Immunoglobulin G4 by Immunohistochemistry

Casandra

Casandra Test Code AR66955Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 2005844CPT Code 88342

Immunoglobulin G4 by Immunohistochemistry

Also known as: IGG4 IHC

Clinical Use

Order Test

Use

Immunoglobulin G4 (IgG4) by immunohistochemistry is used in the identification and quantification of IgG4 positive plasma cells within tissue specimens. This staining technique is particularly beneficial in the diagnosis and assessment of IgG4-related disease, a condition characterized by increased levels of IgG4 producing cells, which can lead to tissue fibrosis and organ dysfunction. The test provides valuable information for pathologists in evaluating tissue specimens for the presence of IgG4-related disease.

Special Instructions

Not provided.

Limitations

This test is provided as a technical service only, with the interpretation of the staining left to the ordering pathologist. It is crucial for pathologists to consider the entire clinical context and additional diagnostic information when interpreting IgG4 stains. Over-reliance on IgG4 staining without considering other diagnostic data may lead to inappropriate clinical conclusions. Additionally, the test's effectiveness and accuracy depend greatly on sample quality and preparation parameters.

Test Details

New York Approved

Methodology

Immunoassay (IHC)

Biomarkers

IgG4

Protein

IHC

Expression • Ordinal Score (e.g., TPS, CPS, H-score)

LOINC Codes

Order Codes

94736-6 - Tissue block ID Spec

Result Codes

49471-6 - IgG4 Ag Tiss Ql ImStn

Result Turnaround Time

1-3 days

Specimen

Tissue (FFPE)

Volume

Not provided

Minimum Volume

2 slides

Container

Tissue block or positively charged slides

Collection Instructions

Collect tissue or cells. Formalin fix (10 percent neutral buffered formalin) and paraffin embed specimen (cells must be prepared into a cellblock). Protect paraffin block and/or slides from excessive heat.