Blachy J. Davila Saldana, United States of America
Children's National Medical Center Division of Blood and Marrow TransplantationPresenter of 1 Presentation
CHARACTERIZATION OF CHILDHOOD NK/ T CELL CHRONIC ACTIVE EPSTEIN BARR VIRUS DISORDER (CAEBV)
Abstract
Background and Aims
T/NK-CAEBV is characterized by Epstein-Barr(EBV) infected T and/or NK cells that lead to lymphoproliferation, organ damage, hemophagocytic lymphohistiocytosis (HLH) and/or lymphoma. The best treatment modality is unknown. We sought to characterize a modern cohort of CAEBV patients, focusing on current treatment practices and outcomes.
Methods
Retrospective multi-institutional cohort of patients diagnosed with T/NK CAEBV
Results
Thirty-three patients were evaluated. Median age at diagnosis was 13 (1-30) years, with mean blood EBV DNA 2.2 million copies/mL (range 0-39x106). 70% of patients had cytopenias and liver dysfunction; 45% were clinically diagnosed with HLH. Bortezomib-gancyclovir was upfront therapy in 13 (39%) patients with 61% responders. Twenty-one (64%) patients received lymphoma-type chemotherapy with an 86% overall response. Twenty-nine (88%) patients proceeded to transplant (HCT). With a median 19 months follow up, 1 year overall and event-free survival were 58% and 45%. Fourteen patients died; 71% from progressive disease. No statistically significant improvement in survival was observed with use of chemotherapy (p=0.07) or undetectable viral load pre-HCT (p=0.1), which may be confounded by small sample size. In those undergoing HCT, there was no statistically significant difference in survival between reduced intensity or myeloablative regimens (p=0.73).
Conclusions
NK/T-CAEBV remains extremely challenging to treat. Lymphoma-type chemotherapy results in excellent response rates. HCT remains accepted as the most likely approach to achieve long term remission. With 1 year EFS of <50%, future studies evaluating larger prospective cohorts are required to evaluate whether the use of lymphodepleting chemotherapy to achieve undetectable viral loads prior to HCT improves survival.