biostudies-literatureUnknown16Comabella M<h4>Background</h4>Chitinase 3-like 1 (CHI3L1) is a prognostic biomarker in multiple sclerosis (MS). However, its clinical application is limited by a lack of standardized detection methods and concerns about preanalytical variability.<h4>Objectives</h4>This study aims to evaluate the impact of preanalytical factors (delayed processing of blood and repeated thawing/freezing) on serum CHI3L1 levels. Additionally, we sought to correlate CHI3L1 blood and cerebrospinal fluid (CSF) levels and identified its cellular source in peripheral blood mononuclear cells (PBMCs) from MS patients.<h4>Methods</h4>We used an in-house Single Molecule Array (Simoa) assay to measure CHI3L1 levels in serum, plasma, and CSF from MS patients and controls. The source of CHI3L1 production in PBMCs was determined by Frontiers in immunology1720914https://www.ebi.ac.uk/biostudies/studies/S-EPMC12907172biostudies-literatureImpact of preanalytical factors on blood CHI3L1 levels.PMC12907172Castillo MAroca MComabella MGutierrez LEixarch HFissolo NMontalban XLa Puma DVilaseca AVillar LMfalseImpact of preanalytical factors on blood CHI3L1 levels.<h4>Background</h4>Chitinase 3-like 1 (CHI3L1) is a prognostic biomarker in multiple sclerosis (MS). However, its clinical application is limited by a lack of standardized detection methods and concerns about preanalytical variability.<h4>Objectives</h4>This study aims to evaluate the impact of preanalytical factors (delayed processing of blood and repeated thawing/freezing) on serum CHI3L1 levels. Additionally, we sought to correlate CHI3L1 blood and cerebrospinal fluid (CSF) levels and identified its cellular source in peripheral blood mononuclear cells (PBMCs) from MS patients.<h4>Methods</h4>We used an in-house Single Molecule Array (Simoa) assay to measure CHI3L1 levels in serum, plasma, and CSF from MS patients and controls. The source of CHI3L1 production in PBMCs was determined by 2025-01-01T00:00:00Z20252026-07-16T05:05:35.162Z2026-07-09T10:38:12.087ZS-EPMC129071724170453310.3389/fimmu.2025.1720914