Review Multisystem inflammatory syndrome in children (MIS-C): Implications for long COVID, 2023, Constantin et al

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.

Open access: https://link.springer.com/article/10.1007/s10787-023-01272-3

 

The part about long covid:

Interesting that out of all things the authors think it is the aftereffects of toxic shock syndrome that neuro long covid is strikingly similar to.

 

Both Polybio https://polybio.org/projects/sars-c...-spike-protein-in-pediatric-long-covid-mis-c/ and RECOVER https://classic.clinicaltrials.gov/ct2/show/NCT04588363 seem to be studying MIS-C as well, so there should be more studies on this coming out soon.

 

There is also multisystem inflammatory syndrome in adults (MIS-A). Which appeared to be acknowledged sometime after the announcement of MIS-C.

https://www.cdc.gov/mis/mis-a.html


It would be interesting to know if the two named syndromes are a new phenomenon or if the same mechanism has happened alongside other post-infectious illnesses.

 

For the children, there are a lot of overlaps with Kawasaki disease. I think the coronary artery aneurysms that are a common late effect in KD are not seen as frequently in MIS-C however. [ETA: however may be similar, see next comment]

MIS-C: myths have been debunked, but mysteries remain (2023, Nature Reviews Rheumatology)
Kawasaki disease and MIS-C share a host immune response (2022, Nature Reviews Rheumatology)
A comparison of Kawasaki Disease and multisystem inflammatory syndrome in children (2022, Progress in Pediatric Cardiology)
Multisystem Inflammatory Syndrome in Children and Long COVID: The SARS-CoV-2 Viral Superantigen Hypothesis (2022, Frontiers in Immunology)

See also —

Inborn errors of OAS–RNase L in SARS-CoV-2–related multisystem inflammatory syndrome in children (2023, Science)

 

From Kawasaki disease and MIS-C share a host immune response (2022, Nature Reviews Rheumatology) —

This is summary commentary on An Artificial Intelligence-guided signature reveals the shared host immune response in MIS-C and Kawasaki disease (2022, Nature Communications)

 

Btw, interesting tidbit about the corresponding author, Tamás Constantin, who is a well-known pediatrician here (a rheumatologist):

He streamed a Facebook video very early into long covid, which was a discussion of pediatric long covid with three other pediatricians. I watched it back then and I remember that among other things he talked about how we cannot dismiss the potential psychological effects of the lockdowns, the isolation etc on children and how these very likely contribute to the symptoms. He also mentioned how it is known in medicine that people sometimes feel amplified pain due to some stressful trigger or at least that's how they perceive it. I actually wrote about the video here if anyone is interested.

I criticized this discussion a bit on my Facebook page (I didn't have a website back then) but I also criticized this in a comment below the video (I have no idea if Constantin ever saw it, there were a lot of comments).

So it was nice to read this paper coming from him as the lead author and with even a sentence like this in it: "Research has shown that these long-term COVID symptoms cannot be attributed to any psychological effects of recent social restrictions in place (Borch et al. 2022b)."