Brain structure in autoimmune Addison's disease.

Long-term disturbances in cortisol levels might affect brain structure in individuals with autoimmune Addison's disease (AAD). This study investigated gray and white matter brain structure in a cohort of young adults with AAD. T1- and diffusion-weighted images were acquired for 52 individuals with AAD and 70 healthy controls, aged 19-43 years, using magnetic resonance imaging. Groups were compared on cortical thickness, surface area, cortical gray matter volume, subcortical volume (FreeSurfer), and white matter microstructure (FSL tract-based spatial statistics). Individuals with AAD had 4.3% smaller total brain volume. Correcting for head size, we did not find any regional structural differences, apart from reduced volume of the right superior parietal cortex in males with AAD. Within the patient group, a higher glucocorticoid (GC) replacement dose was associated with smaller total brain volume and smaller volume of the left lingual gyrus, left rostral anterior cingulate cortex, and right supramarginal gyrus. With the exception of smaller total brain volume and potential sensitivity of the parietal cortex to GC disturbances in men, brain structure seems relatively unaffected in young adults with AAD. However, the association between GC replacement dose and reduced brain volume may be reason for concern and requires follow-up study.

A polygenic risk score to help discriminate primary adrenal insufficiency of different etiologies.

BACKGROUND: Autoimmune Addison's disease (AAD) is the most common cause of primary adrenal insufficiency (PAI). Despite its exceptionally high heritability, tools to estimate disease susceptibility in individual patients are lacking. We hypothesized that polygenic risk score (PRS) for AAD could help investigate PAI pathogenesis in pediatric patients. METHODS: We here constructed and evaluated a PRS for AAD in 1223 seropositive cases and 4097 controls. To test its clinical utility, we reevaluated 18 pediatric patients, whose whole genome we also sequenced. We next explored the individual PRS in more than 120 seronegative patients with idiopathic PAI. RESULTS: The genetic susceptibility to AAD-quantified using PRS-was on average 1.5 standard deviations (SD) higher in patients compared with healthy controls (p < 2e - 16), and 1.2 SD higher in the young patients compared with the old (p = 3e - 4). Using the novel PRS, we searched for pediatric patients with strikingly low AAD susceptibility and identified cases of monogenic PAI, previously misdiagnosed as AAD. By stratifying seronegative adult patients by autoimmune comorbidities and disease duration we could delineate subgroups of PRS suggesting various disease etiologies. CONCLUSIONS: The PRS performed well for case-control differentiation and susceptibility estimation in individual patients. Remarkably, a PRS for AAD holds promise as a means to detect disease etiologies other than autoimmunity.

Increased Resting-State Functional Connectivity in Patients With Autoimmune Addison Disease.

CONTEXT: Individuals with autoimmune Addison disease (AAD) take replacement medication for the lack of adrenal-derived glucocorticoid (GC) and mineralocorticoid hormones from diagnosis. The brain is highly sensitive to these hormones, but the consequence of having AAD for brain health has not been widely addressed. OBJECTIVE: The present study compared resting-state functional connectivity (rs-fc) of the brain between individuals with AAD and healthy controls. METHODS: Fifty-seven patients with AAD (33 female) and 69 healthy controls (39 female), aged 19 to 43 years were scanned with 3-T magnetic resonance imaging (MRI). RESULTS: Independent component and subsequent dual regression analyses revealed that individuals with AAD had stronger rs-fc compared to controls in 3 networks: the bilateral orbitofrontal cortex (OFC), the left medial visual and left posterior default mode network. A higher GC replacement dose was associated with stronger rs-fc in a small part of the left OFC in patients. We did not find any clear associations between rs-fc and executive functions or mental fatigue. CONCLUSION: Our results suggest that having AAD affects the baseline functional organization of the brain and that current treatment strategies of AAD may be one risk factor.