Relationship Between Cerebrospinal Fluid Alzheimer's Disease Biomarker Values Measured via Lumipulse Assays and Conventional ELISA: Single-Center Experience and Systematic Review.

Background: Although Lumipulse assays and conventional ELISA are strongly correlated, the precise relationship between their measured values remains undetermined. Objective: To determine the relationship between Lumipulse and ELISA measurement values. Methods: Patients who underwent cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarker measurements and consented to biobanking between December 2021 and June 2023 were included. The relationship between values measured via Lumipulse assays and conventional ELISA were evaluated by Passing-Bablok analyses for amyloid-ß 1-42 (Aß42), total tau (t-tau), and phospho-tau 181 (p-tau 181). Studies using both assays were systematically searched for in PubMed and summarized after quality assessment. Results: Regression line slopes and intercepts were 1.41 (1.23 to 1.60) and -77.8 (-198.4 to 44.5) for Aß42, 0.94 (0.88 to 1.01) and 98.2 (76.9 to 114.4) for t-tau, and 1.60 (1.43 to 1.75) and -21.1 (-26.9 to -15.6) for p-tau181. Spearman's correlation coefficients were 0.90, 0.95, and 0.95 for Aß42, t-tau, and p-tau181, respectively. We identified 13 other studies that included 2,117 patients in total. Aß42 slope varied among studies, suggesting inter-lab difference of ELISA. The slope and intercept of t-tau were approximately 1 and 0, respectively, suggesting small proportional and systematic differences. Conversely, the p-tau181 slope was significantly higher than 1, distributed between 1.5-2 in most studies, with intercepts significantly lower than 0, suggesting proportional and systematic differences. Conclusions: We characterized different relationship between measurement values for each biomarker, which may be useful for understanding the differences in CSF biomarker measurement values on different platforms and for future global harmonization.

Successful treatment with reduced oral steroid dosage in an 81-year-old woman with statin-induced anti-HMGCR immune-mediated necrotizing myopathy.

An 81-year-old woman presented with statin-induced anti-HMGCR immune-mediated necrotizing myopathy. Treatment was successful without complications with a reduced oral steroid dosage from the current consensus for all ages and backgrounds. This case suggests the importance of early diagnosis and the possibility of steroid dosage adjustment considering the patient's age, disease severity, and comorbidities.

18 F-THK5351 PET Can Evaluate Tumor Extension in Intravascular Large B-Cell Lymphoma : Comparison With 11C-Methionine PET and 18F-FDG PET.

ABSTRACT: A 79-year-old man presenting with gait disturbance and cognitive decline was diagnosed with intravascular large B-cell lymphoma (IVLBCL) by random skin biopsy. Some IVLBCL lesions were identified by PET examinations using 11 C-methionine, 18 F-FDG, and 18 F-THK5351. 11 C-methionine and 18 F-FDG uptake, which likely reflects the presence of the lymphoma cells themselves, increased clearly in the left putamen but weakly in the left deep white matter. 18 F-THK5351 uptake increased in all lesions, likely reflecting perivascular astrogliosis caused by IVLBCL. Hence, 18 F-THK5351 PET can evaluate tumor extension in IVLBCL lesions where 11 C-methionine and 18 F-FDG PET may fail in its visualization.

Marked Cognitive and Activities of Daily Living Improvement by Shunt Embolization in a Very Old Man with Portosystemic Encephalopathy Mimicking Alzheimer Disease: A Case Report.

A 91-year-old man with chronic cognitive impairment underwent shunt embolization for portosystemic encephalopathy (PSE). He experienced intermittent episodes of impaired consciousness and decreased cognitive function and activities of daily living (ADL), for which Alzheimer disease was suspected. On admission, he was in a coma and PSE was diagnosed based on his high ammonia level and the computed tomography findings. After shunt embolization, the patient fully recovered from the impaired consciousness and experienced no recurrence. The patient's Revised Hasegawa Dementia Scale and Mini-Mental State Examination scores improved significantly from 12 and 17 to 30 and 29 points, respectively. The Barthel Index score also improved from 55/100 to 85/100, suggesting a marked improvement in ADL. PSE progresses slowly in very old patients and may mimic the clinical course of Alzheimer disease but without liver enzyme abnormalities. Therefore, it should be distinguished in every dementia case.