P1685POST-TRANSPLANT LYMPHOPROLIFERATIVE DISORDER (PTLD): SINGLE INSTITUTIONAL EXPERIENCE OF TWO DECADES

Abstract

Abstract Background and Aims Post-transplant lymphoproliferative disorders (PTLD) are a group of heterogeneous lymphoid proliferations in chronic immunosuppressed recipients of solid organ and hematopoietic stem cell transplantation. Due to rarity of this disease, retrospective studies from transplant centers have been the main source to provide knowledge and treatment guidelines, which are still in evolution. This study examined the clinical outcomes and identified the predictors of mortality in adult renal transplant recipients who developed PTLD. Method We have studied the incidence of PTLD in adult renal transplant recipients who were transplanted in our hospital from 1996 to 2019. Data was collected for demographics, transplant and immunosuppression history, EBV and CMV serostatus, diagnosis, treatment and outcomes of PTLD. We performed univariate and multivariate analysis to identify prognostic factors. PTLD was classified according to 2018 WHO lymphoma classification. Results Twenty-four patients (12 males and 12 females) were eligible for the analysis. Mean age at time of the transplant was 43.1 ± 16.9 years, with a time between grafting and PTLD of 66 months (IQR 36-98 months). Mean follow-up time was 87 months (IQR 61-117 months). 25% of patients received a living donor renal transplant. 12,5% of patients received induction therapy with thymoglobulin. Mean age at time of PTLD diagnosis was 48,8 ± 17,9 years. Five cases were from Epstein-Barr virus (EBV) mismatched (D+/R-) transplants and there was seroconversion at time of PTLD diagnosis. 25% of patients had central nervous system involvement. 19 patients have monomorphic PTLD and the most common histological diagnosis was diffuse large B cell lymphoma. We identified that age >30 years at time of the transplant was predictor of mortality (HR 33.01; 95% CI: 3.24-336.14; p=0.003). Surprisingly, presence of B symptoms at time of PTLD diagnosis confer a better prognosis (HR 0,143; 95% CI: 0,035-0,579; p=0.006). All cases were managed with reduction in immunosuppression and converted to everolimus. 8 patients were treated with rituximab and there was no significant difference in the survival of these patients. By the end of follow-up, 7 patients went into remission, 1 returned to chronic dialysis, and 16 patients died (15 of them due to the disease). Mean time between PTLD and death was 3 months (IQR 1-6 months). Conclusion PTLD is an infrequent disease with a poor prognosis in renal transplant patients. Some cases have a close relationship with EBV, but it can also develop in the absence of the classical risk factors. The factor affecting mortality in our population was age >30 years at time of the transplant. Presence of B symptoms at time of PTLD diagnosis seems to confer a better prognosis probably due to early investigation and diagnosis of the disease.