The value of CSF diagnostic and prognostic biomarkers in NMOSD and MOGAD in real-life use.

BACKGROUND

Diagnosing neuromyelitis optica spectrum disorder (NMOSD) may be challenging owing to overlapping clinical features with multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), particularly in AQP4-IgG seronegative NMOSD patients. We evaluated cerebrospinal fluid (CSF) biomarkers, specifically glial fibrillary acidic protein (GFAP) and albumin quotient (QAlb), to improve diagnostic accuracy in NMOSD.

METHODS

In this retrospective study, we analyzed CSF samples for biomarkers GFAP, QAlb, neurofilament light, and total-Tau, from patients with AQP4-NMOSD, DNNMOSD, MOGAD, and MS in the Region Västra Götaland, Sweden. Receiver operating characteristic (ROC) analysis with calculation of the area under the curve (AUC) was used to identify optimal cut-off levels for discriminating AQP4-NMOSD from the other groups. Logistic regression models assessed the diagnostic power of GFAP and QAlb combined.

RESULTS

Patients with AQP4-NMOSD (N = 19) had significantly higher CSF GFAP levels than the others: median 2470 ng/L vs 330 ng/L (p < 0.001). The GFAP cutoff >715 ng/L gave a sensitivity of 81 % and specificity of 92 %. Combining GFAP and QAlb further increased the diagnostic accuracy (AUC = 0.96). MOGAD patients (N = 29) had the highest CSF lymphocyte counts, with elevated lymphocyte counts correlating with polyphasic MOGAD (R = 0.63; p = 0.016).

CONCLUSION

CSF GFAP is a valuable biomarker for distinguishing AQP4-NMOSD from other demyelinating diseases: Combining GFAP with QAlb enhances diagnostic precision.