Lymphoproliferative disorders after solid organ transplantation-classification, incidence, risk factors, early detection and treatment options

Isolated Muscular NK/T Cell Lymphoma: A Rare Presentation of Post-Transplant Lymphoproliferative Disorders

Posttransplant lymphoproliferative disorders (PTLDs) represent a spectrum of malignancies occurring in transplant recipients under immunosuppression, often linked with Epstein-Barr Virus infection. PTLD has a varied presentation, and isolated muscular involvement is infrequent. Here, we present the case of a 47-year-old female renal transplant recipient presenting with acute left knee joint swelling, initially suggestive of an infective or inflammatory etiology. Biopsy revealed high-grade non-Hodgkin lymphoma of natural killer/T-cell lymphoma. F-18 Fluorodeoxyglucose positron emission tomography-computed tomography scan revealed metabolically active soft tissue mass lesions isolated to thigh muscles. The patient was on a modified chemotherapy regimen tailored to accommodate renal function. This case underscores the necessity for heightened vigilance in diagnosing PTLD, particularly considering its atypical presentations.

Dynamic Presentations of Recurrent Post-Transplant Lymphoproliferative Disorder in a Heart Transplant Recipient: A Rare Case Study

Post-transplant lymphoproliferative disorders (PTLD) are complications that arise from post-transplantation immunosuppressive therapy. Although Epstein-Barr virus (EBV) viremia is often seen in PTLD, it is not a definitive feature for diagnosis. We report a rare case of recurrent PTLD in a 26-year-old heart transplant recipient on high-dose tacrolimus who presented with emesis, fatigue, and bloody diarrhea. Although substantial EBV viremia was seen in the first PTLD episode, the current episode was a gastrointestinal manifestation with barely detectable circulating EBV. The patient's history of gastrointestinal disease delayed definitive diagnosis, which was later established through endoscopy and biopsy sample analysis.

Mechanistic Understanding of EBV+Lymphoproliferative Disease Development After Transplantation

Posttransplant lymphoproliferative disorders (PTLDs) are among the most common malignant complications after transplantation, leading to a drastic reduction in patient survival rates. The majority of PTLDs are tightly linked to Epstein-Barr virus (EBV+PTLDs) and are the result of an uncontrolled proliferation of EBV-infected cells. However, although EBV infections are a common finding in transplant recipients, most patients with high EBV loads will never develop EBV+PTLD. Natural killer cells and EBV-specific CD8+ T lymphocytes are critical for controlling EBV-infected cells, and the impairment of these cytotoxic immune responses facilitates the unfettered proliferation of EBV-infected cells. Recent years have seen a considerable increase in available literature aiming to describe novel risk factors associated with the development of EBV+PTLD, which may critically relate to the strength of EBV-specific natural killer cell and EBV-CD8+ T lymphocyte responses. The accumulation of risk factors and the increased risk of developing EBV+PTLD go hand in hand. On the one hand, most of these risk factors, such as the level of immunosuppression or the EBV donor and recipient serologic mismatch, and distinct genetic risk factors are host related and affect cytotoxic EBV-specific immune responses. On the other hand, there is growing evidence that distinct EBV variants may have an increased malignant potential and are thus more likely to induce EBV+PTLD. Here, we aim to review, from a mechanistic point of view, the risk factors for EBV+PTLD in the host and the infecting EBV variants that may explain why only a minority of transplant recipients develop EBV+PTLD.

Management of long-term complications from immunosuppression

This review discusses long-term complications from immunosuppressants after liver transplantation and the management of these complications. Common complications of calcineurin inhibitors include nephrotoxicity and metabolic diseases. Nephrotoxicity can be managed by targeting a lower drug level and/or adding an immunosuppressant of a different class. Metabolic disorders can be managed by treating the underlying condition and targeting a lower drug level. Gastrointestinal adverse effects and myelosuppression are common complications of antimetabolites that are initially managed with dose reduction or discontinuation if adverse events persist. Mammalian targets of rapamycin inhibitors are associated with myelosuppression, proteinuria, impaired wound healing, and stomatitis, which may require dose reduction or discontinuation. Induction agents and agents used for steroid-refractory rejection or antibody-mediated rejection are reviewed. Other rare complications of immunosuppressants are discussed as well.

Changes in the gut microbiome can predict and decrease Epstein-Barr virus infection risk in children after liver transplantation

OBJECTIVE

Primary Epstein-Barr virus (EBV) infection is observed in 60% of children during the first year after liver transplantation as usage of imm-unosuppressant. Finding predictive indicators of EBV infection is important to reduce the morbidity and mortality of EBV infection-related diseases by suggesting a dose reduction of immunosuppressant.

METHODS

We compared and analysed the gut microbiome of EBV-infected children with an asymptomatic virus-carrying status and EBV-uninfected children after liver transplantation using high-throughput sequencing.

RESULTS

Significant differences in gut microbiome composition in two groups were detected. In detail, Firmicutes and Lactobacillus were increased in EBV-infected group, while Clostridium was increased in EBV-uninfected group. Furthermore, CD4 percentage in T cells of blood showed a significant positive correlation with the content of Clostridium sp. CAG: 127 in EBV-uninfected group.

CONCLUSION

Changes in the gut microbiome could predict and decrease the EBV infection risk of children after liver transplantation.

Epstein-Barr Virus-Associated Lymphomatoid Papules: A Sign of Immunosuppression Resembling Lymphomatoid Papulosis

ABSTRACT

Epstein-Barr virus (EBV)-positive lymphoproliferative disorders associated with immunodeficiency constitute a spectrum of lymphoid and plasma cell proliferations that vary in cytomorphology, immunophenotype, and clinical behavior. CD30-positive cutaneous lymphocytic infiltrates with EBV expression and lymphomatoid papulosis-like presentations have been rarely reported. This retrospective study assessed the clinical and histopathological characteristics of EBV-positive cases with papulonodular morphologies and CD30 positivity seen by Northwestern Medicine Dermatopathology. Twelve patients (7M:5F, mean age 69 years) were presented with papular cutaneous lesions without antecedent patch/plaque disease. Nine cases were associated with known immunosuppression in the setting of transplant-related therapies (n = 4), hematopoietic malignancy (n = 2), post-transplant hematopoietic malignancy (n = 1), and autoimmune disease treatment (n = 2). Two patients had age-related immunosenescence. Four patients demonstrated EBV viremia; for 2 patients, this finding comprised the first sign of immunosuppression. Workup was negative for systemic lymphoma in all patients. Various treatment strategies were used, including observation (n = 3), discontinuation/reduction of immunosuppression (n = 3), rituximab (n = 4), and steroids (n = 4). At mean 30-month follow-up, 4 patients (33.3%) were alive, 3 with and 1 without disease. Eight patients (67.6%) had died, 3 after lesional resolution and 5 with recurrent disease. Biopsies revealed mixed lymphoid infiltrates composed of atypical CD30-positive T cells (n = 5) or B cells (n = 7) with variable EBV-encoded small RNA expression. These cases suggest clinicopathologic presentations resembling lymphomatoid papulosis with atypical, large CD30-positive, EBV-positive cells could comprise first sign of potentially serious immunodeficiency and should prompt evaluation for EBV viremia. These cases also broaden the current picture of immunodeficiency-associated lymphoproliferative disorders to include lymphomatoid papulosis-like clinical presentations.

Post-transplant lymphoproliferative disorders (PTLD) in adolescents and young adults: A category in need of definition

Post-transplant lymphoproliferative disorders are a well-recognized complication of solid organ and stem cell transplantation. Much data has accumulated with respect to the pathobiology and clinical behavior of these lesions in the general post-transplant population as well as in the pediatric and adult age groups. However, information as to these lesions in the adolescent and young adult populations, which bridge the pediatric and adult groups, is limited. In this review, the focus is on this unique population of PTLD patients and their proliferations.

Posttransplant lymphoproliferative disorder in a heart transplant recipient: a case report

Malignancy in heart transplant recipients is a grave complication. Post-transplant lymphoproliferative disorder (PTLD) is the second most common tumour in adults and commonest in children. The incidence varies with the transplanted organ from 1 to 2% following kidney transplantation to as high as 10% following thoracic organ transplantation due to different immunosuppression intensity. PTLD include a wide spectrum of diseases ranging from benign proliferation of lymphoid tissue to frank malignancy with aggressive behaviour (lymphoma). Epstein-Barr virus (EBV) infection and prolonged immunosuppressant therapy are implicated in the pathogenesis of PTLD. The incidence of PTLD varies from 2.6% at 1 year to 28% at 10 years post-transplant. Seronegativity for EBV in recipients with seropositive donors increases the risk of PTLD in recipients. The majority of early-onset PTLDs (85%) are of B-cell origin and associated with EBV. Timely and accurate diagnosis with histological examination of lymphoid tissue is essential for early intervention. Reduction of immunosuppressive therapy (IST) and rituximab usually are effective in remission of PTLD. In resistant cases, chemotherapy is given with or without rituximab. Adoptive T-cell transfer represents a promising therapeutic approach. Early PTLD respond well to lowering immunosuppression and has a favourable prognosis compared to late PTLD. Five-year survival is 30% for high-grade lymphomas. The prognosis of EBV-negative lymphomas is worse. One out of 40 heart transplant recipients followed up in our centre developed PTLD. He was treated to remission and we describe this case here.

Lymphoproliferative disorders after renal transplantation along 2 decades: a large longitudinal study of 21.546 recipients

INTRODUCTION

Post transplant lymphoproliferative disorders (PTLD) are heterogeneous lymphoid proliferations in recipients of solid organs which seem to be related to Epstein Barr Virus (EBV). The use of antilymphocyte antibodies, EBV seronegativity in the recipient,acute rejection and CMV infection have been identified as classical risk factors.

MATERIAL Y METHODS

We have studied in a retrospective observational study, the incidence of PTLD in a period of 22 years, its relationship with EBV, presence of classical risk factors and outcome in 21546 simple adult renal transplant recipients from cadaveric and living donors, transplanted in 21 hospitals from 1990 to 2009.

RESULTS

A total of 275 recipients developed PTLD (1,2%),195 males (70,9%), 80 females (29,1%) aged 59.2 (p25 44.7 p75 68)years. Two hundred forty-five (89.0%) were 1st transplant recipients and 269 (97,8%) from cadaveric donors. EBV in the tissue was reported in 94 out of the 155 studied recipients (60.6%) and 86.0% of the proliferations were due to B lymphocytes. PTLD median appearance after transplant were 42.months (p25, 75, 12, 77, 5). One hundred eighty-eight recipients out of 275 patients (68.3%) had any classical risk factor and the use of antilymphocyte antibodies was the most frequent. During the follow-up, 172 patients died (62,5%) and 103 (37,5%) had a complete remission. The main cause of death was PTLD progression (n = 91, 52,9%), followed by sepsis (n = 24, 13,9%). The follow-up period post-transplant of the recipients was between 3 and 22 years. The incidence was 0,14% during the first year post-trasplant and 0.98% the cumulative incidence at 10 years. Patient survival after diagnosis was 51%, 44% and 39% after 1, 2 and 5 years, respectively. Finally, overall graft survival was 48%, 39% and 33% at the same periods.

CONCLUSION

PTLD has a low incidence in renal transplant recipients. Most of the proliferations are due to B lymphocytes and seem to have a close relationship with EBV. PTLD can develop in the absence of classical risk factors. The prognosis is poor, mainly due to PTLD progression, but the survivors can even maintain their grafts.

Post-transplant Lymphoproliferative Disorder (PTLD) in the US Population: Demographics, Treatment Characteristics, and Survival Analysis

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is a lymphoplasmacytic proliferative disorder in the setting of hematopoietic stem cells and solid organ transplants. PTLD is divided into nondestructive, polymorphic, monomorphic, and classical Hodgkin lymphoma subtypes. Most cases of PTLDs are Epstein-Barr virus (EBV) related (two third of the cases), and most are of B cell (80-85%) origin. The polymorphic PTLD subtype can be locally destructive and show malignant features. Treatment for PTLD includes a reduction in immunosuppression, surgery, cytotoxic chemotherapy and/or immunotherapy, anti-viral agents, and/or radiation. The aim of this study was to examine the demographic factors and treatment modalities that influence survival in patients with polymorphic PTLD.

METHODS

About 332 cases of polymorphic PTLD were identified from 2000 to 2018 using the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

The median age of the patients was found to be 44 years. The most common age groups were between the ages of 1-19 years (n=100. 30.1%) and 60-69 years (n=70. 21.1%). The majority of cases in this cohort underwent systemic (cytotoxic chemo and/or immuno) therapy only (n=137, 41.3%), while 129 (38.9%) cases did not undergo any treatment. The overall five-year observed survival was 54.6% (95% confidence interval (CI), 51.1 - 58.1). One-year and five-year survival with systemic therapy was 63.8% (95% CI, 59.6 - 68.0) and 52.5% (95% CI, 47.7 - 57.3), respectively. The one-year and five-year survival with surgery was 87.3% (95% CI, 81.2-93.4) and 60.8% (95% CI., 42.2 - 79.4), respectively. The one-year and five-year without therapy were 67.6% (95% CI, 63.2-72.0) and 49.6% (95% CI, 43.5-55.7), respectively. Univariate analysis revealed that surgery alone (hazard ratio (HR) 0.386 (0.170-0.879), p = 0.023) was a positive predictor of survival. Race and sex were not predictors of survival, although age >55 years was a negative predictor for survival (HR 1.128 (1.139-1.346), p <0.001).

CONCLUSION

Polymorphic PTLD is a destructive complication of organ transplantation that is usually associated with EBV positivity. We found that it most often presents in the pediatric age group, and its occurrence in those older than 55 years was associated with a worse prognosis. Treatment with surgery alone is associated with improved outcomes and should be considered in addition to a reduction in immunosuppression in cases of polymorphic PTLD.

Risk factors for Epstein-Barr virus reactivation after renal transplantation: Results of a large, multi-centre study

Epstein-Barr virus (EBV) reactivation is a very common and potentially lethal complication of renal transplantation. However, its risk factors and effects on transplant outcome are not well known. Here, we have analysed a large, multi-centre cohort (N = 512) in which 18.4% of the patients experienced EBV reactivation during the first post-transplant year. The patients were characterized pre-transplant and two weeks post-transplant by a multi-level biomarker panel. EBV reactivation was episodic for most patients, only 12 patients showed prolonged viraemia for over four months. Pre-transplant EBV shedding and male sex were associated with significantly increased incidence of post-transplant EBV reactivation. Importantly, we also identified a significant association of post-transplant EBV with acute rejection and with decreased haemoglobin levels. No further severe complications associated with EBV, either episodic or chronic, could be detected. Our data suggest that despite relatively frequent EBV reactivation, it had no association with serious complications during the first post-transplantation year. EBV shedding prior to transplantation could be employed as biomarkers for personalized immunosuppressive therapy. In summary, our results support the employed immunosuppressive regimes as relatively safe with regard to EBV. However, long-term studies are paramount to support these conclusions.

Post-transplant primary cutaneous peripheral T-cell lymphoma not otherwise specified in a pediatric patient

Solid organ and hematopoietic stem cell transplantation may be complicated by the development of post-transplant lymphoproliferative disorders (PTLDs). The World Health Organization categorizes PTLDs into four entities including non-destructive, monomorphic, polymorphic, and classical Hodgkin lymphoma types. The most common PTLDs are B-cell lymphomas, with T-cell lymphomas accounting for only a few cases. Cutaneous T-cell lymphomas are rarer still in post-transplant patients with primary cutaneous peripheral T-cell lymphoma being an extraordinarily rare subtype in this population. PTLDs may be aggressive and are often associated with high morbidity and mortality. Advances in medicine have led to increased awareness of PTLDs and improved diagnostic tools which assist in the diagnosis of these conditions. However, the clinical and histopathologic heterogeneity of PTLDs may make diagnosis a challenge. In the transplant patient population, the cutaneous manifestations of the lymphoproliferative disease may mimic other conditions, such as eczematous dermatitis and graft-vs-host disease. Herein, we report a case of post-transplant primary cutaneous peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) in a pediatric heart transplant patient and describe the clinical presentation and diagnostic histopathologic features.

The role of soluble mediators in the clinical course of EBV infection and B cell homeostasis after kidney transplantation

Epstein-Barr virus (EBV) reactivation can lead to serious complications in kidney transplant patients, including post-transplant lymphoproliferative disorder (PTLD). Here, we have assessed the impact of EBV on B cell homeostasis at cellular and humoral level. In a multicenter study monitoring 540 kidney transplant patients during the first post-transplant year, EBV reactivation was detected in 109 patients. Thirteen soluble factors and B cell counts were analyzed in an EBV+ sub-cohort (N = 54) before, at peak and after EBV clearance and compared to a control group (N = 50). The B cell activating factor (BAFF) was significantly elevated among EBV+ patients. No additional soluble factors were associated with EBV. Importantly, in vitro experiments confirmed the proliferative effect of BAFF on EBV-infected B cells, simultaneously promoting EBV production. In contrast, elevated levels of BAFF in EBV+ patients did not lead to B cell expansion in vivo. Moreover, diminished positive inter-correlations of soluble factors and alterations of the bi-directional interplay between B cell and soluble factors were observed in EBV+ patients at peak and after clearance. Our data suggest that such alterations may counteract the proliferative effect of BAFF, preventing B cell expansion. The role of these alterations in lymphoma development should be analyzed in future studies.

Hematologic malignancies of the gastrointestinal luminal tract

Hematologic malignancies include several lymphoproliferative and myeloproliferative disorders, many of which are frequently encountered in current health care settings. These malignancies frequently affect the gastrointestinal (GI) tract, either by secondary extranodal or extramedullary extension to the GI tract, or as a primary process arising in the GI tract. In fact, the GI tract may represent the most common extranodal site of involvement in many of them, such as lymphoma. Furthermore, in the current era of improved cancer treatment and advanced transplant procedures with increased survival, it has been quite common to encounter GI involvement by these malignancies through the disease course. Post-transplant lymphoproliferative disorder following kidney transplantation, for example, very commonly involves the GI tract. Other conditions that can involve the GI tract include multiple myeloma, plasmacytoma, myeloid sarcoma, mastocytosis, and Castleman disease. Imaging diagnosis of these malignancies can be challenging, since they are much less common than primary GI cancers and both share many common imaging features as well. However, certain imaging features, particularly in combination with a matching clinical scenario, play a pivotal role in diagnosing these conditions and directing further evaluation. In this article, we review common and rare hematologic malignancies of the GI tract and discuss their pathophysiologic, clinical, and imaging features.

Signaling pathways involved in the T-cell-mediated immunity against Epstein-Barr virus: Lessons from genetic diseases

Primary immunodeficiencies (PIDs) provide researchers with unique models to understand in vivo immune responses in general and immunity to infections in particular. In humans, impaired immune control of Epstein-Barr virus (EBV) infection is associated with the occurrence of several different immunopathologic conditions; these include non-malignant and malignant B-cell lymphoproliferative disorders, hemophagocytic lymphohistiocytosis (HLH), a severe inflammatory condition, and a chronic acute EBV infection of T cells. Studies of PIDs associated with a predisposition to develop severe, chronic EBV infections have led to the identification of key components of immunity to EBV - notably the central role of T-cell expansion and its regulation in the pathophysiology of EBV-associated diseases. On one hand, the defective expansion of EBV-specific CD8 T cells results from mutations in genes involved in T-cell activation (such as RASGRP1, MAGT1, and ITK), DNA metabolism (CTPS1) or co-stimulatory pathways (CD70, CD27, and TNFSFR9 (also known as CD137/4-1BB)) leads to impaired elimination of proliferating EBV-infected B cells and the occurrence of lymphoma. On the other hand, protracted T-cell expansion and activation after the defective killing of EBV-infected B cells is caused by genetic defects in the components of the lytic granule exocytosis pathway or in the small adapter protein SH2D1A (also known as SAP), a key activator of T- and NK cell-cytotoxicity. In this setting, the persistence of EBV-infected cells results in HLH, a condition characterized by unleashed T-cell and macrophage activation. Moreover, genetic defects causing selective vulnerability to EBV infection have highlighted the role of co-receptor molecules (CD27, CD137, and SLAM-R) selectively involved in immune responses against infected B cells via specific T-B cell interactions.

18F-FDG PET/CT in the Diagnostic and Treatment Evaluation of Pediatric Posttransplant Lymphoproliferative Disorders

We aimed to evaluate the diagnostic performance of ¹⁸F-FDG PET/CT for the detection of posttransplantation lymphoproliferative disorder (PTLD) in a pediatric population and explore its feasibility during response assessment. Methods: This retrospective study included 28 pediatric transplant recipients who underwent a total of 32 ¹⁸F-FDG PET/CT scans due to clinical suspicion of PTLD within an 8-y period. Pathology reports and 2 y of follow-up were used as the reference standard. Twenty-one response assessment ¹⁸F-FDG PET/CT scans were reevaluated according to the Lugano criteria. Results: The diagnosis of PTLD was established in 14 patients (49%). Sensitivity, specificity, positive predictive value, and negative predictive value of ¹⁸F-FDG PET/CT for the detection of PTLD in children with a clinical suspicion of this disease were 50% (7/14), 100% (18/18), 100% (7/7), and 72% (18/25), respectively. False-negative results occurred in patients with PTLD in the Waldeyer's ring, cervical lymph nodes, or small bowel with either nondestructive or polymorphic PTLD. Two of 5 interim ¹⁸F-FDG PET/CT scans and 3 of 9 end-of-treatment ¹⁸F-FDG PET/CT scans were false-positive. Conclusion: ¹⁸F-FDG PET/CT had good specificity and positive predictive value but low to moderate sensitivity and negative predictive value for the detection of PTLD in a 28-pediatric-patient cohort with a clinical suspicion of this disease. False-negative results were confirmed in the Waldeyer's ring, cervical lymph nodes, and small bowel with either nondestructive or polymorphic PTLD subtypes. ¹⁸F-FDG PET/CT appears to have a limited role in the response assessment setting of pediatric PTLD, given the observed high proportions of false-positives both at interim and at end-of-treatment evaluations.

Diagnostic performance of FDG-PET/CT of post-transplant lymphoproliferative disorder and factors affecting diagnostic yield

Purpose

Post-transplant lymphoproliferative disorder (PTLD) is a serious complication after solid organ and hematopoietic stem cell transplantation, requiring a timely and accurate diagnosis. In this study, we evaluated the diagnostic performance of FDG-PET/CT in patients with suspected PTLD and examined if lactate dehydrogenase (LDH) levels, Epstein-Barr virus (EBV) load, or timing of FDG-PET/CT relate to detection performance of FDG-PET/CT.

Methods

This retrospective study included 91 consecutive patients with clinical suspicion of PTLD and a total of 97 FDG-PET/CT scans within an 8-year period. Pathology reports and a 2-year follow-up were used as the reference standard. Diagnostic performance of FDG-PET/CT for detection of PTLD as well as logistic regression analysis for factors expected to affect diagnostic yield were assessed.

Results

The diagnosis of PTLD was established in 34 patients (35%). Fifty-seven FDG-PET/CT scans (59%) were true negative, 29 (30%) were true positive, 6 (6%) false positive, and 5 (5%) false negative. Sensitivity of FDG-PET/CT for the detection of PTLD was 85%, specificity 90%, positive predictive value 83%, and negative predictive value 92%, with good inter-observer variability (k = 0.78). Of the parameters hypothesized to be associated with a true positive FDG-PET/CT result for the diagnosis of PTLD, only LDH was statistically significant (OR 1.03, p = 0.04).

Conclusion

FDG-PET/CT has a good diagnostic performance in patients suspected of PTLD, with a good inter-observer agreement. Only LDH levels seemed to influence the detection performance of FDG-PET/CT. EBV-DNA load and timing of FDG-PET/CT after transplantation did not affect FDG-PET/CT diagnostic yield.

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

BACKGROUND/AIMS

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

BKV, CMV, and EBV Interactions and their Effect on Graft Function One Year Post-Renal Transplantation: Results from a Large Multi-Centre Study

Background

BK virus (BKV), Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) reactivations are common after kidney transplantation and associated with increased morbidity and mortality. Although CMV might be a risk factor for BKV and EBV, the effects of combined reactivations remain unknown. The purpose of this study is to ascertain the interaction and effects on graft function of these reactivations.

Methods

3715 serum samples from 540 kidney transplant recipients were analysed for viral load by qPCR. Measurements were performed throughout eight visits during the first post-transplantation year. Clinical characteristics, including graft function (GFR), were collected in parallel.

Findings

BKV had the highest prevalence and viral loads. BKV or CMV viral loads over 10,000 copies·mL⁻¹ led to significant GFR impairment. 57 patients had BKV-CMV combined reactivation, both reactivations were significantly associated (p = 0.005). Combined reactivation was associated with a significant GFR reduction one year post-transplantation of 11.7 mL·min⁻¹·1.73 m⁻² (p = 0.02) at relatively low thresholds (BKV > 1000 and CMV > 4000 copies·mL⁻¹). For EBV, a significant association was found with CMV reactivation (p = 0.02), but no GFR reduction was found. Long cold ischaemia times were a further risk factor for high CMV load.

Interpretation

BKV-CMV combined reactivation has a deep impact on renal function one year post-transplantation and therefore most likely on long-term allograft function, even at low viral loads. Frequent viral monitoring and subsequent interventions for low BKV and/or CMV viraemia levels and/or long cold ischaemia time are recommended.

Fund

Investigator Initiated Trial; financial support by German Federal Ministry of Education and Research (BMBF).

Multimodality imaging features, treatment, and prognosis of post-transplant lymphoproliferative disorder in renal allografts: A case report and literature review

RATIONALE

Among patients with post-transplant lymphoproliferative disorder (PTLD), there is a high incidence of immunosuppressed transplant recipients. It is necessary to make an early diagnosis to increase the likelihood of a good prognosis.

PATIENT CONCERNS

We report a case of a 54-year-old female patient who developed PTLD after liver and kidney transplantation.

DIAGNOSES

We aimed to analyze the standard diagnosis and follow-up of PTLD with imaging. Radiologists need to be familiar with all imaging modalities when dealing with PTLD, including ultrasonography, computed tomography, magnetic resonance imaging, positron-emission tomography/computed tomography.

INTERVENTIONS

The initial treatment included both reduction of immunosuppression and rituximab. Then the treatment strategy changed to rituximab and chemotherapy. Finally, the treatment strategy combined glucocorticoid therapy.

OUTCOMES

The patient was in a stable condition at the 3-month follow-up.

LESSONS

Systematic evaluation of the various imaging modalities, treatment options, and prognoses of PTLD in renal allografts suggested that in cases with a poor prognosis, the proper imaging modalities provide essential information with regard to the determination of the appropriate treatment.

Epstein-Barr virus DNA monitoring in serum and whole blood in pediatric liver transplant recipients who do or do not discontinue immunosuppressive therapy

The rate of PTLD can be reduced by weaned IS guided by monitoring of EBV DNA. In this single-center retrospective case series study, we analyzed how reduction in IS influenced EBV DNA levels in whole blood and serum in 30 children during the first year after liver transplantation, and how these levels were related to symptoms putatively due to EBV. Primary and reactivated EBV infection was seen in 18 (60%) and eight patients (27%), respectively. Thirteen patients (42%) developed chronic high load the first year post-transplant. IS was successfully discontinued in six patients the first year post-transplant and in another two patients within 3 years. EBV DNA levels were reduced, but persisted long term in all the eight patients who had IS completely withdrawn. There was no case of PTLD. In summary, EBV DNAemia and chronic high load were very common after pediatric liver transplantation. Liver graft tolerance facilitates radical reduction in IS treatment, which may prevent PTLD, but EBV DNAemia may persist long term after discontinued IS.

Three Hypothetical Inflammation Pathobiology Phenotypes and Pediatric Sepsis-Induced Multiple Organ Failure Outcome

OBJECTIVES

We hypothesize that three inflammation pathobiology phenotypes are associated with increased inflammation, proclivity to develop features of macrophage activation syndrome, and multiple organ failure-related death in pediatric severe sepsis.

DESIGN

Prospective cohort study comparing children with severe sepsis and any of three phenotypes: 1) immunoparalysis-associated multiple organ failure (whole blood ex vivo tumor necrosis factor response to endotoxin < 200 pg/mL), 2) thrombocytopenia-associated multiple organ failure (new onset thrombocytopenia with acute kidney injury and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 activity < 57%), and/or 3) sequential multiple organ failure with hepatobiliary dysfunction (respiratory distress followed by liver dysfunction with soluble Fas ligand > 200 pg/mL), to those without any of these phenotypes.

SETTING

Tertiary children's hospital PICU.

PATIENTS

One hundred consecutive severe sepsis admissions.

INTERVENTIONS

Clinical data were recorded daily, and blood was collected twice weekly.

MEASUREMENTS AND MAIN RESULTS

Multiple organ failure developed in 75 cases and eight died. Multiple organ failure cases with any of the three inflammation phenotypes (n = 37) had higher inflammation (C-reactive protein, p = 0.009 and ferritin, p < 0.001) than multiple organ failure cases without any of these phenotypes (n = 38) or cases with only single organ failure (n = 25). Development of features of macrophage activation syndrome and death were more common among multiple organ failure cases with any of the phenotypes (macrophage activation syndrome: 10/37, 27%; death: 8/37, 22%) compared to multiple organ failure cases without any phenotype (macrophage activation syndrome: 1/38, 3%; p = 0.003 and death: 0/38, 0%; p = 0.002).

CONCLUSIONS

Our approach to phenotype categorization remains hypothetical, and the phenotypes identified need to be confirmed in multicenter studies of pediatric multiple organ dysfunction syndrome.

Posttransplant Lymphoproliferative Disorder: Otolaryngological Manifestations and Management

Objective

Posttransplant lymphoproliferative disorder (PTLD) is a unifying term for a spectrum of lymphoid expansion entities brought about by immunosuppression and is strongly associated with Epstein-Barr virus (EBV). Otolaryngological findings tend to present early in the clinical course; therefore, disease awareness among otolaryngologists is of utmost importance. This review synthesizes the body of literature pertaining to PTLD involving the head and neck, summarizes contemporary management, and highlights areas for future research.

Data Sources

PubMed/Medline.

Review Methods

Primary literature search of the Medline database was performed for all titles published in the past 10 years pertaining to PTLD. The database search included PTLD combined with a collection of otolaryngological MeSH terms. Full manuscripts were reviewed based on relevance of their title and abstract. Selection into this review was according to clinical and scientific relevance.

Conclusion

Adenotonsillar focus is common in children in whom adenotonsillectomy may be diagnostic and prevents potentially morbid airway obstruction. Sinonasal PTLD may mimic fungal infection. Laryngotracheal involvement predominately presents in children with symptoms of airway obstruction. PTLD limited to the esophagus is rare. Oral PTLD is rare and phenotypically varied. Cutaneous presentation of PTLD is infrequent, yet one-third of cases affects the head and neck. PTLD may present as cervical lymphadenopathy.

Implications for Practice

PTLD consideration is vital when evaluating posttransplant patients. Children and EBV-seronegative patients should receive otolaryngological follow-up after transplant. PTLD treatment is multidisciplinary and typically led by lymphoma specialists. Formal partnerships between otolaryngologists and transplant centers may improve patient care and research quality.

Monomorphic Post-transplant Lymphoproliferative Disorder After Kidney Transplantation and Hematopoietic Stem Cell Transplantation: Clinicopathological Characteristics, Treatments and Prognostic Factors

Post-transplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid neoplasms associated with immunosuppression following transplantation. Among PTLDs, monomorphic PTLD (m-PTLD) is the largest category; however, its characteristics and survival outcome are not fully understood because of low incidence. This study enrolled 30 adult patients with m-PTLD after kidney-transplantation (KT, n = 17) and hematopoietic stem cell transplantation (HSCT, n = 13) from January 1998 to December 2014. The incidence rates of m-PTLD were 0.74 and 3.63% in the KT and HSCT groups, respectively. M-PTLD patients in the HSCT group were younger and showed earlier onset, with EBV-encoded small RNAs (EBER) more frequently identified. Diffuse large B cell lymphoma (DLBCL) was the main pathological type, and the digestive system was the most extranodal involvement site in m-PTLD after KT and HSCT. Among the 28 patients with DLBCL m-PTLD,the complete remission rate after rituximab treatment was higher than in patients not administered rituximab treatment (P = 0.038). With a median follow-up of 46 months after m-PTLD diagnosis, the estimated 5-year overall survival (OS) was 59.2 ± 9.1% in all patients, and 64.2 ± 11.8 and 52.7 ± 14.1% in the KT and HSCT groups, respectively (P = 0.741). ECOG PS, Ann Arbor stage, and CD68 IHC expression were independent prognostic factors for OS. M-PTLD is a rare but serious complication after transplantation. Ongoing efforts to standardize safe and effective treatment protocols would improve the poor overall survival. The independent prognostic factors contributed to risk-stratified treatment, and might be validated by larger studies.

T cell-rich lymphoid infiltrates with large B cells: a review of key entities and diagnostic approach

Accurate diagnostic interpretation of a lymphoid population composed predominantly of small T cells, together with smaller numbers of large B cells, with or without a nodular architecture, is a common problem faced by the histopathologist. The differential diagnosis of this histological pattern is wide, ranging from reactive conditions such as drug reactions and viral infections, through borderline entities such as immunodeficiency-related lymphoproliferative disorders to lymphomas. The latter includes entities where the large B cells are primarily neoplastic (classical and nodular lymphocyte-predominant Hodgkin lymphomas and T cell/histiocyte-rich large B cell lymphoma) as well as T cell lymphomas such as angioimmunoblastic T cell lymphoma where the large B cells represent an epiphenomenon and may or may not be neoplastic. Several rare variants of these conditions, and the fact that treatment can significantly modify appearances, add to the diagnostic difficulty of these pathological entities. Unlike monomorphic lymphoid infiltrates, the histological pattern of T cell-rich proliferation with large B cells requires close evaluation of the inter-relationship between B cells and T cells, follicular dendritic cells and sometimes other inflammatory cells. Epstein-Barr virus plays a key role in several of these scenarios, and interpreting not only its presence but also its distribution within cellular subgroups is essential to accurate diagnosis and the avoidance of some important diagnostic pitfalls. An understanding of normal immunoarchitecture and lymphoid maturational pathways is also fundamental to resolving these cases, as is a knowledge of their common patterns of spread, which facilitates correlation with clinical and radiological findings.

HLA and Risk of Diffuse Large B cell Lymphoma After Solid Organ Transplantation

BACKGROUND

Solid organ transplant recipients have heightened risk for diffuse large B cell lymphoma (DLBCL). The role of donor-recipient HLA mismatch and recipient HLA type on DLBCL risk are not well established.

METHODS

We examined 172 231 kidney, heart, pancreas, and lung recipients transplanted in the United States between 1987 and 2010, including 902 with DLBCL. Incidence rate ratios (IRRs) were calculated using Poisson regression for DLBCL risk in relation to HLA mismatch, types, and zygosity, adjusting for sex, age, race/ethnicity, year, organ, and transplant number.

RESULTS

Compared with recipients who had 2 HLA-DR mismatches, those with zero or 1 mismatch had reduced DLBCL risk, (zero: IRR, 0.76, 95% confidence interval [95% CI], 0.61-0.95; one: IRR, 0.83; 95% CI, 0.69-1.00). In stratified analyses, recipients matched at either HLA-A, -B, or -DR had a significantly reduced risk of late-onset (>2 years after transplantation), but not early-onset DLBCL, and there was a trend for decreasing risk with decreasing mismatch across all 3 loci (P = 0.0003). Several individual recipient HLA-A, -B, -C, -DR, and -DQ antigens were also associated with DLBCL risk, including DR13 (IRR, 0.74; 95% CI, 0.57-0.93) and B38 (IRR, 1.48; 95% CI, 1.10-1.93), confirming prior findings that these 2 antigens are associated with risk of infection-associated cancers.

CONCLUSIONS

In conclusion, variation in HLA is related to susceptibility to DLBCL, perhaps reflecting intensity of immunosuppression, control of Epstein-Barr virus infection among transplant recipients or chronic immune stimulation.

Matched-pair analysis: identification of factors with independent influence on the development of PTLD after kidney or liver transplantation

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) adversely affects patients' long-term outcome.

METHODS

The paired t test and McNemar's test were applied in a retrospective 1:1 matched-pair analysis including 36 patients with PTLD and 36 patients without PTLD after kidney or liver transplantation. Matching criteria were age, gender, indication, type of transplantation, and duration of follow-up. All investigated PTLD specimen were histologically positive for EBV. Risk-adjusted multivariable regression analysis was used to identify independence of risk factors for PTLD detected in matched-pair analysis. The resultant prognostic model was assessed with ROC-curve analysis.

RESULTS

Patients suffering with PTLD had shorter mean survival (p = 0.004), more episodes of CMV infections or reactivations (p = 0.042), and fewer recipient HLA A2 haplotypes (p = 0.007), a tacrolimus-based immunosuppressive regimen (p = 0.052) and higher dosages of tacrolimus at hospital discharge (Tac dosage) (p = 0.052). Significant independent risk factors for PTLD were recipient HLA A2 (OR = 0.07, 95 % CI = 0.01-0.55, p = 0.011), higher Tac dosages (OR = 1.29, 95 % CI = 1.01-1.64, p = 0.040), and higher numbers of graft rejection episodes (OR = 0.38, 95 % CI = 0.17-0.87, p = 0.023). The following prognostic model for the prediction of PTLD demonstrated good model fit and a large area under the ROC curve (0.823): PTLD probability in % = Exp(y)/(1 + Exp(y)) with y = 0.671 - 1.096 × HLA A2-positive recipient + 0.151 × Tac dosage - 0.805 × number of graft rejection episodes.

CONCLUSIONS

This study suggests prognostic relevance for recipient HLA A2, CMV, and EBV infections or reactivations and strong initial tacrolimus-based immunosuppression. Patients with risk factors may benefit from intensified screening for PTLD.

First-line use of rituximab correlates with increased overall survival in late post-transplant lymphoproliferative disorders: retrospective, single-centre study

This retrospective study evaluates the impact of rituximab on PTLD response and survival in a single-centre cohort. PTLD cases between 1984 and 2009, including heart, kidney, liver and lung transplant recipients, were included. Survival was analysed taking into account the type of PTLD (monomorphic vs. polymorphic), EBV infection status, IPI score, Ann Arbor stage and use of rituximab. Among 1335 transplanted patients, 24 developed PTLD. Median age was 54 yr (range 29-69), median time to diagnosis 50 months (range 0-100). PTLD type was predominantly late/monomorphic (79% and 75%), mostly diffuse large B-cell type. Overall response rate (ORR) was 62% (66% rituximab vs. 50% non-rituximab; P = 0.5). R-CHOP-like regimens were used most frequently (72% of patients treated with rituximab). Median overall survival was 64 months (CI 95% 31-96). OS was significantly increased in patients treated with rituximab (P = 0.01; CI 95% rituximab 58-79 months; non-rituximab 1-30 months). Post-transplant immunosuppression regimen had no effect on survival or time to PTLD, except for cyclosporine A (CyA), which associated with increased time to PTLD (P = 0.02). Rituximab was associated with increased survival in our single-centre series, and it should be considered as first-line therapy for PTLD patients. The possible protective effect of CyA for development of PTLD should be prospectively evaluated.

Prognostic performance of lymphocyte-to-monocyte ratio in diffuse large B-cell lymphoma: an updated meta-analysis of eleven reports

PURPOSE

The findings on the prognostic value of lymphocyte-to-monocyte ratio (LMR) in diffuse large B-cell lymphoma (DLBCL) are inconsistent. This meta-analysis was conducted to more precisely evaluate the prognostic significance of LMR in DLBCL.

METHODS

This analysis combined eleven studies with 4,578 patients aiming to assess the association of LMR with overall survival (OS) and progression-free survival (PFS) in DLBCL. Data from studies directly reporting a hazard ratio (HR) with 95% corresponding confidence interval (CI) in multivariate analysis were pooled to estimate the effect.

RESULTS

Our results suggested that patients with decreased LMR had shorter OS (HR =1.79, 95% CI =1.54-2.08, P<0.001) and PFS (HR =2.21, 95% CI =1.80-2.72, P<0.001) in DLBCL. Stratified analyses indicated that each confounder showed consistent prognostic value in DLBCL. There was no significant heterogeneity for PFS (P H=0.192) and OS (P H=0.212) among the enrolled studies.

CONCLUSION

This meta-analysis indicated that decreased LMR might be a marker in the prediction of poor prognosis for patients with DLBCL.

Prognostic significance of lymphocyte-to-monocyte ratio in diffuse large B-cell lymphoma: a systematic review and meta-analysis

Published evidence on the prognostic significance of lymphocyte-to-monocyte ratio (LMR) in diffuse large B-cell lymphoma (DLBCL) is controversial. We performed an updated meta-analysis from 12 reports with 5021 patients to more accurately evaluate the prognostic value of LMR in DLBCL. Herein, we confirmed that patients with low LMR had shorter overall survival and progression-free survival than those with high LMR in DLBCL. Subgroup analyses indicated that patient source, cut-off values of LMR, treatment methods, and sample size showed similar prognostic performance in DLBCL patients. No significant heterogeneity was observed for progression-free survival (PFS, P (het) = 0.192) among the enrolled studies. The meta-analysis suggests that the LMR may be a potential biomarker in the prediction of clinical outcomes for DLBCL patients.

Diagnosis and differential diagnosis of hepatic graft versus host disease (GVHD)

Graft versus host disease (GVHD) is a common complication following allogeneic hematopoietic cell transplantation (HCT) that typically manifests as injury to the skin, gastrointestinal mucosa, and liver. In some cases, hepatic GVHD may be histologically indistinguishable from other disorders such as infection and drug-induced liver injury (DILI). Additionally, clinical signs and symptoms are frequently confounded by the superimposed effects of pretransplant chemoradiotherapy, immunotherapy (IT) (targeted to the underlying malignancy), GVHD prophylaxis, and infection. Thus, careful attention to and correlation with clinical findings, laboratory values, and histologic features is essential for diagnosis. This review, aimed at the practicing pathologist, will discuss current clinical and histologic criteria for GVHD, the approach to diagnosis of hepatic GVHD, and features helpful for distinguishing it from other entities in the differential diagnosis.

Posttransplant lymphoproliferative disease and survival in adult heart transplant recipients

BACKGROUND

The influence of posttransplant lymphoproliferative disease (PTLD) on long-term survival after heart transplantation (HTx) in adult recipients needs better characterization.

METHODS

The United Network for Organ Sharing database was queried from 2006 to 2015 to compare survival between adult HTx recipients with and without PTLD. Cox proportional hazards models were used to analyze the primary outcome of survival, and competing-risks regression was used to analyze the outcome of PTLD development.

RESULTS

A total of 14,487 HTx recipients who had data on PTLD were included in univariate Cox analysis and Kaplan-Meier survival function, while 10,422 were included in multivariable Cox analysis and 162 selected for a matched-pairs sample after matching on the propensity of developing PTLD. The cohort included 120 patients who were diagnosed with PTLD. Onset of PTLD, treated as a time-varying covariate, was adversely associated with survival in univariate (HR=4.953; 95% CI: 3.768, 6.511; p<0.001) and multivariable (HR=3.849; 95% CI: 2.669, 5.552; p<0.001) Cox proportional hazards models. Cox regression stratified on matched pairs of PTLD cases and non-PTLD controls confirmed the risk for death associated with PTLD onset (HR=2.667; 95% CI: 1.043, 6.815; p=0.040).

CONCLUSIONS

PTLD onset negatively influenced survival in adult HTx recipients, whereas no characteristics predisposing patients to PTLD development were identified in multivariate analysis.

Post-transplant Lymphoproliferative Disorder: A Single-Center Experience

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is the second most common neoplasia after adult kidney transplantation (KT).

METHODS

We retrospectively analyzed 8 adult patients who underwent KT in our center, diagnosed with PTLD between 2001 and 2014.

RESULTS

Six patients were men. The median age at presentation was 43 years and the median time since transplantation was 7.3 years. Three patients had previously received anti-thymocyte globulin/OKT3, and all were taking calcineurin inhibitors (CNI) at diagnosis. The monomorphic type was the most common, with diffuse large B-cell lymphoma as the origin. The most frequent presentation was fever. Four in five patients had Epstein-Barr-related PTLD. All patients received various regimens of immunosuppression reduction (IR), with 4 converting CNI to mTOR inhibitor (imTOR). Subsequent treatment (when needed) was chemotherapy, radiotherapy, and surgery. The maximum follow-up time was 6.7 years, with a 50% mortality rate that occurred at a median time of 3.5 months (2 died with functioning kidney). All 4 patients who were in remission at the end of follow-up had CNI conversion to imTOR, and none lost the allograft.

CONCLUSIONS

Despite the small number of cases, our results confirm the high PTLD impact in overall and allograft survival. Our PTLD type distribution is in accord with the literature. First-line PTLD treatment is IR, but the best method is still unknown; our results may suggest a beneficial effect of CNI conversion to imTOR.

Posterior Reversible Encephalopathy Syndrome After Transplantation: a Review

Posterior reversible encephalopathy syndrome (PRES) is a rare neurological disease. Recently, an increase in the number of transplantations has led to more cases being associated with PRES than what was previously reported. Calcineurin inhibitors (CNIs) are major risk factors for PRES in posttransplantation patients. The mechanisms of the development of PRES remain to be unclear. The typical clinical symptoms of PRES include seizures, acute encephalopathy syndrome, and visual symptoms. The hyperintense signal on fluid-attenuated inversion recovery image is the characteristic of the imaging appearance in these patients. In addition, other abnormal signals distributed in multiple locations are also reported in some atypical cases. Unfortunately, PRES is often not recognized or diagnosed too late due to complicated differential diagnoses, such as ischemic stroke, progressive multifocal leukoencephalopathy, and neurodegenerative diseases. Thus, this review emphasizes the importance of considering the possibility of PRES when neurological disturbances appear after solid organ transplantation or hematopoietic cell transplantation. Moreover, this review demonstrates the molecular mechanisms of PRES associated with CNIs after transplantation, which aims to help clinicians further understand PRES in the transplantation era.

Influence of Posttransplant Lymphoproliferative Disorder on Survival in Children After Heart Transplantation

The influence of posttransplant lymphoproliferative disorder (PTLD) on long-term survival in children after heart transplantation (HTx) is not well studied. The United Network for Organ Sharing database was queried from 1987 to 2013 for data on PTLD in relation to induction immunosuppression and recipient Epstein-Barr virus status in children (<18 years of age) who underwent HTx. Of 6818 first-time pediatric heart transplants, 5169 had follow-up data on posttransplant malignancy, with 360 being diagnosed with PTLD. Univariate Cox analysis identified diminished survival after PTLD onset using a time-varying measure of PTLD (HR 2.208; 95 % CI 1.812, 2.689; p < 0.001), although Kaplan-Meier survival functions found no difference in survival between the group ever diagnosed with PTLD and the non-PTLD reference group (log-rank test: χ 1 (2)  = 0.02; p = 0.928). A multivariate Cox model found a greater mortality hazard associated with the development of PTLD after adjusting for recipient EBV seronegativity and other covariates (HR 3.024; 95 % CI 1.902, 4.808; p < 0.001). Induction immunosuppression at time of HTx did not significantly influence posttransplant mortality. The development of PTLD adversely influenced long-term survival in children after HTx after adjusting for confounding variables.

Treatment of Recurrent Posttransplant Lymphoproliferative Disorder with Autologous Blood Stem Cell Transplant

Background. Posttransplant lymphoproliferative disorders (PTLDs) occur after solid organ transplantation. Treatment guidelines include reduction in immunosuppression (RIS), radiation, rituximab, chemotherapy, and immunological agents. We present a rare case of recurrent diffuse large B-cell lymphoma presenting as a PTLD in a heart transplant patient treated with autologous blood stem cell transplant (ASCT) after failure of conventional therapy. Case Presentation. A 66-year-old male presented with a neck mass. He has a history of Hodgkin's disease status after staging laparotomy with splenectomy and heart transplantation due to dilated nonischemic cardiomyopathy 8 years prior to the development of PTLD. His examination was remarkable for right submandibular swelling. An excisional biopsy confirmed the diagnosis of diffuse large B-cell NHL. Patient received RIS, rituximab, chemotherapy, and radiation therapy with a complete remission. His lymphoma relapsed and he subsequently was treated with RICE salvage chemotherapy and consolidative high-dose chemotherapy with BEAC regimen followed by ASCT resulting in a complete remission. Conclusion. Patients with PTLD present a difficult therapeutic challenge. In this case, the patient's prior history of Hodgkin's disease, splenectomy, and a heart transplant appear to be unique features, the significance of which is unclear. ASCT might be a promising therapy for patients with relapsed or refractory PTLD.

Primary immunodeficiencies and the control of Epstein-Barr virus infection

Human primary immunodeficiency (PID) states, where mutations in single immune system genes predispose individuals to certain infectious agents and not others, are experiments of nature that hold important lessons for the immunologist. The number of genetically defined PIDs is rising rapidly, as is the opportunity to learn from them. Epstein-Barr virus (EBV), a human herpesvirus, has long been of interest because of its complex interaction with the immune system. Thus, it causes both infectious mononucleosis (IM), an immunopathologic disease associated with exaggerated host responses, and at least one malignancy, EBV-positive lymphoproliferative disease, when those responses are impaired. Here, we describe the full range of PIDs currently linked with an increased risk of EBV-associated disease. These provide examples where IM-like immunopathology is fatally exaggerated, and others where responses impaired at the stage of induction, expansion, or effector function predispose to malignancy. Current evidence from this rapidly moving field supports the view that lesions in both natural killer cell and T cell function can lead to EBV pathology.

Long-term endoscopic follow-up in small bowel transplant recipients: single-center series

BACKGROUND

The reliability of endoscopic findings after adult intestinal transplantation on short-term follow-up has been shown. The aim of this study was to evaluate in a long-term follow-up the diagnostic value of endoscopies compared with the biopsy value.

METHODS

We evaluated 52 endoscopies over a period of 2 years (2 in each patient in 2010 and 1 in each patient in 2011, plus 1 endoscopy for suspected post-transplant lymphoproliferative disease [PTLD]) on 17 recipients transplanted between the years 2000 and 2006 (more than 5 years of follow-up).

RESULTS

All the 52 endoscopic findings were comparable to biopsy definitive results: only 1 case of mild enteritis and 1 case of Epstein-Barr virus (EBV) chronic infection at biopsy were not diagnosed by endoscopy. One case of rectal PTLD and 1 of EBV-related enteritis were diagnosed by use of both procedures. Specificity was 98%: we did not calculate sensitivity because no episodes of rejection were diagnosed because recipients were stable in long-term follow-up.

CONCLUSIONS

Endoscopy is a reliable procedure even on a long-term follow-up after intestinal transplantation, allowing a support to biopsy for diagnosis on adult recipients, especially for EBV infections and PTLD surveillance.

Brentuximab vedotin demonstrates objective responses in a phase 2 study of relapsed/refractory DLBCL with variable CD30 expression

Brentuximab vedotin was active in DLBCL across a range of CD30 expression levels, and objective responses occurred in 44% of patients.

Epstein-Barr virus--associated posttransplantation lymphoproliferative disorder with tacrolimus metabolism deterioration in infants after living-donor liver transplantation

BACKGROUND

Posttransplantation lymphoproliferative disorder (PTLD) in infants after liver transplantation is strongly associated with tacrolimus (Tac) administration and primary Epstein-Barr virus (EBV) transmission.

METHODS

From 1991 to 2012, 32 survivors younger than 2 years who had undergone living-donor liver transplantation using Tac for primary immunosuppression were retrospectively investigated for changes in Tac trough levels before and at the onset of posttransplantation viral infection episodes.

RESULTS

Twenty-one recipients experienced 33 viral infection episodes associated with EBV-related PTLD (n = 5), symptomatic EBV infection without development of PTLD (n = 8), and other viral infections (n = 20). Although the average Tac trough levels during the 2 months before the onset of viral infection episodes were similar among the 33 episodes (9.0 ± 2.8 ng/mL), the Tac trough levels at the onset were significantly higher in the episodes with PTLD than in those with EBV infection without the development of PTLD and with other viral infections (19.2 ± 9.0 ng/mL vs. 9.3 ± 5.2 ng/mL and 10.6 ± 5.1 ng/mL, respectively) (P<0.05). Tacrolimus trough levels at the onset of PTLD were significantly higher during the 2 months before the onset (median, 1.83 times higher than average) compared with EBV infection (1.14 times higher) and other viral infections (1.06 times higher) (P<0.05). The Tac blood concentration-to-dose ratio at the onset of PTLD was more than twice as high as the average value during the 2 months before the onset.

CONCLUSION

Deteriorated Tac metabolism accompanied by a positive change in the blood EBV DNA load may enable us to predict the development of PTLD in liver-transplanted infants with viral infection.

The immunology of Epstein-Barr virus-induced disease

Epstein-Barr virus (EBV) is usually acquired silently early in life and carried thereafter as an asymptomatic infection of the B lymphoid system. However, many circumstances disturb the delicate EBV-host balance and cause the virus to display its pathogenic potential. Thus, primary infection in adolescence can manifest as infectious mononucleosis (IM), as a fatal illness that magnifies the immunopathology of IM in boys with the X-linked lymphoproliferative disease trait, and as a chronic active disease leading to life-threatening hemophagocytosis in rare cases of T or natural killer (NK) cell infection. Patients with primary immunodeficiencies affecting the NK and/or T cell systems, as well as immunosuppressed transplant recipients, handle EBV infections poorly, and many are at increased risk of virus-driven B-lymphoproliferative disease. By contrast, a range of other EBV-positive malignancies of lymphoid or epithelial origin arise in individuals with seemingly intact immune systems through mechanisms that remain to be understood.

Asymptomatic post-transplant lymphoproliferative disorder diagnosed at one year protocol renal allograft biopsy

Post-transplant lymphoproliferative disorder (PTLD) is a neoplastic complication with a potentially fatal outcome that develops as a consequence of immunosuppression, and is mainly associated with Epstein-Barr virus (EBV) infection. A 70-year-old woman underwent a live unrelated, ABO-incompatible renal transplant for end-stage renal disease. One year after transplantation, protocol biopsy revealed pathological changes indicative of the histological subtype of 'early lesions of PTLD' according to the World Health Organization classification, while the patient showed no clinical signs or symptoms. The patient was finally diagnosed with EBV-positive PTLD by in situ hybridization for EBER (EBV-encoded RNA), and was successfully treated based on the reduction of immunosuppression. Protocol biopsy within the first post-transplant year is the only diagnostic measure to detect asymptomatic early PTLD, which allows for early intervention and leads to better outcomes.

Post-transplant malignancy: a burdensome complication in renal allograft recipients in Korea

Cancer has been a serious complication of kidney transplantation ever since the outcome of this procedure improved. The incidence of cancer among kidney transplant (KT) recipients is increasing, and these patients have a higher risk of developing cancer than the general population. The present retrospective cohort study compared the cancer rate of kidney recipients in a single transplantation center in Korea with that in healthy Korean individuals using the standardized incidence ratio (SIR). The medical records of all 2365 patients who underwent renal transplantation between 1989 and 2009 were reviewed retrospectively. During the study period, 136 renal allograft recipients developed 140 malignancies. The cumulative cancer incidence one, five, 10, and 15 yr post-transplantation was 0.60%, 3.24%, 5.69%, and 8.90%, respectively. Non-Hodgkin lymphoma (NHL) and thyroid cancer were the most common cancers after renal transplantation, occurring significantly more frequently than in the general Korean population. The SIR of all cancers was 1.9 (women: 2.4; men: 1.6). Comparison with similar studies in Korea and other countries suggests transplant center-related differences dictate post-transplant malignancy incidence more strongly than ethnic or geographic factors. Early surveillance programs for de novo malignancies after kidney transplantation focusing on kidney-transplantation-related tumors and postoperative time period should be established.

Posttransplantation lymphoproliferative disease: proposed imaging classification

Posttransplantation lymphoproliferative disease (PTLD) is the second most common tumor in adult transplant recipients. Most cases of PTLD are attributed to Epstein-Barr virus. Decreased levels of immunosurveillance against this tumor virus as a result of immunosuppressive regimens are thought to account for most cases of PTLD. Histologically, PTLD ranges from relatively benign lymphoid hyperplasia to poorly differentiated lymphoma, and tissue sampling is required to establish the subtype. The frequency of PTLD varies depending on the type of allograft and immunosuppressive regimen. PTLD has a bimodal manifestation, with most cases occurring within the first year after transplantation and a second peak occurring 4-5 years after transplantation. Patients are often asymptomatic or present with nonspecific symptoms, and a mass visible at imaging may be the first clue to the diagnosis. Imaging plays an important role in identifying the presence of disease, guiding tissue sampling, and evaluating response to treatment. The appearance of PTLD at imaging can vary. It may be nodal or extranodal. Extranodal disease may involve the gastrointestinal tract, solid organs, or central nervous system. Solid organ lesions may be solitary or multiple, infiltrate beyond the organ margins, and obstruct organ outflow. Suggestive imaging findings should prompt tissue sampling, because knowledge of the PTLD subtype is imperative for appropriate treatment. Treatment options include reducing immunosuppression, chemotherapy, radiation therapy, and surgical resection of isolated lesions.

Post-transplant lymphoproliferative disease (PTLD): risk factors, diagnosis, and current treatment strategies

Post-transplant lymphoproliferative diseases (PTLD) are heterogeneous lymphoid disorders ranging from indolent polyclonal proliferations to aggressive lymphomas that complicate solid organ or hematopoietic transplantation. Risk factors for PTLD include viral infections, degree of immunosuppression, recipient age and race, allograft type, and host genetic variations. Clinically, extra-nodal disease is common including 10-15 % presenting with central nervous system (CNS) disease. Most PTLD cases are B cell (5-10 % T/NK cell or Hodgkin lymphoma), while over one-third are EBV-negative. World Health Organization (WHO) diagnostic categories are: early lesions, polymorphic, and monomorphic PTLD; although in practice, a clear separation is not always possible. Therapeutically, reduction in immunosuppression remains a mainstay, and recent data has documented the importance of rituximab +/- combination chemotherapy. Therapy for primary CNS PTLD should be managed according to immunocompetent CNS paradigms. Finally, novel treatment strategies for PTLD have emerged, including adoptive immunotherapy and rational targeted therapeutics (e.g., anti-CD30 based therapy and downstream signaling pathways of latent membrane protein-2A).