BACKGROUND: Although the role of male-specific minor histocompatibility antigen H-Y has been increasingly understood in both experimental and clinical organ transplantation, little has been investigated on musculoskeletal tissue transplantation. This study was performed to describe the behavior of male-specific minor histocompatibility H-Y antigen in rat skin and whole limb transplantation.MATERIALS AND METHODS: Using three different strains of inbred rats (Lewis, F344, and Dark Agouti), 75 donor hindlimbs and eighteen skin grafts were isogenically transplanted to the sex-mismatched recipients. Recipients were observed up to 48 weeks postoperatively. Rejection was monitored by the appearance of the skin of the grafted limb and histology. Systemic microchimerism was assessed by polymerase chain reaction using Y-chromosome specific primers.RESULTS: Skin rejection didn't occur in all limb transplant recipients and histology did not show any rejection findings in all components of the limb graft through 48 weeks. Successful functional recovery was expected. Stable and high level of chimerism (>1%) was detected in the lymphoid tissues in nontreated female recipients. Male skin grafts were rejected by Lewis and F344 female recipients within 6 weeks postoperatively. All female skin grafts survived in male recipients.CONCLUSION: Our results suggest that H-Y antigen can induce graft rejection in rat skin graft but causes no rejection reaction in whole limb transplantation. Systemic chimerism may play an important role for acceptance of sex-mismatched limb graft.
Animals DNA