Desensitization in Living Donor Kidney transplantation in South Korea

Chul Woo Yang
Organ Transplant Center, Seoul St. Mary’s Hospital, Seoul, Korea.

INTRODUCTION: Sensitization is an important barrier to successful kidney transplantation. The proportion of highly sensitized patients (PRA>50 %) is 16.8% on waiting-listed patients. Korea also introduced a desensitization program in 2002. Because the number of cases of kidney transplantation after desensitization in each single center is still small, we conducted a nationwide study on the outcomes of kidney transplantation after desensitization in Korea.

METHODS: Six transplant centers that are running desensitization programs were included. The patients who underwent living donor kidney transplantation after desensitization from 2002 to 2010 were retrospectively analyzed. We reviewed patient’s characteristics, detection method of DSA, indication of desensitization, desensitization protocol, graft function, acute rejection rate, graft failure rate and complications.

RESULTS: A total of 86 cases were enrolled. This number corresponded to 1.4% of total living donor kidney transplantation during the same period. Both the number of transplantation cases after desensitization (8 in 2002, 29 in 2010) and the number of transplantation centers involved (1 in 2002, 6 in 2010) have increased over the past 8 years. Thirty-five of these were cases of re-transplantation (40.7 %) and ABO incompatible relationships were combined with sensitization in 13 cases (15.1%). ELISA and Luminex were used for the detection of DSA in 50.8 and 47.7%, respectively. Indications of desensitization were positive complement-dependent cytotoxicity (CDC) cross-match responses [CDC (+), 36.0 %], positive flow-cytometric cross-match responses (FCX (+), 54.7 %), and positive donor-specific antibodies [DSA (+), 8.1 %] with negative cross-match results. The desensitization protocols used pre-transplant plasmapheresis (95.3 %), intravenous immunoglobulin (IVIG, 62.8 %), and rituximab (67.4 %). Most of IVIG therapy (75%) was done using low doses (<0.2 g/kg). Rituximab was administered once or twice. Anti-CD25 antibodies and ATG were used in 53 and 29 cases, respectively. Triple immunesuppression including prednisolone, tacrolimus and mycophenolate was started at 1-2 weeks before transplantation. Acute rejection occurred in 18 patients (20.9 %), graft failure occurred in 4 patients, and the 3-year graft survival rate was 93.8 %. The presence of DSA increased the acute rejection rate (P = 0.015) and decreased the 1-year post-transplant estimated glomerular filtration rate (P = 0.006). Although rejection-free survival rates did not differ significantly between the CDC (+) and FCX (+) groups, the 1-year estimated glomerular filtration rate was lower in the CDC (+) group (P = 0.010). Infectious and significant bleeding complications occurred in 15.5 % and 4.7 % of cases, respectively.

CONCLUSION: Clinical outcome of desensitization in kidney transplantation is good. Characterization of DSA and protocol development is required for improvement of graft and patient survivals.