A population-based study of 135 lymphomas after solid organ transplantation: The role of Epstein-Barr virus, hepatitis C and diffuse large B-cell lymphoma subtype in clinical presentation and survival

NOTCH1 promotes the elevation of GM-CSF and IL-6 through the EZH2/STAT3 pathway to facilitate the fibrotic state of the myocardium in DLBCL

OBJECTIVE

Investigate the role of the Neurogenic locus notch homolog protein 1 (NOTCH1) signaling pathway in Diffuse large B-cell lymphoma (DLBCL)-related heart pathogenesis.

METHODS

Utilize R (version 4.2.1) to retrieve DLBCL and myocardial infarction datasets from the GEO database, normalize data with limma, perform differential analysis and GO analysis with GOplot, and visualize findings with ggplot2. Various assays were conducted including stable cell line construction, myocardial infarction modeling, imaging, Western Blot, ELISA, staining, and functional assays.

RESULTS

Significant gene expression and pathway disparities were found between DLBCL and myocardial infarction samples. NOTCH1, The molecules named Recosomal-binding protein 70 (RBP-J), zeste 2 polycomb repressive complex 2 subunit (EZH2), trimethylated histone H3 at lysine 27 (H3K27me3), Signal Transducer And Activator Of Transcription 3 (STAT3) and Jumonji domain containing-3 (JMJD3) matters a lot in DLBCL. NOTCH1 inhibition decreased DLBCL cell proliferation and activity, reduced inflammatory factors, and improved myocardial fibrosis and infarction severity. NOTCH1 inhibits Granulocyte-macrophage colony-stimulating factor (GM-CSF) and Interleukin-6 (IL-6) expressions depending on STAT3 and EZH2. Co-culturing with DLBCL cells increased fibroblast proliferation, invasion, and fibrosis.

CONCLUSION

NOTCH1 signaling influences DLBCL development and myocardial infarction severity through the EZH2/STAT3 pathway, leading to increased heart fibrosis.

The IPTA Nashville consensus conference on post-transplant lymphoproliferative disorders after solid organ transplantation in children: IV-consensus guidelines for the management of post-transplant lymphoproliferative disorders in children and adolescents

The International Pediatric Transplant Association convened an expert consensus conference to assess current evidence and develop recommendations for various aspects of care relating to post-transplant lymphoproliferative disorders (PTLD) after pediatric solid organ transplantation. This report addresses the outcomes of deliberations by the PTLD Management Working Group. A strong recommendation was made for reduction in immunosuppression as the first step in management. Similarly, strong recommendations were made for the use of the anti-CD20 monoclonal antibody (rituximab) as was the case for chemotherapy in selected scenarios. In some scenarios, there is uncoupling of the strength of the recommendations from the available evidence in situations where such evidence is lacking but collective clinical experiences drive decision-making. Of note, there are no large, randomized phase III trials of any treatment for PTLD in the pediatric age group. Current gaps and future research priorities are highlighted.

Post-transplant lymphoproliferative disease in children, adolescents, and young adults

Post-transplant lymphoproliferative disease (PTLD) remains a major complication of transplantation. PTLD is a rare entity and very heterogenous making consensus on diagnosis and treatment very challenging. The majority are Epstein-Barr virus (EBV) driven, CD20+ B-cell proliferations. PTLD does occur following hematopoietic stem cell transplant (HSCT), but due to the relative short risk period and efficacy of pre-emptive therapy, PTLD following HSCT will not be discussed in this review. This review will focus on the epidemiology, role of EBV, clinical presentation, diagnosis and evaluation and the current and emerging treatment strategies for pediatric PTLD following solid organ transplantation.

Diagnosis and management of post-transplant lymphoproliferative disease following solid organ transplantation in children, adolescents, and young adults

Post-transplant Lymphoproliferative Disease (PTLD) remains a major complication of solid organ transplantation (SOT) in pediatric patients. The majority are Epstein-Barr Virus (EBV) driven CD20⁺ B-cell proliferations responsive to reduction to immunosuppression and anti-CD20 directed immunotherapy. This review focusses on the epidemiology, role of EBV, clinical presentation, current treatment strategies, adoptive immunotherapy and future research in EBV + PTLD in pediatric patients.

Diffuse large B cell lymphoma CD5-positive arising in an immune deficiency and immune dysregulation setting: A case report and brief review of the literature

RATIONALE

In the era of antiretroviral therapy, lymphoma is the primary cause of cancer-related death among human immunodeficiency virus (HIV)-infected people and the most prevalent and aggressive non-Hodgkin lymphoma is diffuse large B cell lymphoma, which usually has an aggressive clinical course. CD5-positive diffuse large B cell lymphoma (DLBCL) is an insufficiently studied, relatively new entity, which accounts for 5% to 10% of the DLBCL population. The current study presents the clinicopathological features, diagnostic approach, and clinical outcomes of this HIV-related lymphoma and highlights the importance of the early diagnosis of CD5-positive DLBCL.

PATIENT CONCERNS

We present a case of a 30-year-old male patient, with a medical history of HIV-positive serology and antiviral treatment, presenting with diffuse abdominal pain and symptoms related to obstruction or perforation, followed by exploratory laparotomy and surgical resection of the small intestine with other areas of involvement. The surgical specimen was morphologically evaluated and immunohistochemical stained.

DIAGNOSES AND INTERVENTIONS

Histopathologic examination revealed a diffuse neoplastic proliferation of large B lymphocytes within the small intestine, lacking features of other defined types of large B cell lymphoma. The diagnosis of CD5-positive DLBCL subtype was made after immunostaining with twelve monoclonal antibodies (CD3, CD5, CD10, CD20, CD23, CD30, CD68, Cyclin D1, MUM1, Bcl2, Bcl6, and Ki-67). The expression profile of immunohistochemical markers (CD10, Bcl6, and MUM1) established the cell of origin of this case of DLBCL by using the Hans algorithm.

LESSONS

The current report highlights the importance of early diagnosis of CD5-positive DLBCL because of its poor prognosis and calls attention to the critical importance to identify immunodeficiencies because doing so affects the types of treatments available. Although cell-of-origin is useful for predicting outcomes, the germinal center B cell like and activated-B cell like subtypes remain heterogeneous, with better, and worse prognostic subsets within each group.

Characteristics and Outcome of Post-Transplant Lymphoproliferative Disorders After Solid Organ Transplantation: A Single Center Experience of 196 Patients Over 30 Years

Post-transplant lymphoproliferative disorder (PTLD) is a rare but life-threatening complication after transplantation. In this retrospective, monocentric study we aimed to collect real life data regarding PTLD and determine the role of Epstein Barr Virus (EBV) status and year of diagnosis on prognosis. We identified 196 biopsy-proven PTLD after solid organ transplantation (SOT) diagnosed at the University Hospitals Leuven (Belgium) from 1989 to 2019. EBV status was positive in 61% of PTLD. The median overall survival (OS) was 5.7 years (95% CI: 2.99-11.1). Although EBV positivity was not significantly correlated with OS in multivariate analyses (HR: 1.44 (95% CI: 0.93-2.24); p = 0.10), subgroup analysis showed a significantly better median OS for EBV negative post-transplant diffuse large B-cell lymphoma (DLBCL) compared to EBV positive post-transplant DLBCL (8.8 versus 2.5 years respectively; p = 0.0365). There was a significant relation between year of PTLD diagnosis and OS: the more recent the PTLD diagnosis, the lower the risk for death (adjusted HR: 0.962 (95% CI: 0.931-0.933); p = 0.017). In conclusion, the prognosis of PTLD after SOT has improved in the past decades. Our analysis shows a significant relation between EBV status and OS in post-transplant DLBCL.

Epstein-Barr virus-associated posttransplant lymphoproliferative disorders: new insights in pathogenesis, classification and treatment

PURPOSE OF REVIEW

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication following transplantation from an allogeneic donor. Epstein-Barr Virus (EBV) is involved in a substantial number of cases. In this review, we aim to summarize recent knowledge on pathogenesis, classification and treatment of EBV + PTLD.

RECENT FINDINGS

New insights in the complex oncogenic properties of EBV antigens noncoding Ribonucleic acids (RNAs), especially EBV MicroRNA (miRNAs), have increased our knowledge of the pathogenesis of EBV + PTLD. In addition the potential influence of EBV on the tumor microenvironment is becoming clearer, paving the way for new types of immunotherapy. Currently PTLD is classified according to the World Health Organization classification together with other lymphoproliferative disorders, based on the specific immunosuppression. However, a new framework integrating all types of lymphoproliferative disorders in all different settings of immune deficiency and dysregulation is needed. Although treatment of EBV + and EBV - PTLD was largely similar in the past, EBV-directed therapies are currently increasingly used.

SUMMARY

The use of EBV-directed therapies and new agents, based on better understanding of pathogenesis and classification of PTLD, will change the treatment landscape of EBV + PTLD in the next era.

Gastrointestinal manifestations, risk factors, and management in patients with post-transplant lymphoproliferative disorder: A systematic review

BACKGROUND

Patients with a history of solid organ transplantation (SOT) or hematopoietic stem cell transplantation (HSCT) are at an increased risk of developing post-transplant lymphoproliferative disorder (PTLD). The gastrointestinal (GI) tract is commonly affected as it has an abundance of B and T cells.

AIM

To determine typical GI-manifestations, risk factors for developing PTLD, and management.

METHODS

Major databases were searched until November 2021.

RESULTS

Non-case report studies that described GI manifestations of PTLD, risk factors for developing PTLD, and management of PTLD were included. Nine articles written within the last 20 years were included in the review. All articles found that patients with a history of SOT, regardless of transplanted organ, have a propensity to develop GI-PTLD.

CONCLUSION

GI tract manifestations may be nonspecific; therefore, consideration of risk factors is crucial for identifying GI-PTLD. Like other lymphoma variants, PTLD is very aggressive making early diagnosis key to prognosis. Initial treatment is reduction of immunosuppression which is effective in more than 50% of cases; however, additional therapy including rituximab, chemotherapy, and surgery may also be required.

Treatment of Epstein-Barr Virus-Related Post-Renal Transplantation Development of Diffuse Large B Cell Lymphoma of the Distal Ureter: A Case Report

Posttransplant lymphoproliferative disorder with involvement of the donor urogenital tissue is a rare and serious complication of solid organ transplant. We report an adult kidney transplant recipient who developed the diffuse large B cell lymphoma of the distal ureter in the setting of new allograft nephropathy. Early intervention, reduction of immunosuppression, surgical reconstruction and chemotherapy salvaged the allograft kidney and averted a fatal outcome. The renal function recovered to the baseline with creatinine ranging between 1.3 and 1.5. The patient did not require dialysis at any point after ureteral stent placement and reconstructive surgery. In addition, the case highlights the importance of multidisciplinary management involving transplant nephrology, oncology, transplant surgery, and urology in such a complicated disease process.

Comparison of Post-Transplantation Lymphoproliferative Disorder Risk and Prognostic Factors between Kidney and Liver Transplant Recipients

Post-transplantation lymphoproliferative disorder (PTLD) is a life-threatening complication of solid organ transplantation (SOT). Its development risk varies among organ graft recipients. In this study, retrospective data were analyzed to compare PTLD’s risk and prognostic factors between adult kidney and liver transplant recipients (KTRs and LTRs, respectively). Over 15 years, 2598 KTRs and 1378 LTRs were under observation at our center. Sixteen KTRs (0.62%) and twenty-three LTRs (1.67%) were diagnosed with PTLD. PTLD developed earlier in LTRs (p < 0.001), SOT patients > 45 years old (p = 0.002), and patients receiving tacrolimus (p < 0.001) or not receiving cyclosporin (p = 0.03) at diagnosis. Tacrolimus use, male sex, and age > 45 years old significantly affected the time of PTLD onset in KTRs (hazard ratio (HR) = 18.6, 7.9 and 5.2, respectively). Survival was longer in LTRs < 45 years old (p < 0.009). LTRs were more likely than KTRs to achieve complete remission (p = 0.039). Factors affecting PTLD development and outcome differ between KTRs and LTRs; thus, these populations should be separately evaluated in future studies.

Viral infections in lung transplantation

Viral infections account for up to 30% of all infectious complications in lung transplant recipients, remaining a significant cause of morbidity and even mortality. Impact of viral infections is not only due to the direct effects of viral replication, but also to immunologically-mediated lung injury that may lead to acute rejection and chronic lung allograft dysfunction. This has particularly been seen in infections caused by herpesviruses and respiratory viruses. The implementation of universal preventive measures against cytomegalovirus (CMV) and influenza (by means of antiviral prophylaxis and vaccination, respectively) and administration of early antiviral treatment have reduced the burden of these diseases and potentially their role in affecting allograft outcomes. New antivirals against CMV for prophylaxis and for treatment of antiviral-resistant CMV infection are currently being evaluated in transplant recipients, and may continue to improve the management of CMV in lung transplant recipients. However, new therapeutic and preventive strategies are highly needed for other viruses such as respiratory syncytial virus (RSV) or parainfluenza virus (PIV), including new antivirals and vaccines. This is particularly important in the advent of the COVID-19 pandemic, for which several unanswered questions remain, in particular on the best antiviral and immunomodulatory regimen for decreasing mortality specifically in lung transplant recipients. In conclusion, the appropriate management of viral complications after transplantation remain an essential step to continue improving survival and quality of life of lung transplant recipients.

Posttransplant Lymphoproliferative Disorder Status Post-Solid Organ Transplant Presenting to the Emergency Department: Single Institute Experience

OBJECTIVE

The objective of this study was to evaluate the clinical, laboratory, imaging, and pathology findings associated with emergency department presentations of posttransplant lymphoproliferative disorder (PTLD) after solid organ transplant (SOT).

METHODS

Fifteen patients presenting to a single tertiary care center between 2004 and 2019 with PTLD after SOT were identified from a pathology database. Twelve patients presenting through the emergency department were included in the study. Demographic, clinical, imaging, pathology, treatment, and outcome data were reviewed.

RESULTS

Among this 12 patient cohort (7 men; mean age, 44.2 years), transplant history included 4 combined kidney/pancreas, 4 kidney, 2 liver, 1 cardiac, and 1 lung. Mean time from transplant to diagnosis was 7.6 years. Posttransplant lymphoproliferative disorder was identified on initial computed tomography scans in 10 of 12 patients. The most common sites for PTLD development were the gastrointestinal tract (4/12) and liver (3/12). Outcomes included resolution of PTLD in 9 of 12 patients, with 3 patients dying within 6 months of diagnosis.

CONCLUSIONS

Posttransplant lymphoproliferative disorder is a serious consequence of solid organ transplantation that can present in various locations and with varied symptomatology in the emergency setting. Other posttransplant complications may present similarly including chronic rejection and infection. Posttransplant lymphoproliferative disorder should be considered in SOT patients presenting with worsening abdominal pain or constitutional symptoms, even with normal laboratory workup.

Distinct immunopathological mechanisms of EBV-positive and EBV-negative posttransplant lymphoproliferative disorders

EBV-positive and EBV-negative posttransplant lymphoproliferative disorders (PTLDs) arise in different immunovirological contexts and might have distinct pathophysiologies. To examine this hypothesis, we conducted a multicentric prospective study with 56 EBV-positive and 39 EBV-negative PTLD patients of the K-VIROGREF cohort, recruited at PTLD diagnosis and before treatment (2013-2019), and compared them to PTLD-free Transplant Controls (TC, n = 21). We measured absolute lymphocyte counts (n = 108), analyzed NK- and T cell phenotypes (n = 49 and 94), and performed EBV-specific functional assays (n = 16 and 42) by multiparameter flow cytometry and ELISpot-IFNγ assays (n = 50). EBV-negative PTLD patients, NK cells overexpressed Tim-3; the 2-year progression-free survival (PFS) was poorer in patients with a CD4 lymphopenia (CD4⁺ <300 cells/mm³ , p <  .001). EBV-positive PTLD patients presented a profound NK-cell lymphopenia (median = 60 cells/mm³ ) and a high proportion of NK cells expressing PD-1 (vs. TC, p = .029) and apoptosis markers (vs. TC, p < .001). EBV-specific T cells of EBV-positive PTLD patients circulated in low proportions, showed immune exhaustion (p = .013 vs. TC) and poorly recognized the N-terminal portion of EBNA-3A viral protein. Altogether, this broad comparison of EBV-positive and EBV-negative PTLDs highlight distinct patterns of immunopathological mechanisms between these two diseases and provide new clues for immunotherapeutic strategies and PTLD prognosis.

Prior antithymocyte globulin therapy and survival in post-transplant lymphoproliferative disorders

Background: Treatment with antithymocyte globulin (ATG) is a well-recognized risk factor for the development of post-transplant lymphoproliferative disorders (PTLD) after solid organ transplantation, but it is unknown how its use affects overall survival after PTLD.Methods: A total of 114 patients with PTLD and available data on immunosuppressive regimen were included from a nation-wide case series of solid organ transplant recipients in Sweden. Prior use of ATG was correlated to clinical features, PTLD subtype, and survival.Results: A total of 47 (41%) patients had received ATG prior to the diagnosis of PTLD. The ATG-treated patients were more likely to be recipients of hearts or lungs, and less likely of kidneys (p < 0.01). They had experienced more acute rejections (p = 0.02). The PTLDs arose earlier, median 2.0 vs. 6.6 years post-transplant (p = 0.002) and were more often situated in the allograft (32% vs. 7%, p < 0.001) in patients with prior ATG vs. no ATG treatment. The PTLDs in the ATG group were more often Epstein-Barr virus-positive (80% vs. 40%, p < 0.001). There were more polymorphic PTLDs (17% vs. 1.5%, p = 0.004) and less T-cell PTLDs (4% vs. 19%, p = 0.02) in the ATG group than in the no ATG group. Diffuse large B-cell lymphoma was equally common in patients with and without prior ATG therapy, but the non-germinal center subtype was more frequent in the ATG group (p = 0.001). In an adjusted Cox proportional hazards regression model, prior ATG treatment and better performance status were associated with superior overall survival, whereas older age, T-cell subtype of PTLD, presence of B symptoms, and elevated lactate dehydrogenase were associated with inferior overall survival. Patients receiving ATG solely as rejection therapy had superior overall survival compared with those receiving ATG as induction therapy or both (p = 0.03).Conclusions: ATG therapy, especially rejection therapy, prior to PTLD development is an independent prognostic factor for superior overall survival after PTLD diagnosis.

Joining Efforts for PTLD: Lessons Learned from Comparing the Approach and Treatment Strategies Across the Pediatric and Adult Age Spectra

PURPOSE OF REVIEW

Post-transplant lymphoproliferative disorders are a rare and heterogeneous group of diseases, where large prospective studies have been difficult to perform and treatment paradigms are often based on retrospective studies. Here, we critically analyze and present the clinical algorithms commonly used for this disease, with a special focus on the challenges and differences of the approaches in the adult and pediatric populations.

RECENT FINDINGS

Clinical trials exploring combinations of immunochemotherapies with a sequential and risk-stratified strategy have demonstrated exciting results, but are hampered from specialty and age-determined silos. Approaches introducing novel-targeted therapies and cellular therapies are currently being explored with a goal of joining efforts across the pediatric and adult age spectra. We propose that future therapeutic approaches would benefit from combining pediatric and adult PTLD efforts, gaining from the experience garnered from the age- and subtype-specific tailored strategies, with the aim of limiting treatment-related toxicities while maximizing the efficacy. Joining of efforts holds enormous potential for accelerating access to novel therapeutic strategies for PTLD in the near future.

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

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

Post-transplant lymphoproliferative disorder in adult renal transplant recipients: case series and review of literature

Post-transplant lymphoproliferative disorder (PTLD) is serious life-threating complication of transplantation. The clinical picture differs from lymphomas observed in the general population, with different manifestation, histopathology, higher aggressiveness with involvement of sites beyond the primary lymph node, and poorer outcome.

The objective of the study was to present nine cases of PTLD observed in our centre among the kidney transplant recipient population and discuss the results with up-to-date literature. We performed a retrospective single-centre assessment of PTLD incidence in the cohorts of kidney transplant recipients followed by our centre. We found nine cases of PTLD, five men and four woman, aged from 26 to 67 years at the time of diagnosis (mean [SD] 48 [5] years), transplanted between 1997 and 2013.

The disease was diagnosed between 2002 and 2017, from 6 to 440 months after transplantation (mean [SD] 96 [137] months). A diffuse large B-cell lymphoma was found in seven cases early as well as late after transplantation, and two patients presented T-cell lymphoma. Five patients achieved complete remission with no relapses after 6 to 13 months of treatment. In three cases the remission was achieved by switching to mammalian target of rapamycin inhibitors (mTORi) only. Four recipients died from 2 weeks to 15 months after PTLD was diagnosed.

Although the diagnostic criteria of different forms of PTLD are commonly known, rapid and correct diagnosis is not easy. PTLD is a relatively a rare disease, so there are too few studies and little consensus on the optimal treatment.

18F-FDG PET/CT for Evaluation of Post-Transplant Lymphoproliferative Disorder (PTLD)

Post-transplant lymphoproliferative disorders (PTLD) are a spectrum of heterogeneous lymphoproliferative conditions that are serious and possibly fatal complications after solid organ or allogenic hematopoietic stem cell transplantation. Most PTLD are attributed to Epstein-Barr virus reactivation in B-cells in the setting of immunosuppression after transplantation. Early diagnosis, accurate staging, and timely treatment are of vital importance to reduce morbidity and mortality. Given the often nonspecific clinical presentation and disease heterogeneity of PTLD, tissue biopsy and histopathological analysis are essential to establish diagnosis and most importantly, determine the subtype of PTLD, which guides treatment options. Advanced imaging modalities such as ¹⁸F-FDG PET/CT have played an increasingly important role and have shown high sensitivity and specificity in detection, staging, and assessing treatment response in multiple clinical studies over the last two decades. However, larger multicenter prospective validation is still needed to further establish the clinical utility of PET imaging in the management of PTLD. Significantly, new hybrid imaging modalities such as PET/MR may help reduce radiation exposure, which is especially important in pediatric transplant patients.

Haematological disorders following kidney transplantation

Transplantation offers cure for some haematological cancers, end-stage organ failure, but at the cost of long-term complications. Renal transplantation is the best-known kidney replacement therapy and it can prolong end-stage renal disease patient lives for decades. However, patients after renal transplantation are at a higher risk of developing different complications connected not only with surgical procedure but also with immunosuppressive treatment, chronic kidney disease progression and rejection processes. Various blood disorders can develop in post-transplant patients ranging from relatively benign anaemia through cytopenias to therapy-related myelodysplasia and acute myeloid leukaemia (AML) and post-transplant lymphoproliferative disorders followed by a rare and fatal condition of thrombotic microangiopathy and haemophagocytic syndrome. So far literature mainly focused on the post-transplant lymphoproliferative disease. In this review, a variety of haematological problems after transplantation ranging from rare disorders such as myelodysplasia and AML to relatively common conditions such as anaemia and iron deficiency are presented with up-to-date diagnosis and management.

Primary central nervous system lymphoma after heart transplantation: A case report and literature review

RATIONALE

The heart transplantation is the most important treatment for patients with end-stage severe heart disease who failed to conventional therapy. Post-transplant lymphoproliferative disorder is the second most common malignancy in heart transplant recipients. However, primary central nervous system lymphoma (PCNSL) after heart transplantation is an extremely rare condition.

PATIENTS CONCERNS

This report described a 53-year-old male who was diagnosed as PCNSL 17 months after heart transplantation.

DIAGNOSES

The patient was admitted to the local hospital presenting with dizziness, headache, and reduced left-sided power and sensation for 1 week. He had a medical history of heart transplantation because of the dilated cardiomyopathy 17 months ago and had a 17-month history of immunosuppressive therapy with tacrolimus. A computed tomography scan of the brain revealed a bulky mass in the right temporal lobe. The emergency intracranial mass resection and cerebral decompression were performed in our hospital. The histopathology of the brain lesions showed diffuse large B-cell lymphoma. A further FDG positron emission tomography-computed tomography scan of the whole body showed no significantly increased metabolic activity in other regions. The final diagnosis of this patient was PCNSL after heart transplantation.

INTERVENTIONS

Given the poor health condition, with the patient's consent, the whole brain radiotherapy was performed with supportive care.

OUTCOMES

The disease deteriorated rapidly during the period of receiving radiotherapy, and he died within 2 months from the diagnosis.

LESSONS

PCNSL after heart transplantation is an extremely rare phenomenon with extremely poor prognosis. We should pay close attention to the heart recipients, especially when the patients present with neurological symptoms and signs. The available treatment options for PCNS-post-transplant lymphoproliferative disorder include the reduction of immunosuppressive drugs, immune-chemotherapy, operation, radiotherapy. However, individual treatments for heart transplant recipients with PCNSL should be based on the performance status and tolerance to treatment, combined with the doctor's experience and supportive care.

CD30 expression and survival in posttransplant lymphoproliferative disorders

Background: Post-transplant lymphoproliferative disorder (PTLD) is a rare but life-threatening complication of transplantation. For refractory and relapsed PTLD new therapies are needed, such as the antibody-drug conjugate brentuximab vedotin that targets CD30. There is limited knowledge of CD30 expression in various subtypes of PTLD and its correlation to clinicopathological features. Therefore, we studied the expression of CD30 in PTLD following solid organ transplantation and correlated CD30 expression to PTLD subtype, Epstein-Barr virus (EBV)-status, intratumoral regulatory T-cells (Tregs), clinical features, and outcome.Methods: We included 50 cases of PTLD from a nation-wide study of PTLDs following solid organ transplantation in Sweden. The tumor biopsies were reevaluated, and clinical data were collected. CD30 expression on tumor cells was analyzed by immunohistochemistry with the clone Ber-H2. Thirty-one cases were stained with clone 236 A/E7 for detection of forkhead box protein 3 (FoxP3, a Treg biomarker).Results: The case series consisted of 6% polymorphic, 88% monomorphic, and 6% Hodgkin lymphoma-like PTLDs and 53% of the cases were EBV+. Overall, 70% (35/50) of the PTLDs were CD30+ (≥1% CD30+ tumor cells) and 30% (15/50) were CD30-. All polymorphic PTLDs (n = 3) and Hodgkin lymphomas (n = 3), 88% (14/16) of non-germinal center type of diffuse large B-cell lymphoma (DLBCL), and 75% (9/12) of T-cell PTLDs were CD30+ whereas all germinal center-type of DLBCL (n = 5) and Burkitt type PTLD (n = 2) were CD30-. CD30+ PTLD tended to be EBV+ more frequently (p = .07) and occurred earlier posttransplant (2.1 vs. 8.2 years, p = .01) than CD30- PTLD. Type of transplant and localization of the tumor did not differ between the groups except that CNS engagement was more common in CD30- PTLD (p = .02). CD30-status was not associated with presence of intratumoral Tregs or overall survival.Conclusion: Expression of CD30 varied with PTLD subtype. There was no association between CD30 and survival, regardless of subtype.

Post-transplant Lymphoproliferative Disorder of Naso-orbital Region in Adult Renal Transplant Recipients: A Case Report and Literature Review

Post-transplant lymphoproliferative disorder (PTLD) is an uncommon but fatal complication following both solid organ and hematologic stem cell transplantations. Epstein-Barr virus (EBV) has been considered a main etiologic agent causing PTLD, especially in the first year after transplantation. Extranodal manifestations are frequently found in PTLD; however, naso-orbital involvement in adults is rare. We report a case of EBV-associated PTLD of the naso-orbital region in a 72-year-old patient that occurred 10 years after kidney transplant. Six additional adults with naso-orbital PTLD were identified after completing this literature review, including 2 cases with eyelid swelling, 3 cases with proptosis, and 1 case with facial numbness. The majority of cases occurred after 1 year of transplantation and were associated with EBV. This report emphasizes recognizing PTLD as differential diagnosis in transplant recipients who present with naso-orbital symptoms.

Isolated peritoneal lymphomatosis defined as post-transplant lymphoproliferative disorder after a liver transplant: A case report

BACKGROUND

Post-transplant lymphoproliferative disorder (PTLD) is a fatal complication of solid organ transplantation or allogenic hematopoietic stem cell transplantation that is associated with immunosuppressive therapy. Potential manifestations are diverse, ranging from reactive lymphoid hyperplasia to high-grade lymphoma. PTLD is usually of B-cell origin and associated with Epstein-Barr virus (EBV) infection. Herein, we describe a case of PTLD involving the peritoneal omentum. There has been only case of PTLD as a diffuse large B-cell lymphoma (DLBCL) in the peritoneum.

CASE SUMMARY

The patient was a 62-year-old man who had been receiving immunosuppressive therapy with tacrolimus since undergoing a liver transplant 15 years prior. He reported that he had experienced abdominal discomfort and anorexia 1 month prior to the current admission. Abdominal pelvic computed tomography (CT) revealed peritoneal and omental mass-like lesions without bowel obstruction. Ultrasonography-guided biopsy was performed, and he was histologically diagnosed with EBV-negative DLBCL. Positron emission tomography (PET)-CT depicted peritoneum and omentum involvement only, without any lymphadenopathy or organ masses, including in the gastrointestinal tract. Six cycles of chemotherapy with a “R-CHOP“ regimen (rituximab-cyclophosphamide, doxorubicin, vincristine, prednisolone) were administered, and PET-CT performed thereafter indicated complete remission.

CONCLUSION

This is the first report of isolated peritoneal lymphomatosis defined as PTLD in a liver transplant recipient.

Lymphoma of the lip after kidney transplantation: a case report

Introduction: In transplant recipients, the risk to develop cancer increases 4 fold compared to general population due to the immunosuppressive treatment. Observation: A 68 years old woman, kidney transplanted four years ago, presented with a slowly growing swelling over her left lip since six weeks. The histopathological analyses showed a non Hodgkin lymphoma. Comment: Post-transplant lymphoproliferative disorders (PTLD) is a complication developing after solid organ transplantation or allogenic hematopoietic stem cell transplantation. Immunosuppression due to the immunosuppressives drugs is considered as the most important risk factor and the incidence rate depends of transplant type, age and risk of primary Epstein-Barr virus infection. Conclusion: PTLD is a rare but serious complication. It must be suspected in all cases of intra-oral mass for a transplanted patient and requires a histopathological analysis for early diagnosis and appropriate treatment.

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

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

Remission of Late-Onset Post-Liver Transplantation Non-Hodgkin Lymphoma

We describe the clinical course of a patient who developed high-grade lymphoma during immunosuppression treatment with cyclosporine A, following liver transplantation. After anti-neoplastic polychemotherapy treatment, the remission of lymphoma was confirmed and maintained for over four years. The patient, a 27 year old female had liver transplantation at the age of 17, due to acute liver failure, caused by non-diagnosed Wilson disease. Nearly seven years post-transplantation, the patient was diagnosed with non-Hodgkin B-cell lymphoma (NHBCL), potentially induced by Cephalosporin A therapy. After the treatment with rituximab and CHOP therapy (r-CHOP protocol), remission was determined using computer tomography. Remission is maintained to date. A review of reported cases of post-transplant lymphoproliferative disorders (PTLDs) in liver transplanted (LT) patients showed that the onset of PTLDs is the highest in the first year after transplantation. In addition, remission rates of NHBCL in LT patients are not much elaborated in the literature. It is our opinion that the presented case is rare, both from the aspect of timeline of occurrence of the PTLD and the achieved remission, using r-CHOP protocol.

Donor-derived Viral Infections in Liver Transplantation

Donor-derived infections are defined as any infection present in the donor that is transmitted to 1 or more recipients. Donor-derived infections can be categorized into 2 groups: "expected" and "unexpected" infections. Expected transmissions occur when the donor is known to have an infection, such as positive serology for cytomegalovirus, Epstein Barr virus, or hepatitis B core antibody, at the time of donation. Unexpected transmissions occur when a donor has no known infection before donation, but 1 or more transplant recipients develop an infection derived from the common donor. Unexpected infections are estimated to occur in far less than 1% of solid organ transplant recipients. We will review the epidemiology, risk factors, and approaches to prevention and management of donor-derived viral infectious disease transmission in liver transplantation.

Primary central nervous system post-transplant lymphoproliferative disorders: the spectrum of imaging appearances and differential

OBJECTIVE

Central nervous system post-transplant lymphoproliferative disorder (CNS-PTLD) is a rare disease that presents with non-specific signs and symptoms. The purpose of this article is to present the imaging appearances of CNS-PTLD by magnetic resonance imaging. We highlight the differential diagnostic considerations including primary central nervous system lymphoma, glioblastoma, cerebral abscess, and metastatic disease. This is an important topic to review since in daily practice the diagnosis of CNS-PTLD is often not initially considered when present due to its rarity and the lack of radiologists' familiarity with the disease.

CONCLUSION

Knowing the unique imaging features of CNS-PTLD narrows the differential diagnosis, facilitates the diagnostic work-up, and optimizes making the diagnosis. Advanced MRI data for CNS PTLD is limited but is promising for helping with narrowing the differential diagnosis.

Management and treatment of the HCV-infected kidney transplant patient

The prevalence of hepatitis C virus infection is increased in patients with end stage kidney disease compared to the general population and is an adverse outcome determinant. Direct-acting antiviral therapy for hepatitis C virus is changing the management paradigm of infected kidney transplant candidates and recipients, with potential to reduce patient morbidity and mortality. This review describes the hepatic and nonhepatic manifestations of hepatitis C virus in kidney transplant patients as well as management and treatment strategies to optimize transplant outcomes, highlighting the importance of direct-acting antivirals in this population.

Expression of PD-1, PD-L1, and PD-L2 in posttransplant lymphoproliferative disorder after solid organ transplantation

We studied the expression of programed death 1 (PD-1) receptor and its ligands (PD-L1/-L2) by immunohistochemistry and its association with clinicopathological features in 81 posttransplant lymphoproliferative disorders (PTLDs) following solid organ transplantation. Overall, 67% (54/81) of the PTLDs were positive in any of the three immunostainings. PD-1 was detected on tumor-infiltrating cells in 41% (33/81) of the PTLDs. PD-L1 was expressed on ≥5% of the tumor cells in 50% (40/80) and PD-L2 in 32% (23/72) of the PTLDs. All Burkitt lymphomas were PD-L1 negative. Expression of PD-L1 tended to be associated with non-germinal center-type of diffuse large B-cell lymphoma (63% vs. 33% in GC-type, p = .14) and latent membrane protein-1+ PTLD (76% vs. 44% in LPM1-, p = .09). Heart recipients had more frequent PTLDs with PD-1+ microenvironment (p = .01). The frequent expression of PD-1 or -L1/-L2 in PTLD warrants further clinical evaluation of the efficacy and safety of PD-(L)1 inhibitors for refractory PTLD.

Post-transplant lymphoproliferative disorders after solid organ and hematopoietic stem cell transplantation

Post-transplant lymphoproliferative disorders (PTLD) are a rare complication after both solid organ (SOT) and allogeneic hematopoietic stem cell transplantation (allo-HSCT). In this single center retrospective study, we compared clinical, biological, and histological features, and outcomes of PTLD after both types of transplant. We identified 82 PTLD (61 after SOT and 21 after allo-HSCT). The presence of B symptoms, Waldeyer ring, spleen, central nervous system, and liver involvement, and advanced Ann-Arbor stage were more frequent in allo-HSCT recipients. PTLD had an earlier onset in allo-HSCT than in SOT cohort (4 vs. 64 months, p < .0001). PTLD was EBV-positive in 100% of allo-HSCT, in contrast to 47% of SOT (p = .0002). Four years after PTLD diagnosis, median overall survival was 32% (95% CI, 22-48) and 10% (95% CI, 2-49) in SOT and allo-HSCT recipients, respectively (p = .002). In conclusion, the clinical presentation and the outcome of PTLD varies greatly depending on the type of transplant.

Blastic Epstein-Barr virus associated post-transplant lymphoproliferative disorder after allogeneic stem cell transplantation for severe aplastic anemia

Post-transplant lymphoproliferative disorder (PTLD) is a well-recognized complication of organ transplantation. Progress has recently been made in the pathological classification of PTLD. However, the clinical course has not been clarified because of the rarity of this disease. We experienced a case of PTLD with a fulminant clinical course. The patient had been under longterm immunosuppressive treatment for aplastic anemia. He received related allogeneic hematopoietic stem cell transplantation. Soon after transplantation, he developed PTLD. According to the guidelines, we reduced immunosuppression. However, the disease course was so fulminant that there was no time for the patient to respond, and he died of multi-organ failure. There may be various clinical types of PTLD, which may include some fulminant cases. In such a case, it is not sufficient to reduce immunosuppression. The patient should be carefully observed and an appropriate individual treatment should be chosen.

Impact of the posttransplant lymphoproliferative disorder subtype on survival

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication of solid organ transplantation. Histologic heterogeneity and a lack of treatment standards have made evaluating clinical outcomes in specific patient populations difficult. This systematic literature review investigated the impact of the PTLD histologic subtype on survival in a large data set.

METHODS

Case series were identified on PubMed with the search terms post-transplant lymphoproliferative disorder/disease, PTLD, and solid organ transplantation, with additional publications identified through reference lists. The patient characteristics, immunosuppressive regimen, treatment, survival, and follow-up time for 306 cases were extracted from 94 articles, and these cases were combined with 11 cases from Emory University Hospital. Patients with a recorded subtype were included in a Kaplan-Meier survival analysis (n = 234). Cox proportional hazards regression analyses identified predictors of overall survival (OS) for each subtype and B-cell subgroup.

RESULTS

OS differed significantly between monomorphic T-cell neoplasms (median, 9 months) and polymorphic, monomorphic B-cell, and Hodgkin-type neoplasms, for which the median OS was not reached (P = .0001). Significant differences in OS among B subgroups were not detected, but there was a trend toward decreased survival for patients with Burkitt-type PTLD. Kidney transplantation and a reduction of immunosuppression were associated with increased OS for patients with B-cell neoplasms in a multivariate analysis. Immunosuppression with azathioprine was associated with decreased OS for patients with T-cell neoplasms, whereas radiotherapy was associated with improved OS for patients with that subtype.

CONCLUSIONS

The histologic subtype represents an important prognostic factor in PTLD, with patients with T-cell neoplasms exhibiting very poor OS. Possibly lower survival for certain subsets of patients with B-cell PTLD should be explored further and suggests the need for subtype-specific therapies to improve outcomes. Cancer 2018;124:2327-36. © 2018 American Cancer Society.

Contribution of solid organ transplant recipients to the pediatric non-hodgkin lymphoma burden in the United States

BACKGROUND

Pediatric solid organ transplant recipients have a 100 to 200 times higher risk of non-Hodgkin lymphoma (NHL) than the general pediatric population. Consequently, transplant-related NHL may contribute considerably to the pediatric NHL burden in the United States.

METHODS

A cohort study using a linkage between the US transplant registry and 16 cancer registries was conducted. Cancer incidence rates were calculated for people less than 20 years old in the transplant and general populations. Rates were applied to transplant registry and US census data to estimate pediatric NHL counts for transplant recipients and the general population.

RESULTS

During 1990-2012, an estimated 22,270 NHLs were diagnosed in US children and adolescents; they included 628 cases diagnosed in transplant recipients. Thus, 2.82% of pediatric NHL diagnoses in the general population (95% confidence interval [CI], 2.45%-3.19%) occurred in transplant recipients. Among transplant recipients, the most common subtypes were diffuse large B-cell lymphoma (DLBCL; 64.5% of cases) and Burkitt lymphoma (BL; 8.6%). For DLBCL and BL, transplant recipients contributed 7.62% (95% CI, 6.35%-8.88%) and 0.87% (95% CI, 0.51%-1.23%) of diagnoses, respectively. The proportion of NHLs that occurred in transplant recipients was highest among children less than 5 years old (4.46%; 95% CI, 3.24%-5.69%) and in more recent calendar years (3.73% in 2010-2012; 95% CI, 2.07%-5.39%). DLBCL patterns were similar, with transplant recipients contributing 19.78% of cases among children less than 5 years old (95% CI, 12.89%-26.66%) and 11.4% of cases in 2010-2012 (95% CI, 5.54%-17.28%).

CONCLUSIONS

Among children and adolescents, solid organ transplant recipients contribute a substantial fraction of NHL diagnoses, particularly DLBCL diagnoses. This fraction has increased over time. Prevention efforts targeted toward this group could reduce the overall pediatric NHL burden. Cancer 2017;123:4663-4671. © 2017 American Cancer Society.

18F-FDG PET for Detection of Primary Tracheobronchial T-/Natural Killer-Cell-Derived Posttransplant Lymphoproliferative Disorder After Lung Transplantation

Posttransplant lymphoproliferative disorder (PTLD) is a rare, but potentially devastating complication of solid organ transplantation. Epstein-Barr virus-associated PTLDs of T-cell origin are exceedingly rare. We present the case of a 20-year-old man with extranasal T-/natural killer-cell-derived PTLD after lung transplantation who underwent an F-FDG PET/CT scan for staging of disease. The F-FDG-PET scan demonstrated an unusual pattern of lymphomatous involvement limited to the recipients tracheobronchial tree without concomitant involvement of the donor's bronchi. This case highlights the potential of F-FDG PET/CT for sensitive detection and staging of uncommon manifestations of PTLD.

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

Background

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

Methods

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

Results

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

Conclusions

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

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.

Identification of distinct subgroups of EBV-positive post-transplant diffuse large B-cell lymphoma

Post-transplantation lymphoproliferative disorder is an aggressive complication of transplantation, most frequently of diffuse large B-cell lymphoma morphology and associated with Epstein-Barr virus (EBV) infection/reactivation. In this study the microenvironment of EBV⁺ (n=23) and EBV^- (n=9) post-transplant non-germinal center B-cell diffuse large B-cell lymphoma was characterized. Of EBV⁺ cases somatic hypermutation analysis, gene expression profiling, and extensive phenotyping were performed. Our results demonstrated variable cytotoxic T-cell infiltration and significantly increased CD163⁺ M2 macrophage infiltration in EBV⁺ compared with EBV^- post-transplant diffuse large B-cell lymphoma. On the basis of IgM staining and hypermutation analysis, two EBV⁺ post-transplant diffuse large B-cell lymphoma subgroups were identified: IgM⁺ tumors lacking somatic hypermutations and IgM^- tumors harboring somatic hypermutations. IgM^- tumors arose late following transplantation (median interval: 16 months), mainly in kidney recipients. IgM⁺ tumors on the other hand arose early (median interval: 3 months, P-value=0.0032), almost exclusively following stem cell transplantation and were associated with worse outcome (median survival 1 month for IgM⁺ versus 41 months for IgM^- tumors, log-rank/Wilcoxon P-value 0.07/0.04). Notably, IgM⁺ tumors were characterized by plasma cell features (monotypic kappa/lambda expression, high MUM1 expression, and partial CD138 expression) and a high proliferation index. Consistent with the plasma cell phenotype, unfolded protein response signaling was upregulated. In contrast, IgM^- EBV⁺ post-transplant diffuse large B-cell lymphoma did not express kappa, lambda, IgD, or CD138 and expressed limited MUM1. In these tumors T-cell signaling was enhanced associated with increased T-cell infiltration compared with IgM⁺ cases. Overall, our results allow further molecular classification of EBV⁺ post-transplant diffuse large B-cell lymphoma and provide a rationale for the use of subtype-specific-targeted therapies (eg, bortezomib in IgM⁺ tumors). Our findings also provide a biological basis for the clinical differences between post-transplant lymphoproliferative disorder following solid organ and stem cell transplantation, which are regarded as different disorders.

B-cell Lymphoproliferative Disorders Associated with Primary and Acquired Immunodeficiency

The diagnosis of lymphoproliferative disorders associated with immunodeficiency can be challenging because many of these conditions have overlapping clinical and pathologic features and share similarities with their counterparts in the immunocompetent setting. There are subtle but important differences between these conditions that are important to recognize for prognostic and therapeutic purposes. This article provides a clinicopathologic update on how understanding of these B-cell lymphoproliferations in immunodeficiency has evolved over the past decade.

EBV-negative monomorphic B-cell post-transplant lymphoproliferative disorders are pathologically distinct from EBV-positive cases and frequently contain TP53 mutations

Monomorphic post-transplant lymphoproliferative disorder commonly resembles diffuse large B-cell lymphoma or Burkitt lymphoma, and most are Epstein-Barr virus (EBV) positive. We retrospectively identified 32 cases of monomorphic post-transplant lymphoproliferative disorder from two institutions and evaluated EBV in situ hybridization; TP53 mutation status; p53, CD30, myc, and BCL2 expression by immunohistochemistry; proliferation index by Ki67; and germinal center vs non-germinal center immunophenotype by Hans criteria. Post-transplant lymphoproliferative disorder arose after hematopoietic stem cell transplant in five and solid organ transplant in 27 patients, a median of 4 and 96 months after transplant, respectively (overall median latency 71 months, range 2-295). The most common morphology was diffuse large B-cell lymphoma (28 cases), with three cases of Burkitt lymphoma, and one case of plasmablastic lymphoma. Ten cases (31%) were EBV negative. Of those with the morphology of diffuse large B-cell lymphoma, the EBV-negative cases were more frequently TP53-mutated (P<0.001), p53 positive by immunohistochemistry (P<0.001), CD30 negative (P<0.01), and of germinal center immunophenotype (P=0.01) compared with EBV-positive cases. No statistically significant difference in overall survival was identified based on EBV, TP53 mutation status, germinal center vs non-germinal center immunophenotype, or other immunohistochemical parameters evaluated. Patients who died of post-transplant lymphoproliferative disorder were older with a longer latency from time of transplant to diagnosis (P<0.05). Our study demonstrates that diffuse large B-cell lymphoma-related immunohistochemical prognostic markers have limited relevance in the post-transplant setting and underscores differences between EBV-positive and EBV-negative post-transplant lymphoproliferative disorder in terms of immunophenotype and TP53 mutation frequency, supporting an alternative pathogenesis for EBV-negative post-transplant lymphoproliferative disorder.

Recent insights in the pathogenesis of post-transplantation lymphoproliferative disorders

Post-transplant lymphoproliferative disorder (PTLD) is an aggressive complication of solid organ and hematopoietic stem cell transplantation that arises in up to 20% of transplant recipients. Infection or reactivation of the Epstein-Barr virus (EBV), a ubiquitous human herpesvirus, in combination with chronic immunosuppression are considered as the main predisposing factors, however insight in PTLD biology is fragmentary. The study of PTLD is complicated by its morphological heterogeneity and the lack of prospective trials, which also impede treatment optimization. Furthermore, the broad spectrum of underlying disorders and the graft type represent important confounding factors. PTLD encompasses different malignant subtypes that resemble histologically similar lymphomas in the general population. Post-transplant diffuse large B-cell lymphoma (PT-DLBCL), Burkitt lymphoma (PT-BL) and plasmablastic lymphoma (PT-PBL) occur most frequently. However, in many studies various EBV⁺ and EBV^- PTLD subtypes are pooled, complicating the interpretation of the results. In this review, studies of the gene expression pattern, the microenvironment and the genetic profile of PT-DLBCL, PT-BL and PT-PBL are summarized to better understand the mechanisms underlying post-transplantation lymphomagenesis. Based on the available findings we propose stratification of PTLD according to the histological subtype and the EBV status to facilitate the interpretation of future studies and the establishment of clinical trials.