Eystein Sverre Husebye’s research while affiliated with University of Bergen and other places

The Autoimmune Regulator, AIRE, acts as a transcriptional regulator in the thymus, facilitating ectopic expression of thousands of genes important for the process of negative T-cell selection and immunological tolerance to self. Pathogenic variants in the gene encoding AIRE are causing Autoimmune polyendocrine syndrome type 1 (APS-1), defined by multiorgan autoimmunity and chronic mucocutaneous candidiasis. More recently, Genome Wide Association Studies (GWAS) have also implicated AIRE in several common organ-specific autoimmune diseases including Autoimmune primary adrenal insufficiency, type 1 diabetes and pernicious anemia. We developed a highly sensitive cell-system approach based on HEK293FT cells transfected with AIRE that allowed us to characterise and functionally evaluate the transcriptional potential of genetic variants in the AIRE gene. We confirm that our cell system recapitulates the expression of the vast majority of known AIRE induced genes including well-characterised tissue restricted antigens (TRAs), but also increases the total number of identified AIRE induced genes by an order of magnitude compared to previously published strategies. The approach differentiates between categories of AIRE variants on the transcriptional level, including the nonsense variant p.R257* (near complete loss of function), the p.C311Y variant associated with dominantly inherited APS-1 (severely impaired function), and the polygenic risk variant p.R471C (slightly increased function) linked to common organ-specific autoimmunity. The increased activity of p.R471C compared to wildtype indicates different molecular mechanisms for monogenic and polygenic AIRE related autoimmunity.

Disclosure: M. Aranda Guillen: None. I. Botusan: None. V. Fernando: None. E. Røyrvik: None. A. Bøe Wolff: None. S. Johansson: None. E.S. Husebye: None. S. Bensing: None. O. Kampe: None. D. Eriksson: None. Background: Primary adrenal insufficiency (PAI) is sometimes misdiagnosed as autoimmune Addison's disease (AAD), affecting clinical management and genetic counselling. We tested a polygenic risk score (PRS) for AAD (PRS14AAD) as a tool to reevaluate disease etiology and identify patients misdiagnosed with AAD. Methods: We calculated the PRS14AAD in a cohort of patients diagnosed with AAD but lacking 21-hydroxylase autoantibodies (n=124). Patients with low genetic susceptibility to AAD were selected for whole-genome sequencing to detect potential monogenic causes (n=35). Results: Among the 35 patients, monogenic PAI was diagnosed in 5 (14%) and suspected in 3 additional cases (9%). Three out of the 5 patients diagnosed with monogenic PAI developed the disease in adulthood, indicating late-onset monogenic disease associated with hypomorphic genetic variants. Conclusion: A PRS for AAD can help identify potential monogenic cases, regardless of the age at diagnosis. Early identification of the underlying cause of PAI enables accurate management and correct genetic counselling. Presentation: 6/2/2024

Background: Salivary cortisol (sa-cortisol) and salivary cortisone (sa-cortisone) correlate well with serum cortisol (s-cortisol) but validated reference ranges for healthy individuals are lacking. Objective: To establish cutoff levels for sa-cortisol and cortisone following cosyntropin testing, and assess their diagnostic utility in adrenal insufficiency (AI). Methods: Steroids in saliva were assayed using liquid-chromatography tandem-mass-spectrometry (LCMS/MS) before and after administration of 250µg cosyntropin test in 128 healthy subjects (16 on oral estrogens) and 59 patients with suspected AI, of whom 26 were diagnosed with AI with conventional serum cortisol criteria. The cutoff level for AI was defined as the 2.5th centile in healthy subjects not receiving estrogens. Performance was evaluated by calculating diagnostic accuracy and analyzing receiver operating characteristic-curves. Results: The sa-cortisol cutoff 60 minutes after cosyntropin stimulation was 12.6 nmol/L (accuracy 89%, sensitivity 85%, and specificity 90%). Sa-cortisone and the sum of sa-cortisol and cortisone exhibited poorer diagnostic performance than sa-cortisol. The correlation between sa-cortisol and s-cortisol was best described by a model incorporating two regression lines (R2 = 0.80). Segmented regression analysis identified a breakpoint at sa-cortisol 9.7 nmol/L and s-cortisol 482 nmol/L, likely corresponding to saturation of cortisol binding globulin (CBG). Healthy subjects on oral estrogens demonstrated a linear agreement between s- and sa-cortisol through all measurements. Seventeen healthy subjects repeated the test, with similar outcome, but reproducibility in terms of intraclass coefficient and correlation was poor. Conclusions: Sa-cortisol in cosyntropin-test has high diagnostic accuracy in detecting adrenal insufficiency, and is particularly useful in women on oral estrogens. A sa-cortisol > 12.6 nmol/L assayed with LCMS/MS 60 min after 250µg cosyntropin is normal.

STUDY QUESTION Is it possible to find the cause of primary ovarian insufficiency (POI) in more women by extensive screening? SUMMARY ANSWER Adding next generation sequencing techniques including a POI-associated gene panel, extended whole exome sequencing data, as well as specific autoantibody assays to the recommended diagnostic investigations increased the determination of a potential etiological diagnosis of POI from 11% to 41%. WHAT IS KNOWN ALREADY POI affects ∼1% of women. Clinical presentations and pathogenic mechanisms are heterogeneous and include genetic, autoimmune, and environmental factors, but the underlying etiology remains unknown in the majority of cases. STUDY DESIGN, SIZE, DURATION Prospective cross-sectional study of 100 women with newly diagnosed POI of unknown cause consecutively referred to Haukeland University Hospital, Bergen, Norway, January 2019 to December 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS In addition to standard recommended diagnostic investigations including screening for chromosomal anomalies and premutations in the fragile X mental retardation 1 gene (FMR1) we used whole exome sequencing, including targeted analysis of 103 ovarian-related genes, and assays of autoantibodies against steroid cell antigens. MAIN RESULTS AND THE ROLE OF CHANCE We identified chromosomal aberrations in 8%, FMR1 premutations in 3%, genetic variants related to POI in 16%, and autoimmune POI in 3%. Furthermore in 11% we identified POI associated genetic Variants of unknown signifcance (VUS). A homozygous pathogenic variant in the ZSWIM7 gene (NM_001042697.2) was found in two women, corroborating this as a novel cause of monogenic POI. No associations between phenotypes and genotypes were found. LIMITATIONS, REASONS FOR CAUTION Use of candidate genetic and autoimmune markers limit the possibility to discover new markers. To further investigate the genetic variants, family studies would have been useful. We found a relatively high proportion of genetic variants in women from Africa and lack of genetic diversity in the genomic databases can impact diagnostic accuracy. WIDER IMPLICATIONS OF THE FINDINGS Since no specific clinical or biochemical markers predicted the underlying cause of POI discussion of which tests should be part of diagnostic screening in clinical practice remains open. New technology has altered the availability and effectiveness of genetic testing, and cost-effectiveness analyses are required to aid sustainable diagnostics. STUDY FUNDING/COMPETING INTEREST(S) The study was supported by grants and fellowships from Stiftelsen Kristian Gerhard Jebsen, the Novonordisk Foundation, the Norwegian Research Council, University of Bergen, and the Regional Health Authorities of Western Norway. The authors declare no conflict of interest. TRIAL REGISTRATION NUMBER NCT04082169

Autoimmune polyendocrine syndrome type 1 (APS-1) is caused by mutations in the autoimmune regulator (AIRE) gene. Most patients present with severe chronic mucocutaneous candidiasis and organ-specific autoimmunity from early childhood, but the clinical picture is highly variable. AIRE is crucial for negative selection of T cells, and scrutiny of different patient mutations has previously highlighted many of its molecular mechanisms. In patients with a milder adult-onset phenotype sharing a mutation in the canonical donor splice site of intron 7 (c.879+1G>A), both the predicted altered splicing pattern with loss of exon 7 (AireEx7-/-) and normal full-length AIRE mRNA were found, indicating leaky rather than abolished mRNA splicing. Analysis of a corresponding mouse model demonstrated that the AireEx7-/- mutant had dramatically impaired transcriptional capacity of tissue-specific antigens in medullary thymic epithelial cells but still retained some ability to induce gene expression compared with the complete loss-of-function AireC313X-/- mutant. Our data illustrate an association between AIRE activity and the severity of autoimmune disease, with implications for more common autoimmune diseases associated with AIRE variants, such as primary adrenal insufficiency, pernicious anemia, type 1 diabetes, and rheumatoid arthritis.

Objective Increased prevalence of cardiovascular disease has been reported in autoimmune Addison’s disease (AAD), but pathomechanisms are poorly understood. Design Cross-sectional study. Methods We compared serum levels of 177 cardiovascular and inflammatory biomarkers in 43 patients with AAD at > 18-hour glucocorticoid withdrawal and 43 matched controls, overall and stratified for sex. Biomarker levels were correlated with the frequency of adrenal crises and quality of life (QoL) by AddiQoL-30. Finally, we investigated changes in biomarker levels following 250 µg tetracosactide injection in patients without residual adrenocortical function (RAF) to explore glucocorticoid-independent effects of high ACTH. Results Nineteen biomarkers significantly differed between patients with AAD and controls, all but one (ST1A1) were higher in AAD. Eight biomarkers were significantly higher in female patients compared with controls (IL6, MCP1, GAL9, SPON2, DR4, RAGE, TNFRSF9, PGF), but none differed between male patients and controls. Levels of RAGE correlated with the frequency of adrenal crises (r=0.415, P=0.006) and AddiQoL-30 scores (r=-0.347, P= 0.028), but not after correction for multiple testing. PDL2 and leptin significantly declined 60 minutes after injection of ACTH in AAD without RAF (-0.15 NPX, P=0.0001, and -0.25 NPX, P=0.0003, respectively). Conclusions We show that cardiovascular and inflammatory biomarkers are altered in AAD compared with controls, particularly in women. RAGE might be a marker of disease severity in AAD, associated with more adrenal crises and reduced QoL. High ACTH reduced PDL2 and leptin levels in a glucocorticoid-independent manner but the overall effect on biomarker profiles was small.

Disclosure: I. Botusan: None. K. Berinder: None. P. Methlie: None. T. Upton: None. E. Zavala: None. K. Simunkova: None. D.A. Vassiliadi: None. I. Marinelli: None. G.M. Russell: None. M.A. Grytaas: None. S. Tsagarakis: None. S.L. Lightman: None. E.S. Husebye: None. O. Kampe: None. M. Oksnes: None. S. Bensing: None. Background: The autoimmune attack on the adrenals in AD (Addison’s disease) results in lack of the vital hormones cortisol and aldosterone, rendering AD patients dependent on life-long hormone replacement therapy. Current therapies cannot replicate the physiological well-tuned, circadian and ultradian hormonal oscillations properly, probably contributing to increased mortality, morbidity and reduced quality of life. No established biomarker for treatment monitoring exists hampering treatment optimization. Ambulatory 24-hour dynamic steroid profiling may represent a novel therapy-monitoring tool, providing new insights in different replacement therapy regimes. Aim: We aimed to assess 24-hour profiles of free cortisol and metabolites in patients with AD on different glucocorticoid replacement therapies (GRT) and compare the results with healthy volunteers (HV). Material and methods: The study includes 41 patients with AD on different GRT regimes (hydrocortisone, cortisone acetate, modified release hydrocortisone) and 214 healthy participants. Twenty minute microdialysis fractions were collected ambulatory from abdominal subcutaneous tissue over 24 hours using a novel and portable microdialysis fraction collector (U-RHYTHM). Steroid hormones were analyzed by ultrasensitive liquid chromatography tandem mass spectroscopy (LC-MS/MS). Dynamic biomarkers were used to define hormone parameters in both healthy and hormone-replaced participants, and to assess the “time in range” for patients on GRT compared with the profiles of healthy controls. Results: Free cortisol and cortisone levels were measurable in all AD patients, while 18- hydroxycortisol, and corticosterone were detected only in a few AD patients suggesting the persistence of residual adrenal function. Lower cortisol levels during night were observed in AD compared with controls. Ambulatory 24-hour dynamic steroid profiling revealed marked interindividual variations partially depending on the type of GRT and dosing-regime. Conclusions: The 24-hour profiles of free cortisol and cortisone differs between patients with AD and healthy volunteers. Ambulatory 24-hour microdialysis samplings may provide a novel dynamic tool to monitor GRT in AD providing opportunity for individual dose adjustment. Presentation: Saturday, June 17, 2023

Disclosure: M.A. Grytaas: None. P. Methlie: None. I. Marinelli: None. E. Zavala: None. M. Øksnes: None. T. Upton: None. K. Simunkova: None. D.A. Vassiliadi: None. K. Løvås: None. S. Bensing: None. I. Botusan: None. K. Berinder: None. G.M. Russell: None. G. Ueland: None. O. Kampe: None. S. Tsagarakis: None. S.L. Lightman: None. E.S. Husebye: None. Background: Primary aldosteronism (PA) is the most common cause of secondary hypertension but is grossly underdiagnosed. Early detection, accurate discrimination between unilateral and bilateral PA and appropriate treatment are vital to prevent cardiovascular and renal complications. The current workup however is a cumbersome, multistep process that may not detect dynamic aldosterone variability or nocturnal hypersecretion. Furthermore, subtype determination with adrenal venous sampling is invasive and technically challenging. Novel dynamic 24-hour steroid profiling may represent a major step forward in the diagnostics and subtyping of PA. Aim: To assess 24-hour rhythmicity of aldosterone and metabolites in PA, and to develop a novel dynamic diagnostic tool to discriminate PA from healthy subjects (HS), using tissue microdialysis. Material and methods: Twenty-minute frequency microdialysis fractions were collected over 24 hours from 64 ambulatory patients with PA (26 bilateral, 24 unilateral, 14 with undetermined subtype) using the U-Rhythm sampler followed by multiplex hormone assay liquid chromatography tandem mass spectrometry (LC-MS/MS). Sixteen patients subsequently treated with adrenalectomy for unilateral PA had additional postoperative samplings. Microdialysis samplings from 214 HS were used as controls. We calculated statistical distributions of dynamic biomarkers of abnormality, and developed a machine learning classifier that discriminates PA from HS. Results: Although there were large interindividual variations, PA patients did show a disturbed circadian rhythmicity of aldosterone compared with HS, including some with multiple very high ultradian spikes. Unilateral PA had higher aldosterone spikes and more disturbed rhythmicity compared with bilateral PA. A profound reduction of aldosterone levels and normalisation of rhythmicity was seen post adrenalectomy. Applying a Random Forest classifier in a subgroup of 20 PA patients, 82% specificity and 85% sensibility were achieved to discriminate PA from HS. Our analysis also suggests 18-hydroxycortisol as the most discriminative dynamic biomarker. Conclusions: We demonstrate for the first time circadian and ultradian rhythms of aldosterone in a large cohort of PA compared with HS. Based on our preliminary results, dynamic 24-hour samplings may provide a novel method for diagnosing and subtyping PA, and assess biochemical cure after adrenalectomy. Presentation: Thursday, June 15, 2023