Immunoglobulin class

Immunoglobulins are complex proteins that are involved in protecting the body from pathogenic microbes and viruses. They belong to the class of globulin fraction proteins and have the ability to bind foreign antigens. Immunoglobulin formation is one of the most important functions of the immune system, performed by its plasma cells.

Of primary importance for immunology are four classes of immunoglobuins, designated by the letters G, A, M, D. The immunoglobulin classes M (IgM) and G (lgG) are also called “slow” and “fast” classes, respectively, for their fast half-life from the blood. Their ratio is about 80% IgM and 20% IgG, corresponding to 30 percent of the total circulating immunoglobulin population. The IgG and IgA classes are present in blood serum in significantly larger quantities than IgM. Their characteristic half-life is 19 days and 3-4 days. Thus, the concentration of each class changes in a strictly defined direction. An increase in the level of immunoglobulin is characterized by primary or secondary immunodeficiency, some forms of thyroid pathology and some infections. A decrease in immunoglobin levels is only rarely recorded in medical practice. Normally, between the concentration of the immunoglobule, an increase in the concentration of low-agglutinogenic classes and a reduction in more agglutinogenic classes contributes, and in some conditions and diseases the opposite dynamics are observed. The amount of immunoglobulin is usually considered the main marker for assessing the strength of humoral immunity. Specific antibodies, by definition, are involved in protective reactions, and achieving a positive titer of binding antibodies is considered a criterion for intense immunity. However, it must be taken into account that determining the level of antibodies only in a quantitative aspect does not make it possible to assess the stage and nature of the disease. In many conditions, an increase in the level of reagin can be paradoxical and pathological, depending on the localization of antibodies in the body and their functional status, the presence of cross-reaction and the production of normal immunoglobulins of other isotypes.

Immunoglobulins are a large group of proteins synthesized by plasma cells and serving as the body's main protective antibodies. They are part of the body's complex defense system against infection. Each type of immunoglobulin has a unique structure, specificity for certain antigens and can be used to neutralize them.

Immunoglobulin is a glycoprotein that consists of two heavy (H) and two light (L) polypeptide strands separated by a disulfide bond between the C-terminus of the heavy chain and the N-terminus of the light chain. The heavy chain contains several Ig-binding regions, called domains or hinges, which are involved in binding and connecting various components of the immune system. There are five classes of immunoglobulin glimbins.