EBV-positive and EBV-negative posttransplant lymphoproliferative disorders (PTLDs) arise in different immunovirological contexts and might have distinct pathophysiologies. To examine this hypothesis, we conducted a multicentric prospective study with 56 EBV-positive and 39 EBV-negative PTLD patients of the K-VIROGREF cohort, recruited at PTLD diagnosis and before treatment (2013–2019), and compared them to PTLD-free Transplant Controls (TC,
n = 21). We measured absolute lymphocyte counts (
n = 108), analyzed NK- and T cell phenotypes (
n = 49 and 94), and performed EBV-specific functional assays (
n = 16 and 42) by multiparameter flow cytometry and ELISpot-IFNγ assays (
n = 50). EBV-negative PTLD patients, NK cells overexpressed Tim-3; the 2-year progression-free survival (PFS) was poorer in patients with a CD4 lymphopenia (CD4
+<300 cells/mm
3,
p < .001). EBV-positive PTLD patients presented a profound NK-cell lymphopenia (median = 60 cells/mm
3) and a high proportion of NK cells expressing PD-1 (vs. TC,
p = .029) and apoptosis markers (vs. TC,
p < .001). EBV-specific T cells of EBV-positive PTLD patients circulated in low proportions, showed immune exhaustion (
p = .013 vs. TC) and poorly recognized the N-terminal portion of EBNA-3A viral protein. Altogether, this broad comparison of EBV-positive and EBV-negative PTLDs highlight distinct patterns of immunopathological mechanisms between these two diseases and provide new clues for immunotherapeutic strategies and PTLD prognosis.
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