Goodpasture syndrome is a rare autoimmune disease characterised by lung haemorrhage, rapid destruction of the kidney and the presence of antibodies to glomerular basement membrane (GBM).
The GBM antigen responsible for this disease is a component of the non-collagenous domain (NC1) of the alpha-3 chain of collagen type IV. Patients with Goodpasture syndrome develop antibodies to GBM which attack collagen in the alveoli in the lungs and the glomeruli of the kidney. As there are several other autoimmune diseases which may present with similar symptoms, detection of anti-GBM antibodies is a useful aid in the differentiation between these diseases.
Deposits of antibodies in the basement membrane break down collagen and interrupt membrane integrity. This causes leakage of blood and a rapid inflammatory response leading to lung haemorrhage and kidney damage. Patients with Goodpasture syndrome experience a rapid progression to renal failure and death if the disease is not recognised and treated early. Because of the vagueness of early symptoms and rapid progression of the disease, diagnosis is often not reached until very late in the course of the disease. Like many autoimmune diseases, Goodpasture’s syndrome responds well to treatment with corticosteroids and immunosuppressants. The concentration of anti-GBM antibodies in the blood may be reduced by plasmapheresis to remove blood plasma and replace a portion of the plasma with an isotonic salt and protein solution.
As with many autoimmune conditions, the precise cause of Goodpasture’s Syndrome is not yet known. It is believed to be a type II hypersensitivity reaction to Goodpasture’s antigens on the basement membrane of the glomerulus of the kidneys and the pulmonary alveolus. Goodpasture syndrome is a very rare condition and the incidence in Europe, is between 1 in 1,000,000 and 1 in 2,000,000.