Infectious Complications and Mortality in Post-Transplant Lymphoproliferative Disorder Following Solid Organ Transplantation: Experiences of 10 Years in a Single Center

Background: Chronic immunosuppression in solid organ transplant recipients leads to B- and T-cell depletion, which increases the risk of somatic driver mutations that drive monoclonal lymphocyte proliferation. Paradoxically, this impairs cellular immunity, leading to increased susceptibility to both bacterial and viral pathogens. Methods: This retrospective cohort study evaluated solid organ transplant recipients diagnosed with post-transplant lymphoproliferative disorder (PTLD) at the Cleveland Clinic Foundation between January 1, 2010, and December 30, 2021. Patients aged ≥18 years with infection data available for at least one-year post-PTLD diagnosis were included, excluding hematopoietic stem cell transplant recipients. Data on PTLD subtype, Epstein-Barr virus (EBV) status, infectious complications, and outcomes were analyzed using univariate analysis (Pearson’s χ² test) and multivariable logistic regression to identify predictors of infections and mortality. Results: Among 98 PTLD cases, the median onset was 7.03 years post-transplant. EBV-positive PTLD had an onset of 6.97 ± 7.21 years, whereas EBV-negative cases occurred later (8.06 ± 5.24 years). Monomorphic PTLD (94.9%), particularly diffuse large B-cell lymphoma (DLBCL, 63.3%), was predominant. Infections occurred in 60% of patients post-PTLD, with bacterial (41.25%), viral (31.66%), fungal (25.9%), and parasitic (1.19%) infections. At one year, infection-related mortality (48%) exceeded PTLD progression-related deaths (36%). Conclusion: PTLD presents with a complex interplay of immunosuppression, malignancy, and infection. Infections, particularly bacterial infections, are major causes of morbidity and mortality. These findings highlight the need for vigilant infectious disease surveillance and tailored interventions to reduce infection-related mortality and improve outcomes in high-risk populations.