Steroid receptor antibodies in autoimmune disorders.

Sera from patients with autoimmune disorders have been analyzed for the presence of antibodies against the estrogen receptor. About 42% of the male and 34% of the female patients had measureable levels of antibody under our assay conditions. However, whereas the male patient population had significantly higher levels of anti-estrogen receptor than normal males, there was no significant difference between female patients and controls. Separation of the estrogen receptor by sucrose gradient centrifugation into the large (9-10S) and small (4S) molecular weight forms demonstrated that only the large form was antigenic, suggesting that the antibodies are not interacting with the steroid binding subunit. The clinical significance of increased levels of antibodies against the estrogen receptor in a percentage of male patients remains to be established.