Defective yeast opsonisation of serum in sarcoidosis.

We have studied the opsonising ability of the sera of 49 patients with sarcoidosis. The serum of 11 (22%) patients was defective in this ability, whereas only two (4%) of 46 clinic control subjects and three (7%) of 43 laboratory control subjects showed this defect. The difference between the prevalence of the defect in sarcoidosis and the control groups was statistically significant (p less than 0.01). Although the patients with sarcoidosis who had this defect tended to have pulmonary infiltration, this relationship was not statistically significant. Similarly, there was no correlation between the activity of sarcoidosis and this defect, although there was a significant (p less than 0.05) relationship between the opsonising defect and the persistence of circulating immune complexes. Serum opsonisation is a genetically linked host defense mechanism. Our findings suggest that the presence of this serum defect may render a person more susceptible to sarcoidosis.