Abnormalities of immunoregulation in Kawasaki syndrome.

The object of our investigation was to determine the immunoregulatory abnormalities in 48 children with Kawasaki syndrome. We demonstrated a global lymphocytosis with marked expansion of the B cell subset. Despite an increase in B cell numbers, there was a decrease in in vitro immunoglobulin production in response to pokeweed mitogen and hydrocortisone stimulation. These abnormalities correlated with a marked increase in the percentage of CD4+2H4+ (CD4+CD45R+) T cells, a T cell subset thought to be responsible for inducing suppression. Other abnormalities of T cells include cutaneous and in vitro anergy and evidence of T cell activation. Our results suggest that the B cell abnormalities seen in Kawasaki syndrome may be partially explained by defects in T cell immunoregulation.