased rates of MI observed in abacavir-treated patients.

Endocrine complications of human immunodeficiency virus infection: hypogonadism, bone disease and tenofovir-related toxicity

Treatment with highly active antiretroviral therapy (HAART) has revolutionized care of patients with HIV infection. The cost of increased survival has been antiretroviral toxicity and increasing age-related co-morbidities that include significant metabolic issues. Hypogonadism was first described in the setting of advanced AIDS and can be primary or secondary. Data regarding treatment largely concern patients with wasting. Varied syndromes involving bone have been described in patients with HIV including osteonecrosis, low bone mineral density (BMD) and osteoporosis, and rarely osteomalacia. Low BMD leading to osteoporosis is the most common bone pathology and may be as a result of HIV infection, drug toxicity or co-morbidities. However, increasingly fragility fractures are reported in HIV-infected patients, suggesting bone demineralization in this population is of clinical relevance. Further research is required to understand its pathogenesis and determine effective management; however, initiation of antiretroviral therapy seems to accelerate (in the short-term) bone demineralization. One particular antiretroviral agent, tenofovir is widely used and is potentially implicated as having a greater role in long-term bone and renal dysfunction. As this population ages, screening for low BMD will become increasingly more important.

HIV infection and bone disease: implications for an aging population

Now more than ever, the management of age-related problems, from cardiovascular morbidity to bone pathology, is increasingly relevant for HIV physicians. Low bone mineral density (BMD) and fractures are more common in HIV-infected patients. Although a multifactorial aetiology underlies this condition, increasing evidence suggests a role for antiretroviral therapy in low BMD, especially upon initiation. This review will detail the epidemiology, pathogenesis, diagnosis and management of osteoporosis and low BMD in HIV-infected patients, with particular emphasis on aging.