It has been suggested that the humoral immune system plays a part in the pathogenesis of pulmonary fibrosis. Although circulating autoantibodies to lung protein(s) have been suggested, few lung proteins have been characterised. The purpose of this study is to determine the antigen recognised by serum of a patient with pulmonary fibrosis associated with dermatomyositis.
To accomplish this, anti-small airway epithelial cell (SAEC) antibody in a patient's serum was evaluated using a western immunoblot.
An autoantibody against SAEC was found, and the antigen had a molecular weight of 62 kDa. Using the patient's serum, clones from the normal lung cDNA library were screened and demonstrated that anti-SAEC antibody in the patient's serum was against ADAM (A disintegrin and metalloprotease) 10.
This is the first report that demonstrates the existence of anti-ADAM 10 antibody in a patient with pulmonary fibrosis associated with dermatomyositis.