Successful living donor renal transplantation despite ABO incompatibility and a positive crossmatch

ABO incompatible kidney transplantation

PURPOSE OF REVIEW

Although ABO incompatible kidney transplantation is increasingly recognized as effective, the procedure is still evolving. The purpose of this review is to summarize recent advances in this area.

RECENT FINDINGS

Short to intermediate-term outcome appears good, although long-term results are still preliminary. Pretransplant risk stratification based on antidonor antibody titer may be of limited value. Splenectomy, previously reported to be an important component of ABO incompatible transplantation, appears to be avoidable under many circumstances. The wider implementation of A2 blood group incompatible transplantation shortens waiting time for deceased donor transplantation of blood group B recipients without significantly disadvantaging others. The diagnosis of acute humoral rejection has become clearer following the recognition that C4d deposition commonly occurs in well functioning ABO incompatible allografts. The long-term implications of acute humoral rejection appear substantial even following successful acute therapy, with a significant percentage of patients developing chronic humoral rejection manifested as transplant glomerulopathy. Finally, although ABO incompatible transplantation entails increased expense, when compared with maintenance dialysis and taking into account the health related quality of life benefits of a successful transplant, it is clearly cost effective.

SUMMARY

ABO incompatible kidney transplantation is an effective therapy, and will become more widely implemented in the future.

Plasmapheresis in nephrology: an update

PURPOSE OF REVIEW

In the past, recommendations for the use of plasmapheresis were based on findings reported from pilot studies or anecdotes. New results from several randomized controlled trials have changed the indications for the use of plasma exchange.

RECENT FINDINGS

A large randomized controlled study of patients with antineutrophil cytoplasmic antibody associated vasculitis showed benefit of plasmapheresis in those with severe renal disease. Patients receiving plasmapheresis compared with methylprednisolone as adjuvant therapy were more likely to be alive and dialysis independent. Plasmapheresis, following publication of a recent randomized controlled trial, should no longer be used for patients with myeloma and acute renal failure. Standard therapy with five to seven plasma exchanges was compared with standard therapy alone. There was no difference in those patients reaching the composite endpoints between the two treatments. New indications include desensitization protocols, using plasmapheresis and intravenous immunoglobulin, which have allowed transplantation across immunological barriers. Highly sensitized patents and ABO incompatible patients compared with their potential donors are now being transplanted with excellent results. Studies still need to be done to assess the best desensitization protocol.

SUMMARY

The use of plasmapheresis requires further validation by randomized clinical trials. Recent published trials should alter practice but further studies are required.

First two ABO-incompatible living renal transplantations using splenectomy, rituximab, plasmapheresis and IVIG as a preconditioning regimen: a single center experience in the Balkans

BACKGROUND

Due to the growing organ shortage in the Balkans and still underdeveloped cadaver transplantation, we started accepting living expanded criteria renal donors including elderly, marginal and unrelated donors (spouses, etc). The ABO-incompatible renal transplantation was initiated last year. The first two successful cases are presented.

METHODS

A 40-yr-old mother (blood group A1B) and a 57-yr-old husband (blood group B) were considered as suitable donors for an 18-yr-old daughter (blood group B) and a 52-yr-old wife (blood group O). Both the recipients had a relatively long dialysis treatment before the surgery. The anti-A1 and anti-B titer of isoaglutinins was 1 : 64 in both the recipients before the procedure. A routine laparoscopic splenectomy was performed 40 and 45 days before the transplantation, without any complications. In the 10 days pre-conditioning period, rituximab was administered in a single dose of 375 mg/m2. At the same time four to five plasmaphereses were performed to reduce the isoaglutinins to below 1 : 4. On the last night before the surgery intravenous immunoglobulin (IVIG) in a dose of 0.5 g/kg/bw was administered. Standard induction and maintenance therapy was introduced (Dacllizumab, CyA-Neoral, MMF and steroids) according to the accepted policy in our transplant center. The routine plasmaphereses were performed in the first 2 weeks after transplantation to keep the isoaglutinins titer below 1 : 8.

RESULTS

Ten and 6 months after the surgery both recipients are doing well. Their graft function remains stable (actual serum creatinin 140 and 230 microm/L, respectively). In the 1 month protocol biopsy a subclinical cellular and mild vascular rejection occurred, and both recipients were treated by steroid pulse therapy. One to two additional plasmaphereses were performed. The regularly monitored anti-A1 and anti-B isoaglutinins titer was kept below 1 : 8 during a period of follow-up.

CONCLUSION

The first short-term results fully justify the ABO-incompatible living renal transplantation. The authors consider ABO-incompatible transplantation as a safe and promising procedure which may, together with expanded criteria living donors, ameliorate the actual donor shortage in the region.

Lack of correlation between results of ABO-incompatible living kidney transplantation and anti-ABO blood type antibody titers under our current immunosuppression

In this study, we examined the impact of preoperative anti-A/B antibody titers on the results of ABO-incompatible living kidney transplantation (LKT). In all, 167 recipients underwent ABO-incompatible LKT at our institution between 1989 and 2002. These patients were subdivided into those transplanted under cyclosporine with azathioprine or mizoribine (Group 1, n=78) and those transplanted under tacrolimus or mycophenolate mofetil (Group 2, n=89). Overall patient survival at 5 and 10 years was 93.8% and 88.0%, respectively. Overall graft survival at 5 and 10 years was 76.9% and 55.9%, respectively. Graft survival in the patients with anti-A/B IgG titers over 1:128 was significantly lower in group 1, whereas no significant correlation between the anti-A/B IgG titers and graft survival was found in group 2. In conclusion, no correlation between anti-A/B antibody titers and the results of ABO-incompatible LKT was seen after tacrolimus or mycophenolate mofetil application.

Extending options for highly sensitized patients to receive a suitable kidney graft

Highly sensitized patients (anti-HLA) on the kidney waiting list wait longer for a suitable crossmatch negative organ. At the moment there are two strategies to enhance transplantation of these patients. One approach is the determination of acceptable HLA mismatches and application of this knowledge for the selection of crossmatch negative donors, and the second is the desensitization of patients with intravenous immunoglobulin-based protocols to enable transplantation of an organ from a donor towards which antibodies were originally present. Both approaches have advantages and disadvantages and are only successful in a proportion of the patients. The optimal solution is an integrated strategy whereby desensitization is used for those patients for whom the acceptable mismatch approach is not successful.