A single-center experience of post-transplant lymphomas involving the central nervous system with a review of current literature

Effective management of primary central nervous system posttransplant lymphoproliferative disorder in a kidney transplant recipient using surgery and rituximab, along with a literature review

BACKGROUND

Primary central nervous system post-transplant lymphoproliferative disorder (PCNS-PTLD) is a rare but severe complication following solid organ transplantation (SOT). Currently, treatment regimens still lack clear guidelines.

METHODS

A kidney transplant recipient with PCNS-PTLD was reported in this case study, who treated with rituximab after transplant surgery. What's more, PubMed was used to find case series related to PCNS-PTLD.

RESULTS

The patient of this case report experienced complete remission (CR) following resection and treatment with rituximab. A total of 130 cases were extracted from 20 articles and were combined with one case from our institution. Out of 131 patients with PCNS-PTLD, the median duration between SOT and PTLD was 48 months. The majority (83 %) of patients had received a kidney transplant, with 74.8 % showing monomorphic histology and 93 % having an EBV+ tumor. Most patients (95 %) had reduction in immunosuppression as part of their first-line treatment. Other initial treatments consisted of high-dose methotrexate (HD-MTX) (46 %), high-dose cytarabine (HDAC) (26 %), and/or rituximab (47 %). The Overall Response Rate (ORR) was 63 %, showing that HD-MTX and/or HDAC-based therapy had the highest rates of ORR and CR. Roughly half of the participants experienced prolonged survival. After 36 months of observation, the median progression free survival (PFS) was 10 months and the overall survival (OS) was 18 months.

CONCLUSION

The use of HD-MTX and HDAC showed promise in treating PCNS-PTLD, but rituximab may also a potential drug for the PCNS-PTLD. Research should continue to investigate the alternative treatments for this condition.

Patterns of belatacept use and risk of post-transplant lymphoproliferative disorder in US kidney transplant recipients: An analysis of the Organ Procurement and Transplantation Network database

BACKGROUND

Belatacept is approved for the prophylaxis of organ rejection in Epstein-Barr virus (EBV)-seropositive kidney transplant recipients and is associated with a risk of post-transplant lymphoproliferative disorder (PTLD).

METHODS

Data from the Organ Procurement and Transplantation Network were used to examine patterns of belatacept use, describe patient characteristics, and estimate risk of PTLD in EBV-seropositive, kidney-only transplant recipients receiving belatacept- or calcineurin inhibitor (CNI)-based immunosuppression as part of US Food and Drug Administration-mandated safety monitoring.

RESULTS

During the study period (June 15, 2011-June 14, 2016), 94.9% (1631/1719) of belatacept-treated and 89.7% (59,992/66,905) of CNI-treated patients with known EBV serostatus were EBV seropositive. Among EBV-seropositive patients, 50.2% (belatacept) and 56.8% (CNI) received a standard criteria donor kidney, 59.5% and 18.7% received basiliximab induction, and 22.9% and 50.8% received antithymocyte globulin induction. PTLD developed in nine belatacept-treated patients (two with central nervous system [CNS] involvement) and 225 CNI-treated patients (nine with CNS involvement). Four and 81 patients, respectively, died due to PTLD. Kaplan-Meier analysis did not show a significant between-group difference in PTLD estimated incidence rates within 5 years (0.70% versus 0.48%, respectively; p = 0.18). Additionally, estimated PTLD incidence was not significantly different between treatment groups in a propensity score matched cohort.

CONCLUSIONS

The majority of adult kidney-only transplant recipients treated with belatacept in routine clinical practice are EBV seropositive. In this study, the risk of PTLD in these patients, while higher than for CNI-based immunosuppression, remained low after adjusting for differences in patient characteristics.

TRIAL REGISTRATION

These studies are registered at ClinicalTrials.gov: NCT01670058 and NCT01656343.

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.

Growth Transformation of B Cells by Epstein-Barr Virus Requires IMPDH2 Induction and Nucleolar Hypertrophy

The in vitro growth transformation of primary B cells by Epstein-Barr virus (EBV) is the initial step in the development of posttransplant lymphoproliferative disorder (PTLD). We performed electron microscopic analysis and immunostaining of primary B cells infected with wild-type EBV. Interestingly, the nucleolar size was increased by two days after infection. A recent study found that nucleolar hypertrophy, which is caused by the induction of the IMPDH2 gene, is required for the efficient promotion of growth in cancers. In the present study, RNA-seq revealed that the IMPDH2 gene was significantly induced by EBV and that its level peaked at day 2. Even without EBV infection, the activation of primary B cells by the CD40 ligand and interleukin-4 increased IMPDH2 expression and nucleolar hypertrophy. Using EBNA2 or LMP1 knockout viruses, we found that EBNA2 and MYC, but not LMP1, induced the IMPDH2 gene during primary infections. IMPDH2 inhibition by mycophenolic acid (MPA) blocked the growth transformation of primary B cells by EBV, leading to smaller nucleoli, nuclei, and cells. Mycophenolate mofetil (MMF), which is a prodrug of MPA that is approved for use as an immunosuppressant, was tested in a mouse xenograft model. Oral MMF significantly improved the survival of mice and reduced splenomegaly. Taken together, these results indicate that EBV induces IMPDH2 expression through EBNA2-dependent and MYC-dependent mechanisms, leading to the hypertrophy of the nucleoli, nuclei, and cells as well as efficient cell proliferation. Our results provide basic evidence that IMPDH2 induction and nucleolar enlargement are crucial for B cell transformation by EBV. In addition, the use of MMF suppresses PTLD. IMPORTANCE EBV infections cause nucleolar enlargement via the induction of IMPDH2, which are essential for B cell growth transformation by EBV. Although the significance of IMPDH2 induction and nuclear hypertrophy in the tumorigenesis of glioblastoma has been reported, EBV infection brings about the change quickly by using its transcriptional cofactor, EBNA2, and MYC. Moreover, we present here, for the novel, basic evidence that an IMPDH2 inhibitor, namely, MPA or MMF, can be used for EBV-positive posttransplant lymphoproliferative disorder (PTLD).

Important Considerations in the Diagnosis and Management of Post-transplant Lymphoproliferative Disorder

PURPOSE OF REVIEW

A relative lack of molecular and clinical studies compared to other lymphoid cancers has historically made it difficult to determine optimal management approaches in post-transplant lymphoproliferative disorder (PTLD). We sought to better define the "state of the science" in PTLD by examining recent advances in risk assessment, genomic profiling, and trials of PTLD-directed therapy.

RECENT FINDINGS

Several major clinical trials highlight risk-stratified sequential therapy incorporating rituximab with or without chemotherapy as a rational treatment strategy in patients with CD20+ PTLD who do not respond to reduction of immunosuppression alone. Epstein Barr virus (EBV)-targeted cytotoxic lymphocytes are a promising approach in patients with relapsed/refractory EBV+ PTLD, but dedicated clinical trials should determine how autologous chimeric antigen receptor T cell therapy (CAR-T) may be safely administered to PTLD patients. Sequencing studies underscore the important effect of EBV infection on PTLD pathogenesis, but comprehensive genomic and tumor microenvironment profiling are needed to identify biomarkers that predict response to treatment in this clinically heterogeneous disease.

Successful Treatment of Central Nervous System Post-Transplant Lymphoproliferative Disease With a Reduced Dose of High-Dose Methotrexate

Post-transplant lymphoproliferative disease (PTLD) is a complication of solid organ and hematopoietic stem cell transplantation that occurs as a result of immunosuppression. PTLD isolated to the central nervous system (CNS) is a rare disease and it presents with nonspecific signs and symptoms. Optimal therapy guidelines have not yet been established for CNS PTLD. Here, we report a case of successful treatment of CNS PTLD in an adult female following two subsequent kidney transplants. Initial management was with immunosuppression reduction and a trial of rituximab. There were concerns regarding using methotrexate (MTX) given the patient's fragile transplant status. Magnetic resonance imaging of the brain following four cycles of rituximab revealed the progression of the disease. Subsequently, high-dose MTX (HD-MTX) was considered within the constraints of potential kidney toxicities given her transplant status and chronic kidney disease. Potential toxicities from other therapies, such as brain radiation, also factored into the final decision. The patient was treated with one cycle of a combination of rituximab and HD-MTX 1 g/m². The patient tolerated HD-MTX and did not have evidence of renal toxicity in laboratory studies. Following that, she was started on a reduced dose of HD-MTX at 2 g/m² every two weeks instead of the higher MTX dose range of 3.5 to 8 g/m², which was a shared decision with the patient and nephrology after weighing the risk of kidney dysfunction with the possibility of a less than optimal response with regards to her lymphoma. She was followed with a magnetic resonance imaging of the brain, which demonstrated a complete response after four cycles. Further consolidation treatments with HD-MTX 2 g/m² every four weeks were administered to complete one year of treatment. Following the completion of chemotherapy, the patient was able to achieve and maintain a complete response without affecting her kidney function. She continues to do well one year following treatment. This case highlights the significance of tailoring therapy to each individual based on their comorbidities and clinical response, as well as the possible merit in exploring the use of a reduced dose of HD-MTX in the treatment of CNS PTLD in patients at high risk for renal toxicity.

Immunosuppressive treatment and radiotherapy in kidney transplant patients: A systematic review

BACKGROUND

Immunosuppression (IS) therapy may contribute to cancer development. Some authors have proposed to reduce immunosuppression drugs dose in case of viral infections, in immunosuppression-related diseases, and in patients undergoing radiotherapy. The present analysis reports the results of a systematic review on kidney transplant recipients undergoing immunosuppression and radiotherapy.

AIM

To define if it is necessary reduce immunosuppression drugs during radiotherapy.

METHODS

The literature search was based on three electronic databases (Pubmed, Scopus, and Web of Science) using selected keywords linked through the "AND" and "OR" Boolean operators to build specific strings for each electronic search engine. Two researchers independently screened the citations, and disagreement was resolved by discussion or through the intervention of a third author. The review was conducted and reported according to the PRISMA statement. Extracted data were narratively synthesized, and, where possible, frequencies, percentages, and ranges were calculated.

RESULTS

The literature search resulted in 147 citations. After abstracts screening, 21 records were selected for full-text evaluation. Fifteen of these were excluded, leaving six papers considered suitable for analysis. There is still no clear evidence that withdrawing antimetabolites and/or calcineurin inhibitors and/or mammalian target of rapamycin-inhibitors, as opposed to continuing maintenance IS, improves patient survival in kidney transplant recipients with cancer undergoing radiotherapy. Only few retrospective studies on small cancer patient cohorts are available in this setting, but without comparison of different immunosuppression treatments. Even where immunosuppression therapy was described, patient survival seemed to be correlated only with cancer stage and type.

CONCLUSION

The results of this systematic review do not support the reduction of immunosuppression dose in patients undergoing radiotherapy.

A Case of Central Nervous System Post-Transplant Lymphoproliferative Disorder Following Haploidentical Stem Cell Transplantation in a Patient With Acute Lymphoblastic Leukemia

We present a differential diagnosis of an intracranial lesion following haploidentical stem cell transplantation (haplo-SCT) in a female patient with acute lymphoblastic leukemia (ALL). This patient received an anti-CD19-chimeric antigen receptor (CAR) T-cell therapy for refractory B-cell ALL and obtained minimal residual disease (MRD)-positive (0.03%) complete remission (CR). Then the patient received a bridging therapy of haplo-SCT. After bridging therapy, the patient maintained MRD-negative and full donor chimerism in bone marrow (BM) and was negative for Epstein–Barr virus (EBV)-DNA copy in peripheral blood. At 91 days after haplo-SCT, the patient presented with dizziness and fatigue and magnetic resonance imaging (MRI) demonstrated an intracranial lesion. The diagnosis of isolated extramedullary relapse (IEMR) was temporarily considered. Then next-generation sequencing (NGS) identified positive EBV-DNA in the cerebrospinal fluid, although EBV-DNA in the peripheral blood was negative. Furthermore, the positive EBV-DNA by NGS and complete donor chimerism in the brain tissue confirmed the diagnosis of central nervous system post-transplant lymphoproliferative disorder (CNS-PTLD). However, the EBV-encoded small RNAs (EBERs) in situ hybridization was sparsely positive. The patient was subsequently treated with anti-CD22-CAR T cells in combination with Zanubrutinib, but the disease progressed quickly and died. Donor chimerism examination of focal biopsy provides important evidence for diagnosing PTLD. Furthermore, NGS detection of EBV-DNA in local lesions is more valuable for diagnosing PTLD than detection of EBV-DNA in the peripheral blood.

Trial registration: The patient was enrolled in a clinical trial of ChiCTR1800019622 and ChiCTR1800019298.

Incidence and mortality of post-transplant lymphoproliferative disorders after kidney transplantation: A real-world retrospective analysis in Japan

OBJECTIVES

Post-transplant lymphoproliferative disorder is a potentially life-threatening complication that has a greater risk of occurrence in the setting of immunosuppression and oncogenic viral infections after transplant surgery. Few studies have reported the cumulative incidence, histological subtypes and clinical outcomes of this disorder in kidney transplant recipients.

METHODS

We retrospectively investigated 34 post-transplant lymphoproliferative disorder patients diagnosed out of the 1210 kidney transplant recipients who had undergone the surgery at the two largest centers in Japan between January 1983 and December 2017.

RESULTS

A total of 32 patients (94.1%) developed late-onset post-transplant lymphoproliferative disorder (diagnosed 1 year after transplantation). The cumulative incidence rates were 0.76% and 1.59% at 5 and 10 years post-transplantation, respectively. The central nervous system was the most common site (35.3%, 12/34). Overall survival was similar between patients with and without central nervous system lesions (P = 0.676). Of all of the cases, 23.5% (8/34) were detected through cancer screening. Importantly, patients with screening-detected post-transplant lymphoproliferative disorder had better overall survival than those with the disorder who had been symptom detected (P = 0.0215). Overall survival was significantly reduced in patients who developed the disorder compared with those who did not (P = 0.0001).

CONCLUSIONS

Post-transplant lymphoproliferative disorder was more likely to occur in the late post-transplantation period, which showed that long-term medical examination for transplant recipients is required. Based on our findings, we propose vigilant, long-term, cancer screening in kidney transplant recipients.

Primary central nervous system lymphoma in a patient with neuropsychiatric systemic lupus erythematosus receiving mycophenolate mofetil: A case report and literature review

A 41-year-old woman with a 14-month history of systemic lupus erythematosus (SLE) presented with headache, aphasia, and agraphia. A laboratory examination revealed mild proteinuria, hypocomplementemia, and elevated anti-double-stranded DNA antibody levels. A cerebrospinal fluid analysis demonstrated elevated protein and interleukin-6 levels. Magnetic resonance imaging (MRI) of the brain identified multiple lesions suggestive of brain edemas and small haemorrhages. She was diagnosed as having neuropsychiatric lupus and lupus nephritis and received remission induction therapy with high-dose corticosteroid and intravenous cyclophosphamide. She achieved a complete remission, and treatment with mycophenolate mofetil (MMF) was initiated 3 months thereafter for remission maintenance. At 13 months after the exacerbation of SLE, she complained of headache and nausea. A gadolinium-enhanced MRI of the brain revealed a low-signal-intensity tumour with marginal ring enhancement of 50 mm in the left frontal lobe. The tumour was excised, and the histological diagnosis was diffuse large B-cell lymphoma with positive Epstein-Barr virus (EBV). MMF was discontinued. Remission induction therapy with rituximab, high-dose methotrexate, procarbazine, and vincristine was administered, and she achieved remission. Previous reports suggest that use of MMF is associated with primary central nervous system (CNS) lymphoma (PCNSL) in patients with lupus nephritis or other autoimmune diseases or in post-transplant patients. Our observation that PCNSL occurred after CNS involvement of SLE suggests that EBV and CNS inflammation arising from SLE might have contributed to the development of PCNSL.

Management of the kidney transplant patient with Cancer: Report from a Multidisciplinary Consensus Conference

INTRODUCTION

Cancer is the second most common cause of mortality and morbidity in Kidney Transplant Recipients (KTRs). Immunosuppression can influence the efficacy of cancer treatment and modification of the immunosuppressive regimen may restore anti-neoplastic immune responses improving oncologic prognosis. However, patients and transplant physicians are usually reluctant to modify immunosuppression, fearing rejection and potential graft loss. Due to the lack of extensive and recognised data supporting how to manage the immunosuppressive therapy in KTRs, in the context of immunotherapy, chemotherapy, radiotherapy and loco-regional treatments, a Consensus Conference was organised under the auspices of the European Society of Organ Transplantation and the Italian Society of Organ Transplantation. The conference involved a multidisciplinary group of transplant experts in the field across Europe.

METHODS

The overall process included a) the formulation of 12 specific questions based on the PICO methodology, b) systematic literature review and summary for experts for each question, c) a two-day conference celebration and the collection of experts' agreements. The conference was articulated in three sessions: "Immunosuppressive therapy and immunotherapy", "Systemic therapy", "Integrated Therapy", while the final experts' agreement was collected with a televoting procedure and defined according to the majority criterion.

RESULTS

Twenty-six European experts attended the conference and expressed their vote. A total of 14 statements were finally elaborated and voted. Strong agreement was found for ten statements, moderate agreement for two, moderate disagreement for one and uncertainty for the last one.

CONCLUSIONS

The consensus statements provide guidance to transplant physicians caring for kidney transplant recipients with cancer and indicate key aspects that need to be addressed by future clinical research.

Reduction of immunosuppression combined with whole-brain radiotherapy and concurrent systemic rituximab is an effective yet toxic treatment of primary central nervous system post-transplant lymphoproliferative disorder (pCNS-PTLD): 14 cases from the prospective German PTLD registry

Post-transplant lymphoproliferative disorders (PTLD) exclusively affecting the central nervous system-primary CNS-PTLD (pCNS-PTLD)-are rare. There is no standard therapy, and previous case series have included heterogeneous treatment approaches. We performed a retrospective, multi-centre analysis of 14 patients with pCNS-PTLD after solid organ transplantation (SOT) treated in the prospective German PTLD registry with reduction of immunosuppression (RI), whole-brain radiotherapy (WBRT), and concurrent systemic rituximab between 2001 and 2018. Twelve of fourteen patients were kidney transplant recipients and median age at diagnosis was 65 years. Thirteen of fourteen cases (93%) were monomorphic PTLD of the diffuse large B-cell lymphoma type, and 12/13 were EBV-associated. The median dose of WBRT administered was 40 Gy with a median fraction of 2 Gy. The median number of administered doses of rituximab (375 mg/m²) IV was four. All ten patients evaluated responded to treatment (100%). Median OS was 2.5 years with a 2-year Kaplan-Meier estimate of 63% (95% confidence interval 30-83%) without any recorded relapses after a median follow-up of 2.6 years. Seven of fourteen patients (50%) suffered grade III/IV infections under therapy (fatal in two cases, 14%). During follow-up, imaging demonstrated grey matter changes interpreted as radiation toxicity in 7/10 evaluated patients (70%). The combination of RI, WBRT, and rituximab was an effective yet toxic treatment of pCNS-PTLD in this series of 14 patients. Future treatment approaches in pCNS-PTLD should take into account the significant risk of infections as well as radiation-induced neurotoxicity.

Spontaneous regression of central nervous system posttransplant lymphoproliferative disease: A case report

RATIONALE

Primary central nervous system (CNS) posttransplant lymphoproliferative disease (PTLD) is a very rare entity. Patients may respond to reduction of immunosuppression or other therapies, but the prognosis is still pessimistic.

PATIENT CONCERNS

Herein, we report a 40-year-old female with a history of renal transplantation developed brain masses 4 years ago. Although brain biopsy was performed, PTLD was underdiagnosed then. No relevant treatment was administered. However, the lesions resolved spontaneously. After 4 years, new lesion appeared in a different brain region.

DIAGNOSES

The history of renal transplantation raised the suspicion of PTLD. Reexamination of previous brain sections confirmed the diagnosis of polymorphic PTLD (P-PTLD). A second biopsy of the new lesion also demonstrated P-PTLD.

INTERVENTIONS

She was referred to hematology department to receive rituximab.

OUTCOMES

After 4 rounds of treatment, the lesion resolved satisfactorily.

LESSONS

This case demonstrates the natural history of primary CNS P-PTLD. Although self-remission and recurrence is possible, aggressive measures should be taken to this condition.

CNS Post-Transplant Lymphoproliferative Disorder in a Heart Recipient: A Case Report

Solid organ recipients have increased risk of malignancy in comparison with general population. Although post-transplant lymphoproliferative disorders are the second most common cancer in transplanted patients, primary CNS lymphoma is a rare presentation of these disorders. Among the wide range of neurologic complications in post- transplant period, some characteristics could be helpful for diagnosing of this disorder. Rarity of CNS lymphoma may lead to late diagnosis of this disease while early detection has utmost importance for better management of it. Here, we describe a heart recipient young woman with focal neurologic symptoms 14 months after transplantation and some features that could be helpful for on-time diagnosis.

Central Nervous System Involvement in Epstein-Barr Virus-Related Post-Transplant Lymphoproliferative Disorders after Allogeneic Hematopoietic Stem Cell Transplantation

Central nervous system (CNS) involvement in Epstein-Barr virus-related post-transplant lymphoproliferative disorders (EBV-PTLDs) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is poorly defined. We analyzed the incidence, clinical and pathological characteristics, and impact on outcomes of EBV-PTLDs with CNS involvement (CNS-PTLDs) in 1009 consecutive adult patients undergoing allo-HSCT at a single-center institution. Four hundred eighty-two patients received matched sibling donor (MSD) transplants, 388 umbilical cord blood transplants (UCBTs), 56 matched unrelated donor (MUD) transplants, and 83 haploidentical transplants. We detected 25 cases of biopsy-proven EBV-PTLDs. Of these, nine patients (36%) had CNS-PTLDs: six after UCBT (67%), one after MSD transplantation (11%), one after MUD transplantation (11%), and one after haploidentical transplantation (11%). The 5-year cumulative incidence risk of CNS-PTLDs was 0.9%. Median time from transplant to CNS-PTLDs was 187 days, and all patients had neurological symptoms at diagnosis. Six out of the nine cases (67%) occurred with systemic involvement, and three cases (33%) had isolated CNS involvement. The most frequent histological subtype was monomorphic EBV-PTLD, and laboratory characteristics were similar to EBV-PTLDs without CNS involvement. We observed statistical differences in the rate of positive EBV DNA detection in plasma between isolated CNS-PTLDs (detection in one out of three, 33%) and the rest of the EBV-PTLDs (100%) (P = .01). Treatment strategies included chemotherapy, radiotherapy, and T cell therapy. However, seven out of nine patients died due to progression of the CNS-PTLDs at a median time of 17 days (range, 8 to 163) from diagnosis. The 5-years overall survival in patients who developed CNS-PTLDs was 22% (95% confidence interval [CI], 7% to 75%) and 5-year treatment-related mortality was 78% (95% CI, 51% to 100%), with no statistically significant differences between CNS-PTLDs and the rest of the EBV-PTLDs. In conclusion, despite advances in EBV monitoring and treatment strategies, CNS-PTLDs remain an uncommon but serious complication after allo-HSCT, with very poor prognosis.

Management of PTLD After Hematopoietic Stem Cell Transplantation: Immunological Perspectives

Post-transplant lymphoproliferative disorders (PTLDs) are life-threatening complications of iatrogenic immune impairment after allogeneic hematopoietic stem cell transplantation (HSCT). In the pediatric setting, the majority of PTLDs are related to the Epstein-Barr virus (EBV) infection, and present as B-cell lymphoproliferations. Although considered rare events, PTLDs have been increasingly observed with the widening application of HSCT from alternative sources, including cord blood and HLA-haploidentical stem cell grafts, and the use of novel agents for the prevention and treatment of rejection and graft-vs.-host disease. The higher frequency initially paralleled a poor outcome, due to limited therapeutic options, and scarcity of controlled trials in a rare disease context. In the last 2 decades, insight into the relationship between EBV and the immune system, and advances in early diagnosis, monitoring and treatment have changed the approach to the management of PTLDs after HSCT, and significantly ameliorated the prognosis. In this review, we summarize literature on the impact of combined viro-immunologic assessment on PTLD management, describe the various strategies for PTLD prevention and preemptive/curative treatment, and discuss the potential of novel immune-based therapies in the containment of this malignant complication.