B-cell function in Kawasaki disease and the effect of high-dose gamma-globulin therapy.

We studied in vitro B-cell function in Kawasaki disease (KD). By plaque-forming assay, IgG-, IgA- and IgM-secreting cells in the first week of KD were markedly increased, and recovered to a normal level in the second week in many cases. Lymphocyte blast formation with Staphylococcus aureus Cowan I (SAC), a B-cell-specific mitogen, was suppressed in the acute phase, and recovered to a normal level in the convalescent phase. By flow cytometry, HLA-DR- and HLA-DQ-positive cells were increased in the acute phase of KD. CD3- and CD4-positive cells were also decreased. CD8-positive cells showed no significant change. In five patients, CD4-positive cells with HLA-DR positivity neither increased in the acute phase nor changed during the course of illness. From our results, it can be considered that pathogenic microorganisms or toxins activate B cells directly in KD without the association of T cells. We also studied the effect of high-dose gamma-globulin therapy on B-cell function in KD. However, the results indicated that this form of therapy had no significant effect on B-cell functions.