To use all functions of this page, please activate cookies in your browser.
With an accout for my.bionity.com you can always see everything at a glance – and you can configure your own website and individual newsletter.
- My watch list
- My saved searches
- My saved topics
- My newsletter
Common variable immunodeficiency
Common variable immunodeficiency (CVID) is a group of 20-30 primary immunodeficiencies (PIDs) which have a common set of symptoms but with different underlying causes.
Causes and types
CVID is believed to be a genetically determined primary immune defect; however, the underlying causes are different. The result of these defects is that the patient doesn't produce sufficient antibodies in response to exposure to pathogens. As a result, the patient's immune system fails to protect them against common bacterial and viral (and occasionally parasitic and protozoan) infections. The net result is that the patient is susceptible to illness. Both parts of the immune system (the cellular and humoral system) are affected, hence its classification as a combined immunodeficiency.
CVID appears to include a number of defects, some of which have been identified. For the majority, the genetic causes are still unknown. It is possible that environmental agents provoke the immune defect, due to genetic predisposition, but this has not been clarified.
See also X-linked agammaglobulinemia, a similar disorder, better characterised than CVID. Hypogammaglobulinemia (CVID) and X-linked agammaglobulinemia (XLA) are often intermixed by physicians, as their clinical conditions and treatment are almost identical.
Symptoms of CVID are:
Diagnosis is often delayed; and diagnosis is often made in the second or third decade of life after referral to an immunologist.
As with several other immune cell disorders, CVID may predispose to lymphoma or possibly stomach cancer. There also appears to be a predilection for autoimmune diseases, with a risk of up to 25%. Autoimmune destruction of platelets or red blood cells are the commonest of these.
Treatment usually consists of immunoglobulin therapy, which is an injection of human antibodies harvested from blood donations: intravenous immunoglobulin (IVIG, most common treatment), subcutaneous immunoglobulin G (SCIG, relatively new therapy) or intramuscular immunglobulin (IMIG, less effective, painful). This is not a cure, but it strengthens immunity by ensuring that the patient has "normal" levels of antibodies, which helps to prevent recurrent upper respiratory infections. IG therapy can't be used if the patient has anti-IgA antibodies but in this case, products low in IgA can be used; subcutaneous delivery also is a means of permitting such patients to have adequate antibody replacement.
Some CVID patients may experience reactions to IG therapies; reactions may include:
Patients should not receive therapy if they are fighting an active infection as this increases the risk of reaction. Also, patients changing from one brand of product to another may be at higher risk of reaction for the first couple of treatments on the new brand.
Reactions can be minimised by taking an antihistamine and/or hydrocortisone and some paracetamol/acetaminophen/anti-inflammatory (naproxen, advil, aspirin) prior to treatment; patients should also be thoroughly hydrated and continue to drink water before, after and during treatment (if possible).
Research is currently focussing on genetic analysis, and in differentiating between the various different disorders in order to allow a cure to be developed. Cures are likely to be genetic in nature, repairing faulty genes and allowing the individual to start producing antibodies. Funding for research in the US is provided by the National Institutes of Health. Key research in the UK is funded by the Primary Immunodeficiency Association (PiA), and funding is raised through the annual Jeans for Genes campaign.
CVID has an estimated prevalence is about 1:25,000 to 1:50,000. The typical patient is between 20 and 40, and males and females are equally affected. About 20% of patients are diagnosed in childhood.
Janeway et al (1953) is generally credited with the description of the first case of CVID.
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Common_variable_immunodeficiency". A list of authors is available in Wikipedia.|