BINDING OF PLATELET-ACTIVATING-FACTOR TO PLATELETS OF ALZHEIMERS-DISEASE AND MULTIINFARCT DEMENTIA PATIENTS

The binding of 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (platele t-activating factor, PAF) to platelets was studied in 22 patients with probable Alzheimer's disease (AD), 11 with multi-infarct dementia (MI D), 22 age-matched normal old controls, and 20 young subjects. The res ults showed a significantly lower degree of PAF binding to platelets o f AD and MID patients than in those of the old controls and young subj ects (133.3 +/- 8.5, and 123.4 +/- 16.5 vs. 202.3 +/- 11.6 and 206.7 /- 17.3 receptors/cell, respectively; p < 0.01). These differences wer e due to reduced B-max, while K-d remained unchanged. No significant d ifference was observed between the PAF binding to platelets of AD and MLD patients nor between that of old and young controls. No correlatio n was found between age and binding in the various elderly groups. How ever, a significant correlation was found between PAF binding and degr ee of cognitive impairment in the AD patients. This is the first evide nce to support a possible involvement of PAF in dementing disorders. C opyright (C) 1996 Elsevier Science Inc.