Risk-adapted Treatment for Severe B-Lineage Posttransplant Lymphoproliferative Disease After Solid Organ Transplantation in Children

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.

Treatment of Monomorphic Posttransplant Lymphoproliferative Disorder in Pediatric Solid Organ Transplant: A Multicenter Review

Posttransplant lymphoproliferative disorder (PTLD) is the most common posttransplant malignancy in children. We reviewed data from 3 Canadian pediatric centers to determine patient characteristics, treatment approaches, and outcomes for children with monomorphic PTLD. There were 55 eligible children diagnosed between January 2001 to December 2021. Forty-eight patients (87.2%) had B-cell PTLD: Burkitt lymphoma (n = 25; 45.4%) and diffuse large B-cell lymphoma (n = 23; 41.2%), the remainder had natural killer (NK)/T-cell lymphoma (n = 5; 9.1%), Hodgkin lymphoma (n = 1;1.8%), or other (n = 1;1.8%). Thirty-nine (82.1%) patients with B-cell PTLD were treated with rituximab and chemotherapy with or without a reduction in immunosuppression (reduced immune suppression). The chemotherapy used was primarily one of 2 regimens: Mature Lymphoma B-96 protocol in 22 patients (56.4%) and low-dose cyclophosphamide with prednisone in 14 patients (35%). Most patients with T/NK-cell lymphoma were treated with reduced immune suppression + chemotherapy (n = 4; 80%). For all patients with monomorphic PTLD, the projected 3-year event-free survival/3-year overall survival was 62% and 77%, respectively. Of the patients, 100% with T/NK-cell PTLD 100% progressed or relapsed and, subsequently, died of disease. For patients with B-cell PTLD, there was no significant difference in outcome between the two main chemotherapy regimens employed.

Epstein-Barr virus-associated risk factors for post-transplant lymphoproliferative disease in pediatric liver transplant recipients

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) are the most common de novo malignancies after liver transplantation (LT) in children. The aim of our study was to assess the role of pre-LT EBV status and post-LT EBV viral load as risk factors for developing PTLD in a cohort of pediatric LT recipients.

METHODS

Data of all children who underwent LT between January 2002 and December 2019 were collected. Two cohorts were built EBV pre-LT primary infected cohort and EBV post-LT primary infected cohort. Moreover, using the maximal EBV viral load, a ROC curve was constructed to find a cutoff point for the diagnosis of PTLD.

RESULTS

Among the 251 patients included in the study, fifteen PTLD episodes in 14 LT recipients were detected (2 plasmacytic hyperplasia, 10 polymorphic PTLD, 2 monomorphic PTLD, and 1 Classical-Hodgkin's lymphoma). Patients of the EBV post-LT primary infected cohort were 17.1 times more likely to develop a PTLD than patients of the EBV pre-LT primary infected cohort (2.2-133.5). The EBV viral load value to predict PTLD was set at 211 000 UI/mL (93.3% sensitivity and 77.1% specificity; AUC 93.8%; IC 0.89-0.98). In EBV post-LT primary infected cohort, patients with a viral load above 211 000 were 30 times more likely to develop PTLD than patients with a viral load below this value (OR 29.8; 3.7-241.1; p < 0.001).

CONCLUSIONS

The combination of pretransplant EBV serological status with EBV post-transplant viral load could be a powerful tool to stratify the risk of PTLD in pediatric LT patients.

Seropositivity for cytomegalovirus and PCR-EBV monitoring: Protective factors for posttransplant lymphoproliferative disorder in pediatric liver transplant

BACKGROUND

PTLD is a clinical condition with high mortality. Monitoring EBV replication can be a useful tool to avoid the development of PTLD.

MATERIALS AND METHODS

This was a retrospective analysis of 428 pediatric patients who underwent liver transplantation between 1989 and 2016. The patients were divided into 2 groups (transplanted before 2006, when PCR-EBV was not monitored, and after 2006, when PCR-EBV monitoring was started). Patients with continuous PCR measurements for EBV were evaluated for the impact of a reduction in immunosuppression or a change in immunosuppressants on the number of viral copies. A logistic regression model was applied to evaluate factors related to PTLD.

RESULTS

The prevalence of PTLD was 4.2%. After monitoring patients with PCR for EBV levels, a predominance of the most severe, monomorphic form of lymphoproliferative disorder was observed (p = .009). The PTLD mortality was 5%. There was a change in the PCR level after tacrolimus reduction (p = .002) and after tacrolimus exchange for mTOR (p = .008). The number of EBV copies was significantly higher (p = .029) in patients who developed PTLD. In the multiple regression model, seropositivity for CMV was an independent protective factor for lymphoproliferative disorder (OR=0.09; 95% CI 0.02-0.42), reducing the chance of having PTLD adjusted by serology for EBV by 91%.

CONCLUSIONS

Monitoring the EBV viral load by PCR seems to prevent the emergence of milder forms of lymphoproliferative disorder. Pretransplant seropositivity for CMV is a protective factor for PTLD.

Current Practices on Diagnosis, Prevention and Treatment of Post-Transplant Lymphoproliferative Disorder in Pediatric Patients after Solid Organ Transplantation: Results of ERN TransplantChild Healthcare Working Group Survey

(1) Background: Post-transplant lymphoproliferative disease (PTLD) is a significant complication of solid organ transplantation (SOT). However, there is lack of consensus in PTLD management. Our aim was to establish a present benchmark for comparison between international centers and between various organ transplant systems and modalities; (2) Methods: A cross-sectional questionnaire of relevant PTLD practices in pediatric transplantation was sent to multidisciplinary teams from 17 European center members of ERN TransplantChild to evaluate the centers’ approach strategies for diagnosis and treatment and how current practices impact a cross-sectional series of PTLD cases; (3) Results: A total of 34 SOT programs from 13 European centers participated. The decision to start preemptive treatment and its guidance was based on both EBV viremia monitoring plus additional laboratory methods and clinical assessment (61%). Among treatment modalities the most common initial practice at diagnosis was to reduce the immunosuppression (61%). A total of 126 PTLD cases were reported during the period 2012–2016. According to their histopathological classification, monomorphic lesions were the most frequent (46%). Graft rejection after PTLD remission was 33%. Of the total cases diagnosed with PTLD, 88% survived; (4) Conclusions: There is still no consensus on prevention and treatment of PTLD, which implies the need to generate evidence. This might successively allow the development of clinical guidelines.

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.

Effectiveness of Preemptive Therapy for Cytomegalovirus Disease in Pediatric Liver Transplantation

BACKGROUND

Most pediatric liver transplantation (LT) centers administer long courses of prophylaxis against cytomegalovirus (CMV) without evidence of benefit and with significant drug exposure and costs. We aimed at evaluating overall outcomes, direct and putative indirect effects of CMV, possible impact of viremia and risk factors for CMV infection in pediatric LT recipients managed with ganciclovir-based preemptive therapy (PET).

METHODS

The records of all the children who underwent LT between 2008 and 2014 were retrospectively analyzed.

RESULTS

One hundred children were included. Three children had CMV disease; no CMV-related death or graft loss was recorded. The only identified risk factor for CMV infection was the donor/recipient serostatus (odds ratio, 17.23; 95% confidence interval, 1.88-157.87; P = 0.012), while viremia per se did not worsen LT outcomes, such as the incidence of acute rejection, Epstein-Barr virus infection, sepsis, biliary and vascular complications, nor graft dysfunction/loss or death at 3 and 5 years after LT. When compared with a historical cohort of children receiving ganciclovir prophylaxis, PET did not differ from prophylaxis for any of the selected outcomes, but was rather associated with lower antiviral drug exposure (6.4 ± 13 days vs 38.6 ± 14 days, P < 0.0001) and cost per patient (2.2 ± 3.9 k&OV0556; vs 6.6 ± 8.2 k&OV0556;, P = 0.001).

CONCLUSIONS

PET is effective in controlling CMV in children receiving LT, with lower costs and lower exposure to antivirals.

Pathophysiology of Pediatric Multiple Organ Dysfunction Syndrome

OBJECTIVE

To describe the pathophysiology associated with multiple organ dysfunction syndrome in children.

DATA SOURCES

Literature review, research data, and expert opinion.

STUDY SELECTION

Not applicable.

DATA EXTRACTION

Moderated by an experienced expert from the field, pathophysiologic processes associated with multiple organ dysfunction syndrome in children were described, discussed, and debated with a focus on identifying knowledge gaps and research priorities.

DATA SYNTHESIS

Summary of presentations and discussion supported and supplemented by relevant literature.

CONCLUSIONS

Experiment modeling suggests that persistent macrophage activation may be a pathophysiologic basis for multiple organ dysfunction syndrome. Children with multiple organ dysfunction syndrome have 1) reduced cytochrome P450 metabolism inversely proportional to inflammation; 2) increased circulating damage-associated molecular pattern molecules from injured tissues; 3) increased circulating pathogen-associated molecular pattern molecules from infection or endogenous microbiome; and 4) cytokine-driven epithelial, endothelial, mitochondrial, and immune cell dysfunction. Cytochrome P450s metabolize endogenous compounds and xenobiotics, many of which ameliorate inflammation, whereas damage-associated molecular pattern molecules and pathogen-associated molecular pattern molecules alone and together amplify the cytokine production leading to the inflammatory multiple organ dysfunction syndrome response. Genetic and environmental factors can impede inflammation resolution in children with a spectrum of multiple organ dysfunction syndrome pathobiology phenotypes. Thrombocytopenia-associated multiple organ dysfunction syndrome patients have extensive endothelial activation and thrombotic microangiopathy with associated oligogenic deficiencies in inhibitory complement and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13. Sequential multiple organ dysfunction syndrome patients have soluble Fas ligand-Fas-mediated hepatic failure with associated oligogenic deficiencies in perforin and granzyme signaling. Immunoparalysis-associated multiple organ dysfunction syndrome patients have impaired ability to resolve infection and have associated environmental causes of lymphocyte apoptosis. These inflammation phenotypes can lead to macrophage activation syndrome. Resolution of multiple organ dysfunction syndrome requires elimination of the source of inflammation. Full recovery of organ functions is noted 6-18 weeks later when epithelial, endothelial, mitochondrial, and immune cell regeneration and reprogramming is completed.