Macrophage and polymorphonuclear leukocyte function in patients with Alzheimer disease

Monocyte derived macrophages and polymorphonuclear leukocytes (PMNs) isolated from the peripheral blood of thirteen patients with Alzheimer disease were studied for their cytotoxic effects on a sensitive allogenic tumor target. PMN cells from 11 of the 13 patients with Alzheimer disease were able to kill the tumor cells. In addition, the macrophages from 12 of the 13 Alzheimer disease patients were cytotoxic towards the tumor targets. Four of these patients possessed a plasma inhibitory factor which was capable of suppressing macrophage mediated cytotoxicity. When the lymphocytes from these patients were studied for their ability to be stimulated with the specific antigen, streptokinase, to produce macrophage activating factor (MAF), only 5 of the 13 patients studied possessed lymphocytes which were capable of producing MAF. Thus, the only immunological defect in Alzheimer disease patients which was observed in this study was in the ability of the lymphocytes to synthesize MAF.