Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

Anticholinergic burden in adult and elderly people with intellectual disabilities: Results from an Italian multicenter cross-sectional study.

BACKGROUND:Adults and older people with intellectual disabilities (ID) frequently receive anti-cholinergic drugs in chronic use, but no studies in Italy to date have investigated cumulative anticholinergic exposure and factors associated with high anticholinergic burden in this frail population. AIM:To probe the cumulative exposure to anticholinergics and the demographic, social and clinical factors associated with high exposure. METHODS:The 2012 updated version of the Anticholinergic Burden Score (ACB) was calculated for a multicentre sample of 276 adult and older people over 40 years with ID and associations with factors assessed. RESULTS:Overall, antipsychotics, antiepileptics, anxiolytics, and antidepressants were the most frequent classes contributing to the total ACB score. People living in residential care were more likely exposed to high anticholinergic burden (an ACB score of 3+): both community housing (odds ratio [OR] 4.63, 95%CI 1.08-19.95) and nursing home facility ([OR] 9.99, 95%CI 2.32-43.04). There was also a significant association between an ACB score of 3+ and reporting mental health conditions ([OR] 25.56, 95% CI 8.08-80.89) or a neurological disease ([OR] 4.14, 95%CI 1.32-12.94). Neither demographic characteristics (age and gender) nor other clinical conditions (somatic comorbidity, levels and typology of ID) were associated with higher anticholinergic load. A high burden of anticholinergic was significantly more frequent in laxative users (22.6% ACB3+ vs. 5.1% ACB 0) (p = 0.003). CONCLUSIONS:Psychotropics drugs were the highest contributors to the anticholinergic burden in adult and old age ID, especially in those people living in institutional settings with mental health and/or neurological conditions. High anticholinergic load has shown to be associated with the use of laxatives

A national multicenter study on 1072 DCIS patients treated with breast-conserving surgery and whole breast radiotherapy (COBCG-01 study)

Breast-conserving surgery (BCS) and whole breast radiation (RT) with or without endocrine therapy (ET) represent the standard of care for ductal carcinoma in situ (DCIS). The use of adjuvant treatments after surgery is still controversial in this setting. We performed a retrospective multicenter analysis on a series of DCIS patients treated with BCS and adjuvant RT

Common variants in Alzheimer’s disease and risk stratification by polygenic risk scores

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

New insights into the genetic etiology of Alzheimer’s disease and related dementias

Characterization of the genetic landscape of Alzheimer’s disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/‘proxy’ AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele