By Michelle Greer, RN, MBA
The expected or desired response to immune globulin (IG) treatment depends on the diagnosis for which it is being administered. But, the bottom line is, in almost all conditions, there should be a noticeable improvement. That’s why it’s very important for patients to discuss with their physician how they are feeling once treatment has begun. This will help determine if IG therapy is working. If a physician determines the therapy is not working, he or she may try another dose or frequency, or decide to discontinue treatment and look at other options.
It is important to note that many patients simply feel better when being treated with intravenous IG or subcutaneous IG, yet their presenting symptoms persist. Patients may report increased energy and changes in their skin and hair, and they may just have a general sense of feeling good. But, this is not the ultimate goal of therapy. Let’s take a look at the specific expected responses.
For primary immune deficiency diseases or secondary immune deficiencies as seen in chronic lymphocytic leukemia, the goal of IVIG is to replace the antibodies that are lacking or not functioning properly. This is known as replacement therapy. The response should then be a reduced incidence of infection, fewer severe infections, fewer missed days of school or work, and a better quality of life. A physician will likely order lab tests to evaluate the level of immunoglobulins (IgGs) in a patient to assist in determining the benefit of replacement therapy. But the infection rate is very important and specific to the individual. For instance, an IgG level for one person can mean no infections, while for another, it’s not sufficient to keep them from getting ill. The details of infections are important to note, as well such as the type, severity and frequency, as well as what type of treatment is required, whether there are missed work or school days, and if hospitalization is required. If infections still persist, a physician might consider changing the total monthly grams or even switching the patient to SCIG.
For autoimmune diseases, IVIG treatment is considered immunomodulation. This means that the IG therapy suppresses the immune response so that the autoantibody production is halted and the symptoms subside. The mechanism of action in autoimmune diseases is complex and not clearly understood. It also depends on the disease state.
For neuromuscular diseases such as chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy and myasthenia gravis, or muscle diseases such as myositis, the desired response is decreased muscle weakness and improved ability to perform routine activities like walking, climbing stairs and lifting objects. Assessing response depends on the presenting symptoms. If a patient had difficulty rising from a chair, this should get easier. If he or she had difficulty writing, that should improve.
For autoimmune dermatological diseases such as pemphigus and pemphigoid, the goal is to stop the formation of new blisters and allow existing ones to heal.
In general, IVIG is not a curative treatment. In immune deficiencies, it is typically a lifelong therapy to replace what the immune system is not producing effectively on its own. In autoimmune disease, treatment length is dependent on response, but the goal is maximum function as a result of the lowest amount of IG therapy. This includes discontinuing IG altogether. Many people achieve maximum effect, after which IG therapy is discontinued and the effect remains. Others may need repeat courses if symptoms return. What response have you experienced for your particular condition?