Kawasaki Disease: Solving a Diagnosis Dilemma with Proteins

BY MARK SHWARTZ

WINTER 2003 - When children get a fever, their body temperature usually returns to normal within three days. But in a mysterious syndrome called Kawasaki Disease, one of the main symptoms is a fever that lasts five consecutive days or more. If left untreated, the child can suffer a coronary aneurysm -- the sometimes-fatal swelling of the blood vessels that feed the muscles of the heart.

Researchers will use the Biomek and Ciphergen workstations to study blood samples from Kawasaki Disease patients. The highly calibrated machines automatically will prepare hundreds of samples and will use laser-activated mass spectroscopy to detect the abnormal presence of thousands of different proteins.

"In my 25 years as a pediatrician, I've seen over 100 cases of Kawasaki Disease," says Theodore C. Sectish, M.D., director of the pediatric resident program at Stanford. "The disease is puzzling because we still don't know what causes it."

First identified in the late 1960s by Japanese researcher Tomisaku Kawasaki, the disease is characterized by high fever, bloodshot eyes, body rash, cracked lips, swollen lymph nodes in the neck, and swelling and peeling of the hands and feet. Within 10 days, coronary aneurysms will form in 20 percent of patients, so it's crucial to treat them as soon as possible with the only effective therapy known: intravenous immunoglobulin (IVIG) -- an infusion of antibodies given to the patient to fight off bacteria and other infections.

Unfortunately, there is no diagnostic test for Kawasaki Disease, so physicians have to make a judgment on whether to start IVIG therapy based on symptoms that also appear in other illnesses.

"Our difficulty as clinicians is that we may be treating many kids with IVIG who don't have Kawasaki Disease because we do not have a confirmatory test," Sectish explains. "IVIG is not without risk or cost, since IVIG can trigger transfusion reactions or anaphylaxis, and it's a costly treatment -- $6,000 for a single dose."

To prevent coronary aneurysms, Kawasaki patients also are given aspirin for six to eight weeks, but children who take aspirin are susceptible to Reye's Syndrome -- a serious disorder that can lead to liver problems and coma.

"Right now, we can rule out some diseases, but we don't have a test to rule in Kawasaki Disease," Sectish says. "What we want to be able to say is, ‘we think the patient has Kawasaki, and now we have a test that confirms our diagnosis.'"

In an effort to develop a Kawasaki test, Sectish has formed a remarkable research team that includes Joshua Schiffman, M.D., Packard Hospital's pediatric chief resident, and two medical students -- Natalie Pageler and Rebecca Weintraub.

Using a grant from the Pediatric Research Fund, the researchers recently launched a proteomic study that will look for unusual patterns in the way proteins in a patient's cell are distributed. The grant was made possible through community gifts to the Lucile Packard Children's Fund, which, in part, are used to support innovative research efforts at the Hospital. The study is being conducted in collaboration with Harvey Cohen, M.D., Ph.D., Packard's chief of staff, and John Whitin, Ph.D., a senior scientist and biochemist who leads Cohen's lab.

The idea behind the study is that certain diseases produce abnormal concentrations of certain proteins. But a human cell produces thousands of different proteins, so finding unusual patterns of distribution is a time-consuming endeavor that can only be done using state-of-the-art biotechnology.

In their study, Sectish and his colleagues will compare protein distribution in two groups of patients: children diagnosed with Kawasaki, and children who have had a 100º F fever for at least three days but have been diagnosed with another disease. Blood samples will be taken from both groups and placed in a protein chip array -- a newly designed $350,000 robotic instrument that uses laser technology and mass spectroscopy to identify thousands of proteins at a time.

"One leading thought is that Kawasaki Disease is triggered by a viral infection, and that certain proteins in the body are elevated in reaction to the virus," Sectish says. "If that turns out to be the case, then maybe we can have a better understanding of what's actually causing the disease." The next logical step would be to develop some type of therapy to prevent it, he adds.

Schiffman notes that "one thing that makes this disease such a diagnostic dilemma is that younger children, especially those less than six months of age, have what is called atypical Kawasaki Disease. These children don't get all of the symptoms, so you don't really know if it's Kawasaki or not."

"The end goal of proteomics is to produce clinical applications," says Weintraub, a fourth-year medical student. "What's fascinating about Stanford is that we're able to promote technology and find its clinical applications quicker because of the diverse nature of the faculty. This is really the beginning of a whole new era."