Researchers have identified possible triggers for multisystem inflammatory syndrome in children (MIS-C) and acute respiratory distress syndrome (ARDS) related to COVID-19, according to a small Australian study.
The peer-reviewed study, published on Monday in the journal Nature Communications, documents the mechanisms that appear to be activated in children severely ill with COVID-19. Researchers suggest that blood clotting and how proteins react to the virus were key triggers for serious infections. Researchers hope it could eventually help with earlier diagnosis and specialized treatments.
“Our research was the first to uncover the specific blood clotting and immune protein pathways impacted in children with COVID-19 who developed serious symptoms,” co-author Conor McCafferty, a Murdoch Children’s Research Institute (MCRI) researcher and University of Melbourne PhD student, said in a statement.
MIS-C is an inflammatory reaction in the body that can affect multiple organs, including the heart, lungs, kidneys, and brain. Symptoms include fever, abdominal pain, vomiting, dizziness or lightheadedness, bloodshot eyes, and skin rash. While rare, it can occur in school-aged children in the weeks following a COVID-19 infection, and have similarities to Kawasaki disease and toxic shock syndrome, making a quick diagnosis challenging. MIS-C can be very serious, but is treatable.
Meanwhile, ARDS is a serious form of lung damage caused by a buildup of fluid in the lungs, cutting the amount of blood oxygen in the body to dangerous levels. While less than two per cent of children with COVID-19 were admitted to intensive care (in the study, or in Australia?), COVID-19 ARDS is one of major causes in these serious cases, the paper noted.
For this study, 54 blood samples were collected. Twenty from healthy children, five from COVID-19 ARDS patients, and 29 from MIS-C patients. Because the healthy control samples were taken from before the pandemic, researchers were certain those samples had no COVID-19 exposure. None of the MIS-C patients had pre-existing conditions, while one COVID-19 ARDS patient had sickle-cell anaemia and another had leukemia.
“A significant limitation in interpreting the results in our COVID-19 ARDS population is the low sample size in comparison to the other groups, which reflects the rarity of COVID-19 ARDS in children in Australia,” researchers noted in the study.
Scientists used a discovery proteomics technique, which is used to gather information about all the proteins within a sample. The technique means hundreds of proteins circulating in the blood are analyzed. Eighty-five proteins were found that were specific to MIS-C and 52 to COVID-19 ARDS.
The findings are consistent with earlier research, researchers noted in the study, but those used techniques that investigated specific proteins, as opposed to analyzing hundreds of proteins together.
“Our study provides the basis for future studies with access to larger sample numbers to expand on our research,” the authors wrote in the study.
“Our study also only uses a discovery proteomics technique and, while we have established a foundation for further research, targeted protein analysis will be required before this work could be implemented clinically.”
The results help scientists better understand the processes that underlie severe COVID-19 in children, researchers said.
“Knowing the mechanisms associated with severe COVID-19 in children and how the blood clotting and immune systems in children react to the virus will help diagnose and detect acute COVID-19 cases and allow us to develop targeted treatment,” Vera Ignjatovic, a professor at MCRI, said in a statement.