Immunoglobulin A, Quantitative, Serum
| Immunoglobulin A, Quantitative, Serum | | | |
| Number | | 001784 |
| CPT | | 82784 |
| Synonyms | | IgA, Serum ; Quantitative IgA, Serum |
| Test Includes | | Quantitation of IgA |
| Special Instructions | | Indicate patient's age on the request form. |
| Specimen | | Serum |
| Volume | | Pediatrics: 0.4 mL; adults: 1 mL |
| Container | | Red-top tube or gel-barrier tube |
| Storage Instructions | | Samples suspected of having macroglobulins or cryoglobulins should be drawn and held at 37°C. Samples suspected of containing cold agglutinins should not be refrigerated prior to serum separation from clot. |
| Patient Preparation | | Patient should be fasting. |
| Causes for Rejection | | Excessive lipemia |
| Reference Interval | | See table. IgA
Age
(y) | Range
(mg/dL) | | 0-1 | 0-83 | | 1-3 | 20-100 | | 4-6 | 27-195 | | 7-9 | 34-305 | | 10-11 | 53-204 | | 12-13 | 58-358 | | 14-15 | 47-249 | | 16-19 | 61-348 | | >19 | 70-400 |
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| Use | | Evaluate humoral immunity; monitor therapy in IgA myeloma |
| Limitations | | If samples containing macroglobulins, cryoglobulins, or cold agglutinins are handled at incorrect temperatures, false low values may result. |
| Methodology | | Immunologic |
| Additional Information | | Increased monoclonal IgA may be produced in lymphoproliferative disorders, especially multiple myeloma and “Mediterranean” lymphoma involving bowel. An IgA monoclonal peak >2 g/dL is a major criterion for myeloma. It may be elevated in a wide range of conditions affecting mucosal surfaces, where IgA is largely produced. Some clinically significant IgA deficiencies have concomitant deficiencies of IgG2 and IgG4. IgA may be decreased in patients with chronic sinopulmonary disease, in ataxia-telangiectasia, or congenitally. Patients with congenital IgA deficiency are prone to autoimmune diseases, and may develop antibody to IgA and anaphylaxis if transfused. IgA levels may rise with exercise and fall during pregnancy. |
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