Kawasaki disease: monitoring of circulating immune complexes.

We followed the levels of circulating immune complexes (CIC) in 27 patients with Kawasaki disease (KD) from the acute stage of the disease through convalescence, using the test for platelet-reactive IgG-IC, and C1q-binding and conglutinin-binding enzyme immunoassays. CIC were detected by one or more techniques in all but one patient. Positive results were obtained most often with the test for platelet-reactive IgG-IC. Measurement of complement components C3 and C4 in 14 patients revealed an increase in C3 levels during the first few weeks of the disease and normal levels of C4. The blood platelet count correlated directly with the level of platelet-reactive IgG-IC. The highest levels of CIC were found during weeks 3 through 7 after the onset of disease. Measurement of CIC is, however, not applicable to the clinical follow-up of patients with KD.