Homocysteine erythrocyte production in patients affected by dementia

Background: Patients affected by dementia Alzheimer type (DAT) or vascular dementia (VD) often exhibit mild hyperhomocysteinemia (HHcy); HHcy may be important in neuron damage: it is an early marker of vitamin deficit, (folate and vit. B12), often associated with cognitive decline; HHcy itself seems to exert a neurotoxic effect (activation of NMDA receptors and induction of cell death; excitotoxic effect by some metabolites) and it is also an indipendent risk factor for (cerebro)vascular disease. Red blood cells (RBC) have enzymatic activities for Hcy synthesis (methionine demethylation) and (probably) metabolism (remethylation to methionine), representing a possible model for studying abnormalities of Hcy metabolism.Aim: to assess the possible difference in RBC production between healthy elderly and elderly affected by Dementia syndrome.Methods: In 105 subjects affected by dementia (DSM-IV criteria) [55 by DAT (30 f, mean age 78\ub18 years) and 50 by VD (38 f, 81\ub15 years); DAT and VD diagnosis was made by NINCDS-ARDRA and NINDS-AIREN criteria and Hachinsky score] and 40 healthyelderly (controls; 22 f; mean aged 77\ub110 years) we assessed fasting plasma Hcy (HPLC) and serum vit. B12 and RBC folates (RIA) . A RBC sample from all subjects was incubated at 37\ub0 for 8 h in RPMI vitamin-free (Ht=26%) medium. In these samples we measured at time 0 e after 4 and 8 hour Hcy concentration (supernatant and RBC cytoplasm).Results: RBC from AD patients produce more Hcy (p