A study that sees the Policlinico San Matteo in Pavia at the forefront has identified ‘spy’ markers that “allow us to clarify how, in some genetically predisposed children, a rare complication of Sars-CoV-2 infection can develop. “known as multisystem inflammatory syndrome (Mis-C) and potentially fatal. The work is published in ‘Nature Medicine’ and shows that “a timely intervention, at the first signs of inflammation, with steroids and high-dose immunoglobulins is effective in ‘extinguishing’ the inflammatory storm” and allows “clinical improvement” of the affected children. by Mis-C. The research also helps explain why children with Covid-19 tend to have a milder clinical course than adults.
In these 2 years of pandemic – recall from the Lombard IRCCS – pediatric specialists have repeatedly stressed the difference in response between adults and children to Sars-CoV-2 infection. The majority of pediatric patients presented with mild symptoms. Some, however, 2-6 weeks after the onset of the disease have developed a hyper inflammatory response similar to Kawasaki disease and toxic shock syndrome, precisely defined with the English acronym Mis-C.
Researchers and clinicians at San Matteo had already tried to investigate the reasons linked to such a different clinical course of the disease between adulthood and pediatric age, and the results had been published in ‘Jama Pediatrics’. Now the same experts from San Matteo Pediatrics, led by Gian Luigi Marseglia, have taken part in an international study coordinated by Luigi Daniele Notarangelo, Director of the Immunological Area of the American National Institute of Allergy and Infectious Diseases (Niaid), who in Pavia he graduated and specialized in Pediatrics. Among the first signatories there is a young researcher of Paediatrics Pavia, Riccardo Castagnoli, who has carried out the investigations in the USA. The work involved numerous pediatric centers in Italy, Chile, Israel and the United States.
The authors – report from the Irccs Policlinico San Matteo di Pavia Foundation – have tried to understand the trend of various immune markers of inflammation in children with Covid and in those with Mis-C using a ‘multi-omic’ approach, which through the use of multiple analysis techniques is able to characterize and measure the abnormalities of the immune system that can predict the development of these pathologies. The researchers thus found “substantial differences in the way in which the immune system of children responds to Covid-19, compared to the response observed in adults”.
“Children – it emerged from the investigations – develop innate immune responses more powerful and effective against the virus than adults and this justifies” the fact “that, in most children, Sars-CoV-2 infection is rapidly limited and the disease has a rapidly favorable course “. However, the results also indicated that “in children genetically predisposed to developing Mis-C, the increase in levels of various inflammatory biomarkers is early and uncontrolled and is therefore responsible for the severe clinical manifestations of this complication.”
“The signs and symptoms of Mis-C (fever and multi-organ involvement, especially of the heart) usually appear without warning”, the experts point out, specifying that “to date no clear data indicated who could be most at risk of develop this complication from Covid-19 “.