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.
Compliance Statement D
: This test was developed and its performance characteristics determined by ARUP Laboratories. The U.S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.