According to new research from the Journal of Infectious Diseases, a new protein epitope has been discovered while testing the immune response of people with Kawasaki Disease.
Kawasaki Disease, also referred to as Kawasaki Syndrome, is an acute illness that normally presents in children under the age of 5. However, it may present in older children or even adults on very rare occasions. It occurs when blood vessels become inflamed. According to the CDC, it is the leading cause of acquired heart disease in the United States. Thus, any children displaying symptoms should be treated by their doctors as soon as possible.
The Research
Because of the epidemiological features of Kawasaki disease, researchers hypothesized that Kawasaki disease was caused from some sort of viral infection. They even considered that a novel hepacivirus may be the cause. A novel hepacivirus is one that is new or previously undiscovered.
To begin their research, researchers isolated peripheral blood plasmablasts from 11 children with Kawasaki disease within one to three weeks of their fever. Plasmablasts are young plasma cells that have antibodies and may mature into a fully formed plasma cell. From these plasmablasts, researchers created monoclonal antibodies. According to the American Cancer Society, monoclonal antibodies (mAbs) are man-made (created in a lab). They find and target disease-causing antigens in the body. Learn more about mAbs here.
Researchers compared these monoclonal antibodies with lung tissue taken from a Kawasaki patient. They identified 10 monoclonal antibodies with strong positive staining.
Viral Epitopes
During their screening, researchers found nonstructural protein 4A. Using bioinformatic analysis, they then discovered a shared link between the top peptides and later reduced this to an 8 amino acid epitope. This novel epitope matches no former hepaciviruses.
Next, a peptide with this epitope was isolated and tested against 60 monoclonal antibodies, five of which reacted to the peptide. When testing eight Kawasaki patients and 17 infants (who acted as a control group), 62.5% of the patients had blood serum containing the peptide.
Why is this Important?
Perhaps most excitingly, the protein epitope discovered during this research is the first of its kind. As quoted by Morgan E. Meissner, the researchers stated that:
“This is the first discovery of a specific antigen recognized by the immune response to [Kawasaki disease].”
Future research may be able to find additional antigens. At the very least, this could have far-reaching implications for the future of Kawasaki disease research.
Current Treatments for Kawasaki Disease
According to the Cincinnati Children’s Hospital, treatment for Kawasaki disease includes:
- A two to five day hospitalization
- Intravenous immunoglobulin (IVIG)
- High-dose aspirin until inflammation and fever are done
- Low-dose aspirin for six to eight weeks following hospital discharge
- Frequent visits to a cardiologist
IVIG is a blood infusion made from plasma that helps fight off infection. It is most effective within the first 10 days of someone having Kawasaki disease, and can reduce the risk of additional heart-related issues by over 75%.
Adjusting Treatments Based on Up-and-Coming Research
Currently, researchers are unclear regarding the cause of Kawasaki disease or how children develop this condition. By recognizing which disease-specific antigens are present in children with Kawasaki disease, researchers, clinicians, and epidemiologists will be better able to craft effective and appropriate treatments.
While a 75%+ reduction rate for heart issues from IVIG is incredibly promising, the discovery of new antigens could provide researchers with the ability to reduce the risk even farther. Additionally, this could give researchers more insight into why specific groups of children develop Kawasaki disease as well as why it might present in older individuals.
