Characteristics and Outcomes of Alberta Lymphoma Patients with a History of Immunosuppressive therapy for Autoimmune Conditions.

Abstract

Other iatrogenic immunosuppression associated lymphoproliferative disorders (Oii-LPD) is rare subset of lymphoma. There are limited published data on the clinical characteristics and outcomes of this patient population. The primary objective of this study was to describe the clinical characteristics and outcomes of Alberta patients diagnosed with lymphoma following immunosuppressive therapy for autoimmune conditions. Secondary objectives included describing the incidence of Oii-LPD, proportions of subtypes of lymphoma diagnosed and the nature of immunosuppressants used. The outcomes of patients with iatrogenic immunodeficiency-associated diffuse large B cell lymphoma (DLBCL) were compared against a matched control group of patients with de novo DLBCL. The study is a descriptive retrospective cohort study with a matched historical control comparison for patients with DLBCL. Alberta lymphoma patients, diagnosed from January 2011 to December 2019, with a history of iatrogenic immunosuppression were identified and described. The incidence of Oii-LPD was 1% of total Alberta lymphoma cases. Majority of this cohort were diagnosed with DLBCL (54.9%) and the most common immunosuppressive agents were methotrexate (62%), hydroxychloroquine (42%), and TNF inhibitors (31%). Survival was not different between Oii-LPD DLBCL and de novo DLBCL with 5-year survival rates of 64.1% and 67%, respectively (HR 1.11 [95% CI, 0.64-1.94]). Oii-LPD are rare with the most frequent subtype being DLBCL occurring in the setting of methotrexate use. In this population-based analysis, the outcomes of iatrogenic immunodeficiency-associated DLBCL were not significantly different from those of de novo DLBCL patients.