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Test ID EXT2 Exostosin 2 (EXT2) 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 a Renal Diagnostics Test Request (T830) with the specimen.

Secondary ID

614548

Useful For

Identification of exostosin 2 associated membranous nephropathy

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

EXT2 IHC, Tech Only

Specimen Type

TECHONLY

Specimen Stability Information

Specimen Type Temperature Time
TECHONLY Ambient (preferred)
  Refrigerated 

Clinical Information

Primary membranous nephropathy is an autoimmune disease of the kidney where antibodies target an antigen in the glomerular basement membrane resulting in kidney damage or failure. In up to 75% of primary membranous nephropathy cases phospholipase A2 receptor (PLA2R) and thrombospondin type-1 domain-containing 7A (THSD7A) are the target antigens. Exostosin 1 (EXT1) and exostosin 2 (EXT2), a recently identified set of novel proteins are associated with a subset of PLA2R and TSD7A double-negative MN. EXT1 and EXT2 may represent the target antigens or biomarker proteins of secondary (autoimmune) MN.

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 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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

NY State Approved

Yes