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HelpTest Code KM55 Galactose Deficient IgA1 (KM55) Immunostain, Technical Component Only
Test Down Notes
This test is temporarily unavailable. For additional details, see test update here. https://www.mayocliniclabs.com/test-notifications/attachment.php?id=80791
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
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
Secondary ID
621066Useful For
Identification of Galactose deficient IgA1 by KM55, useful in the diagnosis of IgA 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
KM55 IHC, Tech OnlySpecimen Type
TECHONLYSpecimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| TECHONLY | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
| Wet/frozen tissue Cytology smears Nonformalin fixed tissue Nonparaffin embedded tissue Noncharged slides ProbeOn slides Snowcoat slides |
Reject |
Clinical Information
KM55 antibody has been shown to identify galactose deficient IgA1 (Gd-IgA1), useful in the diagnosis of IgA nephropathy. Gd-IgA1 (KM55) is detected in the glomeruli of patients with IgA nephropathy and IgA vasculitis and may aid in distinguishing IgA nephropathy and IgA vasculitis from other glomerular diseases with IgA deposits detected by routine IgA staining.
Interpretation
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. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request; call 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.
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.
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
Clinical Reference
1. Bu L, Ye B, Kouri AM, Kim Y. Diagnostic Utility of Galactose-Deficient Immunoglobulin A1 Immunostaining in the Differentiation of Lupus Nephritis and Immunoglobulin A Nephropathy. Glomerular Dis. 2021;1(1):34-39. Published 2021 Mar 10. doi:10.1159/000511056
2. Suzuki H, Yasutake J, Makita Y, et al. IgA nephropathy and IgA vasculitis with nephritis have a shared feature involving galactose-deficient IgA1-oriented pathogenesis. Kidney Int. 2018;93(3):700-705. doi:10.1016/j.kint.2017.10.019
3. Raj R, Sharma A, Barwad A, et al. KM55 in the Evaluation of IgA-Containing Glomerular Diseases. Glomerular Dis. 2021;2(2):59-74. Published 2021 Nov 2. doi:10.1159/000520640
4. Zhang K, Li Q, Zhang Y, et al. Clinical Significance of Galactose-Deficient IgA1 by KM55 in Patients with IgA Nephropathy. Kidney Blood Press Res. 2019;44(5):1196-1206. doi:10.1159/000502579
Method Description
Immunohistochemistry on sections of paraffin-embedded tissue.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
1 to 3 daysSpecimen Retention Time
Until staining is completePerforming 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
LOINC Code Information
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 621067 | KM55 IHC, Tech Only | No LOINC Needed |
Forms
If not ordering electronically, complete, print, and send a Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request (T763) with the specimen.