Background: The primary aim was to review the graft and patient survival of all recipients of a living identical twin donor renal transplant in the United States and United Kingdom, between 1988 and 2004. The secondary aim was to assess their maintenance immunosuppression.
Methods: Data of all the patients who underwent living identical twin donor renal transplantation in the United States and United Kingdom during 1988-2004 were retrieved from United Network for Organ Sharing and UK transplant, respectively. Further data were retrieved by sending letters to the individual transplant units in the United Kingdom.
Results: There were 120 living identical twin donor renal transplants in the United States and 12 in the United Kingdom during the study period. Graft survival was 99.17%, 91.84%, and 88.96% in the US group at 1, 3, and 5 years, respectively, and 83.3%, 83.3%, and 75% in the UK group during the same follow-up period. Patient survival was 100%, 97.01%, and 97.01% in the US group at 1, 3, and 5 years, respectively, and 100% in the UK group during the same 5-year follow-up period. A large number of patients were on some form of immunosuppression.
Conclusions: Graft and patient survival were good in both countries. These results are better than those published in the literature over the previous 20 years. Although phenotypic differences in monozygotic twins can exist, immunosuppression may be unnecessary in all these patients. Ideally, all identical twins who are currently on immunosuppression should undergo zygosity testing to establish whether they should continue the immunosuppression unless they need it for another reason.