Expression of CD94/NKG2A and killer immunoglobulin-like receptors in NK cells and a subset of extranodal cytotoxic T-cell lymphomas

Thirty-two natural killer (NK) and cytotoxic T-cell lymphomas and 14 noncyt otoxic nodal T-cell lymphoma controls were immunostained with the use of mo noclonal antibodies reactive against NK cell receptor (NKR) molecules (CD94 , NKGPA, p58.2, p58.1, p140, p70, p50.3). All NK-cell lymphomas (4 nasal/or al and 1 intestinal) expressed at least 1 NKR, the CD94/NKG2A complex. Two were positive for 1 or more killer immunoglobulin like receptors. Of 15 ext ranodal cytotoxic T-cell lymphomas, 3 expressed CD94, including 2 intestina l and 1 hepatosplenic gamma delta T-cell lymphomas. In contrast, none of th e nodal lymphomas were positive. Detection of NKRs may provide a useful too l to confirm the diagnosis of NK cell lymphomas and to delineate a subgroup of cytotoxic T-cell lymphomas. Expression of NKRs only in extranodal cytot oxic T-cell lymphomas might reflect differences in the homing capabilities of cytotoxic T cells expressing NKRs in normal individuals end might be inf luenced in part by localized chronic immune reactions. (Blood. 2000;95:3628 -3630) (C) 2000 by The American Society of Hematology.