Login to Access Video or Poster Abstract: MP06-06
Sources of Funding: none

Introduction

Recently, desensitization therapy became more widely used in ABO incompatible kidney transplantation (ABOi-KTx). A body of evidence has been accumulated suggesting that anti-A, anti-B antibody titer is not necessarily a good indicator for the development of acute antibody mediated rejection (AMR) or for favorable or unfavorable patient outcome. We have omitted the pre-transplant antibody removal in selected patients since 2010 at out institution.

Methods

Twenty-two patients with baseline antibody titer ≤ 1:64 received ABOi-KTx without pre-transplant antibody removal between 2010 and 2015 (Group 1). Historical control group consisted of 22 patients with baseline antibody titer ≤ 1:64 who received ABOi-KTx with 2 or 3 sessions of pre-transplant antibody removal before 2009 (Group 2). All patients were treated with calcineurin inhibitor (CNI), mycophenolate mofetil (MMF), and methylprednisolone (MP) starting 4 weeks before ABOi-KTx. Two doses of rituximab (100mg) were given in both groups before ABOi-KTx. Protocol biopsies were performed 1-2 month after ABOi-KTx.

Results

Recipient and donor age, sex, the number of HLA mismatch were not significantly different between the 2 groups. Baseline antibody titers (IgG) were 1:17 (range 0-64) and 1:18 (range 0-64) in Group 1 and 2, respectively (P=0.81). Antibody titers at the day of ABOi-KTx were 1:10 (range 0-32) and 1:8 (range 0-32) in Group 1 and 2, respectively (P=0.43). Five year graft survival were 100 % in both groups. Serum creatinine levels at 3 years after ABOi-KTx were 1.25±0.75 and 1.46±0.43 mg/dl in Group 1 and 2, respectively (P=0.39). Biopsy proven AMR occurred in 2 patients of Group 1 (9.1%) and 3 patients of Group 2 (13.6%). AMR in these patients was abrogated with steroid pulse therapy with or without plasma exchange. There was no significant difference in protocol biopsy results of Banff 2013 criteria between the 2 groups. C4d score more than 2 was detected in 72 % in Group 1 and 75 % in Group 2 (P=0.97). IgM deposition on peritubular capillary was seen in 38.8 % in Group 1 and 60.0 % in Group 2 (P=0.25).

Conclusions

Pre-transplant antibody removal is not required for patients whose serum antibody titers are ≤ 1:64 in ABOi-KTx as long as desensitization therapy consisting of CNI, MMF, MP and retuximab is implemented appropriately.

Funding

none