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Test Code LAB73 Immunoglobulin A (IgA), Blood

Performing Laboratory

St. Louis Children's Hospital Laboratory - Chemistry

Specimen Requirements

Patient Preparation: None

Collection Container/Tube:

Preferred: Mint green-top Lithium Heparin (MNTGRN LiHep) tube

Acceptable: Green samplette/microtainer, plain red-top tube, Gold SST gel tube, or Lavender-top (EDTA) tube

Submission Container/Tube: If specimen is coming from outside facility and collected in a microtainer, plain red-top tube, or lavender-top tube aliquot processed sample into a plastic vial for transport (labeling with specimen type).

Specimen Collection Volume: 1.0 mL (minimum 0.6 mL)

Special Instructions: None

 

Sample Rejection

Mislabled or unlabeled specimens

Logistics

Test Availability: Monday-Sunday

Cut-off time: None, performed as received

Turnaround Time: Same Day; 2 hours from receipt in performing lab

Reference Values

Reference Interval: 

<1 years: ≤ 30.0 mg/dL
1-3 years: ≤ 90.0 mg/dL
3-6 years: 25.0-150.0 mg/dL
6-14 years: 50.0-250.0 mg/dL
≥ 14 years: 70.0-400.0 mg/dL

Critical Value: None established

 

Methodology

Immunoturbidimetric Assay

Limitations

  • Artificially low results due to antigen excess may occur at 100 g/L (625 mcmol/L, 10000 mg/dL) in polyclonal specimens.
  • As with other turbidimetric or nephelometric procedures, this test may not provide accurate results in patients with monoclonal gammopathy due to individual sample characteristics, which can be assessed by electrophoresis. 

Additional Information

 FOR SLCH CORE LABORATORY USE ONLY

 Lab Processing Instructions: Centrifuge to separate. If specimen is collected in microtainer, plain red-top tube, or lavender-top tube aliquot sample into a Roche false-bottom tube for testing (labeling aliquot with specimen type).

Processed Volume: 0.3 mL plasma/serum

Analyte Stability:

Specimen Type Temperature Time
Whole Blood (unprocessed)  Ambient 8 hours
Plasma/Serum (processed) Refrigerated (preferred) 3 months  
  Ambient  3 months
  Frozen  6 months

Test Classification and CPT Code

82784

LOINC

2458-8

Last Reviewed

06/2025