Organ-specific autoantibodies have been detected in patients with autoimmune diseases. The relationship between pituitary autoantibodies and lymphocitic hypophysitis has not yet been established and it is not clear if they are a specific serological marker of the disease.
The aim of the present study was to evaluate the prevalence of pituitary autoantibodies in patients affected by autoimmune and nodular thyroid disorders.
803 patients (670 F, 133 M) were enrolled in the study: 387 with Hashimotos thyroiditis (HT) (350 F, 37 M age 42±15 yr), 159 with Gravesdisease (GD) (126 F, 33 M; age 44±14 yr), 37 with toxic uni-multinodular goiter (TNG) (26 F, 11 M; age 54±12 yr) and 220 with non toxic uni-multinodular goiter (NTNG) (168 F, 52 M; age 50±12 yr). 121 normal subjects (98 F, 23 M, age 39±15) served as control group.
Pituitary autoantibodies [anti-neuro- (APA-P) and anti-adenohypophysis (APA-A)] were determined by an immunofluorescence method using sections of pituitary baboon as substrate. Serum dilutions were initially done at 1/10 and, if the sample was positive, at 1/32 and 1/100.
Pituitary autoantibodies were found in 46 patients (11.9%) with HT, 10 patients (6.3%) with GD, 5 patients (2.3%) with NTNG. None of the control group had detectable APA.
These data shows the presence of serological markers of pituitary autoimmunity, determined by a immunofluorescence method, in patients affected by thyroid diseases. In the majority of patients pituitary autoandibodies were detectable at low titer. Further studies are needed to assess pituitary function in patients with pituitary autoantibodies to support the hypothesis that they can play a role in pituitary disfunction.