Restoration of ovarian function after allografting of ovarian cortex between genetically non-identical sisters.

BACKGROUND Aggressive chemotherapy generally results in the loss of both endocrine and reproductive functions. For some women, however, oocyte, embryo or ovarian tissue cryopreservation were not proposed at the time. For three such women, orthotopic allotransplantation of fresh ovarian tissue from their genetically non-identical sister was performed. METHODS Three women, aged 20, 15 and 12 years, respectively, underwent chemotherapy and total body irradiation before bone marrow transplantation (BMT), the donor in each case being their HLA-compatible sister. Years later, HLA group analysis revealed complete chimerism, and ovarian allografting was performed, with the ovarian tissue donor being the sister who had already donated bone marrow. No immunosuppressive therapy was administered. No sign of rejection was observed. RESULTS Restoration of ovarian function occurred in all three cases, respectively, 6, 3.5 and 3.5 months after transplantation. The timing of the first estradiol peaks and the persistence of ovarian function were probably related to the primordial follicle density of donor ovarian tissue. CONCLUSIONS Even in the absence of immunosuppressive therapy, ovarian allografting between genetically non-identical sisters allowed restoration of ovarian function in cases where previous BMT from the HLA-compatible sister resulted in full chimerism, avoiding the threat of rejection.