An unusual childhood heart disease that primarily affects Asian children and reaches epidemic proportions in three-year cycles may be treatable with a blood serum protein.
Doctors suspect a virus as the cause of Kawasaki syndrome, a disease that can cause heart attacks in babies and usually occurs in children under 5.
Dr. Masato Takahashi of Childrens Hospital in Los Angeles is heading a team of researchers at six medical centers across the country who are testing the effectiveness of gamma globulin therapy on the disorder.
"Over the past year and a half we have been collecting data on the gamma globulin therapy," Takahashi said. "But before we accept that form of treatment, we want to establish its safety."
Immune System Antibodies
Gamma globulins are immune system antibodies found in the blood. In special preparations, they have been used effectively to fight many other viral diseases.
Kawasaki syndrome, characterized by a high fever, heart inflammation and swollen tongue, was first described 19 years ago in Japan, where doctors recently have been using gamma globulin therapy as the preferred treatment.
The syndrome is of particular concern to pediatric heart specialists because 20% of the children who contract the disease develop an aneurysm, or bulge, in the coronary artery. Aneurysms, if they break, can be fatal.
Gamma globulins do not prevent aneurysm development but can eliminate some of the preliminary symptoms--coughing, sore throat and general malaise--and prevent the acute phase of the disease.
It is during the acute period of the disease, when children develop fevers as high as 105 degrees, that heart inflammation and heart attack can occur, Takahashi said.
One difficulty, however, is that the disease is usually diagnosed in the acute phase, Takahashi said. The preliminary symptoms can be mistaken for something else.
Because there is no way of keeping official track of Kawasaki syndrome in the United States, Takahashi said, the disease is "grossly under-reported in this country and often goes unrecognized."
Researchers in Japan say that during a non-epidemic year, an estimated 6,500 cases of the syndrome are reported. But during an epidemic cycle the number of cases soars to 15,000.
"We had an outbreak in the U.S. and Japan in 1980-83, and now again in '86 we're seeing the number of cases increasing," Takahashi said.
The researcher said efforts are centering on a search for a virus as the prime culprit in the disease because cases tend to appear in seasonal clusters during an epidemic, peaking in winter and spring much like the respiratory viruses that cause influenza.
Oriental Children Susceptible
"We've seen cases appear in all races of children in the U.S., but even here it appears that Oriental children are more susceptible and therefore probably have a predisposition to the virus," Takahashi explained.
He said it is not unusual for certain races to be susceptible to viruses that are not highly prevalent among the rest of the world's populations.
Takahashi cited the Epstein-Barr virus, responsible for mononucleosis, as the cause of a severe heart disease found in African children but not often seen in other children.
Boston Children's Hospital, Chicago Memorial Hospital, the University of Colorado, Kapiolani Hospital, Honolulu and the University of California at San Diego also are participating in the Kawasaki disease study.