Supporting the diagnosis of Wilson disease
Test Id | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
IHTOI | IHC Initial, Tech Only | No | No |
IHTOA | IHC Additional, Tech Only | No | No |
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).
Immunohistochemistry (IHC)
MT
Metallothionein
Wilson disease
Wilson's disease
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).
TECHONLY
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.
Attach the green pathology address label and the pink Immunostain Technical Only label included in the kit to the outside of the transport container.
Specimen Type: Tissue
Supplies: Immunostain Technical Only Envelope (T693)
Container/Tube: Immunostain Technical Only Envelope
Preferred:
-Formalin-fixed, paraffin-embedded tissue block
OR
-2 Unstained, positively charged glass slides (25- x 75- x 1-mm) per test ordered; sections 4-microns thick
Acceptable: None
1. Information on accessing digital images of immunohistochemical (IHC) stains and the manual requisition form can be accessed through this website: https://news.mayocliniclabs.com/ihc-stains/
2. Clients ordering stains using a manual requisition form will not have access to digital images.
3. Clients wishing to access digital images must place the order for IHC stains electronically. Information regarding digital imaging can be accessed through this website: https://news.mayocliniclabs.com/ihc-stains/#FAQ
If not ordering electronically, complete, print, and send a Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763) with the specimen.
See Specimen Required
Wet/frozen tissue Cytology smears Nonformalin fixed tissue Nonparaffin embedded tissue Noncharged slides ProbeOn slides Snowcoat slides | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
TECHONLY | Ambient (preferred) | ||
Refrigerated |
Supporting the diagnosis of Wilson disease
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).
This test is intended to identify the presence of metallothionein (MT). MT is useful to support a diagnosis of Wilson disease (WD). MT plays a role in binding the accumulated copper in WD disorder. MT can detect even early-stage cases of WD before the development of cirrhosis. The MT assay has been shown to have higher sensitivity and specificity compared to the use of the Leipzig criteria and rhodanine. MT expression by IHC is a more cost effective and practical approach compared to quantitative liver copper assays.
This test does not include pathologist interpretation only technical performance of the stain. If interpretation is required order PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case.
The positive and negative controls are verified as showing appropriate immunoreactivity and documentation is retained at Mayo Clinic Rochester. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request. Contact 855-516-8404.
Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.
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.
The charge of glass slides can be affected by environmental factors and subsequently may alter slide staining. Sending unsuitable glass slides can result in inconsistent staining due to poor slide surface chemistry.
Best practices for storage of positively charged slides:
-Minimize time slides are stored after being unpackaged
-Limit exposure to high humidity and heat
-Minimize exposure to plastics
1. Rowan D, Mangalaparthi KK, Singh S, et al. Metallothionein immunohistochemistry has high sensitivity and specificity for detection of Wilson disease. Mod Pathol. 2022;35(7):946-955
2. Poujois A, Woimant F. Wilson's disease: A 2017 update. Clin Res Hepatol Gastroenterol. 2018;42(6):512-520
3. Mulder TP, Janssens AR, Verspaget HW, et al. Metallothionein concentration in the liver of patients with wilson's disease, primary biliary cirrhosis, and liver metastasis of colorectal cancer. J Hepatol. 1992;16(3):346-350
4. Petering DH, Fowler BA. Roles of metallothionein and related proteins in metal metabolism and toxicity: problems and perspectives. Environ Health Perspect. 1986;65:217-224
Immunohistochemistry on sections of paraffin-embedded tissue.(Unpublished Mayo method)
Monday through Friday
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.
88342-TC, primary
88341-TC, if additional IHC
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
MT | Metallothionein IHC, Tech Only | No LOINC Needed |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
619973 | Metallothionein IHC, Tech Only | No LOINC Needed |
Change Type | Effective Date |
---|---|
New Test | 2023-10-23 |