ENHANCED CYTOTOXIC RESPONSE OF NATURAL-KILLER-CELLS TO INTERLEUKIN-2 IN ALZHEIMERS-DISEASE

Experimental data suggest an involvement of immune cellular components in the development of Alzheimer's disease (AD). Against this backgrou nd, the spontaneous natural killer (NK) cell activity and the NK-induc ed cytotoxicity after interleukin-2 (IL-2) were studied in healthy eld erly subjects and in patients with dementia of Alzheimer type (SDAT) a nd multi-infarct type (MID). Higher NK cytotoxicity (expressed as tota l lysis and percent increase) at different IL-2 concentrations (50 and 100 IU/ml/cells) was demonstrated in patients with SDAT than in healt hy elderly subjects (p < 0.001) and MID patients (p < 0.001). NK cell activity of MID patients was similar to that of healthy elderly and he althy young subjects. A negative correlation between the percent incre ase in NK cytotoxicity after IL-2 and the Mini Mental State Examinatio n Score was also found in SDAT patients (p < 0.01). Alterations of IL2 -mediated NK cytotoxicity may therefore support the neuroimmune hypoth esis of AD.