Specific hypo-responsive granulomatous tissue reactions in Brugia pahangi-infected jirds.

Two types of experiments were used to study the degree of tissue responsiveness which occurred in Brugia pahangi-infected jirds. In experiment 1, the severity of lymphatic lesions which developed following subcutaneous infection of jirds which has existing intraperitoneal infections was compared to the severity of lymphatic lesions that developed following subcutaneous infection of jirds without previous infections. In experiment 2, comparisons were made of the sizes of granulomas which formed in the lungs around cyanogen bromide-activated Sepharose 4B beads coupled with B. pahangi antigen, which were inoculated intravenously into jirds which: 1. had existing lymphatic infections; 2. were uninfected. Results of both experiments indicated that jirds with intraperitoneal or lymphatic infections of B. pahangi of 120 to 160 days duration were significantly less responsive to B. pahangi or B. pahangi antigens as measured by pathologic tissue reactions than were uninfected jirds. The sizes of granulomas which formed around beads coupled to B. pahangi antigen in noninfected and nonsensitized jirds suggest that this worm material may contain factors which nonspecifically enhance the granulomatous inflammatory reaction.