IgE (Immunoglobulin E deficiency): Description, Causes and Risk Factors:
IgE is one of the 5 classes (isotypes) of antibodies. Like other immunoglobulins, it is produced by B cells and plasma cells. In contrast to other immunoglobulins, the circulating concentration of Immunoglobulin E deficiency is very low because B cells synthesize it at a very low rate and mast cells, basophils, and activated eosinophils bind up most of the circulating IgE. The normal concentration of IgE is only 0.05% of the IgG concentration.
Selective IgE deficiency is described as a concentration below 5 UI/mL or the definite absence of serum IgE without another immunological abnormality. Those patients do not manifest signs, but it can be associated with recurrent respiratory infections, chronic fatigue and musculoskeletal complications.
IgE role in acute hypersensitivity reactions and allergic diseases is well established; nevertheless, in immunological defense it is unclear: it is known that it does not cross the placenta or fixes the complement, but it is found in external secretions and binds to basophils and mast cells. Plasma cells producing Immunoglobulin E deficiency are located in mucous tissues of the respiratory and gastrointestinal tract and in the adenoid tissue; thus, the absence of this immunoglobulin results in a poor mucous defense with infection susceptibility.
IgE has a beneficial activity against parasitic infections (Schistosoma mansoni) after increasing their destruction by the macrophages; it also has antiviral and antibacterial activity and it might have an important role in some infections control, but in many scenarios, its serum concentration is too low to act as a neutralizing antibody, overall when there is a great antigenic burden, as this is the case of infections. Immunoglobulin E deficiency has alternate function in the immune defense, including acting as a cofactor to modify the microenvironment, due to its ability to release mast cell mediators which alter vascular permeability and to release the cell and humoral components in the site of infection, helping in an indirect way to clearance or elimination of pathogen agents.
IgE deficiency is difficult to define because normal IgE concentrations are so low. Immunoglobulin deficiency can be defined as IgE levels less than 2 U/mL in children and less than 4 U/mL in adults. Low Immunoglobulin E deficiency levels have been reported in severe combined immunodeficiency, hyper-IgM syndrome, ataxia telangiectasia, X-linked recessive Bruton agammaglobulinemia, and common variable immunodeficiency.
Certain pathogenic organisms are capable of simulating Immunoglobulin E deficiency production. The early immune response to Epstein-Barr virus (EBV) infection often includes a sharp rise in total serum IgE followed by rise in serum concentrations of other immunoglobulins classes and subclasses. Production of Immunoglobulin E deficiency specific antibody to respiratory syncytial virus (RSV) has been demonstrated in RSV-infected children, associated with an increased prevalence of wheezing. Characteristics of both the host and the pathogenic organism are likely to be important in determining the degree and class of antibody response to given infection, as well as clinical effect of the response. The effect of these antibodies on the course of disease may vary from one individual to another.
IgE is connected to hemoglobin (Hb) and Beta-2 microglobulin (B2M) levels. The researchers found that a high IgE meant a higher Hb and a lower B2M, and this in turn meant a better prognosis.
The patients with IgE deficiency may be associated with recurrent respiratory infections
, chronic fatigue and musculoskeletal complications. Low IgE levels can also occur as a sign of a rare inherited disease known as ataxia telangiectasia, which affects muscle coordination.
An immunoglobulins test is done to measure the level of immunoglobulins, also known as antibodies, in your blood. A low IgE can sometimes be seen when there are low levels of other antibodies, including the IgG or IgG subclasses, but researchers do not think it is regarded as a significant deficiency in its' own right. The amount of Immunoglobulin E deficiency antibodies in the blood is tiny comapred to the IgG and IgA antibodies that are more important in giving overall protection against infections.
There is no known cure. Promptly treat any infections with appropriate antibiotics. Dosage, route, and duration of therapy depend on the suspected pathogen, specific drug chosen, and response to therapy. Check the monograph of a particular antibiotic for detailed information concerning contraindications, drug interactions, and precautions.
IgE may be an important target in treatments for allergy and asthma. Currently, severe allergy and asthma is usually treated with drugs (like anti-histamines) that damp down the late stages of inflammation and relax airway smooth muscle. However, these treatments are fairly broad in their action, so many have unpleasant side-effects; they may also inhibit important protective responses.
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.