Michael A. Nalesnik

REVERSIBILITY OF LYMPHOMAS AND LYMPHOPROLIFERATIVE LESIONS DEVELOPING UNDER CYCLOSPORIN-STEROID THERAPY

Post-transplant lymphomas or other lymphoproliferative lesions, which were usually associated with Epstein-Barr virus infections, developed in 8, 4, 3, and 2 recipients, respectively, of cadaveric kidney, liver, heart, and heart-lung homografts. Reduction or discontinuance of immunosuppression caused regression of the lesions, often without subsequent rejection of the grafts. Chemotherapy and irradiation were not valuable. The findings may influence policies about treating other kinds of post-transplantation neoplasms.

Tolerogenic immunosuppression for organ transplantation

BACKGROUND Insight into the mechanisms of organ engraftment and acquired tolerance has made it possible to facilitate these mechanisms, by tailoring the timing and dosage of immunosuppression in accordance with two therapeutic principles: recipient pretreatment, and minimum use of post-transplant immunosuppression. We aimed to apply these principles in recipients of renal and extrarenal organ transplants. METHODS 82 patients awaiting kidney, liver, pancreas, or intestinal transplantation were pretreated with about 5 mg/kg of a broadly reacting rabbit antithymocyte globulin during several hours. Post-transplant immunosuppression was restricted to tacrolimus unless additional drugs were needed to treat breakthrough rejection. After 4 months, patients on tacrolimus monotherapy were considered for dose-spacing to every other day or longer intervals. FINDINGS We frequently saw evidence of immune activation in graft biopsy samples, but unless this was associated with graft dysfunction or serious immune destruction, treatment usually was not intensified. Immunosuppression-related morbidity was virtually eliminated. 78 (95%) of 82 patients survived at 1 year and at 13-18 months. Graft survival was 73 (89%) of 82 at 1 year and 72 (88%) of 82 at 13-18 months. Of the 72 recipients with surviving grafts, 43 are on spaced doses of tacrolimus monotherapy: every other day (n=6), three times per week (11), twice per week (15), or once per week (11). INTERPRETATION The striking ability to wean immunosuppression in these recipients indicates variable induction of tolerance. The simple therapeutic principles are neither drug-specific nor organ-specific. Systematic application of these principles should allow improvements in quality of life and long-term survival after organ transplantation.

Epstein-Barr virus-induced posttransplant lymphoproliferative disorders

Epstein-Barr virus-induced posttransplant lymphoproliferative disease (EBV-PTLD) continues to be a major complication after solid organ transplantation in high-risk patients. Despite the identification of risk factors that predispose patients to develop EBV-PTLD, limitations in our knowledge of its pathogenesis, variable criteria for establishing the diagnosis, and lack of randomized studies addressing the prevention and treatment of EBV-PTLD hamper the optimal management of this transplant complication. This review summarizes the current knowledge of EBV-PTLD and, as a result of two separate international meetings on this topic, and provides recommendations for future areas of study.

THE FREQUENCY OF EPSTEIN-BARR VIRUS INFECTION AND ASSOCIATED LYMPHOPROLIFERATIVE SYNDROME AFTER TRANSPLANTATION AND ITS MANIFESTATIONS IN CHILDREN

Twenty cases of Epstein-Barr virus (EBV)-associated lymphoproliferative syndrome (LPS), defined by the presence of EBV nuclear antigen and/or EBV DNA in tissues, were diagnosed in 1467 transplant recipients in Pittsburgh from 1981–1985. The frequency of occurrence in pediatric transplant recipients was 4% (10/253), while in adults it was 0.8% (10/1214) (P < .0005). The frequency of LPS in adults declined after 1983 coincidental with the introduction of cyclosporine monitoring. However there was no apparent decline of LPS in children. We describe these ten pediatric cases and one additional case of LPS in a child who received her transplant before 1981. The frequency of EBV infection in 92 pediatric liver recipients was 63%. Of these subjects, 49% were seronegative and 77% of those acquired primary infection. Of 11 cases of pediatric EBV-associated LPS, 10 were in children who had primary infection shortly before or after transplantation. These results reinforce the importance of primary EBV infection in producing LPS, which was previously shown in adults. Children are at greater risk because they are more likely to be seronegative for EBV and to acquire primary infection. Three clinical types of LPS were recognized in children. The first (5 cases) was a self-limited mononucleo-sislike syndrome. The second syndrome (4 cases) began similarly, but then progressed over the next two months to widespread lymphoproliferation in internal organs and death. The third type (2 cases) was an extranodal intestinal monoclonal B cell lymphoma, occurring late after primary infection.

The Association of Epstein–Barr Virus with Smooth-Muscle Tumors Occurring after Organ Transplantation

BACKGROUND Epstein-Barr virus (EBV) has been associated with nasopharyngeal carcinoma, some lymphomas, and lymphoproliferative disease after organ transplantation. Many lymphoproliferative tumors that occur after transplantation are clonal, a property that classifies them as neoplastic. Clonality can be determined by analysis of the extrachromosomal circular DNA episomes produced by EBV infection. METHODS We describe three young children in whom smooth-muscle tumors developed 18 months to 5 1/2 years after liver transplantation with immunosuppression. We examined the tumors by microscopy and with immunohistochemical studies and molecular genetic analyses of the EBV DNA: RESULTS The tumors were composed of spindle cells with smooth-muscle features and resembled those described in patients with the acquired immunodeficiency syndrome. Immunohistochemical analysis was negative for EBV latent membrane protein and EBV receptor (CD21), but positive for EBV nuclear antigen 2. In situ hybridization revealed nuclear EBV sequences, and molecular genetic analysis showed the EBV genome to be clonal in all three patients. CONCLUSIONS Smooth-muscle tumors that developed after organ transplantation contained clonal EBV, suggesting that the virus has a role in the development of these neoplastic lesions.

Human Merkel cell polyomavirus infection I. MCV T antigen expression in Merkel cell carcinoma, lymphoid tissues and lymphoid tumors

Merkel cell polyomavirus (MCV) is a recently discovered human virus closely related to African green monkey lymphotropic polyomavirus. MCV DNA is integrated in ∼80% of Merkel cell carcinomas (MCC), a neuroendocrine skin cancer linked to lymphoid malignancies such as chronic lymphocytic leukemia (CLL). To assess MCV infection and its association with human diseases, we developed a monoclonal antibody that specifically recognizes endogenous and transfected MCV large T (LT) antigen. We show expression of MCV LT protein localized to nuclei of tumor cells from MCC having PCR quantified MCV genome at an average of 5.2 (range 0.8–14.3) T antigen DNA copies per cell. Expression of this putative viral oncoprotein in tumor cells provides the mechanistic underpinning supporting the notion that MCV causes a subset of MCC. In contrast, although 2.2% of 325 hematolymphoid malignancies surveyed also showed evidence for MCV infection by DNA PCR, none were positive at high viral copy numbers, and none of 173 lymphoid malignancies examined on tissue microarrays expressed MCV LT protein in tumor cells. As with some of the other human polyomaviruses, lymphocytes may serve as a tissue reservoir for MCV infection, but hematolymphoid malignancies associated with MCC are unlikely to be caused by MCV.

Report of a national conference on liver allocation in patients with hepatocellular carcinoma in the United States.

A national conference was held to better characterize the long‐term outcomes of liver transplantation (LT) for patients with hepatocellular carcinoma (HCC) and to assess whether it is justified to continue the policy of assigning increased priority for candidates with early‐stage HCC on the transplant waiting list in the United States. The objectives of the conference were to address specific HCC issues as they relate to liver allocation, develop a standardized pathology report form for the assessment of the explanted liver, develop more specific imaging criteria for HCC designed to qualify LT candidates for automatic Model for End‐Stage Liver Disease (MELD) exception points without the need for biopsy, and develop a standardized pretransplant imaging report form for the assessment of patients with liver lesions. At the completion of the meeting, there was agreement that the allocation policy should result in similar risks of removal from the waiting list and similar transplant rates for HCC and non‐HCC candidates. In addition, the allocation policy should select HCC candidates so that there are similar posttransplant outcomes for HCC and non‐HCC recipients. There was a general consensus for the development of a calculated continuous HCC priority score for ranking HCC candidates on the list that would incorporate the calculated MELD score, alpha‐fetoprotein, tumor size, and rate of tumor growth. Only candidates with at least stage T2 tumors would receive additional HCC priority points. Liver Transpl 16:262–278, 2010.

Epstein-Barr virus-negative post-transplant lymphoproliferative disorders: A distinct entity?

Post-transplant lymphoproliferative disorders (PTLDs) are usually but not invariably associated with Epstein-Barr virus (EBV). The reported incidence, however, of EBV-negative PTLDs varies widely, and it is uncertain whether they should be considered analogous to EBV-positive PTLDs and whether they have any distinctive features. Therefore, the EBV status of 133 PTLDs from 80 patients was determined using EBV-encoded small ribonucleic acid (EBER) in situ hybridization stains with or without Southern blot EBV terminal repeat analysis. The morphologic, immunophenotypic, genotypic, and clinical features of the EBV-negative PTLDs were reviewed, and selected features were compared with EBV-positive cases. Twenty-one percent of patients had at least one EBV-negative PTLD (14% of biopsies). The initial EBV-negative PTLDs occurred a median of 50 months post-transplantation compared with 10 months for EBV-positive cases. Although only 2% of PTLDs from before 1991 were EBV negative, 23% of subsequent PTLDs were EBV negative (p <0.001). Of the EBV-negative PTLDs, 67% were of monomorphic type (M-PTLD) compared with 42% of EBV-positive cases (p <0.05). The other EBV-negative PTLDs were of infectious mononucleosis-like, plasma cell-rich (n = 2), small B-cell lymphoid neoplasm, large granular lymphocyte disorder (n = 4) and polymorphic (P) types. B-cell clonality was established in 14 specimens and T-cell clonality was established in three (two patients). None of the remaining specimens were studied with Southern blot analysis and some had no ancillary studies. Rearrangement of c-MYC was identified in two M-PTLDs with small noncleaved-like features, and rearrangement of BCL-2 was found in one large noncleaved-like M-PTLD. Ten patients were alive at 3 to 63 months (only three patients received chemotherapy). Seven patients, all with M-PTLDs, are dead at 0.3 to 6 months. Therefore, EBV-negative PTLDs have distinct features, but some do respond to decreased immunosuppression, similar to EBV-positive cases, suggesting that EBV positivity should not be an absolute criterion for the diagnosis of a PTLD.

The diagnosis and treatment of posttransplant lymphoproliferative disorders.

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Carbon Monoxide Inhalation Protects Rat Intestinal Grafts from Ischemia/Reperfusion Injury

9.95. Second-class postage paid at Chicago, IL and additional mailing offices. All rights reseIved. No part of this publication may be reproduced, stored ill a retrieval system, or transmitted, in any form or by any means~electronic, mechanical, photocopying, recording, or otherwise~without prior written permission from the publisher except in cases described below. The code at the bottom of the first page in this issue indicates the publishers consent that copies of the article may be made for personal or internal use. This consent is given on the condition that the copier pay the stated per-copy fee through MA 01970) for copying beyond that permitted by Sections 107 or 108 of the United States Copyright Law. This consent does not extend to other kinds of copying, such as copying for general distribution, for advertising or promotional purposes, for creating new collected works, or for resale. India Current Problems in Surgery is listed in Index Medicus, Current Contents (CC), lSlIBioMed) and the SCI. FOREWORD Dr. Thomas Starzl and his colleagues have since their Colorado days spearheaded the recognition of the occurrence of posttransplant lymphoproliferative disorders and in a series of publications have contributed to their understanding and treatment. In this issue of Current Problems in Surgery, Drs. Nalesnik, Makowka, and Starzl have produced a superb and comprehensive monograph on this subject. The article is a tour de force of combined basic and clinical sciences, together with a concrete exposition of the various clinical factors involved from etiology, recognition, and treatment to ultimate outcome. As frightening as these disorders are, the heavy price they exact still turns out to be a tolerable price for the benefits of organ transplantation in the population at risk, particularly in view of the fact, as amply shown in these pages, that with appropriate therapy the tumors may be cured or made to regress, often without sacrifice of the transplanted organ. In what must be considered a complicated subject, much of it at the very forefront of our expanding knowledge in transplantation biology , the authors have created a lucid and readily comprehensible masterpiece. The clinical features of the disease are highlighted by …