New KD Study Examines Plasmablasts in KD Patients

New study identifies a previously unrecognized virus from a known virus family that has caused an infection in KD children during the onset of symptoms

The results of a new study conducted by Dr. Anne Rowley and her team at Pediatrics, Northwestern University Feinberg School of Medicine, Ann & Robert H. Lurie Children’s Hospital of Chicago and Loyola University Chicago Stritch School of Medicine were presented during the Pediatric Academic Societies Conference which took place on April 24 – May 1 in Baltimore.

The study examined “plasmablasts that were clonally expanded in the peripheral blood of 11 children with Kawasaki disease (KD) and made monoclonal antibodies from these plasmablasts,” said Anne Rowley, MD. Plasmablasts are the cells in our blood that will mature into antibody producing cells. We make antibodies to fight off infections. Normally, when we are well, we have small numbers of plasmablasts in our blood that are not specific for any one kind of infection. However, recent studies have shown that at 1-2 weeks after a specific infection, ~75% of the plasmablasts in the blood are those that have been expanded by the immune system to produce antibodies to fight off that specific infection. After that time, plasmablasts go back to being very diverse cells that are not specific for one kind of infection.

The study isolated plasmablasts from KD children 1-2 weeks after fever onset and made the antibodies from the cells. The results showed that the KD antibodies bind to proteins related to those of a specific virus family. The conclusion from these studies is that a previously unrecognized virus, related to a known virus family, has caused an infection in KD children around the time of onset of fever and other KD symptoms. These results fit well with prior studies showing “virus footprints” in tissues from KD children, nearby virus-like particles in the tissues, and an antiviral immune response in coronary arteries from KD children.

“We have a lot of work ahead. We need to discover the entire gene sequence of the virus and develop assays for infection. This will allow us to perform more studies to determine if this virus is the single cause of KD or just a predominant cause. Our long-term goals are to develop a diagnostic test, improved therapy, and prevention of KD,” said Dr. Rowley.

To learn more about Dr. Rowley’s work or to make a contribution to her research projects please visit Rowley Laboratory at Ann & Robert H. Lurie Children’s Hospital of Chicago.