A wide variety of autocrine/paracrine bioactive signals are able to modulate corticosteroid secretion in the human adrenal gland. These regulatory factors, released in the vicinity of adrenocortical cells by diverse cell types comprising chromaffin cells, nerve terminals, cells of the immune system, endothelial cells, and adipocytes, include neuropeptides, biogenic amines, and cytokines. A growing body of evidence now suggests that paracrine mechanisms may also play an important role in the physiopathology of adrenocortical hyperplasias and tumors responsible for primary adrenal steroid excess. These intra-adrenal regulatory systems, although globally involving the same actors as those observed in the normal gland, display alterations at different levels, which reinforce the capacity of paracrine factors to stimulate the activity of adrenocortical cells. The main modifications in the adrenal local control systems reported by now include hyperplasia of cells producing the paracrine factors and abnormal expression of the latter and their receptors. Because steroid-secreting adrenal neoplasms are independent of the classical endocrine regulatory factors angiotensin II and ACTH, which are respectively suppressed by hyperaldosteronism and hypercortisolism, these lesions have long been considered as autonomous tissues. However, the presence of stimulatory substances within the neoplastic tissues suggests that steroid hypersecretion is driven by autocrine/paracrine loops that should be regarded as promising targets for pharmacological treatments of primary adrenal disorders. This new potential therapeutic approach may constitute an alternative to surgical removal of the lesions that is classically recommended in order to cure steroid excess.
P Saugier-Veber, N Drouot, LM Wolf, JM Kuhn, T Frebourg and H Lefebvre
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is clinically characterized by the presence of two of the three major clinical symptoms: Addison's disease and/or hypoparathyroidism and/or chronic mucocutaneous candidiasis. Because of its autosomal recessive inheritance, this rare disorder constitutes an interesting model for understanding the molecular background of autoimmunity. Recently, mutations in the autoimmune regulator (AIRE-1) gene have been identified in APECED patients. Here we report, in a large French APECED family, the identification of a novel AIRE-1 missense mutation (Pro326Leu) in association with the Arg257Stop mutation which is detected in more than 80% of mutant Finnish AIRE-1 alleles. This Pro326Leu substitution occurs in the first plant homeodomain (PHD)-type zinc-finger domain of the protein which has been identified in a number of nuclear proteins involved in chromatin-mediated transcriptional regulation, such as ATRX, TIF1, KRIP-1 and Mi-2 autoantigen. This mutation highlights the key role of this amino acid in the structure of the PHD domain and confirms that exon 8 constitutes a mutational hotspot.
D Vezzosi, D Cartier, C Régnier, P Otal, A Bennet, F Parmentier, M Plantavid, A Lacroix, H Lefebvre and P Caron
ACTH-independent macronodular adrenocortical hyperplasia (AIMAH) is rare and generally presents as a sporadic disease. We describe a familial case of AIMAH with in vivo and in vitro demonstration of aberrant 5-HT4 and vasopressin adrenal receptors. Two sisters presented with clinical and biological features of mild Cushing’s syndrome with bilateral macronodular adrenal enlargement on computerized tomography (CT)-scan evaluation. In vivo pharmacological tests showed a significant increase in plasma cortisol after terlipressin and metoclopramide administration. Unilateral adrenalectomy was performed in one of these patients. Reverse transcriptase-PCR analysis of the hyperplastic tissue revealed expression of 5-HT4 receptor isoforms (a), (b), (c), (i), and (n), and of vasopressin receptors, V1 and V2. Their father and brother were overweight, had easy bruisability and presented with biological features of subclinical Cushing’s syndrome. CT scan showed moderate adrenal enlargement. In vivo pharmacological screening tests for the detection of adrenal aberrant receptors in the brother were negative. Finally, three out of the two sisters’ children were evaluated. They had neither clinical nor biological features of Cushing’s syndrome. Their adrenal glands were normal on CT-scan evaluation. In vivo evaluation for the detection of aberrant adrenocortical receptors performed in one of these subjects was negative. In conclusion, this study shows that (i) familial AIMAH could be an autosomal dominantly inherited disorder; (ii) aberrant 5-HT4 serotonin and vasopressin receptors can be expressed in familial AIMAH; and (iii) phenotypic expression of familial AIMAH could be varied in a same family and more pronounced in female than in male patients.
Jacques Young, Jérôme Bertherat, Marie Christine Vantyghem, Olivier Chabre, Salima Senoussi, Rita Chadarevian, Frédéric Castinetti and the Compassionalte use Programme
Ketoconazole (KTZ) is one of few available treatments for Cushing’s syndrome (CS). Although KTZ has been associated with severe hepatotoxicity, little information is available about hepatic safety in CS. The aim of this study was to document changes in liver function in patients with CS treated with KTZ.
An observational prospective French cohort study (Compassionate Use Programme (CUP)).
Enrolled patients were stratified into a KTZ-naive cohort and a cohort already treated by another formulation of ketoconazole (KTZ-switch cohort). Liver function markers (alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase, γ-glutamyltransferase and bilirubin) were monitored at regular intervals. Patients with ALT > 3 × ULN (upper limit of normal), total bilirubin > 2 × ULN or both ALP > 2 × ULN and ALT > ULN were considered to have liver injury.
Overall, 108 patients were analysed (47 KTZ-naïve; 61 KTZ-switch). The median KTZ dose was 600 mg/day. Most abnormalities observed were asymptomatic mild increases of liver enzymes. Four patients in the KTZ-naïve cohort (8.5%) and two in the KTZ-switch cohort (3.3%) developed liver injury, considered related to KTZ in three cases (all KTZ-naïve in the first month of treatment). Five patients had mild liver function abnormalities at baseline and two had proven liver metastases. Two patients recovered on discontinuation of KTZ and the remaining patient died of unrelated causes.
These findings highlight the need for close monitoring of liver enzymes especially during the first six months of treatment. Liver enzyme abnormalities usually occurred within four weeks were asymptomatic and could be reversed on timely discontinuation of KTZ.