Introduction to Autoimmune Disorders of the Lungs
An important function of the immune system is fighting off infections. To do this, the immune system recognizes microorganisms as foreign to the person and produces proteins (antibodies) that join with the microorganisms so they can be removed from the body.
In autoimmune disorders, the body mistakenly reacts against a person's own tissues as if they were foreign and were causing an infection. In autoimmune disorders that involve the lungs, the immune system attacks and damages lung tissue. Different parts of the lungs can be affected and different symptoms may occur. For example, in lupus (systemic lupus erythematosus), the lining of the lungs may be inflamed, causing chest pain, and the blood vessels of the lungs may be inflamed, causing people to cough up blood (hemoptysis). In systemic sclerosis (scleroderma), lung tissue becomes scarred and people have trouble breathing. Autoimmune disorders that affect the lungs also often affect other organs, particularly the kidneys.
Important lung autoimmune disorders include diffuse alveolar hemorrhage, which involves bleeding into the lungs, andpulmonary-renal syndrome, which involves bleeding into the lungs plus kidney dysfunction. Goodpasture syndrome results when a particular autoimmune disorder causes pulmonary-renal syndrome.