P01861

IgG4 also known as IGHG4 is a unique subclass of immunoglobulin G that plays a crucial role in the immune response, particularly in modulating allergic reactions and autoimmune diseases. Unlike other IgG subclasses, IgG4 is known for its ability to undergo a process called "Fab-arm exchange," which allows IgG4 to form bispecific antibodies that can bind to two different antigens simultaneously. This characteristic is significant as IgG4 can help in regulating immune responses and reducing inflammation, making IgG4 an important player in maintaining immune tolerance. Furthermore, research has indicated that low concentrations of IgG4 are often found in patients with recurrent respiratory tract infections, suggesting IgG4′s potential role in immune system dysfunction.