Correlation between elevated platelet count and immunoglobulin levels in the early convalescent stage of Kawasaki disease

Kawasaki disease (KD) may be an acute systemic immune-mediated disease which occurs after infection of unknown KD pathogen(s). The aim of this study is to evaluate the changes in platelet count and immunoglobulin (Ig) levels (IgG, IgM, IgA, and IgE) during hospitalization. Forty-three patients with complete KD who received intravenous Ig at 2 g/kg were enrolled in South Korea. The platelet count and Ig levels of the patients were examined twice at presentation and around discharge (mean 6.2 ± 2.4 days apart) and the relationships between platelet level and Ig levels were evaluated. The mean patient age was 31 ± 18 months; 28 patients were male and 15 were female. The values of all parameters measured, with the exception of IgE, were significantly increased at the second examination compared with their values at presentation. These values gradually increased over time after fever onset, over periods ranging from 2 to 16 days. The extent by which platelet levels increased over these 2 time points was correlated with the extents by which IgG (P < .01), IgM (P < .01), and IgA levels (P = .01) increased. Both the platelet count and the Ig (IgG, IgM, and IgA) levels increased with a correlation each other during the early convalescent stage of KD. This finding suggests that all Ig subtypes except IgE and platelets may be involved in the recovery from KD and that the extent of increased parameters may reflect the degree of systemic inflammation in acute KD.