Association of primary aldosteronism with chronic thyroiditis

Autoimmune Implications in a Patient with Graves' Hyperthyroidism, Pre-eclampsia with Severe Features, and Primary Aldosteronism

Background and Objectives: Graves' disease (GD) and primary aldosteronism (PA) are two pathologies that can cause significant morbidity and mortality. GD is mediated by autoantibodies, and recent studies have shown autoantibody involvement in the pathophysiology behind both PA and pre-eclampsia. The coexistence of GD and PA, however, is reportedly rare. This report describes a unique case of Graves' hyperthyroidism and concomitant PA in a patient with a history of pre-eclampsia with severe features. Case Presentation: The patient presented at 17 weeks pregnancy with mild hyperthyroidism, negative TSH receptor antibodies, and a low level of thyroid-stimulating immunoglobulins (TSI). Her TSH became detectable with normal thyroid hormone levels, and therefore, no anti-thyroid medication was administered. At 34 weeks she developed pre-eclampsia with severe features, and a healthy child was delivered; her TSH returned to normal. Seven months after delivery, she presented emergently with severe hyperthyroidism, hypertensive crisis, and a serum potassium of 2.5 mmol/L. Her hypertension was uncontrolled on multiple anti-hypertensives. Both TSI and TSH receptor antibodies were negative. The aldosterone(ng/dL)/renin(ng/mL/h ratio was (13/0.06) = 216.7, and abdominal CT imaging demonstrated normal adrenal glands; thus, a diagnosis of PA was made. Her blood pressure was subsequently controlled with only spironolactone at 50 mg 2xday. Methimazole was started but discontinued because of an allergic reaction. Consequently, a thyroidectomy was performed, and pathology revealed Graves' disease. The patient remained well on levothyroxine at 125 mcg/day and spironolactone at 50 mg 2xday three months after the thyroidectomy. Conclusions: This patient manifested severe GD with antibodies undetectable by conventional TSI and TSH receptor assays and accelerated hypertension from PA simultaneously. These conditions were successfully treated separately by spironolactone and thyroidectomy. Autoimmune PA was considered likely given the clinical picture. The diagnosis of PA should be considered in hypertension with GD.

First Evidence of Mineralocorticoid Receptor Gene and Protein Expression in Rat and Human Thyroid Tissues and Cell Cultures

Aldosterone (Aldo) exerts its action through binding with the mineralocorticoid receptor (MR). Clinically, a link between primary aldosteronism (PA) and thyroid diseases has been hypothesised. However, the presence and activity of MR on the thyroid have not yet been demonstrated. We investigated the gene/protein expression and activation of MR in primary thyroid cell cultures (normal rat thyroid [FRTL-5] and human papillary thyroid cancer [PTC] cell lines, BCPAP and K1) through qRT-PCR analysis, immunofluorescence, and confocal microscopy. We also studied the effects of Aldo on thyroid-specific and inflammation genes in vitro. Paired human normal and neoplastic thyroid tissues were also studied. We demonstrated both gene and protein expression and activation of MR in normal rat thyroid and human PTC lines. Incubation with Aldo induced an acute increase in IL-6 expression in both the FRTL-5 and BCPAP lines, which was antagonised by spironolactone, and an acute and late upregulation of thyroid-specific genes in FRTL-5. MR was also expressed at both gene and protein levels in normal human thyroid tissues and in PTC, with a progressive decline during neoplastic tumourigenesis, particularly in more aggressive histotypes. We present the first evidence of MR gene and protein expression in both normal and pathological thyroid cells and tissues. We have shown that MR is present and functionally activated in thyroid tissue. Binding of Aldo to MR induces the expression of inflammatory and thyroid-specific genes, and the thyroid may thus be considered a novel mineralocorticoid target tissue.

Association of Papillary Thyroid Carcinoma with Primary Aldosteronism

Objective The association of primary aldosteronism (PA) with thyroid disease has already been suggested. The aim of this study was to examine the presence of PA in patients with papillary thyroid carcinoma (PC) and to characterize such PC patients with PA. Methods We examined the presence of PA in 81 consecutive patients with PC, whose random sitting blood pressure (BP) was ≥140/90 mmHg in the office (n= 68), who had an incidental adrenal tumor or adrenal enlargement (n=9), or who showed hypokalemia (n=4). Thirty-one of these 81 patients had been treated with anti-hypertensive drugs. The plasma aldosterone concentration (PAC) and plasma renin activity (PRA) were first measured before operation in 16 patients and after operation in 65 patients. PA was diagnosed according to the guidelines of the Japan Endocrine Society. Results Forty patients with PC with a random PAC/PRA ratio of over 200 were subjected to a further study (12 of these patients had been treated with anti-hypertensive drugs). Ultimately, 15 patients with PC were diagnosed with PA. Adrenal venous sampling was done in 9 out of 15 patients with PC associated with PA. No patients were diagnosed as having unilateral lesions. Among the 15 patients, white-coat hypertension was observed in 5 patients, and normotension was observed in 1 patient. Conclusion These findings suggest that the prevalence of PA may be high among patients with PC. An active examination is needed to detect PA, as its signs and symptoms may be mild in patients with PC associated with hypertension.

Aldosterone in Gynecology and Its Involvement on the Risk of Hypertension in Pregnancy

Aldosterone is the main mineralocorticoid hormone, responsible of the regulation of fluid and electrolyte balance and blood pressure. It acts also as a pro-inflammatory factor responsible of an increased cardiovascular risk, independent from blood pressure values. After the discovery of mineralocorticoid receptor (MR) in mononuclear leukocytes, further studies supported its role in inflammatory and even autoimmune mechanisms underlying several diseases. In particular, recent studies reported a possible involvement of aldosterone in some gynecological conditions and diseases, characterized by inflammation, hypertension and increased cardio-metabolic risk, such as use of hormonal contraceptives, preeclampsia, polycystic ovary syndrome, uterine fibroids, and endometriosis. The aim of this mini-review is to report the possible involvement of aldosterone in all these gynecological conditions, suggesting different pathogenetic mechanisms and new target treatments of MR blockers for these diseases.

The influence of thyroid autoimmunity on embryo quality in women undergoing assisted reproductive technology

The influence of thyroid autoimmunity in assisted reproductive technology (ART) outcome in euthyroid women is still controversial. In this study, we retrospectively evaluated embryo quality in 123 euthyroid women undergoing ART with or without thyroid autoantibodies (TAA). Embryo quality was assessed in 119 embryos of 29 infertile patients with TAA and in 394 embryos of 94 infertile patients without TAA. Our results showed not statistically significant differences in age, body mass index, anti-Müllerian hormone, follicle stimulating hormone, free triiodothyronine, and free thyroxine levels between cases and controls. Thyroid stimulating hormone was within the normal range, but significantly higher in TAA patients compared with the controls (2.4 ± 0.8 vs. 2 ± 0.9 mIU/L, respectively, p < .01). The number of oocytes picked up and fertilized was comparable between the two groups. Embryo quality was significantly impaired in women with at least one autoantibody (p < .001). Implantation rate, pregnancy rate, and ongoing pregnancy rate were comparable in the two groups. These results suggest a negative impact of thyroid autoimmunity in embryo quality in women undergoing ART even when thyroid function is normal.

Evaluation of angiotensin II type-1 receptor antibodies in primary aldosteronism and further considerations about their possible pathogenetic role

Angiotensin II type-1 receptor autoantibodies (AT1RAb) have been involved in the genesis of primary aldosteronism (PA), both in aldosterone-producing adenoma (APA) and in idiopathic hyperaldosteronism (IHA). In this study, we evaluated the titer of AT1RAb in 44 PA patients (15 with APA and 29 with IHA) compared with 18 normotensive healthy controls who were matched for gender and age. In 17 PA patients (6 APA and 11 IHA) the titer was evaluated under mineralocorticoid receptor (MR) antagonist treatment. We found that PA patients had a significantly higher titer of AT1RAb compared with controls (median values 33 [IQR 15.6] IU/mL vs 17.5 [IQR 10.8] IU/mL, respectively; P < 0.0001). No significant difference of the AT1RAb titer was reported among PA patients, subdivided according to the subtypes and the concomitant MR antagonist therapy. No significant correlation was detected between age, gender, BMI, blood pressure values, baseline aldosterone, ARR, and the AT1RAb titer of all patients enrolled. Our data confirm an increased titer of AT1RAb in both subtypes of PA, independently from the concomitant use of MR antagonists and clinical/biochemical characteristics of PA patients. The small sample of patients and the relatively short time of treatment could have influenced these results. Moreover, the ELISA assay fails to evaluate the bioactivity of AT1RAb. Further studies should evaluate if the subtype, the clinical/biochemical recovery of PA, or both, influence the pathogenetic role of AT1RAb. The possible autoimmune pathogenesis and reversal effect with AT1R blocker treatment in PA patients with AT1RAb positivity is intriguing and requires further study.