{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,19]],"date-time":"2026-10-19T09:56:10Z","timestamp":1792403770988,"version":"4.4.0"},"reference-count":19,"publisher":"Walter de Gruyter GmbH","issue":"9","license":[{"start":{"date-parts":[[2025,5,8]],"date-time":"2025-05-08T00:00:00Z","timestamp":1746662400000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,8,26]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec id=\"j_cclm-2025-0125_abs_001\">\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>To investigate whether frozen storage duration influences \u03ba-FLC\u00a0index.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"j_cclm-2025-0125_abs_002\">\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>CSF and serum samples of patients with multiple sclerosis collected for routine diagnostic purposes had been stored at\u00a0\u221220\u202f\u00b0C. \u03ba-FLC and albumin concentrations were measured at two different timepoints, i.e.\u00a0before and after storage. The \u03ba-FLC index was calculated as (CSF \u03ba-FLC\/serum \u03ba-FLC)\/(CSF albumin\/serum albumin).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"j_cclm-2025-0125_abs_003\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>A total of 70 patients were included showing median CSF \u03ba-FLC concentration of 0.25 (25th-75th percentile: 0.12\u20130.43)\u202fmg\/dL, serum \u03ba-FLC concentration of 1.05 (0.86\u20131.34)\u202fmg\/dL, CSF albumin concentration of 17.7 (14.6\u201326.1)\u202fmg\/dL and serum albumin concentration of 4230 (3898\u20134488)\u202fmg\/dL. The \u03ba-FLC index was 44 (25\u2013108). With increasing frozen storage duration, the absolute concentrations of CSF \u03ba-FLC, serum \u03ba-FLC, CSF albumin and serum albumin decreased, while the \u03ba-FLC index remained stable. The observed changes in absolute concentrations evened out by using CSF\/serum ratios of \u03ba-FLC and albumin when calculating the \u03ba-FLC\u00a0index.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"j_cclm-2025-0125_abs_004\">\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Frozen storage at\u00a0\u221220\u202f\u00b0C has no relevant impact on \u03ba-FLC\u00a0index.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1515\/cclm-2025-0125","type":"journal-article","created":{"date-parts":[[2025,5,26]],"date-time":"2025-05-26T10:52:52Z","timestamp":1748256772000},"page":"1786-1791","source":"Crossref","is-referenced-by-count":3,"title":["Effect of long-term frozen storage on stability of kappa free light chain index"],"prefix":"10.1515","volume":"63","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-3081-854X","authenticated-orcid":false,"given":"Martin","family":"Schmidauer","sequence":"first","affiliation":[{"name":"Department of Neurology , Medical University of Innsbruck , Innsbruck , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Klaus","family":"Berek","sequence":"additional","affiliation":[{"name":"Department of Neurology , Medical University of Innsbruck , Innsbruck , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriel","family":"Bsteh","sequence":"additional","affiliation":[{"name":"Department of Neurology , Medical University of Vienna , Vienna , Austria"},{"name":"Comprehensive Center for Clinical Neurosciences and Mental Health , Medical University of Vienna , Vienna , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael","family":"Auer","sequence":"additional","affiliation":[{"name":"Department of Neurology , Medical University of Innsbruck , Innsbruck , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6909-6109","authenticated-orcid":false,"given":"Robert","family":"Barket","sequence":"additional","affiliation":[{"name":"Department of Neurology , Medical University of Innsbruck , Innsbruck , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Franziska","family":"Di Pauli","sequence":"additional","affiliation":[{"name":"Department of Neurology , Medical University of Innsbruck , Innsbruck , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michaela","family":"Hassler","sequence":"additional","affiliation":[{"name":"FH Campus Wien , University of Applied Sciences , Vienna , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dejan","family":"Milosajevic","sequence":"additional","affiliation":[{"name":"FH Campus Wien , University of Applied Sciences , Vienna , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anne","family":"Zinganell","sequence":"additional","affiliation":[{"name":"Department of Neurology , Medical University of Innsbruck , Innsbruck , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Janette","family":"Walde","sequence":"additional","affiliation":[{"name":"Department of Statistics, Faculty of Economics and Statistics , University of Innsbruck , Innsbruck , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Florian","family":"Deisenhammer","sequence":"additional","affiliation":[{"name":"Department of Neurology , Medical University of Innsbruck , Innsbruck , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Harald","family":"Hegen","sequence":"additional","affiliation":[{"name":"Department of Neurology , Medical University of Innsbruck , Innsbruck , Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"374","published-online":{"date-parts":[[2025,5,8]]},"reference":[{"key":"2026051215061127583_j_cclm-2025-0125_ref_001","doi-asserted-by":"crossref","unstructured":"Hegen, H, Berek, K, Deisenhammer, F. 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