Philothermal response of polymorphonuclear leukocytes in dementia of the Alzheimer type.

The philothermal response, i.e., the tendency of polymorphonuclear leukocytes (PMNs) to migrate along a temperature gradient toward warmer temperatures, was evaluated in 11 patients with a clinical diagnosis of dementia of the Alzheimer type (DAT) and compared to 11 age and sex-matched mentally normal individuals. While the total number of migrating PMNs did not differ significantly between these two groups, there was a significant difference in the spatial distribution of the responding cell population. The numerical parameter, R, has been introduced to provide a quantitative measure of the distribution of populations characterized by differences in motile behavior. This R value was unusually high for 10 of the DAT patients but only one of the comparison individuals. No relation between R and duration of illness, age, or sex was detected. These preliminary findings, based on a small number of clinically diagnosed DAT patients, suggest that the philothermal response may represent a biological marker with diagnostic usefulness for at least one subgroup of DAT patients.