👤 Gayathiri Rajkumar

Psychosis in Alzheimer's disease (AD), including hallucinations and delusions, affects up to 50% of patients and is linked to faster cognitive decline. Delusions can occur across AD, with persecutory delusions early and misidentification delusions late, while hallucinations emerge in advanced stages and predict greater cognitive and functional decline. The APOE4 allele is the strongest genetic risk factor for late-onset AD, although its influence on neuropsychiatric symptoms, including psychosis, remains unclear. This study examined the interaction between APOE4 status, sex, EHT use, and psychosis symptoms in AD using data from participants in the National Alzheimer's Coordinating Center Uniform Data Set. Generalized Additive Models assessed nonlinear associations between predictors and psychosis outcomes, including the presence of delusions, hallucinations, and their visual and auditory subtypes. Analyses were stratified by sex (males: n = 13,841, females: n = 15,354). Predictor variables included APOE4 status, current use of estrogen hormone therapy (EHT) in females. Due to limited data availability, CSF biomarkers (Aβ1-42, p-tau181, t-tau) could not be included in the main models and were instead examined in a secondary sub analysis. APOE4 homozygosity was associated with significantly greater odds of delusions in the past month in both males and females, with a stronger effect in females (p<0.05). In females only, APOE4 homozygosity was significantly associated with hallucinations, with no effect in males (p<0.05). EHT was associated with lower risk of hallucinations in females (p<0.05). These findings underscore sex-specific genetic and biological contributors to psychosis in AD and support sex-stratified approaches to understanding and addressing psychosis symptoms in clinical settings. Show less

Systemic light chain amyloidosis (AL) arises from monoclonal immunoglobulin light chains, but determinants of progression from precursor states remain poorly defined. In a cross-sectional cohort comprising 1950 systemic AL patients diagnosed 2010-2024, 258 (13.2%) patients with a previously diagnosed plasma cell disorder (PCD) were compared to patients with no prior PCD diagnosis. Patients with monoclonal gammopathy of undetermined signficance (MGUS) and smoldering multiple myeloma (SMM) in the former group had lower difference between involved and uninvolved FLCs (dFLC), higher M-protein, and lower rates of t(11;14) at AL diagnosis. Patients developing AL from SMM had a shorter time to AL (median 34.2 versus 61.3 months) and higher dFLC (median 28.9 versus 11.0 mg/dl) compared to those from MGUS. Patients developing AL after known multiple myeloma (MM) or lymphoplasmacytic lymphoma (LPL) commonly lacked deep hematologic response before AL (≤ very good partial response in 78% of MM, 100% of LPL patients). We additionally studied longitudinally followed cohorts of 3,966 MGUS and 426 (SMM) patients with longitudinal FLC measurements and matched follow-up, in which 1.8% of MGUS and 7.2% of SMM patients developed AL. Those patients who developed AL showed markedly higher dFLC at MGUS/SMM diagnosis and more frequent λ restriction and rates of t(11;14). Higher dFLC was associated with progressively earlier AL development; a 10% cumulative risk occurred at 20 months for patients with a dFLC >80 mg/dL but was not reached if dFLC <10 mg/dL at an estimated median follow-up of 86 months. In multivariable analysis, dFLC >6.4 mg/dL (HR 11.3) and λ isotype (HR 3.6) independently predicted AL, whereas heavy chain secretion was associated with lower risk (HR 0.2 for IgG). These findings indicate that AL risk is primarily driven by cumulative light chain exposure, refining our knowledge of AL pathophysiology and providing guidance for follow-up of patients with elevated dFLC. Show less