Post‐transplant lymphoproliferative disorders (ptld) after solid organ transplantation (sot): 15 years of monocentric experience in a referral centre

Background: Post-transplant lymphoproliferative disorder (PTLD) is a rare complication of solid organ transplantation (SOT) and is composed of a heterogeneous spectrum of predominantly B-cell disorders. Epstein-Barr Virus (EBV) is involved in a substantial number of cases. In this single Center retrospective analysis we described our PTLD series. Methods: PTLD after SOT were identified by Electronic Medical Records database of our Department. Inclusion criteria were age ≥18 years at the time of diagnosis, PTLD occurrence from 2007 to 2022 and receipt of therapy at Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy. Results: A total of 34 PTLD patients were followed for a median of 23 months (Inter Quartile Range: 8–80 months). With a median age at diagnosis of 46 years (range 18–82 years), 59% (20/34) were male. The half of patients were ≥50 years old at PTLD onset. The overall median time from SOT to PTLD was 6.1 years. Considering organ, 41% of patients received liver, 38% kidney and 21% lung respectively. Median time from graft to PTLD diagnosis was 3 months for lung, 99 and 101 months for liver and kidney transplantation respectively. Regarding EBV status, 62% (13/21) of patients presented associated EBV infection. Histologic PTLD diagnosis are reported in Table 1. Only 32% of patients received reduction of immunosuppression (RIS), 24% were treated with rituximab monotherapy and 82% underwent chemo/chemo-immunotherapy because of aggressive disease or failure of response with previous treatment. At the time of analyses, 38% (13/31 of patients were alive. The median survival time was 35 months (Figure 1A). Lung transplanted showed higher mortality than kidney ones (hazard ratio (HR) 2.3, 95% confidence interval (CI) 0.6-8.7). At PTLD diagnosis, lung recipients were more frequently EBV-DNA positive (6/7) than those liver transplanted (1/11) (p = 0.001). EBV-DNA positivity was associated with mortality (HR 1.9, 95% CI: 0.7-5.4), but a joint analysis of the role of transplanted organ and EBV-DNA status is not feasible because of sparse data. Neither RIS nor rituximab treatment (Figure 1B,C), but first-line chemo/chemo-immunotherapy were predictive of better survival (HR 0.4, 95% CI: 0.9-1.7) (Figure 1D). Keyword: aggressive B-cell non-Hodgkin lymphoma No conflicts of interests pertinent to the abstract.