Rapid decrease in adrenal responsiveness to ACTH stimulation after successful pituitary surgery in patients with Cushing's disease

Dual effects of 9-cis retinoic acid on ACTH-dependent hyperplastic adrenal tissues

Retinoids play a pivotal role in adrenal development and differentiation. Recent clinical trials revealed therapeutic potential of both all-trans and 9-cis retinoic acid in patients with cortisol excess due to a pituitary ACTH-secreting adenoma and indicated that retinoids might act also on the adrenal. Aim of the present study was to evaluate the effect of 9-cis retinoic acid on adrenals from patients with ACTH-dependent Cushing’s syndrome. Adrenal specimens from six patients with Cushing’s disease were incubated with 10 nM–1 µM 9-cis retinoic acid with and without 10 nM ACTH. Cortisol secretion was measured by immunoassay and expression of genes involved in steroidogenesis as well as retinoic acid action were evaluated by real-time RT-PCR. Incubation with 10–100 nM 9-cis retinoic acid increased spontaneous cortisol secretion and expression of STAR and CYP17A. On the other hand, in wells treated with ACTH, 9-cis retinoic acid markedly diminished ACTH receptor upregulation and no stimulatory effect on cortisol secretion or steroidogenic enzyme synthesis was observed. ACTH itself increased ligand-induced retinoic acid receptor expression, possibly enhancing sensitivity to retinoic acid. Our findings indicate that the effect of 9-cis retinoic acid in presence of ACTH is distinct from unchallenged wells and support the hypothesis of a direct adrenal action in patients with Cushing’s disease.

Morning Serum Cortisol as a Predictor for the HPA Axis Recovery in Cushing's Disease

BACKGROUND

The suppressed hypothalamic-pituitary-adrenal (HPA) axis after successful surgery for Cushing's disease (CD) will recover in almost all patients. We aimed to identify the predictive factors for HPA axis recovery in CD patients with postoperative remission. Design and Methods. This observational retrospective cross-sectional study enrolled 69 CD patients with postoperative remission in Huashan Hospital from 2015 to 2019. All subjects had a detailed clinical evaluation. The low-dose ACTH stimulation test (LDT) was conducted as the gold standard for assessing the HPA axis function.

RESULTS

Peak cortisol in LDT was found only to be positively correlative with morning serum cortisol (MSC) (ρ=0.451, p < 0.001). The MSC was higher (p < 0.001), and the median postoperative course was significantly longer (p=0.025) in the patients with the recovered HPA axis function compared with unrecovered patients. The AUC value of MSC for predicting the recovery of the HPA axis was 0.701, and the optimal cutoff was 6.25 μg/dl (sensitivity 85.19% and specificity 47.62%). Other useful cutoff values were 10.74 μg/dl (specificity 100%) and 4.18 μg/dl (sensitivity 100%). Besides, combined with the postoperative course, the AUC values were higher than MSC alone (0.935 vs. 0.701, p < 0.001).

CONCLUSIONS

MSC is a viable first-step diagnostic predictor for HPA axis recovery in CD patients with postoperative remission. For the patients with cortisol levels between 4.18 and 10.74 μg/dl, a confirmatory test should be conducted. When the MSC level was 10.74 μg/dl or greater, the replacement therapy could be discontinued.

Dynamics of postoperative serum cortisol after transsphenoidal surgery for Cushing's disease: implications for immediate reoperation and remission

OBJECTIVESuccessful transsphenoidal surgery for adrenocorticotropin hormone (ACTH)-producing pituitary tumors is associated with subnormal postoperative serum cortisol levels, which may guide decisions regarding immediate reoperation. However, little is known about the detailed temporal course of changes in serum cortisol in the immediate postoperative period, and the relationship of postoperative cortisol dynamics to remission and late recurrence.METHODSA single-center retrospective cohort analysis was performed for all patients undergoing pituitary surgery from 2007 through 2015. Standardized diagnostic and treatment algorithms were applied to all patients with potential Cushing's disease (CD), including microsurgical transsphenoidal adenomectomy (TSA) by a single surgeon. All patients had serum cortisol levels drawn at 6-hour intervals for 72 hours after surgery, and were offered reoperation within 3 days for normal or supranormal postoperative cortisol levels. Primary outcomes were 6-month remission and late recurrence; secondary outcomes were persistent postoperative hypocortisolism and surgical morbidity. Discriminatory levels of postoperative serum cortisol for predicting remission were calculated at various intervals after surgery using receiver operating characteristic (ROC) curves.RESULTSAmong 89 patients diagnosed with CD, 81 underwent initial TSA for a potentially curable lesion; 23 patients (25.8%) underwent an immediate second TSA. For the entire cohort, 6-month remission was achieved in 77.8% and late recurrences occurred in 9.5%, at a mean of 43.5 months. Compared with patients with a single surgery, those with an immediate second TSA had similar rates of remission (78.3% vs 77.6%) and late recurrence (5.6% vs 11.1%). The rate of hypocortisolism for patients with 2 surgeries (12/23, 52.2%) was significantly greater than that for patients with single surgeries (13/58, 22.4%; p < 0.001). There was no difference in the incidence of CSF leaks between the first and second operations. Remission was achieved in 58 (92.1%) of 64 patients who completed the 2-surgery protocol. The temporal course of postoperative serum cortisol levels among patients varied considerably, with subnormal nadir levels < 2 μg/dl occurring between 12 hours and 66 hours. Patients achieving remission had significantly lower mean serum cortisol levels at every time point after surgery (p < 0.01). By ROC curve analysis, nadir cortisol levels < 2.1 μg/dl were predictive of 6-month remission for the entire cohort over 3 days (positive predictive value [PPV] = 94%); discriminating cortisol levels for predicting remission on postoperative day (POD) 2 were < 5.4 μg/dl (PPV = 97%), although patients with remission after postoperative cortisol levels of 2-5 μg/dl had a significantly higher rate of late recurrence.CONCLUSIONSThere is substantial variation in the temporal course of serum cortisol levels over the first 72 hours after TSA for CD, with nadir levels predictive for remission occurring as late as POD 3. Although a cortisol level of 2.1 μg/dl at any point was an accurate predictor of 6-month remission, levels less than 5.4 μg/dl on POD 2 were reasonably accurate. These data may enable decisions regarding the efficacy of an immediate second surgical procedure performed during the same hospitalization; immediate reoperation is associated with excellent remission rates and low recurrence rates in patients otherwise unlikely to achieve remission, but carries a higher risk of permanent hypocortisolism.

Remission rate after transsphenoidal surgery in patients with pathologically confirmed Cushing's disease, the role of cortisol, ACTH assessment and immediate reoperation: a large single center experience

Postoperative serum cortisol is used as an indicator of Cushing's disease (CD) remission following transsphenoidal surgery (TSS) and guides (controversially) the need for immediate adjuvant treatment for CD. We investigated postoperative cortisol and adrenocorticotropic hormone (ACTH) levels as predictors of remission/recurrence in CD in a large retrospective cohort of patients with pathologically confirmed CD, over 6 years at a single institution. Midnight and morning cortisol, and ACTH at 24-48 h postoperatively (>24 h after last hydrocortisone dose) were measured. Remission was defined as normal 24-h urine free cortisol, normal midnight salivary cortisol, a normal dexamethasone-corticotropin releasing hormone (CRH) test or continued need for hydrocortisone, assessed periodically. Statistical analysis was performed using PASW 18. Follow up data was available for 52 patients (38 females and 14 males), median follow up was 16.5 month (range 2-143 months), median age was 45 years (range 21-72 years), 28 tumors were microadenomas and 16 were macroadenomas, and in eight cases no tumor was observed on magnetic resonance imaging. No patient with postoperative cortisol levels >10 mcg/dl were found to be in remission. Ten of the 52 patients with cortisol >10 mcg/dl by postoperative day 1-2 underwent a second TSS within 7 days. Forty-three patients (82.7%) achieved CD remission (36 after one TSS and 7 after a second early TSS) and six patients suffered disease recurrence (mean 39.2 ± 52.4 months). An immediate second TSS induced additional hormonal deficiencies (diabetes insipidus) in three patients with no surgical complications. Persistent disease was noted in nine patients despite three patients having an immediate second TSS. Positive predictive value for remission of cortisol <2 mcg/dl and ACTH <5 pg/ml was 100%. Cortisol and ACTH levels (at all postoperative time points and at 2 months) were correlated (r = 0.37, P < 0.001). Nadir serum cortisol of ≤2 mcg/dl and ACTH <5 pg/ml predicted remission (P < 0.005), but no level predicted lack of recurrence. Immediate postoperative ACTH/cortisol did not predict length of remission. No patients with postoperative cortisol >10 mcg/dl were observed to have delayed remission; all required additional treatment. There was no significant difference in age, body mass index, tumor size and length of follow-up between postoperative cortisol groups: cortisol ≤2 mcg/dl, cortisol >5 mcg/dl and cortisol >10 mcg/dl. Immediate postoperative cortisol levels should routinely be obtained in CD patients post TSS, until better tools to identify early remission are available. Immediate repeat TSS could be beneficial in patients with cortisol >10 mcg/dl and positive CD pathology: our combined (micro- and macroadenomas) remission rate with this approach was 82.7%. ACTH measurements correlate well with cortisol. However, because no single cortisol or ACTH cutoff value excludes all recurrences, patients require long-term clinical and biochemical follow-up. Further research is needed in this area.

Feasibility of endoscopic endonasal approach for recurrent pituitary adenomas after microscopic trans-sphenoidal approach

OBJECTIVE

The surgical approach for recurrent pituitary adenoma after trans-sphenoidal approach (TSA) is challenging. We report the outcomes of the endoscopic TSA for recurrent pituitary adenoma after microscopic TSA.

METHODS

From February 2010 to February 2013, endoscopic TSA was performed for removal of 30 recurrent pituitary adenomas after microscopic TSA. Twenty-seven (90%) patients had a clinically non-functioning pituitary adenoma. Twenty-four (80%) patients suffered from a visual disturbance related to tumor growth. The clinical features and surgical outcomes were retrospectively analyzed for the ophthalmological, endocrinological, and oncological aspects.

RESULTS

The mean tumor volume was 11.7 cm(3), and gross total resection was achieved in 50% of patients. The volumetric analysis based on the postoperative MR showed that the mean extent of resection rates were 90%. Vision was improved in 19 (79%) of 24 patients with visual symptoms, and endocrinological cure was achieved in all of three functioning pituitary adenomas; however, the post-operative follow-up endocrinological examination revealed a new endocrinological deficit in one patient. Two patients required antibiotics management for post-operative meningitis.

CONCLUSION

The endoscopic TSA can be an effective treatment option for recurrent pituitary adenoma after microscopic TSA with acceptable outcome.

Cushing's disease in 2012

The aim of this study was to review the literature published and the most important papers presented to meetings on Cushing's disease from October 2011 to September 2012. The selection has been performed according to the authors' criteria. Articles have been classified into five groups: quality of life and perception of the disease, clinical features and pathophysiology, comorbidity conditions, diagnosis, and treatment. The results and conclusions of each publication are discussed.

ACTH-independent macronodular adrenocortical hyperplasia reveals prevalent aberrant in vivo and in vitro responses to hormonal stimuli and coupling of arginine-vasopressin type 1a receptor to 11β-hydroxylase

Background

Adrenal Cushing’s syndrome caused by ACTH-independent macronodular adrenocortical hyperplasia (AIMAH) can be accompanied by aberrant responses to hormonal stimuli. We investigated the prevalence of adrenocortical reactions to these stimuli in a large cohort of AIMAH patients, both in vivo and in vitro.

Methods

In vivo cortisol responses to hormonal stimuli were studied in 35 patients with ACTH-independent bilateral adrenal enlargement and (sub-)clinical hypercortisolism. In vitro, the effects of these stimuli on cortisol secretion and steroidogenic enzyme mRNA expression were evaluated in cultured AIMAH and other adrenocortical cells. Arginine-vasopressin (AVP) receptor mRNA levels were determined in the adrenal tissues.

Results

Positive serum cortisol responses to stimuli were detected in 27/35 AIMAH patients tested, with multiple responses within individual patients occurring for up to four stimuli. AVP and metoclopramide were the most prevalent hormonal stimuli triggering positive responses in vivo. Catecholamines induced short-term cortisol production more often in AIMAH cultures compared to other adrenal cells. Short- and long-term incubation with AVP increased cortisol secretion in cultures of AIMAH cells. AVP also increased steroidogenic enzyme mRNA expression, among which an aberrant induction of CYP11B1. AVP type 1a receptor was the only AVPR expressed and levels were high in the AIMAH tissues. AVPR1A expression was related to the AVP-induced stimulation of CYP11B1.

Conclusions

Multiple hormonal signals can simultaneously induce hypercortisolism in AIMAH. AVP is the most prevalent eutopic signal and expression of its type 1a receptor was aberrantly linked to CYP11B1 expression.

Mifepristone effects on tumor somatostatin receptor expression in two patients with Cushing's syndrome due to ectopic adrenocorticotropin secretion

CONTEXT

Two patients presented with Cushing's syndrome due to ectopic ACTH secretion. Initial localization studies included computed tomography, magnetic resonance imaging, and octreoscans ((111)In-pentreotide scintigraphy), which were negative in both patients. They were treated with the glucocorticoid receptor antagonist mifepristone, with improvement in their clinical symptoms. Follow-up octreoscans after, respectively, 6 and 12 months showed the unequivocal presence of a bronchial carcinoid in both patients.

OBJECTIVE

The objective of the study was to correlate in vivo and in vitro findings in patients with ectopic ACTH-producing syndrome.

METHODS

We determined the expression of somatostatin and dopamine receptors by immunohistochemistry (patients 1 and 2), quantitative PCR, and in vitro culturing of tumor cells (patient 1 only). IN VITRO RESULTS: Both tumors were strongly positive for somatostatin receptor type 2 (sst(2)) on immunohistochemistry, whereas one of the tumors (patient 1) was also dopamine receptor subtype 2 (D(2)) positive on both immunohistochemistry and quantitative PCR. Octreotide (a sst(2) preferring analog) and cabergoline (D(2) agonist) both decreased the ACTH levels in the cultured tumor cells of patient 1.

CONCLUSION

We describe two patients with ACTH-producing bronchial carcinoids, in whom a direct down-regulatory effect of glucocorticoid levels on tumoral sst(2) receptor expression is suggested by a remarkable change in octreoscan status after successful mifepristone therapy. Further studies will have to demonstrate whether glucocorticoid lowering or antagonizing therapy may be used to improve the diagnostic accuracy of somatostatin receptor scintigraphy in patients with ectopic ACTH production of unknown primary origin.