Rising incidence of post-transplant lymphoproliferative disease in kidney transplant recipients G. Libertiny, C. J. E. Watson, D. W. R. Gray, K. I. Welsh and P. J. Morris Oxford Transplant Centre, Churchill Hospital, Headington, Oxford, UK Correspondence to: Mr G. Libertiny, Nuf®eld Department of Surgery, Level 6, John Radcliffe Hospital, Oxford OX3 9DU, UK e-mail: gabor.libertiny@surgery.oxford.ac.uk) Background: The purpose of this study was to determine whether the incidence of post-transplant lymphoproliferativediseasePTLD)hasbeenincreasinginrenaltransplantrecipientsinthiscentre. Methods: ProspectivelygathereddatawereanalysedtoestablishtrendsintheepidemiologyofPTLDin 1537patients. Results: Overall, PTLD occurred in 2´3 per cent of renal transplant recipients. An increase in its incidence coincided with the introduction of cyclosporin in the 1980s. However, there was a further increaseintheincidenceofPTLDinthe1990swhentheonlychangeinimmunosuppressivepolicywas the abandonment of pretransplantation blood transfusion. The latter increase was particularly pronounced in patients with early-onset PTLD in whom it presented within 600 days after transplantation. Conclusion: The incidence of PTLD has been increasing in renal transplant recipients. The recent increase appears to be independent of cyclosporin and may re¯ect the reduction in pretransplant blood transfusion. Changes in the incidence of PTLD may also mirror changes in the epidemiology of non- Hodgkinlymphomainthegeneralpopulation. Paper accepted 23 July 2001 British Journal of Surgery 2001, 88, 1330±1334 Introduction The risk of developing malignancy in immunosuppressed organtransplantrecipientsismarkedlyincreasedcompared withthatinthegeneralpopulation 1 .Afterskincancer,post- transplant lymphoproliferative disease PTLD) is the most common such malignancy with a 28±49-fold increase in incidence compared with non-Hodgkin lymphoma in the general population 2 . PTLD carries a high mortality rate that approaches 70 per cent 3 . It occurs in 0±2´5 per cent of patients following renal transplantation 2 . The risk of developing PTLD differs according to the transplanted organ;theriskislowestfollowingrenaltransplantationand increases if the transplanted organ is heart, liver or heart± lung 4 . This difference may re¯ect the organ type, the level of immunosuppression used, and exposure to other recognized risk factors such as Epstein±Barr virus 3 . The type of immunosuppression also in¯uences the risk of developing PTLD: cyclosporin-based regimens are asso- ciated with a higher risk than regimens containing only steroid and azathioprine 5,6 . Furthermore, PTLD develops sooneraftertransplantationinpatientstakingcyclosporin 6 . A recent increase in the number of patients presenting with PTLD prompted an examination of trends in its epidemiology in renal transplant recipients. Patients and methods Data of patients with PTLD diagnosed before June 1998 were obtained from the Oxford Transplant Centre Database, which includes a tumour registry and a large prospectivelygathereddatabaseofall1537renaltransplants performed between January 1975 and June 1998. PTLD wasdiagnosedbyaconsultantpathologist.Thediagnosisof alymphoidneoplasmwasbasedonthemorphologyand,in most cases, immunophenotyping of tissue samples Table 1.) The notes of patients found to have had lymphoma were studied in detail. Thirty-six patients, who arrived from overseas for living donor transplantation and werelosttofollow-upafterreturningtotheircountry,were excluded from the study. The follow-up on the remaining 1501 patients was 100 per cent complete, including all deaths and failed grafts. As the incidence of PTLD did not differbetweenmenandwomen,orinrecipientsof®rstand Association of Surgeons 1330 ã 2001 Blackwell Science Ltd British Journal of Surgery 2001, 88, 1330±1334