Natural killer (Leu 7+) cells in reactive lymphoid tissues and malignant lymphomas.

Leu 7 (HNK-1) is a monoclonal antibody reported to identify human natural killer/killer cells. The frequency and distribution of Leu 7+ cells in 14 reactive lymphoid tissues and 47 malignant lymphomas were studied using the frozen section immunoperoxidase technic. In reactive lymphoid tissues, Leu 7+ cells were concentrated in the pale zone of germinal centers and usually were relatively scarce in the interfollicular areas. Of the malignant lymphomas, follicular lymphomas most consistently had numerous admixed Leu 7+ cells and lymphoblastic lymphomas the least. The authors' findings suggest that Leu 7+ cell accumulation in normal and neoplastic lymphoid tissue is associated at least in part with something shared by the pale zone of the normal germinal centers and the presence of neoplastic germinal centers. This association does not appear to be a simple response to lymphoid proliferation.