Posttransplantation lymphoproliferative disorder after pediatric solid organ transplantation: experiences of 20 years in a single center

The IPTA Nashville consensus conference on post-transplant lymphoproliferative disorders after solid organ transplantation in children: IV-consensus guidelines for the management of post-transplant lymphoproliferative disorders in children and adolescents

The International Pediatric Transplant Association convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorders (PTLD) after pediatric solid organ transplantation. This report addresses the outcomes of deliberations by the PTLD Management Working Group. A strong recommendation was made for reduction in immunosuppression as the first step in management. Similarly, strong recommendations were made for the use of the anti-CD20 monoclonal antibody (rituximab) as was the case for chemotherapy in selected scenarios. In some scenarios, there is uncoupling of the strength of the recommendations from the available evidence in situations where such evidence is lacking but collective clinical experiences drive decision-making. Of note, there are no large, randomized phase III trials of any treatment for PTLD in the pediatric age group. Current gaps and future research priorities are highlighted.

Post-transplant lymphoproliferative disorder associated Epstein-Barr virus DNAemia after liver transplantation in children: Experience from single center

The most prevalent malignancy that complicates both adult and pediatric solid organ transplantation is post-transplant lymphoproliferative disorder (PTLD). This study aimed to analyze the clinical and pathological characteristics, treatments, and outcomes of Epstein-Barr virus (EBV) DNAemia and PTLD in pediatric liver transplant recipients. A retrospective chart review was performed on 112 patients less than 18 years of age who underwent isolated orthotopic liver transplantation (OLT) between 2010 and 2022 at Ege University Children's Hospital. Data gathered for 1-year post-OLT included age at OLT, EBV, immunoglobulin (Ig)M/IgG status of the donor and recipient, indication for OLT, induction regimen, all immunosuppression levels, date and result of EBV polymerase chain reaction testing, rejection episodes documented by liver biopsy, and the development of PTLD. Forty-nine patients (43.75%) developed EBV DNAemia (median interval from surgery: 2 months, min-max: 2-36), of which 43 (87.8%) grafts came from living donors, and 6 (12.2%) came from deceased donors. Nine (18.4%) patients died during follow-up, and eight (16.3%) developed PTLD. Of these 8 patients; five patients developed EBV-related disease, one child developed hemophagocytic lymphohistiocytosis, one developed aplastic anemia, and one child developed B cell lymphoma. When PTLD patients and without-PTLD patients were compared, pediatric intensive care unit hospitalization, abnormal bone marrow biopsy findings, lymphadenopathy, age at diagnosis of EBV DNAemia, EBV viral load, tacrolimus (FK 506) pre-infection, were higher and tacrolimus 1-month levels were lower in patients with PTLD (p < 0.05). In logistic regression analysis, we showed that the age at diagnosis of EBV DNAemia was significantly higher in children with PTLD (p = 0.045; OR: 1.389; 95% CI: 1.007-1.914). PTLD is a rare but severe complication associated with EBV after OLT. This study demonstrated that PTLD is associated with older age, higher tacrolimus blood levels before EBV DNAemia, and higher peak EBV viral load at 1 month of EBV DNAemia.

Post-transplant lymphoproliferative disorder in pediatric liver transplant recipients: Experience from a South African transplant center

INTRODUCTION

Post-transplant lymphoproliferative disorder (PTLD) is a clinically heterogeneous potentially fatal complication of pediatric liver transplantation (PLT). We determined the prevalence, complications, and associated factors for PTLD in PLT recipients from Wits Donald Gordon Medical Centre, South Africa from January 2012 to August 2019.

METHODS

We performed a retrospective record review of 150 PLT recipients.

RESULTS

Histologically proven PTLD occurred in 17/150 PLT recipients (11.3%). Children with PTLD were significantly younger at transplant (17.9 vs. 32.7 months, p = 0.001) with a significantly higher prevalence of obstructive etiology (17/17 vs. 81/133, p = 0.001). Fifteen (88.2%) children with PTLD were Epstein-Barr virus (EBV) seronegative at transplant. High post-transplant EBV viral load at a threshold value of 4.8 log10 DNA copies/mL (sensitivity: 80.0% [95% confidence interval {CI}, 46.7%-100.0%]; specificity: 73.1% [95% CI 42.3%-93.3%; area under the curve {AUC} 75.8%]) and low post-transplant albumin levels at a threshold value of 21.5 g/L (sensitivity: 70.6% [95% CI, 41.2%-94.1%]; specificity: 85.7% [95% CI, 60.4%-94.5%; {AUC} 74.8%]) were associated with PTLD. The prevalence of cytomegalovirus (CMV) disease was significantly higher in children who developed PTLD versus non-PTLD (12/17 vs. 18/133; p < 0.001). CMV disease and the combination of post-transplant high EBV viral load and low albumin were independently associated with an increased risk of developing PTLD. Four (23.5%) children with PTLD died, however, survival was equivalent to non-PTLD PLT (p = 0.580).

CONCLUSION

The prevalence of PTLD in our cohort mirrors international cohorts, with mortality similar to non-PTLD PLT recipients.

Post-transplant Lymphoproliferative Disorder in Pediatric Liver Transplantation: A Population-based Study from Shiraz, Iran

Background: This study aimed to determine the prevalence of post-transplant lymphoproliferative disorder (PTLD) based on the clinical and epidemiological characteristics of donors and pediatric transplant recipients. Methods: This cross-sectional study was conducted on the patients who had experienced liver transplantation at Shiraz Transplant Center, Shiraz, Iran, from April 2007 to March 2017. Data on the epidemiological characteristics, underlying diseases, dosage of immunosuppressive drugs, and duration of drug consumption from the time of liver transplantation until the onset of PTLD for transplant recipients, and donors’ age, sex, and family relationship with recipients were collected using a data-gathering form. Log rank test was employed to determine the variations in the distribution of survival in different sex and age groups. Results: The study findings indicated that 49 out of the 1207 children who had undergone liver transplantation developed PTLD, revealing a prevalence of 4%. The results showed no significant relationship between gender and the incidence of PTLD (P = 0.13). However, the mean age of the cases with PTLD was 4.93 ± 1.07 years at the time of transplantation, while non-PTLD patients showed a higher mean age at that time (7.80 ± 5.54). The mean dose of the immunosuppressive drugs (dose/kg) consumed by the recipients was as follows: tacrolimus = 0.2753 ± 0.23435, prednisolone = 0.6761 ± 0.62218, cellcept = 0.0724 ± 0.12963, and sirolimus = 0.1078 ± 0.08813. The average consumption period of the above-mentioned drugs from the time of transplantation until the onset of PTLD was 14.7 ± 14.409 months. Based on the results, the five-year survival rate was much lower in the patients with PTLD compared to the non-PTLD patients (31% Vs. 72.7%). The survival distribution was significantly different based on sex and age groups (P = 0.59 and P = 0.06, respectively). Conclusions: The prevalence of the clinical and epidemiological features of the PTLD in the patients under the present investigation was similar to those of the patients in other hospitals. Recognizing the clinical and epidemiological characteristics of transplant recipients with and without PTLD and donors can provide a basis for managing these patients.

Course of renal allograft function after diagnosis and treatment of post-transplant lymphoproliferative disorders in pediatric kidney transplant recipients

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) is a life-threatening complication in renal transplant recipients. Immunomodulatory and chemotherapeutic treatment potentially affect allograft function. The aim of this study was to evaluate graft function of pediatric kidney transplant recipients following diagnosis and standardized treatment of PTLD.

METHODS

Patients were identified from the German Ped-PTLD registry, and data on renal function were retrospectively retrieved from patient charts. For PTLD treatment, immunosuppressive therapy was reduced and all children received rituximab (375 mg/m² ) for up to six doses. Two patients required additional low-dose chemotherapy. Renal allograft function was monitored by consecutive measurements of estimated glomerular filtration rate (eGFR) at defined time points. Follow-up was up to 60 months after PTLD.

RESULTS

Twenty patients were included in this cohort analysis. Median time from transplantation to PTLD was 2.4 years. Histopathology showed monomorphic lesions in 16 and polymorphic in 4 patients. Two patients experienced PTLD relapse after 2 and 14 months. Range-based analysis of variance showed stable allograft function in 17 of 20 patients (85%). Mean eGFR increased during early treatment phase. One patient experienced graft rejection 5.3 years after diagnosis of PTLD. Another patient developed recurrence of primary renal disease (focal-segmental glomerulosclerosis) and lost his renal allograft 3.8 years post-transplant (2.0 years after PTLD diagnosis).

CONCLUSION

Treatment of PTLD with rituximab with or without low-dose chemotherapy in combination with reduced immunosuppression, mostly comprising of an mTOR inhibitor-based, calcineurin inhibitor-free regimen, is associated with stable graft function and favorable graft survival in pediatric renal transplant patients.

De-novo malignancies after kidney transplantation: A long-term observational study

Background

De-novo malignancies after kidney transplantation represent one major cause for mortality after transplantation. However, most of the studies are limited due to small sample size, short follow-up or lack of information about cancer specific mortality.

Methods

This long-term retrospective analysis included all adult patients with complete follow-up that underwent kidney transplantation between 1995 and 2016 at our centre. All patients with diagnosis of malignancy excluding non-melanoma skin cancer (NMSC) were identified and a matched control group was assigned to the kidney transplant recipients with post-transplant malignancies.

Results

1417 patients matched the inclusion criteria. 179 malignancies posttransplant were diagnosed in 154 patients (n = 21 with two, n = 2 patients with three different malignancies). Mean age at cancer diagnosis was 60.3±13.3 years. Overall incidence of de-novo malignancies except NMSC was 1% per year posttransplant. Renal cell carcinoma was the most common entity (n = 49, incidence 4.20 per 1000 patient years; cancer specific mortality 12%), followed by cancer of the gastro-intestinal tract (n = 30, 2.57; 50%), urinary system (n = 24, 2.06; 13%), respiratory system (n = 18, 1.54; 89%), female reproductive system (n = 15, 1.29; 13%), posttransplant lymphoproliferative disorders and haematological tumours (n = 14, 1.20; 21%), cancers of unknown primary (n = 7, 0.60 100%) and others (n = 22, 1.89; 27%). Male sex, re-transplantation and time on dialysis were associated with de-novo malignancies after transplantation.

Conclusion

De-novo malignancies continue to be a serious problem after kidney transplantation. To improve long-term outcome after Kidney transplantation, prevention and cancer screening should be more tailored and intensified.

A multicenter survey on post-transplant lymphoproliferative disorders in pediatric heart transplant recipients: A case for development of consensus guidelines for screening, surveillance, and treatment?

Post-transplant lymphoproliferative disorders (PTLD) are the main malignancy seen after pediatric heart transplant and are a significant cause of morbidity and mortality. Prior to the development of detailed guidelines, we sought to identify trends in screening, diagnosis, and treatment of pediatric PTLD. All Pediatric Heart Transplant Society (PHTS) institutions were surveyed. No identifiable patient information was shared. From 56 PHTS centers, 22 responses were received (39.3%). 100% agree PTLD cannot be diagnosed solely based on elevated Epstein-Barr virus (EBV) load. All respondents routinely screen for EBV by blood PCR, but frequency of screening varies. There was intermediate consensus regarding the use of computed tomography (CT) and/or positron emission tomography (PET) in surveillance management for PTLD. Most centers require a diagnostic biopsy before initiating new treatment for PTLD (14 of 18, 77.8%), but many reduce immune suppression based on elevated EBV without pathologic PTLD (16 of 22, 72.7%). Beyond immune modulation, rituximab is most commonly used (9 of 13, 69.2%). Consultation with oncology is common (17 of 17, 100%), but timing varies widely. Our survey highlights significant elements of agreement and significant practice variation among PHTS institutions regarding pediatric PTLD. Reduction of immune suppression prior to pathologic diagnosis of PTLD is a common management strategy. When this fails, rituximab is used, but is most often reserved until after confirmation of the diagnosis. Oncology subspecialists are commonly involved in these cases. Our findings highlight the need to develop improved guidelines for evaluation and treatment of pediatric PTLD.

Post-Transplant Lymphoproliferative Diseases in Pediatric Kidney Allograft Recipients with Epstein-Barr Virus Viremia

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) is one of the major complications of organ transplantation, especially in children with Epstein-Barr virus (EBV) viremia (EV). We performed a retrospective study to evaluate risk factors for PTLD in children with EV.

METHODS

Among 199 pediatric kidney transplantation (KT) recipients at our center from January 2001 to October 2015, records of those with EBV viral loads of > 1,000 copies/mL and/or PTLD were reviewed.

RESULTS

Diagnosis of PTLD was made in seven patients (PTLD group), and 39 patients had EV only (EV only group). The median time from KT to EV and PTLD diagnosis was 6.7 (range 0.4-47.8) months and 8.2 (range, 2.8-98.9) months, respectively. There were no significant differences between the groups in terms of sex, age at transplantation, donor type, EBV viral load, or EV-free duration after KT. Higher tacrolimus level before EV (hazard ratio, 44.5; P = 0.003) was an independent risk factor for PTLD in multivariate Cox regression analysis. Six patients with a high EBV load (median 171,639 copies/mL) were treated with preemptive rituximab (RTX) therapy, resulting in transient reduction of EBV load. None of these patients developed PTLD (median follow-up 51.5 months); however, two had neutropenia and two developed infection requiring hospital admission.

CONCLUSION

In pediatric KT recipients, higher tacrolimus levels were associated with a higher incidence of PTLD. Conversely, those who received preemptive RTX for EV did not develop PTLD.

Pediatric Outcomes in Transplant: PersOnaliSing Immunosuppression To ImproVe Efficacy (POSITIVE Study): The Collaboration and Design of a National Transplant Precision Medicine Program

Background

Despite age-related differences in biology, physiology, and behavior, transplant immunosuppression is not tailored by age. This likely contributes to high graft failure and posttransplant complications. We present the aims, design, and methods of the Pediatric Outcomes in Transplant: PersOnaliSing Immunosuppression To ImproVe Efficacy Study aimed at personalizing posttransplant immunosuppression in children and young adults.

Methods

In this prospective observational cohort study, we recruited pediatric and young adult solid organ transplant, pediatric allogeneic hematopoietic stem cell transplant recipients, and matched living and deceased organ donors from 14 transplant centers across Canada. Clinical data, questionnaires, biospecimens, and pharmacy records were collected at serial time points: (1) to identify genetic and host immune factors that influence immunosuppression dose requirements across different ages and transplant types, (2) to identify viral-host interactions that increase susceptibility to Epstein-Barr virus infection, and (3) to define care processes and structures associated with medication adherence in adolescents and young adults.

Results

From 2015 to 2018, 1662 new and prevalent transplant recipients were screened, 1166 were recruited for the various aims, including 370 liver, 445 kidney, 277 heart, 19 lung, 19 multiple, and 36 hematopoietic stem cell transplant transplants. Twelve percent were younger than 2 years, 30% were 2 to 10 years, 42% were 10 to 18 years, and 16% were 18 to 24 years at enrollment. Nine hundred thirty-one consented to participation in aims 1 and 2 (90% consent rate), 287 to aim 3 (82% consent rate). Biospecimens collected included 898 for DNA, 276 for immunoassays, and 717 for biomarker studies. Seventy percent participants have completed follow-up; 30% are pending study completion.

Conclusions

The design of this national multicenter cross-organ network helped maximize recruitment of a large patient cohort for studying age and organ-related differences in immunosuppression needs that would not otherwise be feasible. Leveraging the unique clinical, biological, environmental, and behavioral characteristics of this cohort will help develop precision medicine strategies for individualizing posttransplant immunosuppression.

A single-center experience of post-transplant lymphoproliferative disorder (PTLD) cases after pediatric liver transplantation: Incidence, outcomes, and association with food allergy

BACKGROUND/AIMS

We evaluated our 16-year single-center experience of pediatric post-transplant lymphoproliferative disorder (PTLD) cases who underwent liver transplantation between 2001 and 2017.

MATERIALS AND METHODS

Of the 236 pediatric patients who underwent liver transplantation between 2001 and 2017, the clinical and laboratory data of eight patients diagnosed with PTLD were reviewed. The pre-transplant Epstein-Barr virus (EBV) status of 172 patients was also recorded.

RESULTS

The total incidence of PTLD was 3.4%. The incidence of PTLD was 10% in pre-transplant EBV immunoglobulin G (IgG)-seronegative patients and 0.8% in pre-transplant EBV IgG-seropositive patients. The mean age of the patients at liver transplantation was 2.71±3.21 years, and four patients were aged below 1 year at the time of transplantation. PTLD was diagnosed at 21.81±18.1 months after transplantation. The primary site of involvement was variable among patients: peripheral and mediastinal lymph nodes, stomach and intestine, transplanted graft, bone marrow, and nasopharynx. The eosinophil count varied greatly among patients, with a mean value of 524.62±679/mm3. Three patients had a food allergy and were administered an elimination diet at the time of PTLD diagnosis. Six patients had PTLD of B-cell origin. One patient died due to neutropenic sepsis during chemotherapy, whereas seven patients were followed up in full remission for 7.75±4 years.

CONCLUSION

PTLD is a life-threatening complication of solid-organ transplantation with a heterogeneous clinical spectrum. Food allergy had a close association with PTLD. A close follow-up of patients with risk factors and an early diagnosis with appropriate treatment may lead to a better outcome.

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.