Immunoglobulin D Blood Test: Basic Facts

Immunoglobulin D blood test is also called IgD blood test.

Immunoglobulins (Igs) are a category of proteins produced by immune cells that aid in bodily defense against outside invaders. They recognize characteristic surface markings (antigens) on a foreign object and bind them away, before any damage is done to the body.

There are 5 five main types of immunoglobulins; each type, differing in its function and distribution throughout the body. The 5 types are:

  • IgA
  • IgG
  • IgE
  • IgD
  • IgM

Immunoglobulins can reside either on the outside of cells, or freely circulate in blood. When circulating, they are also called antibodies (Abs).

There are 3 categories of antibodies:

  • Circulating antibody: These antibodies circulate in blood and look for infection

Tissue antibody: These antibodies are present in tissues or organs all over the body and fights infections in the body.

  • Secretory antibody: These antibodies are secreted in body fluids, such as saliva and mucus, and help prevent infection coming into the body from exposed mucus surface.
  • Plasma cells serve as antibody factories. They are specialized immune cells that, when stimulated by the immune system can produce and secrete up to 100 million antibodies per hour.

Immunoglobulin D (IgD) is mostly found on the surface of special immune cells called B-cells (type of lymphocytes), where it helps regulate B-cell function. IgD also activates certain immune cells. The function of IgD that circulates in the bloodstream is unknown.

The Immunoglobulin D Blood Test helps determine the level of IgD in blood. It helps diagnose myelomas and immune deficiencies. An increased level of IgD is associated with many diseases and disorders.


What are the Clinical Indications for performing the Immunoglobulin D Blood Test?

Following are the clinical indications for performing the Immunoglobulin D Blood Test:

  • Monitoring myelomas and immune disorder
  • Monitoring therapy for myelomas
  • Loss of appetite
  • Pain
  • Fatigue
  • Vulnerability to infections: Individuals with decreased immune system are at an increased risk for infections


What is the Significance of the Immunoglobulin D Blood Test Result?

The significance of the Immunoglobulin D Blood Test result is explained.

A high value (greater than 15.3 mg/dL) for the test may indicate:

  • Multiple myeloma
  • Monoclonal gammopathy of unknown significance (MGUS)
  • Chronic infection
  • Autoimmune disease
  • Acute viral hepatitis
  • Chronic obstructive pulmonary disease

A low value for the test may indicate:

  • Hereditary deficiencies
  • Acquired immunodeficiency
  • Non-IgD myeloma

The laboratory test results are NOT to be interpreted as results of a “stand-alone” test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.


Additional and Relevant Useful Information

Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.


Keyword: immunoglobulin D blood test.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.