Evaluation of the pulmonary immune response by analysis of bronchoalveolar fluids obtained by serial lung lavage.

Lavage fluids were obtained from Beagle dogs by serial bronchoalveolar lavage from immunized and control lung lobes 3-21 days after local deposition of sheep red blood cells. Results showed that immunized lobes contained more total protein, albumin, IgG and antigen-specific antibody than did unimmunized control lobes or lobes that received autologous red cells in saline. Antigen-specific antibody was present in the lavage fluid from 7 through 21 days after immunization. Mercaptoethanol treatment of lavage fluid had little effect on the antibody titer, suggesting that IgG, and possibly IgA, were the predominant immunoglobulin classes in the antigen-specific antibody pool throughout the course of the serial lavage study. The data suggest that most of the antigen-specific antibody was made locally by cells in the lung.