Hypergammaglobulinemia pathophysiology
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Soujanya Thummathati, MBBS [2]
Overview
Hypergammaglobulinemia is an immunoproliferative disorder with elevated levels of gamma globulin (immunoglobulins or antibodies).[1][2]
Pathophysiology
- Hypergammaglobulinemia is an immunoproliferative disorder which arises from B cells, which are a type of white cells that are normally involved in the development of humoral immunity by secreting antibodies.[3]
- The majority of the hypergammaglobulinemias are caused by an excess of immunoglobulin M (IgM) because this is the default immunoglobulin type prior to class switching.[1]
- Hypergammaglobulinemias may also be caused by a deficiency in the other major types of immunoglobulins.[1][4]
- The term "hypergammaglobulinemia" refers to the position of the excess of proteins after serum protein electrophoresis (found in the gammaglobulin region).[1]
Normal Mechanism of Immunoglobulin Class Switching
- Immunoglobulin class switching, also known as isotype switching, isotypic commutation or class-switch recombination (CSR), is a biological mechanism that changes a B cell's production of immunoglobulins (antibodies) from one type to another, such as from the isotype IgM to the isotype IgG.
- Naïve mature B cells produce both IgM and IgD, which are the first two heavy chain segments in the immunoglobulin locus.
- After activation by the antigen, the B cells proliferate. If these activated B cells encounter specific signaling molecules via their CD40 and cytokine receptors (both modulated by T helper cells), they undergo antibody class switching to produce IgG, IgA or IgE antibodies.
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![Mechanism of class-switch recombination that allows isotype switching in activated B cells[5]](/images/b/b3/Class_switch_recombination.png)
Mechanism of class-switch recombination that allows isotype switching in activated B cells[5]
![Mechanism of class-switch recombination that allows isotype switching in activated B cells[5]](/index.php/File:Class_switch_recombination.png)
Type 1 hypergammaglobulinemia
- The tumor necrosis factor super family member 5 (TNFSF5) gene mutation is involved in the pathogenesis of type 1 hypergammaglobulinemia.
- Type 1 hypergammaglobulinemia is transmitted in x-linked recessive pattern.
mutation in the Tumor Necrosis Factor Super Family member 5 (TNFSF5) gene, which codes for CD40 ligand
References
- ↑ 1.0 1.1 1.2 1.3 Hypergammaglobulinemia. Wikipedia. https://en.wikipedia.org/wiki/Hypergammaglobulinemia Accessed on February 24, 2016.
- ↑ Globulin. Wikipedia. https://en.wikipedia.org/wiki/Globulin. Wikipedia. Accessed on February 24, 2016.
- ↑ B cell. Wikipedia. https://en.wikipedia.org/wiki/B_cell Accessed on February 24, 2016.
- ↑ Immunoproliferative disorder. Wikipedia. Accessed on February 24, 2016.
- ↑ Immunoglobulin class switching. Wikipedia. https://en.wikipedia.org/wiki/Immunoglobulin_class_switching. AccessedonFebruary 29, 2016.