Polyglandular Deficiency Syndromes

Definition

Polyglandular deficiency syndromes are disorders characterized by the failure of more than one endocrine gland to make hormones in sufficient quantities for the body to function normally.

Description

the endocrine system is a diverse group of glands located all over the body that work together to regulate the body's metabolic activities. It includes:

• the pituitary gland, located deep in the brain, is considered the "master gland" that regulates many of the others
• the thyroid gland is located in the neck and sets the metabolic speed of many processes,
• the parathyroid glands, attached to the back of the thyroid, regulate calcium balance,
• the adrenal glands are located on top of the kidneys and make four separate kinds of hormones,
• the gonads (sex organs) produce sex hormones,
• the pancreas is responsible for the production of digestive juices, insulin, and glucagon.

There are over a dozen different syndromes that involve failure of more than one endocrine gland.

Causes and symptoms

The cause of polyglandular deficiency syndromes is usually an autoimmune response—a condition in which the body generates antibodies to its own tissues. The immune system may attack one or more glands; however, because of their inter dependence, the destruction of one gland can often lead to the impairment of another. Other causes may include infectious disease; insufficient blood flow to the glands due to an obstruction such as a blood clot; or the presence of a tumor.

Doctors usually group polyglandular deficiency syndromes into three types:

• Type I occurs during childhood and is characterized by failure of the adrenals, parathyroids, thyroid, and gonads combined with hepatitis, hair loss, skin pigment changes, and inability of the bowel to absorb adequate nutrition. These children also get a persistent skin fungus infection called candidiasis.
• Type II occurs during adulthood and is characterized by failure of the adrenals, thyroid (Schmidt's syndrome), and gonads combined with similar nutritional failures and hair and skin changes. These patients also have myasthenia gravis. This type of polyglandular deficiency syndrome often produces insulin-dependent diabetes mellitus (IDDM).
• Type III disease may produce diabetes or adrenal failure combined with thyroid problems. It may also include baldness (alopecia ), anemia, and vitiligo (condition characterized by white patches on normally pigmented skin).

Not all symptoms of any syndrome appear at once or in the same patient.

Diagnosis

Because these diseases evolve over time, the final diagnosis may not appear for years. A family history is very helpful in knowing what to expect. Any single endocrine abnormality should heighten suspicion that there are others, since they so often occur together, both as underproduction and overproduction of hormones. Most hormone levels can be monitored through blood tests. Many of the antibodies that characterize these conditions can also be found by blood testing.

Treatment

Fortunately there are replacements available for all the missing hormones. Careful balancing of them all can provide a reasonably comfortable quality of life for these patients.

Resources

BOOKS

Sherman, Steven I., and Robert F. Gagel. "Disorders Affecting Multiple Endocrine Systems." In Harrison's Principles of Internal Medicine, edited by Anthony S. Fauci, et al. New York: McGraw-Hill, 1997.

KEY TERMS

Antibody— A weapon in the body's immune defense arsenal that attacks a specific antigen.

Congenital— Present at birth.

Myasthenia gravis— A disease that causes muscle weakness.

Rubella— German measles.

Syndrome— A collection of abnormalities that occur often enough to suggest they have a common cause.