RESUMEN
BACKGROUND: The effect of radiation on the ileal pouch is less well studied in patients with inflammatory bowel disease (IBD) and ileal pouch-anal anastomosis. AIMS: This retrospective study investigates the impact of external radiation therapy on the outcomes of ileal pouches. METHODS: The study included 82 patients with IBD and ileal pouches, of whom 12 received pelvic radiation, 16 abdominal radiation, 14 radiation in other fields, and 40 served as controls with no radiation. Pouch-related outcomes, including pouch failure, worsening of symptoms, pouchitis, and development of strictures, along with changes in Pouch Disease Activity Index (PDAI) scores pre- and post-radiation were assessed. RESULTS: The pelvic radiation group exhibited a significantly higher rate of pouch failure (25%, p < 0.004) and worsening pouch-related symptoms (75%, p = 0.012) compared to other groups. Although not statistically significant, a higher incidence of pouchitis was observed in the pelvic radiation group (45.5%, p = 0.071). Strictures were more common in the pelvic radiation group (25%, p = 0.043). Logistic regression analysis revealed that pelvic radiation significantly increased the odds of pouch-related adverse outcomes (OR 5.66; 95% confidence interval: 1.61-21.5). CONCLUSION: Pelvic radiation significantly impacts the outcomes of ileal pouches in patients with IBD, increasing the risk of pouch failure, symptom exacerbation, and structural complications. These findings underscore the need for careful consideration of radiation therapy in this patient population and highlight the importance of closely monitoring and managing radiation-induced pouch dysfunction.
RESUMEN
Importance: Factors associated with clinical heterogeneity in Alzheimer disease (AD) lay along a continuum hypothesized to associate with tangle distribution and are relevant for understanding glial activation considerations in therapeutic advancement. Objectives: To examine clinicopathologic and neuroimaging characteristics of disease heterogeneity in AD along a quantitative continuum using the corticolimbic index (CLix) to account for individuality of spatially distributed tangles found at autopsy. Design, Setting, and Participants: This cross-sectional study was a retrospective medical record review performed on the Florida Autopsied Multiethnic (FLAME) cohort accessioned from 1991 to 2020. Data were analyzed from December 2022 to December 2023. Structural magnetic resonance imaging (MRI) and tau positron emission tomography (PET) were evaluated in an independent neuroimaging group. The FLAME cohort includes 2809 autopsied individuals; included in this study were neuropathologically diagnosed AD cases (FLAME-AD). A digital pathology subgroup of FLAME-AD cases was derived for glial activation analyses. Main Outcomes and Measures: Clinicopathologic factors of heterogeneity that inform patient history and neuropathologic evaluation of AD; CLix score (lower, relative cortical predominance/hippocampal sparing vs higher, relative cortical sparing/limbic predominant cases); neuroimaging measures (ie, structural MRI and tau-PET). Results: Of the 2809 autopsied individuals in the FLAME cohort, 1361 neuropathologically diagnosed AD cases were evaluated. A digital pathology subgroup included 60 FLAME-AD cases. The independent neuroimaging group included 93 cases. Among the 1361 FLAME-AD cases, 633 were male (47%; median [range] age at death, 81 [54-96] years) and 728 were female (53%; median [range] age at death, 81 [53-102] years). A younger symptomatic onset (Spearman ρ = 0.39, P < .001) and faster decline on the Mini-Mental State Examination (Spearman ρ = 0.27; P < .001) correlated with a lower CLix score in FLAME-AD series. Cases with a nonamnestic syndrome had lower CLix scores (median [IQR], 13 [9-18]) vs not (median [IQR], 21 [15-27]; P < .001). Hippocampal MRI volume (Spearman ρ = -0.45; P < .001) and flortaucipir tau-PET uptake in posterior cingulate and precuneus cortex (Spearman ρ = -0.74; P < .001) inversely correlated with CLix score. Although AD cases with a CLix score less than 10 had higher cortical tangle count, we found lower percentage of CD68-activated microglia/macrophage burden (median [IQR], 0.46% [0.32%-0.75%]) compared with cases with a CLix score of 10 to 30 (median [IQR], 0.75% [0.51%-0.98%]) and on par with a CLix score of 30 or greater (median [IQR], 0.40% [0.32%-0.57%]; P = .02). Conclusions and Relevance: Findings show that AD heterogeneity exists along a continuum of corticolimbic tangle distribution. Reduced CD68 burden may signify an underappreciated association between tau accumulation and microglia/macrophages activation that should be considered in personalized therapy for immune dysregulation.