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

[Effects of viral infection on transplant recipients]

Viral infection remains an important cause of morbidity and mortality in transplant recipients. The risk of viral infection in these patients depends on several factors, such as the type of organ transplanted, the intensity of immunosuppression, and the recipient's susceptibility. In additional to direct effects, viral infection cause indirect effects, including greater risk of replication of other viruses, graft rejection, opportunistic infections and other specific entities for each type of transplant. These indirect effects result from the immunomodulatory activity of some viruses, such as cytomegalovirus and human herpes virus-6. For the most part, quantitative molecular tests have replaced serologic testing and in vitro culture for diagnosing infection. This approach is particularly prominent for cytomegalovirus, Epstein-Barr virus, hepatitis B virus, and hepatitis C virus. Despite these diagnostic advances, the development of specific antiviral agents and effective antiviral vaccines is limited. Thus, prophylactic strategies are still essential in transplant recipients.

A late-onset Epstein-Barr virus-related lymphoma completely remitted in a child with renal allograft

Lymphomas are frequently encountered malignancies following renal transplantations. A 17-year-old boy was found to have lymphoma 1.5 years after a the first cadaveric transplantation performed due to reflux nephropathy. Polyclonal anti-thymocyte globulin (induction) with prednisolone (PRD), azathioprine (AZT), and tacrolimus (Tac) regimen had been given after the transplantation. A hypoechoic mass (25 mm) was detected in the upper pole of the allograft by renal Doppler ultrasound performed due to graft dysfunction with a high basal serum creatinine (Cr) (2.2 mg/dL). The renal biopsy revealed a large B-cell lymphoma with CD20 staining in the medulla. The serum displayed a positive Epstein-Barr virus (EBV), immunoglobulin (Ig)G, negative IgM with negative DNA-polymerase chain reaction. However, the biopsy was positive for EBV-LMA. The viral status at the time of transplant was unknown. After withdrawing AZT and Tac therapies, a chemoimmunotherapeutic regimen consisting of PRD, cyclophosphamide, and anti-CD20 monoclonal antibody was administered twice. The patient excreted the necrosed tumor particles over a 2-month interval with hydronephrotic colic attacks. The basal Cr improved at 6 months (to 1.4 mg/dL). A low dose of Tac (0.5 mg/d) was added to PRD. The patient has remained in complete remission for 2.5 years with a well-functioning renal allograft. Although this case was a late-onset lymphoma, the patient displayed a picture like excreting stones from the allograft and remitted completely. This case illustrates that localization of a tumor may play a more important role than the elapsed time from transplant in the diagnosis in EBV-related posttransplant lymphoproliferative disease.

Rituximab in the management of post-transplantation lymphoproliferative disorder after solid organ transplantation: proceed with caution

The introduction of single-agent rituximab has markedly changed the approach to therapy of patients with post-transplantation lymphoproliferative disorder (PTLD), but response to treatment varies substantially between patients. In the current report, we analyze long-term efficacy of single-agent rituximab in 60 patients and present factors predictive of progression-free and overall survival. Twelve months after completing first-line treatment, 34 of 60 patients (57%) had progressive disease, resulting in a median progression-free survival of 6.0 months at a median follow-up of 16.3 months. Using multivariate Cox regression analysis, the following factors were identified as significantly predictive of overall survival: age at diagnosis, performance status, lactate dehydrogenase (LDH), and time from transplantation to PTLD. Stage of disease and Epstein-Barr virus association of PTLD did not influence overall survival. LDH and time from transplantation to PTLD were also predictive of progression-free survival. The international prognostic index was shown to be of limited predictive value in these patients, but a PTLD-specific prognostic index separated low-, intermediate-, and high-risk patients with high significance: 2-year overall survival rates after first-line treatment with single-agent rituximab were 88, 50, and 0%, respectively. Thus, prognostic indices can be useful tools for prediction of treatment outcome and for the development of risk-adapted treatment strategies in patients with PTLD and may also provide the basis for interstudy comparisons.

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.

Post-transplant lymphoproliferative disorders occurring after renal transplantation in adults: report of 230 cases from the French Registry

Post-transplant lymphoproliferative disorders (PTLD) are a rare but serious complication after organ transplantation. A French Registry of PTLD was set up in a nationwide population of kidney transplant recipients. We prospectively enrolled all adult kidney recipients developing PTLD between January 1, 1998, and December 31, 2003. We analyzed the incidence, risk and prognostic factors of PTLD by Kaplan-Meier and Cox analyses. Totally 230 cases of PTLD were referred to the French Registry. Cumulative incidence was 1.18% after 5 years. Older age (per year, AHR = 2.19, CI = 1.22-3.94) and recipient Epstein-Barr virus seronegativity (AHR = 3.01, CI = 1.57-5.08) were associated with an increased risk of PTLD. Patients with PTLD had a reduced survival rate (61% at 5 years). Graft PTLD had the best prognosis with an 81% survival rate after 5 years. Infection with hepatitis C or B virus (HCV or HBV), late-onset PTLD, multiple sites involvement and high Ann Arbor staging were risk factors for patient death. Use of azathioprine was associated with a poorer survival rate. PTLD incidence and risk factors in French recipients are in line with the international or American PTLD series. We highlighted the role of HBV or HCV in patient mortality and described the relevant prognosis factors for patients with post-transplant lymphoproliferations.

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How useful is PET/CT imaging in the management of post-transplant lymphoproliferative disease after liver transplantation?

Post-transplant lymphoproliferative disease (PTLD) is a serious and potentially life-threatening complication after solid organ transplantation. Here, we report our first experience with the use of PET/CT (positron emission tomography combined with computed tomogram) for the management of patients with PTLD after liver transplantation. Four patients with histologically proven PTLD were analyzed. Conventional work-up included physical examination and head-to-pelvis CT. PET/CT was used in one patient for initial staging and in all patients for follow-up. PET/CT positive findings underwent biopsy. Information provided by PET/CT resulted in a change of medical management in three of the four patients. Conventional work-up missed residual disease after surgery in one and failed to detect a tumor relapse in another patient. However, one patient disclosed a false positive PET/CT finding in the lungs. In conclusion, PET/CT may be a useful tool for staging and therapy monitoring of PTLD after liver transplantation.

FDG PET imaging in the evaluation of post-transplant lymphoproliferative disorder following renal transplantation

OBJECTIVES

To assess the usefulness of fluorodeoxyglucose positron emission tomography (FDG PET) in the evaluation of post-transplant lymphoproliferative disorder (PTLD) following renal transplantation.

METHODS

Staging FDG PET examinations were reviewed in five patients with biopsy proven post-renal allograft PTLD and compared with conventional imaging. Follow-up PET examinations of three patients at various points during their therapy for PTLD were also reviewed and compared with clinical outcome.

RESULTS

PET imaging identified all disease sites seen at cross-sectional imaging, clarified sites of uncertain significance and detected additional disease in two out of five patients. Early follow-up imaging impacted PTLD management in two of three patients.

CONCLUSION

In this limited series FDG PET was an effective imaging modality in the staging and follow-up of PTLD.