Demonstration in Vitro of Delayed Hypersensitivity in Experimental Allergic Orchitis in Guinea-Pigs

Summary. Cells in the peritoneal exudate obtained from guinea-pigs within 7 days of sensitization with testicular homogenate emulsified in complete Freund's adjuvant, showed inhibition of migration when cultured in the presence of the supernatant from the testis homogenate. Simultaneously, the first signs of orchitis were observed. Delayed skin tests became positive only 19 days after sensitization when the orchitis was fully developed. Intertubular infiltration was found in few animals without any apparent relationship to the lesions of the seminiferous tubules. Anaphylactic antibodies were detected within 33 days of sensitization as shown by anaphylactic skin reaction and passive cutaneous anaphylaxis. The macrophage migration test appears to detect delayed hypersensitivity earlier than the delayed skin reaction in the experimental conditions used.