ANTI-GBM ANTIBODIES

ANTI-GBM ANTIBODY INTERPRETATIONS

NEGATIVE
INDETERMINATE
WEAK POSITIVE
POSITIVE
STRONG POSITIVE
ADDENDUM TO INTERPS:

Gives background info regarding anti-GBM testing for Goodpasture's syndrome

NEGATIVE
*** ANTI-GBM ANTIBODY TESTING BY EIA ***
TEST RESULT INTERPRETATION
Anti-GBM Ab EIA ## SLI Units NOT DETECTED
The anti-GBM Ab EIA is measured in SLI (Specialty Labs, Inc) Units
REFERENCE RANGE INTERPRETATION
0-10 SLI Units Not Detected
11-15 Borderline
16-20 Weak Positive
21-100 Positive
100+ Strong Positive

INTERPRETATION: Antibodies against the glomerular basement membrane are not detected in this sample. EIA is a highly sensitive and specific assay for anti-GBM and the failure to detect these autoantibodies argues strongly against the diagnosis of untreated Goodpasture's syndrome.
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INDETERMINATE
*** ANTI-GBM ANTIBODY TESTING BY EIA ***
TEST RESULT INTERPRETATION
Anti-GBM Ab EIA ## SLI Units INDETERMINATE
The anti-GBM Ab EIA is measured in SLI (Specialty Labs, Inc) Units
REFERENCE RANGE INTERPRETATION
0-10 SLI Units Not Detected
11-15 Borderline
16-20 Weak Positive
21-100 Positive
100+ Strong Positive

INTERPRETATION: EIA for anti-glomerular basement membrane autoantibodies gives a borderline result. This result is not diagnostic for Goodpasture's syndrome. However, if there is strong clinical suspicion of this disease, prompt (not greater than one week) retesting is recommended. EIA is a highly sensitive and specific assay for anti-GBM, and a positive result strongly supports the diagnosis of Goodpasture's syndrome, while a negative result is strong evidence against this diagnosis.
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WEAK POSITIVE
*** ANTI-GBM ANTIBODY TESTING BY EIA ***
TEST RESULT INTERPRETATION
Anti-GBM Ab EIA ## SLI Units WEAK POSITIVE
SLI Accession #:
The anti-GBM Ab EIA is measured in SLI (Specialty Labs, Inc) Units
REFERENCE RANGE INTERPRETATION
0-10 SLI Units Not Detected
11-15 Borderline
16-20 Weak Positive
21-100 Positive
100+ Strong Positive

INTERPRETATION: This sample tests weakly positive for anti-glomerular basement membrane antibodies by EIA. EIA is a highly sensitive and specific assay for anti-GBM, and the detection of low levels of these autoantibodies supports the diagnosis of Goodpasture's syndrome. Levels of anti-GBM correlate with disease activity. Therefore, follow-up quantitation is useful for monitoring response to therapy. Please provide the SLI accession number of this specimen when submitting follow-up specimens. The specimens will be tested simultaneously to optimize the utility of the results. All sera are stored frozen for six weeks for additional testing.
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POSITIVE
*** ANTI-GBM ANTIBODY TESTING BY EIA ***
TEST RESULT INTERPRETATION
Anti-GBM Ab EIA ## SLI Units POSITIVE
SLI Accession #:
The anti-GBM Ab EIA is measured in SLI (Specialty Labs, Inc) Units
REFERENCE RANGE INTERPRETATION
0-10 SLI Units Not Detected
11-15 Borderline
16-20 Weak Positive
21-100 Positive
100+ Strong Positive

INTERPRETATION: This sample tests positive for anti-glomerular basement membrane antibodies by EIA. EIA is a highly sensitive and specific assay for anti-GBM, and the detection of these autoantibodies strongly supports the diagnosis of Goodpasture's syndrome. Levels of anti-GBM correlate with disease activity. Therefore, follow-up quantitation is useful for monitoring response to therapy. Please provide the SLI accession number of this specimen when submitting follow-up specimens. The specimens will be tested simultaneously to optimize the utility of the results. All sera are stored frozen for six weeks for additional testing.
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STRONGLY POSITIVE
*** ANTI-GBM ANTIBODY TESTING BY EIA ***
TEST RESULT INTERPRETATION
Anti-GBM Ab EIA ## SLI Units STRONG POSITIVE
SLI Accession #:
The anti-GBM Ab EIA is measured in SLI (Specialty Labs, Inc) Units
REFERENCE RANGE INTERPRETATION
0-10 SLI Units Not Detected
11-15 Borderline
16-20 Weak Positive
21-100 Positive
100+ Strong Positive

INTERPRETATION: This sample tests strongly positive for anti-glomerular basement membrane antibodies by EIA. EIA is a highly sensitive and specific assay for anti-GBM, and the detection of these autoantibodies strongly supports the diagnosis of Goodpasture's syndrome. Levels of anti-GBM correlate with disease activity. Therefore, follow-up quantitation is useful for monitoring response to therapy. Please provide the SLI accession number of this specimen when submitting follow-up specimens. The specimens will be tested simultaneously to optimize the utility of the results. All sera are stored frozen for six weeks for additional testing.
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ADDENDUM TO INTERPS
BACKGROUND: Anti-glomerular basement membrane (GBM) autoantibodies are strongly associated with Goodpasture's syndrome (glomerulonephritis and pulmonary hemorrhage). Enzyme immunoassay (EIA) has replaced immunofluorescence as the method of choice for detecting and quantitating anti-GBM antibodies, due to its greater sensitivity and specificity (>99% in most studies). Thus, the identification of anti-GBM antibodies by EIA strongly supports the diagnosis of Goodpasture's syndrome and follow-up quantitation is useful for monitoring response to therapy. Conversely, the failure to detect anti-GBM by EIA argues strongly against the diagnosis of untreated Goodpasture's syndrome. The specific detection of anti-GBM antibodies is important for confirming the diagnosis because roughly 10% of renal biopsies show nonspecific linear deposits on the GBM that resemble those seen in Goodpasture's syndrome, and immune complex glomerulonephritis can be associated with pulmonary hemorrhage and thus can be difficult to distinguish clinically from Goodpasture's syndrome.
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