The Calm Between Storms: Serum Biomarkers in Assessing Interattack Astrocytopathy in Neuromyelitis Optica Spectrum Disorder

摘要

Cytoskeletal structural proteins, released when cellular damage occurs, are biomarker candidates under investigation for many neurologic diseases. Among the potential markers, neurofilament light chain (NfL), expressed in neurons, and glial fibrillary acidic protein (GFAP), expressed in astrocytes, can now be measured in the serum (sNfL and sGFAP) thanks to advances in highly sensitive analytic methodologies, with strong correlation to CSF levels. Early studies of sNfL and sGFAP in MS and neuromyelitis optica spectrum disorder (NMOSD) focus on potential roles as biomarkers of treatment response, risk for relapse, and risk for disability progression.1-4 Not surprisingly, levels of sGFAP increase during NMOSD relapses, as the disease process is primarily an astrocytopathy mediated by AQP4-IgG.4,5 More complex questions include how these levels change in between relapses, during disease stability, and if this could be useful in determining treatment response, predicting disability progression, or guiding therapy.