Interleukin-10 and posttransplant lymphoproliferative disorder after kidney transplantation

BACKGROUND: Posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication of transplantation, which comprises a morphologically and clinically heterogeneous spectrum of B-lymphocyte diseases. Risk factors include primary or reactivated Epstein-Barr virus (EBV) infection, and the type and duration of immunosuppression. Interleukin-10 (IL-10) is a pleiotropic cytokine, produced primarily by T-helper 2 (Th2) lymphocytes in the later stages of T-cell activation, suggested to play a role in EBV-associated PTLD. We recently reported preliminary findings on IL-10 in relation to the development of PTLD in three kidney transplanted patients. The study now includes nine patients that could be followed before and/or after the occurrence of lymphoma. METHODS: Nine patients with lymphomas (eight PTLDs and one Hodgkin's disease) were diagnosed among 268 consecutive renal transplantations (1990-1997). All were treated with cyclosporine with an initial 10-day course of antilymphocyte globulin, supplemented from 1995 with mycophenolate mofetil. Serum antibodies against EBV were detected using recombinant antigens. A double sandwich enzyme-linked immunosorbent assay using rabbit antibodies to purified human recombinant IL-10 was employed; the assay is specific for human natural and viral IL-10. RESULTS: Three patients experienced primary EBV infection, five reactivated EBV infections, and one did not change EBV status. Three patients had a fulminant course and died with EBV-associated PTLD confirmed post mortem. The other six are alive and are apparently cured. Treatment was immediate discontinuation of immunosuppression (in all PTLDs) and long-term high-dose aciclovir in all but one. Two patients have maintained excellent graft function for 3 and 2 years, respectively, without immunosuppression and are now in a state of operational tolerance. In three of four cases with initial lymphoma, EBV infection (primary or reactivation) preceded the increase in IL-10. In all four cases, the IL-10 increase preceded the PTLD diagnosis. In six cases, IL-10 could be followed after treatment showing either immediate zero or a decrease to zero. CONCLUSION: IL-10 seems to play a role in EBV-associated PTLD. Moreover, IL-10 may have an important role in transplant tolerance by inducing long-lasting anergy to donor- and host-specific alloantigens, perhaps caused by down-regulation of Th1 cytokines in the graft. If substantiated, this may provide new insight into the pathogenesis of PTLD introducing new strategies for prevention and therapy of PTLD, and for the induction of tolerance in transplanted patients.     

Metachronous EBV-associated B-cell and T-cell posttransplant lymphoproliferative disorders in a heart transplant recipient

Posttransplant lymphoproliferative disorders (PTLDs) may occur as a complication of immunosuppression in patients who have received solid organ or bone marrow allografts. Most PTLDs are of B-cell lineage, whereas T-cell proliferations are rare. The majority of B-cell lesions are associated with Epstein-Barr virus infection. The occurrence of both B-cell and T-cell PTLDs in the same patient is extremely rare and only 6 cases have been previously published. We report a case of a 63-year-old man who developed 2 metachronous Epstein-Barr virus-related PTLDs beginning 10 years after heart transplantation. A polymorphic B-cell PTLD developed first that completely regressed after immunosuppressive therapy was partially withdrawn. Then, a monomorphic T-cell PTLD developed 31 months later. The patient died 17 months later owing to disease progression. We highlight the diagnostic challenge of this case that required numerous ancillary studies for lineage assessment and classification. Such studies are often needed in patients with a history of immunosuppression.     

Outcomes of kidney retransplantation in recipients with prior post‐transplant lymphoproliferative disorder

Post‐transplant lymphoproliferative disease (PTLD) is an uncommon but serious complication of solid organ transplantation. Reduction in immunosuppression is the mainstay of PTLD treatment, but it may precipitate graft loss. Retransplantation remains controversial, as immunosuppression resumption may trigger PTLD relapse. Herein, we describe the experience of eight patients who underwent kidney retransplantation after successful PTLD treatment. Epstein–Barr virus (EBV) serology was not known before the first transplantation. PTLD was diagnosed 62.5 months (range 5–323 months) after transplantation and was confined to the renal allograft (n = 1), lymph nodes (n = 2), gastrointestinal tract (n = 4), or central nervous system (n = 1). Immunosuppression tapering (8/8), chemotherapy (6/8), oral cavity lymphoma excision (1/8), and allograft nephrectomy (1/8) led to hematological remission in all patients. Retransplantation was performed at a median of 55.5 months (range 29–95   months) after PTLD diagnosis. After a median follow‐up of 62.5 months (range 2–125 months) allograft survival was 87.5% (seven functioning grafts, one failed graft from chronic rejection), with no recurrence of PTLD. In all, five patients remain alive; the other three died from causes other than PTLD. In conclusion, kidney retransplantation appears to be safe in patients with prior PTLD and without major risk of hematological recurrence provided that PTLD has remitted.     

Post‐transplant lymphoproliferative disorder following kidney transplantation: a population‐based cohort study

Post‐transplant lymphoproliferative disorder (PTLD) incidence is difficult to determine, mainly because both early and other lesions may go unrecognized and unregistered. Few studies have included systematic pathology review to maximize case identification and decide more accurately PTLD frequency after long‐term post‐transplantation follow‐up. A retrospective population‐based cohort study including all kidney transplant recipients at two Danish centres (1990–2011; population covered 3.1 million; 2175 transplantations in 1906 patients). Pathology reports were reviewed for all patient biopsies to identify possible PTLDs. Candidate PTLDs underwent histopathological review and classification. Seventy PTLD cases were identified in 2175 transplantations (3.2%). The incidence rate (IR) after first transplantation was 5.4 cases per 1000 patient‐years (95% CI: 4.0–7.3). Most PTLDs were monomorphic (58.5%), or early lesions (21.5%). Excluding early lesions and patients <18 years, IR was 3.7 (95% CI: 2.9–5.5). Ten patients with PTLD were retransplanted, 2 developing further PTLDs. Post‐transplant patient survival was inferior in patients with PTLD, while death‐censored graft survival was not. Using registry data together with extensive pathological review and long follow‐up, a rather high incidence of PTLD was found.     

Indications and results of chemotherapy in children with posttransplant lymphoproliferative disease after liver transplantation

Among 39 posttransplant lymphoproliferative diseases (PTLD) in a cohort of 450 pediatric liver transplant recipients, 3 had a malignant lymphoma, unresponsive to arrest of immunosuppression and to gancyclovir, interferon, and anti-interleukin 6 antibodies. Lymphoma appeared 20, 46, and 96 months posttransplantation and 16, 43, and 90 months after primary Epstein-Barr virus infection. In one case, the patient had histological progression from plasmacytic hyperplasia PTLD, concomitant with symptomatic primary infection, to Burkitt-like lymphoma 43 months later. These three patients received five courses of chemotherapy, after a cyclophosphamide, doxorubicin, vincristine, and prednisone regimen for Burkitt-like or LH 89 scheme for Hodgkin-like PTLDs. Chemotherapy was well tolerated, and all three were free of disease and without immunosuppression 19, 14, and 4 months after chemotherapy. In Burkitt-like or Hodgkin-like PTLDs, immunomodulatory or antiviral drugs were inefficient. Chemotherapy is indicated and can be safely and successfully used. Long-term arrest of immunosuppression seems feasible without graft rejection.     

Early posttransplant lymphoproliferative disease in pediatric liver transplant recipients

Among 23 pediatric patients who underwent orthotopic liver transplant (OLT), we report two (11 and 26 months old) with posttransplant lymphoproliferative disease (PTLD) that occurred in the early posttransplantation period. They were Epstein-Barr Virus (EBV)-negative and received graft from EBV-positive donors. The surveillance for EBV viremia using serial EBV polymerase chain reaction determinations in the peripheral blood was positive at 10 and 90 days after OLT concomitant with symptoms of primary infection, both patients were treated with gancyclovir. The patients should progression to a Burkitt's and a non-Hodgkin's lymphoma that appeared 3 months posttransplantation. They were treated by withdrawal of immunosuppression and six courses of cyclophosphamide as well as anti-CD20 monoclonal antibody (Rituximab) every 21 days. One patient experienced acute graft rejection, which resolved with steroids and low doses of tacrolimus, she is free of disease at 24 months after the end of treatment. The other patient relapsed with a cerebral lymphoma, receiving aggressive chemotherapy, but died due to sepsis. In conclusion, PTLD occurred among in 2/23 patients who underwent OLT and appeared in the first quarter post OLT. The risk factors associated with early PTLD were primary EBV infection after OLT, young age, and EBV-negative recipient receiving a transplant from an EBV-positive donor. Antiviral treatment alone was inefficient; withdrawal of immunosuppression and courses of Rituximab and cyclophosphamide were well tolerated and controlled PTLD. The risk of graft rejection was increased by withdrawal of immunosuppression. One patient died.     

Anthracycline-based chemotherapy as first-line treatment in adults with malignant posttransplant lymphoproliferative disorder after solid organ transplantation

BACKGROUND: Recommended first-line treatment for posttransplant lymphoproliferative disorder (PTLD) is reduction in immunosuppressive therapy, irrespective of histopathological type. Second-line treatment with chemotherapy is generally reserved for tumors that fail to respond to reduced immunosuppression. In view of the similarities between monomorphic PTLD and non-Hodgkin's lymphoma in the general population, our policy is to treat monomorphic PTLD with anthracycline-based chemotherapy as first-line treatment. METHODS: A retrospective single-center analysis of 18 adults who developed PTLD following liver or kidney transplantation was undertaken, with particular emphasis on tumor histology, treatment received, and clinical outcome. RESULTS: Of the 18 patients with PTLD, 13 had high-grade malignant lymphoma on diagnostic biopsy and received anthracycline-based chemotherapy and reduction in immunosuppression as first-line therapy. Nine (69%) of the 13 patients achieved complete remission and eight (62%) remained in complete remission five years after diagnosis. There was no graft loss from rejection or drug toxicity. Four (22%) patients had polymorphic PTLD on diagnostic biopsy (of which two were re-classified as monomorphic) and one had a low-grade malignant lymphoma. All five patients were treated by reduction in immunosuppression without chemotherapy and were in complete remission at a median of two years after diagnosis. Overall, complete remission was seen in 14 out of 18 patients (78%) at one year following diagnosis. CONCLUSION: The use of anthracycline-based chemotherapy and reduction of immunosuppression as first-line treatment in adults with monomorphic PTLD is well tolerated and achieves sustained complete remission in around 70% of patients with a low risk of graft loss.     

Plasmacytoma-like posttransplant lymphoproliferative disorder following orthotopic liver transplantation: a case report

Posttransplant lymphoproliferative disorders (PTLDs) are among the most serious and potentially fatal complications of both stem-cell and solid-organ transplantation. Most monomorphic PTLDs are of B-cell origin and frequently associated with Epstein-Barr virus (EBV) infection in the setting of pharmacological immunosuppression posttransplantation. The majority of monomorphic PTLDs commonly resemble diffuse large B-cell or Burkitt's lymphoma; plasmacytoma-like PTLDs are very rare. We report a case of plasmacytoma-like PTLD arising in the allograft in a 66-year-old male diagnosed 2 months following an orthotopic liver transplant for alcohol-related end-stage liver disease. The liver biopsy revealed marked infiltration of atypical plasma cells with lambda light chain restriction and positivity for EBV by in situ hybridization confirming the diagnosis. Also noted was a remarkable increase of tissue eosinophils. Reduction of immunosuppression led to improvement in his clinical condition, and also resolution of the hepatic lesions and abdominal lymphadenopathy noted on imaging studies. While a few cases of plasmacytoma-like PTLDs have been described in literature, to our knowledge, this is the first reported case of early onset plasmacytoma-like PTLD in a liver transplant recipient occurring in the allograft with associated lymphadenopathy having distinct histopathologic features including tissue eosinophilia. Timely recognition of such an entity is critical in order to initiate early and appropriate intervention.     

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.     

Retransplantation after post-transplant lymphoproliferative disease

We present a boy who developed post-transplant lymphoproliferative disease (PTLD) 3.5 months after a first kidney transplant. The diagnosis was made after histopathological examination of the renal graft which was removed because of Pseudomonas aeruginosa septicaemia. After 2 years on dialysis, the patient received a second renal transplant. This graft continues to function after 5 years and there has been no evidence of recurrence of PTLD. This suggests that retransplantation can be undertaken in patients who have recovered from PTLD in a previous graft. Received March 25, 1996; received in revised form October 10, 1996; accepted October 18, 1996     

T-cell posttransplant lymphoproliferative disorder occurring in a pediatric solid-organ transplant patient

Posttransplantation lymphoproliferative disorder (PTLD) is a serious complication seen in transplant patients as a consequence of immunosuppressant therapy. Most cases are of B-cell origin and are commonly associated with Epstein-Barr virus (EBV) infection. T-cell PTLDs are rare and only 13 pediatric T-cell PTLDs with clinicopathologic correlation have been reported previously. We present the histologic, immunophenotypic, and molecular features of a monomorphic PTLD (T-cell lymphoma) identified in a pediatric patient following orthotopic liver transplantation. The lymphoma was identified in the ileum, rectum, and mesenteric lymph nodes. In situ hybridization revealed numerous EBER-1-positive tumor cells. A current review of the literature is also discussed. Of the 14 cases of pediatric T-cell PTLD reported in the literature, only 3 (21.4%) are described as being EBV positive. Most of the reported PTLDs are monoclonal, with 9 of 11 cases (82%) showing a clonal T-cell population by gene rearrangement studies. T-cell PTLD cases appear to have a poor prognosis (11 of 14 patients died of the disease), although patients with involvement of specific anatomic sites may have a better outcome.     

Successful outcome with a "quintuple approach" of posttransplant lymphoproliferative disorder

BACKGROUND: The treatment of posttransplant lymphoproliferative disorder (PTLD) remains empirical. We review our treatment of seven cases of PTLD consisting of five interventions: 1) reduction of immunosuppression; 2) antiviral drugs; 3) interferon-alpha; 4) gamma-globulins; and 5) anti-CD19 monoclonal antibodies. METHODS AND RESULTS; Seven consecutive patients who had undergone a simultaneous pancreas-kidney, liver, heart, or kidney transplantation were treated. One patient acquired a primary EBV infection with an oligoclonal immunoblastic lymphoma early after pancreas-kidney transplantation; all others developed a monoclonal polymorphic or immunoblastic lymphoma 2 to 123 months after transplantation. In all patients extranodal sites were involved, in three the graft was also involved. Five patients received the full quintuple approach and all rapidly obtained a complete remission (CR) with a median follow-up of 31 months (7-74 months). Of the two patients who did not receive interferon-alpha for fear of graft rejection one responded slowly with a CR after 7 months, and the other obtained a rapid CR followed by a relapse at 4 months. All three patients with a liver or heart transplant could keep their graft. All patients are still alive with a median follow-up of 31 months (7-74 months). CONCLUSION: This combined approach resulted in a favorable outcome in patients with high risk monoclonal PTLD after solid organ transplantation.     

Posttransplant lymphoproliferative disorders in adult and pediatric renal transplant patients receiving tacrolimus-based immunosuppression

Between March 27, 1989 and December 31, 1997, 1316 kidney transplantations alone were performed under tacrolimus-based immunosuppression at our center. Posttransplant lymphoproliferative disorders (PTLD) developed in 25 (1.9%) cases; the incidence in adults was 1.2% (15/1217), whereas in pediatric patients it was 10.1% (10/99; P<.0001). PTLD was diagnosed 21.0+/-22.5 months after transplantation, 25.0+/-24.7 months in adults and 14.4+/-18.2 months in pediatric patients. Of the 4 adult cases in whom both the donor and recipient Epstein Barr virus (EBV) serologies were known, 2 (50%) were seropositive donor --> seronegative recipient. Of 7 pediatric cases in whom both the donor and recipient EBV serologies were known, 6 (86%) were EBV seropositive donor --> seronegative recipient. Acute rejection was observed before the diagnosis of PTLD in 8 (53%) of 15 adults and 3 (30%) of 10 pediatric patients. Initial treatment of PTLD included a marked decrease or cessation of immunosuppression with concomitant ganciclovir therapy; two adults and two pediatric patients required chemotherapy. With a mean follow-up of 24.9+/-30.1 months after transplantation, the 1- and 5-year actuarial patient and graft survival rates in adults were 93% and 86%, and 80% and 60%, respectively. Two adults died, 3.7 and 46.2 months after transplantation, of complications related to PTLD, and 10 (including the 2 deaths) lost their allograft 3.7-84.7 months after transplantation. In children, the 1- and 5-year actuarial patient and graft survival rates were 100% and 100%, and 100% and 89%, respectively. No child died; one child lost his allograft 41.3 months after transplantation. One child had presumed recurrent PTLD that responded to discontinuation of tacrolimus and reinitiation of antiviral therapy. The mean serum creatinine level in adults was 2.5+/-1.2 mg/dl, and in children, it was 1.3+/-0.6 mg/ dl. Under tacrolimus-based immunosuppression, PTLD is less common after renal transplantation in adults than in children, but PTLD in children is associated with more favorable outcomes than in adults.     

Successful treatment with rituximab of lymphoproliferative disorder in a child after cardiac transplantation

Post-transplantation lymphoproliferative disorders (PTLDs) are life-threatening complications. We report the case of a 7-year-old girl in whom a lymphoproliferative disorder developed more than 2 years after cardiac transplantation. The patient was taking ganciclovir for Epstein-Barr virus hepatitis at the time the PTLD occurred. Rituximab, an anti-CD20 monoclonal antibody, given in the presence of reduced immunosuppression therapy, resulted in a complete response of the PTLD. The Epstein-Barr viral load in the peripheral blood, which was extremely high at diagnosis, dropped promptly and remained below the detection threshold 11 months after completion of therapy. We observed complete depletion of B lymphocytes until 7 months after rituximab therapy, which was associated with an important decrease in immunoglobulin levels.     

Post-transplant lymphoproliferative disorder following renal transplantation: A single-center experience over 40 years

Objectives:   To investigate post-transplant lymphoproliferative disorder (PTLD) following renal transplantation at our institution.
Methods:   Medical records of 631 patients who underwent renal transplantation at Osaka University Hospital between March 1965 and December 2008 were reviewed.
Results:   PTLD following renal transplantation was detected in 10 patients (five men, five women; mean age at transplantation, 38.5 years). Mean duration from renal transplantation to the onset of PTLD was 7.1 years (range, 5 months to 18 years, 9 months). Mean duration of observation was 3.9 years from the onset of PTLD. Immunosuppressant therapy comprised multidrug combination therapy, including cyclosporine in six patients and tacrolimus in four patients. In addition to a reduction in the immunosuppressant dose, which was performed in all patients, PTLD was treated with surgery in seven patients, radiotherapy in two patients, rituximab in five patients, and cytotoxic chemotherapy in four patients. A complete remission in eight patients and progressive disease in two were observed. At last follow up, seven patients were alive and five patients had functioning grafts.
Conclusions:   The incidence of PTLD following renal transplantation at our institution is 1.6% with onset occurring more than 5 years after transplantation in five patients. Consequently, with long-term renal graft survival now feasible, attention must be paid to detecting late-onset PTLD.     

Anti-CD20 monoclonal antibody treatment of Epstein-Barr virus-induced intrahepatic lymphoproliferative disorder following liver transplantation

Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disorders (PTLDs) are a common cause of death in transplant patients. Their incidence following liver transplantation is reported to be between 0.5% and 4%. Despite various therapeutic approaches, there is still no consensus on a treatment strategy. The treatment of transplant recipients with monoclonal antibodies directed against B-cell antigens is a new, therapeutic approach with which, however, little clinical experience has so far been gained. Two patients developed intrahepatic PTLD 7 and 15 months, respectively, after transplantation. In one case, this was diagnosed as polymorphic PTLD, in the other as monomorphic, monoclonal PTLD. After having their immunosuppression terminated, 4 weeks after establishment of the diagnosis, both patients were treated with anti-CD20 antibodies (rituximab) at a dose of 375 mg/m(2) on days 1, 8, 15 and 22. Treatment with rituximab was tolerated well by both patients. One of the patients in whom cholestasis parameters remained high underwent re-transplantation. In one of the cases, the histological work-up confirmed necrosis of 90% of the tumour cells, and complete remission in the other. Both patients died of secondary complications 10 weeks and 10 months, respectively, after the diagnosis of PTLD. We can conclude that treatment of PTLD with Rituximab led to remission in both of our patients. Nevertheless, progression of cholestasis persisted, and both patients ultimately died of complications unrelated to PTLD.     

Lung retransplantation after posttransplantation lymphoproliferative disorder (PTLD): a single-center experience and review of literature of PTLD in lung transplant recipients.

BACKGROUND: Retransplantation in adult lung transplant recipients developing progressive bronchiolitis obliterans syndrome as a consequence of posttransplantation lymphoproliferative disorder (PTLD) therapy has not been reported in the literature. Literature on PTLD after lung transplantation is limited mostly to case reports or small case series, limiting the validity of conclusions. METHODS: Retrospective chart review of patients at our center. Analysis of pooled data published on lung transplant patients developing PTLD. RESULTS: Two patients who underwent pulmonary retransplants for PTLD have functioning grafts 23 and 36 months postoperatively, with no evidence of PTLD recurrence. Review and analysis of published data and from our center revealed that incidence of PTLD, proportion of patients with thoracic involvement, and proportion of patients who were Epstein-Barr virus seronegative before transplantation decreased continuously as a function of time from transplant. Patients developing PTLD within the first 6 months after transplantation had a clinically distinct pattern of PTLD and a significantly better survival than patients developing PTLD more than 6 months after lung transplant. CONCLUSIONS: Lung retransplantation can be considered after careful selection for lung transplant recipients developing bronchiolitis obliterans syndrome as a consequence of reduced immunosuppression for PTLD. Acquisition of PTLD and pattern of organ involvement is a continuous process as a function of time. Defining "early PTLD" as occurring in the first 6 months more accurately predicts progress and prognosis of this disease than the traditional 1 year definition of early vs late onset PTLD.     

Successful Renal Retransplantation after Post-Transplant Lymphoproliferative Disease

Post-transplant lymphoproliferative disease (PTLD) is a rare but severe complication of renal transplantation. Reduction of immunosuppression is essential for controlling PTLD but may induce graft loss. Retransplantation after PTLD is considered dangerous, because immunosuppressive treatment resumption may trigger hematological relapse. We retrospectively report six patients (five adults, one child) who underwent a second renal transplantation after successfully treated PTLD. Epstein-Barr virus (EBV) serology was positive before the first transplantation in all patients except the child. Post-transplant lymphoproliferative disease was detected 6.6 months (range 4.5-9.4) after transplantation. Lymphoproliferation was always monomorphic, B-cell, and EBV-related. Post-transplant lymphoproliferative disease was confined to the renal allograft (n = 4), multilocular (n = 1) or cerebral (n = 1). Immunosuppression tapering (6/6) and transplantectomy (5/6) led to hematological remission in all patients. Retransplantation was performed 77 months (range 50-128) after PTLD diagnosis. Immunosuppression included steroids (n = 6), ATG (n = 2), anti-CD25 (n = 2), cyclosporine (n = 4), tacrolimus (n = 2), mycophenolate mofetil (n = 4) and azathioprine (n = 1). After a median follow up of 30 months (range 24-47) patient survival was 100%, with no recurrence of PTLD. In conclusion, renal retransplantation can be considered in patients with monomorphic PTLD history, without major risk of hematological recurrence.     

Immunosuppressive TOR kinase inhibitor everolimus (RAD) suppresses growth of cells derived from posttransplant lymphoproliferative disorder at allograft-protecting doses

BACKGROUND: Posttransplant lymphoproliferative disorders (PTLDs) represent a life-threatening complication of standard immunosuppressive therapy. The impact of novel, rapamycin-related immunosuppressive drugs on the pathogenesis of PTLDs remains undefined. METHODS: We tested the effect of everolimus (RAD, Novartis Pharma AG, Basel, Switzerland) on human PTLD-derived cells using in vitro assays and an in vivo severe combined immunodeficiency disease mouse xenotransplant model. RESULTS: Everolimus profoundly inhibited the proliferation, cell-cycle progression, and survival of the PTLD-1 cell line established from a pulmonary PTLD. Equally profound inhibition of PTLD-1 growth was achieved in vivo at well-tolerated everolimus doses of 0.5 to 5 mg/kg per day. Five mg/kg per day of everolimus, given once per day, inhibited PTLD-1 tumor volume gain by more than 10-fold in treated mice compared with untreated mice. Because the subsequent pharmacokinetic analysis indicated rapid everolimus absorption, distribution, and clearance in mice (with a half-life of 3 to 6 hr and maximum drug blood concentration reached after 0.5 to 1 hr), treatment was changed to a twice-daily regimen. Everolimus given twice daily at 0.5 mg/kg per dose inhibited tumor-volume gain by more than 60-fold and at 0.25 mg/kg per dose by more than 10-fold. Similar everolimus doses were required to prevent graft rejection in a mouse heart allotransplantation model; the highest dose tested (1.5 mg/kg twice daily) resulted in long-term graft survival in all mice that underwent transplantation. CONCLUSIONS: Everolimus displays a potent inhibitory effect on PTLD-derived cells in vitro and in vivo in a dose range leading to prevention of allograft rejection and may prove effective in both the prevention and treatment of PTLDs in transplant patients.     

Association of the type of induction immunosuppression with posttransplant lymphoproliferative disorder, graft survival, and patient survival after primary kidney transplantation

BACKGROUND: The use of antilymphocyte antibodies for induction therapy or for treatment for rejection has been associated with an increased risk of posttransplant lymphoproliferative disorder (PTLD). The authors investigated the incidence of PTLD after monoclonal antilymphocyte, polyclonal antilymphocyte, interleukin (IL)-2 receptor antibody, or no induction therapy in primary kidney transplant recipients. METHODS: A multivariate Cox analysis of 38,519 primary kidney transplants from January 1, 1997, to December 31, 2000, was performed to compare the incidence of PTLD, graft survival, and patient survival among the induction groups. RESULTS: The actual incidence of PTLD was 0.85% in 2,713 recipients with monoclonal, 0.81% in 4,343 with polyclonal, 0.50% in 7,800 with IL-2, and 0.51% in 23,663 recipients with no induction therapy (P=0.02). The Cox model indicated that as compared with no induction, the increased risk of PTLD was 72% with monoclonal (P=0.03), 29% with polyclonal (P=0.27), and 14% with IL-2 induction (P=0.52). IL-2 receptor antibody was associated with a 17% reduced risk of graft loss (P=0.002) and a 21% reduced risk of mortality (P=0.005) compared with no induction. Monoclonal and polyclonal induction therapies were not associated with a reduced risk of graft loss or mortality. Mycophenolate mofetil discharge maintenance immunosuppression was associated with a significantly reduced risk of PTLD and graft loss compared with azathioprine. CONCLUSIONS: Among induction therapies, IL-2 receptor antibody induction was associated with the smallest risk of PTLD and improved graft and patient survival. Monoclonal or polyclonal induction was not associated with improved graft or patient survival, and monoclonal induction was associated with an increased risk of PTLD.