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Hypergammaglobulinaemia
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 an 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 of 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. MeSH considers hyper IgM syndrome to be a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Globulin
Gamma globulins are a class of globulins, identified by their position after serum protein electrophoresis. The most significant gamma globulins are immunoglobulins ( antibodies), although some immunoglobulins are not gamma globulins, and some gamma globulins are not immunoglobulins. Use as medical treatment Gamma globulin injections are usually given in an attempt to temporarily boost a patient's immunity against disease. Injections are most commonly used on patients having been exposed to hepatitis A or measles, or to make a kidney donor and a recipient compatible regardless of blood type or tissue match. Injections are also used to boost immunity in patients unable to produce gamma globulins naturally because of an immune deficiency, such as X-linked agammaglobulinemia and hyper IgM syndrome. Such injections are less common in modern medical practice than they were previously, and injections of gamma globulin previously recommended for travelers have largely been replaced b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunoproliferative Disorder
Immunoproliferative disorders 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 and natural killer (NK) cells, or by the excessive production of immunoglobulins (also known as antibodies). Classes These disorders are subdivided into three main classes, which are lymphoproliferative disorders, hypergammaglobulinemia, and paraproteinemia.Health Communication Network. Immunoproliferative disorders - Topic Tree. http://www.use.hcn.com.au/subject.%60Immunoproliferative%20Disorders%60/home.html. Accessed March 2007. The first is cellular, and the other two are humoral (however, humoral excess can be secondary to cellular excess.) * ''Lymphoproliferative disorders'' (LPDs) refer to several conditions in which lymphocytes are produced in excessive quantities. They typically occur in patients who have compromised immune systems. This subset is sometimes incorrectly equated with "i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunoglobulin G
Immunoglobulin G (Ig G) is a type of antibody. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. Each IgG antibody has two paratopes. Function Antibodies are major components of humoral immunity. IgG is the main type of antibody found in blood and extracellular fluid, allowing it to control infection of body tissues. By binding many kinds of pathogens such as viruses, bacteria, and fungi, IgG protects the body from infection. It does this through several mechanisms: * IgG-mediated binding of pathogens causes their immobilization and binding together via agglutination; IgG coating of pathogen surfaces (known as opsonization) allows their recognition and ingestion by phagocytic immune cells leading to the elimination of the pathogen itself; * IgG activates all the classical pathway of the complement system, a cascade of immune protein pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Subject Headings
Medical Subject Headings (MeSH) is a comprehensive controlled vocabulary for the purpose of indexing journal articles and books in the life sciences. It serves as a thesaurus that facilitates searching. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed article database and by NLM's catalog of book holdings. MeSH is also used by ClinicalTrials.gov registry to classify which diseases are studied by trials registered in ClinicalTrials. MeSH was introduced in the 1960s, with the NLM's own index catalogue and the subject headings of the Quarterly Cumulative Index Medicus (1940 edition) as precursors. The yearly printed version of MeSH was discontinued in 2007; MeSH is now available only online. It can be browsed and downloaded free of charge through PubMed. Originally in English, MeSH has been translated into numerous other languages and allows retrieval of documents from different origins. Structure MeSH vocabulary is divi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyper IgM Syndrome
Hyper IgM syndrome describes a group of primary immune deficiency disorders characterized by defective CD40 signaling; ''via'' B cells affecting class switch recombination (CSR) and somatic hypermutation. Immunoglobulin (Ig) class switch recombination deficiencies are characterized by elevated serum Immunoglobulin M (IgM) levels and a considerable deficiency in Immunoglobulins G (IgG), A (IgA) and E (IgE). As a consequence, people with HIGM have decreased concentrations of serum IgG and IgA and normal or elevated IgM, leading to increased susceptibility to infections.update 2013 Signs and symptoms Among the presentation consistent with hyper IgM syndrome are the following: * Infection/ ''Pneumocystis'' pneumonia (PCP), which is common in infants with hyper IgM syndrome, is a serious illness. PCP is one of the most frequent and severe opportunistic infections in people with weakened immune systems. Many CD40 Ligand Deficiency are first diagnosed after having PCP in their fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysgammaglobulinemia
Dysgammaglobulinemia is a type of immune disorder characterized by a reduction in some types of gamma globulins, resulting in heightened susceptibility to some infectious diseases where primary immunity is antibody based. It is distinguished from hypogammaglobulinemia, which is a reduction in ''all'' types of gamma globulins. Hyper IgM syndrome can be considered a form of dysgammaglobulinemia, because it results from a failure of transformation from IgM production to production of other antibodies, and so the condition can be interpreted as a reduction of the other types. See also *Immunodeficiency Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that a ... References Further reading * Raif S. Geha et al.:Hyper Immunoglobulin M Immunodeficiency (Dysgammaglobulinemia), ''Journal of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TNFSF5
CD154, also called CD40 ligand or CD40L, is a protein that is primarily expressed on activated T cells and is a member of the TNF superfamily of molecules. It binds to CD40 on antigen-presenting cells (APC), which leads to many effects depending on the target cell type. In total CD40L has three binding partners: CD40, α5β1 integrin and αIIbβ3. CD154 acts as a costimulatory molecule and is particularly important on a subset of T cells called T follicular helper cells (TFH cells). On TFH cells, CD154 promotes B cell maturation and function by engaging CD40 on the B cell surface and therefore facilitating cell-cell communication. A defect in this gene results in an inability to undergo immunoglobulin class switching and is associated with hyper IgM syndrome. Absence of CD154 also stops the formation of germinal centers and therefore prohibiting antibody affinity maturation, an important process in the adaptive immune system. History In 1991, three groups reported di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AICDA
Activation-induced cytidine deaminase, also known as AICDA, AID and single-stranded DNA cytosine deaminase, is a 24 kDa enzyme which in humans is encoded by the ''AICDA'' gene. It creates mutations in DNA by deamination of cytosine base, which turns it into uracil (which is recognized as a thymine). In other words, it changes a C:G base pair into a U:G mismatch. The cell's DNA replication machinery recognizes the U as a T, and hence C:G is converted to a T:A base pair. During germinal center development of B lymphocytes, AID also generates other types of mutations, such as C:G to A:T. The mechanism by which these other mutations are created is not well understood. It is a member of the APOBEC family. In B cells in the lymph nodes, AID causes mutations that produce antibody diversity, but that same mutation process leads to B cell lymphoma. Function This gene encodes a DNA-editing deaminase that is a member of the cytidine deaminase family. The protein is involv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD40
Cluster of differentiation 40, CD40 is a costimulatory protein found on antigen-presenting cells and is required for their activation. The binding of CD154 (CD40L) on T helper cell, TH cells to CD40 activates antigen presenting cells and induces a variety of downstream effects. Deficiency can cause Hyper-IgM syndrome type 3. Function The protein receptor encoded by this gene is a member of the TNF-receptor superfamily. This receptor has been found to be essential in mediating a broad variety of immune and inflammatory responses including T cell-dependent immunoglobulin class switching, memory B cell development, and germinal center formation. AT-hook transcription factor AKNA is reported to coordinately regulate the expression of this receptor and its ligand, which may be important for homotypic cell interactions. The interaction of this receptor and its ligand is found to be necessary for amyloid-beta-induced microglial activation, and thus is thought to be an early event in Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ig 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 immunoglobulin from one type to another, such as from the isotype IgM to the isotype IgG. During this process, the constant-region portion of the antibody heavy chain is changed, but the variable region of the heavy chain stays the same (the terms ''variable'' and ''constant'' refer to changes or lack thereof between antibodies that target different epitopes). Since the variable region does not change, class switching does not affect antigen specificity. Instead, the antibody retains affinity for the same antigens, but can interact with different effector molecules. Mechanism Class switching occurs after activation of a mature B cell via its membrane-bound antibody molecule (or B cell receptor) to generate the different classes of antibody, all with the same variable domains as the original a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uracil-DNA Glycosylase
Uracil-DNA glycosylase is also known as UNG or UDG. Its most important function is to prevent mutagenesis by eliminating uracil from DNA molecules by cleaving the N-glycosidic bond and initiating the base-excision repair (BER) pathway. Function The human gene encodes one of several uracil-DNA glycosylases. Alternative promoter usage and splicing of this gene leads to two different isoforms: the mitochondrial UNG1 and the nuclear UNG2. One important function of uracil-DNA glycosylases is to prevent mutagenesis by eliminating uracil from DNA molecules by cleaving the N-glycosidic bond and initiating the base-excision repair (BER) pathway. Uracil bases occur from cytosine deamination or misincorporation of dUMP residues. After a mutation occurs, the mutagenic threat of uracil propagates through any subsequent DNA replication steps. Once unzipped, mismatched guanine and uracil pairs are separated, and DNA polymerase inserts complementary bases to form a guanine-cytosine (GC) pair in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoclonal Gammopathy Of Undetermined Significance
Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell dyscrasia in which plasma cells or other types of antibody-producing cells secrete a myeloma protein, i.e. an abnormal antibody, into the blood; this abnormal protein is usually found during standard laboratory blood or urine tests. MGUS resembles multiple myeloma and similar diseases, but the levels of antibodies are lower, the number of plasma cells (white blood cells that secrete antibodies) in the bone marrow is lower, and it rarely has symptoms or major problems. However, since MGUS can lead to multiple myeloma, which develops at the rate of about 1.5% a year, or other symptomatic conditions, yearly monitoring is recommended. The progression from MGUS to multiple myeloma usually involves several steps. In rare cases, it may also be related with a slowly progressive symmetric distal sensorimotor neuropathy. Signs and symptoms People with monoclonal gammopathy generally do not experience signs or sympto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
