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

Abstract

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, in which 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 and developing morphologically normal glomeruli after laparoscopy transplantation into non-immunosuppressed hosts.

Sildenafil Citrate Enhances Renal Organogenesis Following Metanephroi Allotransplantation into Non-Immunosuppressed Hosts

“…This concept is similar to that used in kidney transplantation from paediatric donors, in which both kidneys are transplanted in bloc into adult recipients to guarantee acceptable glomerular filtration rates [ 53 , 54 ]. This strategy should be combined with those designed to avoid hydronephrosis [ 18 ], or others developed in our group, such as the minimally invasive laparoscopic transplantation procedure [ 38 , 55 ], effective banking protocols [ 56 , 57 , 58 ], and, now, the use of SC. All these strategies, in conjunction, could constitute a path increasingly consolidated by which metanephroi xenotransplantation could provide transplantable renal grafts to treat patients with ESRD.…”