Methods and objectives of a large US multicenter case-control study of post-transplant lymphoproliferative disorder in renal transplant patients.

A large multicenter case-control study is in progress in the United States, the primary goal of which is to provide information about the effects of specific immunosuppressants and other risk factors on posttransplant lymphoproliferative disorder (PTLD) in renal transplant patients. It will also provide incidence data and case characterization on PTLDs arising in a large contemporary population. Medical record data are being collected on up to 120 PTLD cases and up to four controls per case transplanted at 20 large US centers. Participants all received transplants on or after July 1, 1995 and PTLD cases will be identified through December 31, 2001. All cases undergo central clinical and pathologic review. Abstracted information includes detailed data (dosages, duration) on all immunosuppressants (induction, maintenance, anti-rejection) as well as antiviral treatment. Other data include demographics, transplant history, HLA matching and viral status (e.g., Epstein-Barr virus, cytomegalovirus). Information associated with the PTLD diagnosis and initial therapy for PTLD is also collected. To date, 86 potential cases have been reported. Twenty (24%) are pediatric patients (< or =18 years). Median time between transplant and PTLD is 268 days; 53 (62%) were diagnosed within the first year. Cumulative incidence through 1998 is 0.7% for adults and 4.5% for children. The most common single site for PTLD is the allograft. Common treatments included either a reduction or discontinuation of immunosuppression (90%) and antiviral treatment (66%). Overall, the allograft appears to be an important site of PTLD recurrence. Also, the incidence of renal PTLD since the introduction of new immunosuppressive therapies is similar to that reported earlier.