Objective Immunohistochemically (IHC) measured transactive response DNA‐binding protein 43 (TDP‐43) inclusions are observed in Alzheimer's disease (AD) and are associated with medial temporal lobe atrophy. Accumulation of cryptic exons occurs in AD in response to TDP‐43 pathology. We aimed to assess relationships between IHC and biochemically measured insoluble TDP‐43 and cryptic exons and assess associations with hippocampal and amygdala volume loss and atrophy rates on magnetic resonance imaging (MRI). Methods Eighty‐one neuropathologically diagnosed AD cases were analyzed. For biochemistry, insoluble TDP‐43 was quantified using a Meso‐scale discovery (MSD) immunoassay. IHC‐TDP burden was quantified with digital histopathology. Cryptic RNAs were assessed via quantitative real‐time polymerase chain reaction (qRT‐PCR). Thirty‐eight cases had serial brain MRI. Hippocampal and amygdala volumes were calculated using FreeSurfer. Regression models were used to investigate associations among IHC‐TDP‐43 status/burden, MSD‐TDP status/levels, cryptic RNAs, and hippocampal and amygdala volumes and atrophy rates. Results IHC‐TDP(+) cases exhibited elevated levels of MSD‐TDP and cryptic RNAs ( KCNQ2 , STMN2 , and UNC13A ) and increased MSD‐TDP levels were associated with increased cryptic RNA levels, in the hippocampus and amygdala. IHC‐TDP(+) cases had smaller hippocampal and amygdala volumes compared to IHC‐TDP(−) cases. MSD‐TDP(+) cases had smaller hippocampal volumes and faster amygdala rates of atrophy compared with MSD‐TDP(−) cases. Higher KCNQ2 and UNC13A levels were associated with smaller amygdala volumes. Interpretation MSD‐TDP level is a reliable surrogate for IHC‐based TDP‐43 status. Both TDP‐43 and cryptic RNA levels are associated with reduced medial temporal volumes, suggesting cryptic exons may be playing a role in brain volume loss in AD. ANN NEUROL 2026;100:193–205
Abstract 4661: Expression of the ferroptosis suppressor FSP1 but not GPX4 shows significant adverse prognostic effect in diffuse large B-cell lymphoma with wild-type
TP53
Abstract Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common type of malignant lymphoma. Previous studies have shown that DLBCL cells are susceptible to GPX4 (Glutathione peroxidase 4)-regulated ferroptosis, an iron-dependent type of programmed cell death characterized by increased reactive oxygen species and excessive lipid peroxidation. In addition to GPX4, FSP1 (Ferroptosis suppressor protein 1, previously known as AIFM2) is a glutathione-independent repressor of ferroptosis that has shown prognostic significance in solid tumors. In this study, we aimed to reveal the significance of GPX4 and FSP1 in DLBCL. Patients and Methods: We performed immunohistochemistry (IHC) for GPX4 and FSP1 in a large cohorts of patients with de novo DLBCL, and evaluated their cytoplasmic and nuclear expression. Prognostic analysis was performed for FSP1 and GPX4 expression in patients treated with rituximab (R)-CHOP or CHOP chemotherapy, respective of TP53 mutation status, as p53 regulates ferroptosis and TP53 mutation is associated with poorer prognosis in DLBCL. Results: FSP1 expression with a ≥10% cutoff was positive in 42.3% of DLBCL cases. Patients with TP53 mutations had a non-significant trend of higher mean FSP1 expression than those with wild-type (Wt) TP53 (P=0.11). Prognostic analysis revealed that cytoplasmic FSP1+ expression was associated with significantly poorer overall survival and progression-free survival in Wt-TP53 DLBCLs treated with R-CHOP (P=0.016 and P=0.003, respectively), and only showed non-significant unfavorable trends in TP53 mutated DLBCLs and patients treated with CHOP. In contrast, GPX4 expression did not show a significant unfavorable prognostic effect in DLBCL, and in fact, was associated with a non-significant trend of better survival. Previously we have quantified immune cell abundance and PD-1/PD-L1 expression in the tumor microenvironment of the study cohort using multiplex fluorescent IHC. Correlative analysis found that FSP1+ patients had significantly higher mean and median abundance of CD68+ cells (both M1 and M2 macrophages) and CD11c+ cells than FSP1- patients. Further analysis in Wt-TP53 and mutated TP53 subcohorts found that only in the TP53 mutated DLBCL subcohort, FSP1 expression was associated with significantly higher mean and median CD163-CD68+ (M1) and overall CD68+ macrophages, whereas in the Wt-TP53 DLBCL subcohort, FSP1 expression was associated with significantly higher median (but not mean) CD163+CD68+ (M2) macrophages and CD11c+ cells. Summary: Cytoplasmic FSP1 expression but not GPX4 had significantly adverse prognostic effect in patients with Wt-TP53 DLBCL treated with standard immunochemotherapy. Our results also suggest that in addition to ferroptosis regulation, macrophage abundance was relevant for the prognostic effects of FSP1 expression. Citation Format: Beibei Lyu, Zijun Xu-Monette, Xiaoxian X. Zhao, Eric D. Hsi, Ming Chen, Carlo Visco, Alexandar Tzankov, Karen Dybkaer, Mu-En Wang, Chang Wang, Qingyan Au, Harry Nunns, Zenggang Pan, Benjamin Parsons, Santiago Montes-Moreno, Fenghuang Zhan, Michael B. Møller, Leon Bernal-Mizrachi, Youli Zu, Shanxiang Zhang, Weina Chen, Govind Bhagat, Yong Li, KEN H. YOUNG. Expression of the ferroptosis suppressor FSP1 but not GPX4 shows significant adverse prognostic effect in diffuse large B-cell lymphoma with wild-type TP53 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 4661.
Abstract 215: Primary cardiac lymphoma and HIV: A nationwide analysis of hospitalizations.
Abstract Background: Primary Cardiac Lymphoma (PCL) is an exceptionally rare malignancy. While clinical case reports have postulated an association with human immunodeficiency virus (HIV), large-scale epidemiological data corroborating this link are limited. Objective: To determine whether HIV is associated with increased prevalence of PCL in a large, nationally representative sample of US hospitalizations. Methods: We performed a retrospective, cross-sectional analysis using the Healthcare Cost and Utilization Project National Inpatient Sample from 2016 to 2019, representing approximately 35 million unweighted hospitalizations. Hospitalizations were identified using a proxy definition for PCL, requiring ICD-10-CM codes for both cardiomyopathy (I42.*) and extranodal non-Hodgkin lymphoma (i.e., C83.39, C85.99). HIV status was identified using codes B20-B24 and Z21. We compared the prevalence of PCL in hospitalizations with versus without HIV and calculated odds ratios using Fisher’s Exact Test, reporting corresponding 95% confidence intervals (CI) and p-values. Results: We identified 569 hospitalizations meeting our operational definition for PCL out of 34,955,252 total discharges. The prevalence of PCL was significantly higher among hospitalizations with HIV (6.2 per 100,000) compared with those without HIV (1.6 per 100,000; p < 0.0001). HIV was associated with a 3.86-fold increased odds of PCL (OR: 3.86; 95% CI: 2.23-6.70; p < 0.0001). Conclusion: In this nationwide analysis of 35 million hospitalizations, HIV was strongly associated with a higher prevalence of PCL. Hospitalizations with HIV had nearly 4-fold higher odds of PCL, as defined by co-occurrence of cardiomyopathy and extranodal lymphoma, compared with hospitalizations without HIV. This population-level finding evinces the association previously suggested in clinical case reports. Citation Format: Omar Hozayen, Jay Hozayen, Benjamin Behers, Christoph Stephenson-Moe, Maha Hameed, Matthew Miller, Laura De Jesus Herrera, Anas Abu Jad, Rheiner Kammer, Mohab Idriss, Ahmed Aboutaleb, Bashar Roumia, Patricia Riano, Nicolas Riveros Neira, Brooke Hartenstein, Robert Taylor, Manuel Rosario Espinal, Brett M. Behers, Alya Hozayen, Mohamed Ibrahim, Karen Hamad. Primary cardiac lymphoma and HIV: A nationwide analysis of hospitalizations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 215.
Consensus recommendations for malignant histiocytic neoplasms (histiocytic, Langerhans, and interdigitating dendritic cell sarcomas)
Abstract Malignant histiocytic neoplasms (MHNs) are rare tumors derived from the mononuclear phagocyte system (MPS), encompassing histiocytic sarcoma, Langerhans cell sarcoma, interdigitating dendritic cell sarcoma, and other high-grade MPS lineage tumors. Despite advances in understanding histiocytic neoplasms, MHNs remain diagnostically challenging and lack standardized treatment algorithms. Current classification systems differ in lineage framing and fail to address mixed or ambiguous phenotypes, contributing to diagnostic uncertainty and inconsistent care. To address these gaps, the Histiocyte Society convened an international working group of pathologists and oncologists, including World Health Organization and International Consensus Classification contributors, to harmonize nomenclature, define minimum diagnostic criteria, and develop pragmatic treatment recommendations. Using a modified Delphi process and case-based review, the group formulated >40 consensus statements spanning classification, pathology, molecular testing, clinical evaluation, and therapeutic strategies. Key recommendations include the adoption of a unified MHN designation, use of a minimum immunophenotypic panel, integration of broad molecular profiling, and the documentation of previous hematopoietic malignancy. Treatment algorithms emphasize surgical resection for unifocal disease and targeted therapy or immune checkpoint inhibition for multifocal disease when actionable mutations or programmed death ligand 1 expression are present. These consensus recommendations aim to reduce diagnostic ambiguity, standardize reporting, and improve outcomes for both pediatric and adult patients. Future priorities include international registries to refine risk stratification and biomarker-driven trials exploring targeted therapy, immunotherapy, and combination approaches.
Social Risk Factors and Their Effect on Health Care Costs in a Midwestern Health Care System
Objectives: To assess how social risk factors and socioeconomic status (SES) affect health care costs at a large, integrated health system of 45 clinics in Iowa, Minnesota, and Wisconsin. Methods: We retrospectively reviewed administrative patient cost data from January 1 through December 31, 2022. Social risk factors (lack of financial resources, food insecurity, intimate partner violence, unmet transportation needs, and housing instability) were determined with patient questionnaires. Cost z -scores were compared across all risk-factor quartiles. We used a housing-based measure to objectively determine SES. Results: We analyzed data from 410 624 patients empaneled with 689 family medicine clinicians. Self-reported risk factor data were incomplete for 219 321 patients. Costs were higher for those with higher social risk (mean cost z -score: high risk = 0.38, low risk = 0.11; P < .001). In addition, higher costs were associated with increasing age, greater medical complexity (higher Adjusted Clinical Group scores), White race, and lack of financial resources. Although we observed geographic variations in cost, urban and rural locations did not have significant cost differences. Costs were similar across all quartiles of SES, and the absolute difference in cost z -scores between the highest and lowest SES quartiles was only 0.04. The multivariate analysis, which adjusted for age, medical complexity, race, sex, and objective SES, showed that these specific associations were substantially decreased and no longer significantly associated with mean cost z -scores. Conclusions: Patient-reported social risk factors were significantly associated with increased cost of care in a large, multispecialty health system in the midwestern US. These associations were decreased in the multivariate analysis. Results should be interpreted cautiously for readers outside the midwestern US, given potential responder bias and the racial homogeneity (92% White) of the study cohort.
Stroke and systemic embolism following atrial fibrillation ablation: the EMBOL-AF Global Registry
Abstract Background and Aims Stroke and systemic embolism are recognized but poorly characterized complications of atrial fibrillation (AF) and left atrial flutter (AFL) catheter ablation. Their incidence, outcomes, and procedural associations remain insufficiently defined. Methods Retrospective global registry was initiated by the European Heart Rhythm Association Scientific Committee. A secure database captured data from ablation centres worldwide on general AF and left AFL ablation activity, as well as detailed information on patients with symptomatic embolic events between 2017 and 2024. Results Overall, 204 centres reported 335 743 ablation procedures and 550 embolic events (incidence 0.16%). Centre-level rate ranged from 0% to 3.1%. Most events were cerebral (94%), followed by peripheral (5%), and combined (1%). Coronary air embolism accounted for 62% of all peripheral events. Intraprocedural events occurred in 93 patients (17%), within 72 h in 357 (78%) and beyond 72 h in 100 (22%); 128 cases (23%) were diagnosed after hospital discharge. Nonparoxysmal AF (0.23% vs 0.15%; P < .001), centre experience, and ablation energy source (radiofrequency, 0.16%; cryoballoon, 0.16%; pulsed field ablation, 0.25%; laserballoon, 0.88%; P < .001) were associated with embolic risk. Median NIHSS score after stroke was 4 (interquartile range, 2–9). Three-month follow-up was available for 518 patients with embolism (95%): 181 (35%) had sequelae and 16 (3%) died. Conclusions Symptomatic embolic events are infrequent but associated with significant morbidity and mortality. Most events occur early, though a substantial proportion arise later. Higher event rates were observed with laser and possibly with pulsed field ablation. A greater centre experience was associated with a lower embolism incidence.
Variants in TMEM106B and GRN , which encode lysosomal proteins, interact through unknown mechanisms to increase the risk of age-related cognitive decline and neurodegeneration. Here, we show that these variants converge on a single molecular intermediate: the cleaved intra-lysosomal fibril core of TMEM106B, a precursor to amyloid fibrils that accumulate in the aging brain. A protein-coding TMEM106B risk variant (p.T185) drives fibril core accumulation by impairing its degradation and GRN risk variants amplify this effect. Mice over-expressing the fibril core develop hallmarks of neurodegeneration, and cryo-electron tomography reveals intra-lysosomal fibrils in cultured neurons, mice, and diseased human brain. In GRN -mutation carriers, in whom fibril burden is greatest, fibrils extrude through ruptured lysosomal membranes. These findings identify intra-lysosomal TMEM106B fibrillization as a convergent neurodegeneration mechanism and potential therapeutic target.
1433: LUCAS VS MANUAL CPR IN OBESE IN-HOSPITAL CARDIAC ARREST: SURVIVAL OUTCOME
Abstract Background: High-grade astrocytoma with piloid features (HGAP) is a recently defined tumor type that is not well-understood. Prognostic factors of clinical outcome are not well-established. Methods: Samples were processed at the National Cancer Institute (NCI) Laboratory of Pathology, and published samples were included (n=421). Methylation classifier scores of ≥0.90 to the HGAP class on the NCI-Bethesda classifier were included. Clinical features were collected from the medical record. Kaplan-Meier survival analysis as well as Cox-proportional hazards was performed. Results: The cohort comprised 421 patients. There was a high rate of ATRX alteration (62%), CDKN2A/B loss (78%) and MGMT promoter methylation (53%). MAPK alterations were identified in 74% of samples. The median age was 46 years, and posterior fossa location was predominant (52%). The median overall survival (OS) was 88 months. Older age (p = 0.01) and the presence of an ATRX alteration (p = 0.04) were found to be poorly prognostic. The presence of cystic features on magnetic resonance imaging (MRI) was found to be favorably prognostic (p = 0.01). Factors that were not significantly associated with survival included histologic anaplasia, CDKN2A/B homozygous deletion, MGMT promoter methylation and surgery type. Conclusions: Utilizing a relatively large cohort of HGAP cases, this work establishes relative frequencies of several important markers, and additionally suggests older age, the presence of an ATRX alteration, and cystic features on MRI as prognostic. Our work may aid in identifying treatment regiments for patients with this tumor type. Citation Format: Shuodan Zhang, Omkar Singh, Karen Dazelle, HGAP manuscript co-authors, Kenneth Aldape. High-grade astrocytoma with piloid features: a clinical and genomic analysis of prognostic factors using a large cohort [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Brain Cancer; 2026 Mar 23-25; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2026;86(6_Suppl):Abstract nr A057.
Association of Overactive Bladder With Fall Risk Among US Adults Aged 20−69 Years
ABSTRACT Objective Falls are a leading cause of morbidity and loss of independence in adults. The association between overactive bladder (OAB) and fall risk has not been thoroughly investigated. This study evaluated the association between OAB and fall history in a nationally representative sample of US adults aged 20−69 years. Methods We performed a cross‐sectional analysis of adults aged 20−69 years from the 2021−2023 National Health and Nutrition Examination Survey (NHANES). OAB was classified using a composite symptom severity score that assessed urge urinary incontinence and nocturia. Fall history was assessed by self‐reporting (only in participants aged 20−69 years), where a recent fall was defined as experiencing at least one fall within the past year. Survey multivariable logistic regression was used to estimate adjusted odds ratios (aOR) for the association between fall history and OAB after controlling for sociodemographic and clinical covariates. Results Among 4118 participants, the population‐weighted prevalence of OAB was 19.6% (standard error [SE]: 1.1%), and the prevalence of a recent fall was 28.3% (SE: 1.3%). The prevalence of a recent fall was higher among those with OAB (39.7% [SE: 1.6%] vs. 25.7% [SE: 1.5%]). The prevalence of a recent fall increased progressively with OAB symptom severity (24.3% in those with no symptoms vs. 52.4% in those with severe symptoms). In the fully adjusted model controlling for sociodemographic and clinical covariates, OAB was independently associated with a 42% higher odds of experiencing a recent fall (aOR, 1.42; 95% CI, 1.10 to 1.83; p = 0.01). Conclusion OAB is independently associated with an increased risk of a recent fall in US adults aged 20‐69 years, with a strong positive relationship between OAB severity and fall risk. These findings suggest that screening for OAB may be a useful adjunct to fall risk assessment. Future studies are needed to determine whether OAB management reduces the risk of falls.