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HelpTest ID: IGA Immunoglobulin A (IgA), Serum
Reporting Name
Immunoglobulin A (IgA), SUseful For
Detection or monitoring of IgA monoclonal gammopathies and IgA-related immune deficiencies
Testing Algorithm
The following algorithms are available:
-Celiac Disease Comprehensive Cascade Test Algorithm
-Celiac Disease Diagnostic Testing Algorithm
-Celiac Disease Gluten-Free Cascade Test Algorithm
Specimen Type
SerumOrdering Guidance
Cascade testing is recommended for celiac disease. Cascade testing ensures that testing proceeds in an algorithmic fashion. The following cascades are available; select the appropriate one for your specific patient situation.
-CDCOM / Celiac Disease Comprehensive Cascade, Serum and Whole Blood: Complete testing including HLA DQ
-CDSP / Celiac Disease Serology Cascade, Serum: Complete serology testing excluding HLA DQ
-CDGF / Celiac Disease Gluten-Free Cascade, Serum and Whole Blood: For patients already adhering to a gluten-free diet
To order individual tests, see Celiac Disease Diagnostic Testing Algorithm.
Specimen Required
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 28 days | |
| Frozen | 28 days | ||
| Ambient | 14 days |
Special Instructions
Reference Values
0-<5 months: 7-37 mg/dL
5-<9 months: 16-50 mg/dL
9-<15 months: 27-66 mg/dL
15-<24 months: 36-79 mg/dL
2-<4 years: 27-246 mg/dL
4-<7 years: 29-256 mg/dL
7-<10 years: 34-274 mg/dL
10-<13 years: 42-295 mg/dL
13-<16 years: 52-319 mg/dL
16-<18 years: 60-337 mg/dL
≥18 years: 61-356 mg/dL
Day(s) Performed
Monday through Friday
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
82784
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| IGA | Immunoglobulin A (IgA), S | 2458-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| IGA | Immunoglobulin A (IgA), S | 2458-8 |
Clinical Information
The gamma globulin band as seen in conventional serum protein electrophoresis consists of 5 immunoglobulins. In normal serum, about 15% is IgA.
Monoclonal gammopathies of all types may lead to a spike in the gamma globulin zone seen on serum protein electrophoresis.
Monoclonal elevations of IgA characterize multiple myeloma.
Decreased immunoglobulin levels are found in patients with congenital deficiencies.
Interpretation
Increased serum immunoglobulin concentrations occur due to polyclonal or oligoclonal immunoglobulin proliferation in hepatic disease (hepatitis, liver cirrhosis), connective tissue diseases, acute and chronic infections, as well as in the cord blood of neonates with intrauterine and perinatal infections.
Elevation of IgA may occur in monoclonal gammopathies such as multiple myeloma, primary systemic amyloidosis, monoclonal gammopathy of undetermined significance, and related disorders.
Decreased levels are found in patients with primary or secondary immune deficiencies.
Clinical Reference
1. Webster ADB: Laboratory investigation of primary deficiency of the lymphoid system. In: Clinics in Immunology and Allergy. Vol 5. 3rd ed. WB Saunders Company; 1985:447-468
2. Pinching AJ: Laboratory investigation of secondary immunodeficiency. In: Clinics in Immunology and Allergy. Vol 5. 3rd ed. WB Saunders Company; 1985:469-490
3. Dispenzieri A, Gertz MA, Kyle RA: Distribution of diseases associated with moderate polyclonal gammopathy in patients seen at Mayo Clinic during 1991. Blood. 1997;90:353A
4. Kyle RA, Greipp PR: The laboratory investigation of monoclonal gammopathies. Mayo Clin Proc. 1978 Nov;53(11):719-739
5. Ballow M, O'Neil KM: Approach to the patient with recurrent infections. In: Middleton Jr E, Reed CE, Ellis, et al. Allergy: Principles and Practice. Vol 2. 4th ed. Mosby-Year Book, Inc; 1993:1027-1058
6. Kyle RA: Detection of quantitation of monoclonal proteins. Clin Immunol Newsletter. 1990 June;10(6):84-86
7. Dietzen DJ, Willrich MAV: Amino acids, peptides, and proteins. In: Rifai N, Chiu RWK, Young I, Burnham CAD, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 31
Report Available
1 to 3 daysMethod Name
Nephelometry
Forms
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.
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