286093 20260413130803.0 10.1016/j.nbd.2026.107351 doi pmid:41831579 pmid 0969-9961 ISSN 1095-953X ISSN DZNE-2026-00389 English 570 Halbgebauer, Steffen P:(DE-2719)9002026 0 dzne Distinct cerebrospinal fluid profiles of astrocytic aquaporin-4 and GFAP in neuroinflammatory disorders. [Amsterdam] 2026 Elsevier article DRIVER Output Types/Journal article DataCite Journal Article journal journal PUB:(DE-HGF)16 1776078365_32198 PUB:(DE-HGF) ARTICLE BibTeX JOURNAL_ARTICLE ORCID Journal Article 0 EndNote Aquaporin 4 (AQP4), a water channel expressed in astrocytic end feet forming the blood brain barrier, is predominantly expressed in the central nervous system. Cerebrospinal fluid (CSF) AQP4 has now been suggested as a possible fluid biomarker in Alzheimer's disease. However, its diagnostic potential in primary neuroinflammatory diseases, where also AQP4 autoantibodies can circulate, has so far not been studied. We investigated the CSF of 301 patients for AQP4 and GFAP using ELISA. The single-center cohort consisted of patients with multiple sclerosis (n = 81), chronic inflammatory demyelinating polyneuropathy (n = 23), Guillain-Barré-Syndrome (n = 13), meningitis/ encephalitis (Men/Enc) (n = 19), myelin oligodendrocyte glycoprotein antibody disease (n = 6), neuromyelitis optica spectrum disease (NMOSD) (n = 12), and non-immune mediated polyneuropathy (NIP) patients (n = 49). 98 patients without acute or chronic neuroinflammation and neurodegneration served as controls. Both CSF AQP4 (r = 0.45 (95%CI: 0.36-0.54), p < 0.0001) and GFAP (r = 0.4 (95%CI: 0.30-0.49), p < 0.0001) correlated with age in the whole cohort. CSF AQP4 levels were elevated in the NIP group compared to control, MS and Men/Enc patients (p = 0.002, p = 0.029 and 0.005, respectively). When stratified further, the hereditary NIP patients (n = 26) displayed the highest AQP4 levels of all groups. CSF GFAP was elevated in the AQP4 autoantibody positive NMOSD group but was not increased in AQP4 autoantibody negative NMOSD patients. CSF AQP4 levels were similar in both NMOSD groups. Combining AQP4 and GFAP levels or calculating their ratio did not prominently enhance diagnostic discrimination. The study highlights the diagnostic potential of AQP4 as a fluid biomarker in neurological conditions, especially in peripheral neuropathies, while confirming GFAP as marker for astrocytic injury in autoantibody positive NMOSD patients. Our findings suggest that AQP4 and GFAP reflect different astrocytic processes in neurological diseases. 353 - Clinical and Health Care Research (POF4-353) G:(DE-HGF)POF4-353 POF4-353 POF IV 0 Dataset connected to CrossRef, PubMed, , Journals: pub.dzne.de Aquaporin 4 Other Astrocytes Other Biomarker Other Cerebrospinal fluid Other GFAP Other Aquaporin 4 NLM Chemicals AQP4 protein, human NLM Chemicals Biomarkers NLM Chemicals Glial Fibrillary Acidic Protein NLM Chemicals GFAP protein, human NLM Chemicals Autoantibodies NLM Chemicals Humans MeSH Aquaporin 4: cerebrospinal fluid MeSH Male MeSH Female MeSH Middle Aged MeSH Adult MeSH Biomarkers: cerebrospinal fluid MeSH Astrocytes: metabolism MeSH Glial Fibrillary Acidic Protein: cerebrospinal fluid MeSH Aged MeSH Neuroinflammatory Diseases: cerebrospinal fluid MeSH Neuroinflammatory Diseases: diagnosis MeSH Cohort Studies MeSH Young Adult MeSH Autoantibodies: cerebrospinal fluid MeSH Winger, Niklas 1 Elmas, Zeynep 2 Fazeli, Badrieh 3 Bachhuber, Franziska 4 Erhart, Deborah K 5 Soylu, Önder 6 Klassen, Paula P:(DE-2719)9001969 7 dzne Senel, Makbule 8 Dorst, Johannes P:(DE-2719)9001951 9 dzne Haeusler, Karl Georg 10 Weishaupt, Jochen H P:(DE-2719)9000455 11 Otto, Markus 12 Tumani, Hayrettin P:(DE-2719)9002007 13 dzne 10.1016/j.nbd.2026.107351 Vol. 222, p. 107351 - PERI:(DE-600)1471408-5 107351 Neurobiology of disease 222 2026 0969-9961 http://pub.dzne.de/record/286093/files/DZNE-2026-00389.pdf Restricted http://pub.dzne.de/record/286093/files/DZNE-2026-00389.pdf?subformat=pdfa pdfa Restricted External Institute I:(DE-HGF)0 Extern 0 P:(DE-2719)9002026 Deutsches Zentrum für Neurodegenerative Erkrankungen I:(DE-588)1065079516 DZNE 7 P:(DE-2719)9001969 External Institute I:(DE-HGF)0 Extern 9 P:(DE-2719)9001951 Deutsches Zentrum für Neurodegenerative Erkrankungen I:(DE-588)1065079516 DZNE 11 P:(DE-2719)9000455 External Institute I:(DE-HGF)0 Extern 13 P:(DE-2719)9002007 DE-HGF Gesundheit Neurodegenerative Diseases G:(DE-HGF)POF4-350 G:(DE-HGF)POF4-353 G:(DE-HGF)POF4 G:(DE-HGF)POF4-300 G:(DE-HGF)POF Clinical and Health Care Research 0 DBCoverage StatID:(DE-HGF)0200 StatID SCOPUS 2025-11-11 DBCoverage StatID:(DE-HGF)0300 StatID Medline 2025-11-11 DBCoverage StatID:(DE-HGF)0501 StatID DOAJ Seal 2025-08-21T14:53:16Z DBCoverage StatID:(DE-HGF)0500 StatID DOAJ 2025-08-21T14:53:16Z Peer Review StatID:(DE-HGF)0030 StatID DOAJ : Anonymous peer review 2025-08-21T14:53:16Z DBCoverage StatID:(DE-HGF)0199 StatID Clarivate Analytics Master Journal List 2025-11-11 DBCoverage StatID:(DE-HGF)1190 StatID Biological Abstracts 2025-11-11 DBCoverage StatID:(DE-HGF)0160 StatID Essential Science Indicators 2025-11-11 WoS StatID:(DE-HGF)0113 StatID Science Citation Index Expanded 2025-11-11 DBCoverage StatID:(DE-HGF)0150 StatID Web of Science Core Collection 2025-11-11 DBCoverage StatID:(DE-HGF)1030 StatID Current Contents - Life Sciences 2025-11-11 DBCoverage StatID:(DE-HGF)1050 StatID BIOSIS Previews 2025-11-11 JCR StatID:(DE-HGF)0100 StatID NEUROBIOL DIS : 2022 2025-11-11 DBCoverage StatID:(DE-HGF)0600 StatID Ebsco Academic Search 2025-11-11 Peer Review StatID:(DE-HGF)0030 StatID ASC 2025-11-11 IF >= 5 StatID:(DE-HGF)9905 StatID NEUROBIOL DIS : 2022 2025-11-11 Article Processing Charges StatID:(DE-HGF)0561 StatID 2025-11-11 Fees StatID:(DE-HGF)0700 StatID 2025-11-11 I:(DE-2719)5000077 Clinical Study Center (Ulm) Clinical Study Center (Ulm) 0 journal EDITORS VDBINPRINT I:(DE-2719)5000077 UNRESTRICTED