IgG is divided into four subclasses: IgG1, IgG2, IgG3, and IgG4, each with distinct functions and distributions. → IgG1: Predominantly involved in responses to protein antigens. → IgG2: Primarily responds to polysaccharide antigens and is important in the defense against bacterial infections.

Individuals with IgG subclass deficiency are defined as having recurrent infections, persistently low levels of one or more IgG subclasses, and normal concentrations of total IgG, IgM, and IgA. IgG2 or IgG3 deficiencies are the most common IgG subclass deficiencies.

What are IgG deficiencies? An IgG deficiency is a health problem in which your body doesn’t make enough Immunoglobulin G (IgG). People with IgG deficiency are more likely to get infections. When your body feels it is under attack, it makes special proteins called immunoglobulins or antibodies. These antibodies are made by the plasma cells.

Of the five immunoglobulin isotypes, immunoglobulin G (IgG) is most abundant in human serum. The four subclasses, IgG1, IgG2, IgG3, and IgG4, which are highly conserved, differ in their constant region, particularly in their hinges and upper CH2 ...

IgG2 is the main antibody present in response to polysaccharide antigens, and IgG4 participates in responses to nematodes and is observed in chronic antigenic stimulation. 9 All IgG subclasses exist as monomers and have a high structural similarity; however, minor differences make for distinct biologic effects.

Most patients with IgG2 deficiency present with recurrent infections, usually sinusitis, otitis, or pulmonary infections. Children with deficiency of IgG subclass 2 often have deficient antibody responses to polysaccharide antigens, including bacterial antigens associated with Haemophilus influenzae type B and Streptococcus pneumoniae .

2024年1月23日 · Immunoglobulin G (IgG) is the predominant glycoprotein present in human serum, constituting about 75-80% of total immunoglobulin in humans which accounts for 10 to 16mg/ml serum concentration and is produced as part of the secondary immune response to …

Human IgG2 antibody displays distinct therapeutically-useful properties compared with the IgG1, IgG3, and IgG4 antibody subclasses. IgG2 is the second most abundant IgG subclass, being able to bind human FcγRII/FcγRIII but not to FcγRI or complement C1q.

IgG2 as a proportion of IgG subclasses was 20% in the present patients, of whom 67% had subnormal IgG. In normal adults, IgG2 represents ~one-third of serum IgG [1,2]. These observations indicate that both relative and absolute levels …

IgG2. IgG2, the second largest of IgG isotypes, comprises 20–25% of the main subclass and is the prevalent immune response against carbohydrate/polysaccharide antigens. “Adult” concentrations are usually reached by 6 or 7 years old.