Immunoglobulin therapy is a medical treatment that uses antibodies (immunoglobulins) to support or modulate the body’s immune system. It provides functional antibodies to individuals with compromised or overactive immune systems. This helps the body fight infections and regulate immune responses, improving health outcomes for various conditions.
Understanding Immunoglobulin Therapy
Immunoglobulins (antibodies) are naturally occurring proteins produced by the immune system to identify and neutralize foreign invaders like bacteria and viruses. They recognize specific threats and initiate a targeted immune response. The therapy introduces a concentrated mixture of these proteins into the patient’s system.
The immunoglobulins used in therapy are derived from the pooled plasma of thousands of healthy human donors. This ensures a broad spectrum of antibodies, capable of combating a wide range of pathogens. This supply replaces missing antibodies in individuals with impaired production or modulates an overactive immune response in autoimmune conditions. For immunodeficiency, the therapy provides passive immunity, supplying tools to fight infections. For autoimmune disorders, high doses regulate immune cell activity and reduce inflammation.
Conditions Where Immunoglobulin Therapy is Used
Immunoglobulin therapy is prescribed for a variety of conditions, including primary immunodeficiency disorders, autoimmune diseases, and certain neurological conditions. For primary immunodeficiency disorders like common variable immunodeficiency (CVID) and X-linked agammaglobulinemia (XLA), the body lacks sufficient or properly functioning antibodies. The therapy replaces missing functional antibodies to prevent recurrent and severe infections.
In autoimmune diseases, the immune system attacks healthy tissues. Conditions such as Guillain-Barré Syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP), and immune thrombocytopenic purpura (ITP) benefit from this therapy. The therapy modulates the immune response, reducing harmful attacks on the body’s cells and tissues. It stabilizes nerve function and improves mobility in neurological conditions like CIDP, and in ITP, it increases platelet counts.
It is also used for specific neurological conditions, including multifocal motor neuropathy (MMN) and inflammatory myositis conditions like dermatomyositis. For these, immunoglobulins reduce inflammation and prevent further damage to nerve or muscle cells. It is also considered for other conditions, such as Kawasaki disease, pediatric HIV infection, and organ transplantation, where immune modulation or infection prevention is needed.
Receiving Immunoglobulin Therapy
Immunoglobulin therapy is administered through intravenous (IVIG) and subcutaneous (SCIG) methods. IVIG involves infusing the immunoglobulin directly into a vein, typically in the arm. This method allows for a rapid delivery of a large dose of antibodies into the bloodstream, resulting in an initial peak in immunoglobulin G (IgG) levels.
IVIG infusions generally take a few hours, typically two to four, with duration depending on dosage and patient tolerance. These treatments are administered every three to four weeks in a hospital, clinic, or at home by a healthcare professional. Patients may receive pre-medications, such as antihistamines or pain relievers, to manage potential infusion-related reactions.
SCIG involves administering immunoglobulin into the subcutaneous tissue, under the skin, often in the abdomen or thighs. This allows for slower, more consistent absorption of immunoglobulins into the bloodstream, maintaining stable IgG levels between doses. SCIG infusions can be given more frequently, from daily to weekly or bi-weekly, and can often be self-administered at home after training. Infusion volume per site is limited, so multiple sites may be used simultaneously, spaced at least two inches apart, and rotated with each administration.
Managing Potential Side Effects
Immunoglobulin therapy is generally well-tolerated, but patients may experience side effects during or after treatment. Common mild side effects associated with IVIG include headaches, chills, fever, flushing, and muscle aches or fatigue. These reactions often occur during the first dose or when a new brand of immunoglobulin is used. To mitigate these, healthcare providers may recommend slowing the infusion rate, ensuring the product is at room temperature, and encouraging oral hydration before, during, and after the infusion. Pre-medications like acetaminophen or antihistamines can also be given to alleviate symptoms.
SCIG generally has milder systemic side effects than IVIG, but localized reactions at the infusion site are common. These include redness, swelling, itching, or a hard lump, which typically resolve within a day or two. Over time, the skin often adjusts to the medication, and these site reactions may become less frequent. Applying cold or warm compresses to the infusion site can counteract irritation.
Less common but more serious side effects include severe headaches with stiff neck and light sensitivity (aseptic meningitis), kidney problems, or allergic reactions. Patients should communicate any symptoms they experience to their healthcare provider. Prompt reporting allows the healthcare team to adjust the treatment plan, such as modifying the dose or infusion rate, or to provide medical intervention to manage or prevent adverse reactions.