THE EFFECTS OF IMMUNOSUPPRESSION ON DEVELOPMENT AND PROGRESSION OF ENDOMETRIOSIS IN BABOONS (PAPIO-ANUBIS)

Objective: To test the hypothesis that immunosuppression increases the development and progression of endometriosis in baboons. Design: Expe rimental controlled study. Setting: Institute of Primate Research, Nai robi, Kenya. Participants: Thirty-two baboons (8 with normal pelvis, 1 0 with spontaneous endometriosis, and 14 with endometriosis induced by intraperitoneal seeding of menstrual endometrium). Intervention: Dail y injection of 0.8 mg/kg IM methylprednisolone and 2 mg/kg azathioprin e for 3 months in 16 baboons (4 with normal pelvis, 5 with spontaneous endometriosis, and 7 with induced endometriosis). No treatment was gi ven to the remaining 16 primates. Main Outcome Measures: The change in number and surface area (mm(2)) of endometriotic lesions was evaluate d by laparoscopy in all baboons after 3 months, in 8 animals with indu ced endometriosis and in 9 primates with spontaneous disease after 7 a nd 12 months, respectively. Results: Immunosuppressed baboons with spo ntaneous endometriosis had a significantly higher number and larger su rface area of endometriotic lesions than nontreated animals. However, immunosuppressed and nontreated primates with induced endometriosis we re comparable with respect to both number and surface area of implants . A transient decrease in typical lesions was noted during immunosuppr ession. Immunosuppression did not cause the development of endometrios is in baboons with previously documented normal pelvis. Conclusion: Im munosuppression may increase the progression of endometriosis in baboo ns with spontaneous disease.