Successful development of vitrified embryonic kidney after laparoscopy transplantation into non-immunosuppressed hosts

Abstract

[EN] Transplantation from living or deceased donors has been limited by donor availability that is opposed to the increasing demand and by the risk of allograft loss rejection and immunosuppressive therapy toxicity. In recent years, xenotransplantation of metanephroi has offered a novel solution for the unlimited supply of human donor organs. However, even if in a most favourable and idyllic situation the organ availability and its demand could be balanced using transplantation of animal embryonic organs, the future of this treatment would still be compromised without proper long-term storage procedure. Thus, based on the ongoing long-term storage necessities, this study was designed to investigate the effect of two specific time window of the metanephroi development (15 days-old and 16 days-old) on the in vivo developmental capacity and the developed morphologically normal glomeruli of vitrified metanephroi in non-immunosuppressive rabbits. Metanephroi originating from 15 and 16 days old rabbit embryos were vitrified using M22 solution and Cryotop® as a device. After three months of storage in liquid nitrogen, metanephroi were transplanted into non-immunosuppressed adult hosts by laparoscopy surgery. Twenty-one days after allotransplantation, 6 (32%) and 7 (35%) new kidneys were recovered. All the new kidneys recovered exhibited significant growth and mature glomeruli. However, histomorphometry analysis revealed that new kidneys developed from 16 days-old metanephroi exhibit a greater degree of maturity compared with 15 days-old metanephroi. Results obtained in the present study point out that, in rabbit model, vitrified 16 days-old metanephroi could be stored in liquid nitrogen, achieving good in vivo developmental capacity and the developed morphologically normal glomeruli after laparoscopy transplantation into non-immunosuppressed hosts.