Correlation of some in vitro and in vivo investigations in rats sensitized with complete Freund's adjuvant.

The survival of peripheral blood lymphocytes following 24 hours of incubation with PPD, migration of peritoneal exudate cells from capillary tubes in the presence or absence of specific antigen in culture medium were investigated at different time intervals after sensitization with complete Freund's adjuvant. Relative regional lymph node weights and enlargement indices were evaluated in all animals. Furthermore, total leucocyte counts and differential counts of different cell types were determined. A correlation between the parameters studied was found, especially between the migration of peritoneal exudate cells and the survival of blood lymphocytes. The kinetic changes in the regional lymph node weights in sensitized animals in relation to those of IFA injected animals can be considered specifically affected. Increasing numbers of peripheral blood leucocytes after sensitization with complete Freud's adjuvant and the finding of increased numbers of monocytes and eosinophils in the initial stages of the observations have been reported in the literature. The results are discussed in relation to problems of tuberculin skin hypersensitivity in ratswhich has long been contradictory in the literature.