Early intravenous gamma-globulin treatment for Kawasaki disease: the nationwide surveys in Japan.

Objective: To determine the optimal period of intravenous gamma-globulin (IVGG) treatment, using the database from nationwide Kawasaki disease surveys in Japan.
Study Design: We selected patients who first visited a doctor within 3 days of illness and received IVGG treatment within 9 days of illness. We divided these patients into 2 groups: an early group (treated on days 1-4: 4731 cases) and a conventional group (days 5-9: 4020 cases). We compared the rate of additional IVGG and prevalence of cardiac sequelae between these groups.
Results: The rate of additional IVGG in the early group was significantly higher than those of the conventional group (OR, 1.12 [95% CI, 1.10-1.16]). There were no significant differences in cardiac sequelae between the two groups.
Conclusions: There is no evidence that IVGG treatment on day 4 or earlier has greater efficacy in preventing cardiac sequelae than treatment on days 5 to 9. In addition, early treatment is likely to result in a greater requirement for additional IVGG. However, there is also no evidence that early treatment increases the prevalence of cardiac sequelae in a clinical practice setting, where additional IVGG can be given to those whose initial treatment fails.