Children who have previously caught the common cold have coronavirus antibodies that prevent them from developing the hyper-inflammatory condition called MIS-C, new research suggests.
The rare disease is caused by infection with the SARS-CoV-2 coronavirus, the same pathogen responsible for the current COVID-19 pandemic.
Research has found the condition, known as multisystem inflammatory syndrome in children (MIS-C), is different to both COVID-19 and Kawasaki disease.
However, little is known about why some children, roughly a month after being infected with the coronavirus, develop MIS-C symptoms.
Indicators of the disease include a rash, fever and abdominal pain as well as conjunctivitis, a cough and a headache.
Experts at the Karolinska Institutet in Sweden compared healthy children with youngsters suffering from MIS-C and Kawasaki disease.
Blood tests of 13 MIS-C-patients, 28 Kawasaki disease patients and uninfected children revealed the MIS-C cohort lack antibodies against the common cold.
Researchers say it is possible antibodies obtained after infection with the common cold could play a role in controlling the development of MIS-C.
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Experts at the Karolinska Institutet in Sweden compared healthy children with youngsters suffering from MIS-C and Kawsaki disease. Pictured, symptoms of both diseases
Bertie Brown was admitted to Worcestershire Royal hospital this year on his second birthday after developing a fever and rash across his body which is thought to have been MIS-C
The researchers looked for evidence of antibodies to the coronaviruses HKU1 and betacoronavirus 1, both of which cause what we know as the common cold.
Unlike children with Kawasaki disease and children with mild COVID-19, children who developed MIS-C were lacking antibodies to these mild coronaviruses.
Dr Petter Brodin, lead author of the study, told MailOnline there is currently no way to verify the theory that immunity to the common cold via antibodies offers protection against MIS-C, but it appears this may be the case.
'The fact that immunity to common cold coronavirus is usually quite shortlived, and the fact that MIS-C typically affects teenagers, and the finding that MIS-C patients were the only group lacking these common cold coronavirus-antibodies, all suggest it is possible that having such antibodies might protect against MIS-C,' he said.
He believes common cold CoV antibodies and the memory B-cells that produce them may recognise SARS-CoV-2 virus and bind to it.
'Such events will give the immune system a head start in defending against the virus and might enable a more efficient antibody response that directly zooms in on the right parts of the new virus to neutralise it,' he adds.
MIS-C is a form of toxic shock syndrome which causes the body's immune system to attack its own organs. It is believed to be caused by infection with the coronavirus SARS-CoV-2
Another finding of the study is that there are several antibodies present in MIS-C patients that attack the body's own proteins,