Affiliations: [a] Department of Neuroscience, AFaR - Fatebenefratelli Hospital “San Giovanni Calibita”, Rome, Italy | [b] Laboratory of Neurodegeneration, IRCSS San Raffaele Pisana, Rome, Italy | [c] Department of Neuroimaging, IRCCS San Raffaele Pisana, Rome, Italy | [d] Medical Statistics & Information Technology, AFaR-Fatebenefratelli Hospital “San Giovanni Calibita”, Rome, Italy | [e] Don Carlo Gnocchi Foundation ONLUS, Italy | [f] The Mental Health Research Institute, The University of Melbourne, Victoria, Australia | [g] The Australian e-Health Research Centre, Herston, Queensland, Australia
Correspondence:
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Correspondence to: Rosanna Squitti, PhD, Department of Neuroscience, AFaR - Ospedale Fatebenefratelli, 00186 Rome, Italy. Tel.: +39 06 6837 385; Fax: +39 06 6837 300; E-mail: rosanna.squitti@afar.it.
Abstract: The fraction of copper not bound to ceruloplasmin seems altered in Alzheimer's disease (AD). We have addressed this notion evaluating all the studies carried out from 1996 until March 2013 by means of meta-analysis. We performed our analysis on diverse indices evaluating the relationship between copper and ceruloplasmin in general circulation, namely ‘Non-Cp copper’, ‘% Non-Cp copper’, and ‘Adjusted copper’. For Non-Cp copper and % Non-Cp copper, the correct stoichiometry between copper and ceruloplasmin (6–8 atoms of copper for each ceruloplasmin molecule) in healthy controls has been adopted as criterion for the study to be included in the meta-analysis evaluating data with the canonic Walshe's formula for Non-Cp copper. Copper to ceruloplasmin ratio (Cu:Cp), which is an internal quality control check for ceruloplasmin calibration, was used as an index of the actual stoichiometry in the specimens. Adjusted (Adj-Cp) copper, even though less reliable, was calculated, allowing the evaluation of all the studies selected. An additional meta-analysis of systemic total copper was re-calculated accounting for all the studies carried out from 1983 to March 2013. Ten studies were analyzed in the meta-analysis for Non-Cp copper and % Non-Cp copper reaching a pooled total of 599 AD subjects and 867 controls. For Adj-Cp copper, 14 studies were analyzed with a pooled total of 879 AD and 1,712 controls. 27 studies were considered for systemic total copper meta-analysis, with a pooled total of 1,393 AD and 2,159 controls. All the copper indices analyzed were significantly higher in AD subjects compared to healthy controls.
