Anti-glomerular basement membrane
DefinitionThe glomerular basement membrane is the part of the kidney that helps filter waste and extra fluid from the blood.Anti-glomerular basement membrane antibodies are antibodies against this membrane. They can lead to kidney damage. This article describes the blood test to detect these antibodies.
Alternative NamesGBM antibody test; Antibody to human glomerular basement membrane; Anti-GBM antibodies
How the test is performedBlood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
How to prepare for the testNo special preparation is necessary.
How the test will feelWhen the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performedThis test is used to diagnose certain kidney diseases, such as Goodpasture syndrome and anti-glomerular basement membrane disease.
Normal ValuesNormally, there are none of these antibodies in the blood.Note: Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What abnormal results meanAnti-glomerular basement membrane diseaseGoodpasture syndrome
What the risks areVeins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.Other risks:Excessive bleedingFainting or feeling light-headedHematoma (blood accumulating under the skin)Infection (a slight risk any time the skin is broken)
ReferencesAppel GB. Glomerular disorders and nephrotic syndromes. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 122.Appel GB, Radhakrishnan J, D'Agatis V. Secondary glomerular disease. In: Brenner BM, ed. Brenner and Rector's The Kidney. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 31.