Immunoglobulin D (IgD), Serum
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Antibodies or immunoglobulins (Ig) are formed by plasma cells as a humoral immune response to antigens. The first antibodies formed after antigen stimulation are of the IgM class, followed later by IgG and also IgA antibodies. IgD normally occurs in serum in trace amounts.
Increased serum immunoglobulin concentrations occur due to polyclonal or oligoclonal immunoglobulin proliferation in hepatic diseases (chronic hepatitis, liver cirrhosis), acute and chronic infections, autoimmune diseases, as well as in the cord blood of neonates with intrauterine and perinatal infections. Increases in serum immunoglobulin concentration are seen in monoclonal gammopathies such as multiple myeloma, Waldenstrom's macroglobulinemia, primary amyloidosis, and monoclonal gammopathy of undetermined significance.
Decreased serum immunoglobulin concentrations occur in primary immunodeficiency conditions as well as in secondary immune insufficiencies including advanced monoclonal gammopathies, lymphatic leukemia, and advanced malignant tumors.
Quantitative determination of the immunoglobulins can provide important information on the humoral immune status.
Changes in IgD concentration are used as a marker of changes in the size of the clone of monoclonal IgD plasma cells.
The physiologic significance of serum IgD concentration is unclear and in many normal persons serum IgD is undetectable.
Increased concentrations may be due to polyclonal (reactive) or monoclonal plasma cell proliferative processes.
A monoclonal IgD protein is present in 1% of patients with myeloma. Monoclonal IgD proteins are often in low concentrations and do not have a quantifiable M-peak on serum protein electrophoresis. However, the presence of an IgD monoclonal protein is almost always indicative of a malignant plasma cell disorder such as multiple myeloma or primary amyloidosis.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
An elevated IgD cannot be taken as evidence for a monoclonal IgD protein. MPSS/81756 Monoclonal Protein Studies, Serum should be performed to distinguish between a polyclonal and monoclonal IgD.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
< or =10 mg/dL
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Blade J, Kyle RA: Immunoglobulin D multiple myeloma: Presenting features, response to therapy, and survival in a series of 53 cases. J Clin Oncol 1994;12(11):2398-2404
2. Kyle RA, Katzmann JA: Immunochemical characterization of immunoglobulins. In Manual of Clinical Laboratory Immunology. 5th edition. Edited by NR Rose, E Conway de Macario, JD Folds, et al: Washington, DC, ASM Press,1997, pp 156-176
3. Tietz NW: In Clinical Guide to Laboratory Tests. 2nd edition. Philadelphia, WB Saunders Company, 1990, p 325