Regulation of natural killer cell function by glass-adherent cells in patients with primary intracranial malignancies

Natural killer (NK) cell function against the NK cell-sensitive myeloid leukemia cell line, K562, was measured in the peripheral blood mononuclear cells (PBMCs) of 17 patients with primary brain tumors (4 diagnosed as having low grade tumors and 13 diagnosed as having high grade (malignant) tumors). The ability of monocytes to control the levels of NK cell function in PBMCs from these patients was assessed in glass-adherent cell depletion studies. Most patient assessments were performed before surgical biopsy and diagnosis; most but not all patients were receiving dexamethasone at the time of immunity assessment. The results demonstrate that patients with primary malignant brain tumors have depressed levels of NK cell function in their PBMCs due to the suppressive actions of glass-adherent monocytes, whereas patients with low grade tumors have normal levels of function shown by this assay.