Citations

Abstract Genetic studies have significantly advanced our understanding of tauopathies, yet the genetic aetiology of Pick’s disease, a rare 3-Repeat tauopathy, remains unclear. The MAPT p.A152T variant has been identified as a risk factor for Alzheimer’s disease and progressive supranuclear palsy, but its role in Pick’s disease is unknown. In this study, we examined the prevalence of MAPT p.A152T in the largest series of neuropathologically confirmed Pick’s disease cases to date (n = 401). Through genotyping, we identified a single mutation carrier in the Pick’s disease cohort (minor allele frequency = 0.12%). We previously reported MAPT p.A152T at a 0.20% frequency in healthy controls (n = 2456), suggesting that it does not associate with 3-Repeat tauopathy risk. To further investigate the effect of the variant on MAPT transcript expression, we used bulk RNA sequencing in Alzheimer’s disease and progressive supranuclear palsy A152T mutation carriers. We did not detect significant differences in 4-Repeat tau levels, though preliminary trends may indicate more nuanced effects that need to be examined with long-read sequencing in a larger series. Overall, our study suggests that MAPT p.A152T does not increase Pick’s disease risk and may instead be linked to 4-Repeat or mixed tau pathologies, warranting further functional investigation.

Abstract Background Alzheimer’s disease (AD) is clinicopathologically heterogeneous. A proportion of patients living with AD present clinically at a younger onset of cognitive symptoms before 65 years old and/or non-amnestic clinical syndromes. Neuropathologically, corticolimbic distribution of neurofibrillary tangle pathology occurs on a continuum with some cases having greater cortical tau pathology relative to limbic regions and others with relatively restricted accumulation in limbic structures. These patterns of corticolimbic tangle distribution are associated with clinical presentation and age at onset. This study sought to examine protein expression differences across the spectrum of clinicopathologic heterogeneity using the NULISA targeted proteomics platform. Methods A series of thirteen neuropathologically diagnosed AD cases from Mayo Clinic prospectively followed research studies were selected to reflect heterogeneity of clinical syndromes and corticolimbic distribution of tangle pathology. Frozen postmortem brain tissue samples were isolated from inferior parietal cortex and homogenized in RIPA buffer for analysis using Alamar Biosciences’ NULISA CNS disease 120 panel. Applying a conservative detection threshold of 75% level of detection for the novel application of NULISA in human brain, we evaluated levels of 69 of 129 protein targets across samples. We examined associations between age at onset cognitive symptoms and corticolimbic distribution of tangles (CLix) separately with individual protein targets using linear regression analysis. Results AD cases with a younger age at onset had higher measured levels of ubiquitin, while older age was associated with higher levels of total tau, CRH, and NPTX2. Investigations of corticolimbic heterogeneity revealed AD cases with lower CLix score (i.e., cortical predominant distribution of tau) had higher measured p-tau181, p-tau231, ubiquitin, and p62. AD cases with higher CLix (i.e., relative cortical sparing) had higher levels of total tau, CRH, NPTX2, MDH1, and HBA1. Brain-derived total tau consistently showed a stronger association in both models. Conclusion This work demonstrates the utility of postmortem proteomics for investigating biomarkers associated with AD clinicopathologic heterogeneity. We observed proteomic differences in synapse integrity, tau post-translational modification, and ubiquitination associated with age at symptomatic onset and corticolimbic distribution of tangle pathology.

Abstract Background The multicentre ALaCaRT and ACOSOG Z6051 randomized trials were unable to demonstrate non-inferiority of laparoscopic versus open surgery for rectal cancer with respect to a composite pathology metric indicating successful resection. Neither trial was individually powered to detect differences in long-term recurrence or survival. This planned meta-analysis determined long-term oncological outcomes of laparoscopic versus open proctectomy for rectal adenocarcinoma. Methods This prospective meta-analysis included individual patient data from patients with cT1–3 N0–2 M0 rectal adenocarcinoma enrolled in the ALaCaRT and ACOSOG Z6051 trials. Pathologically successful resection was defined as complete or near-complete total mesorectal excision, a clear circumferential resection margin (CRM; > 1 mm), and a clear distal resection margin (> 1 mm). The non-inferiority margin for disease-free survival (DFS) was an absolute difference of 5% at least 3 years after surgery. Results The combined data set included 935 patients (65.6% men, mean age 60.7 years, mean body mass index 26.7 kg/m2) randomized to open (457 patients) or laparoscopic (478 patients) proctectomy. Pathologically successful resection was lower in the laparoscopic than open group (85.1% versus 89.9%, respectively; pooled estimate 4.6% difference; 95% confidence interval (c.i.) −8.6% to −0.5%). The median follow-up was 60.2 (interquartile range 49.9–61.1) months. Three-year DFS was 75.2% (95% c.i. 71.1% to 79.2%) and 76.5% (95% c.i. 72.5% to 80.6%) for the laparoscopic and open groups, respectively (pooled estimate difference −1.5%; 95% c.i. −7.2% to 4.2%). Non-inferiority of laparoscopic surgery was not demonstrated because the lower one-sided 95% c.i. (−6.3% to 100%) crossed −5%. Three-year locoregional recurrence was higher in laparoscopic than open group (5.4% (95% c.i. 3.3% to 7.5%) versus 2.0% (95% c.i. 0.7% to 3.4%), respectively; pooled estimate 3.1% difference (95% c.i. 0.6% to 5.6%)). A clear CRM was the most significant and only pathological predictor of both DFS (P < 0.0001) and overall survival (P < 0.0001). Conclusion Laparoscopic proctectomy led to a lower rate of pathologically successful resection and a higher rate of locoregional recurrence at 3 years. The possibility of subsequent poorer DFS or overall survival rate requires further evaluation, because this analysis was not specifically powered for these endpoints.

BACKGROUND: Aortic enlargement is a powerful predictor of dissection and rupture, yet it is rarely evaluated during routine myocardial perfusion imaging, despite the widespread availability of computed tomography (CT) attenuation correction scans. The aim of this study was to determine whether fully automated, opportunistically derived, artificial intelligence-based aortic measurements from myocardial perfusion imaging CT attenuation correction scans are associated with adverse outcomes in a large multicenter cohort. METHODS: CT attenuation correction scans from patients undergoing positron emission tomography/CT and single-photon emission CT/CT myocardial perfusion imaging across 10 centers were included. A deep learning model automatically segmented the thoracic aorta, and a postprocessing algorithm extracted maximum ascending and descending diameters. The aortic size index was calculated by indexing the diameter to body surface area. RESULTS: A total of 29 339 patients (56% men; median age, 66 years [interquartile range, 58–75 years]) were included. Over a median follow-up of 3.5 years (interquartile range, 1.9–5.0 years), 5083 (17.3%) patients died. Median ascending and descending aortic size index values were 1.8 cm/m 2 (interquartile range, 1.6–2.0) and 1.5 cm/m 2 (interquartile range, 1.4–1.6), respectively, with an increase with age and higher values in females. Elevated aortic size index thresholds (ascending >2.2 cm/m 2 ; descending >1.6 cm/m 2 ) were significantly associated with increased all-cause mortality (ascending: adjusted hazard ratio, 1.16 [95% CI, 1.07–1.26], P <0.001; descending: adjusted hazard ratio, 1.23 [95% CI, 1.14–1.31]; P <0.001). Notably, the prognostic value of an abnormal aortic size index persisted independent of age, sex, and perfusion abnormalities. CONCLUSIONS: Artificial intelligence can unlock previously unused information within routine myocardial perfusion imaging CT attenuation correction scans by rapidly and automatically quantifying aortic size at scale. Opportunistic aortic measurements derived from CT attenuation correction may serve as an adjunctive risk biomarker and could add prognostic value to standard myocardial perfusion imaging without additional imaging or radiation.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system in which environmental factors play an important role in shaping disease risk, activity, and progression. Over the past decade, human and experimental studies have consistently shown alterations in the gut microbiome across the phenotypic spectrum of MS and have linked these changes to immune dysregulation, barrier dysfunction, neuroinflammation, and demyelination. Additionally, emerging evidence indicates that microbial function, particularly metabolite production plays a more direct role in shaping immune responses and associated neuropathology. Evidence from both human studies and experimental autoimmune encephalomyelitis models supports a functional role for microbial metabolites in shaping neuroimmune responses. Bacterially derived metabolites such as short-chain fatty acids, bile acids, polyamines, phytoestrogen metabolites, and tryptophan-derived compounds can influence T-cell differentiation, glial activation, epithelial integrity, and neuroimmune communication. Recent longitudinal studies also show associations between metabolite profiles and disability worsening. Because disease-modifying therapies, diet, and microbiome-directed interventions can reshape microbial metabolism, microbial metabolites may represent promising therapeutic targets in the gut-immune-brain axis. In this Review , we integrate current evidence to propose a mechanistic framework in which microbial metabolites act as central regulators of mucosal and systemic immunity that influence different aspects of MS biology. We discuss how this perspective shifts gut microbiome research from descriptive associations to biological mechanisms that more directly link the gut to immune responses and downstream neuropathology. We then evaluate therapeutic strategies that target microbial metabolism and outline key priorities for longitudinal, multi-omics, and interventional studies that are needed to enable microbiome-informed precision therapies in MS.

Abstract TAR DNA-binding protein 43 (TDP-43) pathology frequently co-occurs with Tau neurofibrillary tangles (NFTs) and amyloid β plaques in Alzheimer’s disease (AD), driving significant clinical heterogeneity. Whether TDP-43 engages autonomous molecular programs or instead amplifies Tau-driven neurodegeneration remains difficult to resolve, largely because these pathologies often co-occur. To separate these overlapping signatures, we generated regionally resolved transcriptomic profiles from cognitively normal controls (Controls), neuropathologically defined cohorts of AD, AD with limbic-predominant age-related TDP-43 encephalopathy (AD/LATE), and frontotemporal lobar degeneration (FTLD-TDP), categorizing them by their distinct TDP-43 subtypes (types α and β for AD/LATE; types A and B for FTLD-TDP). By integrating transcriptomic profiles with quantitative measures of phosphorylated TDP-43 (pTDP-43) and Tau (pTau), we separated pathology-associated signals within mixed disease contexts. We found that TDP-43 is linked to distinct transcriptomic programs in AD/LATE that are largely uncoupled from Tau burden and diverge from those observed in FTLD-TDP. These signatures showed regional specificity, with transcriptomic remodeling occurring in the amygdala across both diseases, whereas frontal cortex alterations were largely restricted to FTLD-TDP. Furthermore, by stratifying cases by TDP-43 morphological subtype, we unmasked specific biological trajectories, from immune activation to unique cellular vulnerabilities, that are not apparent in unstratified cohorts. Together, our findings provide a framework for decoupling mixed proteinopathies and demonstrate that TDP-43 shapes autonomous, subtype-dependent transcriptional landscapes in AD.

Abstract Patients with atypical variants of Alzheimer's disease (AD) often present at a younger age with predominantly non‐amnestic impairments and a more aggressive disease course. Historically, individuals with atypical presentations have not been included in large‐scale clinical trials, which typically focus on late‐onset, sporadic amnestic‐predominant AD. Consequently, treatment options and research efforts specific to atypical AD remain limited. The emergence of amyloid‐targeting therapies that slow disease progression underscores these challenges, as evidence supporting their efficacy in early‐onset amnestic and non‐amnestic AD variants is scarce. This perspective article argues that atypical AD represents an excellent disease model for clinical trials and proposes strategies to address critical gaps in clinical trial design for this population. Key considerations include optimizing participant selection approaches, establishing syndrome‐specific or surrogate biological and clinical endpoints, and fostering advocacy to enhance early and accurate diagnosis, equitable representation, and outcomes for these populations.

A 70-year-old woman with a past medical history of breast cancer is undergoing surveillance. She also had a history of repeated blood transfusions for refractory anemia caused by treated marrow metastatic disease. Laboratory tests showed elevated AST (50 U/L) and ALT (115 U/L). 99m Tc MDP bone scintigraphy revealed intense diffuse splenic uptake. No splenic calcifications or infarcts were found on contrast-enhanced CT. MRI demonstrated signal dropout on in-phase sequences and marked T2 hypointensity of the spleen and liver, without focal splenic lesions, suggesting transfusion-related secondary hemosiderosis. Iron overload should be considered when diffuse splenic uptake is observed on bone scintigraphy.

Background Gastro-oesophageal reflux disease (GORD) occurs in most (∼75%) patients with systemic sclerosis (SSc) and significantly impacts quality of life. Current recommendations lack depth and therefore our aim was to produce practical, consensus-based recommendations for refractory SSc-related GORD. Methods An international, multidisciplinary steering board (SB) was assembled (n=19) consisting of clinicians (rheumatologists, gastroenterologists, gastrointestinal surgeons), an expert methodologist and patient representation. After reviewing the latest definitions of GORD and refractory GORD in the published literature, the SB collectively devised a practical definition of SSc refractory-GORD. Initial recommendations were drafted/agreed on by the SB based on review of the existing guidelines, published literature and expert opinion. Two online voting rounds were conducted to determine whether items should be accepted, with >75% and >60% SB agreement required for first and second rounds, respectively. Results There was a good response/completion rate for the initial (74%) and final (84%) voting rounds. The SB agreed on all 36 draft recommendations. The majority (n=34) were approved in the first round. Recommendations were organised according to the following categories: general approach to management (n=5), assessment (n=6), non-pharmacological (n=2) and pharmacological (n=10) management, endoscopic and surgical treatment (n=3), and special circumstances including refractory GORD and SSc-interstitial lung disease (n=3), myositis and SSc connective tissue disease-overlap (n=3) and perilung transplant (n=4). Conclusion The group of experts has drafted extended and practical recommendations for the management of SSc refractory-GORD. The necessity of a structured approach and a patient assessment is highlighted in order to provide a multidisciplinary approach to the tailored choice of the treatment. Our work also has also identified significant unmet needs and has provided a research agenda to advance the field.

ABSTRACT Background Monoclonal gammopathy of thrombotic significance (MGTS) is a recently described chronic prothrombotic condition characterized by monoclonal anti-PF4 antibodies that are detected above the polyclonal antibody background in patient sera (i.e. present as monoclonal gammopathy of undetermined significance, MGUS). Due to conflicting data in the published literature on antibody clonality in heparin-induced thrombocytopenia (HIT), we evaluated clonality and abundance of anti-PF4 antibodies in HIT, including investigating whether an MGUS, if present in HIT, represents the causative anti-PF4 antibody. Methods Blood samples from 15 patients with HIT were subject to Platelet Factor 4-dependent antigen-based and functional tests. The unmanipulated serum antibody repertoire and isolated anti-PF4 antibodies were subjected to mass spectrometric evaluation. Results Two of the 15 HIT patients had an IgG MGUS. Notably, anti-PF4 antibodies were not synonymous with the MGUS antibody in either of the two patients. Eight of the 15 patients demonstrated monoclonal anti-PF4 antibodies, however, none of the anti-PF4 antibodies were detectable as an MGUS upon evaluation of the entire serum antibody repertoire, reflecting their low abundance. In the seven patients with multiple anti-PF4 antibodies, non-monoclonality was confirmed by analysis of deglycosylated antibody heavy chains. Conclusions Anti-PF4 HIT antibodies are monoclonal in approximately 50% of HIT patients, however, antibody abundance is low such that they are not detectable over the polyclonal IgG background (i.e. are MGUS-negative), differentiating HIT from MGTS. This observation helps explain the transient nature of HIT relative to the persistent prothrombotic state seen in MGTS.