High immunoglobulin G subtype 4 is mainly seen in IgG4-related diseases, autoimmune diseases, hematologic diseases, and also in normal people.
Human immunoglobulins are categorized as IgG, IgA, IgM, IgD, and IgE, and IgG consists of four subtypes, of which immunoglobulin G subtype 4 (IgG4) belongs to one of them, accounting for about 4% of IgG.
Diseases associated with elevated IgG4 are collectively called IgG4-related diseases, such as retroperitoneal fibrosis, immune pancreatitis, sclerosing cholangitis, etc. Their main clinical features are multi-organ involvement, swelling and sclerosis of the affected organs, and markedly elevated serum IgG4 levels.
However, high IgG4 levels can also be seen in autoimmune diseases, such as vasculitis, and hematologic lymphoma.
When the immunoglobulin G subtype 4 is high, it is recommended to consult the rheumatology department in time, and improve the relevant examinations under the guidance of the doctor to clarify the diagnosis and early treatment.