Goodpasture syndrome (GPS; also known as Goodpasture’s disease, anti-glomerular basement antibody disease, or anti-GBM disease) is a rareautoimmune disease in which antibodies attack the basement membrane in lungs and kidneys, leading to bleeding from the lungs and to kidney failure. It is thought to attack the alpha-3 subunit of type IV collagen, which has therefore been referred to as Goodpasture's antigen. Goodpasture's syndrome may quickly result in permanent lung and kidney damage, often leading to death. It is treated with immunosuppressant drugs such as corticosteroids and cyclophosphamide, and with plasmapheresis, in which the antibodies are removed from the blood.
Its precise cause is unknown, but it is believed that an insult to the blood vessels taking blood from and to the lungs is required in order to allow the anti-GBM antibodies to come into contact with the alveoli. Examples of such an insult include:
Exposure to organic solvents (e.g. chloroform) or hydrocarbons.
GPS causes the abnormal production of anti-GBM antibodies, by the plasma cells of the blood. The anti-GBM antibodies attack the alveoli and glomeruli basement membranes. These antibodies bind their reactive epitopes to the basement membranes and activate the complement cascade, leading to the death of tagged cells.T cells are also implicated. It is generally considered a type II hypersensitivity reaction.
The diagnosis of GPS is often difficult, as numerous other diseases can cause the various manifestations of the condition and the condition itself is uncommonly rare. The most accurate means of achieving the diagnosis is testing the affected tissues by means of a biopsy, especially the kidney as it is the best studied-organ for obtaining a sample, for the presence of anti-GBM antibodies. On top of the anti-GBM antibodies implicated in the disease about one in three of those affected also have cytoplasmic antineutrophilic antibodies in their bloodstream, which often pre-dates the anti-GBM antibodies by about a few months or even years. The later the disease is diagnosed the worse the outcome is for the affected person.
The major mainstay of treatment for GPS is plasmapheresis, a procedure in which the affected person's blood is sent through a centrifuge and the various components separated based on weight. The plasma, clear liquid part of the blood, contains the anti-GBM antibodies that attacks the affected person's lungs and kidneys and is filtered out. The other parts of the blood, that is, the red blood cells, white blood cells and platelets are recycled back and given intravenously as a replacement fluid. On top of this most individuals affected by the disease need to be treated with immunosuppressants (drugs that suppress the functioning of the immune system), especially cyclophosphamide, prednisone and rituximab, to prevent the formation of new anti-GBM antibodies so as to prevent further damage to the kidneys and lungs. Other less toxic immunosuppressants like azathioprine may be used to maintain remission.
Without treatment virtually every affected person will end up dying from either advanced kidney failure or lung hemorrhages. With treatment the 5-year survival rate is >80% and fewer than 30% of affected individuals require long-term dialysis. Likewise the median survival time is about 5.93 years in Australia and New Zealand.
GPS is rare affecting about 0.5-1.8 per million people per year in Europe and Asia. It is also unusual among autoimmune diseases in that it is more common in males than in females and is also less common in blacks than whites but more common in the Māori people of New Zealand. The peak age ranges for the onset of the disease are 20-30 and 60–70 years.