PF307 POST-TRANSPLANT LYMPHOPROLIFERATIVE DISORDER IN LIVER AND KIDNEY TRANSPLANT RECIPIENTS OVER 33 YEARS: A SINGLE-CENTRE EXPERIENCE

Background: Post-transplantation lymphoproliferative disorders (PTLD) are a rare complication of transplantation, although with the increasing number of transplantations this paradigm is changing. Studies describe a peak in PTLD incidence in year 1 post-transplant, and some describe a second peak after 8–10 years. PTLD incidence beyond the 10th year is not well characterized.1 Early-onset of PTLD is frequently related with induction immunosuppression and is often characterized by EBV positivity. Late PTLD (more than 2 years after transplantation) is related with cumulative immunosuppression2. A large multicentre study revealed that 80 PTLD patients after solid organ transplant, whose the majority (80%) received rituximab-based treatment, had a 3-year overall survival (OS) of 62%.3 Aims: To review the prevalence of PTLD in a kidney and liver transplantation centre, time from transplant to diagnosis and outcome. Methods: Data were retrospectively collected from PTLD patients who underwent liver (LT) and kidney transplant (KT) at our centre between January 1985 and December 2018. KT patients received induction immunosuppression followed by maintenance with glucocorticoids, calcineurin inhibitors (CNI) and antimetabolite agent. LT patients received mainly maintenance monotherapy immunosuppression with CNI. As initial management of all patient with PTLD, immunosuppression was reduced, suspended or switched to mTOR inhibitors. The treatment was chosen according to the best practise at the time of diagnosis. Results: Among 2667 KT patients, 33 (1.2%) had PTLD, 22 were male, with a median age at transplantation of 37 years (range 14–64). Median time from transplant to PTLD diagnosis was 11.9 years (range 0.08–27.67), 29 patients (88%) had late PTLD and 17 (52%) were diagnosed ≥10 years from transplant. The overall OS at 3 years was 49%. Monomorphic PTLD was the most frequent diagnosis (25 patients, 75%): 16 had Diffuse Large B Cell Lymphoma (DLBCL), 3 had high grade lymphoma (HGL), not otherwise specified and the remaining 6 had other diagnosis. Nine of the 19 patients diagnosed with DLBCL/HGL were treated with Rituximab based chemotherapy (R-CT) and their 3-years OS was of 35%. Among 1211 LT patients 9 (0.7%) had PTLD, 7 were male, with a median age at transplantation of 50 years (range 21–60). Median time from transplant to PTLD diagnosis was 4.5 years (range 0.06–17.8). Six (67%) patients were diagnosed with late PTLD, 2 more than 10 years from transplant. Four had monomorphic PTLD, 3 DLBCL and 1 Burkitt Lymphoma, 2 patients were treated with R-CT and 2 with A-CT. The LT patients with PTLD had a 3 years OS of 40%. In respect to all 42 patients, with a median follow-up of 2.2 (range 0.01–20.5) years the OS at 3 years is 50%. Summary/Conclusion: We performed an analysis of the PTLD incidence in KT and LT patients in a single centre. Given the retrospective nature and the large period of data collection of this study, our incidence may be underestimated. We observed a higher incidence of PTLD in KT patients compared to LT, which is according to literature. Of those, more than half were diagnosed at least 10 years from transplantation, suggesting that maintenance immunosuppression might be the main reason for PTLD is this cohort. Patients diagnosed with DLBCL/HGL and treated with R-CT had a 3-years OS of 35%, representing a poorer outcome than what is described in literature3.