CNS or bone marrow involvement as risk factors for poor survival in post-transplantation lymphoproliferative disorders in children after solid organ transplantation

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 disorders following kidney transplantation: A literature review with updates on risk factors, prognostic indices, screening strategies, treatment and analysis of donor type

Post-transplant lymphoproliferative disorders (PTLD) is a devastating complication of kidney transplantation with an insidious presentation and potential to disseminate aggressively. This review delineates the risk factors, prognostic indexes, screening, current management algorithm and promising treatment strategies for PTLD. Kidneys from both extended criteria donors (ECD) and living donors (LD) are being increasingly used to expand the donor pool. This review also delineates whether PTLD outcomes vary based on these donor sources. While Epstein-Barr virus (EBV) is a well-known risk factor for PTLD development, the use of T-cell depleting induction agents has been increasingly implicated in aggressive, monomorphic forms of PTLD. Research regarding maintenance therapy is sparse. The international prognostic index seems to be the most validate prognostic tool. Screening for PTLD is controversial, as annual PET-CT is most sensitive but costly, while targeted monitoring of EBV-seronegative patients was more economically feasible, is recommended by the American Society of Transplantation, but is limited to a subset of the population. Other screening strategies such as using Immunoglobulin/T-cell receptor require further validation. A risk-stratified approach is taken in the treatment of PTLD. The first step is the reduction of immunosuppressants, after which rituximab and chemotherapy may be introduced if unsuccessful. Some novel treatments have also shown potential benefit in studies: brentuximab vedotin, chimeric antigen receptor T-cell therapy and EBV-specific cytotoxic T lymphocytes. Analysis of LD v DD recipients show no significant difference in incidence and mortality of PTLD but did reveal a shortened time to development of PTLD from transplant. Analysis of SCD vs ECD recipients show a higher incidence of PTLD in the ECD group, which might be attributed to longer time on dialysis for these patients, age, and the pro-inflammatory nature of these organs. However, incidence of PTLD overall is still extremely low. Efforts should be focused on optimising recipients instead. Minimising the use of T-cell depleting therapy while encouraging research on the effect of new immunosuppressants on PTLD, screening for EBV status are essential, while enabling shared decision-making during counselling when choosing kidney donor types and individualised risk tailoring are strongly advocated.

Post-Transplant Lymphoproliferative Disorders

Post-transplant lymphoproliferative disorders (PTLDs) are a heterogenous set of unregulated lymphoid cell proliferations after organ or tissue transplant. A majority of cases are associated with the Epstein-Barr virus and higher intensity of pharmacologic immunosuppression. The clinical presentations are numerous. The diagnosis is ideally by histology, except in cases where the tumor is inaccessible to biopsy. While some pre-emptive therapies and treatment strategies are available have reasonable success are available, they do not eliminate the high morbidity and significant mortality after PTLD.

How I treat posttransplant lymphoproliferative disorder

Posttransplant lymphoproliferative disorder (PTLD) is an important and potentially life-threatening complication of solid organ transplant and hematopoietic stem cell transplant (HSCT). Given the heterogeneity of PTLD and the risk of infectious complications in patients with immunosuppression, the treatment of this disease remains challenging. Monomorphic PTLD and lymphoma of B-cell origin account for the majority of cases. Treatment strategies for PTLD consist of response-adapted, risk-stratified methods using immunosuppression reduction, immunotherapy, and/or chemotherapy. With this approach, ∼25% of the patients do not need chemotherapy. Outcomes for patients with high risk or those who do not respond to frontline therapies remain dismal, and novel treatments are needed in this setting. PTLD is associated with Epstein-Barr virus (EBV) infection in 60% to 80% of cases, making EBV-directed therapy an attractive treatment modality. Recently, the introduction of adoptive immunotherapies has become a promising option for refractory cases; hopefully, these treatment strategies can be used as earlier lines of therapy in the future.

Multicenter study of pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorders

BACKGROUND

Pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorder [EBV(-)M-PTLD] comprises approximately 10% of M-PTLD. No large multi-institutional pediatric-specific reports on treatment and outcome are available.

METHODS

A multi-institutional retrospective review of solid organ recipients diagnosed with EBV(-)M-PTLD aged ≤21 years between 2001 and 2020 in 12 centers in the United States and United Kingdom was performed, including demographics, staging, treatment, and outcomes data.

RESULTS

Thirty-six patients were identified with EBV(-)M-PTLD. Twenty-three (63.9%) were male. Median age (range) at transplantation, diagnosis of EBV(-)M-PTLD, and interval from transplant to PTLD were 2.2 years (0.1-17), 14 years (3.0-20), and 8.5 years (0.6-18.3), respectively. Kidney (n = 17 [47.2%]) and heart (n = 13 [36.1%]) were the most commonly transplanted organs. Most were Murphy stage III (n = 25 [69.4%]). Lactate dehydrogenase was elevated in 22/34 (64.7%) and ≥2 times upper limit of normal in 11/34 (32.4%). Pathological diagnoses included diffuse large B-cell lymphoma (n = 31 [86.1%]) and B-non-Hodgkin lymphoma (B-NHL) not otherwise specified (NOS) (n = 5 [13.9%]). Of nine different regimens used, the most common were: pediatric mature B-NHL-specific regimen (n = 13 [36.1%]) and low-dose cyclophosphamide, prednisone, and rituximab (n = 9 [25%]). Median follow-up from diagnosis was 3.0 years (0.3-11.0 years). Three-year event-free survival (EFS) and overall survival (OS) were 64.8% and 79.9%, respectively. Of the seven deaths, six were from progressive disease.

CONCLUSIONS

EFS and OS were comparable to pediatric EBV(+) PTLD, but inferior to mature B-NHL in immunocompetent pediatric patients. The wide range of therapeutic regimens used directs our work toward developing an active multi-institutional registry to design prospective studies.

PLAIN LANGUAGE SUMMARY

Pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorders (EBV(-)M-PTLD) have comparable outcomes to EBV(+) PTLD, but are inferior to diffuse large B-cell lymphoma in immunocompetent pediatric patients. The variety of treatment regimens used highlights the need to develop a pediatric PTLD registry to prospectively evaluate outcomes. The impact of treatment regimen on relapse risk could not be assessed because of small numbers. In the intensive pediatric B-non-Hodgkin lymphoma chemoimmunotherapy group, 11 of 13 patients remain alive in complete remission after 0.6 to 11 years.

Non-Hodgkin lymphoma after pediatric kidney transplantation

Non-Hodgkin lymphoma (NHL) that develops after kidney transplantation belongs to post-transplant lymphoproliferative disorders (PTLD) occurring with an incidence of 2-3%. Most pediatric cases are related to primary infection with Epstein-Barr virus (EBV), able to transform and immortalize B cells and widely proliferate due to the lack of relevant control of cytotoxic T cells in patients receiving post-transplant immunosuppression. NHL may develop as a systemic disease or as a localized lesion. The clinical pattern is variable, from non-symptomatic to fulminating disease. Young age of transplant recipient, seronegative EBV status at transplantation, and EBV mismatch between donor and recipient (D+/R-) are regarded as risk factors. Immunosuppression impacts the development of both early and late NHLs. Specific surveillance protocols, including monitoring of EBV viral load, are used in patients at risk; however, detailed histopathology diagnosis and evaluation of malignancy staging is crucial for therapeutic decisions. Minimizing of immunosuppression is a primary management, followed by the use of rituximab in B-cell NHLs. Specific chemotherapeutic protocols, adjusted to lymphoma classification and staging, are used in advanced NHLs. Radiotherapy and/or surgical removal of malignant lesions is limited to the most severe cases. Outcome is variable, depending on risk factors and timing of diagnosis, however is positive in pediatric patients in terms of graft function and patient survival. Kidney re-transplantation is possible in survivors who lost the primary graft due to chronic rejection, however may be performed after at least 2-3 years of waiting time, careful verification of malignancy-free status, and gaining immunity against EBV.

Post-transplant lymphoproliferative disease after pediatric kidney transplant

Post-transplant lymphoproliferative disease (PTLD) is the most common malignancy complicating solid organ transplantation (SOT) in adults and children. PTLD encompasses a spectrum of histopathologic features and organ involvement, ranging from benign lymphoproliferation and infectious-mononucleosis like presentation to invasive neoplastic processes such as classical Hodgkin lymphoma. The predominant risk factors for PTLD are Epstein-Barr virus (EBV) serostatus at the time of transplant and the intensity of immunosuppression following transplantation; with EBV-negative recipients of EBV-positive donor organs at the highest risk. In children, PTLD commonly presents in the first two years after transplant, with 80% of cases in the first year, and over 90% of cases associated with EBV-positive B-cell proliferation. Though pediatric kidney transplant recipients are at lower risk (1-3%) for PTLD compared to their other SOT counterparts, there is still a significant risk of morbidity, allograft failure, and an estimated 5-year mortality rate of up to 50%. In spite of this, there is no consensus for monitoring of at-risk patients or optimal management strategies for pediatric patients with PTLD. Here we review pathogenesis and risk factors for the development of PTLD, with current practices for prevention, diagnosis, and management of PTLD in pediatric kidney transplant recipients. We also highlight emerging concepts, current research gaps and potential future developments to improve clinical outcomes and longevity in these patients.

Characteristics, management, and outcome of pediatric patients with post-transplant lymphoproliferative disease-A 20 years' experience from Austria

BACKGROUND

Management of pediatric post-transplantation lymphoproliferative disorder (PTLD) after hematopoietic stem cell (HSCT) and solid organ transplantation (SOT) is challenging.

AIM

This study of 34 PTLD patients up to 19-years old diagnosed in Austria from 2000 to 2018 aimed at assessing initial characteristics, therapy, response, and outcome as well as prognostic markers of this rare pediatric disease.

METHODS AND RESULTS

A retrospective data analysis was performed. Types of allografts were kidney (n = 12), liver (n = 7), heart (n = 5), hematopoietic stem cells (n = 4), lungs (n = 2), multi-visceral (n = 2), small intestine (n = 1), and vessels (n = 1). Eighteen/34 were classified as monomorphic PTLD, with DLBCL accounting for 15 cases. Polymorphic disease occurred in nine, and non-destructive lesions in six cases. One patient had a non-classifiable PTLD. Thirteen/34 patients are surviving event-free in first remission (non-destructive, n = 4/6; polymorphic, n = 4/9; monomorphic, n = 6/18). Fourteen/34 patients lacked complete response to first-line therapy, of whom seven died. Four/34 patients relapsed, of whom two died. In 3/34 patients, death occurred as a first event. The 5-year overall and event-free survival rates were 64% ± 9% and 35% ± 9% for the whole cohort. Among all parameters analyzed, only malignant disease as the indication for transplantation had a significantly poor influence on survival.

CONCLUSIONS

This study shows PTLD still to be a major cause of mortality following SOT or HSCT in children. A continued understanding of the molecular biology of the disease shall allow to decrease treatment intensity for lower risk patients and to identify patients who may benefit from newer therapy approaches to improve outcome and decrease morbidity.

Stereotactic Radiotherapy for Recurrent Post-Transplant Primary Central Nervous System Lymphoma

Post-transplant primary central nervous system lymphoma (PCNSL) is a rare complication of solid organ transplantation. The optimal therapy for post-transplant PCNSL is not well established and generally includes reduction of immunosuppression and chemotherapy. Progression after front-line chemotherapy is common, and whole-brain radiotherapy (WBRT) is a standard salvage treatment as there is a concern that localized treatment fields would not prevent out-of-field recurrences. However, WBRT is associated with neurotoxicity and morbidity in these patients with inherently poor prognoses. Here, we report a patient with local recurrence of post-transplant PCNSL who was treated with fractionated stereotactic radiotherapy (SRT). He had no clinical toxicity from treatment and maintained pre-treatment neurocognition and performance status. Local control was achieved for 20 months following SRT, at which point he developed an in-field recurrence. He restarted lymphoma therapy but died one month later from fungal pneumonia. For central nervous system (CNS) lymphoma, further data are needed to optimize tumor control and toxicity outcomes and identify patients in whom localized radiotherapy fields may be beneficial, avoiding the potential toxicity of WBRT.

Complete remission from post-heart transplant lymphoproliferative disorder: A case report

We report a case of Burkitt's lymphoma, post-transplant lymphoproliferative disorder (BL-PTLD) that was treated with intensive chemotherapy. The patient was a 4-year-old boy who underwent heart transplantation at 7 months of age for refractory heart failure due to dilated cardiomyopathy. He was admitted to our hospital with a chief complaint of abdominal pain associated with an abdominal mass. Computed tomography was notable for a bulky mass arising from the terminal ileum. Fluorodeoxyglucose-positron emission tomography revealed multiple lesions in brain, bone, and lymph nodes. He was diagnosed with BL-PTLD stage III by pathological and clinical scoring. He was Epstein-Barr virus (EBV)-seronegative with a low EBV viral DNA load. No EBV-encoded small RNAs were in his intra-abdominal lymph nodes by in situ hybridization. On cytogenetic examination, the intra-abdominal lymph nodes revealed both a MYC rearrangement and a t(8;14)(q24;32), t(16;19)(q24;q13.1) translocation. Administration of tacrolimus and mycophenolate mofetil was discontinued; immunosuppression was maintained with everolimus. Intensive chemotherapy based on the modified LMB 96 protocol for BL was initiated, resulting in complete remission achieved. During the intensive chemotherapy and immunosuppressive switching period, cardiac dysfunction and allograft rejection had not been shown. The patient has remained well for two years after the treatment with no evidence of relapse. <Learning objective: Post-transplant lymphoproliferative disorder (PTLD) is a life-threatening complication that can develop after heart transplantation and result in significant morbidity and mortality. In the case presented here, intensive chemotherapy and modified immunosuppressive therapy are among the most effective treatments for PTLD patients with an otherwise poor prognosis. Maintaining a fine balance between management of the PTLD and preventing allograft rejection is critically important.>.

Epstein-Barr virus-associated post-transplant lymphoproliferative disorders: beyond chemotherapy treatment

Post-transplant lymphoproliferative disorder (PTLD) is a rare but life-threatening complication of both allogeneic solid organ (SOT) and hematopoietic cell transplantation (HCT). The histology of PTLD ranges from benign polyclonal lymphoproliferation to a lesion indistinguishable from classic monoclonal lymphoma. Most commonly, PTLDs are Epstein-Barr virus (EBV) positive and result from loss of immune surveillance over EBV. Treatment for PTLD differs from the treatment for typical non-Hodgkin lymphoma because prognostic factors are different, resistance to treatment is unique, and there are specific concerns for organ toxicity. While recipients of HCT have a limited time during which they are at risk for this complication, recipients of SOT have a lifelong requirement for immunosuppression, so approaches that limit compromising or help restore immune surveillance are of high interest. Furthermore, while EBV-positive and EBV-negative PTLDs are not intrinsically resistant to chemotherapy, the poor tolerance of chemotherapy in the post-transplant setting makes it essential to minimize potential treatment-related toxicities and explore alternative treatment algorithms. Therefore, reduced-toxicity approaches such as single-agent CD20 monoclonal antibodies or bortezomib, reduced dosing of standard chemotherapeutic agents, and non-chemotherapy-based approaches such as cytotoxic T cells have all been explored. Here, we review the chemotherapy and non-chemotherapy treatment landscape for PTLD.

Primary post-transplant lymphoproliferative disorder of the central nervous system: characteristics, management and outcome in 25 paediatric patients

Primary central nervous system (CNS) post-transplant lymphoproliferative disorder (PTLD) in childhood is rare. Twenty-five patients were retrieved from nine European Intergroup for Childhood Non-Hodgkin's Lymphoma and/or international Berlin-Frankfurt-Münster Study Group members. Types of allografts included kidney (n = 11), liver (n = 4), heart (n = 5), bowel (n = 1) and haematopoietic stem cells (n = 4). Eighteen were male, 16 ≥ 10 years old, 21 had monomorphic disease and 24 solid intracranial tumour masses. Four-year event-free and overall survival rates were 50% ± 10% and 74% ± 9% respectively. This report represents the largest paediatric series of CNS PTLD reported to date, showing favourable survival odds following systemic and intrathecal chemotherapy and rituximab administration.

Facial Paralysis From Post-transplant Lymphoproliferative Disorder

OBJECTIVE

We report a case of facial paresis and profound hearing loss from post-transplant lymphoproliferative disorder (PTLD) in a pediatric patient with neuroblastoma.

PATIENT

Three-year-old boy with rapidly progressive right facial paresis and sensorineural hearing loss. High-risk neuroblastoma had been diagnosed 1 year earlier, treated with chemotherapy and resection of the adrenal primary tumor. Two months after two autologous hematopoietic stem cell transplantations (HSCT), the patient developed facial paralysis. Magnetic resonance imaging (MRI) showed bilateral progressive internal auditory canal (IAC) enhancing lesions with a mass lesion on the right and wispy enhancement on the left and enhancement within the right cochlea. Lumbar puncture (LP) was positive for Epstein-Barr virus (EBV) making the diagnosis of PTLD most probable. Biopsy of the right IAC lesion was deferred because of potential procedural risks including intradural spread of tumor or fungus. The patient was treated with anti-fungal therapy and systemic rituximab without improvement. Subsequent intrathecal rituximab resulted in improvement of lesions on MRI and clearance of EBV from the cerebrospinal fluid (CSF).

INTERVENTIONS

Mastoidectomy for biopsies from the mastoid and middle ear. Intrathecal treatment with rituximab.

MAIN OUTCOME MEASURES

Imaging assessment of IAC lesion, CSF EBV titers, facial nerve function.

RESULTS

Gradual resolution of IAC mass lesions, remission of PTLD, and facial improvement from House-Brackmann score of 4 to 3.

CONCLUSIONS

PTLD causing facial paresis after autologous HSCT has not been previously reported and may be considered in the differential diagnosis of lesions causing facial paresis in patients who have received a stem cell or solid organ transplant.

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.

Prognostic superiority of International Prognostic Index over [18F]FDG PET/CT volumetric parameters in post-transplant lymphoproliferative disorder

Background

Post-transplant lymphoproliferative disorders (PTLDs) are a spectrum of hematological malignancies occurring after solid organ and hematopoietic stem cell transplantation. [¹⁸F]FDG PET/CT is routinely performed at PTLD diagnosis, allowing for both staging of the disease and quantification of volumetric parameters, such as whole-body metabolic tumor volume (MTV) and total lesion glycolysis (TLG). In this retrospective study, we aimed to determine the prognostic value of MTV and TLG in PTLD patients, together with other variables of interest, such as the International Prognostic Index (IPI), organ transplant type, EBV tumor status, time after transplant, albumin levels and PTLD morphology.

Results

A total of 88 patients were included. The 1-, 3-, 5- year overall survival rates were 67%, 58% and 43% respectively. Multivariable analysis indicated that a high IPI (HR: 1.56, 95% CI: 1.13–2.16) and an EBV-negative tumor (HR: 2.71, 95% CI: 1.38–5.32) were associated with poor overall survival. Patients with a kidney transplant had a longer overall survival than any other organ recipients (HR: 0.38 95% CI: 0.16–0.89). IPI was found to be the best predicting parameter of overall survival in our cohort. Whole-body MTV, TLG, time after transplant, hypoalbuminemia and PTLD morphology were not associated with overall survival.

Conclusion

[¹⁸F]FDG PET/CT whole-body volumetric quantitative parameters were not predictive of overall survival in PTLD. In our cohort, high IPI and an EBV-negative tumor were found to predictors of worse overall survival while kidney transplant patients had a longer overall survival compared to other organ transplant recipients

Reappraisal of the prognostic value of Epstein-Barr virus status in monomorphic post-transplantation lymphoproliferative disorders-diffuse large B-cell lymphoma

The role of the Epstein-Barr virus (EBV) status in the blood for predicting survival in post-transplantation lymphoproliferative disorders-diffuse large B-cell lymphoma (PTLD-DLBCL) is unknown. We evaluated the prognostic values of pre-treatment EBV-encoded small RNA (EBER) detected with in situ hybridization in tissues and EBV DNA in the whole blood (WB) and plasma in 58 patients with monomorphic PTLD-DLBCL after solid organ transplantation. There were no significant differences in the rates of overall response, complete response, and survival according to EBER EBV and WB EBV status. In contrast, patients with positive plasma EBV DNA had significantly lower rates of overall response (60.0% vs. 94.4%, P = 0.043) and complete response (40.0% vs. 88.9%, P = 0.019) as well as worse progression-free survival (PFS) (P = 0.035) and overall survival (OS) (P = 0.039) compared with patients with negative plasma EBV DNA. In multivariate analysis, plasma EBV DNA positivity was a significantly unfavorable prognostic factor for PFS [hazard ratio (HR) 4.92, 95% confidence interval (CI) 1.22-19.86, P = 0.025] and OS (HR 4.48, 95% CI 1.14-17.63, P = 0.032). Despite small number of 6 patients with plasma EBV positivity, plasma EBV DNA positivity might be more prognostic for survival than EBER or WB EBV DNA positivity in patients with monomorphic PTLD-DLBCL.

Trisomy 3, a sole recurrent cytogenetic abnormality in pediatric polymorphic post-transplant lymphoproliferative disorder (PTLD)

Trisomy 3 has been previously reported in association with T-cell lymphomas and less commonly in different types of non-Hodgkin B-cell lymphomas. Trisomy 3 has also been reported in two cases of pediatric post-transplant lymphoproliferative disorder (PTLD). We present comprehensive clinicopathologic review of two pediatric patients with cardiac and liver/intestinal allografts that developed polymorphic PTLD characterized by trisomy 3. Both patients had Epstein-Barr virus (EBV) viremia and EBV was positive in tissue by EBER in situ hybridization. Using karyotype analysis and fluorescence in situ hybridization, we identified trisomy 3 in both patients. Both patients responded to treatment and are now free of the PTLD. Trisomy 3, an uncommon cytogenetic finding in pediatric polymorphic PTLD, may be a recurrent cytogenetic aberration if confirmed in a larger study of pediatric PTLDs. Further clinical follow up might help stratify significance of trisomy 3 as a prognostic factor.

Post Transplant Lymphoproliferative Disorder risk factors in children: Analysis of a 23-year single-institutional experience

INTRODUCTION

PTLD is the most frequent malignancy following SOT in children and the second most common SOT complication in adults. However, factors determining outcomes in children are poorly understood due to its relative rarity.

METHODS

This study was performed at the University of Florida. Univariate and multivariate analyses were used to identify prognostic factors in pediatric patients diagnosed with PTLD.

RESULTS

We reviewed records of 54 pediatric (younger than 18 years old at diagnosis) patients diagnosed with PTLD from 1994 to 2017. The median follow-up was 28.8 months. The estimated 5-year survival rate was 87.6% (95% CI 74.3-94.2%). Univariate analysis showed that organ transplanted (specifically heart transplant), poor response to initial treatment, allograft rejection, and low Karnofsky score were statistically significant for negative prognostic factors in determining survival. Multivariate analysis determined progression in response to initial treatment and presence of allograft rejection as statistically significant prognostic factors affecting overall survival. We found no statistically significant impact of EBV serological status on PTLD prognosis.

CONCLUSIONS

Disease progression and allograft rejection were strong negative prognostic indicators in our study cohort. Close attention to graft status and development of therapies that protect the graft from rejection while bolstering anti-EBV immunity will be essential to further improving PTLD outcomes in children.

Epstein-Barr virus infections are strongly dependent on activating and inhibitory KIR-HLA pairs after T-cell replate unrelated hematopoietic stem cell transplantation, the principles, and method of pairing analysis

Viral infections are the main cause of increased morbidity and mortality among recipients in allogeneic hematopoietic stem cell transplantation (HSCT). Natural killer (NK) cells fight virally infected cells provided directional activation of cytotoxicity. In this study, we analyzed the role of receptor-ligand pairs that include inhibitory or activating killer cell immunoglobulin-like receptors (KIRs) with their HLA class I ligands in the course of viral infections. The paper also presents an algorithm that allows performing automated inhibitory (i) KIR:HLA pairing and rechecking in the clinical setting. The obtained results indicate a significant adverse roles of reduced number of iKIR:HLA pairs (40% vs 9%; odds ratio [OR] = 6.67; P = .0057; 95% confidence interval [CI] 1.74-25.62) and the presence of activating KIR:HLA pairs (15% vs 5%, OR = 3.58, P = .028, 95% CI 1.19-10.73) in EBV infections post HSCT.

Post-transplantation lymphoproliferative disorders: Current concepts and future therapeutic approaches

Transplant recipients are vulnerable to a higher risk of malignancy after solid organ transplantation and allogeneic hematopoietic stem-cell transplant. Post-transplant lymphoproliferative disorders (PTLD) include a wide spectrum of diseases ranging from benign proliferation of lymphoid tissues to frank malignancy with aggressive behavior. Two main risk factors of PTLD are: Firstly, the cumulative immunosuppressive burden, and secondly, the oncogenic impact of the Epstein-Barr virus. The latter is a key pathognomonic driver of PTLD evolution. Over the last two decades, a considerable progress has been made in diagnosis and therapy of PTLD. The treatment of PTLD includes reduction of immunosuppression, rituximab therapy, either isolated or in combination with other chemotherapeutic agents, adoptive therapy, surgical intervention, antiviral therapy and radiotherapy. In this review we shall discuss the prevalence, clinical clues, prophylactic measures as well as the current and future therapeutic strategies of this devastating disorder.

Posttransplant Lymphoproliferative Disorder in Children: A 360-degree Perspective

An earlier incorrect version of this article appeared online. This article was corrected on December 17, 2019.

Late-Onset Central Nervous System Posttransplant Lymphoproliferative Disorder After Lung Transplantation:A Case Report

Posttransplant lymphoproliferative disorder (PTLD) is caused by uncontrolled proliferation of lymphoid cells after a hematopoietic stem cell or solid organ transplant procedure related to the Epstein-Barr virus (EBV) infection. A primary central nervous system (CNS) PTLD (CNS-PTLD) is rare and important to distinguish from an intracranial lesion after transplantation. A 66-year-old man with pulmonary arterial hypertension who underwent living-donor lung transplantation 9 years prior noticed disorientation regarding route and dates. Brain magnetic resonance imaging revealed multiple white matter lesions and fluorodeoxyglucose (FDG) positron emission tomography showed FDG uptake in the brain and skin. CNS-PTLD was diagnosed by craniotomy biopsy and EBV-encoded RNA was positive in in situ hybridization findings and elevated in brain tissue. The treatment was started with immunosuppressant reduction and whole brain radiotherapy. But the condition progressed rapidly over 2 months after the first symptom and the patient was passed away 25 days after hospitalization. CNS-PTLD can occur several years after transplantation and it is necessary to keep in mind to distinguish brain disease because early diagnosis and treatment are important.

Post-transplant lymphoproliferative disorders, Epstein-Barr virus infection, and disease in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

PTLD with the response-dependent sequential use of RIS, rituximab, and cytotoxic chemotherapy is recommended. Evidence gaps requiring future research and alternate treatment strategies including immunotherapy are highlighted.

Various initial presentations of Epstein-Barr virus infection-associated post-transplant lymphoproliferative disorder in pediatric liver transplantation recipients: Case series and literature review

PTLD is a rare but potentially life-threatening condition, which shows a higher prevalence in children than in adults. From 129 children who underwent LT, we reported 5 cases with biopsy-proven PTLD at a single teaching hospital. Four patients had shared clinical presentations including fever, lymphadenopathy, and splenomegaly. They were noted to be given a prolonged course of IS due to the management of comorbid complications such as acute cellular rejection or severe food allergy or eosinophilic gastrointestinal disease. The other one patient presented with upper gastrointestinal bleeding from gastric mass during an early post-transplantation period. Notably, hypoalbuminemia was noted in all reported patients. Similar to previous studies, both EBV serology mismatch between the donor and recipient with high EBV viral load were noted in all except one case, whose EBV serology was unknown before LT. At least one episode of CMV reactivation was also observed in 3 of 5 patients prior to the PTLD diagnosis. The histopathology revealed 1 of 5 early PTLD, 1 of 5 polymorphic PTLD, and 3 of 5 monomorphic PTLD. The treatment included IS withdrawal, chemotherapy, and/or rituximab. One patient died of multiorgan dysfunction, one remains in complete remission, and three patients are either still on treatment or await response evaluation. Even though most of our reported PTLD cases had shared manifestations with fever, lymphadenopathy, splenomegaly, EBV serology mismatch, and high EBV viral load, various initial presentations such as respiratory symptoms, hypoalbuminemia, and prolonged use of IS from other causes such as significant food allergy were noted.

Post-transplantation lymphoproliferative disease in pediatric liver recipients in Taiwan

BACKGROUND

Post-transplantation lymphoproliferative disorder (PTLD) is a heterogeneous, potentially life-threatening complication after liver transplantation in children. In this study, the disease characteristics, outcomes, and prognostic factors of PTLD were investigated.

METHODS

A retrospective, observational study was conducted on 16 pediatric liver transplant (LT) recipients who developed PTLD between February 2001 and December 2013 at a tertiary referral center in Taiwan. The disease characteristics and treatment outcomes of the patients were analyzed.

RESULTS

The median time from liver transplantation to the development of PTLD was 8 months. Early onset (<1 year post-transplantation) PTLD constituted 62.5% of the cases. PTLD location was frequently extranodal (81.3%) and mostly involved the gastrointestinal tract (68.8%). Histopathologic findings showed polymorphic PTLD in six cases (37.5%), diffuse large B-cell lymphoma in five cases (31.3%), and Burkitt's PTLD in two cases (12.5%). Early lesions in PTLD, T-cell lymphoma, and Hodgkin's lymphoma were observed in one case each (6.3%). Overall survival at 1- and 5-years post-PTLD diagnosis was 87.5% and 79.5%, respectively. St Jude's classification stage IV disease was associated with poor survival (hazard ratio [HR] = 13.37, P = 0.037). Two patients (12.5%) had chronic rejection after the treatment for PTLD and one patient (6.3%) developed graft failure.

CONCLUSION

PTLD is a major complication in pediatric LT recipients, but long-term survival is possible in most cases with an adequate treatment strategy. Stage IV disease is a major risk factor for poor survival in pediatric PTLD patients. During the management of PTLD, the possibility of chronic rejection and even graft failure should be considered.

Treatment of Epstein-Barr virus associated central nervous system diseases after allogeneic hematopoietic stem cell transplantation with intrathecal donor lymphocyte infusion

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective measure for the treatment of hematological disease. With the progress and widespread use of allo-HSCT, Epstein-Barr virus (EBV) related central nervous system (CNS) diseases have gotten more and more attention because of its poor prognosis and overall survival. Since currently there is no standard treatment for patients with EBV-associated CNS diseases and reported therapies are heterogeneous with mixed results, we attempted to develop a novel therapeutic method. We applied a regimen of intrathecal donor lymphocyte infusion (IDLI) in three patients with EBV-associated CNS diseases after allo-HSCT in addition to immunosuppressants reduction and combined antiviral therapy. All of three patients were responsive to this therapy: all clinical symptoms and EBV load in CSF were resolved 10, 17, and 12 days after initial IDLI, respectively, and magnetic resonance imaging (MRI) showed that lesions of case 1 and 2 disappeared 15 and 19 days after initial IDLI, respectively. Even more appealing, there were no acute or chronic adverse reactions during the infusion and up to 23 months of follow-up. In conclusion, IDLI seems to be an effective and safe method for EBV-associated CNS diseases in allo-HSCT recipients. We recommend this treatment modality for further investigation.

Dissecting Epstein-Barr Virus-Specific T-Cell Responses After Allogeneic EBV-Specific T-Cell Transfer for Central Nervous System Posttransplant Lymphoproliferative Disease

Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disease (PTLD) with central nervous system (CNS) involvement is a severe complication after solid organ transplantation. Standard treatment with reduction of immunosuppression and anti-CD20 antibody application often fails leading to poor outcome. Here, we report the case of an 11-year-old boy with multilocular EBV-positive CNS PTLD 10 years after liver transplantation. Complete remission was achieved by repeated intravenous and intrathecal anti-CD20 antibody rituximab administration combined with intrathecal chemotherapy (methotrexate, cytarabine, prednisone) over a time period of 3 months. Due to the poor prognosis of CNS PTLD and lack of EBV-specific T-cells (EBV-CTLs) in patient's blood, we decided to perform EBV-directed T-cell immunotherapy as a consolidating treatment. The patient received five infusions of allogeneic EBV-CTLs from a 5/10 HLA-matched unrelated third-party donor. No relevant acute toxicity was observed. EBV-CTLs became detectable after first injection and increased during the treatment course. Next-generation sequencing (NGS) TCR-profiling verified the persistence and expansion of donor-derived EBV-specific clones. After two transfers, epitope spreading to unrelated EBV antigens occurred suggesting onset of endogenous T-cell production, which was supported by detection of recipient-derived clones in NGS TCR-profiling. Continuous complete remission was confirmed 27 months after initial diagnosis.

Systematic review and meta-analysis of post-transplant lymphoproliferative disorder in lung transplant recipients

A systematic review of papers in English on post-transplant lymphoproliferative disorder (PTLD) in lung transplant recipients (LTR) using MEDLINE, EMBASE, SCOPUS, and Cochrane databases was performed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations were strictly adhered to. Pooled odds ratios (pOR) were calculated from a random-effects model, and heterogeneity among studies was quantitated using I² values. Fourteen studies published from 2005 to 2015 were included in the meta-analysis. One hundred and sixty-four lung transplant recipients were included. LTRs who received single vs bilateral were associated with a 7.67-fold risk of death after PTLD (6 studies with 64 LTRs; pOR 7.67 95% CI 1.98-29.70; P = .003). pOR of death for early onset PTLD (<1 year post-LT) vs late onset (>1 year post-LT) was not different (3 studies with 72 LTRS; pOR 0.62, 95% CI 0.20-1.86, P = .39). Standardized mean difference (SMD) in time from transplant to PTLD onset between LTRs who died vs alive was not different (9 studies with 109 LTRs; SMD 0.03, 95% CI -0.48-0.53, P = .92). Survival in polymorphic vs monomorphic PTLD and extranodal vs nodal disease was similar (4 studies with 31 LTRs; pOR 0.44, 95% CI 0.08-2.51; P = .36. 6 studies with 81 LTRs; pOR 1.05 95% CI 0.31-3.52, P = .94). This meta-analysis demonstrates that single LTRs are at a higher risk of death vs bilateral LTRs after the development of PTLD.

Epstein-Barr Virus+ Smooth Muscle Tumors as Manifestation of Primary Immunodeficiency Disorders

Epstein–Barr virus positive (EBV⁺) smooth muscle tumors (SMTs) constitute a very rare oncological entity. They usually develop in the context of secondary immunodeficiency caused by human immunodeficiency virus infection or immunosuppressive treatment after solid organ transplantation. However, in a small fraction of predominantly pediatric patients, EBV⁺ SMTs may occur in patients with primary immunodeficiency disorders (PIDs), such as GATA2 and CARMIL2 deficiency. In secondary immunodeficiencies and when the underlying condition can not be cured, the treatment of EBV⁺ SMTs is based on surgery in combination with antiretroviral and reduced or altered immunosuppressive pharmacotherapy, respectively. Importantly, without definitive reconstitution of cellular immunity, long-term survival is poor. This is particularly relevant for patients with EBV⁺ SMTs on the basis of PIDs. Recently, allogeneic hematopoietic stem cell transplantation resulted in cure of immunodeficiency and EBV⁺ SMTs in a GATA2-deficient patient. We propose that in the absence of secondary immunodeficiency disorders patients presenting with EBV⁺ SMTs should be thoroughly evaluated for PIDs. Allogeneic hematopoietic stem cell transplantation should be taken into consideration, ideally in the setting of a prospective clinical trial.

Personalized adoptive immunotherapy for patients with EBV-associated tumors and complications: Evaluation of novel naturally processed and presented EBV-derived T-cell epitopes

Morbidity and mortality of immunocompromised patients are increased by primary infection with or reactivation of Epstein-Barr virus (EBV), possibly triggering EBV⁺ post-transplant lymphoproliferative disease (PTLD). Adoptive transfer of EBV-specific cytotoxic T cells (EBV-CTLs) promises a non-toxic immunotherapy to effectively prevent or treat these complications. To improve immunotherapy and immunomonitoring this study aimed at identifying and evaluating naturally processed and presented HLA-A*03:01-restricted EBV-CTL epitopes as immunodominant targets. More than 15000 peptides were sequenced from EBV-immortalized B cells transduced with soluble HLA-A*03:01, sorted using different epitope prediction tools and eleven candidates were preselected. T2 and Flex-T peptide-binding and dissociation assays confirmed the stability of peptide-MHC complexes. Their immunogenicity and clinical relevance were evaluated by assessing the frequencies and functionality of EBV-CTLs in healthy donors (n > 10) and EBV⁺ PTLD-patients (n = 5) by multimer staining, Eli- and FluoroSpot assays. All eleven peptides elicited EBV-CTL responses in the donors. Their clinical applicability was determined by small-scale T-cell enrichment using Cytokine Secretion Assay and immunophenotyping. Mixtures of these peptides when added to the EBV Consensus pool revealed enhanced stimulation and enrichment efficacy. These EBV-specific epitopes broadening the repertoire of known targets will improve manufacturing of clinically applicable EBV-CTLs and monitoring of EBV-specific T-cell responses in patients.

Post-transplant lymphoproliferative disorder (PTLD): single institutional experience of 141 patients

Background

Post-transplant lymphoproliferative disorder is a well-recognized but rare complication of hematopoietic stem cell and solid organ transplant. Due to rarity of this disease, retrospective studies from major transplant centers has been the main source to provide treatment guidelines, which are still in evolution. The sample size of this study is among one of the largest study on PTLD till date reported throughout the world.

Methods

This study was performed at University of Florida which is one of the largest transplant center in South East United States. We performed treatment and survival analysis along with univariate and multivariate analysis to identify prognostic factors.

Results

We reviewed 141 patients diagnosed with PTLD over last 22 years with median follow-up of 2.4 years. The estimated median overall survival of the entire group was 15.0 years. Sub group analysis showed that 5-year overall survival rates of pediatric population were 88% (median not reached). For adults, median OS was 5.35 years while for elderly patients it was 1.32 years. The estimated median OS of patients with monomorphic PTLD was 9.0 years while in polymorphic PTLD was 19.3 years. Univariate analysis identified gender, age at transplant and PTLD diagnosis, performance status, IPI score, allograft type, recipient EBV status, multiple acute rejections prior to PTLD diagnosis, PTLD sub-type, extra-nodal site involvement, immunosuppressive drug regimen at diagnosis, initial treatment best response were statistically significant prognostic factors (p < 0.05). On multivariate analysis, age at PTLD diagnosis, recipient EBV status, bone marrow involvement, and initial best response were statistically significant prognostic factors (p < 0.05). Surprisingly, use of Rituximab alone as upfront therapy had poor hazard ratio in the cumulative group as well less aggressive PTLD subgroup comprising of early lesions and polymorphic PTLD.

Conclusions

Our experience with treatment and analysis of outcomes does challenge current role of Rituximab use in treatment of PTLD. Currently as we define role of immunotherapy in cancer treatment, the role of acute rejections and immunosuppressant in PTLD becomes more relevant as noticed in our study. This study was also able to find new prognostic factors and also verified other known prognostic factors.

Post-transplant lymphoproliferative disorder after solid-organ transplant in children

The post-transplant lymphoproliferative disorders (PTLD) are a diverse group of potentially life-threatening conditions affecting organ transplant recipients. PTLD arises in the setting of an attenuated host immunologic system that is manipulated to allow a foreign graft but then fails to provide adequate immune surveillance of transformed malignant or premalignant lymphocytes. The diversity of biological behavior and clinical presentation makes for a challenging clinical situation for those involved in the care of children with PTLD occurring after solid-organ transplantation. This review details a large transplant center's multidisciplinary approach to monitoring for PTLD and systematic approach to intervention, which has been essential for early recognition and successful treatment.

Post-transplant lymphoproliferative disorder after liver transplantation: Incidence, long-term survival and impact of serum tacrolimus level

AIM

To investigate incidence and survival of post-transplant lymphoproliferative disorder (PTLD) patients after liver transplantation.

METHODS

A cross-sectional survey was conducted among patients who underwent liver transplantation at Shiraz Transplant Center (Shiraz, Iran) between August 2004 and March 2015. Clinical and laboratory data of patients were collected using a data gathering form.

RESULTS

There were 40 cases of PTLD in the pediatric age group and 13 cases in the adult group. The incidence of PTLD was 6.25% in pediatric patients and 1.18% in adult liver transplant recipients. The post-PTLD survival of patients at 6 mo was 75.1% ± 6%, at 1 year was 68.9% ± 6.5% and at 5 years was 39.2% ± 14.2%. Higher serum tacrolimus level was associated with lower post-PTLD survival in pediatric patients (OR = 1.07, 95%CI: 1.006-1.15, P = 0.032). A serum tacrolimus level over 11.1 ng/mL was predictive of post PTLD survival (sensitivity = 90%, specificity = 52%, area under the curve = 0.738, P = 0.035).

CONCLUSION

Incidence of PTLD in our liver transplant patients is comparable to other centers. Transplant physicians may consider adjustment of tacrolimus dose to maintain its serum level below this cutoff point.

Primary CNS lymphoproliferative disease, mycophenolate and calcineurin inhibitor usage

Immunosuppression for solid organ transplantation increases lymphoproliferative disease risk. While central nervous system (CNS) involvement is more rare, we noticed an increase in primary CNS (PCNS) disease. To investigate a potential association with the immunosuppressive regimen we identified all post-transplant lymphoproliferative disease (PTLD) cases diagnosed over a 28-year period at our institution (174 total, 29 PCNS) and all similar cases recorded in a United Network for Organ Sharing-Organ Procurement and Transplant Network (UNOS-OPTN) datafile. While no PCNS cases were diagnosed at our institution between 1986 and 1997, they comprised 37% of PTLD cases diagnosed from 2011-2014. PCNS disease was more often associated with renal vs. other organ transplant, Epstein-Barr virus, large B-cell morphology and mycophenolate mofetil (MMF) as compared to PTLD that did not involve the CNS. Calcineurin inhibitors were protective against PCNS disease when given alone or in combination with MMF. A multivariate analysis of a larger UNOS-OPTN dataset confirmed these findings, where both MMF and lack of calcineurin inhibitor usage were independently associated with risk for development of PCNS PTLD. These findings have significant implications for the transplant community, particularly given the introduction of new regimens lacking calcineurin inhibitors. Further investigation into these associations is warranted.

Primary Central Nervous System Posttransplant Lymphoproliferative Disease in a Bilateral Transfemoral Lower Extremity Transplantation Recipient

Posttransplant lymphoproliferative disorder (PTLD) is a heterogeneous group of clinical and pathological entities characterized by malignant lymphoid cell proliferation occurring after solid organ transplantation, with frequent extranodal involvement. Central nervous system (CNS) involvement occurs in 7-15% of the cases and it is a significant negative prognostic factor. A case of primary CNS (PCNS) PTLD in the first bilateral lower limb transplant recipient is presented.

The Impact of EBV Status on Characteristics and Outcomes of Posttransplantation Lymphoproliferative Disorder

We examined the associations of Epstein-Barr virus (EBV) status with characteristics and outcomes of posttransplantation lymphoproliferative disorder (PTLD) by studying 176 adult solid organ transplant recipients diagnosed with PTLD between 1990 and 2013 (58 [33%] EBV-negative; 118 [67%] EBV-positive). The proportion of EBV-negative cases increased over time from 10% (1990-1995) to 48% (2008-2013) (p < 0.001). EBV-negative PTLD had distinct characteristics (monomorphic histology, longer latency) though high-risk features (advanced stage, older age, high lactate dehydrogenase, central nervous system involvement) were not more common compared to EBV-positive PTLD. In multivariable analysis, EBV negativity was not significantly associated with worse response to initial therapy (adjusted odds ratio, 0.84; p = 0.75). The likelihood of achieving a complete remission (CR) was not significantly different for EBV-negative versus EBV-positive PTLD including when therapy was reduction of immunosuppression alone (35% vs. 43%, respectively, p = 0.60) or rituximab (43% vs. 47%, p = 1.0). EBV negativity was also not associated with worse overall survival (adjusted hazard ratio, 0.91; p = 0.71). Our findings indicate that EBV status is not prognostic or predictive of treatment response in adults with PTLD. The high proportion of EBV-negative disease diagnosed in recent years highlights the need for new strategies for prevention and management of EBV-negative PTLD.

Dose-level response rates of mTor inhibition in tuberous sclerosis complex (TSC) related subependymal giant cell astrocytoma (SEGA)

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant multisystem disease usually diagnosed in childhood. Subependymal giant cell astrocytomas (SEGA) are benign brain lesions occurring in up to 20% of patients with TSC. Treatment with mTOR inhibitors has been proven effective in inducing SEGA shrinkage, but discontinuation results in re-growth. Evidence suggests that mTOR inhibition seems a disease-modifying treatment for TSC beyond inducing SEGA shrinkage; however concerns remain regarding negative long-term effects.

METHODS

Through this retrospective case series, an attempt was made to determine the minimal mTOR inhibitor dose needed to maintain radiological response of SEGA in six pediatric patients treated at The Hospital for Sick Children since 2007. This study reviews medication doses and blood levels as related to SEGA size on MRIs at 3-month intervals. Blood levels were monitored every 3 months and 2 weeks after dose adjustment. Total dose reduction by 25% was considered after SEGA shrinkage was maintained on two consecutive MRIs.

RESULTS

All patients demonstrated SEGA shrinkage greater than 50% when treated with mTOR inhibition at therapeutic doses (4-5 mg/m(2)). When sirolimus doses were weaned in two patients by 50%, SEGAs regrew by 84% and 32%. In two patients, responses have been maintained with 30% decrease in sirolimus dose. One patient underwent SEGA resection and one remains on therapeutic dose.

CONCLUSIONS

Therapeutic dose of mTOR inhibitor is effective in shrinking TSC-related SEGAs. Doses less than 2.5 mg/m(2) were insufficient to maintain response in this limited series.

High incidence of Epstein-Barr virus (EBV)-positive Hodgkin lymphoma and Hodgkin lymphoma-like B-cell lymphoproliferations with EBV latency profile 2 in children with interleukin-2-inducible T-cell kinase deficiency

AIMS

Interleukin-2-inducible T-cell kinase (ITK) deficiency is an inherited T-cell deficiency characterized by the development of Epstein-Barr virus (EBV)-associated lymphoproliferations. We aimed to describe the histopathological features of lymphoproliferative processes arising in ITK deficiency, and to compare them with lymphoproliferations in otherwise immunocompromised patients.

METHODS AND RESULTS

We revised the histopathological diagnoses of 12 biopsies of lymphoproliferations from seven ITK-deficient children according to the World Health Organization criteria, and determined the EBV latency types and lytic activity by staining for EBV-encoded small RNA, latent membrane protein 1, EBV nuclear antigen 2, and ZEBRA. We found polymorphic and borderline polymorphic to monomorphic B-cell lymphoproliferations with variable contents in large cells (five cases), a Hodgkin-like B-cell proliferation (one case), and classic mixed-cellularity Hodgkin lymphoma (six cases). All cases (12/12) were EBV-positive. The Hodgkin lymphoma-like and Hodgkin lymphoma, and all but one polymorphic B-cell lymphoproliferation, showed EBV latency type 2, as observed in classic EBV-positive Hodgkin lymphoma.

CONCLUSIONS

The 100% EBV association, the high percentage of EBV-positive classic Hodgkin lymphoma and Hodgkin-like B-cell proliferations and the predominance of EBV latency type 2 even in polymorphic lesions are the main features of lymphoproliferations in patients with ITK deficiency, and suggest a unique pathomechanism of lymphomagenesis in this T-cell immunodeficiency.

Post-transplant lymphoproliferative disorders

Post-transplant lymphoproliferative disorders (PTLD) are a serious complication after solid organ or allogeneic hematopoietic stem cell transplantation and include a range of diseases from benign proliferations to malignant lymphomas. Risk factors for developing PTLD include Epstein-Barr virus (EBV) infection, recipient age, transplanted organ, type of immunosuppression, and genetics. Uncontrolled proliferation of EBV-infected B cells is implicated in EBV-positive PTLD, whereas the pathogenesis of EBV-negative PTLD may be similar to non-Hodgkin's lymphoma in the general population. The World Health Organization (WHO) classifies PTLD into four categories: early lesions, polymorphic PTLD, monomorphic PTLD, and classical Hodgkin's lymphoma (cHL). Treatment is aimed at cure of PTLD, while maintaining transplanted organ function. However, there are no established guidelines for the treatment of PTLD. Immune suppression reduction (ISR) is the first line of treatment in most cases, with more recent data suggesting early use of rituximab. In more aggressive forms of PTLD, upfront chemotherapy may offer a better and more durable response. Sequential therapy using rituximab followed by chemotherapy has demonstrated promising results and may establish a standard of care. Novel therapies including anti-viral agents, adoptive immunotherapy, and monoclonal antibodies targeting cytokines require further study in the prevention and treatment of PTLD.

Successful treatment of systemic and central nervous system post-transplant lymphoproliferative disorder without the use of high-dose methotrexate or radiation

Post-transplant lymphoproliferative disorder (PTLD) describes a spectrum of conditions with highest incidence in the first year post-solid organ transplant in pediatric patients. Central nervous system (CNS) involvement with PTLD carries high mortality risk with no consensus on optimal therapeutic regimen. We present the case of a 7-year old heart transplant patient diagnosed with widespread monomorphic, CD20+, Epstein-Barr virus-positive PTLD, including CNS involvement. In addition to immunosuppression reduction and rituximab, she was treated with multiagent systemic and intrathecal chemotherapy. She achieved a prompt and complete clinical and radiologic remission, which has been sustained for over 46 months since diagnosis.

Malignancies after pediatric kidney transplantation: more than PTLD?

Post-transplant lymphoproliferative disease (PTLD) is the most frequent malignant complication of transplantation in childhood. Even with modern post-transplant immunosuppressive strategies, 1-2% of all kidney transplant recipients will develop PTLD within the first 5 years after transplantation, and the risk remains high even thereafter as long as immunosuppression is required. In addition to PTLD, adult kidney transplant recipients have an increased incidence of other immunosuppression-related malignancies, such as non-melanoma skin cancer or Kaposi's sarcoma. It is foreseeable that pediatric transplant recipients will face similar complications during their adult life. Not only immunosuppression but also other risk factors have been identified for some of these malignancies. Strategies addressing these risk factors during childhood may contribute to life-long cancer prevention. Furthermore, early recognition and regular screening may facilitate early diagnosis and treatment, thereby reducing transplant-related morbidity. In this review we focus on malignant complications after renal transplantation and discuss known risk factors. We also review current screening strategies for malignancies during post-transplant follow-up.