Post-listing survival for highly sensitised patients on the UK kidney transplant waiting list: a matched cohort analysis

Abstract

Background: More than 40% of patients awaiting a kidney transplant in the UK are sensitised with human leucocyte antigen (HLA) antibodies. Median time to transplantation for such patients is double that of unsensitised patients at about 74 months. Removing antibody to perform an HLA-incompatible (HLAi) living donor transplantation is perceived to be high risk, although patient survival data are limited. We compared survival of patients opting for an HLAi kidney transplant with that of similarly sensitised patients awaiting a compatible organ.

Methods: From the UK adult kidney transplant waiting list, we selected crossmatch positive living donor HLAi kidney transplant recipients who received their transplant between Jan 1, 2007, and Dec 31, 2013, and were followed up to Dec 31, 2014 (end of study). These patients were matched in a 1:4 ratio with similarly sensitised patients cases listed for a deceased-donor transplant during that period. Data were censored both at the time of transplantation (listed only), and at the end of the study period (listed or transplant). We used Kaplan-Meier curves to compare patient survival between HLAi and the matched cohort.

Findings: Of 25 518 patient listings, 213 (1%) underwent HLAi transplantation during the study period. 852 matched controls were identified, of whom 41% (95% CI 32-50) remained without a transplant at 58 months after matching. We noted no difference in survival between patients who were in the HLAi group compared with the listed only group (log rank p=0·446), or listed or transplant group (log rank p=0·984).

Interpretation: Survival of sensitised patients undergoing HLAi in the UK is comparable with those on dialysis awaiting a compatible organ, many of whom are unlikely to be have a transplant. Choosing a direct HLAi transplant has no detrimental effect on survival, but offers no survival benefit, by contrast with similar patients studied in a North American multicentre cohort.

Funding: UK National Health Service Blood & Transplant and Guy's & St Thomas' National Institute for Health Research Biomedical Research Centre.