engleski

Peripheral biochemical markers in early and late onset Alzheimer’s disease

Alzheimer's disease (AD) is a multifactorial and complex disorder. The age of the onset and the course of AD could be related to the lifestyle, genetic, socidemographic, environmental, clinical and pharmacological factors. Post mortem brain studies indicated that the alterations in neurotransmitters systems could be involved in the ethiology and progress of AD. The aim of the study was to determine peripheral biochemical markers (platelet serotonin/5-HT/ concentration, and the activity of platelet monoamine oxidase type B /MAO/ and plasma dopamine-beta hydroxylase /DBH/) in patients with AD subdivided according to the onset of disease and to the presence of psychotic features. The study included 43 male and 144 female patients with AD subdivided in two groups according to early (before the age of 64 years) or late (after the age of 65 years) onset of AD. The diagnosis of the probable AD fulfilling NINCDS-ADRDA criteria was established according to the ICD-10 and DSM-IV-TR criteria. Mini Mental Status Examination (MMSE) was used to assess the cognitive impairment. The control group consisted of sex and age-matched medication free healthy subjects (65 female and 51 male). Platelet 5-HT concentration and platelet MAO activity were determined using spectrofluorimetric methods, and plasma DBH using photometric method. Platelet 5HT concentration, and plasma DBH activity were decreased, while platelet MAO activity was increased in patients with AD. The highest platelet MAO activity was found in male and female patients with early onset AD. Patients with late onset AD had lower values of plasma DBH activity as compared with patients with early onset AD and healthy controls. The changes in biochemical parameters were not related to the presence of psychotic features. The results of this ongoing study, support the presumption that platelet 5-HT concentration, platelet MAO and plasma DBH activity could be used as the peripheral biological markers for different categories of AD. In addition high platelet MAO B and low plasma DBH activity could be the predictors of the AD. Our results of the altered MAO and DBH activity in patients with AD, support the presumption that toxic and reactive metabolites of catecholamine neurotransmitters could be involved in the ethiology of AD.

Alzheimer's disease; platelet serotonin concentration; platelet monoamine oxidase type B activity; plasma dopamine-beta hydroxylase activity

nije evidentirano