ANTIBODIES TO ENDOTHELIAL-CELLS IN KAWASAKI-DISEASE LYSE ENDOTHELIAL-CELLS WITHOUT CYTOKINE PRETREATMENT

Kawasaki disease (KD) is characterized by diffuse vasculitis and marke d immune activation. To confirm the presence of antiendothelial cell a ntibodies (AECA) and cytotoxicity of AECA, we investigated the presenc e of AECA using ELISA and cytotoxicity of AECA in KD. Sera from patien ts with acute KD were assessed for binding to human umbilical vein end othelial cells (HUVEC) using a cell-based ELISA, and for cytotoxicity against HUVEC as indicated by the conversion of a tetrazolium salt (MT T) into a coloured product. IgM AECA were detected in 8/19 KD sera, Ig G AECA were detected in 5/19 KD sera, Significant differences in both AECA titres existed between patients and febrile and afebrile controls . Six out of 19 patients showed complement-dependent cytotoxicity agai nst HUVEC. Cytotoxicity was significantly enhanced by pretreating HUVE C with tumour necrosis factor (TNF), and reduced by incubation with ga mmaglobulin. Serum titres of IgM AECA in the KD patients were positive ly correlated with cytotoxicity. Findings suggest that IgM AECA mediat es complement-dependent cytotoxicity against endothelial cells in pati ents with KD, and gammaglobulin may reduce complement-dependent cytoto xicity of AECA against endothelial cells.