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

Epstein-Barr virus-specific T-cell response in pediatric liver transplant recipients: a cross-sectional study by multiparametric flow cytometry

Background

Epstein-Barr virus (EBV) specific T-cell response measurement can help adjust immunosuppression in transplant patients with persistent infections. We aim to define T-cell responses against EBV in a cohort of pediatric liver-transplant patients.

Methods

Thirty-eight immunosuppressed pediatric liver-transplant patients (IP) and 25 EBV-seropositive healthy-adult controls (HC) were included in our cross-sectional study. Based on their EBV serological (S) and viral load (VL) status, patients were categorized into IP-SNEG, IP-SPOSVLNEG and IP-SPOSVLPOS groups. T-cell response was assessed at two timepoints by stimulating cells with EBV peptides (PepTivator®) and performing intracellular-cytokine and activation-induced marker staining. Background subtraction was used to determine EBV-specific T-lymphocyte frequency.

Results

Polyfunctional CD8+ T cells indicated previous EBV contact (IP-SNEG 0.00% vs IP-SPOS 0.04% and HC 0.02%; p=0.001 and p=0.01, respectively). Polyfunctional CD8+CD107a+IFNɣ+IL2-TNFα- profile was increased in serology-positive (IP-SNEG 0.01% vs IP-SPOS 0.13% and HC 0.03%; p=0.01 and p=0.50, respectively) and viral-load positive (IP-SPOSVLPOS 0.43% vs IP-SPOSVLNEG 0.07% and HC 0.03%; p=0.03 and p=0.001, respectively) patients. Central-memory cells were increased among serology-positive adults (IP-SNEG 0.00% vs IP-SPOS 0.13% and HC 4.33%; p=0.58 and p=0.002, respectively). At the second timepoint, IP-SNEG patients remained negative (first visit 0.01% vs second visit 0.00%, p=0.44). On the other hand, IP-SPOSVLPOS patients had cleared viral loads and, subsequently, decreased polyfunctional CD8+CD107a+IFNɣ+IL2-TNFα- cells (first visit 0.43% vs second visit 0.10%, p=0.81).

Conclusion

Polyfunctional CD8+ EBV-specific T-cell response allows detecting EBV previous contact in liver-transplant children. %CD8+CD107a+IFNɣ+IL2-TNFα- is increased in patients with positive viral loads. Central memory CD4+ T-cell population more effectively determines prior EBV-exposure in adults.

Posttransplant Lymphoproliferative Disorder in Pediatric Solid-Organ Transplant Recipients: A 7-Year Single-Center Analysis

OBJECTIVES

Posttransplant lymphoproliferative disorder is a consequential complication following solid-organ transplant, particularly associated with the Epstein-Barr virus. We studied a single center's cases of pediatric posttransplant lymphoproliferative disorder for a 7-year period and focused on incidence rates, anatomic sites involved, and correlation with clinical outcomes. We explored clinical features and treatment outcomes in patients with pediatric posttransplant lymphoproliferative disorder, with emphasis on patient survival and associated clinical ramifications.

MATERIALS AND METHODS

This was a retrospective analysis of medical records from pediatric solid-organ transplant recipients (liver or kidney) at Baskent University Ankara Hospital Organ Transplantation Center between January 1, 2017, and January 1, 2024, approved by the Institutional Review Board (KA24/63). We identified cases based on pathology-confirmed persistent lymphadenopathy or tumorous lesions. Patient categorization distinguished between malignant and benign groups. Early posttransplant lymphoproliferative disorder was defined within the initial year after transplant. Epstein?Barr virus association was determined through in situ hybridization, and patient characteristics were reviewed comprehensively.

RESULTS

In 7 years, 10 pediatric patients (9 liver transplants, 1 kidney transplant) were diagnosed with posttransplant lymphoproliferative disorder, with an incidence of 8.7% for pediatric liver transplants. Mean age at diagnosis was 46.4 months, and mean time from transplant to diagnosis was 21.2 months. The most common complaints at diagnosis included fever, lymphadenopathy, hepatosplenomegaly, dyspnea, and diarrhea. Treatment modalities included rituximab, immunosuppression reduction, intravenous immunoglobulin therapy, and chemotherapy (NHL Berlin-Frankfurt-Münster 90 protocols). All patients achieved remission (mean follow-up, 22.9 mo).

CONCLUSIONS

Early diagnosis of posttransplant lymphoproliferative disorder is important, and rituximab with immunosuppression reduction is effective to achieve complete remission, particularly in early polymorphic cases. Despite challenges, all patients achieved remission, signaling improved outcomes in pediatric posttransplant lymphoproliferative disorder. Active monitoring of Epstein?Barr virus infection may further reduce posttransplant lymphoproliferative disorder complications in pediatric solid-organ transplant; hence, early diagnosis is crucial.

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.

A pediatric case series of catastrophic gastrointestinal complications of posttransplant lymphoproliferative disease with increasing incidence, high association with coronavirus disease 2019, higher mortality, and a plea for early endoscopy to prevent late fatal outcome

BACKGROUND

Posttransplant lymphoproliferative disorder is one of the most severe complications after transplantation, caused by uncontrolled proliferation of Epstein-Barr virus-positive B-cells in the setting of chronic immunosuppression. As one of the biggest transplant centers worldwide, we observed a potential increase in the number of patients with posttransplant lymphoproliferative disorder presenting with gastrointestinal symptoms in 1 year, during the coronavirus disease 2019 pandemic. There is limited information about dysregulation of the immune system following coronavirus disease 2019 infection, which may lead to Epstein-Barr virus reactivation in Epstein-Barr virus-positive B-cells and development of posttransplant lymphoproliferative disorder. Furthermore, there is no consensus in literature on a modality that can help in early diagnosis of posttransplant lymphoproliferative disorder with nonspecific gastrointestinal presentations before late and fatal complications occur.

CASE PRESENTATION

Our case series includes five Iranian (Persian) patients, three female (2, 2.5, and 5 years old) and two male (2 and 2.5 years old), who developed gastrointestinal posttransplant lymphoproliferative disorder after liver transplantation. All of our patients were on a similar immunosuppressant regimen and had similar Epstein-Barr virus serologic status (seronegative at time of transplantation but seropositive at time of posttransplant lymphoproliferative disorder diagnosis). Four patients had either a positive coronavirus disease 2019 polymerase chain reaction test or exposure within the family. Although all of our patients presented with nonspecific gastrointestinal symptoms, four patients developed late posttransplant lymphoproliferative disorder complications such as bowel perforation and obstruction. All five patients with gastrointestinal posttransplant lymphoproliferative disorder received chemotherapy, but only two survived and currently are continuing the therapy. In one of the surviving patients, prompt endoscopic investigation resulted in early diagnosis of posttransplant lymphoproliferative disorder and a better outcome.

CONCLUSION

Since 80% of our patients had exposure to coronavirus, a potential relationship might be suggested between the two. Furthermore, as we witnessed in one case, urgent endoscopic investigation in immunocompromised patients presenting with gastrointestinal symptoms can improve the clinical outcomes and therefore should be considered for early diagnosis of posttransplant lymphoproliferative disorder.

Prognostic factors and scoring systems associated with outcome in pediatric acute liver failure

BACKGROUND

Pediatric acute liver failure (PALF) is an uncommon, devastating illness with significant mortality. Liver transplantation remains the mainstay of treatment for irreversible PALF. The purpose of this study was to determine the etiology and prognostic factors associated with outcome of PALF in South Africa and to evaluate prognostic scoring systems used.

METHODS

Records of 45 pediatric patients younger than 16 years of age who presented with PALF from 1 January 2015 till 31 October 2020 were analysed. Patients were divided into two groups with one group consisting of patients with spontaneous recovery of the liver with supportive treatment (6/45:13.3%) and the second group consisting of patients with poor outcomes who demised (19/45: 42%) or underwent liver transplantation (20/45: 44%).

RESULTS

The median age of presentation was 3.3 years (IQR 1.8-6.9) with the 1-5 years age group constituting majority of patients (55.6%). Median time to follow up was 6.1 months (IQR 0.2-28.8). Higher liver injury unit scores were observed in patients who had poorer outcomes (P = 0.008) with a threshold of greater than 246 having a sensitivity of 84% and specificity of 83% (P < 0.001). Higher peak PELD/MELD (P = 0.006) and admission UKELD (P = 0.002) scores, were found in patients with poorer outcomes. Kings College Hospital criteria (KCHC) was useful in predicting which patients would die without liver transplantation (P = 0.002). Liver transplantation was performed in 20/45 (44%) patients with a post transplantation 1 year patient and graft survival of 80%.

CONCLUSION

Although, survival of PALF patients was lower than high and other low-middle income countries, outcomes post transplantation were good. Our study demonstrates the utility of dynamic scoring systems in PALF patients, it underscores the need for early referral and clinical monitoring in a tertiary center once the criteria for PALF have been met.

Mycophenolate mofetil use is associated with reduced incidence of food allergy in liver transplanted children

OBJECTIVES

The incidence of food allergy in children following liver transplantation is high and the pathogenesis is still not known. We aimed to identify risk factors for development of food allergies in liver transplant children.

METHODS

107 children and adolescents who underwent liver transplantation from 1999 to 2019 were included. Data were retrospectively collected from medical records included total and specific IgE, eosinophil cationic protein and eosinophil count 12 months after transplantation and at yearly follow up (median follow-up).

RESULTS

24/107 (22%) patients reported clinical food reactions. Median time from transplantation to debut of food allergy was 1.6 (IQR 0.6-3.3) years. Mycophenolate mofetil (MMF) was discontinued in 24/78 patients (31%) due to side effects. Children treated with MMF in addition to tacrolimus one year after transplantation reported less food allergy (12.5% vs. 37.8%, p=0.003) and sensitization to food allergens one year after transplantation (8.9% vs. 17.8%, p=0.02) than those not receiving MMF. Tacrolimus trough levels did not differ between the patients treated with MMF and those who were not. Treatment with MMF two years after transplantation was associated with less food allergy (p=0.001) and food sensitization (p=0.002), also when adjusted for age at transplantation (p=0.006 and p=0.03, respectively) or for use of basilixmab (p=0.015 and p=0.018, respectively). Basiliximab was also associated with less food allergy.

CONCLUSIONS

Use of MMF one and two years after transplantation was associated with less food allergy and sensitization against food allergens. The effect of MMF was not due to reduced trough levels of of tacrolimus. An infographic is available for this article at: https://links.lww.com/MPG/C821.

Nondestructive versus advanced post-transplant lymphoproliferative disorder in a single-center pediatric kidney transplant population

BACKGROUND

Pediatric kidney transplant recipients are at risk for the development of post-transplant lymphoproliferative disorders (PTLD), a group of potentially devastating diseases that present on a spectrum of severity ranging from nondestructive PTLD to more histologically destructive lesions. Currently, there is inadequate evidence to guide evaluation and management of nondestructive PTLD.

METHODS

This is a single-center case series of pediatric kidney transplant recipients between January 1, 2008 and December 31, 2019, who were diagnosed with PTLD. The aim was to describe clinical characteristics, presentation, and management of nondestructive versus advanced PTLD.

RESULTS

Eighteen patients were diagnosed with nondestructive PTLD and seven with more advanced PTLD histopathology. The majority (66.7%) of nondestructive PTLD patients (n = 16) presented with tonsillar hypertrophy and/or snoring and were managed conservatively, with minimal reduction in tacrolimus dose and no further evaluation. No patient progressed to more advanced PTLD. Advanced PTLD patients (n = 7) were more likely to present with fever, elevated creatinine, a new mass of gastrointestinal symptoms. They received workup with imaging and oncology consultation, and were managed with chemotherapy.

CONCLUSIONS

Patients with nondestructive PTLD often present with symptoms of sleep-disordered breathing and can be managed conservatively with excellent clinical outcomes. More study is needed to guide care of this under-researched population.

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.

Post-transplant eosinophilic gastrointestinal disorders and lymphoproliferative disorder in pediatric liver transplant recipients on tacrolimus

AIM

To examine and characterize post-transplant eosinophilic gastrointestinal disorders (PTEGID) and post-transplant lymphoproliferative disorder (PTLD) in pediatric liver transplant recipients.

METHODS

This is a single center retrospective study of all liver transplant recipients aged 0-18 years from 1999 to 2019 who received tacrolimus as their primary immunosuppressant. Demographic data and clinical/laboratory data including PTEGID, PTLD, liver transplant types, Epstein-Barr virus status, and blood eosinophil count were reviewed. Analysis was done with logistic regression and Mann-Whitney U test.

RESULTS

Ninety-eight pediatric liver transplant recipients were included with median age at transplantation of 3.3 years (IQR: 1.1-9.3). The major indication for transplantation was biliary atresia, 51 (52%) cases. Eight (8%) children had PTLD and 14 (14%) had PTEGID. Receiving liver transplantation at an age of ≤1 year was associated with developing PTEGID (OR = 11.9, 95% CI = 3.5-45.6, p < 0.001). Additionally, eosinophilic count of ≥500/μL was associated with having PTLD (OR = 10.7, 95% CI = 1.8-206.0, p = 0.030) as well as having at least one liver rejection (OR = 2.8, 95% CI = 1.2-7.0, p = 0.024). The frequency of food-induced anaphylaxis significantly increased post-transplantation (p = 0.023).

CONCLUSIONS

PTEGID and PTLD are common in this cohort and are associated with certain risk factors that help screen children to improve recipient survival. Further studies are needed to evaluate the clinical benefits of these findings.

Post-transplant lymphoproliferative disorder after paediatric liver transplantation

OBJECTIVE

The purpose of this study was to analyse the clinical and pathological characteristics, treatments and outcomes of post-transplant lymphoproliferative disorder (PTLD) in paediatric liver transplant recipients.

METHOD

A retrospective analysis of records from nine paediatric liver transplant recipients with PTLD who were treated at our Liver Transplant Center over the period from June 2013 to August 2018.

RESULT

Of these nine patients, seven received liver transplantation in our centre and the remaining two patients at other hospitals. The overall incidence of PTLD in paediatric liver transplant recipients in our centre was 1.4% (7/485). The median onset of PTLD after liver transplantation was 11 months. Three cases were classified as infectious mononucleosis PTLD, one case was plasmacytic hyperplasia PTLD, one case was polymorphic PTLD and two cases were Burkitt lymphoma. One case showed diffuse large B-cell lymphoma and one was classical Hodgkin lymphoma-like PTLD. These patients presented with different clinical manifestations including fever, anaemia, diarrhoea, hypoproteinaemia, enlargement of lymph nodes, hepatosplenomegaly, jaundice, bowel obstruction and even intestinal perforation. Nine patients were positive for EBV-DNA in serum. After diagnosis, immunosuppressants were reduced or discontinued in all cases. Eight patients received anti-CD20 monoclonal antibody (Rituximab) therapy, four cases were treated with a combination of chemotherapy (R-CHOP, ABVD, COPP/ABV) and one case was combined with radiotherapy. Two cases received surgical treatment due to bowel obstruction. Eight of these patients achieved a complete remission and remained healthy when assessed at the time of final follow-up. One patient died as a result of PTLD progression.

CONCLUSION

PTLD is one of the most serious and fatal complications after liver transplantation. The definitive diagnosis requires histopathology. Treatment varies and basically includes immunosuppression reduction, anti-CD20 antibody, surgery, radiotherapy and chemotherapy.

Malignant Post-Transplant Lymphoproliferative Disorder of Nasopharynx in Myelodysplastic Disorder

(1) Background: Post-transplant lymphoproliferative disorder (PTLD) is a hematological disease and occurs because of immunosuppression after organ transplantation. Only a few studies have reported PTLD in the nasopharynx. In most cases, PTLD developed after solid organ transplantation, and cases of PTLD after bone marrow transplantation, are uncommon. (2) Case presentation: We report the case of a 40-year-old woman with myelodysplastic disorder who underwent hematopoietic stem cell transplantation (HSCT). After 3 months, she developed low-grade fever, progressive nasal obstruction, and bloody rhinorrhea. Endoscopy revealed a mass completely occupying the nasopharynx. A polymorphic PTLD was diagnosed on the basis of histopathological examination results. Reduction in immunosuppression and low-dose radiotherapy were prescribed for treatment. After a 3-year follow-up, no recurrence of PTLD or myelodysplastic disorder was detected. (3) Conclusions: While nasopharyngeal PTLD is rare, a routine examination of the nasopharynx should be considered in the post-transplant follow-up of patients for early detection and treatment of PTLD.

Impact of EBV infection and immune function assay for lymphoproliferative disorder in pediatric patients after liver transplantation: A single-center experience

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is a lethal complication after pediatric liver transplantation, but information regarding risk factors for the development of PTLD remains unclear. This study was to identify characteristics and risk factors of PTLD.

METHODS

A total of 705 pediatric patients who underwent liver transplantation between January 2017 and October 2018 were studied. Impact of clinical characteristics and Epstein-Barr virus (EBV) infection on the development of PTLD was evaluated. In addition, ImmuKnow assay was adopted in partial patients to analyze the immune status.

RESULTS

Twenty-five (3.5%) patients suffered from PLTD with a median time of 6 months (3-14 months) after transplantation. Extremely high tacrolimus (TAC) level was found in 2 fatal cases at PTLD onset. EBV infection was found in 468 (66.4%) patients. A higher peak EBV DNA loads (>9590 copies/mL) within 3 months was a significant indicator for the onset of PTLD. In addition, the ImmuKnow assay demonstrated that overall immune response was significantly lower in patients with EBV infection and PTLD (P<0.0001). The cumulative incidence of PTLD was also higher in patients with lower ATP value (≤187 ng/mL, P<0.05).

CONCLUSIONS

A careful monitoring of EBV DNA loads and tacrolimus concentration might be supportive in prevention of PTLD in pediatric patients after liver transplantation. In addition, application of the ImmuKnow assay may provide guidance in reducing immunosuppressive agents in treatment of PTLD.

Mesenchymal stem cells prolong the survival of orthotopic liver transplants by regulating the expression of TGF-β1

BACKGROUND/AIMS

Recent studies have shown that transforming growth factor-β1 (TGF-β1) is prominently associated with acute rejection. This study aimed to explore the role of mesenchymal stem cells (MSCs) in the maintenance of the long-term survival of orthotopic liver transplants (OLTs) via the regulation of TGF-β1 in an experimental rat model.

MATERIALS AND METHODS

We used Lewis rats as donors and ACI rats as recipients. Hematoxylin and eosin staining was performed to evaluate histomorphological changes, and Western blot was performed to measure protein expression.

RESULTS

The expression of TGF-β1 in the liver allografts and spleen and protein levels of forkhead box P3 (FoxP3), interleukin-10 (IL-10), and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) were measured using Western blot. The suppressive capacity of CD4+CD25+ regulatory T cells was evaluated using the MTT assay. Cell-mediated immunotoxicity was evaluated using the mixed lymphocyte reaction of CD4+ T cells and cytotoxic T lymphocyte (CTL) assay of CD8+ T cells. The results showed that MSCs prolonged the survival of the OLT mice by regulating the expression of TGF-β1 at different time points. The administration of MSCs promoted a prolonged survival in the ACI recipients (105±6.6 d) compared with the MSC-untreated recipients (16.2±4.0 d). On the postoperative day (POD) 7, the MSC-treated recipients showed a significantly higher expression of TGF-β1, FoxP3, IL-10, and CTLA-4 than the MSC-untreated recipients. However, on POD 100, the MSC-treated recipients showed a lower expression of TGF-β1 and FOxP3 than that on POD 7. Moreover, on POD 7, CD4+CD25+ regulatory T cells extracted from the MSC-treated recipients showed a higher expression of FoxP3, IL-10, CTLA-4, and suppressive capacity. On POD 7, CD4+ T cells from the MSC-treated recipients showed more significantly diminished proliferative functions than the MSC-untreated recipients; further, a reduced allospecific CTL activity of CD8+ T cells was observed in the MSC-treated recipients.

CONCLUSION

MSCs may represent a promising cell therapeutic approach for inducing immunosuppression or transplant tolerance.