Test ID IGG4I IgG4 Immunostain, Technical Component Only
Ordering Guidance
This test includes only technical performance of the stain (no pathologist interpretation is performed). If diagnostic consultation by a pathologist is required order PATHC / Pathology Consultation.
Shipping Instructions
Attach the green "Attention Pathology" address label (T498) and the pink Immunostain Technical Only label included in the kit to the outside of the transport container.
Specimen Required
Supplies: Immunostain Technical Only Envelope (T693)
Specimen Type: Tissue
Container/Tube: Immunostain Technical Only Envelope
Preferred: 2 Unstained positively charged glass slide (25- x 75- x 1-mm) per test ordered; sections 4-microns thick.
Acceptable: Formalin-fixed, paraffin-embedded tissue block
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763)
-Renal Diagnostics Test Request (T830)
Secondary ID
70472Useful For
Identification of IgG4-positive plasma cells in the tissue of patients with systemic autoimmune or allergic manifestations
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
IHTOI | IHC Initial, Tech Only | No | No |
IHTOA | IHC Additional, Tech Only | No | No |
Testing Algorithm
For the initial technical component only immunohistochemical (IHC) stain performed, the appropriate bill-only test ID will be reflexed and charged (IHTOI). For each additional technical component only IHC stain performed, an additional bill-only test ID will be reflexed and charged (IHTOA).
Method Name
Immunohistochemistry (IHC)
Reporting Name
IgG4 IHC, Tech OnlySpecimen Type
TECHONLYSpecimen Stability Information
Specimen Type | Temperature | Time | |
---|---|---|---|
TECHONLY | Ambient (preferred) | ||
Refrigerated |
Clinical Information
Immunoglobulin G4 is the least abundant of IgG subclasses, normally comprising 6% of total IgG. Elevated serum IgG4 levels may be associated with localized or systemic allergic and autoimmune manifestations, such as inflammatory pseudotumor in liver, breast, and lung, sclerosing pancreatitis, and pemphigus vulgaris. In these disease states, increased numbers of IgG4-positive plasma cells are present in the tissue.
Cautions
Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen dependent. Best practice is for paraffin sections to be cut within 6 weeks.
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysPerforming Laboratory

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
88342-TC, primary
88341-TC, if additional IHC