High antiviral antibody levels may herald childhood COVID-19 complications

Blood levels of antibodies to SARS-CoV-2 can be used to distinguish children with multisystem inflammatory syndrome (MIS-C), a potentially serious but rare complication of viral infection, Emory University said. Researchers in children’s health care at the School of Medicine and Atlanta said:

Children with MIS-C had significantly higher levels of antiviral antibodies, more than 10-fold Children A mild symptom of COVID-19, discovered by the research team.

Results published in the journal Pediatrics, May help doctors establish a diagnosis of MIS-C and understand which children are likely to need additional anti-inflammatory treatment. Children with MIS-C often develop heart problems and low blood pressure and require intensive care.

High antibody levels may represent exaggerated immune responses or delayed complications of COVID-19, or a combination of both, according to Christina Rostad, a pediatric associate professor at Emory University School of Medicine, infectious diseases. .. disease Child specialist. Senior author Dr. Preeti Jaggi is an Associate Professor of Pediatrics (Infectious Diseases) at Emory University School of Medicine and Pediatrics.

“One of the challenges in interpreting these findings in MIS-C children is not knowing when they actually got the virus,” Jaggi says. “With the rapid emergence of MIS-C, both Children’s doctors and Emory researchers need to work together to quickly understand the clinical course, treatment, and pathophysiology of the disease, helping clinicians and basic scientists A lot of team effort was needed.”

Since the writing of this manuscript, child doctors have continued to look at cases of COVID-19. In addition, more than 50 cases of MIS-C meet the definition of MIS-C, which requires hospitalization in a child’s healthcare system.

“These cases underscore the importance of all our efforts as a community to reduce the transmission of this virus. Wearing masks, washing hands and avoiding large gatherings. That could save someone’s life,” says Rostad.

According to Centers for Disease Control and Prevention, patients with MIS-C usually have persistent fever, abdominal pain, vomiting, diarrhea, and rash, and in severe cases, lower blood pressure and shock.

How MIS-C evolves remains a mystery. Recent reports suggest that it reaches a second wave of inflammation after the first viral infection. MIS-C children, studied by Emory and Children researchers, did not recall having previously had fever or respiratory disease, even if they had high levels of antiviral antibodies. However, the majority were negative for active infection (by RT-PCR) at the time of admission.

The authors state that it seems “paradoxical” that children without previous symptoms of SARS-CoV-2 infection develop such a strong immune response. Some children with active infections are asymptomatic, but may suggest their ability to develop robust and aberrant immune responses associated with MIS-C.

“These studies provide evidence that MIS-C is abnormal Immune reaction “It’s about fighting SARS-CoV-2 infections in children. But the mechanism of the disease process and why some children get symptoms and others don’t, remain vigorous. Is being researched.”

Children with MIS-C exhibited mainly gastrointestinal and respiratory symptoms when they first came to the hospital. Some of them developed myocardial dysfunction with reduced ejection fraction, a measure of the heart’s ability to pump blood. All patients with MIS-C were required to be admitted to the intensive care unit because of low blood pressure.

Between March and May 2020, researchers investigated 10 children hospitalized with MIS-C, 10 with symptomatic COVID-19, 5 with Kawasaki disease, and 4 hospitalized controls. did. Kawasaki disease is a childhood inflammatory disease that affects blood vessels, including the coronary arteries, which share some functions with MIS-C. The average age of MIS-C children was 8.5.

The time elapsed between the onset of symptoms and the time the antibody sample was taken generally varied between 0 and 20 days, with a small number of people after 20 days in the MIS-C group. The researchers used a test developed by the co-author Dr. Jens Lamart to test antibodies to the receptor binding domains of the viral spike and viral nucleocapsid proteins. They also performed a live virus neutralization assay in the lab of co-author Dr. Mehul Suthar.

All children with MIS-C were treated with intravenous immunoglobulin (a mixture of provided antibodies) and half received corticosteroids, a common anti-inflammatory drug. Some members of the COVID-19 group were treated with antiviral or immunomodulatory drugs such as lemdesibir (4 children) and convalescent plasma (2). All the MIS-C children eventually went home. Two of the patients with symptomatic COVID-19 were being treated for leukemia and died of the underlying disease process.