multisystem inflammatory syndrome – American ME and CFS Society

Navigating the Spectrum of Two Pediatric COVID-19 Complications: Multi-System Inflammatory Syndrome in Children and Post-Acute Sequelae of SARS-CoV-2 Infection

Abstract:

Purpose: This review summarizes the current scope of understanding associated with two common post-infectious complications associated with COVID-19 infection: Multi-System Inflammatory Syndrome in Children (MIS-C) and Post-Acute Sequelae of SARS-CoV-2 infection (PASC). It identifies current gaps in the knowledge and issues that may limit the ability to fill these gaps. This review provides a framework to drive continued research.

Methods: A comprehensive review of the current literature was performed, identifying seminal articles describing the emergence of MIS-C and PASC, and works from the literature focused on the clinical implications and pathophysiologic understanding of these disorders.

Findings: Although pediatric patients experienced few severe cases of acute COVID-19 infection, the burden of disease from post-infectious sequelae is substantial. Mortality is low, but morbidity is significant. There are still numerous unknowns about the pathophysiology of both MIS-C and PASC; however, with widespread immunity developing after increased vaccination and prior infection, it may be difficult to perform adequate prospective studies to answer pathophysiologic questions. Long-term sequalae of MIS-C seem to be minimal whereas, by definition, PASC is an ongoing problem and may be severe.

Implications: The rapid sharing of information regarding novel conditions such as MIS-C and PASC are key to interventions related to future post-infectious sequelae outside of those stemming from COVID-19. Although MIS-C seems unlikely to return as a clinical condition in substantial numbers, there is still significant learning that can be gleaned from existing patients about general aspects of epidemiology, equity, and pathophysiology. There is significant morbidity associated with PASC and additional resources need to be dedicated to determining appropriate and effective therapies moving forward.

Source: Parzen-Johnson S, Katz BZ. Navigating the Spectrum of Two Pediatric COVID-19 Complications: Multi-System Inflammatory Syndrome in Children and Post-Acute Sequelae of SARS-CoV-2 Infection. J Clin Med. 2024 Feb 18;13(4):1147. doi: 10.3390/jcm13041147. PMID: 38398460. https://www.mdpi.com/2077-0383/13/4/1147 (Full text)

Multisystem inflammatory syndrome in children (MIS-C): Implications for long COVID

Abstract:

The COVID-19 pandemic caused by the coronavirus 2 of the severe acute respiratory syndrome (SARS-CoV-2) has significantly affected people around the world, leading to substantial morbidity and mortality. Although the pandemic has affected people of all ages, there is increasing evidence that children are less susceptible to SARS-CoV-2 infection and are more likely to experience milder symptoms than adults. However, children with COVID-19 can still develop serious complications, such as multisystem inflammatory syndrome in children (MIS-C).

This narrative review of the literature provides an overview of the epidemiology and immune pathology of SARS-CoV-2 infection and MIS-C in children. The review also examines the genetics of COVID-19 and MIS-C in children, including the genetic factors that can influence the susceptibility and severity of the diseases and their implications for personalized medicine and vaccination strategies.

By examining current evidence and insights from the literature, this review aims to contribute to the development of effective prevention and treatment strategies for COVID-19, MIS-C, and long COVID syndromes in children.

Source: Constantin T, Pék T, Horváth Z, Garan D, Szabó AJ. Multisystem inflammatory syndrome in children (MIS-C): Implications for long COVID. Inflammopharmacology. 2023 Jul 17. doi: 10.1007/s10787-023-01272-3. Epub ahead of print. PMID: 37460909. https://link.springer.com/article/10.1007/s10787-023-01272-3 (Full text)

Partners in crime: Autoantibodies complicit in COVID-19 pathogenesis

Abstract:

Autoantibodies (AABs) play a critical role in the pathogenesis of autoimmune diseases (AIDs) and serve as a diagnostic and prognostic tool in assessing these complex disorders. Viral infections have long been recognized as a principal environmental factor affecting the production of AABs and the development of autoimmunity. COVID-19 has primarily been considered a hyperinflammatory syndrome triggered by a cytokine storm. In the following, the role of maladaptive B cell response and AABs became more apparent in COVID-19 pathogenesis.

The current review will primarily focus on the role of extrafollicular B cell response, Toll-like receptor-7 (TLR-7) activation, and neutrophil extracellular traps (NETs) formation in the development of AABs following SARS-CoV-2 infection. In the following, this review will clarify how these AABs dysregulate immune response to SARS-CoV-2 by disrupting cytokine function and triggering neutrophil hyper-reactivity.

Finally, the pathologic effects of these AABs will be further described in COVID-19 associate clinical manifestations, including venous and arterial thrombosis, a multisystem inflammatory syndrome in children (MIS-C), acute respiratory distress syndrome (ARDS), and recently described post-acute sequelae of COVID-19 (PASC) or long-COVID.

Source: Taghadosi M, Safarzadeh E, Asgarzadeh A, Roghani SA, Shamsi A, Jalili C, Assar S, Soufivand P, Pournazari M, Feizollahi P, Nicknam MH, Asghariazar V, Vaziri S, Shahriari H, Mohammadi A. Partners in crime: Autoantibodies complicit in COVID-19 pathogenesis. Rev Med Virol. 2022 Dec 5:e2412. doi: 10.1002/rmv.2412. Epub ahead of print. PMID: 36471421. https://pubmed.ncbi.nlm.nih.gov/36471421/ https://www.researchgate.net/publication/366031618_Partners_in_crime_Autoantibodies_complicit_in_COVID-19_pathogenesis (Full text)

Spectrum of SARS-CoV-2-Related Clinical Syndromes in Children: A Year in the Life

Abstract:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a wide pediatric clinical spectrum. Initial reports suggested that children had milder symptoms compared with adults; then diagnosis of multisystem inflammatory syndrome in children (MIS-C) emerged. We performed a retrospective cohort study of hospitalized patients at a children’s hospital over 1 year. Our objectives were to study the demographic and clinical profile of pediatric SARS-CoV-2-associated diagnoses.

Based on the clinical syndrome, patients were classified into coronavirus disease 2019 (COVID-19; non-MIS-C) and MIS-C cohorts. Among those who tested positive, 67% were symptomatic. MIS-C was diagnosed in 24 patients. Both diagnoses were more frequent in Caucasians. Both cohorts had different symptom profiles.

Inflammatory markers were several-fold higher in MIS-C patients. These patients had critical care needs and longer hospital stays. More COVID-19 patients had respiratory complications, while MIS-C cohort saw cardiovascular involvement. Health care awareness of both syndromes is important for early recognition, diagnosis, and prompt treatment.

Source: Khan M, Dang L, Singh H, Dalrymple A, Miller A, Tanios A. Spectrum of SARS-CoV-2-Related Clinical Syndromes in Children: A Year in the Life. Clin Pediatr (Phila). 2021 Dec 3:99228211064655. doi: 10.1177/00099228211064655. Epub ahead of print. PMID: 34859714. https://pubmed.ncbi.nlm.nih.gov/34859714/