Control of complement-induced inflammatory responses to SARS-CoV-2 infection by anti-SARS-CoV-2 antibodies

Dysregulated immune responses contribute to the excessive and uncontrolled inflammation observed in severe COVID-19. However, how immunity to SARS-CoV-2 is induced and regulated remains unclear. Here, we uncover the role of the complement system in the induction of innate and adaptive immunity to SARS-CoV-2. Complement rapidly opsonizes SARS-CoV-2 particles via the lectin pathway. Complement-opsonized SARS-CoV-2 efficiently induces type-I interferon and pro-inflammatory cytokine responses via activation of dendritic cells, which are inhibited by antibodies against the complement receptors (CR) 3 and 4. Serum from COVID-19 patients, or monoclonal antibodies against SARS-CoV-2, attenuate innate and adaptive immunity induced by complement-opsonized SARS-CoV-2. Blocking of CD32, the FcγRII antibody receptor of dendritic cells, restores complement-induced immunity. These results suggest that opsonization of SARS-CoV-2 by complement is involved in the induction of innate and adaptive immunity to SARS-CoV-2 in the acute phase of infection. Subsequent antibody responses limit inflammation and restore immune homeostasis. These findings suggest that dysregulation of the complement system and FcγRII signaling may contribute to severe COVID-19.

Mental health up to 12 months following SARS-CoV-2 infection: A prospective cohort study

OBJECTIVE

To investigate to what extent individuals report clinically relevant levels of depression, anxiety, post-traumatic stress disorder (PTSD) symptoms and concentration problems up to 12 months following COVID-19 symptom onset, using validated questionnaires.

METHODS

RECoVERED, a prospective cohort study in Amsterdam, the Netherlands, enrolled both hospitalized and community-dwelling adult participants diagnosed with SARS-CoV-2. Symptoms of depression and anxiety were assessed with the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7 1, 3, 6 and 12 months following illness onset. The DSM-V PTSD checklist was administered at month 3 and 9. Concentration problems were assessed using the Checklist Individual Strength concentration subscale at month 1 and 12. Generalized Estimating Equations were used to determine factors related with clinically relevant levels of depression-, anxiety- and PTSD-symptoms and concentration problems over time.

RESULTS

In 303 individuals, the prevalence of clinically relevant symptoms of depression, anxiety and concentration problems was 10.6% (95%CI = 7.2-15.4), 7.0% (95%CI = 4.4-11.2) and 33.6% (95%CI = 27.7-40.1), respectively, twelve months after infection. Nine months after illness onset, 4.2% (95%CI = 2.3-7.7) scored within the clinical range of PTSD. Risk factors for an increased likelihood of reporting mental health problems during follow up included initial severe/critical COVID-19, non-Dutch origin, psychological problems prior to COVID-19 and being infected during the first COVID-19 wave.

CONCLUSION

Our findings highlight that a minority of patients with COVID-19 face clinically relevant symptoms of depression, anxiety or PTSD up to 12 months after infection. The prevalence of concentration problems was high. This study contributes to the identification of specific groups for which support after initial illness is indicated.

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.

Neurobiological basis and risk factors of persistent fatigue and concentration problems after COVID-19: study protocol for a prospective case-control study (VeCosCO)

INTRODUCTION

The risk factors for persistent fatigue and cognitive complaints after infection with SARS-CoV-2 and the underlying pathophysiology are largely unknown. Both clinical factors and cognitive-behavioural factors have been suggested to play a role in the perpetuation of complaints. A neurobiological aetiology, such as neuroinflammation, could be the underlying pathophysiological mechanism for persisting complaints.To unravel factors associated with persisting complaints, VeCosCO will compare individuals with and without persistent fatigue and cognitive complaints >3 months after infection with SARS-CoV-2. The study consists of two work packages. The first work package aims to (1) investigate the relation between persisting complaints and neuropsychological functioning; (2) determine risk factors and at-risk phenotypes for the development of persistent fatigue and cognitive complaints, including the presence of postexertional malaise and (3) describe consequences of persistent complaints on quality of life, healthcare consumption and physical functioning. The second work package aims to (1) determine the presence of neuroinflammation with [¹⁸F]DPA-714 whole-body positron emission tomography (PET) scans in patients with persisting complaints and (2) explore the relationship between (neuro)inflammation and brain structure and functioning measured with MRI.

METHODS AND ANALYSIS

This is a prospective case-control study in participants with and without persistent fatigue and cognitive complaints, >3 months after laboratory-confirmed SARS-CoV-2 infection. Participants will be mainly included from existing COVID-19 cohorts in the Netherlands covering the full spectrum of COVID-19 acute disease severity. Primary outcomes are neuropsychological functioning, postexertional malaise, neuroinflammation measured using [¹⁸F]DPA-714 PET, and brain functioning and structure using (f)MRI.

ETHICS AND DISSEMINATION

Work package 1 (NL79575.018.21) and 2 (NL77033.029.21) were approved by the medical ethical review board of the Amsterdam University Medical Centers (The Netherlands). Informed consent is required prior to participation in the study. Results of this study will be submitted for publication in peer-reviewed journals and shared with the key population.

Health-related quality of life among persons with initial mild, moderate, and severe or critical COVID-19 at 1 and 12 months after infection: a prospective cohort study

BACKGROUND

Currently, there is limited evidence about the long-term impact on physical, social and emotional functioning, i.e. health-related quality of life (HRQL) after mild or moderate COVID-19 not requiring hospitalization. We compared HRQL among persons with initial mild, moderate or severe/critical COVID-19 at 1 and 12 months following illness onset with Dutch population norms and investigated the impact of restrictive public health control measures on HRQL.

METHODS

RECoVERED, a prospective cohort study in Amsterdam, the Netherlands, enrolled adult participants after confirmed SARS-CoV-2 diagnosis. HRQL was assessed with the Medical Outcomes Study Short Form 36-item health survey (SF-36). SF-36 scores were converted to standard scores based on an age- and sex-matched representative reference sample of the Dutch population. Differences in HRQL over time were compared among persons with initial mild, moderate or severe/critical COVID-19 using mixed linear models adjusted for potential confounders.

RESULTS

By December 2021, 349 persons were enrolled of whom 269 completed at least one SF-36 form (77%). One month after illness onset, HRQL was significantly below population norms on all SF-36 domains except general health and bodily pain among persons with mild COVID-19. After 12 months, persons with mild COVID-19 had HRQL within population norms, whereas persons with moderate or severe/critical COVID-19 had HRQL below population norms on more than half of the SF-36 domains. Dutch-origin participants had significantly better HRQL than participants with a migration background. Participants with three or more COVID-19 high-risk comorbidities had worse HRQL than part participants with fewer comorbidities. Participants who completed the SF-36 when restrictive public health control measures applied reported less limitations in social and physical functioning and less impaired mental health than participants who completed the SF-36 when no restrictive measures applied.

CONCLUSIONS

Twelve months after illness onset, persons with initial mild COVID-19 had HRQL within population norms, whereas persons with initial moderate or severe/critical COVID-19 still had impaired HRQL. Having a migration background and a higher number of COVID-19 high-risk comorbidities were associated with worse HRQL. Interestingly, HRQL was less impaired during periods when restrictive public health control measures were in place compared to periods without.

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.

Severe Fatigue in the First Year Following SARS-CoV-2 Infection: A Prospective Cohort Study

Background

Severe fatigue can persist for months after coronavirus disease 2019 (COVID-19) onset. This longitudinal study describes fatigue severity and its determinants up to 12 months after illness onset across the full spectrum of COVID-19 severity.

Methods

RECoVERED, a prospective cohort study in Amsterdam, the Netherlands, enrolled participants aged ≥16 years after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnosis. Fatigue was measured using the validated Short Fatigue Questionnaire (SFQ; range 4–28) at months 1, 3, 6, 9, and 12 of follow-up. Fatigue severity was modeled over time using mixed-effects linear regression. Determinants of severe fatigue (SFQ ≥18) at 6 months since illness onset (ie, persistent fatigue) were identified using logistic regression.

Results

Between May 2020 and July 2021, 303 participants completed at least 1 fatigue questionnaire. Twelve months after illness onset, 17.4% (95% CI, 6.7% to 38.3%), 21.6% (95% CI, 11.2% to 37.7%), and 44.8% (95% CI, 28.0% to 62.9%) of participants with mild, moderate, and severe/critical COVID-19 (World Health Organization definition), respectively, experienced severe fatigue. When adjusting for age and sex, having ≥3 comorbidities (P = .007), severe/critical COVID-19 (P = .002), low mood (P < .001), and dyspnea in the first 2 weeks of illness (P = .001) were associated with more severe fatigue over time. Severe/critical COVID-19 (adjusted odds ratio [aOR], 3.37; 95% CI, 1.28 to 8.93) and low mood at enrollment (aOR, 2.43; 95% CI, 1.11 to 5.29) were associated with persistent fatigue. Recovery rarely occurred beyond 6 months after illness onset, regardless of COVID-19 severity.

Conclusions

The occurrence of severe fatigue in our cohort was high, especially among those with initially severe/critical COVID-19, with little recovery beyond 6 months after illness onset. Our findings highlight an urgent need for improved understanding of persistent severe fatigue following COVID-19 to help inform prevention and intervention.

Cohort profile: the Netherlands Cohort Study on Acute HIV infection (NOVA), a prospective cohort study of people with acute or early HIV infection who immediately initiate HIV treatment

PURPOSE

Initiation of combination antiretroviral therapy (cART) during acute or early HIV-infection (AEHI) limits the size of the viral reservoir and preserves immune function. This renders individuals who started cART during AEHI promising participants in HIV-cure trials. Therefore, we established a multicentre prospective cohort study in the Netherlands that enrols people with AEHI. In anticipation of future cure trials, we will longitudinally investigate the properties of the viral reservoir size and HIV-specific immune responses among cohort participants.

PARTICIPANTS

Participants immediately initiate intensified cART: dolutegravir, emtricitabine/tenofovir and darunavir/ritonavir (DRV/r). After 4 weeks, once baseline resistance data are available, DRV/r is discontinued. Three study groups are assembled based on the preparedness of individuals to participate in the extensiveness of sampling. Participants accepting immediate treatment and follow-up but declining additional sampling are included in study group 1 ('standard') and routine diagnostic procedures are performed. Participants willing to undergo blood, leukapheresis and semen sampling are included in study group 2 ('less invasive'). In study group 3 ('extended'), additional tissue (gut-associated lymphoid tissue, peripheral lymph node) and cerebrospinal fluid sampling are performed.

FINDINGS TO DATE

Between 2015 and 2020, 140 individuals with AEHI have been enrolled at nine study sites. At enrolment, median age was 36 (IQR 28-47) years, and 134 (95.7%) participants were men. Distribution of Fiebig stages was as follows: Fiebig I, 3 (2.1%); II, 20 (14.3%); III, 7 (5.0%); IV, 49 (35.0%); V, 39 (27.9%); VI, 22 (15.7%). Median plasma HIV RNA was 5.9 (IQR 4.7-6.7) log10 copies/mL and CD4 count 510 (IQR 370-700) cells/mm3. Median time from cART initiation to viral suppression was 8.0 (IQR 4.0-16.0) weeks.

FUTURE PLANS

The Netherlands Cohort Study on Acute HIV infection remains open for participant enrolment and for additional sites to join the network. This cohort provides a unique nationwide platform for conducting future in-depth virological, immunological, host genetic and interventional studies investigating HIV-cure strategies.

Evolution of COVID-19 symptoms during the first 12 months after illness onset

BACKGROUND

Few robust longitudinal data on long-term COVID-19 symptoms are available. We evaluated symptom onset, severity and recovery across the full spectrum of disease severity, up to one year after illness onset.

METHODS

The RECoVERED Study is a prospective cohort study based in Amsterdam, the Netherlands. Participants aged≥18 years were enrolled following SARS-CoV-2 diagnosis via the local Public Health Service and from hospitals. Standardised symptom questionnaires were completed at enrolment, one week and month later, and monthly thereafter. Clinical severity was defined according to WHO criteria. Kaplan-Meier methods were used to compare time from illness onset to symptom recovery, by clinical severity. We examined determinants of time to recovery using multivariable Cox proportional hazards models.

RESULTS

Between 11 May 2020 and 1 May 2021, 342 COVID-19 patients (192[56%] male) were enrolled, of whom 99/342(29%) had mild, 145/342(42%) moderate, 56/342(16%) severe and 42/342(12%) critical disease. The proportion of participants who reported at least one persistent symptom at 12 weeks after illness onset was greater in those with severe/critical disease (86.7%[95%CI=76.5-92.7%]) compared to those with mild or moderate disease (30.7%[95%CI=21.1-40.9%] and 63.8%[95%CI=54.8-71.5%]). At twelve months after illness onset, two-fifths of participants (40.7%[95%CI=34.2-47.1]) continued to report ≥1 symptom. Recovery was slower in female compared to male participants (aHR 0.65[95%CI=0.47-0.92]) and those with a BMI≥30kg/m 2 compared to BMI<25kg/m 2 (HR 0.62[95%CI=0.39-0.97]).

CONCLUSIONS

COVID-19 symptoms persisted for one year after illness onset, even in some individuals with mild disease. Female sex and obesity were the most important determinants of speed of recovery from symptoms.

Understanding Reasons for HIV Late Diagnosis: A Qualitative Study Among HIV-Positive Individuals in Amsterdam, The Netherlands

Since the introduction of effective anti-retroviral therapy, early diagnosis and treatment of HIV have become increasingly important from individual and public health perspectives. People who are diagnosed with a CD4 count below 350 cells/µL blood are today considered to be “late” diagnoses. In an effort to understand the reasons for late diagnosis, we conducted in-depth interviews (n = 14) in Amsterdam, the Netherlands. Two main factors were identified: psychosocial factors and health-system factors. Psychosocial factors relate to people’s personal relationship with health professionals, low risk perception, fear related to the outcome of testing, and trauma from observed past experiences of living with HIV. Health-system factors relate to institutional barriers and missed opportunities during client-provider interactions. We conclude that in order to mitigate late diagnosis, the social and institutional context within which HIV testing is conducted should be addressed.

Therapeutic options for CTLA-4 insufficiency

BACKGROUND

Heterozygous germline mutations in cytotoxic T lymphocyte-associated antigen-4 (CTLA4) impair the immunomodulatory function of regulatory T cells. Affected individuals are prone to life-threatening autoimmune and lymphoproliferative complications. A number of therapeutic options are currently being used with variable effectiveness.

OBJECTIVE

Our aim was to characterize the responsiveness of patients with CTLA-4 insufficiency to specific therapies and provide recommendations for the diagnostic workup and therapy at an organ-specific level.

METHODS

Clinical features, laboratory findings, and response to treatment were reviewed retrospectively in an international cohort of 173 carriers of CTLA4 mutation. Patients were followed between 2014 and 2020 for a total of 2624 months from diagnosis. Clinical manifestations were grouped on the basis of organ-specific involvement. Medication use and response were recorded and evaluated.

RESULTS

Among the 173 CTLA4 mutation carriers, 123 (71%) had been treated for immune complications. Abatacept, rituximab, sirolimus, and corticosteroids ameliorated disease severity, especially in cases of cytopenias and lymphocytic organ infiltration of the gut, lungs, and central nervous system. Immunoglobulin replacement was effective in prevention of infection. Only 4 of 16 patients (25%) with cytopenia who underwent splenectomy had a sustained clinical response. Cure was achieved with stem cell transplantation in 13 of 18 patients (72%). As a result of the aforementioned methods, organ-specific treatment pathways were developed.

CONCLUSION

Systemic immunosuppressants and abatacept may provide partial control but require ongoing administration. Allogeneic hematopoietic stem cell transplantation offers a possible cure for patients with CTLA-4 insufficiency.

Head-to-head validation of six immunoassays for SARS-CoV-2 in hospitalized patients

BACKGROUND

Detecting SARS-CoV-2 antibodies may help to diagnose COVID-19. Head-to-head validation of different types of immunoassays in well-characterized cohorts of hospitalized patients remains needed.

METHODS

We validated three chemiluminescence immunoassays (CLIAs) (Liaison, Elecsys, and Abbott) and one single molecule array assay (SIMOA) (Quanterix) for automated analyzers, one rapid immunoassay RIA (AllTest), and one ELISA (Wantai) in parallel in first samples from 126 PCR confirmed COVID-19 hospitalized patients and 158 pre-COVID-19 patients. Specificity of the AllTest was also tested in 106 patients with confirmed parasitic and dengue virus infections. Specificity of the Wantai assay was not tested due to limitations in sample volumes.

RESULTS

Overall sensitivity in first samples was 70.6 % for the Liaison, 71.4 % for the Elecsys, 75.4 % for the Abbott, 70.6 % for the Quanterix, 77.8 % for the AllTest, and 88.9 % for the Wantai assay, respectively. Sensitivity was between 77.4 % (Liaison) and 94.0 % (Wantai) after 10 dpso. No false positive results were observed for the Elecsys and Abbott assays. Specificity was 91.1 % for the Quanterix, 96.2 % for the Liaison, and 98.1 % for the AllTest assay, respectively.

CONCLUSION

We conclude that low sensitivity of all immunoassays limits their use early after onset of illness in diagnosing COVID-19 in hospitalized patients. After 10 dpso, the Wantai ELISA has a relatively high sensitivity, followed by the point-of-care AllTest RIA that compares favorably with automated analyzer immunoassays.