[Clinical study of anti-phospholipid antibody in patients with sarcoidosis]

Serum antibodies against five types of phospholipids were measured by enzyme-linked immunosorbent assay (ELISA) in 55 patients with sarcoidosis. In 21 cases (38%), either IgG antibodies or IgM antibodies were detected. These antibodies were thought to mainly be infective type. This positive rate was significantly higher than that (7%) of the control group (70 cases) (p < 0.01). As to the immunoglobulin classes, 5 cases had IgG antibodies only, 11 cases had IgM antibodies only, and 5 cases had both IgG and IgM antibodies. No correlation was observed between the occurrence of anti-phospholipid antibodies (APL-Ab) and disease activity of sarcoidosis. Significant correlations were found between the occurrence of APL-Ab and skin lesions, many extrathoracic organ lesions and the persistence of abnormal chest X-ray findings for over 2 years and 5 years. From these data, it is suggested that the presence of APL-Ab is associated with prolonged disease activity of sarcoidosis.