Lab Test

Immunoglobulin A (IgA)

IgA, Immunoglobulin A, Serum

Test Codes

Antrim #30425, EPIC: LAB5787, IGA



Specimen Collection Criteria

Collect: One Gold-top SST tube. (Minimum Whole Blood: 4.0 mL)

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then immediately centrifuge to separate serum from cells. Refrigerate (2-8°C or 36-46°F) the centrifuged collection tube within 12 hours of collection. (Minimum Serum: 0.5 mL)

Preparation for Courier Transport

Transport: Centrifuged collection tube, refrigerated (2-8°C or 36-46°F). (Minimum Serum: 0.5 mL)

Rejection Criteria

  • Grossly lipemic specimens.
  • Hemolyzed specimens.
  • Plasma specimens.

In-Lab Processing

Let specimen clot 30-60 minutes then immediately centrifuge to separate serum from cells. Room temperature is acceptable for a maximum of 12 hours. (Minimum Serum: 0.5 mL)


Specimen Stability for Testing:

Centrifuged SST tubes, Red-top tubes, and Microtainers®
Room Temperature (20-26°C or 68-78.8°F): 12 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Serum Specimens (Pour-Overs)
Room Temperature (20-26°C or 68-78.8°F): 12 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 3 months

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days


Dearborn Chemistry Laboratory
Royal Oak Automated Chemistry Laboratory


Sunday – Saturday.
Results available within 24 hours of receipt in the Laboratory.

Reference Range

 Current Royal Oak and Troy
0-29 Days: 8-29 mg/dL  <1 Year 0-30 mg/dL.
1-3 Months: 8-29 mg/dL  1-2 Years 0-90 mg/dL.
4-6 Months: 10-47 mg/dL  3-5 Years 30-150 mg/dL.
7-12 Months: 15-58 mg/dL  6-13 Years 50-220 mg/dL.
13-24 Months: 20-88 mg/dL  14-18 Years 50-209 mg/dL.
25-36 Months: 22-78 mg/dL Adult 70-365 mg/dL.
3-5 Years: 29-138 mg/dL    
6-8 Years: 61-201 mg/dL    
9-11 Years: 57-251 mg/dL    
12-16 Years: 57-190 mg/dL    
Adult Range: 88-374 mg/dL    

Methodology: Immunoturbidimetric

Test Methodology



Decreased IgA levels are associated with selective hypo-IgA, protein-losing enteropathies, hereditary ataxia telangiectasia, and nephrotic syndrome.

Increased IgA levels are associated with infectious diseases, rheumatoid arthritis, polyclonal gammopathies, monocytic leukemia, IgA myeloma, and liver disease.

Half Life in Blood: 6 days.

Clinical Utility

IgA levels are used to evaluate humoral immunity and to aid in the diagnosis of conditions associated with IgA excess or depression. IgA represents 15-20% of the total circulating immunoglobulin pool. It is the predominant immunoglobulin in secretions such as tears, saliva, colostrum, milk, and intestinal secretions.

Clinical Disease

Selective IgA deficiency is a primary immunodeficiency disorder characterized by reduced production of IgA with recurrent respiratory and gastrointestinal infections. Selective IgA deficiency can result from congenital intrauterine infection with rubella virus, Toxoplasma gondii, or cytomegalovirus. A transient IgA deficiency may result following the treatment with penicillamine of Wilson's disease. Most patients with selective IgA deficiencies are asymptomatic. Symptomatic patients usually present with recurrent ear infections, sinusitis, pneumonia, diarrhea, asthma, autoimmune diseases and/or allergies. Administration of blood products containing IgA can cause some IgA deficient patients to develop antibodies against IgA. If an anti-IgA antibody develops, a massive allergic reaction can result during blood or plasma transfusions.

CPT Codes

LOINC: 2458-8


Last Updated


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