Clinical Impact of New Reference Intervals for the Roche Prolactin II Immunoassay.

Context: The Roche prolactin immunoassay is used throughout the world. It reports higher values than the Siemens immunoassay but the manufacturer-defined reference intervals are similar. Patient results are often above the Roche upper limit but within the Siemens interval, causing diagnostic confusion. Objective: Establish new reference intervals for the Roche and Siemens prolactin immunoassays. Methods: We established new reference intervals for the Roche and Siemens immunoassays using 374 specimens from healthy outpatients. We performed chart review for unnecessary testing and treatment for 298 patients in a 6-month period with at least 1 Roche prolactin value above the manufacturer-defined upper limit and below our new upper limit. Results: The new upper limit for the Roche assay was 37.8 ng/mL (females) and 22.8 ng/mL (males). The manufacturer-defined limits were 23.3 ng/mL and 15.2 ng/mL, respectively. New intervals for the Siemens assay matched the manufacturer. No cases of clinically significant pathophysiologic prolactin excess were identified in patients with values between the manufacturer-defined upper reference limit and our new Roche upper limit. Unnecessary further evaluation in these patients included 459 repeat prolactin measurements, 57 macroprolactin measurements, 39 magnetic resonance imaging studies, and 28 endocrine referrals. Eleven patients received dopamine agonists. The minimum cost of excess care using Medicare reimbursement rates was $34 134, with substantially higher amounts billed to patients and their insurance providers. Conclusion: Adoption of new upper reference limits for the Roche prolactin assay of 37.8 ng/mL (females) and 22.8 ng/mL (males) would not delay diagnosis or necessary intervention in patients with clinically significant pituitary tumors but would reduce unnecessary evaluation in patients without pathophysiologic prolactin excess.

Alcohol-induced Cushing syndrome: report of eight cases and review of the literature.

Introduction: Alcohol-induced hypercortisolism (AIH) is underrecognized and may masquerade as neoplastic hypercortisolism [Cushing syndrome (CS)] obscuring its diagnosis. Objective and methods: In order to characterize AIH, we performed a chart review of eight patients (4 males and 4 females; 2014-2022) referred for evaluation and treatment of neoplastic hypercortisolism - six for inferior petrosal sinus sampling, one due to persistent CS after unilateral adrenalectomy, and one for pituitary surgery for Cushing disease (CD). Five underwent dDAVP stimulation testing. Results: All eight patients had clinical features of hypercortisolism and plasma ACTH levels within or above the reference interval confirming hypothalamic-pituitary mediation. All had abnormal low-dose dexamethasone suppression test and increased late-night salivary cortisol. Only one had increased urine cortisol excretion. In contrast to CD, the 5 patients tested had blunted or absent ACTH and cortisol responses to desmopressin. Two had adrenal nodules and one had abnormal pituitary imaging. Most patients underreported their alcohol consumption and one denied alcohol use. Elevated blood phosphatidyl ethanol (PEth) was required in one patient to confirm excessive alcohol use. All patients had elevations of liver function tests (LFTs) with AST>ALT. Conclusion: AIH is an under-appreciated, reversible cause of non-neoplastic hypercortisolism that is indistinguishable from neoplastic CS. Incidental pituitary and adrenal imaging abnormalities as well as under-reporting of alcohol consumption further confound the diagnosis. Measurement of PEth helps to confirm an alcohol use disorder. Elevations of LFTs (AST>ALT) and subnormal ACTH and cortisol responses to dDAVP help to distinguish AIH from neoplastic hypercortisolism.

New Cutoffs for the Biochemical Diagnosis of Adrenal Insufficiency after ACTH Stimulation using Specific Cortisol Assays.

CONTEXT: The normal cortisol response 30 or 60 minutes after cosyntropin (ACTH[1-24]) is considered to be ≥18 µg/dL (500 nmol/L). This threshold is based on older serum cortisol assays. Specific monoclonal antibody immunoassays or LC-MS/MS may have lower thresholds for a normal response. OBJECTIVE: To calculate serum cortisol cutoff values for adrenocorticotropic hormone (ACTH) stimulation testing with newer specific cortisol assays. METHODS: Retrospective analysis of ACTH stimulation tests performed in ambulatory and hospitalized patients suspected of adrenal insufficiency (AI). Serum samples were assayed for cortisol in parallel using Elecsys I and Elecsys II immunoassays, and when volume was available, by Access immunoassay and LC-MS/MS. RESULTS: A total of 110 patients were evaluated. Using 18 µg/dL as the cortisol cutoff after ACTH stimulation, 14.5%, 29%, 22.4%, and 32% of patients had a biochemical diagnosis of AI using the Elecsys I, Elecsys II, Access, and LC-MS/MS assays, respectively. Deming regressions of serum cortisol were used to calculate new cortisol cutoffs based on the Elecsys I cutoff of 18 µg/dL. For 30-minute values, new cutoffs were 14.6 µg/dL for Elecsys II, 14.8 µg/dL for Access, and 14.5 µg/dL for LC-MS/MS. Baseline cortisol <2 µg/dL was predictive of subnormal stimulated cortisol values. CONCLUSION: To reduce false positive ACTH stimulation testing, we recommend a new serum cortisol cutoff of 14 to 15 µg/dL depending on the assay used (instead of the historical value of 18 µg/dL with older polyclonal antibody assays). Clinicians should be aware of the new cutoffs for the assays available to them when evaluating patients for AI.

Continuous Etomidate Infusion for the Management of Severe Cushing Syndrome: Validation of a Standard Protocol.

OBJECTIVE: Demonstrate the safety and efficacy of a standardized intravenous etomidate infusion protocol in normalizing cortisol levels in patients with severe and life-threatening hypercortisolism. METHODS: A retrospective case series of seven patients representing nine episodes of severe hypercortisolism at two large academic medical centers was conducted. Patients were included in this series if they received an etomidate infusion for the treatment of severe and life-threatening hypercortisolism. The etomidate infusion was administered via a newly developed protocol designed to safely reduce cortisol levels until more long-term medical or definitive surgical therapy could be instituted. RESULTS: Seven patients representing nine episodes received etomidate treatment. In eight of nine episodes of therapy, rapid control of hypercortisolemia was achieved, generally defined as a serum cortisol level of 10 to 20 µg/dL. Patients with a median baseline cortisol of 105 µg/dL (range, 32 to 245 µg/dL) achieved a median nadir serum cortisol of 15.8 µg/dL (range, 6.9 to 27 µg/dL) after a median of 38 hours (range, 26 to 134 hours). CONCLUSIONS: A standardized continuous intravenous etomidate infusion protocol is a safe and effective means of achieving a serum cortisol level of 10 to 20 µg/dL in patients with severe hypercortisolemia.

POSTSURGICAL RECURRENT CUSHING DISEASE: CLINICAL BENEFIT OF EARLY INTERVENTION IN PATIENTS WITH NORMAL URINARY FREE CORTISOL.

OBJECTIVE: To assess the performance of biochemical markers in the detection of recurrent Cushing disease (CD), as well as the potential benefit of early intervention in recurrent CD patients with elevated late-night salivary cortisol (LNSC) and normal urinary free cortisol (UFC). METHODS: The design was a single-center, retrospective chart review. Patients treated by the authors from 2008-2013 were included. Recurrence was defined by postsurgical remission of CD with subsequent abnormal LNSC, UFC, or dexamethasone suppression test (DST). RESULTS: We identified 15 patients with postsurgical recurrent CD after initial remission; all but one underwent testing with LNSC, DST, and UFC. Although 12 of 15 patients had normal UFC at time of recurrence, DST was abnormal in 11 of 15, and all 14 patients with LNSC results had ≥1 elevated measurement. Nine patients (7 with normal UFC) showed radiologic evidence of a pituitary tumor at time of recurrence. Among the 14 patients with available follow-up data, 12 have demonstrated significant improvement since receiving treatment. Five patients underwent repeat pituitary surgery and 4 achieved clinical and biochemical remission. Eight patients received mifepristone or cabergoline, and 6 showed clinical and/or biochemical improvement. Three patients (2 with prior mifepristone) underwent bilateral adrenalectomy and 2 demonstrated significant clinical improvements. CONCLUSION: LNSC is more sensitive than UFC or DST for detection of CD recurrence. Prompt intervention when LNSC is elevated, despite normal UFC, may yield significant clinical benefit for many patients with CD. Early treatment for patients with recurrent CD should be prospectively evaluated, utilizing LNSC elevation as an early biochemical marker. ABBREVIATIONS: ACTH = adrenocorticotropic hormone CD = Cushing disease CS = Cushing syndrome CV = coefficient of variation DST = dexamethasone suppression test IPSS = inferior petrosal sinus sampling LNSC = late-night salivary cortisol QoL = quality of life TSS = transsphenoidal adenoma resection UFC = urinary free cortisol.

Association between body mass index and multigland primary hyperparathyroidism.

INTRODUCTION: Multigland disease (MGD) accounts for 15% of sporadic primary hyperparathyroidism (pHPT). Several studies have reported a link between obesity and calcium metabolism (e.g., increased incidence of pHPT, higher levels of parathyroid hormone, lower vitamin D levels, and larger parathyroid glands). Obese patients have also been shown to require reoperation for persistent/recurrent pHPT more often than nonobese controls. We hypothesize that obese patients may have a higher prevalence of MGD. METHODS: This was a retrospective review of a prospectively collected parathyroid database that included adult patients with sporadic pHPT, who underwent initial parathyroidectomy between 1999 and 2013. Demographic, clinicopathologic, operative, and laboratory data were assessed for associations with MGD. RESULTS: Of 1305 consecutive patients, 200 (15%) had MGD. Median age was 59 y. Univariate analyses demonstrated that MGD was associated with age > 60 y, higher body mass index (BMI), history of lithium therapy, lower 24-h urine calcium excretion, higher serum alkaline phosphatase levels, and smaller size of the first excised parathyroid gland. On multivariate analyses, predictors of MGD were BMI 30-39.9 kg/m(2) (odds ratio [OR] 1.5; 95% confidence interval [CI] 1.2-2.5), BMI ≥ 40 kg/m(2) (OR 1.8; 95% CI 1.3-3.1), and smaller size of the first excised parathyroid (OR 0.7; 95% CI 0.6-0.8). CONCLUSIONS: This study demonstrates a higher incidence of MGD in obese and morbidly obese patients. Due to a higher risk of MGD, surgeons should have a lower threshold to perform bilateral exploration in obese patients, especially if the first excised parathyroid gland is relatively small.

Cosyntropin stimulation testing on postoperative day 1 allows for selective glucocorticoid replacement therapy after adrenalectomy for hypercortisolism: Results of a novel, multidisciplinary institutional protocol.

BACKGROUND: Secondary adrenal insufficiency (AI) can occur after unilateral adrenalectomy for adrenal-dependent hypercortisolism. Postoperative glucocorticoid replacement (GR), although given routinely, may not be necessary. We sought to identify factors that, in combination with postoperative day 1 cosyntropin stimulation testing (POD1-CST), would predict the need for GR. METHODS: We reviewed 31 consecutive patients who underwent unilateral adrenalectomy for hypercortisolism (study patients) or hyperaldosteronism (control patients). A standard POD1-CST protocol was used. Hydrocortisone was started for clinical evidence of AI, basal plasma cortisol ≤ 5 (µg/dL), or a stimulated plasma cortisol <18. RESULTS: A normal POD1-CST was found in all nine control patients and 11 of 22 patients (50%) with Cushing's syndrome; the other 11 study patients (50%) received GR based on the POD1-CST. These patients were younger (51 vs 62 years; P = .017), had a higher body mass index (BMI; 31 vs 29 kg/m(2)), and smaller adrenal neoplasms (16.9 vs 33.0 g; P = .009) than non-GR study patients. CONCLUSION: After unilateral adrenalectomy for hypercortisolism, only 50% of patients received GR. No preoperative biochemical characteristics were associated with postoperative AI, although patients who received GR were younger, and tended to have a higher BMI and smaller adrenal nodules. Use of this novel protocol for postoperative dynamic adrenal function testing prevented unnecessary GR in 50% of patients and allowed for individualized patient care.

Discovery of Cushing's Syndrome After Bariatric Surgery: Multicenter Series of 16 Patients.

PURPOSE: The aim of this study is to demonstrate the importance of considering Cushing's syndrome (CS) as a potential etiology for weight gain and metabolic complications in patients undergoing bariatric surgery (BS). DESIGN AND METHODS: This is a retrospective chart review case series of patients (n = 16) with CS from five tertiary care centers in the USA who had BS. RESULTS: Median age at BS surgery was 35.5 years (median 2.5 years between BS and CS surgery). CS was not identified in 12 patients prior to BS. Four patients had CS surgery prior to BS, without recognition of recurrent or persistent CS until after BS. Median body mass index (BMI) values before BS, nadir after BS, prior to surgery for CS, and after surgery for CS were 47, 31, 38, and 35 kg/m(2), respectively. Prior to BS, 55 % of patients had hypertension and 55 % had diabetes mellitus. Only 17 % had resolution of hypertension or diabetes mellitus after BS. CONCLUSION: CS may be under-recognized in patients undergoing BS. Testing for CS should be performed prior to BS in patients with features of CS and in post-operative BS patients with persistent hypertension, diabetes mellitus, or excessive weight regain. Studies should be conducted to determine the role of prospective testing for CS in subjects considering BS.