ARUP's Laboratory Test Directory

Glomerular Basement Membrane Antibody, IgG (IFA) : 0049191

Mnemonic: GBM-G IFA

Methodology: Indirect Fluorescent Antibody
Performed: Mon-Fri
Reported: Within 5 days
Specimen Required: Collect: Serum separator tube.

Specimen Preparation: Separate serum from cells ASAP or within 2 hours of collection. Transport 1 mL serum. (Min: 0.5 mL)

Storage/Transport Temperature: Refrigerated.

Stability (collection to initiation of testing): After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Reference Interval:
Negative
Interpretive Data: The anti-GBM IFA methodology has been shown to be less specific than the semi-quantitative tests for circulating antibodies, such as the Glomerular Basement Membrane Antibody, IgG by Multiplex Bead Assay (ARUP Test Code 0051000). The antibody used in the Multiplex Bead Assay, although directed to human IgG F(ab')2, can bind to light chain sites common to all immunoglobulins, causing the assay to be more sensitive but less specific. The determination of a positive result is based on a diffuse "linear" staining pattern as viewed through a fluorescent microscope. All positive results should be confirmed by semi-quantitative tests and/or renal biopsy.

See Compliance Statement D: www.aruplab.com/CS
CPT Code(s): 86255
Cross References: Anti-GBM Antibody (Glomerular Basement Membrane Antibody, IgG (IFA)), Anti-Glomerular Basement Membrane Antibody (Glomerular Basement Membrane Antibody, IgG (IFA)), Goodpasture's Syndrome (Glomerular Basement Membrane Antibody, IgG (IFA))