Glomerular Basement Membrane Antibodies, IgG

Label Mnemonic:	GBM
Epic code:	LAB1255
Order form:	Laboratory Requisition
Supply order:	Supply Order Form
Billing:	Billing Policies
CPT code:	83520

Specimen(s):

Serum

Collection Medium:

Red top tube 5 mL (Clot Activator)

Minimum:

Adult - 5 mL; red top tube
Pediatric - 2 mL; red top tube

Testing Schedule:

24 hrs/day, 7 days a week, including holidays.

Turn Around Time:

3 hours (upon receipt in laboratory)

Reference Range:

Negative: < 0.4 antibody index (AI)
Equivocal: 0.4-0.9
Positive: 1.0 AI or greater

Interpretive Data:

Glomerular basement membrane (GBM) antibodies are used for evaluating with rapid onset renal failure or pulmonary hemorrhage and as an aid in the diagnosis of Goodpasture syndrome in conjunction with clinical history and physical examination. Positive results for GBM antibodies are consistent with Goodpasture syndrome. GBM antibodies are highly specific for Goodpasture syndrome. The sensitivity of this test is approximately 87% in untreated patients with systemic disease.

Comments:

Assay methodology and reference ranges changed February 5, 2013.

References:
Pusey CD. Anti-glomerular basement membrane disease. Kidney Int 2003; 64:1535-1550.

Methodology:

Multiplex flow immunoassay

Sample Processing:

Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells.
Separate plasma or serum into labeled container and cap.

Sample Storage:

Refrigerate.

Transport Instructions:

Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.

CPT Code:

83520