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Most affected children have had current or recent coronavirus infections, the CDC said.
LOS ANGELES - Researchers at the National Institutes of Health are studying a promising antibody treatment for multisystem inflammatory syndrome in children (MIS-C), most commonly linked to COVID-19 infection.
In a study published on Oct. 15, NIH researchers found that Intravenous immune globulin (IVIG) — a common treatment for MIS-C, worked by depleting inflammatory immune cells which exacerbate the symptoms of MIS-C.
MIS-C is a condition in which different body parts can become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs, according to the NIH.
Symptoms of MIS-C include fever, abdominal pain, vomiting, diarrhea, neck pain, rash, bloodshot eyes and feeling tired.
Cases of the rare syndrome have been linked to COVID-19 and were on the rise in 2020 and earlier this year amid the ongoing COVID-19 pandemic, according to the U.S. Centers for Disease Control and Prevention.
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So far, the only treatment for MIS-C shadows techniques used for treating Kawasaki disease, another rare inflammatory condition that affects children and shares symptoms with MIS-C.
In order to better understand how IVIG works in treating MIS-C, NIH researchers sampled cells before patients received the experimental treatment and analyzed the cells two to six weeks after treatment began.
They found that the immune cells called neutrophils — which typically drive inflammation in the body under the influence of MIS-C — were significantly depleted in patients with both Kawasaki disease and MIS-C after undergoing IVIG treatment.
In March, the NIH launched research efforts to better understand MIS-C, as well as other effects of COVID-19 on children since roughly 13% of total COVID-19 cases in children, report MIS-C.
The effort, called the Collaboration to Assess Risk and Identify Long-term Outcomes for Children with COVID (CARING for Children with COVID), develops and funds studies to investigate why some children are at greater risk for SARS-CoV-2 infection than others, why symptoms vary among children who are infected, and how to identify children at risk for severe illness from SARS-CoV-2 infection.
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"This effort stems from NIH’s commitment to understanding the spectrum of risk that SARS-CoV-2 poses for children and to identifying interventions to improve their short- and long-term health outcomes," NICHD Director and CARING for Children with COVID co-chair Dr. Diana Bianchi said.
The research will focus heavily on cases of MIS-C.
While most children with MIS-C survive, its long-term effects — including fatigue, muscle pain, joint pain and respiratory problems — remain largely unknown.
"While much of the devastation wrought by COVID-19 is on older and vulnerable populations, it is affecting children in ways we are just beginning to understand," said Dr. Gary Gibbons, director of the NHLBI and co-chair of CARING for Children with COVID. "That’s why this research and these networks are so critical."