Posttransplantation lymphoproliferative disorders in pediatric patients undergoing liver transplantation

Trisomy 3, a sole recurrent cytogenetic abnormality in pediatric polymorphic post-transplant lymphoproliferative disorder (PTLD)

Trisomy 3 has been previously reported in association with T-cell lymphomas and less commonly in different types of non-Hodgkin B-cell lymphomas. Trisomy 3 has also been reported in two cases of pediatric post-transplant lymphoproliferative disorder (PTLD). We present comprehensive clinicopathologic review of two pediatric patients with cardiac and liver/intestinal allografts that developed polymorphic PTLD characterized by trisomy 3. Both patients had Epstein-Barr virus (EBV) viremia and EBV was positive in tissue by EBER in situ hybridization. Using karyotype analysis and fluorescence in situ hybridization, we identified trisomy 3 in both patients. Both patients responded to treatment and are now free of the PTLD. Trisomy 3, an uncommon cytogenetic finding in pediatric polymorphic PTLD, may be a recurrent cytogenetic aberration if confirmed in a larger study of pediatric PTLDs. Further clinical follow up might help stratify significance of trisomy 3 as a prognostic factor.

CD20 expression predicts survival in paediatric post-transplant lymphoproliferative disease (PTLD) following solid organ transplantation

The prognostic role of CD20 expression and Epstein-Barr virus (EBV) positivity in post-transplant lymphoproliferative disease (PTLD) after solid organ transplantation (SOT) in paediatric patients is poorly understood. We retrospectively examined the relationship of CD20 and EBV with the time interval from SOT to PTLD diagnosis, and PTLD-related event-free (EFS) and overall survival (OS) in 45 consecutive PTLD patients (≤25 years) following SOT. These 45 paediatric SOT patients (28 heart, 11 liver, six kidney) were diagnosed with PTLD 45 months (mean; SD 43; range 4-153; median 24·5) after SOT, with PTLD diagnosis at 118 months (mean) (SD 77; range 14-287) of age. Of 40 evaluable tumours (11 monomorphic, 19 polymorphic, five early lesions, five rare subtypes), 32 (80%) had detectable EBV and 28 (70%) were classified as CD20(+) . Patients whose PTLD expressed CD20 or EBV had shorter intervals between SOT and PTLD onset (28 vs. 64 or 77 months for CD20 and EBV respectively) (P < 0·02), even after adjusting for age at SOT. Patients with CD20(+) tumours had higher 5-year PTLD-related EFS (83·7% vs. 28·6%, P < 0·001) and OS (95·8% vs. 56·3%, P = 0·01). EBV expression was unrelated to PTLD-related EFS or OS. CD20 expression is associated with timing of development of PTLD and predicts survival in PTLD diagnosed following paediatric SOT.

Tonsil enlargement after liver transplantation in adults--reason enough for tonsillectomy? Two cases of tonsillar posttransplantation lymphoproliferative disease

Posttransplantation lymphoproliferative disease (PTLD) is a well-known complication of solid organ and bone marrow transplantation. It is agreed that the main causes of PTLD are chronic infection with Epstein-Barr virus (EBV); the intensity, rather then the type, of immunosuppression used; and underlying recipient disease. Hepatitis C virus (HCV) and cytomegalovirus, as cofactors of EBV infection, have been suggested to increase the risk of PTLD. Use of calcineurin inhibitors, anti-CD3 monoclonal antibody (OKT3), and antithymocyte globulin may increase the risk of PTLD. On the other hand, mycophenolate mofetil, sirolimus, and the anti-interleukin-2 receptor monoclonal antibodies Daclizumab and basiliximab have not been demonstrated to increase the risk of PTLD. The incidence of PTLD after liver transplantation (LT) is estimated to be 1.5-3%, but a tonsillar location is extremely rare in adults. Thus, little is known about the best diagnostic tools for and treatment by LT recipients with tonsillar PTLD. Here, we report 2 cases of adult LT recipients with tonsillar PTLD. Tonsillectomy was used as a diagnostic tool and treatment option and resulted in complete remission for >2 years. Considering the high mortality and diagnostic difficulties of PTLD, together with the relatively low risks of tonsillectomy, we recommend tonsillectomy for treating tonsil enlargement of unknown cause and suspected PTLD in LT recipients. A larger series of patients and prospective studies comparing different treatment options will be needed to substantiate our recommendation.

A case of laryngeal posttransplantation lymphoproliferative disease

The development of posttransplant lymphoproliferative disease (PTLD) is strongly linked to infection with the Epstein-Barr virus (EBV), immunosuppression-state, the type of allograft, and EBV-seronegativity. A 18-month-old girl who had undergone living donor liver transplantation using the left lateral segment from her father was treated with tacrolimus and corticosteroid as an immunosuppressant regimen. She was readmitted 3 months after the transplant to evaluate the etiology of dyspnea and abdominal fullness as well as a decreased urine volume. She was diagnosed as an anastomotic stenosis of the hepatic vein for which she underwent balloon angioplasty. The treatment was repeated at postoperative month 5, 8, and 11. As postoperative 6 months, the result of the serological EBV-CA (IgG/IgM) was positive. In postoperative month 10, the EBV PCR serologic test become positive, and a laryngeal biopsy revealed PTLD. She was treated with acyclovir and gangyclovir as well as reduced immunosuppression. We report herein a rare case of laryngeal PTLD in a patient who had undergone living donor liver transplant with paternal allograft.

Diagnosis of Epstein-Barr virus-associated diseases

Epstein-Barr virus (EBV) is a common DNA virus distributed worldwide. Usually the initial infection involves the upper respiratory tract without any problems and almost the entire population more than 25 years old test positive for anti-EBV antibodies. However, EBV often causes not only acute lytic infection but also chronic active infection with B cells and even T cells. In addition the EBV genome has been detected in tumors of hematopoietic or epithelial cell origin such as Burkitt's lymphomas, Hodgkin's disease, NK/T cell lymphomas, nasopharyngeal carcinomas (NPCs) and gastric adenocarcinomas. It is clearly important to make a correct diagnosis for EBV associated diseases and monitor the EBV load in individual patients for an appropriate therapy. In this paper recent advances in serological, immunological and molecular approaches for detection of EBV associated disease are described.

Common diagnostic problems in pediatric liver pathology

The role of the pathologist in dealing with common problems of liver disease in children is likely to change dramatically as the molecular genetic revolution progresses. For example, microchip arrays for genes involved in bile salt synthesis and transport will pinpoint the specific mutations responsible for infantile cholestasis and similar methods will sort out infectious agents of acute and chronic hepatitis. But even as biochemistry, microbiology, and immunology laboratories already provide essential diagnostic information in such settings, informed histopathologic interpretation will continue to guide investigations of etiology and therapeutics and will remain an important medical necessity [95,96,100,102,104].