Use

Evaluation for neuromyelitis optica spectrum disorder (NMOSD) via detection of aquaporin‑4 (AQP4) antibodies in serum, with reflex to MOG antibodies if AQP4 is negative. This aids in distinguishing NMOSD from multiple sclerosis by identifying AQP4-associated disease or MOG antibody–associated disorder, ensuring proper diagnosis and guiding appropriate immunotherapy.