Anti-glomerular basement membrane antibody disease

Definition

Goodpasture syndrome is a disease that affects the kidneys and lungs. It usually involves rapidly progressive kidney failure

Some forms of the disease involve just the lung or kidney problems, not both.

Alternative Names

Causes

Goodpasture syndrome is an autoimmune disorder. This means your body makes antibodies that attack your own body tissues. In this case, antibodies form against a certain type of protein called collagen. The collagen is present in the alveoli (tiny air sacs in the lungs) and in the glomeruli (the filtering units of the kidney). These antibodies are called anti-glomerular basement membrane antibodies (or anti-GBM antibodies).

Sometimes the disorder is triggered by a viral respiratory infection or by inhaling hydrocarbon solvents. In such cases, the immune system may attack organs or tissues because it mistakes them for these viruses or foreign chemicals.

The antibody attack leads to bleeding in the air sacs, which causes shortness of breath, cough, and bloody sputum. It also causes inflammation in the glomeruli of the kidney, which causes blood in urine (hematuria), protein in the urine (proteinuria), or kidney failure.

Symptoms

• Bloody urine
• Dark colored urine
• Decreased urine output
• Foamy urine
• Cough with bloody sputum (coughing up blood)
• Difficulty breathing after exertion
• Weakness
• Nausea and vomiting
• Chest pain
• Pale skin

Exams and Tests

During a physical examination, the health care provider will usually discover that the patient has high blood pressure. The patient usually has signs of fluid overload, such as swelling, gallop rhythms of the heart, and crackle sounds in the lungs. The crackles may also be from blood in the air sacs.

The following are relevant test results:

• Urinalysis shows blood and protein in the urine. Abnormal red blood cells may be seen.
• BUN and creatinine levels are elevated.
• Chest x-ray shows diseased alveoli.
• Arterial blood gas analysis may show low oxygen in the blood.
• Lung biopsy shows damaged alveoli.
• Kidney biopsy shows damaged glomeruli.
• Anti-GBM antibody levels are elevated.

Treatment

The main goal is to remove the circulating antibodies from the blood. An early diagnosis is very important. The patient's outlook is much worse if the kidneys are already severely damaged when treatment begins.

Plasmapheresis is a procedure where blood plasma is removed from the circulation and replaced by fluid, protein, or donated plasma. This helps to make sure that harmful antibodies are removed.

Anti-inflammatory and cytotoxic agents (such as prednisone or cyclophosphamide) may be needed.

If kidney failure becomes severe, dialysis may be needed to substitute for the kidney's normal functioning.

Kidney transplantation may be performed in patients who suffer irreversible loss of kidney function. The nephrologist (a specialist physician) would usually wait for the levels of circulating anti-GBM antibodies to drop before proceeding with the transplant.

Outlook (Prognosis)

The outlook varies. Early diagnosis and treatment tend to have better outcomes.

Possible Complications

• Rapidly progressive glomerulonephritis
• Chronic kidney failure
• End-stage kidney disease
• Severe pulmonary hemorrhage (lung bleeding)
• Respiratory failure

When to Contact a Medical Professional

Call for an appointment with your health care provider if the amount of urine you produce drops, or if you have any other symptoms of Goodpasture syndrome.

Prevention

Never sniff glue or siphon gasoline, which expose the lungs to hydrocarbon solvents and can cause the disease. Early diagnosis and treatment may slow the progression of the disorder.