Mucosa-associated lymphoid tissue-type lymphomas occurring in post-transplantation patients

Immune deficiency/dysregulation -associated lymphoproliferative disorders. Revised classification and management

Significant advances in the field of lymphoma have resulted in two recent classification proposals, the International Consensus Classification (ICC) and the 5th edition WHO. A few entities are categorized differently in the ICC compared to the WHO. Nowhere is this more apparent than the immunodeficiency lymphoproliferative disorders. The three previous versions of the WHO classification (3rd, 4th and revised 4th editions) and the ICC focused on four clinical settings in which these lesions arise for primary categorization. In contrast the 2023 WHO 5th edition includes pathologic characteristics including morphology and viral status, in addition to clinical setting, as important information for lesion classification. In addition, the 2023 WHO recognizes a broader number of clinical scenarios in which these lesions arise, including not only traditional types of immune deficiency but also immune dysregulation. With this classification it is hoped that new treatment strategies will be developed leading to better patient outcomes.

Epstein-Barr Virus-negative Marginal Zone Lymphoma as an Uncommon Form of Monomorphic Posttransplant Lymphoproliferative Disorder

Monomorphic posttransplant lymphoproliferative disorders have been defined as lymphoid or plasmacytic proliferations that fulfill criteria for one of the B-cell or T/NK-cell neoplasms recognized in immunocompetent hosts in the current WHO Classification. Low-grade B-cell neoplasms have historically been excluded from this category, although rare reports of marginal zone lymphoma (MZL) have been described. We report 9 cases of posttransplant Epstein-Barr virus-negative MZL, all arising in solid organ transplant recipients (4 renal, 3 liver, 1 cardiac, and 1 liver, pancreas, and small bowel). Seven were extranodal MZL of mucosa-associated lymphoid tissue type, all of which had gastrointestinal involvement (4 colon, 1 duodenum, 1 stomach, and 1 oropharynx/base of tongue). Notably, the preferential involvement of intestine distinguishes posttransplant extranodal MZL from sporadic cases. Immunoglobulin light-chain restriction was seen in all cases, with polymerase chain reaction showing a monoclonal pattern in 7 of 8 cases with successful amplification of polymerase chain reaction products. A clonally unrelated recurrence was seen in one case. Next-generation sequencing identified recurrent mutations previously reported in MZL in 3/5 cases. MZL was diagnosed at least 1 year after solid organ transplant (median time to presentation, 84 mo; range, 13 to 108 mo). The median age was 44 (range, 9 to 73 y); the male: female ratio was 5:4. The mean follow-up was 33.4 months, with an indolent clinical course observed. A subset responded to reduction in immunosuppression and anti-CD20 therapy alone. These data support the designation of Epstein-Barr virus-negative MZL as an uncommon form of monomorphic posttransplant lymphoproliferative disorders.

Colonic mucosa-associated lymphoid tissue in a renal transplant recipient: a case report

Background

Extra-gastric (particularly colonic) lymphoma of mucosa-associated lymphoid tissue in the immunosuppressed solid organ transplant recipient is rare. We report a case of low-volume mucosa-associated lymphoid tissue lymphoma with colonic and bone marrow involvement in a renal transplant recipient that has been managed conservatively.

Case presentation

A 62-year-old Caucasian man, 14 years after kidney transplantation, was diagnosed as having extra-nodal marginal zone lymphoma of mucosa-associated lymphoid tissue with bone marrow and colonic involvement, after a colonoscopy identified mucosa-associated lymphoid tissue lymphoma in a sessile sigmoid polyp following surveillance fecal occult blood testing that returned a positive result. A gastric biopsy showed no evidence of Helicobacter pylori, but Helicobacter pylori immunoglobulin G was positive. He received Helicobacter pylori eradication treatment and is being managed expectantly. Immunosuppression was unchanged with prednisolone, mycophenolate mofetil, and cyclosporine A. Renal allograft function has remained stable.

Conclusions

This case highlights the unexpected occurrence of colonic mucosa-associated lymphoid tissue lymphoma in a kidney transplant recipient. The case emphasizes the importance of histopathological diagnosis of colonic lesions in this patient cohort because the unusual diagnosis of low-volume mucosa-associated lymphoid tissue lymphoma can be managed expectantly as it does not appear to be clinically aggressive in the immunosuppressed solid organ transplant.

Expanding the Spectrum of EBV-positive Marginal Zone Lymphomas: A Lesion Associated With Diverse Immunodeficiency Settings

Traditionally low-grade B-cell lymphomas have been excluded from the category of monomorphic posttransplant lymphoproliferative disorders. However, recent reports identified Epstein-Barr virus-positive (EBV) extranodal marginal zone lymphomas (MZL), almost exclusively seen in the posttransplant setting. Some reported cases responded to reduced immunosuppression, suggesting that they should be considered as a form of posttransplant lymphoproliferative disorders. We identified 10 cases of EBV MZL, 9 in extranodal sites and 1 presenting in lymph node. Two cases arose following solid organ transplantation, but other settings included iatrogenic immunosuppression for rheumatoid arthritis (2); prior chemotherapy (2); congenital immune deficiency (1); and increased age (3), as the only potential cause of immune dysfunction. There were 4 males and 6 females; age range 18 to 86. The atypical plasmacytoid and/or monocytoid B cells were positive for EBV in all cases, with either latency I or II in all cases tested. Monotypic light chain expression was shown in all with 6 cases positive for IgG, and 2 for IgM, undetermined in 2. Clonal immunoglobulin gene rearrangement was positive in all cases with successful amplification. MYD88 L265P was wild type in the 6 cases tested. We show that EBV MZLs can arise in a variety of clinical settings, and are most often extranodal. Treatment varied, but most patients had clinically indolent disease with response to reduction of immune suppression, or immunochemotherapy.

Epstein-Barr Virus-Positive Extranodal Marginal Zone Lymphoma of Bronchial-Associated Lymphoid Tissue in the Posttransplant Setting: An Immunodeficiency-Related (Posttransplant) Lymphoproliferative Disorder?

OBJECTIVES

Posttransplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of hematolymphoid proliferations arising in the context of chronic immunosuppression. The common and indolent B-cell lymphomas, including extranodal marginal zone lymphomas (ENMZLs) of mucosa-associated lymphoid tissue (MALT), are excluded from the category of PTLD in the current World Health Organization classification.

METHODS

We report a case of Epstein-Barr virus (EBV)-positive bronchial-associated lymphoid tissue (BALT) lymphoma involving the lungs of a transplant patient.

RESULTS

Aside from history of cardiac transplant, young patient age, and EBV positivity, the histopathologic findings were indistinguishable from usual BALT lymphoma.

CONCLUSIONS

We review the literature of ENMZL occurring in immunocompromised patients and present this case for consideration that this specific entity is a PTLD. We believe that additional studies might lend strength to the hypothesis that this particular group of EBV-positive, posttransplant ENMZLs merits classification and management as PTLDs.

B-Cell and Classical Hodgkin Lymphomas Associated With Immunodeficiency: 2015 SH/EAHP Workshop Report-Part 2

OBJECTIVES

The 2015 Workshop of the Society for Hematopathology/European Association for Haematopathology submitted small and large B-cell lymphomas (BCLs), including classical Hodgkin lymphoma (CHL), in the context of immunodeficiency.

METHODS

Clinicopathologic and molecular features were studied to explore unifying concepts in malignant B-cell proliferations across immunodeficiency settings.

RESULTS

Cases submitted to the workshop spanned small BCLs presenting as nodal or extranodal marginal zone lymphoma and lymphoplasmacytic lymphoma, Epstein-Barr virus (EBV) positive in 75% of cases. Submitted large BCLs formed a spectrum from diffuse large B-cell lymphoma (DLBCL) to CHL across immunodeficiency settings. Additional studies demonstrated overexpression of PD-L1 and molecular 9p24 alterations in the large BCL spectrum and across different immunodeficiency settings.

CONCLUSIONS

Small BCLs occur in all immunodeficiency settings, and EBV positivity is essential for their recognition as immunodeficiency related. Large BCLs include a spectrum from DLBCL to CHL across all immunodeficiency settings; immunohistochemical and molecular features are suggestive of shared pathogenetic mechanisms involving PD-L1 immune checkpoints.

Adverse Drug Reactions in the Orofacial Region

A wide spectrum of drugs can sometimes give rise to numerous adverse orofacial manifestations, particularly dry mouth, taste disturbances, oral mucosal ulceration, and/or gingival swelling. There are few relevant randomized double-blind controlled studies in this field, and therefore this paper reviews the data from case reports, small series, and non-peer-reviewed reports of adverse drug reactions affecting the orofacial region (available from a MEDLINE search to April, 2003). The more common and significant adverse orofacial consequences of drug therapy are discussed.

Primary CNS lymphoproliferative disease, mycophenolate and calcineurin inhibitor usage

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

Atypical Marginal Zone Hyperplasia Is a Mimic for Lymphoma in Pediatric Transplant Recipients: Report of Two Patients

Atypical marginal zone hyperplasia (AMZH) of mucosa-associated lymphoid tissue (MALT) closely resembles lymphoma in that it shows expansion of the marginal zones with prominent intraepithelial B lymphocytes, is immunoglobulin light-chain restricted, and may show aberrant CD43 expression. However, unlike lymphoma, it does not show rearrangement of the immunoglobulin heavy chain gene (immunoglobulin H [IgH]) by polymerase chain reaction (PCR), and it behaves in a benign fashion. We identified AMZH in 2 pediatric solid organ transplant recipients who presented with adenotonsillar hypertrophy. To date, the patients have experienced a self-limited course in the absence of treatment or reduction of immunosuppression. Atypical marginal zone hyperplasia is a pitfall for posttransplant lymphoproliferative disorder and MALT lymphoma in the pediatric solid organ transplant population. In transplant patients with a lambda-restricted B-cell clone and marginal zone hyperplasia in native MALT sites, PCR for IgH and IgK gene rearrangement is essential to prevent misdiagnosis.

Automatic lymphoma classification with sentence subgraph mining from pathology reports

OBJECTIVE

Pathology reports are rich in narrative statements that encode a complex web of relations among medical concepts. These relations are routinely used by doctors to reason on diagnoses, but often require hand-crafted rules or supervised learning to extract into prespecified forms for computational disease modeling. We aim to automatically capture relations from narrative text without supervision.

METHODS

We design a novel framework that translates sentences into graph representations, automatically mines sentence subgraphs, reduces redundancy in mined subgraphs, and automatically generates subgraph features for subsequent classification tasks. To ensure meaningful interpretations over the sentence graphs, we use the Unified Medical Language System Metathesaurus to map token subsequences to concepts, and in turn sentence graph nodes. We test our system with multiple lymphoma classification tasks that together mimic the differential diagnosis by a pathologist. To this end, we prevent our classifiers from looking at explicit mentions or synonyms of lymphomas in the text.

RESULTS AND CONCLUSIONS

We compare our system with three baseline classifiers using standard n-grams, full MetaMap concepts, and filtered MetaMap concepts. Our system achieves high F-measures on multiple binary classifications of lymphoma (Burkitt lymphoma, 0.8; diffuse large B-cell lymphoma, 0.909; follicular lymphoma, 0.84; Hodgkin lymphoma, 0.912). Significance tests show that our system outperforms all three baselines. Moreover, feature analysis identifies subgraph features that contribute to improved performance; these features agree with the state-of-the-art knowledge about lymphoma classification. We also highlight how these unsupervised relation features may provide meaningful insights into lymphoma classification.

Epstein-barr virus-negative post-transplant lymphoproliferative diseases: three distinct cases from a single center

Three cases of Epstein-Barr virus (EBV)-negative post-transplant lymphoproliferative disease that occurred 6 to 8 years after renal transplantation are reported. The patients respectively had gastric mucosa-associated lymphoid tissue lymphoma, gastric diffuse large B-cell lymphoma, and atypical Burkitt lymphoma. Absence of EBV in the tissue samples was demonstrated by both in situ hybridization for EBV early RNA and polymerase chain reaction for EBV DNA. Patients were treated with reduction in immunosuppression and combined chemotherapy plus an anti-CD20 monoclonal antibody, rituximab. Despite the reduction in immunosuppression, patients had stable renal functions without loss of graft functions. The patient with atypical Burkitt lymphoma had an abnormal karyotype, did not respond to treatment completely, and died due to disease progression. The other patients are still alive and in remission 5 and 3 years after diagnosis, respectively. EBV-negative post-transplant lymphoproliferative diseases are usually late-onset and are reported to have poor prognosis. Thus, reduction in immunosuppression is usually not sufficient for treatment and more aggressive approaches like rituximab with combined chemotherapy are required.

EBV-positive low-grade marginal zone lymphoma in the breast with massive amyloid deposition arising in a heart transplant patient: A report of an unusual case

According to the 2008 World Health Organization classification, low-grade lymphomas arising in transplant recipients are not considered as specific types of PTLD. Most such cases are not associated with EBV infections, although rare reports of post-transplant marginal zone lymphoma have been described. We describe the case of an 18-yr-old female with history of heart transplant who developed a breast mass, but was otherwise completely asymptomatic. Surgical excision of the mass and histopathologic examination showed a low-grade B-cell lymphoma most consistent with marginal zone lymphoma with massive amyloid deposition; furthermore, numerous tumor cells were positive for EBV by in situ hybridization for EBV-encoded RNA. The patient was treated with reduction in immunosuppression, and no additional lesions developed. This case describes an atypical presentation of post-transplant low-grade B-cell lymphoma, unusual in its location, histopathologic features, and association with EBV, thereby adding to the rare previous accounts of such an entity, suggesting the need to include post-transplant marginal zone lymphomas in the current classification of PTLD, and helping in determining the optimal treatment modalities for such tumors.

Early onset, EBV− PTLD in pediatric liver-small bowel transplantation recipients: a spectrum of plasma cell neoplasms with favorable prognosis

Five cases of EBV− PTLD in pediatric recipients of combined liver and small bowel allografts are reported. The lesions were plasma cell neoplasms that resolved completely after minimal treatment.

Pulmonary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue associated with granulomatous inflammation in a child with chromosome 22q11.2 deletion syndrome (DiGeorge syndrome)

Patients with immunodeficiency disorders have an increased incidence of lymphoproliferative disorders; however, only 4 such patients with DiGeorge/chromosome 22q11.2 deletion syndrome have been reported. We report a case of a pulmonary Epstein-Barr virus-negative extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue in a child with this syndrome.

Managing post-transplant lymphoproliferative disorders in solid-organ transplant recipients: a review of immunosuppressant regimens

Post-transplant lymphoproliferative disorders (PTLD) are a heterogeneous group of potentially life-threatening complications that occur after solid organ and bone marrow transplantation. Risk factors for acquiring PTLD are type of organ transplanted, age, intensity of immunosuppression, viral infections such as Epstein-Barr virus (EBV) and time after transplantation. Due to a dearth of well designed prospective trials, treatment for PTLD is often empirical, with reduction in immunosuppression accepted as the first step. Rituximab, a monoclonal antibody directed against the CD20 antigen of immature B cells, is often used as monotherapy after reduction in immunosuppression, although this is associated with a high risk of relapse if patients have at least one of the following risk factors: age greater than 60 years, elevated lactate dehydrogenase levels and Eastern Cooperative Oncology Group Score between 2 and 4. For such patients, rituximab should be considered in combination with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone), particularly if high-grade PTLD is present. Although widely prescribed, the use of ganciclovir for PTLD remains controversial as EBV-transformed cells lack the thymidine kinase necessary for ganciclovir activation. Newer antivirals that combine ganciclovir with activators of cellular thymidine kinase have shown promising results in preclinical studies. In the absence of controlled trials, surgery may be indicated for localized disease and radiotherapy for patients with impending spinal cord compression or disease localized to the central nervous system or orbit. Future interventions may include adoptive immunotherapy, intravenous immunoglobulin, mammalian target of rapamycin inhibitors, monoclonal antibodies to interleukin-6 and galectin-1, and even EBV vaccination. Although several trials are in progress, it is necessary to wait for the long-term outcome of these studies on risk of PTLD relapse.

Orofacial diseases in solid organ and hematopoietic stem cell transplant recipients

OBJECTIVE

Solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients are at risk of several diseases, principally attributable to immunosuppression. This global overview of SOT/HSCT-associated orofacial diseases is aimed at providing a practical instrument for the oral healthcare management of SOT/HSCT recipients.

METHODS

Literature search was made through MEDLINE. The associations between orofacial diseases and SOT/HSCT were assessed using observational studies and case series and were classified into 'association', 'no association', and 'unclear association'.

RESULTS

Lip/oral cancers, drug-induced gingival overgrowth (DIGO), infections, including hairy leukoplakia and, less frequently, post-transplantation lymphoproliferative disorders (PTLDs) and oral lichenoid lesions of graft-versus-host disease (GVHD), were associated with SOT. Lip/oral cancers, GVHD, mucositis, DIGO, infections and, less frequently, PTLDs were associated with HSCT. Associations of orofacial granulomatosis-like lesions and oral mucosa-associated lymphoid tissue-type lymphoma with SOT, and of pyogenic granuloma and hairy leukoplakia with HSCT were unclear. Periodontal disease and dental caries were not associated with SOT/HSCT. For none of the local treatments was there a strong evidence of effectiveness.

CONCLUSIONS

Solid organ transplant/HSCT recipients are at risk of orofacial diseases. Adequate management of these patients alleviates local symptoms responsible for impaired eating, helps prevent systemic and lethal complications, and helps where dental healthcare has been neglected.

Diagnosis of post-transplant lymphoproliferative disorder in solid organ transplant recipients - BCSH and BTS Guidelines

A joint working group established by the Haemato-oncology subgroup of the British Committee for Standards in Haematology (BCSH) and the British Transplantation Society (BTS) has reviewed the available literature and made recommendations for the diagnosis and management of post-transplant lymphoproliferative disorder (PTLD) in adult recipients of solid organ transplants. This review details the risk factors predisposing to development, initial features and diagnosis. It is important that the risk of developing PTLD is considered when using post transplant immunosuppression and that the appropriate investigations are carried out when there are suspicions of the diagnosis. These must include tissue for histology and computed tomography scan to assess the extent of disease. These recommendations have been made primarily for adult patients, there have been some comments made with regard to paediatric practice.

Management of post-transplant lymphoproliferative disorder in adult solid organ transplant recipients - BCSH and BTS Guidelines

A joint working group established by the Haemato-oncology subgroup of the British Committee for Standards in Haematology (BCSH) and the British Transplantation Society (BTS) has reviewed the available literature and made recommendations for the diagnosis and management of post-transplant lymphoproliferative disorder in adult recipients of solid organ transplants. This review details the therapeutic options recommended including reduction in immunosuppression (RIS), transplant organ resection, radiotherapy and chemotherapy. Effective therapy should be instituted before progressive disease results in declining performance status and multi-organ dysfunction. The goal of treatment should be a durable complete remission with retention of transplanted organ function with minimal toxicity.

Extramedullary plasmacytoma-like posttransplantation lymphoproliferative disorders: clinical and pathologic features

Most monomorphic posttransplantation lymphoproliferative disorders (PTLDs) resemble diffuse large B-cell lymphoma or Burkitt lymphoma. Rare cases of PTLD resembling extramedullary plasmacytomas have also been described. This report describes the clinical, histologic, phenotypic, and genotypic findings in 4 cases of plasmacytoma-like PTLD (2 nodal, 1 adenoidal, and 1 cutaneous) and compares the findings with extramedullary involvement by plasma cell neoplasms arising in immunocompetent patients. Plasmacytoma-like PTLDs characteristically arise late after transplantation (mean, 7.0 years), show a variable association with Epstein-Barr virus (2/4 cases positive), and demonstrate histologic and phenotypic findings that overlap with immunocompetent extramedullary plasma cell neoplasms. None of the patients with plasmacytoma-like PTLD developed lytic bone lesions, and 3 of 4 patients had complete responses (>2 years) to reduction of immunosuppression, confirming the role of immunosuppression in the pathogenesis of these lesions. This report, which represents the first case series of plasmacytoma-like PTLD, clarifies the features of this rare subtype of PTLD.

Development of hairy cell leukemia in a patient after cardiac transplantation

Post-transplant lymphoproliferative disorders (PTLDs) are well-recognized complications of bone marrow and solid organ transplantation, comprising a heterogenous group of lymphoproliferations with a spectrum of morphologic, phenotypic and molecular features. Although PTLDs are usually Epstein-Barr virus-driven B-cell lymphoproliferations, T/natural killer-cell lymphoproliferations, multiple myeloma, and Hodgkin's lymphoma are also recognized as part of the PTLD spectrum. Hairy cell leukemia, a low-grade B-cell lymphoproliferation, has not been recognized as part of the PTLD spectrum. We report the first case of hairy cell leukemia occurring after cardiac transplantation. It is unclear whether this case, similar to other cases of low-grade B-cell lymphoproliferations reported after transplantation, is related to immunosuppression and therefore part of the spectrum of PTLDs, or merely represents coincidental event occurring in an immunocompromised patient.

Gastric hyperplastic polyps in post transplant patients: a clinicopathologic study

Gastric hyperplastic polyps in organ transplant recipients have been recently described; however, the clinical significance of hyperplastic polyps in this setting remains unclear. The aim of this study is to further characterize the clinical presentation and histopathology of gastric hyperplastic polyps in organ transplant recipients as compared to hyperplastic polyps in non-transplant individuals. All gastric hyperplastic polyps diagnosed in our institute from 1999 to 2005 were retrieved. Clinical data including endoscopic findings were reviewed. Twenty cases without history of transplantation were randomly selected for a control population. Hematoxylin and eosin and Genta stains were reviewed. 104 cases of gastric hyperplastic polyps were identified. Sixteen (15%) had a history of solid organ (one liver/kidney, four livers, one lung, one kidney, one kidney/pancreas, three hearts) or bone marrow transplantation (five). The average time after transplantation was 28 months. Signs/symptoms leading to endoscopy were more frequently nausea/vomiting in transplant patients as compared to bleeding/hematemesis/anemia in non-transplant patients. The transplant patients tended to be younger with a reversed M:F ratio, but age was the only demographic factor that was statistically significant. There was no difference in polyp size, location and number. Histologically, no difference was observed in the frequency of active inflammation, Helicobacter pylori infection or intestinal metaplasia. Dysplasia was not present in any of the cases. None of the patients had a history of polyposis syndrome. In conclusion, a significant percentage of gastric hyperplastic polyps (15%) were from organ transplant patients, further suggesting a strong association of gastric hyperplastic polyps with transplantation. The younger age in the transplant group may be explained by the nature of the cohort qualified for transplantation. While no statistically significant differences in histopathologic features were found between transplant and non-transplant groups, analysis was limited by small case numbers. Overall, gastric hyperplastic polyps in the post transplant setting is a common, but under-recognized entity and merits further clinicopathologic analysis.

Extranodal lymphoma

Lymphomas arising in extranodal sites are intriguing. The types of lymphomas encountered vary widely from one extranodal site to another. For many types of extranodal lymphomas, there are distinctive clinicopathologic features, sometimes including association with an underlying immunodeficiency syndrome, autoimmune disease, infection, or other immunologic disorder, or a predilection to affect patients of certain ethnic origins. Presented below is a review of lymphomas that are encountered most often in extranodal sites.

Gene expression profiling of Epstein-Barr virus-positive and -negative monomorphic B-cell posttransplant lymphoproliferative disorders

Although most posttransplant lymphoproliferative disorders (PTLD) are related to Epstein-Barr virus (EBV) infection, approximately 20% lack detectable EBV (EBV-). It is uncertain whether the latter cases are truly distinct from EBV+ PTLD or possibly relate to another infectious agent. This study used gene expression profiling to further investigate the relationship between EBV+ and EBV- monomorphic B-cell PTLD, and to search for clues to their pathogenesis. Affymetrix HU133A GeneChips were used to compare 4 EBV+ and 4 EBV- cases of monomorphic B-cell PTLD. Hierarchical clustering successfully distinguished the EBV+ and EBV- groups. Relative to EBV- PTLD, 54 transcripts were over-expressed in EBV+ PTLD. The transcripts identified included IRF7 (a known regulator of EBV LMP1 expression), EBI2 (EBV-induced gene 2), and 3 that are interferon induced (MX1, IFITM1, and IFITM3). In addition, the EBV+ group contained 232 transcripts decreased relative to the EBV- group, including changes concordant with those previously reported after EBV infection of cultured B-cell lines. In summary, in a small group of monomorphic B-cell PTLD, EBV+ cases demonstrated a subset of gene expression changes associated with EBV infection of B cells. By contrast, EBV- PTLD lacked viral-associated changes suggesting that they are biologically distinct.

The clinicopathologic spectrum of posttransplantation lymphoproliferative disorders

CONTEXT

Posttransplantation lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid proliferations occurring in the setting of solid organ or bone marrow transplantation. They show a clinical, morphologic, and molecular genetic spectrum ranging from reactive polyclonal lesions to frank lymphomas. The close association with Epstein-Barr virus has been established and the pathogenetic role of this virus is becoming better understood. Although they are relatively uncommon, PTLDs are a significant cause of morbidity and mortality in transplant patients.

OBJECTIVE

To review the incidence, risk factors, clinical features, pathogenesis, and classification of PTLDs.

DATA SOURCES

We reviewed relevant articles indexed in PubMed (National Library of Medicine), with emphasis on more recent studies. The classification of PTLDs is based on the most current World Health Organization classification text.

CONCLUSIONS

Posttransplantation lymphoproliferative disorders are a heterogeneous group of disorders showing a wide clinical and morphologic spectrum. Although relatively uncommon, PTLDs represent a serious complication after transplantation. Many risk factors for PTLD are well established, including transplanted organ, age at transplant, and Epstein-Barr virus seronegativity at transplant. However, other factors have been implicated and still require additional examination. Recent studies are shedding some light on the pathogenesis of PTLDs and defining relevant pathways related to Epstein-Barr virus. As the pathogenesis of PTLDs is further elucidated, the classification of PTLDs will most likely evolve.

Primary cutaneous marginal zone B-cell lymphoma of MALT type in a child

Marginal zone B-cell lymphoma (MZBCL) of mucosa-associated lymphoid tissue type is a peculiar variant of B-cell neoplasm showing distinct clinical and pathologic features. Its occurrence in children or adolescents is extremely uncommon. We describe the case of an 11-year-old boy who developed such a lymphomatous process involving primarily the skin. The tumor was characterized by a maturing plasma cell population that included immunoblasts, heavy-chain but not light-chain restriction suggestive of monoclonality, and a prevalent, focally granulomatous component of histiocytes. As an additional interesting feature, a trisomy 3 was demonstrated by fluorescence in situ hybridization analysis. The clinical, morphological, phenotypic, and genetic characteristics seen in our patient do not differ significantly from those described in primary cutaneous MZBCL occurring in adults.

Remission of primary low-grade gastric lymphomas of the mucosa-associated lymphoid tissue type in immunocompromised pediatric patients

We report the remission of primary gastric lymphoma of the mucosa-associated lymphoid tissue (MALT) type in two immunocompromised pediatric patients. Patient 1, a 14-year-old boy in an immunocompromised state of unknown cause, complained of repeated abdominal pain. Examinations revealed gastric MALT with local invasion and lymph node involvement. Serum anti-Helicobacter pylori (H pylori) antibody was positive. H pylori eradication was abandoned due to its adverse effects. The MALT lesion spontaneously regressed over the next 24 months without any treatment for lymphoma. Patient 2, a 6-year-old boy, underwent cord blood transplantation for the treatment of adrenoleukodystrophy. He was administered immunosuppressants for graft-versus-host disease after transplantation. Nausea and hematochezia appeared and further examinations revealed gastric MALT with H pylori gastritis. Treatment consisting of medication for the H pylori infection alone eradicated the H pylori and completely resolved the patient’s MALT lesion, as well. Patients 1 and 2 were followed up over periods of 10 years and 3 years, respectively, without any signs of relapse. In conclusion, gastric lymphoma of the MALT type can be cured by conservative treatment even in immunocompromised pediatric patients.

Incidence of cancer after immunosuppressive treatment for heart transplantation

Prolonged or intensive immunosuppressive therapy used after organ transplantation is complicated by an increased incidence of cancer. Striking differences in incidence are observed in heart and heart-lung transplant recipients when compared with renal transplant patients. The most significant increase was in the incidence of lymphomas in cardiac versus renal patients. Moreover, a two-fold greater increase of all neoplasms was found in cardiac recipients, with nearly a six-fold increase in visceral tumors. Several factors may account for these differences. In cardiac allograft recipients, intensive immunosuppression is frequently used to reverse acute rejection and the highest number of cardiac transplants was performed in the era of polypharmacy, usually consisting of triple therapy.

Gastrointestinal complications in renal transplant recipients

Gastrointestinal complications are frequent in renal transplant recipients and can include oral lesions, esophagitis, peptic ulcer, diarrhea, colon disorders and malignancy. Oral lesions may be caused by drugs such as cyclosporine and sirolimus, by virus or fungal infections. Leukoplakia may develop in patients with Epstein-Barr virus (EBV) infection. The commonest esophageal disorder is represented by fungal esophagitis usually caused by candida. A number of patients may suffer from nausea, vomiting and gastric discomfort. These disorders are more frequent in patients treated with mycophenolate mofetil (MMF). Peptic ulcer is more rare than in the past. Patients with a history of peptic ulcer are particularly prone to this complication. Other gastroduodenal disorders are caused by cytomegalovirus (CMV) and herpes simplex infection. Diarrhea is a frequent disorder which may be caused by pathogen microorganisms or by immunosuppressive agents. The differential diagnosis may be difficult. Colon disorders mainly consist of hemorrhage, usually sustained by CMV infection, or perforation which may be caused by diverticulitis or intestinal ischemia. Colon cancer, anal carcinoma, and EBV-associated lymphoproliferative disorders are particularly frequent in transplant recipients. A particular gastric lymphoma called mucosa-associated lymphoid tissue (MALT) lymphoma may develop in renal transplant patients. It usually responds to the eradication of Helicobacter pylori.

Prenatal genotyping of RHD and SRY using maternal blood

BACKGROUND AND OBJECTIVES

The aim of the study was to perform fetal RHD genotyping in maternal plasma using a fluorescent polymerase chain reaction (PCR) technique. Duplex PCR, amplifying RHD and SRY in the same tube, was undertaken. The effect of varying storage temperatures on the concentration of fetal DNA was investigated in a separate study involving 10 RhD-negative pregnant women.

MATERIALS AND METHODS

Primers and probes for the RHD gene's exon 7 and the sex-determining region, Y, were designed, and monoplex and duplex PCR were performed. Blood samples from 10 RhD-negative women were split into four and treated in four different ways before measuring the concentration of fetal DNA by quantitative PCR.

RESULTS

DNA extracted from the plasma of 114 RhD-negative pregnant women was tested for the presence of fetal RHD. The discrepancy between genotyping and serological RhD typing of the babies postpartum was 8% when counting one positive replicate as a positive result. Duplex PCR, amplifying RHD and SRY in the same tube, showed a reduced sensitivity for amplification of the SRY gene segment. There was a statistically significant reduction of fetal DNA in blood samples stored at room temperature for 48 h compared with the same sample stored at a temperature of <10 degrees C for the same length of time.

CONCLUSIONS

This method is not suitable for routine analysis because of the lack of a positive control for RHD-negative female fetuses and a decrease in PCR sensitivity when performing duplex PCR. Fetal DNA in maternal plasma is better preserved when the blood sample is kept cool.

Burkitt lymphoma arising in organ transplant recipients: a clinicopathologic study of five cases

We report five cases of Burkitt lymphoma arising in organ transplant recipients. There were four men and one woman with a mean age of 35 years. All were solid organ recipients with three renal, one liver, and one double lung transplantation. The time interval between organ transplantation and lymphoma averaged 4.5 years. Patients typically presented with high-stage disease with generalized lymphadenopathy and bone marrow involvement. Histology showed classic Burkitt lymphoma or atypical variant/Burkitt-like morphology. C-MYC rearrangement, including three cases with immunoglobulin heavy chain and two cases with lambda light chain, and Epstein-Barr virus were detected in all the cases. Additional chromosomal abnormalities were present in two of three cases and p53 mutation was found in one of three cases. Aberrant genotype and phenotype were frequently encountered, including minor monoclonal or oligoclonal T-cell populations and undetectable surface immunoglobulin light chain expression. Four patients received antilymphoma regimens, with combination chemotherapy (three patients) and/or Rituximab (three patients), in addition to reduction of immunosuppression. All four patients achieved complete remission. We conclude that posttransplant Burkitt lymphoma represents a characteristic clinicopathologic entity and occurs later after transplantation. Genotypic and phenotypic aberrations are often present. Rituximab may be an effective alternative to conventional combination chemotherapy in the treatment of a posttransplant Burkitt lymphoma.

MALToma: a Helicobacter pylori-associated malignancy in transplant patients: a report from the Israel Penn International Transplant Tumor Registry with a review of published literature

BACKGROUND

Mucosa-associated lymphoid tissue lymphoma (MALToma) is a Helicobacter pylori-related tumor of B-cell origin, the malignant potential for which remains to be defined in immunosuppressed patients.

METHODS

Review of the Israel Penn International Transplant Tumor Registry identified six cases of gastric MALToma. Patient demographics, management, and outcomes were compared and published literature was reviewed.

RESULTS

MALToma developed in six transplant recipients (three kidney, two heart, one kidney-pancreas). All were treated with immunosuppression minimization and therapy for H. pylori, resulting in disease regression in five patients. One patient developed progression to high-grade MALToma despite documented H. pylori eradication, required surgery and chemotherapy, and died, with significant disease at autopsy.

CONCLUSIONS

Treatment of MALToma with immunosuppression minimization and anti-H. pylori therapy results in a majority of patients becoming disease free. Observation of malignant degeneration into an aggressive, high-grade lymphoma in one patient indicates the malignant potential. Diligent follow-up of these patients with endoscopy and biopsy is therefore indicated.

Liver transplantation in the UK

INTRODUCTION

This paper provides a review of the practice of liver transplantation with the main emphasis on UK practice and indications for transplantation.

REFERRAL AND ASSESSMENT

This section reviews the process of referral and assessment of patients with liver disease with reference to UK practice.

DONOR ORGANS

The practice of brainstem death and cadaveric organ donation is peculiar to individual countries and rates of donation and potential areas of improvement are addressed.

OPERATIVE TECHNIQUE

The technical innovations that have led to liver transplantation becoming a semi-elective procedure are reviewed. Specific emphasis is made to the role of liver reduction and splitting and living related liver transplantation and how this impacts on UK practice are reviewed. The complications of liver transplan-tation are also reviewed with reference to our own unit. Immunosuppression:The evolution of immunosuppression and its impact on liver transplantation are reviewed with some reference to future protocols.

RETRANSPLANTATION

The role of retransplantation is reviewed.

OUTCOME AND SURVIVAL

The results of liver transplantation are reviewed with specific emphasis on our own experience.

FUTURE

The future of liver transplantation is addressed.

Clinicopathologic characteristics of post-transplant lymphoproliferative disorders

Post-transplant lymphoproliferative disorder (PTLD) is a syndrome of uncontrolled lymphoid growth in the immunosuppressed transplant patient. Known risk factors include Epstein-Barr virus (EBV) seronegativity at the time of transplant, pediatric age and allograft type. Newer studies suggest that constitutional factors such as cytokine gene polymorphisms may also predispose to PTLD. Although PTLD may occur at any time, the majority of cases arise within the first two post-transplant years. Clinical presentation is heterogeneous and dependent upon the location and extent of disease. Allograft involvement is common, particularly in cases of lung, intestine, or pancreas transplantation. Most PTLD are of B lymphocyte origin. A histopathologic classification system has been proposed and it is important to understand the histology of these lesions, since the term PTLD incorporates both hyperplastic and neoplastic growths. Histologic subclassification also has prognostic value, although this remains imperfect at present. Clinical evaluation should include staging as for lymphomas, since PTLD stage is an important determinant of outcome. In EBV-associated PTLD, quantitative evaluation of EB viral genomic load has a role in guiding prophylaxis, diagnosis, and monitoring of therapy. The presence of EBV is not an absolute requirement for the diagnosis of PTLD, and it has been suggested that there has been a recent increase in the number of EBV-negative cases. Such lesions have a median onset time around 50-60 months post-transplant. Therapy of PTLD must be tailored to the individual patient. Newer modalities such as anti-CD20 antibodies are being evaluated and may complement the standard stepwise approach that begins with a reduction of immunosuppression. The role of chemotherapy continues to be defined, and in some cases early recourse to this approach may be desirable. Survival varies by age and extent of disease, with pediatric patients and those with localized disease tending to fare better. A finer understanding of the molecular cellular and virologic underpinnings of PTLD remains essential in order to define optimal treatment regimens. The emergence of EBV-negative PTLD is a problem and the relationship of this to standard lymphomas arising in nonimmunosuppressed patients remains to be defined. Continued individual and multi-institutional studies are essential for progress in these areas.

Post-transplant lymphoproliferative disorders: T-cell lymphoma following cardiac transplant

Post-transplant lymphoproliferative disorders (PTLD) are a frequently fatal complication occurring after transplant. The majority of cases are of B-cell origin but a smaller percentage of cases are of T-cell origin. The etiology of these disorders is unclear, however, EBV (Epstein-Barr virus) in the context of immunosuppression is thought to play a role, particularly in B-cell PTLD. We report a case of T-cell PTLD limited to the bone marrow occurring eight years post-cardiac transplantation and review the literature on T-cell PTLD after heart transplant.

Influence of host-recipient origin on clinical aspects of posttransplantation lymphoproliferative disorders in kidney transplantation

BACKGROUND

Posttransplantation lymphoproliferative disorder (PTLD) is a well-known complication of immunosuppression associated with solid organ transplantation. The donor or host origin of PTLD may influence the outcome of the disease as it has been reported that a donor origin may be associated with a better prognosis. The aim of the study was to determine the origin (recipient or donor) of 12 PTLD occurring in kidney transplant recipients and to correlate the results with clinical findings.

METHODS

Origin of PTLD was determined using HLA DRB1 molecular typing, analysis of multiple short-tandem repeat microsatellite loci, and HLA class I antigen expression by immunohistochemistry.

RESULTS

Combining the three techniques, we found that eight cases originated from the recipient and four cases originated from the donor. The results of the three techniques were concordant and altogether assigned the origin of the tumors. All the donor-origin PTLD were strictly localized to the kidney graft, developed after a mean time of 5 months after transplantation, and regressed after reduction of immunosuppression. In contrast, seven of the eight recipient-origin PTLD presented as multisystemic disease, occurred a mean time of 75.7 months after the transplantation, and had a worse outcome (mortality, five deaths of eight patients, 62.5%).

CONCLUSIONS

These results suggest that PTLD originating from the donor arise in the first year after transplantation into the graft, and that recipient-origin PTLD develop later as an invasive disease. Because it permits simultaneously the analysis of cell morphology and tumor origin, immunohistochemistry is a more reliable technique in the case of graft tumors associated with allograft rejection. The determination of the origin of the tumors seems to be of value in the management of PTLD to predict the outcome and to adapt therapy.