Second-generation Elecsys cerebrospinal fluid immunoassays aid diagnosis of early Alzheimer's disease.

Objectives: Timely diagnosis of Alzheimer's disease (AD) is critical for appropriate treatment/patient management. Cerebrospinal fluid (CSF) biomarker analysis is often used to aid diagnosis. We assessed analytical performance of second-generation (Gen II) Elecsys CSF immunoassays (Roche Diagnostics International Ltd), and adjusted existing cut-offs, to evaluate their potential utility in clinical routine.

The Alzheimer's Association international guidelines for handling of cerebrospinal fluid for routine clinical measurements of amyloid β and tau.

The core cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarkers amyloid beta (Aβ42 and Aβ40), total tau, and phosphorylated tau, have been extensively clinically validated, with very high diagnostic performance for AD, including the early phases of the disease. However, between-center differences in pre-analytical procedures may contribute to variability in measurements across laboratories. To resolve this issue, a workgroup was led by the Alzheimer's Association with experts from both academia and industry.

Pre-analytical protocol for measuring Alzheimer's disease biomarkers in fresh CSF.

Introduction: We aimed to establish a standardized, routine-use pre-analytical protocol for measuring Alzheimer's disease (AD) biomarkers in cerebrospinal fluid (CSF).

Methods: The effect of pre-analytical factors (sample collection/handling/storage/transportation) on biomarker levels was assessed using freshly collected CSF. Tube type/sterilization was assessed using previously frozen samples.

Method comparison study of the Elecsys® β-Amyloid (1-42) CSF assay versus comparator assays and LC-MS/MS.

Background: Alzheimer's disease (AD) biomarkers, such as cerebrospinal fluid (CSF) amyloid-β (1-42; Aβ42), can provide high diagnostic accuracy. Several immunoassays are available for Aβ42 quantitation, but standardisation across assays remains an issue. We compared the Elecsys® β-Amyloid (1-42) CSF assay with three assays and two liquid chromatography tandem mass spectrometry (LC-MS/MS) methods.

Commutability of the certified reference materials for the standardization of β-amyloid 1-42 assay in human cerebrospinal fluid: lessons for tau and β-amyloid 1-40 measurements.

Background: The core Alzheimer's disease cerebrospinal fluid (CSF) biomarkers total tau (T-tau), phosphorylated tau (P-tau), β-amyloid 1-42 (Aβ42) and β-amyloid 1-40 (Aβ40) are increasing in importance and are now part of the research criteria for the diagnosis of the disease. The main aim of this study is to evaluate whether a set of certified reference materials (CRMs) are commutable for Aβ42 and to serve as a feasibility study for the other markers. This property is a prerequisite for the establishment of CRMs which will then be used by manufacturers to calibrate their assays against.

The impact of preanalytical variables on measuring cerebrospinal fluid biomarkers for Alzheimer's disease diagnosis: A review.

Introduction: Cerebrospinal fluid (CSF) biomarkers have the potential to improve the diagnostic accuracy of Alzheimer's disease, yet there is a lack of harmonized preanalytical CSF handling protocols.

Methods: This systematic review summarizes the current literature on the influence of preanalytical variables on CSF biomarker concentration. We evaluated the evidence for three core CSF biomarkers: β-amyloid 42, total tau, and phosphorylated tau.

Technical and clinical performance of a new assay to detect squamous cell carcinoma antigen levels for the differential diagnosis of cervical, lung, and head and neck cancer.

In squamous cell carcinoma, squamous cell carcinoma antigen levels are often elevated. This multi-center study evaluated the technical performance of a new Elecsys squamous cell carcinoma assay, which measures serum squamous cell carcinoma antigen 1 and 2 levels in an equimolar manner, and investigated the potential of squamous cell carcinoma antigen for differential diagnosis of cervical, lung, and head and neck squamous cell carcinoma.Assay precision and method comparison experiments were performed across three European sites.

Body Image Perception in Acromegaly Is Not Associated with Objective Acromegalic Changes but Depends on Depressive Symptoms.

Objective: Diagnosis of acromegaly is delayed up to 10 years after disease onset despite obvious external/objective changes such as bone and soft tissue deformities. We hypothesized that a lack of subjective perception of the disease state, possibly mediated by psychiatric or cognitive alterations, might contribute to the delayed initiation of a diagnostic workup.

Design: Cross-sectional study.

Comparison of Plasma and Urine Biomarker Performance in Acute Kidney Injury.

Background: New renal biomarkers measured in urine promise to increase specificity for risk stratification and early diagnosis of acute kidney injury (AKI) but concomitantly may be altered by urine concentration effects and chronic renal insufficiency. This study therefore directly compared the performance of AKI biomarkers in urine and plasma.

Methods: This single-center, prospective cohort study included 110 unselected adults undergoing cardiac surgery with cardiopulmonary bypass between 2009 and 2010.

NGAL, L-FABP, and KIM-1 in comparison to established markers of renal dysfunction.

Background: New urinary biomarkers like neutrophil gelatinase-associated lipocalin (NGAL), liver-type fatty acid binding protein (L-FABP), and kidney injury molecule-1 (KIM-1) open the opportunity to detect kidney injuries in early stages. Our study aimed at evaluating NGAL, L-FABP, and KIM-1 in comparison to established markers of urine protein differentiation for detection of renal dysfunction.

Methods: On the basis of the PROTIS expert system (for differentiation of glomerulo-/tubulopathy) urine and plasma samples of 263 randomly selected patients were routinely examined (urine: total protein, albumin, IgG, α1-microglobulin, creatinine, and dip stick results for leukocytes, blood, protein, glucose, pH, and nitrite; plasma: creatinine and cystatin C) followed by the analysis of the new urine biomarkers NGAL (CMIA), L-FABP (ECLIA), and KIM-1 (ELISA).