What are other Names for this Test? (Equivalent Terms)
- AGBM Blood Test
- Anti-GBM Blood Test
- Glomerular Basement Membrane Antibody Blood Test
What is the Antiglomerular Basement Membrane Antibody Blood Test? (Background Information)
- The glomerular basement membrane is the structural foundation of the glomeruli (plural for glomerulus). Glomeruli are the microscopic sieve-like structures of the kidneys that filter blood. There are roughly 1 million glomeruli in each kidney
- Glomeruli receive blood from tiny capillaries carrying blood from outside the kidneys. This blood encounters 3 levels of filtration
- First, the endothelial cells of the glomerulus form pores through which large and small molecules and proteins may pass
- This crude filtrate then goes through the glomerular basement membrane, which filters out large substances
- Specialized cells, called podocytes, form a 3rd layer of filtration, which serves as an ultra-fine filter
- In rare instances, autoantibodies may form and these target the glomerular basement membrane. Antibodies are defense proteins that rid the body of invaders; autoantibodies are antibodies that mistake the body’s own tissues as invaders and cause autoimmune disorders
- Autoantibody attack of the glomerular filtering mechanism may damage the kidneys. This may lead to the accumulation of substances, such as proteins and sugars, in urine and blood
- The Antiglomerular Basement Membrane Antibody Blood Test detects autoantibodies specific to the basement membrane of the glomerulus. It is used to diagnose autoimmune kidney disease
What are the Clinical Indications for performing the Antiglomerular Basement Membrane Antibody Blood Test?
Following are the clinical indications for performing the Antiglomerular Basement Membrane Antibody Blood Test:
- Evaluating kidney disease
- Frequent urination
- Blurry vision
- Rapid weight loss
How is the Specimen Collected for the Antiglomerular Basement Membrane Antibody Blood Test?
Following is the specimen collection process for Antiglomerular Basement Membrane Antibody Blood Test:
Sample required: Blood
Process of obtaining blood sample in adults:
- A band is wrapped around the arm, 3-4 inches above the collection site (superficial vein that lies within the elbow pit)
- The site is cleaned with 70% alcohol in an outward spiral, away from the zone of needle insertion
- The needle cap is removed and is held in line with the vein, pulling the skin tight
- With a small and quick thrust, the vein is penetrated using the needle
- The required amount of blood sample is collected by pulling the plunger of the syringe out slowly
- The wrap band is removed, gauze is placed on the collection site, and the needle is removed
- The blood is immediately transferred into the blood container, which has the appropriate preservative/clot activator/anti-coagulant
- The syringe and the needle are disposed into the appropriate “sharp container” for safe and hygienic disposal
Preparation required: No special preparation is needed prior to the test.
What is the Significance of the Antiglomerular Basement Membrane Antibody Blood Test Result?
A positive Antiglomerular Basement Membrane Antibody Blood Test result may indicate:
- Anti-GBM nephritis
- Tubulointerstitial nephritis
- Pulmonary capillary basement membranes
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider of the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.
What are some Useful Resources for Additional Information?
The following DoveMed website links are some useful resources for additional information:
Please visit our Laboratory Procedures Center for more physician-approved health information:
References and Information Sources used for the Article:
Kee, J. L. (2010). Laboratory and diagnostic tests with nursing implications (8th ed.). Upper Saddle River, NJ: Pearson.
Martini, F., Nath, J. L., & Bartholomew, E. F. (2012). Fundamentals of anatomy & physiology (9th ed.). San Francisco: Benjamin Cummings.
Schnell, Z. B., Van, L. A., & Kranpitz, T. R. (2003). Davis's Comprehensive handbook of laboratory and diagnostic tests: With nursing implications. Philadelphia: F.A. Davis.