Antibodies, Anti-Glomerular Basement Membrane

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Antibodies, Anti-Glomerular Basement Membrane

Synonym/acronym: Goodpasture’s antibody, anti-GBM.

Common use

To assist in differentiating Goodpasture’s syndrome (an autoimmune disease) from renal dysfunction.

Specimen

Serum (1 mL) collected in a gold-, red-, or red/gray-top tube. Lung or kidney tissue also may be submitted for testing. Refer to related biopsy monographs for specimen-collection instructions.

Normal findings

(Method: Enzyme immunoassay) Less than 20 units/mL = negative.

Description

Glomerulonephritis or inflammation of the kidney is initiated by an immune response, usually to an infection. It can be classified as either antibody-mediated or cell-mediated glomerulonephritis. Goodpasture’s syndrome is a rare hypersensitivity condition characterized by the presence of circulating anti-glomerular basement membrane (GBM) antibodies in the blood and the deposition of immunoglobulin and complement in renal basement membrane tissue. Severe and progressive glomerulonephritis can lead to the development of pulmonary hemorrhage and idiopathic pulmonary hemosiderosis. The presence of anti-GBM antibodies can also be demonstrated in renal biopsy tissue cells of affected patients. Autoantibodies may also be directed to act against lung tissue in Goodpasture’s syndrome.

This procedure is contraindicated for

    N/A

Indications

  • Differentiate glomerulonephritis caused by anti-GBM from glomerulonephritis from other causes
  • Monitor therapy for glomerulonephritis caused by anti-GBM

Potential diagnosis

Increased in

  • Glomerulonephritis (of autoimmune origin as evidenced by the presence of anti-GBM antibodies)
  • Goodpasture’s syndrome (related to nephritis of autoimmune origin)
  • Idiopathic pulmonary hemosiderosis

Decreased in

    N/A

Critical findings

    N/A

Interfering factors

    N/A

Nursing Implications and Procedure

Pretest

  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient this test can assist in diagnosing a disease that can affect the kidneys or lungs.
  • Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
  • Obtain a history of the patient’s genitourinary, immune, and respiratory systems; symptoms; and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values).
  • Review the procedure with the patient. Inform the patient that specimen collection takes approximately 5 to 10 min. Address concerns about pain and explain that there may be some discomfort during the venipuncture.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Note that there are no food, fluid, or medication restrictions unless by medical direction.

Intratest

  • Potential complications: N/A
  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection. Perform a venipuncture.
  • Remove the needle and apply direct pressure with dry gauze to stop bleeding. Observe/assess venipuncture site for bleeding or hematoma formation and secure gauze with adhesive bandage.
  • Promptly transport the specimen to the laboratory for processing and analysis.

Post-Test

  • Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
  • Recognize anxiety related to test results, and be supportive of perceived loss of independence and fear of shortened life expectancy. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate. Educate the patient regarding access to counseling services.
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
  • Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

  • Related tests include ANCA, biopsy kidney, biopsy lung, IVP, renogram, US kidney, and UA.
  • See the Genitourinary, Immune, and Respiratory systems tables at the end of the book for related tests by body system.
References in periodicals archive ?
Excellent bio-distribution into the brain is also believed to contribute to the anti-GBM xenograft activity of NT-113.
In this setting, patients have a worse prognosis than ANCA isolated conditions, with a clinical course more similar to pure anti-GBM disease.
Anti-GBM disease has similar features on light microscopy, with the addition of positive linear basement membrane staining with IgG in the glomeruli.
Anti-GBM disease is a diagnosis that is made when there is a presence of circulating anti-GBM antibodies in the serum.
Patient monitoring for ITP, thyroid disorders and anti-GBM disease is incorporated into all Genzyme-sponsored trials of alemtuzumab for the treatment of multiple sclerosis.
62) Our study indicated that 92% of patients had circulating anti-GBM in serum, usually at high titers (Table 1).
The second is to stop the production of the anti-GBM antibodies using immunosuppressive medications.
Numerous studies have shown poor outcome in patients with initial creatinine levels greater than 5 mg/dL, crescent formation in more than 50% of glomeruli, oligoanuria, and circulating anti-GBM.
In general, anti-GBM GN and pauci-immune GN have a higher frequency and severity of crescent formation.
Tests performed subsequently for circulating anti-GBM antibodies also produced negative results.
Immunofluorescence microscopy showed coarse linear and pseudolinear deposition of polyclonal IgG and C3 along the capillary walls without significant mesangial deposits, One of the common causes of crescentic GN is anti-GBM crescentic GN.
Patient monitoring for thyroid disorders, ITP, and anti-GBM disease is incorporated into all Genzyme-sponsored trials of alemtuzumab for the investigational treatment of MS.