Successful prolonged rituximab treatment for post-transplant lymphoproliferative disorder following living donor liver transplantation in a child

Pediatric Gastrointestinal Posttransplant Lymphoproliferative Disorder: Incidence, Clinical Characteristics, and Impact of Major Surgical Interventions Upon Overall Survival

Posttransplant lymphoproliferative disorder (PTLD) is a severe complication of solid organ transplantation. A common site for PTLD development is the gastrointestinal (GI) tract. The purpose of this study was to evaluate the incidence, clinical features, and overall survival of pediatric patients with GI-PTLD, and to assess whether major surgical interventions increased mortality. Records of pediatric transplant patients who developed GI-PTLD between January 2000 and June 2015 were retrospectively reviewed at our institution. Of 814 patients who received solid organ transplants, 34 (4%) developed GI-PTLD. Lung and multiorgan transplants had the highest incidence of GI-PTLD (both 11%). Patients often had multisite GI involvement (47%). Within the first year of transplantation, 38% of the 34 patients developed GI-PTLD. Of the patients with Epstein-Barr Virus-positive disease, 12/22 (55%) presented in the first 12 months of transplantation, compared with only 1/12 (8%) of the patients with Epstein-Barr Virus-negative disease (P=0.002). Major surgical interventions were required in 41% of patients; overall survival rate for these surgical patients was 71%, compared with 60% for patients not requiring major surgical interventions (P=0.49). Despite multimodal treatments, overall survival remains poor for patients with GI-PTLD; however, major surgical intervention did not significantly impact overall survival in this cohort.

Bowel perforation after liver transplantation for biliary atresia: a retrospective study of care in the transition from children to adulthood

PURPOSE

We evaluated the outcomes of liver transplantation (LT) in pediatric and adult patients with biliary atresia (BA). We focused on bowel perforation after LT (BPLT) as the most common surgical complication and analyzed its risk factors.

METHODS

This was a retrospective analysis of 70 BA patients who underwent LT. The patients were divided into three groups according to the timing of LT: within the first year of age (Group A), between 1 and 12 years of age (Group B), and after 12 years of age (Group C). The outcomes of LT and the clinical presentations of BPLT were compared. The surgical variables of patients with and without BPLT were analyzed to assess the risk factors.

RESULTS

The timing of LT did not affect patient survival. The incidence of BPLT was significantly higher in Group C. In Group C, BPLT progressed to severe peritonitis. No cases of BPLT-associated mortality were observed. A multivariate analysis revealed that a prolonged operative time for LT was an independent risk factor (p = 0.03).

CONCLUSION

The clinical course after transplantation was complicated after adolescence. BPLT should be strongly suspected and relaparotomy should be performed in a timely manner for patients undergoing LT after adolescence.

Phenotypic evaluation of B-cell subsets after rituximab for treatment of acute renal allograft rejection in pediatric recipients

BACKGROUND

Recently published pediatric trial of Rituximab for the treatment of CD20+ acute renal allograft rejection (AR) demonstrated transient depletion of circulating/intragraft B cells (Zarkhin et al., Am J Transplant 2008; 8: 2607). In this study, we have evaluated phenotypic definition of circulating B-cell subsets before and after standard of care and B-cell depletional AR therapies.

METHODS

We assessed peripheral B cells by flow cytometry at the time of AR and after AR treatment in 35 pediatric renal transplant recipients: 17 patients with AR who received Rituximab (R-AR; n=11) or steroid pulsing (S-AR; n=6), 18 stable patients with stable graft function with (iSTA; n=10) or without interval infection (hSTA; n=8), and 3 healthy volunteers.

RESULTS

Infections increased memory (P=0.02) and CD19+/CD27⁻/IgD⁻ double negative (DN) B cells (P=0.02) and decreased naive B cells (P=0.01) in iSTA group compared to hSTA patients. Decrease in naive/memory B cells ratio at AR was observed compared with hSTA patients (P=0.01). One year after AR treatment, S-AR patients had persistently lower naive/memory B-cell ratio (P=0.01) and higher DN B cells (P=0.0001) than hSTA patients, whereas after R-AR treatment naive/memory B-cell ratio (P=0.6) and DN B cells (P=0.13) recovered to levels of hSTA patients. R-AR patients with sustained AR resolution (n=8) had trend toward better graft survival (P=0.06) and higher naive B cells (P=0.004) than R-AR relapsers (n=3).

CONCLUSIONS

Increase in circulating memory B cells was seen in pediatric patients at AR. B cells persist as memory after S-AR treatment, whereas Rituximab resulted in repopulation of mostly naive B cells. The heterogeneity in B-cells reconstitution after rejection therapies deserves further investigation as a possible means to follow the clinical and immunologic outcomes of graft rejection.

Update on EBV monitoring, detection and therapy in PTLD after solid organ transplant

EBV remains an important cause of morbidity and mortality in solid organ transplant (SOT) recipients. Post-transplant lymphoproliferative disorder is the most severe complication of EBV infection in SOT patients. While EBV viral load monitoring can be used to predict SOT patients at high risk of post-transplant lymphoproliferative disorder (most effectively for patients who are EBV seronegative prior to transplant), interpretation and management of these results may be confusing and can be complex. Monitoring to guide preemptive reduced immunosuppression has contributed to the decreased incidence of post-transplant lymphoproliferative disorder in SOT recipients. For the treatment of post-transplant lymphoproliferative disorder, increasing evidence supports the use of the anti-CD20 antibody rituximab. However, experience to date suggests that use of this agent may not prevent recurrence of tumor or improve cell-mediated immune responses to EBV. Future investigation of EBV-specific T-cell responses as an adjunct to monitoring and adoptive transfer of EBV-specific cytotoxic T lymphocytes appear likely in further attempts to limit the consequences of EBV infection in the SOT population.

Surgical complications after living donor liver transplantation in patients with biliary atresia: a relatively high incidence of portal vein complications

BACKGROUND/PURPOSE

The aim of this study is to present the surgical complications in living donor liver transplantation (LDLT) for biliary atresia (BA) as a treatment for end stage liver disease.

PATIENTS AND METHODS

Twenty-nine LDLTs were performed in patients with BA between October 1996 and April 2008 in Department of Pediatric Surgery at Kyushu University Hospital. The initial immunosuppression was a combination of tacrolimus and steroids.

RESULTS

Twenty-eight of 29 cases with BA, who previously underwent Kasai's operation and LDLT was performed at a median age of 9.1 years (range 7 months to 28 years). Only one case was performed primary LDLT. Post-transplant complications included portal vein complications (n = 5), three of which successfully treated by Rex-shunt or ballooning. Others were bile leakage (n = 4), intestinal perforation (n = 4), and so on. The overall survival rate was 86.2% (25/29). One patient died of chronic rejection, surgical complications after LDLT in BA while others died of sepsis, multi-organ failure, and brain hemorrhage.

CONCLUSION

The incidence of portal vein complications and intestinal perforations was relatively high in LDLT for BA, possibly due to inflammation of the hepatoduodenal ligament and colonic adhesion to the liver. It is important to make an accurate diagnosis at an early stage and provide appropriate treatment.

A randomized, prospective trial of rituximab for acute rejection in pediatric renal transplantation

We report 1-year outcomes of a randomized study of Rituximab versus standard-of-care immunosuppression (Thymoglobulin and/or pulse steroids) for treatment of biopsy confirmed, acute transplant rejection with B-cell infiltrates, in 20 consecutive recipients (2-23 years). Graft biopsies, with Banff and CADI scores, CD20 and C4d stains, were performed at rejection and 1 and 6 months later. Peripheral blood CMV, EBV and BK viral loads, graft function, DSA, immunoglobulins, serum humanized antichimeric antibody (HACA) and Rituximab, and lymphocyte counts were monitored until 1 year posttreatment. Rituximab infusions were given with a high index of safety without HACA development and increased infections complications. Rituximab therapy resulted in complete tissue B-cell depletion and rapid peripheral B-cell depletion. Peripheral CD19 cells recovered at a mean time of approximately 12 months. There were some benefits for the recovery of graft function (p = 0.026) and improvement of biopsy rejection scores at both the 1- (p = 0.0003) and 6-month (p < 0.0001) follow-up biopsies. Reappearance of C4d deposition was not seen on follow-up biopsies after Rituximab therapy, but was seen in 30% of control patients. There was no change in DSA in either group, independent of rejection resolution. This study reports safety and suggests further investigation of Rituximab as an adjunctive treatment for B-cell-mediated graft rejection.