Medical researchers at the Mount Sinai Health System in New York discovered a rare yet severe inflammatory syndrome in children, who had previously been diagnosed with COVID-19, in April of this year.

According to the CDC, multisystem inflammatory syndrome in children is an immune condition that impacts different parts of the body including the hearts, lungs, kidneys, brain, skin, eyes or even gastrointestinal organs.

Some of the symptoms of this rare syndrome include abdominal pain, bloodshot eyes, chest tightness or pain, low blood pressure, neck pain, a rash, feeling fatigued or even severe inflammation of the organs impacted by the syndrome.

Similarly to COVID-19, these symptoms present themselves differently in children, meaning that not every child will have all of the same symptoms.

It was discovered that this syndrome does not just impact children. Since June of last year, several reports of the syndrome have been made by adults.This syndrome is known as MIS-A and only impacts adults.

“In terms of symptomatology, it’s pretty similar for adults and children,” stated Michael Loncharich, MD, of Walter Reed National Military Medical Center in Bethesda, Maryland.

The CDC warns that MIS can appear more complicated in adults than in children.

Despite the differences in the complications of this syndrome, both MIS-A (Multisystem inflammatory syndrome in adults) and MIS-C (Multisystem Inflammatory Syndrome in Children) can develop in those diagnosed with COVID-19 days to weeks after being diagnosed with COVID-19.

In a study published in Nature Communications, researchers discovered that there was a lower prevalence of a particular type of cell in the immune system than in those who were not diagnosed with multisystem inflammatory syndrome after a COVID-19 diagnosis.

According to the Louisiana Department of Health, the number of MIS-C deaths in Louisiana alone makes up about 20% of all cases of MIS-C in the United States.

However, this syndrome is not exclusive to the United States.

In Malda, 22 children between the ages of two and eight years were diagnosed with multisystem inflammatory syndrome.

In fact, the principal of the Malda Medical College and Hospital, Parthapratim Mukherjee, spoke on the subject when interviewed by The Telegraph.

“We suspect these children contracted COVID-19 during the second wave and didn’t manifest any symptoms,” Mukherjee said. “That is why they might have got MIS-C. As they are not infected with COVID-19 now and MIS-C is not, they have been admitted to the pediatric ward and not in the special COVID-19 ward.”

After these diagnoses became more prevalent, doctors recommended that any child with flu-like symptoms for 72 hours should be taken to a doctor.

Because of the increase in cases of this rare inflammatory syndrome, scientists believed that it was of extreme importance that they start to determine why the children are being diagnosed with this syndrome and how they would be able to treat it.

“As this was and remains a major disease related to the ongoing pandemic, we thought it would be essential to investigate its etiology,” said Dr. Noam D. Beckmann, a correspondent of the study. “Follow-up studies could identify drug targets that could prevent COVID-19 from progressing into MIS-C.”

According to the study, there were lower levels of natural killer cells, a type of cell that is meant to kill tumor cells and cells infected with a particular type of virus such as COVID-19, in the individual’s immune system.

A volunteer team of more than 100 nurses, doctors and researchers was created to determine the best ways of treating this syndrome.

This team started to evaluate this syndrome by collecting blood samples from hundreds of COVID-19 patients, who were admitted to Mount Sinai hospitals.

Scientists discovered that “exhausted cytotoxic T cells” may be key to treating MIS-C.

According to a Mount Sinai study, CD8+ cells, or cells that are responsible for immune defense against intracellular pathogens, are persistently exposed to pathogens. Because of this, the cells enter an “exhaustion” state, meaning that they are less effective and are unable to proliferate.

However, based on the research done in this study, the team has discovered that the regulator, TBX21, which is responsible for regulating the network associated with natural killer cells and exhausted CD8+ T cell functionality, could also possibly be a way of treating MIS-C. According to Medical News Today, TBX21 is a promising therapeutic target because, “it serves as a master coordinator of the transition of CD8+ T cells from effective to exhausted.”

Since COVID-19 first appeared, scientists concerned themselves with the possibility of different illnesses that might appear in the days that someone has COVID-19 and the days after.

If you or someone you know start to display the symptoms for MIS-C or MIS-A during or after a COVID-19 diagnosis, a doctor visit might help to determine if one of these two syndromes has presented itself.