Test ID: IGAAB
Anti-IgA Antibodies, IgG Class, Serum
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Evaluation of patients with a history of a severe transfusion reaction with signs of anaphylaxis
Identification of patients who require IgA-free blood products
Method Name A short description of the method used to perform the test
Fluorescent Microsphere Immunoassay
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Anti-IgA Antibody
IgA (Immunoglobulin A) Antibodies
IgA Antibodies - IgG, Anti-IgA Antibodies
IgG, Anti-IgA Antibodies
IgG-IgA Antibodies
Immunoglobulin A (IgA) Antibodies
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Specimen Volume: 1 mL
Additional Information:
1. If testing is due to a transfusion reaction, the specimen should be drawn approximately a minimum of 10 days after the reaction.
2. Testing performed on serum drawn immediately after a reaction may be falsely negative as transfused IgA may deplete anti-IgA antibodies.
Forms: If not ordering electronically, submit a General Request Form (Supply T239) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross OK |
| Lipemia | Mild OK; Gross OK |
| Icterus | Mild OK; Gross OK |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Frozen (preferred) | 14 days |
| Refrigerated | 14 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Anaphylactic transfusion reactions induced by IgG anti-IgA antibodies may occur in IgA-deficient patients. Anaphylactic and anaphylactoid reactions are mediated by activation of complement with generation of vasoactive anaphylatoxins (C3a, C4a, and C5a). These reactions are characterized by urticaria, hypotension, and respiratory distress with bronchospasm or stridor.
Patients with IgA deficiency who require blood or blood component transfusions should receive IgA-free blood products. Patients with a history of a severe transfusion reaction with signs of anaphylaxis, who are known to be IgA deficient, should be tested for the presence of IgG anti-IgA antibodies prior to the anticipated need for blood or blood components. This will allow time for preparation of IgA-free blood products, if indicated.
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.
Negative: < or =52.0 U
Positive: >52.0 U
Pediatric reference ranges are not established.
Interpretation Provides information to assist in interpretation of the test results
Positive results occur in IgA-deficient patients who have experienced an anaphylactic reaction associated with transfusion of blood or blood components that contain plasma.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Negative test results do not conclusively rule out the possibility of future anaphylactic transfusion reactions:
-Antibodies to other plasma proteins may be associated with release of vasoactive mediators.
-Testing performed on sera drawn immediately after a reaction may be falsely negative due to transfused IgA, which may deplete anti-IgA antibodies. Serum should be drawn a minimum of 10 days after the reaction.
The presence of IgG antibodies to IgA interfere analytically with detection of other anti-IgA isotypes (eg, IgE anti-IgA).
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Homburger HA, Smith JR, Jacob GL, et al: Measurement of anti-IgA antibodies by a two-site immunoradiometric assay. Transfusion 1981;21:38-44
2. Davenport RD, Mintz PD: Transfusion medicine. In Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st edition. Edited by RA McPherson, MR Pincus. Philadelphia, Saunders Elsevier, 2006, pp 707-708
3. Vassalo RR: Review: IgA anaphylactic transfusion reactions. Part I. Laboratory diagnosis, incidence, and supply of IgA-deficient products. Immunohematology 2004;20(4):226-233
4. Sandler SG, Zantek ND: Review: IgA anaphylactic transfusion reactions. Part II. Clinical diagnosis and bedside management. Immunohematology 2004;20(4):234-238
Method Description Describes how the test is performed and provides a method-specific reference
Highly purified polyclonal human IgA coupled covalently to fluorescent microspheres is used as a binder for specific IgG anti-IgA antibodies in serum. After incubating serum with the IgA-coupled microspheres, the microspheres are washed to remove unbound IgG. Fluorochrome-labeled antihuman IgG is added to detect specific IgG antibodies bound during the first incubation. Results are expressed in arbitrary units (U) by comparison to a calibrator known to contain IgG anti-IgA antibodies.(Modified from Rumilla KM, Winters JL, Peterman JM, et al: development and validation of a fluorescent microsphere immunoassay for anti-IgA. Immunohematol 2009;25[1]:24-28)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Tuesday, Friday; 8 a.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
83520
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| 28049 | Anti-IgA Ab, IgG, S | 13312-4 |
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