Reed-Sternberg cells express CD161 and lectin-like transcript 1 in Hodgkin lymphoma.

[INTRODUCTION] Hodgkin lymphoma (HL) is a B-cell lymphoma, and it is diagnosed by the presence of Reed-Sternberg (RS) cells surrounded by heavy immune cell infiltration in a tissue biopsy. CD161 (Cluster of differentiation 161) and its ligand Lectin-like transcript 1 (LLT1) have recently emerged as a novel immune-regulatory axis that modulates natural killer (NK) and T cell-mediated function in cancer and inflammatory conditions, but their expression in RS cells and association with HL patients' clinical-pathological features remain poorly defined.

[METHODS] In this study, 60 formalin-fixed paraffin-embedded (FFPE) tissue samples were collected from patients in Northern Jordan. In addition to 60 FFPE samples of positive control from benign reactive lymph node tissues and tonsils. Immunohistochemistry (IHC) was performed to assess the expression levels and patterns (cytoplasmic, membranous, or both) of CD161 and LLT1 in RS cells and then correlated with EBV status and clinical-pathological features such as subtype and disease stages.

[RESULTS] LLT1 expression in RS cells was predominantly cytoplasmic, with occasional dual cytoplasmic and membranous expressions. This is the first study in the literature to detect CD161 expression in RS cells as neoplastic cells at protein level. Statistical analyses showed no significant association between LLT1 or CD161 expression in RS cells and HL subtype, stage or EBV status.

[DISCUSSION] These findings provide the first characterization of LLT1 and CD161 expression in RS cells and suggest their potential use as a target in immunotherapy approaches in HL.