IgE anti-brucella antibodies in the course of human brucellosis and after specific vaccination.

Using two different techniques (an original RAST-like radio-immunoassay and indirect immunofluorescence) serum IgE anti-Brucella antibodies were detected in 59% brucellosis patients (76% in early samples from acute brucellosis) and in 43% subjects vaccinated with a phenol-insoluble Brucella fraction. IgE anti-Brucella antibodies are shown to appear after IgM but before IgG anti-Brucella antibodies in the course of the anti-Brucella response. There is no correlation between the presence of IgE anti-Brucella antibodies and the severity of brucellosis or its clinical manifestations. On the other hand, a significant association has been evidenced between the presence of mild reactions to primary vaccination and that of IgE antibodies induced by this vaccination. These findings are discussed in terms of their possible functional significance.