Gammaglobulin

Gammaglobulin is the fraction of human plasma that contains immunoglobulins, primarily immunoglobulin G (IgG). Clinically, it is used as immunoglobulin therapy in the form of intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (SCIG). It is derived from pooled plasma from thousands of healthy donors and undergoes pathogen inactivation, purification, and formulation for medical use.

Gammaglobulin preparations consist mainly of IgG, with small amounts of other immunoglobulins such as IgA and IgM depending on the product. They are produced from screened donor plasma and prepared for intravenous or subcutaneous administration. IVIG and SCIG provide passive immunity and can modulate immune activity, a feature that underlies both replacement and immunomodulatory uses.

Indications include replacement therapy for primary immunodeficiency disorders (for example, X-linked agammaglobulinemia and common variable immunodeficiency) and acquired hypogammaglobulinemia due to disease or treatment. At higher doses, IVIG has immunomodulatory effects and is used in various autoimmune and inflammatory conditions, such as immune thrombocytopenia, Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, Kawasaki disease in children, and certain rheumatic or neurologic disorders.

dosing varies with indication and patient weight. Replacement regimens commonly use about 400–600 mg/kg every 3–4 weeks; higher-dose protocols may reach 2 g/kg over several days for acute autoimmune conditions. SCIG typically involves more frequent, smaller doses (for example, weekly administration).

Adverse effects can include infusion reactions, headaches, fever, or nausea. Serious risks include anaphylaxis in IgA-deficient individuals, aseptic meningitis, thromboembolism, and renal dysfunction. Products are monitored for safety, and administration is tailored to individual patient needs.