Which Ig therapy is right for you?

When Dr. Richard Wasserman prescribes immunoglobulin (Ig) therapy for his patients with primary immunodeficiency, he doesn’t feel bound by the recommended dose listed on the package inserts of the product. Instead, he considers the person’s biological trough – that is, how much Ig it takes to keep his patient free from infection.

Dr. Wasserman’s approach, along with that of many immunologists, is firmly supported by clinical studies that show the more Ig a doctor gives, the better a patient does. In fact, in an examination of 17 clinical studies, evidence showed that for every increase of 100 milligrams per kilogram per month of Ig a person with PI received, that person’s risk of pneumonia decreased by 27 percent. The higher the dose of Ig, the higher the level of Ig in the bloodstream, and the lower the risk of infection, explained Wasserman.

“The point here is that each individual patient has their own biological trough. What that says is that the right dose of gamma globulin for a given individual patient is the dose that keeps them well,” said Dr. Wasserman.

Dr. Wasserman, medical director of Pediatric Allergy and Immunology at Medical City Children’s Hospital, and managing partner at Allergy Partners of North Texas, shared this information during an August 18 IDF online education forum entitled, “Immunoglobulin (Ig) Therapy: Finding the Right Fit for You.”

Ig therapy plays a significant role in the lives of many people diagnosed with PI, as it provides lifesaving antibodies that they cannot produce. Dr. Wasserman’s hour-long presentation defined Ig and Ig replacement therapy, discussed the importance of the need for Ig therapy, explored the positives and negatives of available modes of Ig administration, and reviewed the various methods of how a person can self-administer Ig.

Dr. Wasserman discussed both intravenous immunoglobulin (IVIG) and subcutaneous (SCIG) therapies, common reactions to the therapies, ways to reduce side effects, and the importance of communicating with a provider about what works best for the person with PI. He said there are many products that are available. They are all equal, but not identical, so people should find the one that’s right for them.

IVIG, or intravenous immunoglobulin, is administered straight into the vein by a healthcare provider, either in the home, at an infusion suite in a doctor’s office, or at an infusion center run by a medical group, specialty pharmacy, or hospital. The bioavailability of IVIG is 100 percent, which means that all of the Ig goes into the bloodstream. It usually requires only one site on the body for administration and is given every three to four weeks. Side effects that may occur include headache, malaise, muscle aches, fatigue, cough, and fever.

A major alternative to IVIG is SCIG, subcutaneous immunoglobulin. SCIG is administered at home by the person with PI. Typically, several needles are placed in a fatty area of the body like the stomach or thighs. The Ig goes into the bloodstream via small vessels called lymphatics that are present under the skin in all parts of the body. Because the bioavailability of SCIG is 63 percent, some patients require a higher monthly dose than if they were getting IVIG. Administered every week, or every other week, IVIG can cause side effects at the site of infusion such as redness, swelling, itch, and discomfort, but those side effects usually decrease with time.

Another option is enzyme-facilitated subcutaneous Ig administration. In this self-administered modality, the infusion contains an enzyme that reversibly breaks up some of the subcutaneous filler material and allows for tiny microchannels. The micro-channels facilitate the administration of a large amount of fluid subcutaneously. The advantage to enzyme-facilitated SCIG is that large doses of IG (as much as 20 ounces) may be administered less frequently at one site. It can be administered at home, every two to four weeks.

In addition to describing the Ig administration options, Dr. Wasserman recommended those with PI visit the IDF website to download publications including the IDF Guide to Ig Therapy, and explore the Immunoglobulin Therapy and Other Medical Therapies for Antibody Deficiencies section of the site.

Other aspects related to Ig that should be considered are how frequently doctor check-ups take place, how often infections and antibiotic administrations occur, the tolerability of the Ig modality, technical infusion-related problems, and side effects. Don’t be afraid to ask questions, urged Dr. Wasserman, and be aware that there are programs for financing Ig, as well as for providing psychological and clinical support.

Dr. Wasserman concluded by saying that the keys to success are understanding your Ig therapy, knowing what to expect, knowing your options, and keeping your physician informed.

Watch the full presentation here.