B-102 Harmonizing cerebrospinal fluid analysis for multiple sclerosis investigation: An update from the hCAMI subcommittee of the Canadian Society of Clinical Chemists (CSCC)

Background Laboratory tests are increasingly important for diagnosing multiple sclerosis (MS). Cerebrospinal fluid (CSF) laboratory testing, including detection of CSF oligoclonal bands (OCB), aids in the diagnosis of MS but significant variability in reporting practices across Canadian clinical laboratories has been shown. To address this issue, the Harmonized CSF Analysis for MS Investigation (hCAMI) subcommittee of the Canadian Society of Clinical Chemists (CSCC) Reference Interval Harmonization (hRI) Working Group was formed. Methods The hCAMI subcommittee, comprised of clinical chemists and neurologists, identified key areas of CSF laboratory testing for MS investigation that require harmonization and formulated specific questions for targeted recommendations. The subcommittee comprehensively reviewed the literature, surveyed clinical chemists regarding current practices and neurologists on reporting preferences, and conducted studies to answer these questions. Recommendation statements were drafted and will undergo the Delphi process for refinement to ultimately generate evidence-based consensus statements. Results Six key areas for harmonization were identified: (1) quality control practices, (2) timing considerations for matched CSF and serum sample collection, (3) reporting protocols for band counts, (4) interpretation and follow-up for other patterns (i.e., monoclonal gammopathy, inflammatory response), (5) handling of matched band intensity variations, and (6) defining panel components and reference intervals/decision limits. Literature and data were reviewed for each key area. Draft recommendations were developed and will undergo iterative refinement via the Delphi process. Conclusion Harmonized laboratory reporting recommendations will lead to consistency and alignment of CSF laboratory testing for diagnosis of MS across Canada. This subcommittee’s efforts will promote evidence-based standardized reporting practices to improve diagnostic accuracy and patient care.