Specifically, IVIG may be beneficial for multifocal motor neuropathy (MMN), chronic inflammatory demyelinating polyneuropathy (CIDP), Guillain-Barre syndrome (GBS), and more. It has also been shown to be efficacious for acute demyelinating neuropathy, myasthenia gravis in the short term, stiff-person syndrome, as well as a few inflammatory myopathies.

Since IVIG has such a wide profile of conditions, researchers explain that there are likely disease-specific pathways which impact the efficacy of the therapy for each condition. As a result, uncovering a general mechanism of how this therapy works through anti-inflammatory effects or immunomodulating effects has been difficult.

IVIG for GBS

A few trials have compared the use of IVIG to a therapy called plasmapheresis in GBS. Two investigations found that a singular dose of IVIG was very similar to treatment with plasmapheresis. Specifically, it aided in getting patients off ventilation and shortened their time to unassisted walking.

Variants of GBS include Miller-Fisher syndrome, acute axonal motor form of GBS, motor sensory forms of GBS, and acute dysautonomia. In each of these, IVIG also appears beneficial, but controlled studies are still needed.

IVIG for CIDP

Studies investigating the benefits of IVIG in CIDP have found that it is just as effective as plasmapheresis and steroids when used in the short term. A long-term trial called ICE, the largest investigation ever conducted for the condition, also found that the therapy was effective long-term.

This led to the very first indication of IVG approved by the FDA.

It is important to note that efficacy does vary by individual. Some patients tend to respond better to prednisone, some respond better to plasmapheresis, and some respond better to IVIG. But the message is clear – IVIG is very beneficial to a good portion of patients and should be made accessible.

The puzzle to uncover why some patients respond to one therapy better than another is still ongoing. However, so far, it appears that those who respond better to IVIG have-

• Less than one-year disease duration
• Electrophysiological signals of demyelination as well as a conduction block
• A relapsing course of disease

IVIG for MMN

Uniquely, MMN patients only respond to IVIG. There is no response for plasmapheresis or steroids. Patients taking the therapy have been shown to improve for 3-6 weeks following the start of treatment. This means that reinfusion is very predictable.

The therapy is typically started at 2 g/kg. However, the response is able to be maintained at just 1 g/kg.

Many clinical trials of IVIG have led to the approval of IVIG for MMN (a Baxter product).

IVIG and Other Conditions

IVIG has not had promising results for anti-myelin associated glycoprotein demyelinating neuropathy.

Conditions which may benefit from IVIG but efficacy have not yet been sufficiently demonstrated include-

• Diabetic amyotrophy
• Sensory neuropathies
• Vasculitic neuropathy
• Sjogren syndrome