COVID-19 in children: MIS-C is different from Kawasaki disease, may be after-effect of SARS-CoV-2 infection

Children were initially said to be safe from COVID-19 as not many cases were reported in the pediatric population. Later a lot of children showed up with a sort of hyper inflammation that presented with symptoms similar to Kawasaki disease — a condition that leads to inflammation of blood vessels in the body and usually affects kids younger than five years of age. However, soon, the condition was labelled Multisystem inflammatory syndrome  in children (MIS-C) and was hypothesised as a COVID-19 related syndrome in children because of the presence of anti-coronavirus antibodies in most patients. Now, a recent study published in the Journal of Clinical Investigation, suggests that MIS-C may actually be a post-COVID condition and is different from both Kawasaki disease and severe COVID-19. Cytokines, viral cycle threshold and burr cells To study the difference between COVID-19, MIS-C and Kawasaki disease, the researcher at the Children’s Hospital of Philadelphia studied 20 patients of COVID-19. These included nine with severe COVID-19, five with mild COVID-19 and six with MIS-C. Here are some differences that were found between MIS-C and COVID-19:

• MIS-C patients had higher viral cycle threshold than those with severe COVID-19. Viral threshold refers to the number of PCR cycles (heating and cooling steps in PCR) needed to identify the presence of the virus in a sample. This indicated that MIS-C patients did not have an active infection and they may have developed the condition after recovering from COVID-19.
• MIS-C patients also had a different cytokine profile. Cytokines are proteins involved in inflammation and excess inflammation is one of the life-threatening complications associated with COVID-19. The study indicated that those with MIS-C had high levels of IL-10 and TNF-alpha, which were found in lower amounts in those with COVID-19 (both mild and severe).
• Most patients with MIS-C had burr cells in their peripheral blood samples, which are a type of red blood cell (RBC) with evenly spaced spikes on their surface when seen under the microscope. On the other hand, only 40% of those with severe COVID-19 had burr cells in their peripheral blood samples and the cells were not present in any patient with mild disease.

MIS-C and Kawasaki disease (KD) Two major differences between MIS-C and KD led the scientists to believe that the two are different conditions. First of all, it is known that those with Kawasaki disease do not have high levels of IL-10 as is found in those with MIS-C. However, KD patients have higher levels of other cytokines. And secondly, there is the difference between symptoms of the diseases. For example, symptoms like rashes, diarrhoea and abdominal pain overlap between the two, but those with MIS-C present with severe inflammation in the abdomen and Kawasaki patients don’t. The authors of the study pointed out in a news release that most pediatric patients have mild disease but in some, the virus seems to trigger MIS-C. However, it remains to be known what is the reason for this trigger and why it happens in only some children. For more information, read our article on Multisystem inflammatory syndrome in children. Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health.