Copper Perturbation in 2 Monozygotic Twins Discordant for Degree of Cognitive Impairment

Background Recent evidence indicates that peripheral tissue markers can provide information regarding changes affecting cellular metabolism in Alzheimer disease (AD). We previously reported that serum copper levels can discriminate subjects with AD from normal control subjects (with 60% sensitivity and 95% specificity) and from patients with vascular dementia (with 63% sensitivity and 85% specificity). Objective To study the correlation between AD and serum levels of transition metals and markers of peripheral oxidative stress. Design Case study. Setting General hospital inpatient wards and outpatient clinics. Patients A pair of elderly monozygotic female twins discordant for AD. Main Outcome Measures Biochemical analyses of peripheral-blood transition metals and indicators of oxidative stress and neurologic and neuropsychological assessments of clinical status for presence of cognitive impairment and AD. Results Serum copper and total peroxide levels were both 44% higher in the twin with greater cognitive impairment and a diagnosis of AD. Conclusions The cases reported support the hypothesis of a major involvement of copper and oxidative abnormalities in AD.