Rosanna Squitti

Elevation of serum copper levels in Alzheimer’s disease

Objective To determine whether serum trace metals and oxidative species are related to abnormal cognition in AD. Methods The authors studied serum peroxides, copper, iron, transferrin, and antioxidant capacity in 79 patients with AD (mean age 74.3 years; 25 men, 54 women) and in 76 cognitively normal individuals (mean age 70.1 years; 33 men, 43 women). The relation of these oxidative and trace metals to APOE &egr;4 allele frequency, neuropsychological performance, and cerebrovascular or atrophic burden, as estimated by brain MRI and ultrasonography of cerebral vessels, was evaluated. Results Copper level was higher (p < 0.001) in subjects with AD than control subjects (specificity = 95%, sensitivity = 60%) with a cutoff serum level of 16 &mgr;mol/L (1.02 mg/L). An increase of 1 &mgr;mol/L in serum copper accounted for 80% of the risk of having AD and correlated with poor neuropsychological performance and medial temporal lobe atrophy (p < 0.03). Antioxidant capacity decreased and correlated with medial temporal lobe atrophy (p < 0.009) and with APOE &egr;4 allele (p = 0.004). Conclusions Copper may play a role in neurodegenerative processes in AD, and serum copper measurement may prove to be a peripheral diagnostic marker for AD.

Excess of serum copper not related to ceruloplasmin in Alzheimer disease

Objective: To assess the role of serum copper in relation to ceruloplasmin and other peripheral markers of inflammation in Alzheimer disease (AD). Methods: The authors studied serum levels of copper, ceruloplasmin, and transferrin, as well as total peroxides, antioxidants, and other peripheral markers of inflammation in 47 patients with AD, 24 patients with vascular dementia (VaD), and 44 healthy controls. Biochemical variables were related to the patients’ and controls’ clinical status. Results: The authors found that copper (p < 0.001), peroxides (p = 0.026), and ceruloplasmin (p = 0.052) were increased and TRAP was decreased (p = 0.006) in patients with AD, while no other markers of inflammation were altered. The calculation of the ratio between copper and ceruloplasmin suggested the presence in the serum of AD patients, but not of VaD or normal controls, of a large pool of non-ceruloplasmin-bound copper. Conclusions: Changes in the distribution of the serum copper components, consisting of an increase of a copper fraction not explained by ceruloplasmin, seem to be characteristic of Alzheimer disease and may be implicated in the pathogenesis of the disease.

Dietary and lifestyle guidelines for the prevention of Alzheimer's disease.

Risk of developing Alzheimers disease is increased by older age, genetic factors, and several medical risk factors. Studies have also suggested that dietary and lifestyle factors may influence risk, raising the possibility that preventive strategies may be effective. This body of research is incomplete. However, because the most scientifically supported lifestyle factors for Alzheimers disease are known factors for cardiovascular diseases and diabetes, it is reasonable to provide preliminary guidance to help individuals who wish to reduce their risk. At the International Conference on Nutrition and the Brain, Washington, DC, July 19-20, 2013, speakers were asked to comment on possible guidelines for Alzheimers disease prevention, with an aim of developing a set of practical, albeit preliminary, steps to be recommended to members of the public. From this discussion, 7 guidelines emerged related to healthful diet and exercise habits.

Longitudinal prognostic value of serum “free” copper in patients with Alzheimer disease

Background: Serum copper not bound to ceruloplasmin (“free”) appears slightly elevated in patients with Alzheimer disease (AD). We explored whether a deregulation of the free copper pool can predict AD clinical worsening. Methods: We assessed levels of copper, iron, zinc, transferrin, ceruloplasmin, peroxides, total antioxidant capacity, free copper, and apolipoprotein E genotype in 81 patients with mild or moderate AD, mean age 74.4, SD = 7.4 years, clinically followed up after 1 year. The association among biologic variables under study and Mini-Mental State Examination (MMSE) (primary outcome), activities of daily living (ADL), and instrumental activities of daily living (IADL) (secondary outcomes) performed at study entry and after 1 year were analyzed by multiple regression. Results: Free copper predicted the annual change in MMSE, adjusted for the baseline MMSE by means of a linear regression model: it raised the explained variance from 2.4% (with only sex, age, and education) to 8.5% (p = 0.026). When the annual change in MMSE was divided into <3 or ≥3 points, free copper was the only predictor of a more severe decline (predicted probability of MMSE worsening 23%: odds ratio = 1.23; 95% confidence interval = 1.03–1.47; p = 0.022). Hyperlipidemic patients with higher levels of free copper seemed more prone to worse cognitive impairment. Free copper at baseline correlated with the ADL and IADL clinical scales scores at 1 year. Conclusions: These results show an association between copper deregulation and unfavorable evolution of cognitive function in Alzheimer disease. Further research is needed to establish whether copper is an independent risk factor for cognitive decline.

‘Free’ copper in serum of Alzheimer’s disease patients correlates with markers of liver function

SummaryNon-ceruloplasmin bound copper (‘free’) seems slightly elevated in Alzheimer’s disease (AD) patients. To test the hypothesis of a correlation between ‘free’ copper and liver function in AD. We evaluated 51 AD patients and 53 controls through typical tests for chronic liver disease (AST, ALT, γ-GT, Albumin, prothrombin time – PT-, bilirubins), along with copper, ceruloplasmin, iron, cholesterol in the serum and apolipoprotein E epsilon4 (APOE4) genotype. Absolute serum copper and ‘free’ copper were higher, albumin was lower and PT longer in AD patients than in controls. ‘Free’ copper correlated negatively with markers of liver function, in that albumin and albumin/PT ratio (r = −0.43, p = 0.004), and positively with direct bilirubin. Copper and ‘free’ copper were higher in the APOE4 carriers. These results suggest that abnormalities in copper metabolism might have an effect on liver function in AD.

Genotype (cystatin C) and EEG phenotype in Alzheimer disease and mild cognitive impairment: a multicentric study.

Previous findings demonstrated that haplotype B of CST3, the gene coding for cystatin C, is a recessive risk factor for late-onset Alzheimers disease (AD; Finckh, U., von der Kammer, H., Velden, J., Michel, T., Andresen, B., Deng, A., Zhang, J., Muller-Thomsen, T., Zuchowski, K., Menzer, G., Mann, U., Papassotiropoulos, A., Heun, R., Zurdel, J., Holst, F., Benussi, L., Stoppe, G., Reiss, J., Miserez, A.R., Staehelin, H.B., Rebeck, G.W., Hyman, B.T., Binetti, G., Hock, C., Growdon, J.H., Nitsch, R.M., 2000. Genetic association of the cystatin C gene with late-onset Alzheimer disease. Arch. Neurol. 57, 1579-1583). In the present multicentric electroencephalographic (EEG) study, we analyzed the effects of CST3 haplotypes on resting cortical rhythmicity in subjects with AD and mild cognitive impairment (MCI) with the hypothesis that sources of resting EEG rhythms are more impaired in carriers of the CST3 B haplotype than non-carriers. We enrolled a population of 84 MCI subjects (42% with the B haplotype) and 65 AD patients (40% with the B haplotype). Resting eyes-closed EEG data were recorded in all subjects. EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), and beta 2 (20-30 Hz). EEG cortical sources were estimated by low-resolution brain electromagnetic tomography (LORETA). Results showed that the amplitude of alpha 1 (parietal, occipital, temporal areas) and alpha 2 (occipital area) was statistically lower in CST3 B carriers than non-carriers (P < 0.01). Whereas there was a trend towards statistical significance that amplitude of occipital delta sources was stronger in CST3 B carriers than in non-carriers. This was true for both MCI and AD subjects. The present findings represent the first demonstration of relationships between the AD genetic risk factor CST3 B and global neurophysiological phenotype (i.e., cortical delta and alpha rhythmicity) in MCI and AD subjects, prompting future genotype-EEG phenotype studies for the early prediction of AD conversion in individual MCI subjects.

Ceruloplasmin/Transferrin System Is Related to Clinical Status in Acute Stroke

Background and Purpose— In acute stroke, Iron (Fe) may amplify reperfusion injury by catalyzing the conversion of superoxide and hydrogen peroxide into highly reactive radicals. Transferrin (Tf) is the main protein regulating Fe homeostasis, whereas Ceruplasmin (CP) is a circulating ferroxidase enzyme able to oxidize ferrous ions to less toxic ferric forms. This study aims at investigating whether CP, Copper (Cu), Tf, and Fe play a role in the pathophysiology of acute stroke. Methods— We enrolled 35 acute stroke patients and 44 controls. All patients underwent: neurological examination assessed by National Institutes of Health Stroke Scale (NIHSS), ultrasound evaluation of carotid atherosclerosis, brain MRI to quantify ischemic lesion volume and measurement of serum levels of CP, Cu, Tf, Fe, hydro-peroxides, and Total plasmatic antioxidant capacity. Results— In patients, NIHSS scores were associated with Tf (r=−0.48, P=0.004), hydro-peroxides (r=0.34, P=0.046), CP (r=0.43, P=0.012), and lesion volume (r=0.50, P=0.004). Lesion volume was inversely associated with Tf (r=−0.44, P=0.012). CP and hydro-peroxides were also largely related (r=0.81, P<0.001). The model multiple R was 0.57, resulting in a 32.5% of explained NIHSS variance with Tf accounting for 23.4% and CP for 9.1%. Conclusions— CP and Tf levels are representative of clinical status in acute stroke patients. Our findings suggest a protective role of Tf in acute stroke and a possible ambivalent role of CP.

Features of ceruloplasmin in the cerebrospinal fluid of Alzheimer’s disease patients

The level of the apo-form of the copper enzyme ceruloplasmin (CP) is an established peripheral marker in diseases associated with copper imbalance. In view of the proposal that disturbances of copper homeostasis may contribute to neurodegeneration associated with Alzheimer’s disease (AD), the present work investigates, by Western blot and non-reducing SDS-PAGE followed by activity staining, the features of CP protein, and the copper/CP relationship in cerebrospinal fluid (CSF) and serum of AD patients. Results show that only a fraction of total copper is associated with CP in the CSF, at variance with serum, both in affected and in healthy individuals. Furthermore, a conspicuous amount of apo-ceruloplasmin and a decrease of CP oxidase activity characterize the CSF of the affected individuals, and confirm that an impairment of copper metabolism occurs in their central nervous system. In the CSF of AD patients the decrease of active CP, associated with the increase in the pool of copper not sequestered by this protein, may play a role in the neurodegenerative process.

Value of Serum Nonceruloplasmin Copper for Prediction of Mild Cognitive Impairment Conversion to Alzheimer Disease

Meta‐analyses show that nonbound ceruloplasmin (non‐Cp) copper (also known as free or labile copper) in serum is higher in patients with Alzheimer disease (AD). It differentiates subjects with mild cognitive impairment (MCI) from healthy controls. However, a longitudinal study on an MCI cohort has not yet been performed to assess the accuracy of non‐Cp copper for the prediction of conversion from MCI to AD during a long‐term follow‐up.

Is cognitive function linked to serum free copper levels? A cohort study in a normal population.

OBJECTIVE Much research on copper-dependent neurodegeneration has focused on the study of total copper levels in the organism. However, recent evidence suggests that the portion of copper that does not bind to ceruloplasmin and is loosely transported by micronutrients (free copper) may play a more significant role than copper as a whole. In this paper, we measured markers of copper metabolism in the sera of a group of cognitively normal women to test whether abnormal amounts of free copper have detectable effects on the mental state of clinically normal people. METHODS We measured serum levels of free and ceruloplasmin-bound copper in 64 women whose normal mental state had been assessed via a battery of neuropsychological tests representing the major cognitive domains. RESULTS Results show a significant inverse correlation of the serum levels of free copper with both Mini-Mental State Examination (MMSE) and attention-related neuropsychological tests scores. Bound copper, instead, did not correlate with either MMSE scores or any cognitive domain. CONCLUSIONS Free copper appears to be a player in cognitive decline. SIGNIFICANCE This evidence suggests the need for a shift of focus from total to free copper levels in the study of mental decline and sustains the notion that free copper may be a risk factor in the development of impaired cognition.