Epstein-Barr virus-induced posttransplant lymphoproliferative disorders. ASTS/ASTP EBV-PTLD Task Force and The Mayo Clinic Organized International Consensus Development Meeting

Presentation and early detection of post-transplant lymphoproliferative disorder after solid organ transplantation

Post-transplant lymphoproliferative disorder (PTLD) is a serious and still frequently observed complication of solid organ transplantation. Despite the recent introduction of anti B-cell monoclonal antibody therapy (rituximab) for treatment of PTLD, mortality rates remain high. Because PTLD often presents in a nonspecific way in clinically unsuspected patients, it is a major challenge to diagnose PTLD at an early stage. Epstein-Barr virus (EBV)-DNA load monitoring is a promising tool for the identification of patients at risk for PTLD development. However, there are some limitations of this method, and not all patients at risk for PTLD can be identified by EBV-DNA measurements alone. Therefore, it is of major importance to recognize early clinical signs and symptoms of PTLD. In this review, risk factors for PTLD development, disease presentation, and methods for early detection will be discussed. Special attention is given to allograft and digestive tract localization and the relation with time of onset of PTLD. The value and pitfalls of EBV-DNA load monitoring are discussed. In addition, because fluorodeoxyglucose (FDG)-positron emission tomography (PET) has shown to be a powerful tool for staging and response evaluation of malignant lymphoma, the role of FDG-PET for early diagnosis and staging of PTLD is addressed.

Sustained Epstein-Barr virus detection in paediatric liver transplantation. Insights into the occurrence of late PTLD

Epstein-Barr virus (EBV) infection is the main cause of post-transplant lymphoproliferative disease (PTLD). Little is known on chronic carrier state and its relation with late PTLD. We aimed to study EBV infection in the long-term after paediatric liver transplantation (OLT). We conducted a retrospective review of 34 children monitored for a median of 5.8 years (range 1.5-17.7). 21 were IgG seronegative (group A) and 13 seropositive (group B) before OLT. Primary infection was the appearance of VCA-IgM or VCA-IgG or Real-Time Polymerase Chain Reaction (RT-PCR) in patients previously IgG seronegative; positive VCA-IgM or EA-IgG or RT-PCR lasting longer than 6 months was defined sustained viral detection (SVD). 18/21 patients of group A had a primary infection at a median time of 3 months after transplant (0.5-60). 14/18 of group A and 0/13 of group B had a SVD (P < 0.0001). Viral loads greater than 500 copies/10(5) mononuclear cells occurred in 12/18 patients in group A and 0/13 patients in group B (P < 0.0001). The 3 patients who developed late PTLD (median time after OLT 47 months, range 15-121) were from group A, and presented with SVD before developing PTLD. In conclusion, EBV infection in seronegative patients at OLT is associated with greater viral loads and sustained viral detection. Late PTLD occurred only in naïve patients with markers of SVD. Three to 4 monthly long-term monitoring of EBV in pre-OLT naïve patients might help preventing the occurrence of late PTLD.

Posttransplant Hodgkin lymphoma preceded by polymorphic posttransplant lymphoproliferative disorder: report of a pediatric case and review of the literature

Epstein-Barr virus-mediated posttransplant lymphoproliferative disorder (PTLD) is a well-recognized complication of immunosuppression in transplant patients and has broad clinical manifestations and pathologic features ranging from reactive lymphoid proliferation to malignant lymphoma. The category of Hodgkin lymphoma and Hodgkin lymphomalike PTLD is an uncommon variant of PTLD. Development of Hodgkin lymphoma subsequent to other subtypes of PTLD in the same patient is even more unusual, especially in pediatric patients. In this report, we describe a pediatric case of Epstein-Barr virus-associated posttransplant Hodgkin lymphoma developing several years after the patient was diagnosed with polymorphic PTLD and review the literature of the previously reported cases in children to further help characterize the clinical features, histopathologic appearances, biology, and treatment strategies of this uncommon entity.

Review article: medical management of the liver transplant recipient - a primer for non-transplant doctors

BACKGROUND

Survival 10 years after orthotopic liver transplantation now approaches 65%. Consequently, community doctors must manage the metabolic and neoplastic complications of orthotopic liver transplantation in an ageing population.

AIMS

To review common sources of morbidity and mortality in long-term orthotopic liver transplantation recipients, and to make evidence-based recommendations regarding their management.

METHODS

Pertinent studies and reviews were identified by literature search through PubMed. Where evidence-based recommendations could not be gleaned from the literature, expert opinion was obtained from syllabi of national meetings.

RESULTS

The two most common causes of morbidity and mortality in orthotopic liver transplantation recipients are atherosclerotic vascular disease and de novo malignancy. The pathogenesis of many complications begins before orthotopic liver transplantation, and many are potentially modifiable. Most complications, however, can be directly ascribed to immunosuppressive agents. Despite improvements in our understanding of the pathogenesis and epidemiology of the metabolic and neoplastic complications of orthotopic liver transplantation, remarkably few randomized-controlled studies exist to define their optimal management.

CONCLUSIONS

Orthotopic liver transplantation recipients experience and succumb to the same afflictions of old age as non-transplant patients, but with greater frequency and at an earlier age. Most recommendations regarding surveillance for, and treatment of, medical complications of orthotopic liver transplantation remain based upon expert opinion rather than evidence-based medicine.

Impact of Epstein-Barr virus in monomorphic B-cell posttransplant lymphoproliferative disorders: a histogenetic study

The heterogeneity of the posttransplant lymphoproliferative disorders (PTLDs) is well recognized. However, in contrast to other immunodeficiency-associated lymphomas or diffuse large B-cell lymphomas in general, studies of the histogenetic spectrum of the large category of monomorphic B-cell cases have been more limited, produced conflicting results, and have paid little attention to the impact of Epstein-Barr virus (EBV). Therefore, 30 monomorphic B-cell PTLD from 27 patients were analyzed using EBER in situ hybridization for EBV and a panel of antibodies directed against CD20, CD3/bcl-6, CD10, MUM-1/IRF4, CD138, and bcl-2. The results were correlated with the histopathologic features and clinical outcome. All PTLD were CD20 with 23% CD10, 53% bcl-6, 67% MUM-1/IRF4, 13% CD138, 83% bcl-2 and 67% EBV. 30% of the PTLD had a germinal center (GC) profile (CD10, bcl-6, MUM-1/IRF4, CD138), 53% a "late GC/early post-GC" profile (CD10, bcl-6, MUM-1/IRF4, CD138), 13% a post-GC profile (CD10, bcl-6, MUM-1/IRF4, CD138) and 3% an indeterminate profile (all markers negative). EBV positivity was associated with MUM-1/IRF4 expression (P=0.005) and with a non-GC phenotype (P=0.01). All CD138 cases were EBV. The cases with a GC phenotype were the most likely to resemble transformed GC cells (P=0.023). No statistically significant survival differences could be documented between those with a GC versus non-GC phenotype. These results highlight the broad histogenetic spectrum of monomorphic B-cell PTLD. They demonstrate the association of EBV positivity with a non-GC phenotype and suggest that EBV PTLD are more like lymphomas that arise in immunocompetent individuals. The lack of a demonstrable correlation with survival may relate to the relatively small number of cases studied.

Nierentransplantation

Die Nierentransplantation ist die effektivste Behandlungsmethode der chronischen terminalen Niereninsuffizienz. Seit den 1960er Jahren entwickelte sie sich zu einer Standardtherapie. Wichtige Voraussetzungen waren die Entdeckung des HLA-Systems, die Entwicklung der Immunsuppressiva sowie die technische Perfektionierung des Organerhaltes außerhalb eines lebenden Körpers. Die 5-Jahres-Überlebensrate für Allotransplantate beträgt etwa 65%, diejenige von Lebendspenden 79%.

Opportunistic infections in 547 organ transplant recipients receiving alemtuzumab, a humanized monoclonal CD-52 antibody

BACKGROUND

Alemtuzumab is being increasingly used for the prevention and/or treatment of acute allograft rejection in organ transplant recipients. We assessed the risks of infection in, to our knowledge, the largest cohort and broadest range of organ transplant recipients yet reported to have received alemtuzumab.

METHODS

All patients who received alemtuzumab from September 2002 through March 2004, either as induction therapy at the time of transplantation or for the treatment of rejection, were evaluated for the development of an opportunistic infection (OI) until death or for 12 months after receipt of the last dose of alemtuzumab.

RESULTS

A total of 547 recipients were included, 65% of whom received alemtuzumab for induction therapy only. Overall, 56 recipients (10%) developed 62 OIs, including cytomegalovirus disease (n = 16), BK virus infection (n=12), posttransplantation lymphoproliferative disease (n=5), human herpesvirus 6 infection (n=1), parvovirus infection (n=1), esophageal candidiasis (n=12), cryptococcosis (n=2), invasive mold infection (n=4), Nocardia infection (n=4), mycobacterial infection (n=3), Balamuthia mandrillaris infection (n=1), and toxoplasmosis (n=1). Patients who received alemtuzumab for induction therapy were significantly less likely to develop an OI, compared with patients who received alemtuzumab for rejection therapy (4.5% vs. 21%; P<.001). Independent predictors of the development of an OI were administration of alemtuzumab for rejection therapy (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.8-6.8; P<.001), allograft failure (OR, 2.1; 95% CI, 1.1-4.4; P=.04), and receipt of a lung transplant (OR, 3.7; 95% CI, 1.7-8.0; P=.001) or an intestinal transplant (OR, 8.3; 95% CI, 3.5-19.5; P<.001).

CONCLUSIONS

Patients who received alemtuzumab for the treatment of allograft rejection were significantly more likely to develop an OI, compared with patients who received alemtuzumab for induction therapy only. Such data have implications for new antimicrobial prophylactic strategies.

Post-transplant lymphoproliferative disorders

Post-transplant lymphoproliferative disorder is the most common malignancy, with the exception of skin cancer, after solid organ transplantation in adults. The incidence varies according to the transplanted organ and is often associated with Epstein-Barr virus. Prognosis is variable, due in part to the heterogeneity of the disease, which ranges from reactive plasmacytic hyperplasia to aggressive monoclonal disease.

B-cell posttransplant lymphoproliferative disorders in heart and/or lungs recipients: clinical and molecular-histogenetic study of 17 cases from a single institution

BACKGROUND

Posttransplantation lymphoproliferative disorders (PTLDs) are heterogeneous lymphoid proliferations representing a major complication of solid organ transplant. This study details the clinicopathological and molecular features of 17 B-cell PTLDs observed in a single center series of 988 heart and/or lung transplant recipients.

METHODS

Cases were classified according to World Health Organization lymphoma classification and tested for Epstein-Barr Virus (EBV), clonality, histogenetic phenotypic (CD10, Bcl-6, MUM1, CD138), and genotypic (immunoglobulin and BCL-6 genes somatic hypermutation) markers.

RESULTS

This series of 17 PTLDs included: two B-cell monoclonal polymorphic PTLDs and 15 B-cell monomorphic PTLDs (13 diffuse large B-cell lymphomas [DLBCL] and 2 Burkitt lymphomas [BL]). EBV was detected in 9/17 cases. A monoclonal immunoglobulin variable (IGV) genes rearrangement was documented in 17/17 cases; IGV somatic hypermutation was found in 88% of cases, indicating a prevalent origin from germinal center (GC)-experienced B cells. Using immunophenotypic markers, three histogenetic profiles were identified: a) CD10/bcl-6/MUM1/CD138, mimicking GC B-cells; b) CD10-/bcl-6+/MUM1+/CD138-, reminiscent of B-cells at the latest phases of GC reaction; and c) CD10-/bcl-6-/MUM1+/CD138+/-, consistent with preterminally differentiated B-cells.

CONCLUSIONS

Correlation between morphology, histogenesis, and EBV status demonstrated a high degree of homogeneity in the two GC-related groups, mostly including EBV-negative cases with BL and DLBCL-centroblastic features; the third group, consisting of post GC EBV-positive cases, was histologically less homogeneous, as it included polymorphic PTLDs and DLBCL with immunoblastic and anaplastic features. The EBV-negative cases with GC histogenetic phenotype showed a slightly better outcome; however, such less aggressive prognostic trend was not confirmed by statistical analysis.

Posttransplant lymphoproliferative disorder: A pictorial review

Posttransplant lymphoproliferative disorder (PTLD) is a serious and potentially fatal complication after solid organ and haemopoietic stem cell transplantation. The frequency of PTLD varies with the type of organ transplant but overall it affects 2-10% of all solid organ transplant recipients. Most cases develop within 1 year after the transplant, although occasional cases present 5-10 years later. Posttransplant lymphoproliferative disorder is clinically and pathologically heterogeneous - the majority are of the non-Hodgkin's lymphoma type, whereas Hodgkin's lymphoma arising after transplantation is rare. We have retrospectively reviewed patients with a histological diagnosis of PTLD after a solid organ transplant. We present the imaging features and a clinical review of this condition. Early diagnosis of PTLD may alter the management and outcome of the disease. The radiologist can play a vital role in establishing the diagnosis by imaging features supplemented with percutaneous biopsy and also in monitoring the disease response to treatment.

Temporary elevation of serum transaminases after pediatric intestinal transplantation: incidence and clinical correlation in multivisceral transplant vs isolated intestinal transplant

Data were gathered from the records of 51 children of median age 1.5 years who survived more than 6 months after intestinal transplantation. Abnormal liver function tests (LFTs) were defined as serum aspartate aminotransferase (AST) greater than 100 IU/L or total bilirubin greater than 2.0 g/dL lasting more than 3 days. Temporary elevation was defined when LFTs returned to normal without graft loss or death. LFT elevation at the time of transplantation was not included as a temporary LFT elevation. Median follow-up was 36 months. In multivisceral transplant recipients, all patients (n = 34) showed abnormal LFTs at transplantation that normalized within a median period of 2 days. Temporary LFT elevations were seen in 20 of 34 (59%) in multivisceral transplantation and 5 of 17 (29%) in isolated intestinal transplantation. Median length of elevation was 14 days in multivisceral transplantation and 12 days in isolated intestinal transplantation. Peak AST was 353 +/- 190 IU/dL in multivisceral transplantation and 839 +/- 605 IU/dL in isolated intestinal transplantation (P = .0059). Events associated with temporary LFT elevations in multivisceral transplantation were total parental nutrition (TPN) (n = 8), dehydration (n = 2), viral infection (n = 2), others (n = 3), and nonspecific (n = 5). Events in isolated intestinal transplantation were posttransplant lymphoproliferative disorder (n = 2), TPN (n = 1), and nonspecific (n = 2). Temporary LFT elevations were commonly seen among pediatric intestinal recipients, which correlated with events other than rejection. Approximately half of the temporary LFT elevations were associated with no significant clinical events. They resolved spontaneously. Interestingly, the peak AST value was higher in isolated intestinal transplantation compared to multivisceral transplantation.

Post-transplant de novo malignancies in renal transplant recipients: the past and present

Post-transplant de novo malignancies are reviewed in three time periods: (i) the azathioprine (AZA) era from 1962 to 1980-1981, (ii) the cyclosporine (CYA) era (1980 to present) in which the calcineurin inhibitors, CYA and tacrolimus (TAC), were the mainstay of recipient immunosuppression, and (iii) the TOR inhibitor era starting in the year 2000. Both transplant registry and transplant center reports on malignancies occurring in the AZA era are reviewed. Reports from transplant centers and from the Cincinnati Transplant Tumor Registry (CTTR) in both the early CYA era (1980s) and the 1900-2000 CYA era are reported. Cancer incidence associated with AZA versus CYA, CYA versus TAC, and AZA versus mycophenolate mofetil (MMF) is compared in both transplant center and registry reports including new, unreported Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) data from 1998 to 2003. The malignancy incidence associated with lymphocyte-depleting antibody and corticosteroid immunosuppression is discussed. Reduced malignancy incidence recently reported with TOR inhibitors is compared with that of conventional immunosuppression. Important nondrug factors influencing the incidence of post-transplant malignancies from seven single and three registry reports are detailed. The substantial role that de novo malignancies play in post-transplant mortality is discussed. Finally, management recommendations for recipients who develop de novo post-transplant malignancies are briefly presented.

Viral lymphomagenesis

PURPOSE OF REVIEW

Several viruses have been associated with lymphomageneisis. Epstein-Barr virus is associated with B-cell lymphomas in immunosuppressed patients as well as some cases of Burkitt's lymphoma, some T and natural killer lymphomas and approximately 40% of cases of Hodgkin's disease. Human T-cell leukemia virus 1 and human herpes virus 8 genomes are also found in tumor cells in some types of lymphoma, while there are epidemiological data linking hepatitis C and lymphoma. The presence of the viral genome in all these malignancies offers the prospect for therapeutic interventions targeting virus-encoded proteins.

RECENT FINDINGS

Immunotherapy with antigen-specific T cells has efficacy in immunosuppressed patients with Epstein-Barr virus-associated posttransplant lymphoma and in some patients with Epstein-Barr virus-positive Hodgkin's disease. Preclinical studies are focusing on agents that block Epstein-Barr virus-encoded proteins or induce lytic cycle agents. In hepatitis C virus-positive lymphomas, responses have been reported with immune modulation. Increasing knowledge of cellular pathways modulated by viruses provides additional potential targets for therapy.

SUMMARY

While the contribution to oncogenesis of Epstein-Barr virus in B-cell lymphoproliferative disease arising in immunosuppressed patients is clear cut, its role and that of other viruses in lymphomagenesis is less clear in lymphomas developing in immunocompetent patients. The presence of viral genomes in these lymphomas, however, offers targets for intervention and approaches under evaluation include adoptive immunotherapy, interferon, and small molecules targeting aspects of virus biology.

Successful in vitro priming of EBV-specific CD8+ T cells endowed with strong cytotoxic function from T cells of EBV-seronegative children

Epstein-Barr virus (EBV)-seronegative transplant recipients are at high risk of developing EBV-associated post-transplant lymphoproliferative disorder (PTLD), and would maximally benefit from an EBV-directed T-cell therapy for prevention or treatment of PTLD. So far, efforts to activate CD8+ EBV-specific cytotoxic T lymphocytes (CTL) endowed with high specific cytotoxicity from EBV-seronegative children have failed. We compared the CD8+ CTL priming efficiency of three different modified activation protocols, based on lymphoblastoid cell lines (LCL) stimulation potentially enhanced by either LCL presentation through dendritic cells, or selection of IFN-gamma+ cultured cells, or culture in the presence of rhIL-12 and rhIL-7, according to the standard protocol for reactivation of EBV-specific CTL. We found that only specific LCL stimulation in the presence of rhIL-12 and rhIL-7 was able to reproducibly expand EBV-specific CD8+ CTL endowed with strong cytotoxic activity from truly EBV-seronegative children. The lines thus activated, which included specificities toward EBV latent and lytic proteins, showed high percentage CD8+ T cells, with <10% naïve CD8+/CCR7+/CD45RA+ cells. Overall, the total number of CD8+ central memory cells, and of CCR7 T-cell effectors was comparable to that observed in healthy EBV-seropositive controls. In conclusion, it is feasible to activate EBV-specific CD8+ CTL with suitable characteristics for in vivo employment from EBV-seronegative children.

Circulating Epstein-Barr virus (EBV) in HIV-infected patients and its relation with primary brain lymphoma

OBJECTIVE

To analyze Epstein-Barr virus (EBV) load at different HIV infection stages and its relation with brain lymphoma.

DESIGN

A cross-sectional study was conducted on 172 HIV-infected individuals: 62 asymptomatic HIV carriers (group A), 30 HIV progressors (group B), 73 AIDS patients (group C), seven AIDS patients with brain lymphoma (group C-BL); and 26 blood donors (group BD) as healthy carriers. EBV load was measured in peripheral blood mononuclear cells (PBMC) and plasma samples using a semi-quantitative PCR method.

RESULTS

PBMC-EBV levels in HIV-infected patients were higher than in the blood donors (p<0.05). No differences in PBMC-EBV loads were found in groups A, B, or C (p>0.05), while the C-BL group had significantly lower levels (p<0.05). Similar PBMC-EBV loads were seen in HIV-infected patients with CD4+ T cell counts higher than 50/mm(3) (p>0.05), while significantly lower levels were found in cases with less than 50 cells/mm(3) (p<0.05). In all HIV-infected patients, plasma-EBV load was lower than, or similar to, PBMC-EBV load, unlike 2/7 HIV-positive brain lymphoma patients.

CONCLUSIONS

During HIV infection PBMC-EBV load rises in comparison to healthy carriers, but decreases when immunosuppression progresses and CD4+ T cell count becomes <50/mm(3). Circulating EBV is mainly cell-associated in the HIV-infected population. Neither PBMC-EBV nor plasma-EBV loads would be useful to diagnose brain lymphoma in AIDS patients.

Monitoring of EBV-DNAemia by quantitative real-time PCR after adult liver transplantation

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) causes significant morbidity and mortality in transplantation. The clinical significance of Epstein-Barr virus (EBV) in the development of PTLD is clear, but not all EBV-reactivations cause PTLD.

OBJECTIVES

We retrospectively analyzed EBV-DNAemia in liver transplant patients by a quantitative TaqMan-based real-time plasma PCR.

STUDY DESIGN

Altogether 1284 specimens, obtained from 105 patients for frequent monitoring of cytomegalovirus (CMV) and human herpesvirus-6 and -7 (HHV-6, HHV-7) during the post-transplant year, were retrospectively tested for EBV-DNA.

RESULTS

Altogether, 14/105 (13%) patients showed EBV-DNAemia, which usually occurred within 3 months after transplantation and subsided within a few weeks. EBV-DNAemia occurred concurrently with CMV in 10/14, with HHV-6 in 11/14, and with all three betaherpesviruses in 4/14 cases. The peak viral loads were relatively low (median 2100 EBV-DNA copies/ml, range 568-6600), except in one patient who first had low-level EBV-DNA (562-3022 copies/ml) in the early post-transplant period, but on day 175 after transplantation developed high-level DNAemia (9851-86,975copies/ml) which continued for 6 months and developed into PTLD at 6 months after transplantation.

CONCLUSION

Low-level EBV-DNAemia is common after liver transplantation, often occurring together with betaherpesviruses, but seldom leads to high viral loads or PTLD. However, monitoring of EBV-DNA levels in the patients can be useful.

TGF-beta inhibition of CTL re-stimulation requires accessory cells and induces peroxisome-proliferator-activated receptor-gamma (PPAR-gamma)

Effective cellular immunity to Epstein-Barr virus (EBV), necessary to prevent or cure many post-transplant lymphoproliferative disorders (PTLD), can be inhibited by transforming growth factor-beta (TGF-beta). In vitro, TGF-beta inhibits memory CTL re-stimulation from whole PBMC. We show that the effect of TGF-beta on CTL re-stimulation is not directly on the T cell, but requires an accessory cell (AC) population. Further, pre-treatment of AC with TGF-beta significantly reduces memory CTL re-stimulation and suppresses delayed type hypersensitivity (DTH) responses. Addition of exogenous interferon-gamma to the AC overcomes the effects of TGF-beta. TGF-beta pre-treatment also up-regulates expression of peroxisome-proliferator-activated receptor-gamma (PPAR-gamma) in CD14(+) AC. Importantly, pre-treatment of AC with the PPAR-gamma ligand, ciglitazone, results in significantly reduced memory CTL re-stimulation. Thus, the effects of TGF-beta in this system may be mediated in part via PPAR-gamma, and PPAR-gamma activation could have significant inhibitory effects on memory T-cell responses by affecting AC function. These data have important implications in understanding how memory CTL are re-stimulated and function to prevent disease, especially PTLD.

CMV-IVIG for prevention of Epstein Barr virus disease and posttransplant lymphoproliferative disease in pediatric liver transplant recipients

A randomized controlled trial of CMV-IVIG (cytomegalovirus-intravenous immunoglobulin) for prevention of Epstein Barr virus (EBV) posttransplant lymphoproliferative disease (PTLD) in pediatric liver transplantation (PLTx) recipients was begun in Pittsburgh and subsequently expanded to four additional sites. Protocol EB viral loads were obtained in a blinded fashion; additional loads could be obtained for clinical indications. Patients were followed for 2 years post-LTx. Eighty-two evaluable patients (39 CMV-IVIG, 43 placebo) developed 18 episodes of EBV disease (7 CMV-IVIG, 11 placebo) including nine cases of PTLD (three CMV-IVIG, six placebo). No significant differences were seen in the adjusted 2-year EBV disease-free rate (CMV-IVIG 79%, placebo 71%) and PTLD-free rate (CMV-IVIG 91%, placebo 84%) between treatment and placebo groups at 2 years (p > 0.20). The absence of significant effect of CMV-IVIG may be explained by a lack of efficacy of the drug or limitations of sample size.

Malignancy in pediatric transplant recipients

Malignancy is a well defined complication of chronic immunosuppression. Post transplant malignancies appear to be related to cumulative doses of immunosuppression, and in pediatric patients, acute infection of previously naive patients. The most commonly encountered malignancy in this age population is Post Transplant Lymphoproliferative Disorder (PTLD). PTLD is not a single entity but rather represents a continuum of disease. Treatment of PTLD should be initiated with immunosuppression reduction. Standard dose chemotherapy leads to significant morbidity. With the introduction of anti-CD20 antibody treatment with rituximab, chemotherapy has become second line therapy. The occurrence of solid malignancy appears to be associated with chronic immunosuppression. These cancers include those of skin, gynecologic organs, and the rectum, all of which appear to have the strongest association with viral mediators. Several strategies have been postulated to minimize the occurrence of malignancy. These include ganciclovir prophylaxis for the prevention of PTLD and the use of mychophenolic acid and TOR inhibitor maintenance to diminish the incidence of PTLD and solid malignancies. This leaves transplant physicians with several new and novel immunosuppressive agents with uncertain oncologic potentials that will need to be examined over the next decade.

Review of Epstein–Barr virus and post-transplant lymphoproliferative disorder post-solid organ transplantation (Review Article)

Post-transplant lymphoproliferative disorder (PTLD) following solid organ transplantation is an important form of post-transplant malignancy. PTLD is typically associated with Epstein-Barr virus (EBV) and occurs in the setting of profound immunosuppression resulting in a deficiency of EBV-specific cytotoxic T lymphocytes (CTL). Predisposing factors include EBV mismatch between donor and recipient, use of immunosuppression especially T-cell depletive therapies and genetic predisposition of recipients. The standard approach has been to reduce immunosuppression but is often insufficient to induce tumour regression. Further understanding of the immunobiology of PTLD has resulted in improved monitoring techniques (including EBV viral load determined by polymerase chain reaction) and newer treatment options. Recent work has highlighted a potential role for dendritic cells in both the pathogenesis and treatment of PTLD. Current treatment modalities include adoptive immunotherapy using ex vivo generated autologous EBV-specific CTL or allogeneic CTL, cytokine therapies, antiviral agents, and more recently, rituximab and dendritic-cell based therapies. This review focuses on the developments and progress in the pathogenesis, diagnosis and treatment of PTLD.

Use of an immune function assay to monitor immunosuppression for treatment of post-transplant lymphoproliferative disorder

The first-line treatment for PTLD is reduction in immunosuppression, allowing partial reconstitution of cell-mediated immunity. However, there is a risk of inducing acute allograft rejection during clinical resolution of PTLD. A recently available assay, Immuknow, measures the cell-mediated immune response and could be used to monitor reduction of immunosuppression. We report a case of PTLD occurring in a pediatric kidney transplant recipient where the reduction in immunosuppression was serially followed using this assay and quantitative EBV-PCR. A rapid reduction to minimal immunosuppression was followed by resolution of PTLD. Later, when the cell-mediated immune response increased, with negative viral load, immunosuppression was gradually increased utilizing the assay to adjust dosing. Presently, there are no signs of PTLD and renal function remains normal.

Infectious complications in renal transplant recipients

Post-kidney transplant infection is the most common life-threatening complication of long-term immunosuppressive therapy. Optimal immunosuppression, in which a balance is maintained between prevention of rejection and avoidance of infection, is the most challenging aspect of posttransplantation care. The study of infectious complications in immunologically compromised recipients is changing rapidly, particularly in the fields of prophylactic and preemptive strategies, molecular diagnostic methods, and antimicrobial agents. In addition, emerging pathogens such as BK polyomavirus and West Nile flavivirus infections and the introduction of newer immunosuppressive agents that constantly change the risk profiles for opportunistic infections has added layers of complexity to this burgeoning field. Although remarkable progress has been made in these disciplines, comprehensive understanding of the clinical manifestations of infections remains limited, and the standardization of prophylaxis, diagnosis, and treatment of most infections is yet inadequately defined. The long-term goal for optimal care of transplant recipients, with respect to infection, is the prevention and/or early recognition and treatment of infections while avoiding drug-related toxicities.

EBV B lymphoma cell lines from patients with post-transplant lymphoproliferative disease are resistant to TRAIL-induced apoptosis

Lymphomas associated with post-transplant lymphoproliferative disease (PTLD) represent a significant complication of immunosuppression in transplant recipients. In immunocompetent individuals, EBV-specific cytotoxic T lymphocytes (CTL) prevent the outgrowth of activated B lymphoblasts through apoptosis induction. Soluble versions of TNF-related apoptosis-inducing ligand/Apo2 ligand (TRAIL) can induce apoptosis in numerous tumor cell types. Given the therapeutic potential of TRAIL, we examined the sensitivity of EBV+ spontaneous lymphoblastoid cell lines (SLCL) derived from patients with PTLD to treatment with soluble TRAIL. Despite abundant expression of TRAIL receptors (TRAIL-R), resistance to TRAIL-induced apoptosis was observed in all SLCL examined. This resistance could not be overcome by concomitant treatment with several pharmacological agents. Unlike BJAB positive control cells, for each SLCL tested, cleavage and activation of caspase 8 was inhibited due to failed recruitment of FADD and caspase 8 to TRAIL receptors upon stimulation. Further indicative of a proximal defect, TRAIL receptor aggregation could not be detected on the cell surface of SLCL following ligand engagement. These results suggest that the use of TRAIL for eliminating PTLD-associated tumors may be of limited clinical utility, and illustrate another mechanism by which EBV+ B lymphoma cells can evade tumor surveillance at the level of death receptor signaling.

Post-transplant lymphoproliferative disorders following liver transplantation: incidence, risk factors and survival

This study investigates retrospectively the incidence, risk factors and mortality of post-transplant lymphoproliferative disorders (PTLD) in adult orthotopic liver transplant (OLT) recipients. Among 1206 OLT recipients at a single institution, 37 developed a PTLD. The incidence of PTLD was highest during the first 18 months and relatively constant thereafter with cumulative incidence of 1.1% at 18 months and 4.7% at 15 years. The risk of PTLD was approximately 10% to 15% of the risk of death without PTLD. During the first 4 years following OLT, PTLD were predominantly related to EBV, while afterward most PTLD were EBV negative. Significant risk factors for PTLD in OLT recipients were transplantation for acute fulminant hepatitis during the first 18 months following OLT (HR=2.6, p=0.007), and rejection therapy with high-dose steroids (HR=4.5, p=0.049) and OKT3 (HR=3.9, p=0.016) during the previous year. Therapy with high-dose steroids or OKT3 (HR=3.6, p=0.0071) were also significant risk factors for PTLD-associated mortality. OLT recipients remain at risk for PTLD years after transplantation. The strong association of PTLD with rejection therapy and the worse post-PTLD prognosis among recipients of rejection therapy indicate the need to balance the risk of immunosuppression against the risk of PTLD following rejection treatment.

A randomized trial of ganciclovir versus ganciclovir plus immune globulin for prophylaxis against Epstein-Barr virus related posttransplant lymphoproliferative disorder

BACKGROUND

Transplant recipients who are Epstein-Barr virus (EBV)-seronegative and receive organs from seropositive donors (EBV D+/R-) are at increased risk for posttransplant lymphoproliferative disorder (PTLD) and may benefit from antiviral prophylaxis. We performed a multi-center trial assessing two different antiviral regimens and their effect on EBV replication.

METHODS

EBV D+/R- solid organ transplant recipients were randomized to receive either ganciclovir and placebo or ganciclovir and immunoglobulin (IG) for 3 months. Following this, patients were unblinded and IG patients received additional IG therapy until 6 months. EBV viral loads were done at least monthly. RESULTS.: Thirty-four patients (25 pediatric, 9 adult) completed the protocol (16 placebo; 18 IG). The incidence of a detectable viral load within the first year posttransplant was 13/16 (81.3%) in the ganciclovir arm vs. 13/18 (72.2%) in the ganciclovir and IG arm (P=0.8). Time to first detectable viral load, and time to high-level viral load were not significantly different. By repeated measures ANOVA analysis, and by estimation of viral load AUC, no significant effect of randomization group was observed on EBV viral loads. PTLD developed in 3 (8.8%) patients (all in IG arm; P=0.23).

CONCLUSIONS

No significant difference in EBV viral load suppression was observed when ganciclovir was compared with ganciclovir and IG in high-risk EBV D+/R- patients.

Epstein-Barr virus-associated lymphomas

Following Epstein and colleagues' ground-breaking discovery of Epstein-Barr virus by electron microscopy of Burkitt's lymphoma cell lines, there came the observation that Epstein-Barr virus induces immortalization of B cells in vitro. Thus, initial hopes were of a virus confined to equatorial Africa with a causal link to a particular subtype of childhood lymphoma. Over the past 40 years there has been great progress towards understanding the biology and epidemiology of Epstein-Barr virus, which conclusively show that these early ideas were overly simplistic. It is now known that Epstein-Barr virus has a seroprevalence of approximately 95% worldwide, and persists for life within host B lymphocytes. Infection in New World primates leads to lymphoma and inoculation of peripheral blood mononuclear cells from Epstein-Barr virus-seropositive subjects into severe combined immunodeficiency mice results in B-cell lymphoproliferative disorders. Epstein-Barr virus is now known to be implicated in a range of lymphoid and other malignancies, and this association will be the subject of this review.

Treatment of PTLD with rituximab or chemotherapy

Information regarding treatment of post-transplant lymphoproliferative disease (PTLD) beyond reduction in immunosuppression (RI) is limited. We retrospectively evaluated patients receiving rituximab and/or chemotherapy for PTLD for response, time to treatment failure (TTF) and overall survival (OS). Thirty-five patients met inclusion criteria. Twenty-two underwent rituximab treatment, with overall response rate (ORR) 68%. Median TTF was not reached at 19 months and estimated OS was 31 months. In univariable analysis, Epstein-Barr virus (EBV) positivity predicted response and TTF. LDH elevation predicted shorter OS. No patient died of rituximab toxicity and all patients who progressed underwent further treatment with chemotherapy. Twenty-three patients received chemotherapy. ORR was 74%, median TTF was 10.5 months and estimated OS was 42 months. Prognostic factors for response included stage, LDH and allograft involvement by tumor. These factors and lack of complete response (CR) predicted poor survival. Twenty-six percent of the patients receiving chemotherapy died of toxicity. Rituximab and chemotherapy are effective in patients with PTLD who fail or do not tolerate RI. While rituximab is well tolerated, toxicity of chemotherapy is marked. PTLD patients requiring therapy beyond RI should be considered for rituximab, especially with EBV-positive disease. Chemotherapy should be reserved for patients who fail rituximab, have EBV-negative tumors or need a rapid response.

Post-transplant lymphoproliferative disorders after lung transplantation: first-line treatment with rituximab may induce complete remission

BACKGROUND

Post-transplant lymphoproliferative disorders (PTLD) are potentially lethal complications of solid organ transplantation. We, here, report on our experience with rituximab, an anti-CD20 monoclonal antibody, as first-line treatment for PTLD in six lung transplant recipients.

PATIENTS AND METHODS

Two of the patients developed PTLD during the first year after transplantation, while four developed late-onset PTLD. One patient presented with PTLD localized to the graft, one had unilateral cervical lymph nodes, and the others presented with multi-organ involvement. All patients had diffuse large B-cell lymphoma. Immunosuppressive therapy was reduced and rituximab was administered at a dose of 375 mg/m(2)/wk for 4 wk.

RESULTS

One patient did not respond to the first two courses of rituximab, received conventional chemotherapy, and achieved complete remission; four patients achieved complete remission after four courses with a median relapse-free survival of 34 months (range: 14-55); and one patient did not respond and died. The diagnosis of complete remission was established by conventional imaging techniques combined to whole-body positron emission tomography scan.

CONCLUSIONS

We conclude that reduction in immunosuppression combined to first-line treatment with rituximab may induce long-term complete remission in lung transplant recipients presenting PTLD.

American Society of Transplantation recommendations for screening, monitoring and reporting of infectious complications in immunosuppression trials in recipients of organ transplantation

In recent years, major progress has been made in the development, investigation and clinical application of novel immunosuppressive drug therapies to prevent acute rejection. Critical to the ultimate clinical application of new drug therapies is the ongoing performance of large multi-center clinical trials. However, there has been a paucity of infectious disease monitoring built into these protocols. Given that infectious complications are a major source of morbidity and mortality in transplant recipients, the assessment of the magnitude of risk of infection associated with a given immunosuppressive strategy may be as important as the assessment of rejection. For the above reasons, screening, monitoring and reporting recommendations for common transplant-associated infections were developed for use in clinical trials evaluating immunosuppressive strategies. These recommendations have two major goals: (i) to provide clinically relevant definitions for tracking infectious complications occurring in participants in immunosuppressive trials and (ii) where appropriate, to recommend specific laboratory monitoring and surveillance methods.

Rituximab as treatment of posttransplant lymphoproliferative disorder in patients who underwent small bowel/multivisceral transplantation: report of three cases

This report describes three cases of posttransplant lymphoproliferative disorder (PTLD) in multivisceral/small bowel transplant patients treated with rituximab (anti-CD20 monoclonal antibodies). In two cases (one of which was a B-cell lymphoma) a good response to therapy was achieved. A third case (with polymorphic PTLD with low CD20 expression) developed a refractory rejection and PTLD was still documented on graftectomy. Rituximab was well tolerated, and a reduction of Epstein-Barr virus (EBV) viral load was documented by quantitive competitive-EBV polymerase chain reaction. Efficacy of therapy needs to be assessed in controlled studies.

Rituximab therapy is effective for posttransplant lymphoproliferative disorders after solid organ transplantation: results of a phase II trial

BACKGROUND

Posttransplant lymphoproliferative disorders (PTLD) remain an uncommon complication of solid organ transplantation with a high mortality rate reported after conventional therapies. Alternative treatments such as rituximab have been explored.

METHODS

Eleven patients with PTLD, who were CD20 positive, received an intravenous dose of rituximab, 375 mg/m2, weekly x 4 weeks, repeated every 6 months for 2 years in responding patients. The median age of the patients was 56 years (range, 43-68 yrs), and 9 patients were male. The type of solid organ transplantation that these patients received included lung (five patients), kidney (four patients), heart (one patient), and kidney/pancreas (one patient). The median time from transplantation to a PTLD diagnosis was 9 months (range, 1-122 mos). Diagnostic B-cell histology was diffuse large cell lymphoma or polymorphous process. No patient had bone marrow or central nervous system involvement. Primary extranodal disease was noted in 82% of patients. Immunosuppressive therapy was decreased at the time of diagnosis.

RESULTS

Rituximab was well tolerated, with mild infusional blood pressure alterations noted in two patients. The median follow-up period was 10 months (range, 1-32 mos). The overall response rate was 64%, with 6 complete responses (CR), 1 partial response, 2 cases of progressive disease, and 2 deaths. The median duration of CR was 8 months (range, 2-19+ mos). The median time to treatment failure was 10 months (range, 5-25+ mos). The median survival was 14 months (range, < 1-32+ mos). Four patients were alive at the time of last follow-up.

CONCLUSIONS

Single-agent rituximab may offer a response and survival advantage in patients with PTLD. Further evaluation of rituximab in these disorders, potentially in combination with other therapies, is warranted.

Viral and fungal infections after liver transplantation--part II

Viral and fungal infections in liver transplant recipients are important to recognize and treat early because of their association with substantial morbidity and mortality. Some viruses, such as cytomegalovirus and human herpesvirus 6, have immunomodulatory properties and can facilitate other infections, including fungal infections. Cytomegalovirus has long been recognized as an important virus in transplantation, but in the past decade other viruses have also received attention in the medical literature because of their association with particular clinical syndromes. Although human herpesvirus 6 has been associated with fever, rash, and encephalitis, a direct cause-and-effect relationship is still lacking. Human herpesvirus 8 has been found to be the cause of Kaposi sarcoma. Molecular techniques (e.g., pp65 antigenemia and polymerase chain reaction) that have been introduced for routine diagnosis of viruses have facilitated the diagnosis of asymptomatic viral infections and the institution of preemptive therapy. Nonetheless, the diagnosis of invasive fungal infections in liver transplant recipients is often delayed and thus associated with high mortality. Despite the use of new antifungal agents in clinical practice and the reduced incidence of fungal infections because of antifungal prophylaxis regimens, mortality has not decreased. Future patient outcomes may improve with early identification of patients who have risk factors for invasive fungal infections and with the development of new molecular diagnostic techniques for early detection.

Outcome, Incidence, and Timing of Infectious Complications in Small Bowel and Multivisceral Organ Transplantation Patients

BACKGROUND

Infectious complications still represent a major cause of morbidity and mortality in patients with organ transplantation. In particular, small bowel or multivisceral transplantation is complicated to a greater extent than other grafts as a consequence of infectious complications including sepsis.

METHODS

This prospective study assessed outcome, incidence, and timing of infections in sequential patients undergoing small bowel or multivisceral transplantation (SB/MVTx) performed at a university transplant center between January 2001 and October 2003. Nineteen patients underwent transplantation during this period, 13 of whom (68%) undergoing isolated SB and 6 (32%) MV grafts with or without liver.

RESULTS

The median follow up was 524 days (interquartile range=252-730) with an overall 24.4 person/year of observation. Postoperative mortality rate was 0.1 death/person/year; all patients, except one who died intraoperatively, were alive 6 months postsurgery. There were 100 documented infections including: 59 bacterial (2.4 events/person/year), 35 viral (1.4 events/person/year) and 6 fungal (0.2 events/person/year). Patients developed at least one episode of bacterial infection in 94% of the cases, viral infection in 67%, and fungal infection in 28%.

CONCLUSIONS

This cohort describes the very common and complex nature of infectious complications in this challenging group of transplantation patients. Larger cohorts are needed to specifically address infection risk factors and longer term outcomes.

Post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder (PTLD) is an increasingly recognized complication of solid organ and hematopoietic stem cell transplantation. PTLD represents a spectrum of polyclonal and monoclonal lymphoproliferation, generally of B cells. Prompt diagnosis is key and requires a high index of suspicion. An increasing variety of highly effective therapies, including immune modulation via reduction in immunosuppression, monoclonal antibodies, and cellular therapy, have dramatically improved the cure rates of this once devastating disease.

Incidence and risk factors for cancer after liver transplantation

De novo tumors (DNT) are a serious complication after orthotopic liver transplantation (OLT), showing a higher overall incidence ranging from 4.7% to 15.7% in non-selected series. Skin cancer (SC) is the most frequent malignancy observed, ranging from 6% to 70% of the tumors observed, followed by post-transplant lymphoproliferative disorders (PTLD) (4.3-30%). Different immunosuppressive protocols do not seem to influence DNT appearance. Colon and upper aerodigestive cancer after OLT seems to be more prone to develop when there are associated risk factors, such as primary sclerosing cholangitis (PSC) and alcoholic liver cirrhosis (ALC). Some risk factors, such as age, smoking, alcohol and others seem to play a role in higher risk for malignancy, but the presence of a long-term immunosuppressive state, more than the specific regimen used, is the basis for this higher incidence. Ethnic and demographic factors are also important variables influencing the heterogeneity of the results, especially influencing Kaposi's sarcoma and skin tumors.

Post-transplant lymphoproliferative disorders (PTLD) after solid organ transplantation

Post-transplant lymphoproliferative disorders (PTLD) are a well-recognised and potentially fatal complication after solid organ transplantation. They include a spectrum of disorders ranging from benign hyperplasia to invasive malignant lymphoma. The majority of cases are associated with Epstein Barr virus (EBV)-driven tumour formation in B cells and are a consequence of the detrimental effect of immunosuppressive agents on the immune-control of EBV. This review provides an update on the pathogenesis and clinical features of PTLD after solid organ transplantation and discusses recent progress in management. Reduction in immunosuppressive therapy remains a key component of therapy for EBV-positive PTLD and may lead to remission in early disease. Chemotherapy is used when reduced immunosuppression fails to control early disease and as initial therapy for many cases of late disease. Unfortunately, the mortality for PTLD that fails to respond to a reduction in immunosuppression remains high. Newer treatments include manipulation of the cytokine environment, B lymphocyte depleting antibodies and adoptive T cell immunotherapy using allogeneic or autologous EBV-specific cytotoxic T lymphocytes. Although early results appear promising, well-designed clinical trials are needed to assess the efficacy of these novel approaches. EBV vaccination may in the future prove an effective prophylaxis against EBV-driven PTLD but until then, avoiding excessive immunosuppressive therapy may help minimise the risk of PTLD.

Viruses and lymphoma

The aetiology of lymphomas is poorly understood and the striking increase in its incidence rate in developed societies remains unexplained. The concept of lymphoma as a virally-induced malignancy is not surprising since viruses are implicated in approximately 15% of all cancers. However, lymphoma represents a complex multistep process and, although viral associations have been identified, integration of the available epidemiological and scientific data poses substantial questions. The study of oncogenic viruses has and will continue to yield major insights into the pathogenesis of lymphoma. Further research is likely to uncover new lymphoma associations between both known and as yet unidentified viruses, may provide cellular and pharmacological targeted antiviral therapy strategies for the treatment of malignant lymphoma, and ultimately may generate the most promising avenue for lymphoma prevention.

Rituximab treatment for posttransplant lymphoproliferative disorder (PTLD) induces complete remission of recurrent nephrotic syndrome

A 12-year-old Japanese boy who underwent kidney transplantation with a kidney from his mother developed severe proteinuria immediately after the operation. Because his original disease was nephrotic syndrome (focal segmental glomerulosclerosis, or FSGS) and electron microscopic examination of the renal biopsy showed foot process fusion, we diagnosed this as a recurrence of nephrotic syndrome to the transplanted kidney. Four months after the transplantation, posttransplant lymphoproliferative disorder (PTLD) developed, which was pathologically diagnosed as diffuse large B cell lymphoma. Treatment consisting of a reduction in immunosuppression resulted in improvement in PTLD a month after the start of treatment. However, relapse occurred 2 months after the first onset of PTLD, which we treated with rituximab (CD-20 monoclonal antibody 375 mg/m2) once weekly for a total of four doses. The PTLD resolved immediately after the rituximab treatment was started, and, interestingly, urinary protein levels also improved at the same time. Three years later, the boy shows no signs of PTLD, and no proteinuria has been detected. These findings suggest that rituximab may be an effective treatment for recurrence of nephrotic syndrome after transplantation and that activated B cells may play a pivotal role in the recurrence of nephrosis after renal transplantation.

Lymphoproliferative Disease After Lung and Heart-Lung Transplantation: First Description in Spain

Lymphoproliferative syndromes are the most common tumors in transplant recipients. More than 90% of posttransplantation lymphoproliferative syndromes (PTLS) are considered to be associated with Epstein-Barr virus, and 86% are of the B-cell line. Histopathology ranges from polymorphic-reactive to monomorphic forms. Clonality should be studied using molecular biology techniques. Clinically, a differentiation is usually made between early PTLS (occurring within 1 year after transplantation) and late PTLS, which occur as localized or disseminated nodal lymphomas. In localized forms, immunosuppression should be discontinued or decreased, and the involved area should be subsequently resected or irradiated. In disseminated cases, immunosuppression should be decreased and administration of acyclovir/ganciclovir should be considered. If this is not effective, treatment should be started with anti-CD20 monoclonal antibodies (rituximab). If no response occurs, use of chemotherapy, possibly with interferon, should be considered. Our aim was to report the incidence, clinical signs, and treatment in a series of patients undergoing lung transplantation (LTx).

Posttransplantation Lymphoproliferative Disorder in Pediatric Recipients of Solid Organ Transplants: Timing and Location of Disease

OBJECTIVE

The objective of our study was to correlate the location of radiologic presentation and time to onset of posttransplantation lymphoproliferative disorder (PTLD) with the allograft type received in a population of pediatric heart, lung, liver, kidney, and bone marrow transplant recipients.

CONCLUSION

Symptomatic PTLD in children manifests earliest in lung recipients and can involve any organ system. However, PTLD in the thorax is most common after lung transplantation, and PTLD in the abdomen most commonly follows kidney transplantation.

Cancer incidence after immunosuppressive treatment following kidney transplantation

Cancer incidence is increased in renal transplant recipients due to immunosuppressant treatment that should be maintained to prevent and treat acute rejection. Use of new and very potent immunosuppressants has made it possible to reduce acute rejection incidence and improve renal graft survival, although increase of infections and post-transplant neoplasms have become clearer. On the other hand, renal transplant candidates who remain on dialysis have a greater prevalence of neoplasms than the age-matched general population, either because the neoplasm was the cause of their renal failure (multiple myeloma or kidney or urinary tract cancers) or because their renal disease entails a risk for cancer development (acquired cystic disease or analgesic nephropathy). Practically, all de novo neoplasms have a greater incidence in renal transplant patients. Cutaneous neoplasms are the most prevalent in renal transplant recipients and their incidence increases with transplant time. Post-transplant lymphoproliferative diseases are more frequent in patients who receive greater immunosuppression (antithymocyte/antilymphocyte globulin or OKT3) or are infected de novo by Epstein Barr Virus (EBV) through the transplanted kidney. Kaposi's sarcoma has a high incidence in the renal transplanted population, does not appear in the general population, and is related with Human Herpes Virus 8 (HHV-8) infections. The incidence of tumors in non-functioning native kidneys is especially high in renal transplant due to the presence of acquired cystic disease or analgesic nephropathy. Gold standards of post-transplant de novo renal neoplasm prevention are modulating immunosuppression and avoiding exposure to sunlight and to different oncogenic viruses (EBV, cytomegalovirus, hepatitis B and C viruses).

Prognostic analysis for survival in adult solid organ transplant recipients with post-transplantation lymphoproliferative disorders

PURPOSE

The objective of this study was to determine prognostic factors for overall survival in patients with post-transplantation lymphoproliferative disorders (PTLDs).

PATIENTS AND METHODS

This study focused on the 107 adult solid organ transplantation patients who were diagnosed with PTLDs at Mayo Clinic (Rochester, MN) between December 1970 and May 2003.

RESULTS

The median age at the time of diagnosis was 48 years (range, 15 to 75 years). Extranodal disease including grafted organ involvement was present in 85 patients (80%). The graft organ was involved in 30 patients (28%). At the time of these analyses, 62 patients (58%) had died. The median survival for the entire cohort was 31.5 months (95% CI, 10.7 to 72.5 months). The median follow-up of living patients was 51.8 months (range, 5.6 to 202.6 months). In univariate analyses for overall survival from the time of PTLD diagnosis, the following poor prognostic factors were identified: poor performance status with Eastern Cooperative Oncology Group levels 3 and 4 (P < .0001), grafted organ involvement (P = .0005), the presence of one or more extranodal sites (P = .005), both nodal and extranodal disease (P = .002), high International Prognostic Index (P = .006), advanced stage (P = .001), and elevated lactate dehydrogenase (P = .03). A final multivariable model for survival was constructed using three factors: poor performance status (3 to 4), monomorphic disease, and graft organ involvement.

CONCLUSION

A prognostic model has been developed for PTLD patients using one center's 30 years of experience. We propose additional confirmation and validation of these prognostic factors in larger prospective studies.

Low-Dose Chemotherapy for Epstein-Barr Virus–Positive Post-Transplantation Lymphoproliferative Disease in Children After Solid Organ Transplantation

Purpose

To evaluate the efficacy of a low-dose chemotherapy regimen in children with Epstein-Barr virus (EBV) –positive, post-transplantation lymphoproliferative disease (PTLD) after organ transplantation who have experienced failure with front-line therapy for PTLD.

Patients and Methods

Eligible patients received cyclophosphamide (600 mg/m2 intravenous for 1 day) and prednisone (2 mg/kg orally for 5 days) every 3 weeks for six cycles.

Results

Thirty-six patients treated on study were assessable for analyses. Front-line therapies for PTLD before study entry included immune suppression reduction or withdrawal (n = 36), antiviral therapy (n = 33), surgical resection (n = 8), rituximab (n = 2), and interferon alfa (n = 1). Reasons for failure of front-line therapy included progressive disease (PD; n = 33) and persistent disease with concurrent allograft rejection (n = 3). Thirty patients (83%) had stage III to IV disease, 92% had extranodal disease, and 75% had ≥ three sites of disease. The overall response rate was 83% (75% complete response + 8% partial response). The relapse rate was 19%, with only one of five relapsed patients alive and disease-free. Four patients presented with fulminant, disseminated PTLD; only one of these four patients achieved a response, and all four died of PD. Two patients died of treatment-related toxicity. Three patients (8%) experienced allograft loss, but two of the three patients are alive and disease-free after a second transplantation. The 2-year overall, relapse-free, and failure-free (without PTLD and with functioning original allograft) survival rates were 73%, 69%, and 67%, respectively.

Conclusion

This low-dose chemotherapy regimen is effective for children with EBV-positive, nonfulminant PTLD who have experienced treatment failure with front-line therapy, and this study represents the largest series of PTLD patients treated prospectively with a uniform chemotherapy regimen.

Early onset post-transplant lymphoproliferative disease is associated with allograft localization

Post-transplant lymphoproliferative disease (PTLD) is a major complication after solid organ transplantation. We analyzed incidence, patient characteristics, clinical presentation, and prognostic factors for treatment outcome and survival of PTLD patients transplanted at our center. Records from adult kidney and lung transplant recipients, transplanted between January 1985 and December 2002 with a histologically confirmed diagnosis of PTLD, were retrieved. Histology was reviewed and prognostic factors for treatment outcome were evaluated by multivariable analysis. Of 1354 kidney and 206 lung transplants, PTLD was diagnosed in 40 transplant recipients (2.6%). Lung transplant recipients had a significantly higher incidence of PTLD (8.3%) than kidney transplant recipients (1.7%). Sites of presentation were highly heterogeneous. Notably, PTLD localized in the allograft occurred significantly earlier after transplantation than PTLD localized outside the allograft (p = 0.001). This was true for lung (p = 0.006) as well as for kidney transplant recipients (p = 0.03). In multivariable Cox regression, performance status (p = 0.01) and advanced stage (p = 0.04) were factors negatively predictive for response to first-line treatment. Only performance status remained as negative predictive factor for survival (p = 0.002) and freedom from tumor progression (p = 0.01). In conclusion, the allograft is significantly more often involved as primary site of PTLD presentation during the first post-transplant year. This may have clinical consequences and give new insights in pathogenesis of PTLD. Performance status and stage are important risk factors for outcome of PTLD.