Age-related changes in plasma biomarkers and their association with mortality in COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19)-induced mortality occurs predominantly in older patients. Several immunomodulating therapies seem less beneficial in these patients. The biological substrate behind these observations is unknown. The aim of this study was to obtain insight into the association between ageing, the host response and mortality in patients with COVID-19.

METHODS

We determined 43 biomarkers reflective of alterations in four pathophysiological domains: endothelial cell and coagulation activation, inflammation and organ damage, and cytokine and chemokine release. We used mediation analysis to associate ageing-driven alterations in the host response with 30-day mortality. Biomarkers associated with both ageing and mortality were validated in an intensive care unit and external cohort.

RESULTS

464 general ward patients with COVID-19 were stratified according to age decades. Increasing age was an independent risk factor for 30-day mortality. Ageing was associated with alterations in each of the host response domains, characterised by greater activation of the endothelium and coagulation system and stronger elevation of inflammation and organ damage markers, which was independent of an increase in age-related comorbidities. Soluble tumour necrosis factor receptor 1, soluble triggering receptor expressed on myeloid cells 1 and soluble thrombomodulin showed the strongest correlation with ageing and explained part of the ageing-driven increase in 30-day mortality (proportion mediated: 13.0%, 12.9% and 12.6%, respectively).

CONCLUSIONS

Ageing is associated with a strong and broad modification of the host response to COVID-19, and specific immune changes likely contribute to increased mortality in older patients. These results may provide insight into potential age-specific immunomodulatory targets in COVID-19.

Differences in incidence, nature of symptoms, and duration of long COVID among hospitalised migrant and non-migrant patients in the Netherlands: a retrospective cohort study

Background

Comprehensive data on long COVID across ethnic and migrant groups are lacking. We investigated incidence, nature of symptoms, clinical predictors, and duration of long COVID among COVID-19 hospitalised patients in the Netherlands by migration background (Dutch, Turkish, Moroccan, and Surinamese origin, Others).

Methods

We used COVID-19 admissions and follow up data (January 2021-July 2022) from Amsterdam University Medical Centers. We calculated long COVID incidence proportions per NICE guidelines by migration background and assessed for clinical predictors via robust Poisson regressions. We then examined associations between migration background and long COVID using robust Poisson regressions and adjusted for derived clinical predictors, and other biologically relevant factors. We also assessed long COVID symptom persistence at one-year post-discharge.

Findings

1886 patients were included. 483 patients had long COVID (26%, 95% CI 24-28%) at 12 weeks post-discharge. Symptoms like dizziness, joint pain, insomnia, and headache varied by migration background. Clinical predictors of long COVID were female sex, hospital admission duration, intensive care unit admission, and receiving oxygen, or corticosteroid therapy. Long COVID risk was higher among patients with migration background than Dutch origin patients after adjustments for derived clinical predictors, age, smoking, vaccination status, comorbidities and remdesivir treatment. Only 14% of long COVID symptoms persisted at one-year post-discharge.

Interpretation

There are significant differences in occurrence, nature of symptoms, and duration of long COVID by migration background. Studies assessing the spectrum of functional limitation and access to post-COVID healthcare are needed to help plan for appropriate and accessible healthcare interventions.

Funding

The Amsterdam UMC COVID-19 biobank is supported by the Amsterdam UMC Corona Research Fund and the Talud Foundation (Stichting Talud). The current analyses were supported by the Novo Nordisk Foundation [NNF21OC0067528].

Neurofilament light increases over time in severe COVID-19 and is associated with delirium

Neurological monitoring in sedated Intensive Care Unit patients is constrained by the lack of reliable blood-based biomarkers. Neurofilament light is a cross-disease biomarker for neuronal damage with potential clinical applicability for monitoring Intensive Care Unit patients. We studied the trajectory of neurofilament light over a month in Intensive Care Unit patients diagnosed with severe COVID-19 and explored its relation to clinical outcomes and pathophysiological predictors. Data were collected over a month in 31 Intensive Care Unit patients (166 plasma samples) diagnosed with severe COVID-19 at Amsterdam University Medical Centre, and in the first week after emergency department admission in 297 patients with COVID-19 (635 plasma samples) admitted to Massachusetts General hospital. We observed that Neurofilament light increased in a non-linear fashion in the first month of Intensive Care Unit admission and increases faster in the first week of Intensive Care Unit admission when compared with mild-moderate COVID-19 cases. We observed that baseline Neurofilament light did not predict mortality when corrected for age and renal function. Peak neurofilament light levels were associated with a longer duration of delirium after extubation in Intensive Care Unit patients. Disease severity, as measured by the sequential organ failure score, was associated to higher neurofilament light values, and tumour necrosis factor alpha levels at baseline were associated with higher levels of neurofilament light at baseline and a faster increase during admission. These data illustrate the dynamics of Neurofilament light in a critical care setting and show associations to delirium, disease severity and markers for inflammation. Our study contributes to determine the clinical utility and interpretation of neurofilament light levels in Intensive Care Unit patients.

Anti-C5a antibody vilobelimab treatment and the effect on biomarkers of inflammation and coagulation in patients with severe COVID-19: a substudy of the phase 2 PANAMO trial

We recently reported in the phase 3 PANAMO trial that selectively blocking complement 5a (C5a) with vilobelimab led to improved survival in critically ill COVID-19 patients. C5a is an important contributor to the innate immune system and can also activate the coagulation system. High C5a levels have been reported in severely ill COVID-19 patients and correlate with disease severity and mortality. Previously, we assessed the potential benefit and safety of vilobelimab in severe COVID-19 patients. In the current substudy of the phase 2 PANAMO trial, we aim to explore the effects of vilobelimab on various biomarkers of inflammation and coagulation. Between March 31 and April 24, 2020, 17 patients with severe COVID-19 pneumonia were enrolled in an exploratory, open-label, randomised phase 2 trial. Blood markers of complement, endothelial activation, epithelial barrier disruption, inflammation, neutrophil activation, neutrophil extracellular trap (NET) formation and coagulopathy were measured using enzyme-linked immunosorbent assay (ELISA) or utilizing the Luminex platform. During the first 15 days after inclusion, change in biomarker concentrations between the two groups were modelled with linear mixed-effects models with spatial splines and compared. Eight patients were randomized to vilobelimab treatment plus best supportive care (BSC) and nine patients were randomized to BSC only. A significant decrease over time was seen in the vilobelimab plus BSC group for C5a compared to the BSC only group (p < 0.001). ADAMTS13 levels decreased over time in the BSC only group compared to the vilobelimab plus BSC group (p < 0.01) and interleukin-8 (IL-8) levels were statistically more suppressed in the vilobelimab plus BSC group compared to the BSC group (p = 0.03). Our preliminary results show that C5a inhibition decreases the inflammatory response and hypercoagulability, which likely explains the beneficial effect of vilobelimab in severe COVID-19 patients. Validation of these results in a larger sample size is warranted.

Plasma NfL trajectory during ICU‐treatment of COVID‐19 patients: A prospective cohort study

Background

COVID‐19 is a respiratory disease where neurological sequelae are frequently reported. Neurofilament light (NfL) in plasma is a validated biomarker for neuronal damage. We assessed the trajectory of NfL levels in intensive care unit (ICU) patients diagnosed with COVID‐19, and studied its relationship to clinical outcomes and markers of hypothesized pathophysiological mechanisms.

Method

As part of the Art‐Deco study and Amsterdam UMC COVID‐biobank, longitudinal samples and clinical data were collected weekly from a cohort of 31 prospectively admitted ICU patients with a minimum of 7 days of ventilation. The mean±sd age was 63±11 years. Admission duration ranged from 14‐35 days and 156 samples were collected. We evaluated the NfL trajectory over time, and whether this trajectory differed by 90‐day mortality outcome. Due to the non‐linear trajectory of NfL, we applied linear mixed models including cubic splines for the time variable. Secondly, we tested whether baseline or peak NfL levels predicted mortality (n=7/31), delirium incidence after detubation (n=18/22), and duration of delirium (6±6 days). Third, we assessed if disease severity (day 7 Sequential Organ Failure Assessment [SOFA] score) and baseline hypoxemia (pAO2 before intubation), inflammation (IL1‐b, IL‐6, IL‐8, TNF‐α), and coagulopathy (d‐dimer, presence of pulmonary embolism) were predictive of the NfL trajectory. For the latter models, we included an interaction term for the pathophysiological markers in the linear mixed models. All models were adjusted for age.

Result

NfL increased during ICU admission (p<001), and persisted longer in the non‐survivors (p<0.05;Figure 1). Baseline or maximum NfL was not predictive of mortality or delirium incidence. However, maximum NfL correlated to the duration of delirium (r=0.5;p=0.02). From the pathophysiological markers, SOFA scores (p<0.05) and baseline TNF‐α (p<0.05) were related to a stronger increase of NfL over time.

Conclusion

NfL levels increased over time and plateaued after 2‐3 weeks in most COVID‐19 patients at the ICU. Peak levels of NfL were predictive of delirium persistence. Repeated NfL levels may provide a future method for monitoring neurological outcomes in sedated ICU patients. Disease severity and specific inflammatory components appear important predictors of the NfL trajectory reflecting axonal damage in severe COVID‐19 patients.

Brain-derived neurotrophic factor, a new soluble biomarker for malignant pleural mesothelioma involved in angiogenesis

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer related to asbestos exposure. The discovery of soluble biomarkers with diagnostic/prognostic and/or therapeutic properties would improve therapeutic care of MPM patients. Currently, soluble biomarkers described present weaknesses preventing their use in clinic. This study aimed at evaluating brain-derived neurotrophic factor (BDNF), we previously identified using transcriptomic approach, in MPM. We observed that high BDNF expression, at the mRNA level in tumors or at the protein level in pleural effusions (PE), was a specific hallmark of MPM samples. This protein presented significant but limited diagnostic properties (area under the curve (AUC) = 0.6972, p < 0.0001). Interestingly, high BDNF gene expression and PE concentration were predictive of shorter MPM patient survival (13.0 vs 8.3 months, p < 0.0001, in PE). Finally, BDNF did not affect MPM cell oncogenic properties but was implicated in PE-induced angiogenesis. In conclusion, BDNF appears to be a new interesting biomarker for MPM and could also be a new therapeutic target regarding its implication in angiogenesis.

Facilitators and barriers to birth preparedness and complication readiness in rural Rwanda among community health workers and community members: a qualitative study

BACKGROUND

Birth preparedness and complication readiness (BP/CR) comprise a strategy to make women plan for birth and encourage them to seek professional care in order to reduce poor pregnancy outcome. We aimed to understand the facilitators and barriers to BP/CR among community health workers (CHWs) and community members in rural Rwanda.

METHODS

Eight focus group discussions were conducted with 88 participants comprising of CHWs, elderly women aged 45-68 and men aged 18-59, as well as two key informant interviews in Musanze district, Rwanda, between November and December 2015. Qualitative data were digitally recorded, transcribed verbatim and analysed using content analysis.

RESULTS

Participants perceived the importance of family assistance, medical insurance and attending antenatal care (ANC) to facilitate BP/CR and enhance professional care at birth. CHWs reinforced BP/CR messages by SMS alerts and during community gatherings. 'Ubudehe (collective action to combat poverty)' was known as a tool to identify the poorest families in need of government aid to pay for medical care. Disrespect and abuse of women during labor by health workers were perceived as important barriers to access professional care, as well as conflicting health policies such as user fees for ANC and family planning services, and imposing fines on women giving birth outside health facilities.

CONCLUSION

CHWs, ANC and medical insurance are perceived to be important facilitators of BP/CR. Respectful care is paramount for improved maternal health. There is a need for addressing inconsistent health policies hindering the intention to access professional care.

Birth preparedness and complication readiness among pregnant women admitted in a rural hospital in Rwanda

BACKGROUND

With an aim to prevent adverse pregnancy outcomes, 'birth preparedness and complication readiness' (BP/CR) promotes timely access to skilled maternal and neonatal services. Objective of this study was to assess implementation of BP/CR among pregnant women admitted with obstetric emergencies in rural Rwanda.

METHODS

A cross-sectional study among pregnant women who were referred to Ruhengeri hospital between July and November 2015. The 'Safe Motherhood questionnaire' as developed by Jhpiego's Maternal and Neonatal Health Program was used to collect data. Women were asked to mention key danger signs and respond as to whether they had identified: (A) skilled birth attendant, (B) location to give birth, (C) mode of transport, (D) money to cover health care expenditure. Women who answered 'yes' to three or four items were labeled 'well prepared'. Multivariate logistic regression analysis was conducted to compare the 'well prepared' and 'less prepared'.

RESULTS

With regard to complication readiness, out of 350 women, 296 (84.6%), 271 (77.4%) and 288 (82.3%) could mention at least one key danger sign during pregnancy, labor and postpartum respectively, but only 23 (6.6%) could mention three or more key danger signs during all three periods. With regard to birth preparedness, 46 (13.1%) women had identified a skilled birth attendant, 68 (19.4%) birth location, 76 (21.7%) mode of transport, and 306 (87.4%) had saved money for health care costs. Seventy-eight women (22.3%) were 'well prepared', associated factors being first time pregnancy (adjusted Odds Ratio (aOR) = 3.2; 95% CI; 1.2-5.8), knowledge of at least two danger signs (aOR = 2.8; 95% CI; 1.7-3.9) and having been assisted by a community health worker at the antenatal clinic (aOR = 2.2, 95% CI; 1.3-3.7).

CONCLUSION

Knowledge of obstetric danger signs was suboptimal and birth preparedness low. We recommend review of practices regarding health promotion in antenatal care, taking care not to exclude multiparous women from messages related to birth preparedness, and do promote use of community health workers to enhance effectiveness of BP/CR.