Acetyl Cholinesterase Inhibitors and Cell-Derived Peripheral Inflammatory Cytokines in Early Stages of Alzheimer's Disease Nikolaos Kokras, PhD,*† Evangelia Stamouli, PhD,*‡ Ioannis Sotiropoulos, PhD,§† Everina A. Katirtzoglou, MD,* Kostas T. Siarkos, MD,* Georgia Dalagiorgou, PhD,§ Krystallenia I. Alexandraki, PhD,‡|| Stavroula Coulocheri, PhD,‡ Christina Piperi, PhD,‡ and Antonios M. Politis, PhD* Abstract: Background: Clinical and preclinical studies firmly support the involve- ment of the inflammation in the pathogenesis of Alzheimer’s disease (AD). Despite acetylcholinesterase inhibitors (AChEI) being widely used in AD patients, there is no conclusive evidence about their impact on the inflammatory response. Methods: This study investigates peripheral proinflammatory cytokines (interferon gamma [IFN-γ], tumor necrosis factor alpha [TNF-α], and in- terleukins 1β [IL-1β] and 6 [IL-6]) by firstly comparing peripheral blood mononuclear cell (PBMC)–derived secretion in drug-naïve and AChEI- treated AD patients versus healthy controls. A subset of those drug-naïve AD patients, who were prescribed the AChEI donepezil, was followed-up for 6 months to investigate if donepezil suppresses proinflammatory cell- derived cytokine secretion. Results: Patients with AD showed higher levels of PBMC-derived proin- flammatory cytokines (IFN-γ, TNF-α, IL-1β, and IL-6) in comparison with healthy controls. On reexamination, previously drug-naïve AD patients who received donepezil treatment for 6 months displayed a decrease in cell-derived IFN-γ, TNF-α, IL-1β, and IL-6. Conclusions: Proinflammatory PBMC-derived cytokines were increased in patients with AD in comparison with healthy controls and donepezil- reduced proinflammatory cytokines when examining drug-naïve AD patients before and after AChEI treatment. Key Words: Alzheimer’s disease, inflammation, anticholinesterase inhibitors, cytokines, donepezil (J Clin Psychopharmacol 2018;38: 00–00) A lzheimer's disease (AD), the most common type of dementia, is a progressive age-related neurodegenerative disorder clini- cally characterized by a gradual and progressive impairment in cognitive functions. Despite considerable progress in understand- ing the pathophysiology of the disease, 1,2 AD remains a complex, multifactorial disorder with environmental, biological, and genetic risk factors. 3 Interestingly, there is increasing evidence about the involvement of immune system abnormalities in AD pathology. 4 Alzheimer's disease clinical and experimental studies suggest that cytokines-driven inflammatory pathways may trigger AD pathology and highlight their pathogenic role, as intense expression of these factors is found around Aβ deposition areas and neurofibrillary tangles. 5,6 Moreover, altered peripheral levels of interleukins 1β (IL-1β), tumor necrosis factor alpha (TNF-α), and interleukin (IL-6) are reported in patients with AD and higher blood serum IL-1β levels associate with a more rapid cognitive decline. 7,8 Although measurements in peripheral inflammatory markers may only represent a partial reflection of brain pathology, peripheral cytokine levels correlate well with brain inflammation and their detection might be of use for disease assessment. 9,10 Whereas ev- idence firmly supports the involvement of inflammation in the path- ogenesis of AD, there is still no conclusive evidence as to whether acetylcholinesterase inhibitors (AChEI) can have an impact on the in- flammatory response. The AChEI are consistently used in AD pa- tients as symptomatic therapy, mostly helping with cognitive and global outcome measures in a time-limited fashion. 5 While experimental data suggest an AChEI anti-inflammatory effect on suppressing lymphocyte proliferation and proinflammatory cytokine production, 11–13 a recent clinical study failed to identify any differences in IL1b, IL6, and TNFa after AChEI treatment. 14 In this context, the present study investigated cell-derived proin- flammatory cytokines by firstly comparing AChEI-treated and drug-naïve AD patients with healthy controls. We then prospec- tively followed-up a subset of those drug-naïve AD patients who were prescribed the AChEI donepezil to investigate the hypothesis that such treatment would suppress cell-derived proinflammatory cytokine secretion. METHODS Patients The present clinical sample is part of a larger effort on inves- tigating genetic associations in AD, and further details of the pa- tients’ characteristics have been reported previously. 15–17 For this study, 105 consecutive outpatients attending a psychogeriatric outpatient service at the Department of Psychiatry in Medical School of University of Athens were recruited. Informed consent was obtained from all patients, and the study was approved by the University of Athens Medical School Ethics Committee. Of them, 61 patients aged 75.9 (SD, 7.6) years with an average AD illness duration of 2.5 (SD, 2.0) years were not receiving AChEIs at the beginning of the study. Forty-four patients aged 73.9 (SD, 7.2) years and with an average illness duration of 4.0 (2.4) years were already under treatment with AChEIs. After informed consent, all patients were examined with the Structured Clinical Interview for the Diagnostic and Statistical Manual version IV Axis I Disorders (SCID). Thereafter, patients underwent a screening evaluation to determine if they met the following inclusion criteria: diag- nosis of probable AD by National Institute of Neurological and From the *First Department of Psychiatry, Eginitio Hospital, †Department of Pharmacology, and ‡Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, Greece; §Life and Health Sciences Research Institute (ICVS), Medical School, University of Minho, & ICVS/3B’s—PT Government Associate Laboratory, Braga, Portugal; and ||Department of Pathophysiology, Medical School, National and Kapodistrian University of Athens, Greece. Received March 30, 2017; accepted after revision December 19, 2017. Reprints: Nikolaos Kokras, PhD, Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Greece, 75 Mikras Asias St, 11527 Athens, Greece (e‐mail: nkokras@med.uoa.gr). N.K. and E.S. have equal contributions. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0271-0749 DOI: 10.1097/JCP.0000000000000840 BRIEF REPORT Journal of Clinical Psychopharmacology • Volume 38, Number 2, April 2018 www.psychopharmacology.com 1 Copyright © 2018 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.