Conditions / AQP4 – anti-aquaporin-4 (AQP4) antibody

AQP4 – anti-aquaporin-4 (AQP4) antibody

Overview

The anti-aquaporin-4 (AQP4) antibody is a specific immune protein that targets aquaporin-4, a water channel found on cells in the central nervous system—especially around the spinal cord and optic nerves. The presence of this antibody is a key marker for Neuromyelitis Optica Spectrum Disorder (NMOSD), an autoimmune condition that causes inflammation and damage to these critical areas of the brain and spinal cord.

Why It Matters

Testing positive for AQP4 antibodies strongly supports a diagnosis of NMOSD and helps distinguish it from multiple sclerosis (MS), which has different treatments and disease progression. About 70–80% of people with NMOSD test positive for AQP4 antibodies.

Symptoms Associated with AQP4+ NMOSD

When AQP4 antibodies attack, they can cause severe inflammation and neurological symptoms, including:

• Vision loss or eye pain (optic neuritis)

• Weakness or numbness in the limbs

• Difficulty walking or paralysis

• Bladder or bowel dysfunction

• Persistent nausea, vomiting, or hiccups (from brainstem involvement)

Symptoms often occur in relapses or attacks, which can cause lasting damage if not treated promptly.

When to Get Tested

Your doctor may order an AQP4 antibody blood test if you experience:

• Symptoms of optic neuritis or transverse myelitis

• Recurrent neurological attacks with unclear cause

• MRI findings suggestive of NMOSD rather than MS

• Poor response to typical MS treatments

Causes and Risk Factors

The exact cause of AQP4 antibody production is unknown, but NMOSD is believed to involve a combination of:

• Genetic predisposition

• Autoimmune activity (sometimes linked to other autoimmune conditions like lupus or Sjögren’s syndrome)

• Environmental or infectious triggers

Women, especially those of African, Asian, or Latin American descent, are more frequently affected.

Medication and Treatment Risks

AQP4+ NMOSD is typically treated with medications that suppress the immune system and prevent relapses.

Common treatments include:

• Eculizumab, inebilizumab, satralizumab, or rituximab

• Corticosteroids during acute attacks

• Plasma exchange (PLEX) for severe relapses

Risks and side effects:

• Increased risk of infections due to immune suppression

• Infusion-related reactions

• Liver toxicity with some medications

Disclaimer: Always consult your healthcare provider about risks, side effects, and interactions with other medications or supplements.

Medications We Offer

At Thrivewell Infusion, we provide treatments for AQP4-Antibody Positive Disorders, helping reduce relapses, protect neurological function, and improve long-term outcomes.

• Uplizna

• Vyepti

Start your treatment