Studies on IgG subclass antibodies in asthmatics with late asthmatic responses Part 1. Serum antigen-specific IgG subclass antibodies in asthmatics with late asthmatic response

The immediate asthmatic response is mainly induced by IgE-dependent mechanisms. However, the late asthmatic response (LAR) is induced by inhalation of antigens without the participation of antigen-specific IgE antibodies in some asthmatics, especially in intractable asthma induced by Candida antigen. To elucidate the relationship between antibodies and those bronchial responses, the antigen-specific IgG subclass antibodies in sera from asthmatics were measureed and compared with IgE antibody. The avidin-biotin ELISA (enzyme-linked immunosorbent assay) method was established for the measurement of specific IgG and IgG subclass antibodies to mite or Candida antigen. Serum levels of IgG and IgG1 antibodies to mite and Candida antigen in bronchial asthmatics were significantly higher than those in healthy subjects (p<0.01). Bronchial asthmatics who were tested with inhalation of house dust or Candida antigen were divided into group A (higher levels of serum IgG1 antibody) and group B (lower levels of serum IgG1 antibody). The percentage of LAR including DAR after inhalation of house dust antigen in group A were significantly higher than those in group B (p<0.01). The percentages of LAR and LAR including DAR after inhalation of Candida antigen in group A were significantly higherSerum levels of house du than those in group B(p<0.01). Serum levels of antigen-specific IgG and IgG1 antibodies in asthmatics with LAR after inhalation of house dust or Candida antigen were significantly higher than those in asthmatics with IAR or non-responders (p