% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Halbgebauer:286093,
      author       = {Halbgebauer, Steffen and Winger, Niklas and Elmas, Zeynep
                      and Fazeli, Badrieh and Bachhuber, Franziska and Erhart,
                      Deborah K and Soylu, Önder and Klassen, Paula and Senel,
                      Makbule and Dorst, Johannes and Haeusler, Karl Georg and
                      Weishaupt, Jochen H and Otto, Markus and Tumani, Hayrettin},
      title        = {{D}istinct cerebrospinal fluid profiles of astrocytic
                      aquaporin-4 and {GFAP} in neuroinflammatory disorders.},
      journal      = {Neurobiology of disease},
      volume       = {222},
      issn         = {0969-9961},
      address      = {[Amsterdam]},
      publisher    = {Elsevier},
      reportid     = {DZNE-2026-00389},
      pages        = {107351},
      year         = {2026},
      abstract     = {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.},
      keywords     = {Humans / Aquaporin 4: cerebrospinal fluid / Male / Female /
                      Middle Aged / Adult / Biomarkers: cerebrospinal fluid /
                      Astrocytes: metabolism / Glial Fibrillary Acidic Protein:
                      cerebrospinal fluid / Aged / Neuroinflammatory Diseases:
                      cerebrospinal fluid / Neuroinflammatory Diseases: diagnosis
                      / Cohort Studies / Young Adult / Autoantibodies:
                      cerebrospinal fluid / 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)},
      cin          = {Clinical Study Center (Ulm)},
      ddc          = {570},
      cid          = {I:(DE-2719)5000077},
      pnm          = {353 - Clinical and Health Care Research (POF4-353)},
      pid          = {G:(DE-HGF)POF4-353},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:41831579},
      doi          = {10.1016/j.nbd.2026.107351},
      url          = {https://pub.dzne.de/record/286093},
}