Antigenic recognition by intravenous gamma-globulin of selected bacteria isolated from throats of patients with Kawasaki syndrome.

Kawasaki syndrome (KS) or mucocutaneous lymph node syndrome is an acute febrile exanthematous illness of unknown etiology. Therapy with intravenous gamma-globulin (IVGG) results in rapid defervescence, disappearance of signs and symptoms of inflammation and prevention of coronary artery aneurysms. We hypothesized that IVGG might neutralize a bacterial toxin produced by a staphylococcus or streptococcus present in the nasopharynx. We further speculated that this toxin might be detectable in serum or urine of patients. The goal of this work was to identify microbial antigens in different materials taken from patients with a clinical diagnosis of KS. We tested 23 aerobic bacterial isolates from throat cultures from 15 patients with KS, acute serum from 121 patients and 38 acute urine specimens from patients with KS. The patients ranged in age from 1 to 6 years. Specimens were tested in a standard system of counterimmunoelectrophoresis and reacted against IVGG prepared in a 25% solution. Ten of 23 aerobic bacteria (43.5%) isolated from throat cultures demonstrated a precipitation reaction with IVGG. Counterimmunoelectrophoresis testing of IVGG against acute serum and acute urine specimens was uniformly negative. IVGG contains precipitating antibody against a limited number of aerobic throat organisms. It is possible that antigenic products of one of these bacteria may be involved in the pathogenesis of KS.