PERIPHERAL-BLOOD LYMPHOCYTE SUBSET DISTRIBUTION AND FUNCTION IN PATIENTS WITH ALZHEIMERS-DISEASE AND OTHER DEMENTIAS

Background: Until recently, new data on immune aspects of Alzheimer's disease (AD) have suggested that some facets of AD pathogenesis may be immune related. However, the effects of dementia itself on immune fun ction have not been considered. Aim: To compare the distribution of pe ripheral blood lymphocyte subsets and their function in patients with AD and other dementias. Methods: Peripheral blood lymphocyte numbers, T cell subset distribution, proliferative responses to mitogens and su ppressor cell assay were studied in a well characterised group of pati ents with AD, and compared to patients with other forms of dementia. A ge and sex matched elderly controls were screened to exclude dementia, and young controls were medical, paramedical and laboratory staff. An alysis of variance (ANOVA) and student's t test were used for statisti cal analysis. Results: The CD8 + lymphocyte population was reduced in AD and in other forms of dementia, when compared with non-demented eld erly and young controls. Concanavalin A induced lymphocyte transformat ion was reduced in all dementia groups and in elderly compared with yo ung controls. The changes in T cell numbers and function were not spec ific for Alzheimer's disease, but were found also in other forms of de mentia.