Background: IgG4-related disease is a rare immune-mediated inflammatory condition associated with extensive multi-organ involvement. Little is known about the epidemiology of pituitary involvement as a part the IgG4-related disease spectrum.
Objectives: We aimed to identify patients with pituitary involvement amongst those with systemic IgG4-related disease, and to compare these individuals to patients with isolated IgG4-related hypophysitis. We also aimed to analyse the utility of serum IgG4 levels in assessing the degree of organ involvement.
Methods: A database was created using pre-existing patient data obtained from electronic patient records. Patients who satisfied the inclusion criteria were systematically screened for anterior and posterior pituitary dysfunction. Screening involved a short hypophysitis symptom screening interview followed by biochemical testing.
Results: A total of 13 patients with systemic IgG4-related disease were successfully screened. An additional 3 patients with isolated IgG4-related hypophysitis were identified. In the group with systemic disease, the female:male ratio was 1.6:1 and the mean age was 59.8 years±12.0 in this cohort. One male was identified to have pituitary involvement, equating to a prevalence of 8%. This patient differed by sex, ethnicity, age, clinical presentation and hormonal profile to those with isolated IgG4-related hypophysitis. We also found a positive trend between serum IgG4 levels and number of organs involved in the disease, although this was not significant.
Conclusion: We conclude that pituitary involvement is a rare but noteworthy clinical manifestation of IgG4-related disease. Biochemical pituitary screening is not justified in all patients with IgG4-related disease, and should only be considered in patients presenting with symptoms of anterior or posterior pituitary dysfunction. We also postulate that isolated IgG4-related hypophysitis may be a distinct clinical entity from systemic IgG4-related disease with pituitary involvement.
Keywords: IgG4, IgG4-related disease, Hypophysitis, Pituitary, Prevalence, Screening