Creatinine is a waste product from the normal breakdown of muscle tissue. As creatinine is produced, it's filtered through the kidneys and excreted in urine. Doctors measure the blood creatinine level as a test of kidney function. The kidneys' ability to handle creatinine is called the creatinine clearance rate, which helps to estimate the glomerular filtration rate (GFR) -- the rate of blood flow through the kidneys.
Goodpasture syndrome initially causes vague symptoms such as fatigue. But it can rapidly involve the lungs and kidneys. It is almost always fatal if it is not quickly diagnosed and treated.
Causes of Goodpasture Syndrome
Researchers do not fully understand why the immune system attacks collagen in the lungs and kidneys. Goodpasture syndrome can run in families. So some researchers believe it may have a genetic component.
Other factors that may increase the risk of Goodpasture syndrome include:
Exposure to certain chemicals, such as hydrocarbon solvents and the weed killer paraquat
Exposure to metallic dust
Use of certain drugs, such as cocaine
Goodpasture syndrome usually affects young men. It more often occurs among whites than among people of other races and ethnicities. Goodpasture syndrome also most commonly affects people who are:
Between ages 20 and 30
Older than age 60
Symptoms of Goodpasture Syndrome
The first signs of Goodpasture syndrome may include:
Nausea and vomiting
Because Goodpasture syndrome may rapidly involve the lungs, initial symptoms such as shortness of breath can quickly progress to a persistent cough, sometimes with blood.
When Goodpasture syndrome affects the kidneys, symptoms may include:
Although Goodpasture syndrome may cause life-threatening bleeding in the lungs, it usually does not result in long-term lung damage. The most serious consequence of Goodpasture syndrome is kidney failure, which may require either dialysis or a kidney transplant.
Diagnosis of Goodpasture Syndrome
See your doctor at once if you develop the characteristic symptoms of Goodpasture syndrome.
He or she may order the following diagnostic tests:
Urinalysis. High levels of protein and high numbers of red blood cells in urine may indicate kidney damage.
Blood test. A blood sample can be analyzed for the presence of antibodies that attack the lungs and kidneys.
Chest X-ray. Results can identify lung damage. For example, abnormal white patches are associated with lung bleeding.
Biopsy. A small sample of kidney or lung tissue may need to be removed to check for the presence of Goodpasture syndrome antibodies. An analysis of kidney tissue can also identify the extent of any kidney damage.
Treatment of Goodpasture Syndrome
Goodpasture syndrome requires prompt and aggressive treatment in order to:
Fight harmful antibodies
Control fluid buildup
Control high blood pressure
Prevent serious lung and kidney damage
Treatment usually includes oral immunosuppressive drugs such as cyclophosphamide and corticosteroids. These drugs decrease the immune system's production of Goodpasture syndrome antibodies.
In some cases, intravenous corticosteroids may be needed to control bleeding in the lungs.
Depending on the patient's response to therapy, treatment with immunosuppressive drugs may continue for six to 12 months.
Treatment of Goodpasture syndrome also usually includes a procedure called plasmapheresis. This helps remove harmful antibodies from the blood.
During this procedure, about 300 milliliters of blood at a time is drawn from the body and placed in a centrifuge. The centrifuge separates the red and white blood cells from the plasma, the component that contains Goodpasture syndrome antibodies. Then the red and white blood cells are mixed into a plasma substitute and returned to the body.
Usually, plasmapheresis is continued for several weeks.
Goodpasture syndrome may last several weeks or as long as two years.
Until the disease runs its course, some patients may need to be placed on supplemental oxygen or a ventilator. Other patients may require blood transfusions.
Although kidney failure is a common complication of Goodpasture syndrome, less than 30% of surviving patients need long-term dialysis.