Hypergammaglobulinemia

Hypergammaglobulinemia

Infobox_Disease
Name = PAGENAME


Caption =
DiseasesDB =
ICD10 = ICD10|D|89|0|d|80, ICD10|D|89|2|d|80
ICD9 = ICD9|289.89
ICDO =
OMIM =
MedlinePlus =
eMedicineSubj =
eMedicineTopic =
MeshID = D006942

Hypergammaglobulinemia is a medical condition with elevated levels of gamma globulin.

It is a type of immunoproliferative disorder.

Types

Hypergammaglobulinemia is a condition that is characterized by the increased levels of a certain immunoglobulin in the blood serum.Health Communication Network. Immunoproliferative disorders- Topic Tree. http://www.use.hcn.com.au/subject.%60Immunoproliferative%20Disorders%60/home.html. Accessed March 2007.] The name of the disorder refers to the position of the excess of proteins after serum protein electrophoresis (found in the gammaglobulin region). Most hypergammaglobulinemias are caused by an excess of immunoglobulin M (IgM), because this is the default immunoglobulin type prior to class switching. Some types or hypergammaglobulinemia are actually caused by a deficiency in the other major types of immunoglobulins, which are IgA, IgE and IgG. There are 5 types of hypergammaglobulinemias associated with hyper IgM.OMIM|308230|Immunodeficiency with hyper IgM]

Type 1

X-linked immunodeficiency with hyper–immunoglobulin M, which is also called type 1 hyper IgM, is a rare form of primary immunodeficiency disease caused by a mutation in the Tumor Necrosis Factor Super Family member 5 (TNFSF5) gene, which codes for CD40 ligand. This gene is located on the long arm of the X chromosome at position 26, denoted Xq26.eMedicine|ped|2457|Park LC X-linked Immunodeficiency with hyper IgM] Normally, CD40 ligand is expressed on activated T cells, and is necessary to induce immunoglobulin class switching from IgM to the other immunoglobulin types. It does this by binding to its ligand, CD40, which is found expressed on the surface of B cells.cite book |author=Lichtman, Andrew H.; Abbas, Abul K. |title=Cellular and molecular immunology |publisher=Saunders |location=Philadelphia |year=2003 |pages= |edition=5th ed. |isbn=0-7216-0008-5 |oclc= |doi= |accessdate=] The mutation in the TNFSF5 gene causes there to be no recognition of CD40 by CD40 ligand, and thus the T cells do not induce Ig class switching in B cells, so there are markedly reduced levels of IgG, IgA, and IgE, but have normal or elevated levels of IgM. CD40 ligand is also required in the functional maturation of T lymphocytes and macrophages, so patients with this disorder have a variable defect in T-lymphocyte and macrophage effector function, as well as hyper IgM. ]

Type 2

Immunodeficiency with hyper IgM type 2 is caused by a mutation in the Activation-Induced Cysteine Deaminase (AICDA) gene, which is located on the short arm of chromosome 12. The protein that is encoded by this gene is called Activation-Induced Cysteine Deaminase (AICDA) and functions as an RNA-editing deaminase that induces somatic hypermutation, class switch recombination, and immunoglobulin gene conversion in B cells.cite journal |author=Noguchi E, Shibasaki M, Inudou M, "et al" |title=Association between a new polymorphism in the activation-induced cytidine deaminase gene and atopic asthma and the regulation of total serum IgE levels |journal=J. Allergy Clin. Immunol. |volume=108 |issue=3 |pages=382–6 |year=2001 |pmid=11544457 |doi=10.1067/mai.2001.117456 |url=http://linkinghub.elsevier.com/retrieve/pii/S0091-6749(01)01611-6] When a person is homozygous for the mutation in the AICDA gene, the protein fails to function, and thus somatic hypermutation, class switch recombination, and immunoglobulin gene conversion cannot occur, which creates an excess of IgM.

Type 3

Immunodeficiency with hyper IgM type 3 is caused by a mutation in the gene that codes for CD40. As mentioned above, CD40 is expressed on the surface of B cells, and its binding to CD40 ligand on activated T cells induces Ig class switching. ] When the mutation is present, there is no signal for B cells to undergo class switching, so there is an excess of IgM and little to no other immunoglobulin types produced.

Type 4

Immunodeficiency with hyper IgM type 4 is poorly characterized. All that is known is that there is an excess of IgM in the blood, with normal levels of the other immunoglobulins. The exact cause is yet to be determine.

Type 5

Immunodeficiency with hyper IgM type 5 is caused by a mutation in the Uracil DNA Glycosylase (UNG) gene, which, like AICDA, is located on chromosome 12. This codes for Uracil DNA Glycosylase, which is responsible for excising previous uracil bases that are due to cytosine deamination, or previous uracil misincorporation from double-stranded previous DNA substrates. This enzyme is also responsible for helping with gene conversion during somatic recombination in B cells. The mutation in the gene causes an enzyme that does not function properly, thus gene conversion does not proceed and class switching cannot occur.

ee also

* Monoclonal gammopathy of undetermined significance

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • hypergammaglobulinemia — An increased amount of the γ globulins in the plasma, such as that frequently observed in chronic infectious diseases. * * * hy·per·gam·ma·glob·u·lin·emia or chiefly Brit hy·per·gam·ma·glob·u·lin·ae·mia .hī pər .gam ə .gläb yə lə nē mē ə n the… …   Medical dictionary

  • polyclonal hypergammaglobulinemia — hypergammaglobulinemia due to increased quantity of all immunoglobulin classes, rather than only one …   Medical dictionary

  • Immunoproliferative disorders — (also known as “immunoproliferative diseases” or “immunoproliferative neoplasms”) are disorders of the immune system that are characterized by the abnormal proliferation of the primary cells of the immune system, which includes B cells, T cells… …   Wikipedia

  • Gamma globulin — Gamma globulins, or Ig s, are a class of proteins in the blood, identified by their position after serum protein electrophoresis. The most significant gamma globulins are immunoglobulins.InjectionsGamma globulin injections are usually given in an …   Wikipedia

  • Multiple myeloma — Classification and external resources Micrograph of a plasmacytoma, the histologic correlate of multiple myeloma. H E stain ICD …   Wikipedia

  • HIV test — Randall L. Tobias, former U.S. Global AIDS Coordinator, being publicly tested for HIV in Ethiopia in an effort to reduce the stigma of being tested.[1] HIV tests are used to detect the presence of the human immunodeficiency virus (HIV), the virus …   Wikipedia

  • POEMS syndrome — Classification and external resources DiseasesDB 29226 eMedicine derm/771 …   Wikipedia

  • List of AIDS-related topics — This is a list of AIDS related topics, many of which were originally taken from the public domain U.S. Department of Health Glossary of HIV/AIDS Related Terms, 4th Edition. [http://www.aidsinfo.nih.gov/ed resources/glossary/] NOTOC A AACTG… …   Wikipedia

  • Cryoglobulinemia — Classification and external resources ICD 10 D89.1 ICD 9 273.2 …   Wikipedia

  • Monoclonal gammopathy of undetermined significance — Classification and external resources Schematic representation of a normal protein electrophoresis gel. A small spike would be present in the gamma (γ) band in MGUS ICD 1 …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”