First promising results of ciat: A new kidney exchange program for difficult-to-match patients

Purpose: Computerised Integration of Alternative Transplantation (CIAT) programs was developed to increase the chances of highly immunized (HI) and longwaiting (LW) kidney transplant candidates. CIAT integrates AB0-desensitisation, HLAdesensitisation, donor-exchange, altruistic and domino-paired donation. Strict criteria were defined for selected HI (sHI) patients. sHI patients are given priority, and dependent on titers, AB0-incompatible (AB0i) and/or HLA-incompatible matching (HLAi) is allowed. Long-waiting (LW) blood type 0 candidates (>2y dialysis) can opt for an AB0i match. In a 1 center simulation of 2015-2016 , CIAT matched 8 out of 20 participating sHI patients. Desensitisation was indicated for 3 patients: 1 AB0i, 1 HLAi and 1 both AB0i and HLAi. Five transplantations could be done without desensitisation. Methods: A 1 center pilot was established from 2017 onwards to gain logistic experience, to test the algorithm and to optimize the program. Protocols have been created and pathways were developed for recognition of sHI and LW candidates, for logistics and patient information. Results: Between 2017-2020, 115 couples, 20 unspecified donors and 18 sHI patients were included in CIAT, 56 transplantations were accomplished: 52 compatible, and 4 AB0i transplantations. 10 sHI patients were matched. 2 HLAi transplantations were cancelled during COVID. 8 were transplanted: 5 compatible and 3 AB0i transplantations. Their median vPRA was 95% (range 85-100), median age 54 years (range 26-76) and median waiting time 5y(range 2y- 9y). 12 LW patients were transplanted: 11 compatible and 1 AB0i, median waiting time 3y (2y- 6y). 5 unspecified donors donated to the waitlist, 15 initiated chains ( 9 with 1 and 6 with 2 incompatible pairs). There were 6 kidney-exchange cycles with 2 and 1 with 3 incompatible pairs. CIAT runs were performed between national runs. In the same period 16 pairs were transplanted through the national exchange program, no sHI patients were matched. Conclusions: The pilot yields very promising results for the sHI and LW candidates. Negotiations on national implementation, replacing the current kidney exchange program, are ongoing. Extrapolation of our results to national size would mean between 16-20 sHI candidates transplanted per year. Apart from an enormous health-gain for sHI and LW patients this means a vast reduction of healthcare costs.