OR02-04 Peripheral Blood Steroid Profiling Discriminates Aldosterone-producing Adenoma Genotypes From Bilateral Primary Aldosteronism

Abstract

Abstract Disclosure: A.F. Turcu: None. C. Lee: None. Z. Salman: None. H. Liu: None. A. Rabbah: None. S.M. Konzen: None. W.E. Rainey: None. T.J. Giordano: None. L. Zhao: None. A. Udager: None. Background: Primary aldosteronism (PA) is dichotomized into 2 major subtypes: unilaterally dominant PA, often caused by aldosterone-producing adenomas (APAs), and bilateral PA (BPA). Adrenal vein sampling (AVS)-guided unilateral adrenalectomy is often curative in patients with APA and offers marked cardiovascular and renal benefits. The diagnosis and subtyping of PA is a complex, multistep process, hindered by expertise and resource limitations. Objective: To develop steroid fingerprints that can distinguish genotype specific APAs from BPA in peripheral blood. Design And Methods: We enrolled 120 patients with PA who underwent AVS in a single tertiary referral center. Liquid-chromatography tandem mass spectrometry was used to simultaneously quantify 17 steroids in adrenal veins (AV) and periphery, both at baseline, and 10-20 min after cosyntropin stimulation. Aldosterone synthase (CYP11B2) immunohistochemistry-guided next generation sequencing was employed to identify aldosterone-driver mutations. Kruskal-Wallis tests were performed for comparison of continuous variables across multiple groups. Receiver operating characteristic (ROC) curves were plotted to discriminate APAs from BPA. Results: The 120 study participants included 75 patients with APA who underwent unilateral adrenalectomy and had documented aldosterone-driver mutations, and 45 patients with BPA. Of patients with APAs, 36 carried somatic mutations in CACNA1D, 24 in ATPase, and 15 in KCNJ5 genes, respectively. Patients with KCNJ5 mutations were younger and most were women. In the dominant AVs, the KCNJ5 group had marked elevations of 18-hydroxycortisol, 18-oxocortisol, aldosterone, and 11-deoxycorticosterone (DOC); conversely, the BB group had the lowest concentrations of mineralocorticoid and androgen precursors, despite comparable cortisol levels across all groups. Similar patterns were observed in peripheral blood. Linear discriminant analysis incorporating all steroids measured in baseline peripheral serum showed areas under the curve (AUC) of 0.98, 0.97, and 0.92 for distinguishing APAs with KCNJ5, ATPase, or CACNA1D mutations, respectively, from BPA. Conclusions: Single-assay steroid profiles measured in peripheral serum can distinguish genotype-specific APAs from BPA. Once validated, such tests might circumvent the need for AVS in large subset of PA patients. Presentation: Thursday, June 15, 2023