Immunohistochemical Analysis of CYP11B2, CYP11B1 and β-catenin Helps Subtyping and Relates With Clinical Characteristics of Unilateral Primary Aldosteronism

Abstract

Background: Primary aldosteronism is caused by aldosterone overproduction. While conventional hematoxylin-eosin staining can demonstrate morphological abnormality, it cannot provide any functional histopathological information. We aimed to identify the diagnostic, functional and prognostic value of CYP11B2, CYP11B1, and β-catenin immunostaining in unilateral hyperaldosteronism.Method: A total of 134 patients with unilateral hyperaldosteronism were recruited in our study. The expression of CYP11B2, CYP11B1, and β-catenin was evaluated semiquantitatively on 134 patients’ sections using immunohistochemistry technology and the relationship with clinical data was assessed.Results: Patients were classified into four subtypes based on CYP11B2 staining as below: (1)118 patients with unilateral single aldosterone-producing adenoma (APA), (2)11 with unilateral multiple APA, (3)four with aldosterone-producing cell cluster (APCC), and (4)one with an undefined source. Adjusted CYP11B2 H-score was correlated with serum aldosterone, aldosterone to renin ratio (ARR), and serum potassium. In the abnormal β-catenin staining group, hypertension duration, aldosterone, ARR, cortisol, tumor diameter, tumor area, and CYP11B2 H-score were significantly higher than those of the wild-type group. Serum potassium level was significantly lower in the abnormal β-catenin staining group. Age, gender, BMI, family history of hypertension, adjusted CYP11B2 and CYP11B1 H-scores differed significantly between complete clinical success and incomplete clinical success groups. Age, gender and family history of hypertension were independently associated with complete clinical success based on multivariate logistic regression analysis.Conclusion: CYP11B2 immunostaining could improve the differential diagnosis of unilateral hyperaldosteronism. Adjusted CYP11B2 H-score could be used as a histopathological marker to reflect the severity of unilateral APA. Dysregulation of Wnt/β-catenin signaling and impaired β-catenin degradation may provoke the proliferation and enhance the steroidogenic ability of APA tumor cells, indicating that the Wnt pathway might be a potential, actionable, therapeutic target in the treatment of hyperaldosteronism. Age, sex and family history of hypertension were independent predictors of clinical outcome after adrenalectomy for unilateral hyperaldosteronism.

Adrenalectomy for primary aldosteronism and its related surgical characteristics

“…PRKACA mutates found in APAs lead to persistent activation of the cAMP/PKA signaling pathway, resulting in dysregulation of cell proliferation ( 13 ). Somatic mutate of the CTNNB1 gene, which encodes a β-catenin, have been identified in APA, and the affected WNT/β-catenin signaling pathway is essential for the regulation of proliferation, differentiation and tumorigenesis in the adrenal cortex ( 14 ). However, the potential mechanism by which mutations in the CTNNB1 gene lead to aldosterone overproduction is unclear.…”

“…Hematoxylin-eosin (HE) staining, routinely performed in the pathology laboratory, provides only morphological information, but it is not suitable for functional histopathological analysis and cannot determine the source of excess aldosterone ( 14 ). Immunohistochemical staining for CYP11B2, a key enzyme involved in aldosterone synthesis present in the zona glomerulosa, is important for the diagnosis of potential sources of excess aldosterone production and pathology in PA.…”

Role of adrenal venous sampling in the differential diagnosis and treatment protocol of ACTH-independent Cushing’s syndrome with bilateral adrenal lesions

“…Immunohistochemistry was performed according to the standard histopathological protocol described in a previous study 7 . Based on the differential expression of two subtypes of 11-hydroxylase (CYP11B1 8 and CYP11B2 9 ) in distinguishing aldosterone-producing adenoma and cortisol-producing adenoma, we applied immunostaining for CYP11B1 (rat monoclonal, 1:200; Merck Millipore, MABS502, RRID: AB_2650563) and CYP11B2 (mouse monoclonal, 1:200; Merck Millipore, MABS1251, RRID: AB_2650562) to help verify the differential diagnosis of AICS. A standard avidin-biotin-peroxidase complex technique was used to demonstrate primary antibody binding (Vector pk-7200; Vector Laboratories, Inc., Burlingame, CA, United States).…”

The Entity of Connshing Syndrome: Primary Aldosteronism with Autonomous Cortisol Secretion

“…Traditionally, PA is associated with an adrenal tumour, bilateral adrenal hyperplasia, adrenal cortex carcinoma and ectopic aldosterone production, but benign adrenal sources are described as aldosteronona (solitary tumour), aldosterone-producing nodule or multiple micronodules (non-classical type), respective bilateral adrenal disease; for instance, unilateral PA may underline a unilateral single or multiple aldosterone-producing adenoma or an aldosterone-producing cell cluster [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 127 , 128 , 129 , 130 , 131 , 135 , 136 ].…”