EXPERIMENTAL GRANULOMATOUS VASCULITIS INDUCED BY SENSITIZATION WITH ASCARIS-SUUM ANTIGEN IN MICE

Experimental sensitization by repeated intramuscular injection of Asca ris suum antigen (Ag-As) supplemented with Freund's incomplete and com plete adjuvants was carried out in 50 BALB/c CrSI c male mice (sensiti zed group) for 24 weeks, and the results were compared with those in a control group of 25 mice. At the injection sites of the sensitized gr oup, granulomatous angiitis with eosinophil infiltration was observed in all mice, and fibrinoid angiitis in only four, By light and electro n microscopic examinations pulmonary granulomatous vasculitis with a f ew eosinophils was observed at a high frequency (80%) after 12 experim ental weeks. Immunohistochemical examination revealed pulmonary vascul ar and perivascular infiltration of L3/T4 (CD4) positive cells, B cell s, IgG and C3 positive cells in addition to activated macrophages, Thy -1 T cells, IgE positive cells, and IgM positive cells after 12 experi mental weeks, There were significant increases in the eosinophil cell count of the peripheral blood, the hemagglutination titers of the shee p erythrocytes, IgE and IgM antibodies to AS-As by ELISA and Western b lotting after 8 experimental weeks, After 12 experimental weeks the Ig G antibody to the Ag-As was low, but it increased significantly, and t he sera showed multiple precipitation lines to the AS-As by the Ouchte rlony method. In conclusion, the pulmonary granulomatous vasculitis in this study is considered to consist of allergic reactions of type IV and probably type III based on type I.