IVIG & Plasmapheresis for Myasthenia Gravis Flares

If you have Myasthenia Gravis (MG) and are experiencing a severe symptom flare, a myasthenic crisis, or are preparing for a thymectomy surgery, your care team may recommend intravenous immunoglobulin (IVIG) or plasmapheresis (often called plasma exchange or PLEX) ^[1][2]. Unlike daily oral pills that take months to reach full strength, IVIG and plasmapheresis are fast-acting “rescue” treatments that provide rapid improvement, usually within a matter of days ^[1][3].

While they work differently, both therapies target the underlying immune system problem by addressing the harmful antibodies that disrupt communication between your nerves and muscles ^[4]. If you are in a myasthenic crisis, you will likely receive these treatments while staying in the hospital; if you are preparing for surgery or treating a non-emergency flare, they may be done in an outpatient infusion center ^[5].

What is Plasmapheresis (PLEX)?

Plasmapheresis acts like an advanced filter for your blood ^[4]. It physically removes the “bad” autoantibodies (such as AChR or MuSK antibodies) that are attacking your nerve-muscle connections ^[6].

The Patient Experience:
During PLEX, you will be hooked up to a specialized machine. Blood is gently drawn from your body through a tube and sent into the machine. If the veins in your arms are not large enough to handle the blood flow, a doctor may place a “central line”—a larger IV catheter in your chest or neck ^[5]. While this sounds intimidating, it is a safe, minor procedure done by a specialist using local numbing medication.

The machine separates your blood cells from your plasma (the liquid part of your blood containing the harmful antibodies). Your blood cells are then mixed with replacement fluids or donor plasma and safely returned to your body ^[5]. Because PLEX requires specialized equipment and trained staff, it is typically performed at larger medical centers.

• Timeframe: A typical treatment course involves 5 exchange sessions spread out over 7 to 14 days. Each session usually takes a few hours.
• Side Effects & Aftercare: Because fluids are shifting, you might experience low blood pressure, fatigue, or mild electrolyte imbalances like low calcium (which can cause tingling in your fingers or mouth) ^[5]. There is also a risk of infection or bruising related to the IV line ^[7]. You will likely feel tired after a session, so it is best to have a friend or family member drive you home. Research suggests PLEX may provide slightly faster short-term symptom improvement than IVIG during a crisis ^[3].

What is IVIG?

Intravenous immunoglobulin (IVIG) takes the opposite approach. Instead of filtering bad antibodies out, it floods your system with millions of “healthy” donor antibodies gathered from thousands of plasma donors ^[4]. This massive dose of normal antibodies helps neutralize and block the harmful antibodies, reducing the damage caused to your muscles ^[1].

The Patient Experience:
IVIG is given as a slow intravenous (IV) drip into your arm ^[4]. You sit comfortably in a chair or bed at the hospital or an outpatient infusion clinic while the fluid infuses into your vein. IVIG is generally more widely available than PLEX.

Before starting, your doctor will likely run blood tests to check your kidney function and ensure you do not have an IgA deficiency, which helps prevent rare allergic reactions or kidney issues ^[8].

• Timeframe: The total dose is usually divided over 2 to 5 consecutive days. Each daily infusion can last anywhere from 3 to 6 hours.
• Side Effects & Aftercare: Studies show IVIG has a highly favorable safety profile and is often linked to shorter hospital stays compared to PLEX ^[3][9]. The most common side effects are mild and include headaches, chills, fever, and muscle aches. Drinking plenty of water before and during the infusion can help prevent these. In rare cases, IVIG can cause more serious issues like aseptic meningitis (severe headache and stiff neck without infection) or blood clots ^[10][8]. Like PLEX, IVIG can leave you feeling drained, so arranging a ride home and planning to rest is highly recommended.

When Are These Treatments Needed?

Because the symptom relief from IVIG and PLEX is temporary—usually lasting 4 to 8 weeks—they are not meant to be standalone, long-term solutions. Instead, they act as a vital bridge while slower-acting medications (like immunosuppressant pills) take effect. Your doctor will likely recommend them if:

• You are in a myasthenic crisis: A life-threatening flare where weakness affects your breathing or swallowing ^[1].
• You have a severe flare-up: A sudden, significant worsening of your symptoms that needs quick intervention ^[3].
• You are scheduled for surgery: Particularly before a thymectomy (removal of the thymus gland) to ensure your muscles are as strong as possible, minimizing surgical risks and promoting a smoother recovery ^[2].

Both therapies are generally considered equally effective ^[11]. The choice between them often depends on your specific health factors, the severity of your symptoms, and what resources are available at your hospital ^[11][3].

Tips for Treatment Days

Whether you receive IVIG or PLEX, these sessions require sitting still for several hours. To make the experience more comfortable:

• Wear loose, warm clothing, as treatment rooms and hospitals can get chilly.
• Bring snacks, water, and something to pass the time (a book, tablet, or headphones).
• Arrange for someone to drive you home, as you may feel tired or washed out afterward.