Diego. ADNI data are disseminated by the Laboratory for Neuro Imaging at the University of Southern California. We thank Drs. D. Stephen Snyder and Marilyn Miller from NIA who are ex-officio ADGC members. EADI. This work has been developed and supported by the LABEX (laboratory of excellence program investment for the future) DISTALZ grant (Development of Innovative Strategies for a Transdisciplinary approach to ALZheimer's disease) including funding from MEL (Metropole européenne de Lille), ERDF (European Regional Development Fund) and Conseil Régional Rotterdam, Netherlands Organization for the Health Research and Development (ZonMw), the Research Institute for Diseases in the Elderly (RIDE), the Ministry of Education, Culture and Science, the Ministry for Health, Welfare and Sports, the European Commission (DG XII), and the Municipality of Rotterdam. The authors are grateful to the study participants, the staff from the Rotterdam Study and the participating general practitioners and pharmacists. The generation and management of GWAS genotype data for the Rotterdam Study (RS-I, RS-II, RS-III) was executed by the Human Genotyping Facility of the Genetic Laboratory of the

Genetic discoveries of Alzheimer’s disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer’s disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer’s disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer’s disease.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive decline with loss of memory. In the last years there has been a great interest on the early phases of AD, trying to identify the pathogenic mechanisms of AD and define early treatment modalities. In particular, Mild Cognitive Impairment (MCI) is attractive because it represents a transitional state between normal aging and dementia, although not all MCI patients automatically convert to AD. The neurotrophin brain-derived neurotrophic factor (BDNF) is critical for survival and function of neurons that degenerate in AD and represents a potential neuroprotective agent. However, opposite data on serum levels of BDNF have been reported in AD patients, probably reflecting differences in patient recruitment and stage of the disease. Thus, in this study we measured BDNF serum levels in AD patients (with different degree of severity), MCI patients and healthy subjects. We found that serum BNDF levels were significantly increased in MCI and AD patients when compared to healthy subjects and this increase in AD patients was neither dependent on illness severity, nor on treatment with Acetylcholinesterase inhibitors and/or antidepressant medications. Our findings indicate that BDNF serum levels increase in MCI and AD patients, supporting the hypothesis of an upregulation of BDNF in both preclinical phase of dementia (MCI) and clinical stages of AD. Other studies are necessary to establish a direct link between BDNF peripheral levels and AD longitudinal course, as well as the role of other factors, such as blood cell activation, in determining these events.

The progranulin gene (PGRN) encodes a pleiotropic molecule with anti-inflammatory actions and neuronal protective effects. Accordingly, PGRN-deficient mice have been demonstrated to develop enhanced inflammation and progressive neurodegeneration. Loss of function mutations of the PGRN gene have been also reported to cause frontotemporal lobar degeneration (FTLD), a neurodegenerative disease leading to dementia generally in the presenium. Since neurodegeneration might be negatively impacted by chronic inflammation, the possible influence of PGRN defects on inflammatory pathways appears to be of great relevance for the understanding of neurodegeneration pathogenic processes in those patients. However, no data about the inflammatory profile of PGRN-defective subjects have been so far provided.In this study, we analyzed serum levels of the pro-inflammatory mediators IL-6, TNF-α and IL-18 in FTLD patients with or without PGRN mutations, at both pre-symptomatic and symptomatic stages. We provide evidence that circulating IL-6 is increased in PGRN-mutated FTLD patients, as compared to both PGRN non-mutated FTLD patients and controls. In contrast, levels of IL-6 were not altered in asymptomatic subjects carrying the PGRN mutations. Finally, TNF-α and IL-18 serum levels did not differ among all groups of included subjects.We conclude that the profile of circulating pro-inflammatory cytokines is altered in PGRN-related symptomatic FTLD. Thus, our findings point to IL-6 as a possible specific mediator and a potential therapeutic target in this monogenic disease, suggesting that an enhanced inflammatory response might be indeed involved in its progression.