A monoclonal antibody recognizing a natural killer (NK) cell-associated antigen was used to sequentially quantify numbers of peripheral blood NK cells in a small group of patients with large cell lymphoma.
Patients with active disease had low numbers (<100/mm3) of NK cells. Patients in complete remission after therapy had normal numbers of NK cells, but those patients who relapsed had a fall of NK cell number to <100/mm3 preceding or concurrent with clinical relapse. A role for NK cells in the surveillance and control of abnormal lymphoproliferation is suggested, as is the possible prognostic utility of sequential peripheral blood NK cell quantification in patients with large cell lymphoma.
Cancer 57:2309-2312, 1986.
HEMOTHERAPEUTIC cytoreduction OCCUrS eXperi-C mentally by first order kinetics.' By this admittedly simplistic model, complete eradication of tumor by chemotherapy alone is theoretically impossible, since a constant percentage, rather than a constant number, of sensitive tumor cells will be killed regardless of initial tumor size.' In spite of this, chemotherapeutic cure is possible in some advanced malignancies,2 and thus some mechanism must exist in vivo for the control or eradication of microscopic residual tumor. Such a role has been proposed for "natural killer" (NK) lymphocytes, based on the spontaneous cytotoxicity of these cells for a variety of cultured neoplastic target cell^.^.^ It has been demonstrated
that patients with active malignant lymphoma have depressed NK activity as assessed by an in vitro assay of cytotoxicity by peripheral blood mononuclear cells using a cultured target cell line.4 Recently, monoclonal antibodies have been developed allowing the recognition of NK cell-associated antigens.' We have sequentially quantified circulating NK cells in a small group of patients with large cell lymphoma in remission. A correlation was found between circulating NK cell number and clinical course.