A new study may shed light on why some youngsters develop the rare and dangerous multisystem inflammatory syndrome in children (MIS-C) after recovering from COVID-19 while most do not. The syndrome can cause severe inflammation of blood vessels, the heart, lungs, kidneys, and other organs. The immune system is more highly activated in children with MIS-C than in those with COVID-19, study co-author Dr. John Wherry of University of Pennsylvania Perelman School of Medicine told Reuters. However, in MIS-C patients, the activated immune system quickly settles down, and symptoms improve, often faster than during a bout with COVID-19. "One interesting finding," Wherry said, "was that MIS-C patients, who usually come to the hospital because of cardiovascular problems, have an unusual population of highly activated, vascular patrolling T cells. Patients who have high numbers of these cells were more often treated with medication for vascular problems suggesting these immune cells are somehow related to the pediatric vascular problems in MIS-C." He continued, "This discovery from pediatric patients also allowed discovery of a similar immune signature in adults. These findings suggest a possible connection between a specific type of activated immune cell and some of the vascular complications of COVID-19 disease in children, and perhaps adults." "The identification of an immune cell type connected to vascular symptoms may identify a new (treatment) target if approaches can be developed to target such cells," he said. The study was posted on medRxiv ahead of peer review. Source
