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Test Code IGAS IgA Subclasses, Serum

Reporting Name

IgA Subclasses, S

Useful For

Investigation of immune deficiency due to IgA2 deficiency

 

Evaluating patients with anaphylactic transfusion reactions

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Supplies: Sarstedt Aliquot Tube 5 mL (T914)

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) 7 days
  Ambient  7 days
  Frozen  7 days

Reference Values

IgA

1-3.9 years: 5-194 mg/dL

4-6.9 years: 16-210 mg/dL

7-9.9 years: 27-227 mg/dL

10-11.9 years: 35-241 mg/dL

12-13.9 years: 43-252 mg/dL

14-15.9 years: 50-263 mg/dL

16-17.9 years: 57-274 mg/dL

>18 years: 85-499 mg/dL

 

IgA1

1-3.9 years: 6-163 mg/dL

4-6.9 years: 16-186 mg/dL

7-9.9 years: 26-209 mg/dL

10-11.9 years: 34-228 mg/dL

12-13.9 years: 40-243 mg/dL

14-15.9 years: 46-259 mg/dL

16-17.9 years: 53-274 mg/dL

>18 years: 76-328 mg/dL

 

IgA2

1-3.9 years: <0.5-12.4 mg/dL

4-6.9 years: <0.5-25.7 mg/dL

7-9.9 years: 1.5-38.9 mg/dL

10-11.9 years: 2.9-49.9 mg/dL

12-13.9 years: 4.0-58.7 mg/dL

14-15.9 years: 5.2-67.5 mg/dL

16-17.9 years: 6.3-76.3 mg/dL

>18 years: 6.9-114.3 mg/dL

Day(s) Performed

Tuesday, 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

82787 x 2

LOINC Code Information

Test ID Test Order Name Order LOINC Value
IGAS IgA Subclasses, S 87552-6

 

Result ID Test Result Name Result LOINC Value
IGA_ IgA 2458-8
IGA1_ IgA1 6886-6
IGA2_ IgA2 6939-3

Interpretation

Low concentrations of IgA2 with normal amounts of IgA1 suggest an IgA2 deficiency.

 

Elevated concentrations of IgA2 with normal or low amounts of IgA1 suggest a clonal plasma cell proliferative disorder secreting a monoclonal IgA2.

 

Increased total IgA concentrations may also be seen in benign disorders (eg, infection, inflammation, allergy), hyper IgD syndrome with periodic fever, and monoclonal gammopathies (eg, myeloma, monoclonal gammopathies of undetermined significance [MGUS]).

Clinical Reference

1. Schauer U, Stemberg F, Rieger CHL, et al. Establishment of age-dependent reference values for IgA subclasses. Clin Chim Acta. 2003;328(1-2):129-133

2. Saulsbury FT. Hyperimmunoglobulinemia D and periodic fever syndrome (HIDS) in a child with normal serum IgD, but increased serum IgA concentration. J Pediatrics. 2003;143(1):127-129

3. Popovsky MA. Transfusion Reactions. American Association of Blood Banks, 3rd ed, 2007

4. Derksen VFAM, Allaart CF, Van der Helm-Van Mil AHM, Huizinga TWJ, Toes REM, van der Woude D. In rheumatoid arthritis patients, total IgA1 and IgA2 levels are elevated: implications for the mucosal origin hypothesis. Rheumatology (Oxford). 2022;62(1):407-416. doi:10.1093/rheumatology/keac237

5. Dietzen DJ, Willrich MAV. Amino acids, peptides, and proteins. In: Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. 2023:chap 31

6. Steffen U, Koeleman CA, Sokolova MV, et al. IgA subclasses have different effector functions associated with distinct glycosylation profiles. Nat Commun. 2020;11(1):120. Published 2020 Jan 8. doi:10.1038/s41467-019-13992-8

Report Available

Same day/1 to 3 days

Method Name

Turbidimetry