Authors' recommendations: Although the actual prevalence of chronic kidney disease in Australia and New Zealand is unknown, it is a substantial health issue in the community. ESRD continues to be a substantial burden to the healthcare system, with ANZDATA indicating that 13,626 individuals were being treated for ESRD in 2003. Considering that the average waiting time for a suitable deceased donor kidney is approximately four years in most Australian states, it is clear that the discrepancy in the number of patients awaiting transplantation and the availability of suitable donor kidneys will worsen if nothing is done to counter this situation. One way of increasing the donor kidney pool is to encourage living kidney donation. While there have been some encouraging results, with live donor transplants accounting for 41% of total transplantations in 2005, researchers have pointed out that approximately 35% of living donors are rejected based on blood group incompatibilities alone.In the advent of the growing need for more donor kidneys, researchers have explored the possibility of living ABOi kidney transplantation as a means of expanding the donor pool. Earlier attempts at ABOi kidney transplantation were generally disappointing and often inconsistent. However, with the introduction of powerful immunosuppressive drugs and various methods of anti-A/B antibody removal, the medical community has once again attempted to overcome the ABOi barrier that has long prevented transplantation between donors and recipients of different blood groups.Five of the included comparative studies reported that ABOi recipients had similar graft survival rates to ABOc recipients; however, three studies reported that ABOi recipients had significantly lower graft survival rates relative to ABOc recipients (Futagawa & Terasaki 2006; Takahashi et al 2002; Tanabe et al 2003). Overall, it appears that ABOi recipient are capable of achieving similar graft survival rates to ABOc recipients. Several interesting observations were highlighted in a few studies. Tanabe et al (2003) noted that high titres of preoperative anti-A/B antibodies were associated with graft loss. In addition to this, one study highlighted that recipient age appeared to be associated with graft survival as well (Takahashi et al 2004). Recipients who were aged ≤15 years had high graft survival rates, while statistical tests indicated that recipients aged ≤29 years had significantly higher graft survival compared to those aged ≥30 years (Takahashi et al 2004).Patient survival was similar between ABOi and ABOc recipients in all of the included studies that reported this outcome. Meanwhile, one study noted that renal function appears to be comparable in ABOi and ABOc patients as well (Genberg et al 2007).Safety outcomes were generally reported in a manner that lacked detail in most of the included studies. Nevertheless, one study reported that ABOi patients tended to have higher overall complication rates compared to ABOc patients (Schwartz et al 2006). In addition to this, surgical complications were significantly higher in ABOi patients and appear to be increased in patients who experienced antibody-mediated rejection. Three studies noted that antibody-mediated rejection was significantly more common in ABOi kidney transplantation, which was not surprising considering the innate risks associated with this procedure. Two studies (Genberg et al 2007; Futagawa & Terasaki 2006) reported that rejection rates were similar between ABOi and ABOc recipients throughout the follow-up period. However, it is important to note that despite similar incidence of rejection at 1 year posttransplantation, ABOi recipients experienced higher graft loss within the first 30 days after transplantation, which was attributed to antibody-mediated rejection (Futagawa & Terasaki 2006). Infectious complications were similar between ABOi and ABOc patients (Grenberg et al 2007).Overall, the evidence indicates that ABOi kidney transplantation is feasible and is capable of achieving similar graft survival rates compared to ABOc transplantation. However, it is important to note that ABOi kidney transplantation is still a relatively new procedure and is continually revised with the introduction of new immunosuppressive drugs or other technological advances. There is continual debate with regards to several aspects of the procedure, such as the necessity of splenectomy and the optimal protocol for ABOi transplantation. The lack of standardisation worldwide continues to prevent comparisons across studies and hinders the elucidation of the most effective transplantation protocol. Furthermore, the large variation in antibody titre measurements as reported by Kotobashi and Saito (2006) highlights the possibility that there are many technical issues that can influence important steps of the transplantation procedure. This inconsistent measurement of antibody titres is one example that may explain the different perceptions among various centres with regards to the ‘suitable/acceptable’ antibody titre on the day on transplantation. In addition to this, the long-term outcomes of new drugs such as MMF, rituximab and tacrolimus that are currently utilised in most modern ABOi transplantation procedures has not been established. It is therefore clear that further research is necessary to determine the most effective protocol for ABOi transplantation. Nevertheless, the evidence available to date on ABOi kidney transplantation is encouraging, and it appears to be a viable procedure to address the growing discrepancy between the pool of suitable donor kidneys and ESRD patients requiring transplantation to survive.

Project Status: Completed

URL for project: http://www.horizonscanning.gov.au/internet/horizon/publishing.nsf/Content/211ABF81A69CA39DCA2575AD0080F3DC/$File/HSR%20ABO%20incompatible%20kidney%20transplantation.pdf

Year Published: 2008

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Australia

Organisation Name: Australian Safety and Efficacy Register of New Interventional Procedures-Surgical

Contact Address: ASERNIP-S 24 King William Street, Kent Town SA 5067 Australia Tel: +61 8 8219 0900

Contact Name: racs.asernip@surgeons.org

Contact Email: racs.asernip@surgeons.org

Copyright: Australian Safety and Efficacy Register of New Interventional Procedures - Surgical (ASERNIP-S)