Goodpasture's syndrome is a rare disease involving the kidneys and lungs, in some cases even at the same time. It is an autoimmune disease characterized by a reaction of the body's defense system (immune system) that mistakenly targets parts of one's body.
In Goodpasture syndrome, the immune system produces autoantibodies against the basement membrane collagen of the glomeruli in the lungs and kidneys (anti-GBM antibodies).
Goodpasture's syndrome is characterized by the association of:
- presence of anti-MBG antibodies
- glomerulonephritis, inflammation of the kidney glomeruli, small groups of blood vessels that help the kidneys in their blood-filtering function
- pulmonary haemorrhage (bleeding in the lungs)
Factors that can trigger the production of anti-GBM antibodies are, for example, substances present in the environment, such as tobacco smoke and some solvents, or even upper respiratory tract infections or pneumonia of viral origin (less common).
Goodpasture syndrome has an "incidence of 0.5-1 case per million population per year. It is more common in Caucasian populations and in males than in females. It can affect people of all ages, although there are two peaks of incidence, between 20 and 30 years and between 60 and 70 years of life. The incidence is higher in spring-summer.Goodpasture's syndrome is treated with immunosuppressive drugs, corticosteroids and with plasmapheresis (a therapeutic procedure that allows the separation of the liquid component from the cellular component of the blood).
Goodpasture's syndrome is included in the "list of rare diseases defined by the" Istituto Superiore di Sanità (code RG0060). From the homepage of the National Center for Rare Diseases of the Istituto Superiore di Sanità, it is possible to access the rare diseases portal (www.malattierare.gov.it) and consult the complete list of clinical centers.
If not diagnosed and treated quickly, Goodpasture's syndrome is fatal.
The general practitioner indicates the most appropriate specialist to consult. The referring doctors specialize in diseases of the respiratory system (pulmonologist) and kidney (nephrologist).
Symptoms of Goodpasture's syndrome initially may include:
- He retched
- weight decrease
Symptoms of kidney damage include:
- blood in the urine or foamy urine
- swelling (edema) in the legs
- hypertension (high blood pressure)
Pulmonary symptoms may appear weeks or years earlier than those caused by kidney damage and include:
- coughing up blood (hemoptysis)
The progression of symptoms can be very rapid and severe enough to cause lung failure (severe difficulty in breathing, wheezing and a bluish discoloration of the skin) which can lead to death.
The causes of Goodpasture's syndrome are not fully known.
Smoking or the use of hair dyes as well as exposure to hydrocarbon fumes, metal powders and certain substances, such as cocaine, can be triggers of this condition in genetically predisposed people.
In addition, upper respiratory tract infections or viral pneumonia can cause the production of autoantibodies, antibodies to MBG, which react against collagen, a protein found in the basement membrane of the lungs and kidneys. The basement membrane is a thin layer of cells which in the renal glomerulus plays, together with other structures, the role of filter for the blood, and in the pulmonary alveolus it allows the exchange of carbon dioxide with oxygen. Anti-MBG antibodies , by binding to the collagen of the renal and pulmonary basement membrane, they trigger an inflammatory state that produces damage to the pulmonary alveoli and renal glomeruli.
To diagnose Goodpasture syndrome, your doctor will ask you to perform the following tests:
- urine analysis, to detect the presence of protein or blood in the urine. A high red blood cell count and high protein levels in the urine indicate kidney damage. The urine sample should be collected in a suitable container
- blood tests, reveal the possible presence of anti-MBG antibodies
- chest x-ray, will show abnormal white patches due to pulmonary haemorrhage
- biopsy, procedure that involves the removal of a small fragment of kidney tissue to examine it under the microscopic. The examination is performed to obtain more detailed information on the extent of the damage and the possibility of recovery of renal function
Goodpasture's syndrome is usually treated with:
- immunosuppressive drugs, such as cyclophosphamide, to stop the immune system from making antibodies. In patients who have serious side effects resulting from the use of cyclophosphamide, rituximab is used, which suppresses the immune system
- corticosteroid medications, such as methylprednisolone, to suppress the autoimmune response
- plasmapheresis, procedure which, in this case, aims to remove antibodies from the blood. The procedure uses a machine to separate the blood cells from the plasma (anti-GBM antibodies remain in the plasma). The separated blood cells will then be administered to the person being treated
Plasmapheresis usually takes several weeks; immunosuppressive drugs can be administered for 6-12 months, depending on the personal response to therapy. The treatment achieves a one-year survival of 75% of cases.
In most cases, bleeding in the lungs stops and no permanent lung damage occurs, but assisted ventilation may be required in the event of pulmonary haemorrhage to facilitate gas exchange.
In case of severe kidney damage, dialysis or kidney transplantation may be required. Dialysis is a procedure performed with the help of specific equipment which, by passing the blood through a filter, removes the waste produced by the body.
National Institutes of Health (NIH). National Institute of Diabetes and Digestive and Kidney Diseases. Anti-GBM (Goodpasture's) Disease (English)
The European Rare Kidney Disease Reference Network (ERKNet). Goodpasture's syndrome and anti-basement membrane antibody glomerulonephritis