serum immunoglobulin subclass G

There are four subclasses of IgG, namely IgG1, IgG2, IgG3, and IgG4, and their contents are sequentially decreased. The physiological characteristics and functions of the four subtypes are also different. For example, IgG1, IgG2 and IgG3 form a complex with the antigen to activate complement through the classical pathway, in which IgG3 activates complement, and IgG4 aggregates through alternative pathways. Activate complement. The ability of each subclass to cross the placenta, bind to Staphylococcal Protein A, and bind to different types of Fc segment receptors are not identical. They function differently in immune responses, such as IgG1 and IgG3 responding to bacterial and viral antigenic proteins, while IgG2 is primarily responsible for S. pneumoniae, group A streptococci, and Haemophilus influenzae capsular polysaccharide antigens. In response, IgG4 is associated with chronic allergic stimuli, and even after desensitization, it can still produce an immune response to allergens and inhibit IgE production. The IgG subclass may be associated with infection recurrence, immunodeficiency and autoimmune diseases, and thus the determination of IgG subclasses is important for these diseases. Even when the total IgG level is within the normal range, subclass assignment of IgG may be disordered. Because of the small structural differences among the four subclasses, it is difficult to prepare subclass antisera, and it is mainly detected by monoclonal antibodies. The measurement methods include radioimmunoassay, one-way diffusion, and ELISA. Basic Information Specialist classification: cardiovascular examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Reminder: The possibility of IgG subclass defects should be considered in all children with recurrent infections, bronchial asthma and/or chronic obstructive bronchitis. Moreover, for all high-risk immunocompromised patients, such as bone marrow transplants, patients need to measure IgG subclass levels. Normal value ELISA method: IgG 14.2 to 12.9 g / L; IgG21.4 ~ 7.5g / L; IgG30.4～1.3g/L; IgG4 is 0.01 to 1.5 g/L. Clinical significance (1) Increased serum concentration of IgG subclasses Allergic diseases, asthma, idiopathic eczema, dermatitis and other IgG4 can be elevated, chronic pyogenic bacteria, IgG2, IgG3, gallbladder fibrosis, elevated IgG1 in multiple sclerosis . (2) IgG subclass serum concentration reduction or defects: 1 autoimmune or atopic reactive disease; children with bronchial asthma IgG2, IgG3 content can be reduced; type I diabetes, juvenile diabetes IgG various subclasses can be reduced; primary thrombocytopenic purpura IgG2, IgG4 content decreased; system The content of IgG3 and IgG4 in lupus erythematosus can be reduced. 2 immunodeficient bone marrow transplantation, HIV infection, IgA deficiency can occur IgG2, IgG4 defects; common variant immunodeficiency disease (CVID) can occur IgG1, IgG2, IgG4 defects; large doses of cortisol hormone application can occur IgG3, IgG2 deficiency; IgG4 deficiency can occur in patients with IgM deficiency; IgG2 deficiency can occur in radiation injury and chemotherapy; IgG4 deficiency can occur in Wei-Ao syndrome. 3 Infection with IgG2 deficiency is prone to otitis media in children caused by pneumococcal disease; IgG2, IgG4 deficiency can lead to repeated infection of capsular bacteria; lack of IgG2, IgG3, IgG4 can cause repeated infection of the lungs, bronchitis. 4 other diseases, alcoholic liver disease, ataxia - telangiectasia, IgG2, IgG4 content decreased; IgG2 decreased after intestinal surgery; IgG1 decreased in the late stage of renal failure; IgG1, IgG2 decreased in nephrotic syndrome. High results may be diseases: asthma, eczema, bronchitis, otitis media precautions In conclusion, the possibility of IgG subclass defects should be considered in all children with recurrent infections, bronchial asthma, and/or chronic obstructive bronchitis. Moreover, for all high-risk immunocompromised patients, such as bone marrow transplants, patients need to measure IgG subclass levels. Inspection process Same as one-way diffusion method and ELISA method. Not suitable for the crowd There are no special taboos. Adverse reactions and risks No related complications and hazards.

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