Low Aquaporin-4 antibody (AQP4-IgG): what it means
A Aquaporin-4 antibody (AQP4-IgG) result below the normal range is considered low. Here is what a reduced Aquaporin-4 antibody (AQP4-IgG) can point to, and when it is worth discussing with a doctor.
Reference range: negative is normal; the hallmark antibody of neuromyelitis optica spectrum disorder (NMOSD) — a positive result distinguishes it from multiple sclerosis and changes treatment
Understand your full resultWhat a low Aquaporin-4 antibody (AQP4-IgG) can mean
- Negative — the normal result; makes NMOSD less likely but does not fully exclude it.
- MOG-antibody disease or seronegative NMOSD — a negative AQP4 result in someone with typical symptoms may reflect these, needing further testing.
When to discuss with a doctor
AQP4 antibody testing is a specialist request, ordered by neurologists when someone has inflammation of the optic nerve (optic neuritis, with painful loss of vision) or the spinal cord (transverse myelitis, with weakness, numbness or bladder problems), especially when attacks are severe or recurrent, or when telling NMOSD apart from multiple sclerosis will change treatment. A positive result confirms NMOSD and directs specific therapy while steering away from certain multiple-sclerosis drugs that can worsen it. Acute attacks — sudden vision loss or new limb weakness — are urgent and need immediate neurological care. Mediora.AI shows the AQP4 antibody in context, but this is a specialist result: its interpretation, and the diagnosis and treatment of NMOSD, belong with a neurologist.
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Upload your test - freeMediora.AI is informational - interpretation, not a diagnosis. A single out-of-range value is common and often benign; always discuss decisions with your doctor.