How Antibody Treatment for MIS-C Works
The depletion of neutrophils could be how intravenous immune globulin (IVIG) is able to treat multisystem inflammatory syndrome in children (MIS-C).
MIS-C is a rare condition that usually affects school-age children who initially had only mild COVID symptoms or no symptoms at all. The researchers also found that IVIG works in a similar manner for treating Kawasaki disease, another rare inflammatory condition that affects children and shares symptoms with MIS-C.
MIS-C is marked by severe inflammation of two or more parts of the body, including the heart, lungs, kidneys, brain, skin, eyes and gastrointestinal organs. Its symptoms overlap with Kawasaki disease, and treatments for MIS-C are partly guided by what is known about the treatment of Kawasaki disease. IVIG, which is made up of antibodies purified from blood products, is a common and effective treatment for heart complications caused by Kawasaki disease. For MIS-C patients, however, IVIG alone does not always resolve symptoms, and healthcare providers may need to prescribe additional anti-inflammatory drugs.
In order to better understand how IVIG works and to improve treatments for children with MIS-C, researchers profiled immune cells from patients with MIS-C or Kawasaki disease. The team sampled cells before treatment began as well as 2 to 6 weeks after patients received IVIG, and found that neutrophils from these patients were highly activated and a major source of interleukin 1 beta (IL-1β), a driver of inflammation. After IVIG treatment, these activated neutrophils were significantly depleted in patients with MIS-C or Kawasaki disease.
The study authors believe their findings are the first to explain why IVIG is effective for both conditions. More work is needed however to understand how IVIG causes cell death in these activated neutrophils and why certain patients with MIS-C require additional anti-inflammatory treatments.
The findings appear in the Journal of Clinical Investigation.
Source: National Institutes of Health
