Thrombotic complications in children with Coronavirus disease 2019 and Multisystem Inflammatory Syndrome of Childhood

An Update on Multi-System Inflammatory Syndrome in Children

PURPOSE

To summarize the latest research on the epidemiology, pathogenesis, diagnosis, and treatment of multisystem inflammatory syndrome in children (MIS-C).

RECENT FINDINGS

The epidemiology of MIS-C has been dynamic since its initial description. The pathogenesis remains poorly understood. Case definitions of MIS-C have evolved over time, and practice patterns for treating MIS-C are variable with generally positive long-term outcomes yet persistent changes noted. MIS-C has become less prevalent and less severe over time, yet racial and ethnic disparities persist, and vaccination against COVID-19 is highly effective in preventing this disease. The link between acute infection and subsequent inflammation is not well understood, with growing evidence describing its immunologic signature. Newer case definitions require excluding other inflammatory conditions, including Kawasaki Disease (KD), before diagnosing MIS-C. Corticosteroid monotherapy may be non-inferior to IVIg alone or combination IVIg plus corticosteroids for initial treatment, distinguishing the approaches to MIS-C and KD. A wide range of biologic therapies have been employed for rescue therapy with general success and no clear benefit of one over another. Despite reports of a high rate of coronary artery abnormality regression and resolution of heart failure, long-term studies suggest persistent changes to cardiac function. The long-term effects of MIS-C continue to be active areas of research.

Aortoiliac arterial thrombosis and renal artery stenosis in a patient with neonatal multisystem inflammatory syndrome: a case report and review of literature

Background

Multisystem inflammatory syndrome in neonates (MIS-N) is a rare condition thought to be associated with prenatal exposure to maternal severe acute respiratory syndrome coronavirus 2 infection. This immune-mediated hyperinflammation has been described in neonates with multiorgan dysfunction, including cardiopulmonary, encephalopathy, coagulopathy, and vascular complications. However, renovascular complications in MIS-N are rare. Here, we present a case with aortoiliac arterial thrombosis and renovascular stenosis in MIS-N.

Case presentation

A 2-day-old, full-term, male neonate presented with fever, respiratory failure, hypotensive shock, and elevated inflammatory markers. He was transferred to our neonatal intensive care unit for comprehensive monitoring and treated with antibiotics for early-onset neonatal sepsis. However, his clinical condition deteriorated. His mother reported a history of severe acute respiratory syndrome coronavirus 2 infection during the late second trimester. He was diagnosed with MIS-N based on the fulfillment of the diagnostic criteria for multiorgan involvement and laboratory findings. He responded to intravenous immunoglobulin, corticosteroids, and aspirin. However, he later developed significant hypertension, which was associated with aortoiliac arterial thrombosis and right renal artery stenosis. An elevated ferritin level was observed. The ongoing inflammatory condition was considered, and corticosteroids were restarted along with treatment for documented thrombosis using enoxaparin and aspirin. After treatment, partial resolution of aortoiliac arterial thrombus was observed. However, narrowing of the proximal part of right renal artery persisted, and blood pressure remained difficult to control, requiring multiple antihypertensive agents. Finally, the patient underwent percutaneous transluminal balloon angioplasty to control hypertension.

Conclusion

Our case revealed the clinical course of MIS-N with renovascular complications. The condition's hyperinflammatory state may have played a pathophysiological role in the development of this life-threatening complication. Although there is an increased risk of bleeding in MIS-N, thromboprophylaxis should be considered in high-risk patients. An early multidisciplinary approach is recommended to ensure prompt diagnosis and improve outcomes.

Prospective Randomized Pilot Study Comparing Bivalirudin Versus Heparin in Neonatal and Pediatric Extracorporeal Membrane Oxygenation

OBJECTIVES

To test feasibility of a randomized controlled trial (RCT) with an endpoint of time at goal anticoagulation in children on extracorporeal membrane oxygenation (ECMO) randomized to receive bivalirudin vs. unfractionated heparin.

DESIGN

Open-label pilot RCT (NCT03318393) carried out 2018-2021.

SETTING

Single-center quaternary U.S. pediatric hospital.

PATIENTS

Children 0 days to younger than 18 years old supported with ECMO in the PICU or cardiovascular ICU.

INTERVENTIONS

Randomization to bivalirudin vs. unfractionated heparin while on ECMO.

MEASUREMENTS AND MAIN RESULTS

Sixteen patients were randomized to bivalirudin, and 14 patients were randomized to heparin. There was no difference in the primary outcome, time spent at goal anticoagulation, for patients randomized to bivalirudin compared with those randomized to heparin. While hemorrhagic complications were similar between study groups, thrombotic complications were higher with six of 16 patients in the bivalirudin group having one or more circuit changes compared with 0 of 14 patients in heparin group (mean difference, 37.5% [95% CI, 8.7-61.4%]; p = 0.02). Patients in the bivalirudin group received less packed RBC transfusions vs. those receiving heparin (median [interquartile range], 6.3 mL/kg/d [2.5-8.4 mL/kg/d] vs. 12.2 mL/kg/d [5.5-14.5 mL/kg/d]; p = 0.02).

CONCLUSIONS

In this single-center pilot RCT carried out 2018-2021, we found that the test of anticoagulation therapy of bivalirudin vs. heparin during ECMO was feasible. Larger multicenter studies are required to further assess the safety and efficacy of bivalirudin for pediatric ECMO.

Trends in the Diagnosis of Pediatric Venous Thromboembolism and Arterial Ischemic Stroke during the COVID-19 Pandemic: An Administrative Database Study

OBJECTIVE

To investigate trends in the diagnosis of venous thromboembolism (VTE) and arterial ischemic stroke (AIS), and examine the use of pharmacological thromboprophylaxis during the COVID-19 pandemic.

STUDY DESIGN

This retrospective cohort study used the Pediatric Health Information Systems database to investigate patients admitted to a participating hospital between January 1, 2018, and December 31, 2021. International Classification of Diseases, 10th edition codes were used to identify VTE, AIS, and COVID-19. Pharmacy billing codes were used to investigate pharmacological thromboprophylaxis use.

RESULTS

1 759 701 unique patients underwent 2 234 135 inpatient admissions. Rate of VTE increased from 84 cases per 10 000 admissions in 2018-2019 to 108 cases per 10 000 admissions in 2020-2021, representing a 28.6% increase (P < .001). In contrast, the rate of AIS remained stable through the study period. When compared with 2018-2019, children diagnosed with VTE during 2020-2021 had longer hospitalizations and were more likely to be admitted to the intensive care unit. When analysis was limited to 2020-2021, a diagnosis code of COVID-19 was associated with a 1.35-fold (95% CI: 1.24-1.45) increase in the odds of VTE diagnosis, but not AIS. Use of pharmacologic thromboprophylaxis increased from 1.5% of hospitalizations in 2018-2019 to 3.0% of hospitalizations in 2020-2021 (P < .001). When evaluating thromboprophylaxis during 2020-2021, a diagnosis code for COVID-19 was associated with an 11-fold (95% CI: 10.86-11.49; P < .001) increase in the utilization of pharmacological thromboprophylaxis.

CONCLUSIONS

This study found an increase in the rate of VTE among hospitalized children during the pandemic. A diagnosis of COVID-19 was associated with a modest increase in odds of VTE diagnosis, which occurred despite increased use of pharmacological thromboprophylaxis.

Proteomic profiling reveals diagnostic signatures and pathogenic insights in multisystem inflammatory syndrome in children

Multisystem inflammatory syndrome in children (MIS-C) is a severe disease that emerged during the COVID-19 pandemic. Although recognized as an immune-mediated condition, the pathogenesis remains unresolved. Furthermore, the absence of a diagnostic test can lead to delayed immunotherapy. Using state-of-the-art mass-spectrometry proteomics, assisted by artificial intelligence (AI), we aimed to identify a diagnostic signature for MIS-C and to gain insights into disease mechanisms. We identified a highly specific 4-protein diagnostic signature in children with MIS-C. Furthermore, we identified seven clusters that differed between MIS-C and controls, indicating an interplay between apolipoproteins, immune response proteins, coagulation factors, platelet function, and the complement cascade. These intricate protein patterns indicated MIS-C as an immunometabolic condition with global hypercoagulability. Our findings emphasize the potential of AI-assisted proteomics as a powerful and unbiased tool for assessing disease pathogenesis and suggesting avenues for future interventions and impact on pediatric disease trajectories through early diagnosis.

Antiplatelet therapy prior to COVID-19 infection impacts on patients mortality: a propensity score-matched cohort study

One of the major pathomechanisms of COVID-19 is the interplay of hyperinflammation and disruptions in coagulation processes, involving thrombocytes. Antiplatelet therapy (AP) by anti-inflammatory effect and inhibition of platelet aggregation may affect these pathways. The aim of this study was to investigate if AP has an impact on the in-hospital course and medium-term outcomes in hospitalized COVID-19 patients. The study population (2170 COVID-19 patients: mean ± SD age 60 ± 19 years old, 50% male) was divided into a group of 274 patients receiving any AP prior to COVID-19 infection (AP group), and after propensity score matching, a group of 274 patients without previous AP (non-AP group). Patients from the AP group were less frequently hospitalized in the intensive care unit: 9% vs. 15%, 0.55 (0.33-0.94), developed less often shock: 9% vs. 15%, 0.56 (0.33-0.96), and required less aggressive forms of therapy. The AP group had more coronary revascularizations: 5% vs. 1%, 3.48 (2.19-5.55) and strokes/TIA: 5% vs. 1%, 3.63 (1.18-11.2). The bleeding rate was comparable: 7% vs. 7%, 1.06 (0.54-2.06). The patients from the AP group had lower 3-month mortality: 31% vs. 39%, 0.69 (0.51-0.93) and didn't differ significantly in 6-month mortality: 34% vs. 41%, 0.79 (0.60-1.04). When analyzing the subgroup with a history of myocardial infarction and/or coronary revascularization and/or previous stroke/transient ischemic attack and/or peripheral artery disease, AP had a beneficial effect on both 3-month: 37% vs. 56%, 0.58 (0.40-0.86) and 6-month mortality: 42% vs. 57%, 0.63 (0.44-0.92). Moreover, the favourable effect was highly noticeable in this subgroup where acetylsalicylic acid was continued during hospitalization with reduction of in-hospital: 19% vs. 43%, 0.31 (0.15-0.67), 3-month: 30% vs. 54%, 044 (0.26-0.75) and 6-month mortality: 33% vs. 54%, 0.49 (0.29-0.82) when confronted with the subgroup who had acetylsalicylic acid suspension during hospitalization. The AP may have a beneficial impact on hospital course and mortality in COVID-19 and shouldn't be discontinued, especially in high-risk patients.

Ischemic Stroke in the Course of COVID-19 in a 16-Year-Old Boy

The SARS-CoV-2 virus that causes COVID-19 disease is still evolving and, despite the end of the acute phase of the pandemic, still poses a risk to public health. One of the very rare complications, occurring in less than 1% of children, is multisystem inflammatory syndrome in children (MISC). Due to the risk of thromboembolic complications as well as cardiac problems, MISC carries a number of life-threatening complications. We report a case of a 16-year-old boy who was hospitalized due to general weakness, fever, conjunctivitis, vomiting and diarrhoea. In view of the mother's positive result of the SARS-CoV-2 test, the teenager underwent numerous laboratory tests. Taking into account the critical condition of the patient, anticoagulant and antipyretic treatment, steroids and IVIG were added. During hospitalisation, alarming symptoms occurred, including dysarthria, drooping corner of the mouth and muscle weakness on the right side. The magnetic resonance imaging showed changes characteristic of ischemic stroke. Further studies are needed to assess possible thrombotic complications in children after SARS-CoV-2 infection, and specialists should be more vigilant in paediatric patients presenting with such symptoms.

Thrombosis in Multisystem Inflammatory Syndrome Associated with COVID-19 in Children: Retrospective Cohort Study Analysis and Review of the Literature

Background: The causative agent of the new coronavirus infection SARS-CoV-2 has unique properties causing hyperinflammatory syndrome and cytokine storm, as well as widespread endotheliitis and thrombotic microangiopathy, initially detected in the lungs of adult patients who died from a severe form of the disease. Venous and arterial thrombosis in adults were identified as common causes of severe complications and deaths in new coronavirus infections. There are very few reports of thrombotic events in children with COVID-19 in the literature. Methods: We conducted a retrospective analysis of the histories of 60 patients in the Irkutsk Regional Children's Clinical Hospital from November 2020 to November 2022 with a MIS-C diagnosis established according to WHO criteria, of which 8 (13.3%) were diagnosed with venous and/or arterial thrombosis, confirmed by laboratory and ultrasound and/or X-ray methods. Results: The average age of children with thrombosis (Me) was 7.5 years (min 4 months, max 17 years), with a M:F ratio of 3.0. Venous thrombosis was detected in six of the eight patients, including in the deep veins of the lower extremities in four. Pulmonary embolism occurred in two (one of them was fatal), and cerebral venous sinus thrombosis and thrombosis of the branches of the upper and lower vena cava were found in one patient. Extensive bilateral stroke due to thrombosis of the large cerebral arteries occurred in two patients, including one in combination with distal gangrene. Secondary thrombotic renal microangiopathy took place in three of the eight patients. Among these three, atypical HUS was diagnosed in one case. Multiple thrombosis involving the venous and arterial bed was detected in four of the eight patients. High levels of D-dimer, thrombocytopenia, increased NT-proBNP, cerebral coma, and aseptic meningitis were the events most often associated with thrombosis. All patients received immunomodulatory therapy (immunoglobulin, dexamethasone/methylprednisolone), pathogenetic therapy for multiorgan failure, anticoagulant therapy with heparin/LMWH, and acetylsalicylic acid. Biologics were used in two patients. Conclusions: The main predictors of thrombosis in children with MIS-C were increased D-dimer, thrombocytopenia, hospitalization in the ICU, and noncardiogenic pulmonary edema. Thrombosis of the deep veins of the lower extremities, large cerebral arteries, and secondary thrombotic microangiopathy was common. There was a single death (12.5% of the eight patients), associated with PE.