A disorder caused by an inherited flaw in the immune system that increases the susceptibility to infections. Primary immunodeficiency diseases are unlike secondary or acquired immune deficiency diseases, which are caused by infectious, chemical or radiological agents. AIDS is a prototype of an acquired immune deficiency disease.
It has been estimated that there are 100 different primary immunodeficiency diseases. All are genetic conditions in which specific cells of the immune system do not function properly. Clinical symptoms range from mild or nonexistent as in the case of selective IgA deficiency to severe symptoms as in the case of severe combined immunodeficiency (SCID), commonly referred to as “bubble-boy” syndrome.
Although the susceptibility to infections is a major consequence of the primary immunodeficiency diseases, they may cause other health problems as well, including allergies, asthma, swollen joints, digestive tract problems, growth problems or an enlarged liver and spleen. Many people with primary immune deficiency diseases require treatment which may include intravenous gamma globulin infusions, antibiotic therapies, or bone marrow transplantation.
The primary immune deficiency disorders range in frequency. Some disorders such as selective IgA deficiency are quite common, occurring as often as 1/500 to 1/1000 individuals. Others disorders such as SCID are rare affecting perhaps one person per million. Approximately 25,000 to 50,000 Americans are severely affected by primary immune deficiency disorders.
- Primary liver cancer, adult
A tumor in which the cancer starts during adulthood in cells in the liver. Also called hepatocellular carcinoma. Primary liver cancer is different from cancer that has metastasized (spread) from another place in the body to the liver. The signs and symptoms may include a hard lump just below the rib cage on the right […]
- Primary progressive aphasia
An atypical dementia characterized by a relentless dissolution of language with memory relatively preserved. The diagnosis of primary progressive aphasia is based on the presence of a progressive disorder of language, with preservation of other mental functions and of activities of daily living, for at least two years. The features of primary progressive aphasia are […]
- Primary sclerosing cholangitis
A chronic disorder of the liver of uncertain cause in which the bile ducts within and outside of the liver become inflamed, thickened, scarred (sclerotic), and obstructed. This progressive process can in time destroy the bile ducts and lead to cirrhosis. Abbreviated PSC. PSC can occur by itself or in association with other diseases, including […]
- Primary teeth
The first teeth which are shed and replaced by permanent teeth. The first primary tooth comes in at about 6 months of age and the 20th and last primary tooth erupts at around 2 1/2 years of age. The primary teeth are replaced beginning usually at about age 6. Also called baby teeth, milk teeth, […]
- Primary tumor
A tumor that is at the original site where it first arose. For example, a primary brain tumor is one that arose in the brain as opposed to one that arose elsewhere and metastasized (spread) to the brain. The original tumor is sometimes called “the primary.”