Posttransplantation lymphoproliferative disorders in renal transplant recipients: report of over 20 years of experience.

INTRODUCTION: Despite the benefits of immunosuppressive medications to improve graft function, they have several adverse effects, such as development of neoplasms in renal transplant recipients. Posttransplantation lymphoproliferative disorders (PTLDs) are not uncommon complications, so we conducted a study to evaluate the characteristics of affected patients.

METHODS: We enrolled 2117 kidney recipients from June 1984 to March 2004 in order to find pathological and clinical evidence of neoplasms. We collected and analyzed all data on PTLD patients.

RESULTS: Overall there were 46 recipients with different types of neoplasms, among which the most common types were diseases of the skin (24 cases, 52.2%), Kaposi's sarcoma (15 cases, 32.6%), and PTLD (14 cases, 30.4%). The mean (+/- SD) age of PTLD patients at the time of transplantation was 37.86 +/- 9.67 years and 42.8% were women. Median and mean (+/- SD) time interval to PTLD diagnosis were 38.5 and 50.35 +/- 41.7 months, respectively (range 1 to 146 months). Types of PTLD in these patients were kidney lymphoma (14.3%); gastrointestinal (14.3%); brain lymphoma; tonsils; palatine; Hodgkin's lymphoma, large cell lymphoma, and acute lymphoblastic lymphoma (each 7.1%), with 28.6% unspecified types. The 1-, 5-, and 10-year patient survival rates after transplantation were 71.4%, 51.4%, and 44.3%, respectively. Despite discontinuing immunosuppressive therapy in PTLD patients, five of six surviving had graft function up to a mean time of 105.4 +/- 57.6 months after transplantation.

CONCLUSION: Our findings showed that the prevalence of PTLD was 0.66%, which was less than reports from Western countries. The fact that there were surviving grafts for a considerable time despite discontinuing immunosuppressive therapy is of great importance.