Expression of natural killer cell markers in non-Hodgkin's lymphomas.

One hundred forty-nine cases of non-Hodgkin's lymphoma were studied with a panel of monoclonal antibodies, including antibodies to natural killer (NK) cells--anti-NKH1, anti-Leu 7, and anti-Leu 11b. There were 95 B-cell, 51 T-cell, and three null cell lymphomas. Seventeen T-cell lymphomas (33 per cent) expressed NKH1, Leu 7, and/or Leu 11b. None of the B- or null cell lymphomas expressed the NK markers. In comparison with the NK-negative T-cell lymphomas, the NK-positive cases showed a predilection for the nasal and paranasal region. There was a more significant loss of the T-cell markers T3 (peripheral T cell) and T4 (T-helper cell) in NK-positive lymphomas. The difference was due to a high proportion of nasal/paranasal lymphomas, which were associated with a frequent loss of T-cell markers, among the NK-positive cases. However, a similar degree of loss of T-cell markers was observed among NK-positive and NK-negative nasal/paranasal lymphomas. We conclude that expression of NK markers occurs exclusively in a proportion of T-cell lymphomas, but not B-cell or null cell lymphomas. The reason this occurs predominantly in nasal and paranasal lymphomas is unknown.