Presence of anti-pituitary hormone antibodies in patients with empty sella syndrome and pituitary tumours.

OBJECTIVE: We evaluated the presence of anti-pituitary hormone autoantibodies (APHA) in patients with primary empty sella syndrome and pituitary tumours and examined the correlation of positive antibodies with the hormonal deficiencies. DESIGN: Case-control, retrospective study. PATIENTS: Eleven patients were identified with primary empty sella syndrome or a pituitary tumour by magnetic resonance imaging or computed tomography scanning. Six healthy, normal subjects without evidence of a pituitary problem served as the control group. MEASUREMENTS: Anti-pituitary hormone autoantibodies against purified pituitary hormones were measured in all subjects utilizing an immunoblotting technique. All patients with pituitary disease had their medical records reviewed for any hormonal evaluation. RESULTS: All of the normal subjects were negative for antipituitary hormone antibodies. Forty-five per cent of patients with pituitary disease (pituitary tumours or primary empty sella syndrome) had positive antipitutary hormone antibodies. Of the five patients with positive antipituitary hormone antibodies, anti-ACTH antibodies were the most common (5/5) followed by anti-TSH and anti-GH antibodies (2/5 for each). The hormonal deficiencies failed to correspond with the antipituitary hormone antibodies. Anti-ACTH antibody had a sensitivity of 50% with a specificity of 56%. The anti-TSH antibody yielded a sensitivity of 67% with a specificity of 100%. The anti-FSH/LH antibody reported a 0% sensitivity. CONCLUSIONS: Detection of antipituitary hormone antibody was unable to discriminate between empty sella syndrome and pituitary tumours. The presence of these antipituitary hormone antibodies were neither specific for, nor predictive of, the endocrine deficiencies.