Evaluation of four automated clinical analyzers for the determination of total 25(OH)D in comparison to a certified LC-MS/MS.

OBJECTIVES: The aim of this study was to compare the results of five methods for the determination of total 25(OH)D. For that purpose, two mass spectrometry and three immunoassay methods were used. METHODS: A total of 124 serum samples were analyzed on five different methods (i.e., a reference LC-MS/MS, Cascadion, Lumipulse, Roche Elecsys II and Roche Elecsys III). Analytical performance against LC-MS/MS was evaluated and compared to the Milan models 1 (analytical performance based on the clinical outcome using thresholds of 12, 20 and 30 ng/mL) and 2 (analytical performance based on biological variation). Additionally, imprecision studies and accuracy using NIST SRM972a samples were carried out. RESULTS: Compared to the reference LC-MS/MS method, the Lumipulse and the Roche Elecsys III assays reached the optimal criterion for bias, while the Cascadion met the desirable one. The Roche Elecsys II was not able to reach the minimal criteria. The proportion of correctly classified patients was higher using the Cascadion (95.2%) compared to the three immunoassays. In addition to its better precision, the Cascadion was not impacted by a high concentration of 3-epi-25(OH)D3 compared to the three immunoassays. CONCLUSIONS: Compared to the LC-MS/MS reference method, the Cascadion presented the highest level of concordance at medical decision cut-offs for total 25(OH)D and reached the desirable specification for bias. Moreover, the presence of 3-epi-25(OH)D3 in enriched samples was only problematic in immunoassay methods, and especially considering Roche Elecsys methods. The release of performant fully automated mass spectrometry assays with high throughput might therefore facilitate the wide scale adoption of LC-MS/MS, even in non-specialized clinical laboratories.

Assessment of the Androstenedione Assay on a Roche Analytical Platform and Comparison with Different Methods.

BACKGROUND: D4-androstenedione (D4ASD) is an intermediate hormone of androgen biosynthesis by the gonads and the adrenal glands. The interest in D4ASD concentration assessment resides in diagnostics of androgenic hyperproduction pathologies. Currently, many D4ASD quantification methods are available on the market including immunological methods that remain problematic due to the possible cross-reactivity with endogenous or exogenous steroids. METHODS: Recently Roche® launched a new fully automated instrument for the measurement of D4ASD concentration. In this paper, the criteria of analytical performance (repeatability and intermediate precision) of the D4ASD Roche® assay were assessed and compared with 2 different methods including a radioimmunoassay (RIA) as well as a liquid chromatography tandem mass spectrometry (LC-MS/MS) method. RESULTS: Repeatability and intermediate precision of the D4ASD Roche® were acceptable according to the prede-fined RICOS standard (CV ≤ 7.9%) and the assay showed a good correlation with other assays considering the 95% CI obtained for the slope and the y-intercept. CONCLUSIONS: This method demonstrates acceptable criteria of analytical performance with an intermediate imprecision and a trueness within the fixed acceptance limits.

The free cortisol calculated: correlation with the free cortisol concentrations measured with liquid chromatography-tandem mass spectrometry after equilibrium dialysis and establishment of reference intervals.

BACKGROUND: Changes in cortisol binding globulin (CBG) impact the total serum cortisol concentration and affect the accurate assessment of adrenal function. Free biologically cortisol can be calculated using different equations or directly measured after complicated procedures. METHODS: The free cortisol index (FCI) obtained using the Bonte formula as well as the free cortisol concentration calculated (Coolens equation) were first estimated for 45 healthy workers. The CBG level was determined by a competitive radioimmunoassay and the total cortisol concentration, was measured with an electrochemiluminescent assay. The correlations between FCI, the free cortisol concentrations calculated and the free cortisol levels measured with liquid chromatography-tandem mass spectrometry after equilibrium dialysis were studied for those 45 samples. Reference limits were established on 158 healthy hospital workers and patients with serum samples collected between 7:30 am and 10 am. RESULTS: The FCI as well as the free cortisol concentrations calculated obtained for the 45 samples correlated significantly with the free cortisol levels measured. Although the cortisol and CBG levels were statistically higher in women using contraceptives compared with women not taking them as well as men, the calculated FCI and free cortisol concentrations did not differ between these groups. The medians (P2.5-P97.5) obtained for the 158 healthy workers were respectively 26.4% (12.3-51.6%) and 10.6 nmol/L (4.3-26.7 nmol/L). CONCLUSIONS: This study highlighted a significant correlation between the FCI, the free cortisol concentrations calculated and the free cortisol levels measured with LC-MS/MS, it has also allowed the establishment of reference intervals for calculated FCI and free cortisol.

Two-site evaluation of the Roche Elecsys Vitamin D total III assay.

OBJECTIVES: The high request for vitamin D testing in the last decades has led manufacturers to develop assays on automated immunoassay platforms. The objective of this study was to evaluate the performance of the new Elecsys Vitamin D total III assay for the measurement of total 25(OH)D. METHODS: A total of 844 serum samples collected in two clinical laboratories were used to evaluate the new Roche Elecsys Vitamin D total III assay. Comparisons with Roche Elecsys Vitamin D total II and liquid chromatography tandem mass spectrometry (LC-MS/MS) were carried out. Additionally, assay imprecision, linearity, matrix effects, biotin interference, cross-reactivity with 24,25(OH)2D3 and 3-epi-25(OH)D3, and outlier rate were evaluated for the Elecsys Vitamin D total III assay. RESULTS: Only the comparison between LC-MS/MS and Roche Elecsys Vitamin D total III achieved the optimal specification for bias (i.e., <3.4%). Imprecision, linearity and matrix effects showed acceptable results. The biotin interference threshold was increased up to 1,200 ng/mL and the outlier rate was low (0.26%). The cross-reactivity with 24,25(OH)2D3 and 3-epi-25(OH)D3 was weak or modest in available patient samples. However, using SRM972a with a high level of 3-epi-25(OH)D3 (enriched) revealed an important cross-reactivity with both Roche Elecsys Vitamin D total II and III assays (+74.7% and +73.7%). CONCLUSIONS: In conclusion, the Roche Elecsys Vitamin D total III assay presents several advantages compared to the previous assay generation: higher biotin interference threshold, broader measuring range, and better comparability with LC-MS/MS. However, the cross-reactivity toward 3-epi-25(OH)D3 is still problematic in high titer samples.

Development and validation of a simple correction method for the measurement of neuron-specific enolase in hemolyzed serum samples.

The Neuron-specific enolase (NSE), a biomarker of neuroendocrine tumors or ischemic brain damage, has limited clinical applicability since its measurement is overestimated by hemolysis. In this study, an NSE correction method was developed for hemolyzed samples. The NSE concentration and the hemolysis index (HI) of serum were measured before and after spiking a hemolysate prepared with red blood cells from the serum-separating tube and extrapolating the NSE value corresponding to a HI of zero. To validate the approach (n = 46), NSE concentrations and HI were measured before (NSE0 and HI0) and after spiking the samples with 50 µL (HIA, NSEA) and 100 µL (HIB, NSEB) of hemolysate. A linear regression analysis was performed between (HIA, NSEA) and (HIB, NSEB). The y-intercept was taken as the corrected NSE concentration (NSEintercept) and compared with NSE0. On the same samples, the equation of Tolan et al. was applied and the corrected values of NSE (NSEcorr) were compared to NSE0. The average bias (±SD) between the NSE0 and the NSEintercept was equal to -3.2% (± 14.3) versus 34.6% (± 19.8) against the NSEcorr. Applying the allowable total error proposed by the European Federation of Laboratory Medicine, 72% of the NSE results were adequately corrected while the reference method corrected only 8.7% of the results. The individualized hemolysis correction method developed is simple, fast, requires one serum-separating tube, provides increased accuracy compared to the method described by Tolan et al. and should improve the quality of patient care.

Biomarkers for Early Diagnosis of Hemophagocytic Lymphohistiocytosis in Critically Ill Patients.

Many biomarkers have been proposed for the diagnosis of secondary hemophagocytic lymphohistiocytosis (HLH) in adults, but comparative studies are lacking. We analyzed ferritin, glycosylated ferritin, soluble CD25, CD163 and CD14, IL-6, IFN-γ, IL-18, IL-10, IL-1ß, IL-12p70, IL-17α, IP-10, and CXCL9 levels to differentiate HLH from sepsis in critically ill patients. Of 120 patients, HLH was confirmed for 14 patients. Among the biomarkers tested, ferritin, IL-18, and glycosylated ferritin were the most efficient parameters for early diagnosis of HLH. With a sensitivity set at 85%, ferritin, IL-18, and glycosylated ferritin were the biomarkers with the highest specificity: 84, 79, and 71% respectively. Combining IL-18 with the HScore provided a new score with an increased specificity compared to the HScore alone, 86% compared to 70% with a sensitivity set at 100%. A distinct cytokine pattern was highlighted in patients with malignancy-triggered HLH, with highly increased levels of INF-É£ and CXCL9, compared to HLH secondary to infection. This is the largest study available to date, comparing diagnostic biomarkers for HLH on a cohort of critically ill adult patients. Serum ferritin was the most discriminating parameter for early diagnosis of secondary HLH. IL18*HScore was identified as a highly potential score.

ß-Lactam Dosage Regimens in Septic Patients with Augmented Renal Clearance.

Augmented renal clearance is commonly observed in septic patients and may result in insufficient ß-lactam serum concentrations. The aims of this study were to evaluate potential correlations between drug concentrations or total body clearance of ß-lactam antibiotics and measured creatinine clearance and to quantify the need for drug dosage adjustments in septic patients with different levels of augmented renal clearance. We reviewed 256 antibiotic measurements (512 drug concentrations) from a cohort of 215 critically ill patients who had a measured creatinine clearance of ≥120 ml/min and who received therapeutic drug monitoring of meropenem, cefepime, ceftazidime, or piperacillin from October 2009 until December 2014 at Erasme Hospital. Population pharmacokinetic (PK) analysis of the data was performed using the Pmetrics software package for R. Fifty-five percent of drug concentrations showed insufficient ß-lactam serum concentrations to treat infections due to Pseudomonas aeruginosa There were significant, yet weak, correlations between measured creatinine clearance and trough concentrations of meropenem (r = -0.21, P = 0.01), trough concentrations of piperacillin (r = -0.28, P = 0.0071), concentrations at 50% of the dosage interval (r = -0.41, P < 0.0001), and total body clearance of piperacillin (r = 0.39, P = 0.0002). Measured creatinine clearance adequately explained changes in drug concentrations in population pharmacokinetic models for cefepime, ceftazidime, and meropenem but not for piperacillin. Therefore, specific PK modeling can predict certain ß-lactam concentrations based on renal function but not on absolute values of measured creatinine clearance, easily available for clinicians. Currently, routine therapeutic drug monitoring is required to adjust daily regimens in critically ill patients receiving standard dosing regimens.

Baseline hepcidin measurement in the differential diagnosis of anaemia for elderly patients and its correlation with the increment of transferrin saturation following an oral iron absorption test.

Background Anaemia is often multifactorial in the elderly, with a frequent association between iron deficiency anaemia (IDA) and anaemia of chronic disease (ACD). The primary objective of our study was to investigate whether baseline hepcidin measurement could be useful for identifying iron deficiency (ID) in anaemic elderly patients. The secondary objective was to assess whether baseline hepcidin concentrations correlated with the relative increase of transferrin saturation (TS) after an oral iron absorption test (OIAT). Methods Blood samples were collected between 7:30 am and 10:00 am in 328 geriatric outpatients, 102 underwent the OIAT. Types of anaemia were classified according biochemical and clinical criteria. TS and hepcidin were measured at baseline and 4 h after the iron dose. The ability of baseline hepcidin measurement to highlight ID in elderly anaemic patients was assessed using a receiver operator curve (ROC) analysis. Correlations between baseline hepcidin levels and the increment of TS following the OIAT were investigated using the Spearman coefficient. Results Among 328 included patients, 78 (23.8%) suffered from anaemia; 13 (4.0%), 19 (5.8%), 27 (8.2%) and 19 (5.8%) patients fulfilled criteria for IDA, IDA/ACD, ACD and unexplained anaemia, respectively. By multivariable analysis, creatinine, C-reactive protein, ferritin, Delta TS and Delta hepcidin were independently associated with baseline hepcidin concentrations. The area under the ROC curve (95% confidence interval) was 0.900 (0.830-0.970) for baseline hepcidin measurement. Baseline hepcidin levels correlated negatively with the relative increase in TS with a Spearman coefficient of -0.742. Conclusions Baseline hepcidin levels could be a useful tool to identify ID in anaemic elderly patients and may predict acute iron response following OIAT.

Comparison of two assays measuring human chorionic gonadotrophin serum concentrations in pregnancy termination and trophoblastic or non-trophoblastic tumours.

BACKGROUND: Differences in human chorionic gonadotrophin (hCG) results provided by the commercial immunoassays reflect the heterogeneity of antibodies and the use of suboptimal standards. As a consequence, the principal forms of hCG and metabolites are differentially detected and the hCG tests are not suited for the same clinical applications. Conflicting results are available in the literature regarding which hCG variants are recognized by the Roche Elecsys hCG + ß test. The aim of our study was to compare the hCG concentrations provided by the Siemens Immulite 2000 test and the Roche test as well as to assess the concordance between both assays. METHODS: In this purpose, 152 samples obtained from women and 44 samples from men were analysed by both tests during the follow-up of pregnancy termination, gestational trophoblastic disease and malignancies. The intermediate precision of the Roche test was also investigated on a pool with a low hCG concentration. RESULTS AND CONCLUSIONS: The hCG concentrations measured with the Roche test were slightly lower compared with the Siemens assay; mean biases of -34.2% and -8% were respectively obtained for hCG values ≤100 UI/L and higher than 100 UI/L. The overall agreement between both assays was 96.1% for women and 97.7% for men. By using an upper reference limit of 3.2 UI/L for women and 1.6 UI/L for men, the Roche test demonstrated a respective concordance of 98.7% and 100%. This test also yielded an excellent precision with a coefficient of variation of 2.8% at a mean hCG concentration of 7 UI/L.

Serum ß-lactam concentrations in critically ill patients with cirrhosis: a matched case-control study.

BACKGROUND & AIMS: The pharmacokinetics of ß-lactam antibiotics have not been well defined in critically ill patients with cirrhosis. METHODS: We reviewed data from critically ill patients with cirrhosis and matched controls in whom routine therapeutic drug monitoring of two broad-spectrum ß-lactam antibiotics (piperacillin/tazobactam and meropenem) had been performed. Serum drug concentrations were measured twice by high-performance liquid chromatography. Antibiotic pharmacokinetics were calculated using a one-compartment model. We considered that therapy was adequate when serum drug concentrations were between 4 and 8 times the minimal inhibitory concentration of Pseudomonas aeruginosa during optimal periods of time for each drug (≥ 50% for piperacillin/tazobactam; ≥ 40% for meropenem). RESULTS: We studied 38 patients with cirrhosis (16 for piperacillin/tazobactam and 22 for meropenem) and 38 matched controls. Drug dosing was similar in the two groups. The pharmacokinetics analysis showed a lower volume of distribution of meropenem (P = 0.05) and a lower antibiotic clearance of piperacillin/tazobactam (P = 0.009) in patients with cirrhosis than in the matched controls. Patients with cirrhosis were more likely than those without cirrhosis to have excessive serum ß-lactam concentrations (P = 0.015), in particular for piperacillin/tazobactam. CONCLUSIONS: Standard ß-lactam antibiotics regimens resulted in excessive serum concentrations in two thirds of the patients with cirrhosis. This was particularly true for piperacillin/tazobactam, probably because of reduced drug clearance.

Hepcidin on 24-hour urine collection: preanalytical aspects and correlation with ferritin levels.

BACKGROUND: Urine hepcidin measurement is a potential non-invasive tool for assessing iron stores. However, hepcidin, due to its amphipathic structure, tends to aggregate and to adhere to surfaces in a protein-poor environment. In this study, we assessed the effect of solid bovine serum albumin (BSA) at different final concentrations (0, 2.5 or 5 g/L) in limiting the loss of hepcidin in spot urine samples. We also explored how hepcidin measured on plasma, spot or 24-hour urine collections can identify iron deficiency. METHODS: Hepcidin levels were quantified on plasma, spot (with or without BSA) or 24-h urine collections for 33 volunteers. Hematological and iron status parameters were measured for each individual. The ability to detect iron deficiency (defined as a ferritin level <30 µg/L) based on plasma, spot or 24-h urine collections hepcidin levels was assessed by the means of receiver operator curves analysis. RESULTS: The addition of BSA into urine prior to sample collection prevented hepcidin loss by 13.3% (mean) in spot urine samples whatever the amount. The areas under the receiver operator curves obtained for detecting iron deficiency were respectively 0.94 and 0.93 for hepcidin levels obtained on plasma and 24-h urine collections. CONCLUSION: In this study, we showed that the addition of solid BSA into urine sample collection containers could prevent aggregation of hepcidin and that 24-h urine hepcidin levels could be as efficient as plasma concentrations for identifying iron deficiency.

Renal and prostate stones composition in alkaptonuria: a case report.

Alkaptonuria is a genetic disorder characterized by an accumulation of homogentisic acid due to an enzymatic defect of homogentisate 1,2 dioxygenase. The homogentisic acid is excreted exclusively by both glomerular filtration and tubular secretion leading to the renal parenchyma being exposed to high concentrations of homogentisic acid. The alkaptonuric patients are at higher risk of renal stones (and of prostate stones for males), usually in the later stages of the disease. We describe the case of a 51-year-old man whose renal and prostate stones were analyzed by X-ray diffraction and infrared spectroscopy, respectively. We review the cases of alkaptonuria (AKU) patients reported in the literature for whom the composition of kidney or prostate stones was assessed with physical or chemical techniques. In this paper, we also discuss the advantages and drawbacks of the different methodologies.

Case-control study of drug monitoring of ß-lactams in obese critically ill patients.

Severe sepsis and septic shock can alter the pharmacokinetics of broad-spectrum ß-lactams (meropenem, ceftazidime/cefepime, and piperacillin-tazobactam), resulting in inappropriate serum concentrations. Obesity may further modify the pharmacokinetics of these agents. We reviewed our data on critically ill obese patients (body mass index of ≥ 30 kg/m(2)) treated with a broad-spectrum ß-lactam in whom therapeutic drug monitoring was performed and compared the data to those obtained in critically nonobese patients (body mass index of <25 kg/m(2)) to assess whether there were differences in reaching optimal drug concentrations for the treatment of nosocomial infections. Sixty-eight serum levels were obtained from 49 obese patients. There was considerable variability in ß-lactam serum concentrations (coefficient of variation of 50% to 92% for the three drugs). Standard drug regimens of ß-lactams resulted in insufficient serum concentrations in 32% of the patients and overdosed concentrations in 25%. Continuous renal replacement therapy was identified by multivariable analysis as a risk factor for overdosage and a protective factor for insufficient ß-lactam serum concentrations. The serum drug levels from the obese cohort were well matched for age, gender, renal function, and sequential organ failure assessment (SOFA) score to 68 serum levels measured in 59 nonobese patients. The only difference observed between the two cohorts was in the subgroup of patients treated with meropenem and who were not receiving continuous renal replacement therapy: serum concentrations were lower in the obese cohort. No differences were observed in pharmacokinetic variables between the two groups. Routine therapeutic drug monitoring of ß-lactams should be continued in obese critically ill patients.

A new regimen for continuous infusion of vancomycin during continuous renal replacement therapy.

INTRODUCTION: Continuous infusion (CI) of high-dose vancomycin is often used to treat life-threatening infections caused by less-susceptible Gram-positive bacteria. However, this approach has not been well studied in patients on continuous renal replacement therapy (CRRT). The aim of this study was to evaluate the adequacy of a new CI vancomycin regimen in septic patients undergoing CRRT. METHODS: In this prospective study we measured vancomycin concentrations obtained with a new CI regimen for CRRT, which included a loading dose of 35 mg/kg given over a 4 h period followed by a daily dose of 14 mg/kg. Vancomycin concentrations were measured: at the end of the loading dose (T1); 12 h after the onset of therapy (T2); and 24 h after the onset of therapy (T3). Drug concentrations (at T2 and T3) were considered adequate if between 20 and 30 mg/L. CRRT intensity was calculated as: dialysate rate (mL/kg/h) + ultrafiltration rate (mL/kg/h). Vancomycin population pharmacokinetics were calculated using non-linear mixed-effects modelling. RESULTS: We studied 32 patients who received median (IQR) loading and daily vancomycin doses of 2750 mg (2250-3150) and 1100 mg (975-1270), respectively. Drug concentrations were: T1, 44 mg/L (38-58); T2, 27 mg/L (24-31); and T3, 23 mg/L (19-31). Vancomycin concentrations were adequate in 22/32 patients (69%) at T2 and in 20/32 (63%) at T3. The two relevant covariates that significantly affected drug concentrations were body weight and CRRT intensity. CONCLUSIONS: This new vancomycin regimen allowed the rapid achievement of target drug concentrations in the majority of patients. CRRT intensity had an influence on vancomycin clearance.

Ovarian stimulation does not induce thyrotropin receptor autoantibodies in women with thyroid autoimmunity.

Women of subfertile couples with thyroid autoimmunity (TAI) have an increased risk of miscarriage when pregnant after an assisted reproductive technology (ART) treatment. This might amongst others be due to the presence of thyrotropin receptor antibodies (TSH-R-Ab) that can impede the development of the corpus luteum. TSH-R-Ab can be present in women with TAI and/or be induced by the ovarian stimulation procedure (OS) that is performed to initiate the ART. In this prospective pilot study, we determined the presence of both binding and functional TSH-R-Ab (stimulating or blocking) with five different assays before and after OS in ten women (eleven cycles) with TAI of subfertile couples and in one woman without TAI. Mean (SD) age was 38.8 (±3.2) years, median (range) cumulative OS dose 1413 (613-2925) IU/L. Median baseline serum levels of thyrotropin, free thyroxine, and thyro-peroxidase antibodies were 2.33 (2.23-2.61) mIU/L, 16.8 (14.4-18.5) pmol/L and 152 (86-326) kIU/L, respectively. Oestradiol levels increased during OS from 40 (26-56) ng/L to 963 (383-5095) ng/L; P < .01. TSH-R-Ab measurements in all subject samples were below the cut-off of the corresponding immunoassay and four bioassays before or after OS.

Expert consensus statement on acute hepatic porphyria in Belgium.

Acute hepatic porphyrias (AHP) are a group of four different rare to ultra-rare, severely debilitating, and sometimes fatal diseases that significantly impact patients' lives: 5-aminolevulinic acid (ALA) dehydratase deficiency porphyria (ADP), acute intermittent porphyria (AIP), hereditary coproporphyria (HCP), and variegate porphyria (VP). Based on literature estimates, a conservative estimate of the number of AHP patients in Belgium requiring treatment, defined as patients experiencing recurrent attacks and/or chronic debilitating symptoms, is likely limited to 11-34 patients. These patients face a considerable unmet need, as there is currently no pharmaceutical treatment available that effectively prevents attacks and has an impact on other chronic symptoms of the disease.A panel consisting of the two European Porphyria Network1 (EPNet) centers in Belgium (Center for inborn errors of metabolism of UZ Leuven and the 'Centre Belge des Porphyries' of Erasme Hospital and LHUB-ULB) participated in an advisory board on 24 January 2020. Representatives of the sponsoring pharmaceutical company, Alnylam Pharmaceuticals, organized and attended the meeting. The objective of the meeting was to obtain expert input on the state-of-the-art clinical practice of AHP in Belgium. Following this meeting, this expert consensus statement was drafted, in collaboration with and coordinated by the EPNet centers in Belgium. This statement provides an overview of the state-of-the art in AHP, by means of a concise overview of AHP pathophysiology, clinical manifestations, and burden of disease, (Belgian) epidemiology, treatments, and proposed organization of care.

Two-day low-dose dexamethasone suppression test more accurate than overnight 1-mg in women taking oral contraceptives.

INTRODUCTION: Late-night salivary cortisol (LSaC) and 24-h urinary free cortisol measurement, and overnight 1-mg dexamethasone suppression test (1 mg-DST) are the first-line screening tests recommended for Cushing's syndrome. Through elevations in the level of cortisol-binding globulin, oral contraceptive agents lead to increases in the total plasma cortisol concentration, yielding false-positive 1 mg-DST results. OBJECTIVE: To compare the accuracy of the overnight 1-mg DST and two-day low-dose DST (2d-DST) in female volunteers taking combined oestrogen-progestin oral contraceptives (COCs). METHODS: This prospective study enrolled 30 healthy participants. Their plasma cortisol response levels were compared after the 1-mg DST and 2d-DST and classified into three categories: normal (≤50 nmol/L), doubtful (51-138 nmol/L) and abnormal (>138 nmol/L). Salivary cortisol was also measured at late night and after the DSTs. RESULTS: Following the 1-mg DST and 2d-DST, the plasma cortisol concentrations decreased to a median of 69 nmol/L and 37 nmol/L, respectively (p < 0.001). A statistically significant higher proportion of unclear or abnormal results were observed after the 1-mg DST (63%) than after the 2d-DST (27%) (p = 0.004). None of the values were >138 nmol/L after the 2d-DST, while 11% of them were abnormal after the 1-mg DST (p = 0.25). No LSaC value was abnormal. CONCLUSION: Our results suggest that, when late-night salivary cortisol is not available, the 2d-DST could be a better screening option than the 1-mg DST for women taking oral contraceptive agents who are reluctant to stop them. This finding requires confirmation in those with a suspicion of hypercortisolism.