Prevalence of autoimmune disease in patients with prolactinomas and non-functioning pituitary adenomas.

ABSTRACT

PURPOSE: Prolactin can affect autoimmune response and evidence suggests that hyperprolactinemia can primarily precipitate autoimmunity. We postulate that patients with prolactinomas are more prone to autoimmune disease (AID). METHODS: We conducted a retrospective case-control study comparing prevalence of AID in 100 prolactinoma patients (PRL-P, cases) and 100 age- and gender-matched non-functioning pituitary adenoma patients (NFPA-P, controls) assessed at the Neuroendocrine Clinics of the McGill University Health Centre between January 2005 and December 2014. Comparisons were done using a conditional logistic regression (CLR) analysis. Multiple imputation was used to account for missing data values. RESULTS: Sixty-eight women and 32 men were in each group. Median age was 37 years for PRL-P and 46 years for NFPA-P. AID was diagnosed in 28/100 cases and 16/100 controls. Autoimmune thyroid disease was the most common AID reported in both groups, representing 70 and 61% of the AID diagnoses respectively. CLR analysis revealed a multiplicative interaction effect between AID prevalence and age (p 0.004). Odds ratios for AID in PRL-P compared to NFPA-P increase with age and become significant at age 43, reaching 4.17 (95% CI 1.26, 13.82) at age 45 and 8.09 (95% CI 1.96, 33.43) at age 50 (p 0.05). CONCLUSION: Our data showed a higher prevalence of AID in both PRL-P and NFPA-P than in a reference population. In both groups, prevalence of AID increased with age, given a multiplicative interaction effect. A significant higher prevalence of autoimmunity in PRL-P compared with NFPA-P occurs after age 43. These associations may have significant implications for the management of prolactinoma patients.