Establishment of a pediatric COVID-19 biorepository: unique considerations and opportunities for studying the impact of the COVID-19 pandemic on children

From blueprint to biobank: Leveraging expert recommendations for implementing change (ERIC) to pediatric cancer biobanking in Pakistan

BACKGROUND

In low- and middle-income countries, limited infrastructure and resources hinder biobank establishment, affecting specimen diversity. Addressing this gap is crucial for equitable health outcomes, as current databases are skewed towards Northern-European populations. In Pakistan, pediatric cancer biobanks are non-existent. Indus Hospital & Health Network (IHHN) in Karachi, with its large pediatric cancer unit, aims to establish a biobank to address region-specific pediatric cancer research needs. This manuscript describes the biobank implementation process using implementation science frameworks.

METHODS

The pediatric cancer biobank at IHHN collects FFPE specimens for solid tumors, and isolated mononuclear cells from peripheral blood and bone marrow of suspected acute leukemia. Implementation planning workgroups included clinicians, EMR, IT, management, senior leadership, IRB, and external support from UNC and St. Jude Children's Cancer Hospital. The selection of applicable ERIC (Expert Recommendations for Implementing Change) strategies through stakeholder workgroups considered scope, budget, and feasibility, and context. Standard protocols from ISBER and BCNet guided alignment with best practices. IHHN's past experiences and tacit knowledge gained through rapid, successful implementation also facilitated strategy selection. The EPIS framework (exploration, preparation, implementation, sustainment) was used to map and organize the selected intervention strategies.

RESULTS

Biobank implementation at IHHN, organized by EPIS stages, has been described through a set of 41 implementation strategies. Of these, 34 were selected out of 73 originally published ERIC strategies, while 7 were added based on contextually based workgroup consensus. 599 acute leukemia and 1137 solid tumor specimens have been banked since inception of the biobank operations 2 years earlier. The implementation activities and challenges described include infrastructure, swift specimen collection, prior to treatment, and informed consent. The ancillary processes including training and quality control have also been described and related data presented.

CONCLUSION

The implementation of Pakistan's first acute leukemia biobank using ERIC and EPIS frameworks offers a structured approach beneficial for settings with limited biobanking experience. This intervention aligns with recognized implementation science frameworks, while addressing aspects pertinent in low- and middle-income countries.

Antigen-specific T cell responses in SARS-CoV-2 mRNA-vaccinated children

SARS-CoV-2 mRNA vaccines elicit humoral responses in children that are comparable to those in adults. However, early-life T cell responses are distinct from adult ones, and questions remain about the nature and kinetics of mRNA vaccine-induced T cell responses in children. We report that Pfizer BNT162b2 mRNA vaccination elicits a significant antigen-specific CD4+ T cell response in the ≥12-year-old cohort. This response is weaker in magnitude in the 5- to 11-year-old cohort and is not improved by a higher vaccine dose (Moderna mRNA1273, 100 μg), suggesting distinct developmental programming that may underscore early-life T cell immunity. Increased effector phenotypes of antigen-specific T cells in younger children correspond with elevated anti-receptor binding domain antibody levels, albeit at the cost of memory generation. These studies highlight aspects of age-specific adaptive immune responses and the need for careful consideration of priming conditions including vaccine dose and adjuvant in the pediatric population.

Long-term humoral signatures following acute pediatric COVID-19 and Multisystem Inflammatory Syndrome in Children

BACKGROUND

Although most children experience mild symptoms during acute SARS-CoV-2 infection, some develop the severe post-COVID-19 complication, Multisystem Inflammatory Syndrome in Children (MIS-C). While acute presentations of COVID-19 and MIS-C have been well immunophenotyped, little is known about the lasting immune profile in children after acute illness.

METHODS

Children 2 months-20 years of age presenting with either acute COVID-19 (n = 9) or MIS-C (n = 12) were enrolled in a Pediatric COVID-19 Biorepository at a single medical center. We deeply profiled humoral immune responses and circulating cytokines following pediatric COVID-19 and MIS-C.

RESULTS

Twenty-one children and young adults provided blood samples at both acute presentation and 6-month follow-up (mean: 6.5 months; standard deviation: 1.77 months). Pro-inflammatory cytokine elevations resolved after both acute COVID-19 and MIS-C. Humoral profiles continue to mature after acute COVID-19, displaying decreasing IgM and increasing IgG over time, as well as stronger effector functions, including antibody-dependent monocyte activation. In contrast, MIS-C immune signatures, especially anti-Spike IgG1, diminished over time.

CONCLUSIONS

Here, we show the mature immune signature after pediatric COVID-19 and MIS-C, displaying resolving inflammation with recalibration of the humoral responses. These humoral profiles highlight immune activation and vulnerabilities over time in these pediatric post-infectious cohorts.

IMPACT

The pediatric immune profile matures after both COVID-19 and MIS-C, suggesting a diversified anti-SARS-CoV-2 antibody response after resolution of acute illness. While pro-inflammatory cytokine responses resolve in the months following acute infection in both conditions, antibody-activated responses remain relatively heightened in convalescent COVID-19. These data may inform long-term immunoprotection from reinfection in children with past SARS-CoV-2 infections or MIS-C.

Humoral profiling of pediatric patients with cancer reveals robust immunity following anti-SARS-CoV-2 vaccination superior to natural infection

BACKGROUND

Pediatric patients with cancer infected with COVID-19 may be at higher risk of severe disease and may be unable to mount an adequate response to the virus due to compromised immunity secondary to their cancer therapy.

PROCEDURE

This study presents immunologic analyses of 20 pediatric patients with cancer, on active chemotherapy or having previously received chemotherapy, and measures their immunoglobulin titers and activation of cellular immunity response to acute SARS-CoV-2 infection and COVID-19 vaccination compared with healthy pediatric controls.

RESULTS

Forty-three patients were enrolled, of which 10 were actively receiving chemotherapy, 10 had previously received chemotherapy, and 23 were healthy controls. Pediatric patients with cancer had similar immunoglobulin titers, antibody binding capacity, and effector function assay activity after vaccination against COVID-19 compared with healthy controls, though more variability in response was noted in the cohort actively receiving chemotherapy. Compared with acute infection, vaccination against COVID-19 produced superior immunoglobulin responses, particularly IgA1, IgG1, and IgG3, and elicited superior binding capacity and effector function in children with cancer and healthy controls.

CONCLUSIONS

Pediatric patients receiving chemotherapy and those who had previously received chemotherapy had adequate immune activation after both vaccination and acute infection compared to healthy pediatric controls, although there was a demonstrated variability in response for the patients on active chemotherapy. Vaccination against COVID-19 produced superior immune responses compared to acute SARS-CoV-2 infection in pediatric patients with cancer and healthy children, underscoring the importance of vaccination even in previously infected individuals.

Circulating Spike Protein Detected in Post-COVID-19 mRNA Vaccine Myocarditis

BACKGROUND

Cases of adolescents and young adults developing myocarditis after vaccination with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-targeted mRNA vaccines have been reported globally, but the underlying immunoprofiles of these individuals have not been described in detail.

METHODS

From January 2021 through February 2022, we prospectively collected blood from 16 patients who were hospitalized at Massachusetts General for Children or Boston Children's Hospital for myocarditis, presenting with chest pain with elevated cardiac troponin T after SARS-CoV-2 vaccination. We performed extensive antibody profiling, including tests for SARS-CoV-2-specific humoral responses and assessment for autoantibodies or antibodies against the human-relevant virome, SARS-CoV-2-specific T-cell analysis, and cytokine and SARS-CoV-2 antigen profiling. Results were compared with those from 45 healthy, asymptomatic, age-matched vaccinated control subjects.

RESULTS

Extensive antibody profiling and T-cell responses in the individuals who developed postvaccine myocarditis were essentially indistinguishable from those of vaccinated control subjects, despite a modest increase in cytokine production. A notable finding was that markedly elevated levels of full-length spike protein (33.9±22.4 pg/mL), unbound by antibodies, were detected in the plasma of individuals with postvaccine myocarditis, whereas no free spike was detected in asymptomatic vaccinated control subjects (unpaired t test; P<0.0001).

CONCLUSIONS

Immunoprofiling of vaccinated adolescents and young adults revealed that the mRNA vaccine-induced immune responses did not differ between individuals who developed myocarditis and individuals who did not. However, free spike antigen was detected in the blood of adolescents and young adults who developed post-mRNA vaccine myocarditis, advancing insight into its potential underlying cause.

Neutrophil profiles of pediatric COVID-19 and multisystem inflammatory syndrome in children

Multisystem inflammatory syndrome in children (MIS-C) is a delayed-onset, COVID-19-related hyperinflammatory illness characterized by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigenemia, cytokine storm, and immune dysregulation. In severe COVID-19, neutrophil activation is central to hyperinflammatory complications, yet the role of neutrophils in MIS-C is undefined. Here, we collect blood from 152 children: 31 cases of MIS-C, 43 cases of acute pediatric COVID-19, and 78 pediatric controls. We find that MIS-C neutrophils display a granulocytic myeloid-derived suppressor cell (G-MDSC) signature with highly altered metabolism that is distinct from the neutrophil interferon-stimulated gene (ISG) response we observe in pediatric COVID-19. Moreover, we observe extensive spontaneous neutrophil extracellular trap (NET) formation in MIS-C, and we identify neutrophil activation and degranulation signatures. Mechanistically, we determine that SARS-CoV-2 immune complexes are sufficient to trigger NETosis. Our findings suggest that hyperinflammatory presentation during MIS-C could be mechanistically linked to persistent SARS-CoV-2 antigenemia, driven by uncontrolled neutrophil activation and NET release in the vasculature.

Relationship between Anti-Spike Antibodies and Risk of SARS-CoV-2 Infection in Infants Born to COVID-19 Vaccinated Mothers

The goal of this study was to investigate the relationship between anti-SARS-CoV-2-Spike IgG titers passively transferred to the fetus from maternal vaccination during pregnancy and timing of infant SARS-CoV-2 infection. Pregnant, vaccinated individuals (n = 105) and their infants (n = 107) were enrolled in a prospective cohort study from July 2021 to June 2022, linking infant anti-Spike IgG titer at birth to risk of SARS-CoV-2 infection in the first fifteen months of life. Cord blood sera were collected at delivery and infant sera were collected at two and six months of age. Anti-SARS-CoV-2-Spike IgG levels were quantified in cord and infant sera using an enzyme-linked immunosorbent assay. Infants were followed for SARS-CoV-2 infection through fifteen months of age. Anti-SARS-CoV-2-Spike IgG titers in infants declined significantly with increased age (p < 0.001). Infants with higher anti-Spike cord blood levels had significantly longer disease-free intervals prior to infection with SARS-CoV-2 (p = 0.027). While higher anti-Spike IgG titer at two months of age was associated with a longer interval to infection through nine months of age (p = 0.073), infant anti-Spike IgG titers by six months of age had no impact on disease-free interval. This cohort study suggests that passively transferred maternal IgG is protective against infant SARS-CoV-2 infection, with higher antibody levels at birth significantly associated with longer disease-free intervals. Infant antibodies and protection from SARS-CoV-2 infection wane significantly after six months, suggesting that vaccination is needed at this stage to optimize protection against COVID-19.

Challenges to biobanking in LMICs during COVID-19: time to reconceptualise research ethics guidance for pandemics and public health emergencies?

Biobanking can promote valuable health research that may lead to significant societal benefits. However, collecting, storing and sharing human samples and data for research purposes present numerous ethical challenges. These challenges are exacerbated when the biobanking efforts aim to facilitate research on public health emergencies and include the sharing of samples and data between low/middle-income countries (LMICs) and high-income countries (HICs). In this article, we explore ethical challenges for COVID-19 biobanking, offering examples from two past infectious disease outbreaks in LMICs where biobanking activities contributed to the perpetuation of global inequities. We focus on how the ethical imperative to promote the common good during public health emergencies can conflict with protecting the interests of biobank participants. We discuss how conducting biobank research under a waiver of informed consent during public health emergencies is ethically permissible, provided guidance is in place to prevent biopiracy and exploitation of vulnerable communities. We also highlight the need for biobank collaborations between LMICs and HICs to promote capacity building and benefit sharing. Finally, we offer guidance to promote the ethical oversight of biobanks and biobank research during the COVID-19 pandemic or other future public health emergencies.

Monocyte anisocytosis increases during multisystem inflammatory syndrome in children with cardiovascular complications

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening complication that can develop weeks to months after an initial SARS-CoV-2 infection. A complex, time-consuming laboratory evaluation is currently required to distinguish MIS-C from other illnesses. New assays are urgently needed early in the evaluation process to expedite MIS-C workup and initiate treatment when appropriate. This study aimed to measure the performance of a monocyte anisocytosis index, obtained on routine complete blood count (CBC), to rapidly identify subjects with MIS-C at risk for cardiac complications.

METHODS

We measured monocyte anisocytosis, quantified by monocyte distribution width (MDW), in blood samples collected from children who sought medical care in a single medical center from April 2020 to October 2020 (discovery cohort). After identifying an effective MDW threshold associated with MIS-C, we tested the utility of MDW as a tier 1 assay for MIS-C at multiple institutions from October 2020 to October 2021 (validation cohort). The main outcome was the early screening of MIS-C, with a focus on children with MIS-C who displayed cardiac complications. The screening accuracy of MDW was compared to tier 1 routine laboratory tests recommended for evaluating a child for MIS-C.

RESULTS

We enrolled 765 children and collected 846 blood samples for analysis. In the discovery cohort, monocyte anisocytosis, quantified as an MDW threshold of 24.0, had 100% sensitivity (95% CI 78-100%) and 80% specificity (95% CI 69-88%) for identifying MIS-C. In the validation cohort, an initial MDW greater than 24.0 maintained a 100% sensitivity (95% CI 80-100%) and monocyte anisocytosis displayed a diagnostic accuracy greater that other clinically available hematologic parameters. Monocyte anisocytosis decreased with disease resolution to values equivalent to those of healthy controls.

CONCLUSIONS

Monocyte anisocytosis detected by CBC early in the clinical workup improves the identification of children with MIS-C with cardiac complications, thereby creating opportunities for improving current practice guidelines.

Denis KJ, Sheehan ML, Chen JW, Davis JP, Lima R, Edlow AG, Fasano A, Balazs AB, Alter G, Yonker LM. Durability and Cross-Reactivity of SARS-CoV-2 mRNA Vaccine in Adolescent Children

Emergent SARS-CoV-2 variants and waning humoral immunity in vaccinated individuals have resulted in increased infections and hospitalizations. Children are not spared from infection nor complications of COVID-19, and the recent recommendation for boosters in individuals ages 12 years or older calls for broader understanding of the adolescent immune profile after mRNA vaccination. We tested the durability and cross-reactivity of anti-SARS-CoV-2 serologic responses over a six-month time course in vaccinated adolescents against the SARS-CoV-2 D614G ("wild type") and Omicron antigens. Serum from 77 adolescents showed that anti-Spike antibodies wane significantly over six months. After completion of a two-vaccine series, cross-reactivity against Omicron-specific receptor-binding domain (RBD) was seen. Functional humoral activation against wild type and Omicron SARS-CoV-2 also declines over time in vaccinated adolescent children. Evidence of waning mRNA-induced vaccine immunity underscores vulnerabilities in long-term pediatric protection against SARS-CoV-2 infection, while cross-reactivity highlights the additional benefits of vaccination. Characterization of adolescent immune signatures post-vaccination will inform guidance on vaccine platforms and timelines, and ultimately optimize immunoprotection of children.

Pediatric biorepository participation during the COVID-19 pandemic: predictors of enrollment and biospecimen donation

Background

Patient-level predictors of enrollment in pediatric biorepositories are poorly described. Especially in pandemic settings, understanding who is likely to enroll in a biorepository is critical to interpreting analyses conducted on biospecimens. We describe predictors of pediatric COVID-19 biorepository enrollment and biospecimen donation to identify gaps in COVID-19 research on pediatric biospecimens.

Methods

We compared data from enrollees and non-enrollees aged 0–25 years with suspected or confirmed COVID-19 infection who were approached for enrollment in the Massachusetts General Hospital pediatric COVID-19 biorepository between April 12, 2020, and May 28, 2020, from community or academic outpatient or inpatient settings. Demographic and clinical data at presentation to care were from automatic and manual chart extractions. Predictors of enrollment and biospecimen donation were assessed with Poisson regression models.

Results

Among 457 individuals approached, 214 (47%) enrolled in the biorepository. A COVID-19 epidemiologic risk factor was recorded for 53%, and 15% lived in a US Centers for Disease Control and Prevention-defined COVID-19 hotspot. Individuals living in a COVID-19 hotspot (relative risk (RR) 2.4 [95% confidence interval (CI): 1.8–3.2]), with symptoms at presentation (RR 1.8 [95% CI: 1.2–2.7]), or admitted to hospital (RR 1.8 [95% CI: 1.2–2.8]) were more likely to enroll. Seventy-nine percent of enrollees donated any biospecimen, including 97 nasopharyngeal swabs, 119 oropharyngeal swabs, and 105 blood, 16 urine, and 16 stool specimens, respectively. Age, sex, race, ethnicity, and neighborhood-level socioeconomic status based on zip code did not predict enrollment or biospecimen donation.

Conclusions

While fewer than half of individuals approached consented to participate in the pediatric biorepository, enrollment appeared to be representative of children affected by the pandemic. Living in a COVID-19 hotspot, symptoms at presentation to care and hospital admission predicted biorepository enrollment. Once enrolled, most individuals donated a biospecimen.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03185-6.

Zonulin Antagonist, Larazotide (AT1001), As an Adjuvant Treatment for Multisystem Inflammatory Syndrome in Children: A Case Series

OBJECTIVES:

A recent study suggests that Multisystem Inflammatory Syndrome in Children (MIS-C) is triggered by gastrointestinal breach of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral particles from the gut lumen into systemic circulation. The virus remains in the gut weeks to months after respiratory infection, causing zonulin release from the intestinal epithelial cells. Zonulin loosens tight junctions, permitting trafficking of highly inflammatory viral particles into circulation. Current MIS-C treatments target the subsequent immune hyperactivation, not the causative loss of mucosal barrier integrity. Larazotide, a zonulin inhibitor, prevents breakdown of tight junctions, limiting antigen trafficking.

DESIGN:

Children with MIS-C were treated with larazotide as an adjuvant to steroid/intravenous immunoglobulin therapy. Clinical outcomes, SARS-CoV-2 antigenemia, and cytokine profiles are reported. Outcomes were compared with children with MIS-C receiving steroids and/or IVIG therapy alone.

PATIENTS:

Four children with MIS-C, ages 3–17 years, were enrolled.

INTERVENTIONS:

Patients were treated with open label larazotide 10 mcg/kg (maximum 500 mcg/dose) orally four times daily for 21 days.

MEASUREMENTS AND MAIN RESULTS:

All four patients tolerated larazotide without adverse effects and displayed reduction in Spike antigenemia to undetectable levels. When compared with 22 children with MIS-C receiving steroids and/or intravenous immunoglobulin therapy alone, larazotide-treated patients reported significantly improved time to resolution of gastrointestinal symptoms (p = 0.03), and time to clearance of Spike antigenemia (p = 0.04), plus a trend towards shorter length of stay.

CONCLUSIONS:

Larazotide appears safe and well-tolerated and may offer potential benefit as an adjuvant to immune-targeted therapies. Expansion of clinical trials is urgently needed to ascertain the clinical impact of larazotide on MIS-C.

Durability and cross-reactivity of SARS-CoV-2 mRNA vaccine in adolescent children

Emergent SARS-CoV-2 variants and waning humoral immunity in vaccinated individuals have resulted in increased infections and hospitalizations. Children are not spared from infection nor complications of COVID-19, and the recent recommendation for boosters in individuals ages 12 years or older calls for broader understanding of the adolescent immune profile after mRNA vaccination. We tested the durability and cross-reactivity of anti-SARS-CoV-2 serologic responses over a six-month time course in vaccinated adolescents against the SARS-CoV-2 wild type and Omicron antigens. Serum from 77 adolescents showed that anti-Spike antibodies wane significantly over 6 months. After completion of a two-vaccine series, cross-reactivity against Omicron-specific receptor-binding domain (RBD) was seen. Evidence of waning mRNA-induced vaccine immunity underscores vulnerabilities in long-term pediatric protection against SARS-CoV-2 infection, while cross-reactivity highlights the additional benefits of vaccination. Characterization of adolescent immune signatures post-vaccination will inform guidance on vaccine platforms and timelines, and ultimately optimize immunoprotection of children.

Neutrophil Profiles of Pediatric COVID-19 and Multisystem Inflammatory Syndrome in Children

Multisystem Inflammatory Syndrome in Children (MIS-C) is a delayed-onset, COVID-19-related hyperinflammatory systemic illness characterized by SARS-CoV-2 antigenemia, cytokine storm and immune dysregulation; however, the role of the neutrophil has yet to be defined. In adults with severe COVID-19, neutrophil activation has been shown to be central to overactive inflammatory responses and complications. Thus, we sought to define neutrophil activation in children with MIS-C and acute COVID-19. We collected samples from 141 children: 31 cases of MIS-C, 43 cases of acute pediatric COVID-19, and 67 pediatric controls. We found that MIS-C neutrophils display a granulocytic myeloid-derived suppressor cell (G-MDSC) signature with highly altered metabolism, which is markedly different than the neutrophil interferon-stimulated gene (ISG) response observed in pediatric patients during acute SARS-CoV-2 infection. Moreover, we identified signatures of neutrophil activation and degranulation with high levels of spontaneous neutrophil extracellular trap (NET) formation in neutrophils isolated from fresh whole blood of MIS-C patients. Mechanistically, we determined that SARS-CoV-2 immune complexes are sufficient to trigger NETosis. Overall, our findings suggest that the hyperinflammatory presentation of MIS-C could be mechanistically linked to persistent SARS-CoV-2 antigenemia through uncontrolled neutrophil activation and NET release in the vasculature.

ONE SENTENCE SUMMARY

Circulating SARS-CoV-2 antigen:antibody immune complexes in Multisystem Inflammatory Syndrome in Children (MIS-C) drive hyperinflammatory and coagulopathic neutrophil extracellular trap (NET) formation and neutrophil activation pathways, providing insight into disease pathology and establishing a divergence from neutrophil signaling seen in acute pediatric COVID-19.

Pandemic Response Requires Research Samples: A U.S. Safety-Net Hospital's Experience and Call for National Action

Biorepositories provide a critical resource for gaining knowledge of emerging infectious diseases and offer a mechanism to rapidly respond to outbreaks; the emergence of the novel coronavirus, SARS-CoV-2, has proved their importance. During the COVID-19 pandemic, the absence of centralized, national biorepository efforts meant that the onus fell on individual institutions to establish sample repositories. As a safety-net hospital, Boston Medical Center (BMC) recognized the importance of creating a COVID-19 biorepository to both support critical science at BMC and ensure representation in research for its urban patient population, most of whom are from underserved communities. This article offers a realistic overview of the authors' experience in establishing this biorepository at the onset of the COVID-19 pandemic during the height of the first surge of cases in Boston, Massachusetts, with the hope that the challenges and solutions described are useful to other institutions. Going forward, funders, policymakers, and infectious disease and public health communities must support biorepository implementation as an essential element of future pandemic preparedness.

Virologic features of SARS-CoV-2 infection in children

BACKGROUND

Data on pediatric COVID-19 has lagged behind adults throughout the pandemic. An understanding of SARS-CoV-2 viral dynamics in children would enable data-driven public health guidance.

METHODS

Respiratory swabs were collected from children with COVID-19. Viral load was quantified by RT-PCR; viral culture was assessed by direct observation of cytopathic effects and semiquantitative viral titers. Correlations with age, symptom duration, and disease severity were analyzed. SARS-CoV-2 whole genome sequences were compared with contemporaneous sequences.

RESULTS

110 children with COVID-19 (median age 10 years, range 2 weeks-21 years) were included in this study. Age did not impact SARS-CoV-2 viral load. Children were most infectious within the first five days of illness, and severe disease did not correlate with increased viral loads. Pediatric SARS-CoV-2 sequences were representative of those in the community and novel variants were identified.

CONCLUSIONS

Symptomatic and asymptomatic children can carry high quantities of live, replicating SARS-CoV-2, creating a potential reservoir for transmission and evolution of genetic variants. As guidance around social distancing and masking evolves following vaccine uptake in older populations, a clear understanding of SARS-CoV-2 infection dynamics in children is critical for rational development of public health policies and vaccination strategies to mitigate the impact of COVID-19.

COVID-19 Pediatric Dermatology

Children are a unique subset of patients in relation to the COVID-19 pandemic, often presenting asymptomatically, mildly, or atypically. Manifestations of the skin may be a primary (or the only) presenting sign. Recognizing cutaneous manifestations of COVID-19 in the pediatric population is important to guiding precautions, testing, and management for patients and close contacts. Whereas some dermatologic signs in children overlap with those in adults, other skin findings are reported with higher frequency in children and may be clues to multisystemic sequelae. This article describes presentation, pathophysiologic theories, and management strategies for cutaneous manifestations of COVID-19 in children.

Virologic features of SARS-CoV-2 infection in children

BACKGROUND

Data on pediatric COVID-19 has lagged behind adults throughout the pandemic. An understanding of SARS-CoV-2 viral dynamics in children would enable data-driven public health guidance.

METHODS

Respiratory swabs were collected from children with COVID-19. Viral load was quantified by RT-PCR; viral culture was assessed by direct observation of cytopathic effects and semiquantitative viral titers. Correlations with age, symptom duration, and disease severity were analyzed. SARS-CoV-2 whole genome sequences were compared with contemporaneous sequences.

RESULTS

110 children with COVID-19 (median age 10 years, range 2 weeks-21 years) were included in this study. Age did not impact SARS-CoV-2 viral load. Children were most infectious within the first five days of illness, and severe disease did not correlate with increased viral loads. Pediatric SARS-CoV-2 sequences were representative of those in the community and novel variants were identified.

CONCLUSIONS

Symptomatic and asymptomatic children can carry high quantities of live, replicating SARS-CoV-2, creating a potential reservoir for transmission and evolution of genetic variants. As guidance around social distancing and masking evolves following vaccine uptake in older populations, a clear understanding of SARS-CoV-2 infection dynamics in children is critical for rational development of public health policies and vaccination strategies to mitigate the impact of COVID-19.

Multisystem inflammatory syndrome in children is driven by zonulin-dependent loss of gut mucosal barrier

BACKGROUNDWeeks after SARS-CoV-2 infection or exposure, some children develop a severe, life-threatening illness called multisystem inflammatory syndrome in children (MIS-C). Gastrointestinal (GI) symptoms are common in patients with MIS-C, and a severe hyperinflammatory response ensues with potential for cardiac complications. The cause of MIS-C has not been identified to date.METHODSHere, we analyzed biospecimens from 100 children: 19 with MIS-C, 26 with acute COVID-19, and 55 controls. Stools were assessed for SARS-CoV-2 by reverse transcription PCR (RT-PCR), and plasma was examined for markers of breakdown of mucosal barrier integrity, including zonulin. Ultrasensitive antigen detection was used to probe for SARS-CoV-2 antigenemia in plasma, and immune responses were characterized. As a proof of concept, we treated a patient with MIS-C with larazotide, a zonulin antagonist, and monitored the effect on antigenemia and the patient's clinical response.RESULTSWe showed that in children with MIS-C, a prolonged presence of SARS-CoV-2 in the GI tract led to the release of zonulin, a biomarker of intestinal permeability, with subsequent trafficking of SARS-CoV-2 antigens into the bloodstream, leading to hyperinflammation. The patient with MIS-C treated with larazotide had a coinciding decrease in plasma SARS-CoV-2 spike antigen levels and inflammatory markers and a resultant clinical improvement above that achieved with currently available treatments.CONCLUSIONThese mechanistic data on MIS-C pathogenesis provide insight into targets for diagnosing, treating, and preventing MIS-C, which are urgently needed for this increasingly common severe COVID-19-related disease in children.

A longitudinal SARS-CoV-2 biorepository for COVID-19 survivors with and without post-acute sequelae

BACKGROUND

SARS-CoV-2 has swept across the globe, causing millions of deaths worldwide. Though most survive, many experience symptoms of COVID-19 for months after acute infection. Successful prevention and treatment of acute COVID-19 infection and its associated sequelae is dependent on in-depth knowledge of viral pathology across the spectrum of patient phenotypes and physiologic responses. Longitudinal biobanking provides a valuable resource of clinically integrated, easily accessed, and quality-controlled samples for researchers to study differential multi-organ system responses to SARS-CoV-2 infection, post-acute sequelae of COVID-19 (PASC), and vaccination.

METHODS

Adults with a history of a positive SARS-CoV-2 nasopharyngeal PCR are actively recruited from the community or hospital settings to enroll in the Northern Colorado SARS-CoV-2 Biorepository (NoCo-COBIO). Blood, saliva, stool, nasopharyngeal specimens, and extensive clinical and demographic data are collected at 4 time points over 6 months. Patients are assessed for PASC during longitudinal follow-up by physician led symptom questionnaires and physical exams. This clinical trial registration is NCT04603677 .

RESULTS

We have enrolled and collected samples from 119 adults since July 2020, with 66% follow-up rate. Forty-nine percent of participants assessed with a symptom surveillance questionnaire (N = 37 of 75) had PASC at any time during follow-up (up to 8 months post infection). Ninety-three percent of hospitalized participants developed PASC, while 23% of those not requiring hospitalization developed PASC. At 90-174 days post SARS-CoV-2 diagnosis, 67% of all participants had persistent symptoms (N = 37 of 55), and 85% percent of participants who required hospitalization during initial infection (N = 20) still had symptoms. The most common symptoms reported after 15 days of infection were fatigue, loss of smell, loss of taste, exercise intolerance, and cognitive dysfunction.

CONCLUSIONS

Patients who were hospitalized for COVID-19 were significantly more likely to have PASC than those not requiring hospitalization, however 23% of patients who were not hospitalized also developed PASC. This patient-matched, multi-matrix, longitudinal biorepository from COVID-19 survivors with and without PASC will allow for current and future research to better understand the pathophysiology of disease and to identify targeted interventions to reduce risk for PASC. Registered 27 October 2020 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04603677 .

Global biochemical analysis of plasma, serum and whole blood collected using various anticoagulant additives

Introduction

Analysis of blood for the evaluation of clinically relevant biomarkers requires precise collection and sample handling by phlebotomists and laboratory staff. An important consideration for the clinical application of metabolomics are the different anticoagulants utilized for sample collection. Most studies that have characterized differences in metabolite levels in various blood collection tubes have focused on single analytes. We define analyte levels on a global metabolomics platform following blood sampling using five different, but commonly used, clinical laboratory blood collection tubes (i.e., plasma anticoagulated with either EDTA, lithium heparin or sodium citrate, along with no additive (serum), and EDTA anticoagulated whole blood).

Methods

Using an untargeted metabolomics platform we analyzed five sample types after all had been collected and stored at -80°C. The biochemical composition was determined and differences between the samples established using matched-pair t-tests.

Results

We identified 1,117 biochemicals across all samples and detected a mean of 1,036 in the sample groups. Compared to the levels of metabolites in EDTA plasma, the number of biochemicals present at statistically significant different levels (p<0.05) ranged from 452 (serum) to 917 (whole blood). Several metabolites linked to screening assays for rare diseases including acylcarnitines, bilirubin and heme metabolites, nucleosides, and redox balance metabolites varied significantly across the sample collection types.

Conclusions

Our study highlights the widespread effects and importance of using consistent additives for assessing small molecule levels in clinical metabolomics. The biochemistry that occurs during the blood collection process creates a reproducible signal that can identify specimens collected with different anticoagulants in metabolomic studies.

Impact statement

In this manuscript, normal/healthy donors had peripheral blood collected using multiple anticoagulants as well as serum during a fasted blood draw. Global metabolomics is a new technology being utilized to draw clinical conclusions and we interrogated the effects of different anticoagulants on the levels of biochemicals from each of the donors. Characterizing the effects of the anticoagulants on biochemical levels will help researchers leverage the information using global metabolomics in order to make conclusions regarding important disease biomarkers.

Biobanking for COVID-19 research

BACKGROUND

Biobanks are imperative infrastructures, particularly during outbreaks, when there is an obligation to acquire and share knowledge as quick as possible to allow for implementation of science-based preventive, diagnostic, prognostic and therapeutic strategies.

METHODS

We established a COVID-19 biobank with the aim of collecting high-quality and well-annotated human biospecimens, in the effort to understand the pathogenic mechanisms underlying COVID-19 and identify therapeutic targets (COVID-BioB, NCT04318366). Here we describe our experience and briefly review the characteristics of the biobanks for COVID-19 that have been so far established.

RESULTS

A total of 46,677 samples have been collected from 913 participants (63.3% males, median [IQR] age 62.2 [51.2 - 74.0] years) since the beginning of the program. Most patients (66.9%) had been admitted to hospital for COVID-19, with a median length of stay of 15.0 (9.0 - 27.0) days. A minority of patients (13.3% of the total) had been admitted for other reasons and subsequently tested positive for SARS-CoV-2. The remainder were managed at home after being seen at the Emergency Department.

CONCLUSIONS

Having a solid research infrastructure already in place, along with flexibility and adaptability to new requirements, allowed for the quick building of a COVID-19 biobank that will help expand and share the knowledge of SARS-CoV-2.