The effect of intravenous immunoglobulin on lymphocyte populations in children with Kawasaki syndrome.

High dose intravenous immunoglobulin (IVIG) is extremely effective therapy for Kawasaki syndrome (KS), but the mechanism of action remains unknown. The present study was performed to determine the effect of IVIG on lymphocyte populations and lymphocyte activation markers in 15 children with KS. Following IVIG, there was a decrease in the percentage of CD19 cells and an increase in the percentage of CD8 cells, but there was no change in the proportion of CD3 or CD4 cells. Moreover, there was no change in the percentage of activated CD4 or CD8 cells, as measured by HLA DR and interleukin-2 receptor expression after IVIG therapy. These results indicate that IVIG is effective treatment for KS via mechanisms other than the direct modulation of T cell activation markers.