Lymphoproliferative disorders after organ transplantation in children

Background. After organ transplant, patients are at risk of posttransplant lymphoproliferative disorders (PTLD). The purpose of this study was to analyze 26 pediatric cases of PTLD observed at our institution between 1988 and 1996, and to evaluate the validity of the Society for Hematopathology Workshop (SHPW) 1997 classification in our patient population. Methods. Charts were reviewed for analysis of incidence, clinical course, and outcome. Tissue samples were classified by a pathologist according to SHPW recommendations. Results. By morphology, 20 were monomorphic, 5 polymorphic, and 1 hyperplastic. Assessment of lineage by morphology, molecular studies, and immunophenotyping did not correlate in six cases. By immunophenotyping, 12 were B cell, 4 T cell, 8 mixed B/T cells, and 2 undetermined. The 20 patients evaluable for treatment efficacy were treated with various therapeutic combinations, including immunosuppressive drug reduction, acyclovir/ganciclovir, interferon-α, immunoglobulins, surgery, and local irradiation. No patient received systemic chemotherapy. Thirteen patients achieved complete remission and 3, partial; 1 died 5 days after starting therapy, and 3 of progressive disease. Adverse prognostic factors included low platelet or neutrophil counts; stage III-IV and SHPW morphology were marginally significant. Conclusions. The majority of patients eligible for treatment can be cured with immunosuppressive drug reduction and antiviral drugs, along with surgery and irradiation when indicated. Systemic chemotherapy or innovative approaches may have a role in unresponsive cases. Morphologic SHPW grouping is feasible and seems to have clinical relevance. However, correlation with clonality and immunophenotyping is not always possible, necessitating modifications including segregation of descriptive morphology from clonality and cell origin.