Reference ranges of late-night salivary cortisol and cortisone measured by LC-MS/MS and accuracy for the diagnosis of Cushing's syndrome

Neoplastic hypercortisolism: Cut-off values for late-night salivary cortisol & cortisone

OBJECTIVES

One of the recommended initial tests for diagnosing neoplastic hypercortisolism is the measurement of late-night salivary cortisol (CortisolLNSa). Published cut-off values for CortisolLNSa and late-night salivary cortisone (CortisoneLNSa) vary widely between studies. This study aims to establish cut-off values for CortisolLNSa and CortisoneLNSa using liquid chromatography-tandem mass spectrometry and to determine which salivary hormone performs better in distinguishing between people with and without neoplastic hypercortisolism.

METHODS

A retrospective study was conducted on subjects screened for endogenous hypercortisolism at Amsterdam UMC between December 2015 and February 2022. 25 subjects with and 430 subjects without neoplastic hypercortisolism were included. The diagnosis neoplastic hypercortisolism was confirmed by histology and postoperative clinical features, not on biochemical tests, and excluded based on a follow-up of at least 12 months without progressive clinical signs of neoplastic hypercortisolism. Salivary samples were collected between 22:00-23:59 h and CortisolLNSa and CortisoneLNSa concentrations were measured using liquid chromatography-tandem mass spectrometry.

RESULTS

The median CortisolLNSa was 7.8 nmol/L for subjects with and 0.8 nmol/L for subjects without neoplastic hypercortisolism (p < 0.001). The median CortisoneLNSa was 35.5 nmol/L and 5.3 nmol/L, respectively (p < 0.001). Optimal diagnostic accuracy was established at 2.25 nmol/L for CortisolLNSa (sensitivity 92 %, specificity 89 %, positive predictive value 32.9 %, negative predictive value 99.5 %) and 15.5 nmol/L for CortisoneLNSa (sensitivity 93.8 %, specificity 94.5 %, positive predictive value 46.9 %, negative predictive value 99.7 %).

CONCLUSIONS

We established cut-off values for CortisolLNSa and CortisoneLNSa for the diagnosis of neoplastic hypercortisolism. CortisoneLNSa provided the highest diagnostic accuracy and we therefore recommend it as the preferred salivary measurement.

Who and how to screen for endogenous hypercortisolism in adrenal and pituitary incidentaloma

PURPOSE

Adrenal incidentalomas (AIs) and pituitary incidentalomas (PIs) have become frequent findings in the last two decades due to the widespread use of cross-sectional imaging in clinical practice. This review investigates the prevalence of endogenous hypercortisolism in patients with AIs and PIs. We aim to underscore the importance of early detection and management of endogenous hypercortisolism in this subset of patients to mitigate associated cardiometabolic complications and reduce mortality.

METHODS

We performed a PubMed literature search to provide updates regarding the prevalence of endogenous hypercortisolism in patients with AIs and PIs, the demographic and clinical characteristics of the studied populations, and the diagnostic test accuracy for early identification of endogenous hypercortisolism.

RESULTS

Hypercortisolism, especially mild autonomous cortisol secretion (MACS), was identified in a notable proportion of patients with AIs. MACS was associated with increased cardiometabolic risks, contributing to an elevated overall mortality rate in this cohort. Furthermore, PIs were found to be linked with Cushing's disease in a subset of patients, emphasizing the need for thorough evaluation and monitoring.

CONCLUSION

Early diagnosis and appropriate management of endogenous hypercortisolism are essential in preventing complications and improving patient outcomes. As the presence of undetected hypercortisolism is associated with clinical complications over time, the accurate identification of high-risk populations to screen remains crucial.

Cushing syndrome in paediatric population: who and how to screen

Cushing's syndrome (CS) is characterised by signs and symptoms resulting from excessive and prolonged exposure to exogenous glucocorticoids or endogenous hypercortisolism. In childhood, exogenous CS represents the main cause of CS due to the widespread therapeutic use of glucocorticoids, while endogenous CS is very rare and accounts for about 10% of CS cases. According to the origin of the hypercortisolism, the ACTH-dependent form due to pituitary ACTH-secreting tumours is the most common form of endogenous CS in paediatric age (about 75-80% of cases), following by adrenal causes (about 15-20% of cases) including adenoma, carcinoma (which has a peak of incidence in the first decade), bilateral adrenal hyperplasia or Carney complex, with a different distribution by age. Ectopic ACTH-secreting CS, genetic forms of pituitary adenomas are more uncommon. The insidious onset of hypercortisolism and the absence of salient early signs make the diagnosis of endogenous CS difficult. Facial changes, weight gain with simultaneous growth failure, prepubertal virilisation, or hypogonadism in adolescence represent some of the key features of CS. The diagnostic workup is essentially aimed at confirming hypercortisolism through screening tests whose diagnostic accuracy is not 100% and therefore the combination of more than two tests is mandatory to confirm the diagnosis of CS.

Screening for endogenous hypercortisolism in patients with osteoporosis and fractures: why, when and how

Skeletal comorbidities are frequent and clinically relevant findings in Cushing's syndrome (CS) since an uncoupled suppressed bone formation and enhanced bone resorption leads to a marked skeletal damage with a rapid increase of fracture risk. Reduced Bone Mineral Density (BMD) has been consistently reported and osteopenia or osteoporosis are typical findings in patients with CS. Vertebral Fractures (VFs) are frequently reported and may occur even in patients with an only mild reduction of BMD. Since CS is diagnosed late due to often difficult biochemical and radiological confirmation as well as to signs and symptoms common in other much more frequent diseases an approach suggested for overcoming underdiagnosis is to screen patients with manifestations which may overlap with those of CS such as arterial hypertension, diabetes mellitus and osteoporosis. Our review will focus on the rationale and best practice for screening osteoporotic patients for CS.

Hypertension and Cushing's syndrome: hunt for the red flag

INTRODUCTION

The prevalence of secondary hypertension is reported to be 5-15% of people with hypertension. Causes of secondary hypertension include Cushing's syndrome (CS), a rare but serious clinical condition characterized by chronic endogenous hypercortisolism associated with increased morbidity and mortality, especially for cardiovascular complications. The challenge for the clinician is thus to identify the phenotype of hypertensive patients who should be screened for endogenous hypercortisolism.

METHODS

This study was performed according to the PRISMA statement. The search was last updated in June 2023, and only English language studies were considered. Titles and abstracts have been screened for articles selection, identifying only those that dealt with prevalence of Cushing's syndrome in hypertensive patients. Finally, eight papers were included in the review. Data regarding year of publication, populations' characteristics, inclusion criteria, screening test and cut-off used, and CS prevalence have been extracted.

RESULTS

The study search identified eight studies, from 1977 to 2020, including a total number of 11,504 patients, ranging from 80 to 4429 patients for each study. The prevalence of CS reported was variable among the studies, ranging from 0 to 7.7%, having Cushing's disease (CD) a prevalence range of 0-1.2%. The highest prevalence has been found in selected populations of hypertensive patients younger than 40 years (6.2%) or harbouring an adrenal lesion (7.7%). The most used screening test was 1 mg overnight dexamethasone suppression test (1 mg DST), with different cut-off.

CONCLUSION

The most fitting CS profile encompasses younger age (i.e., < 40 years old), rapidly evolving hypertension and the presence of adrenal adenomas, along with subjects with pituitary lesions, who should still be prioritized in the diagnostic pathway. Overall, in the case of hypertensive patients presenting a clinical picture highly suggestive of CS, it is advisable to perform one of the available screening tests (UFC, 1 mg DST, LNSC). LNSC is likely the most discriminatory test and may be preferred, depending on its availability. Conversely, for hypertensive patients with an adrenal incidentaloma, the 1 mg DST is recommended as the screening test to exclude CS.

Development of diagnostic algorithm for Cushing's syndrome: a tertiary centre experience

PURPOSE

No consensus exists as the gold standard for Cushing's Syndrome (CS) screening. This study aimed to evaluate the diagnostic accuracy and utility of late-night salivary cortisol (LNSC) and cortisone (LNSE), overnight dexamethasone suppression test (ODST), and urinary free cortisol (UFC) in developing a screening algorithm for CS.

METHODS

A retrospective, single-centre analysis on 93 adult patients referred to the Oxford Centre for Diabetes, Endocrinology, and Metabolism for CS evaluation (2017-2022). Data were analysed using binomial logistic regression and area under the receiver-operating curve (AUROC).

RESULTS

Fifty-three patients were diagnosed with CS. LNSC (sensitivity 87.5%, specificity 64.9%, AUC 0.76), LNSE (sensitivity 72.4%, specificity 85.7%, AUC 0.79), and ODST (sensitivity 94.7%, specificity 52.1%; AUC 0.74) demonstrated comparable effectiveness for CS diagnosis. Their combined application increased diagnostic accuracy (AUC 0.91). UFC was not statistically significant. Pre-test clinical symptom inclusion improved screening test performance (AUC LNSC: 0.83; LNSE: 0.84; ODST: 0.82). For CD diagnosis, LNSE + LNSC (AUC 0.95) outperformed ODST. Combining these with ACTH levels < 12.6 pmol/L perfectly distinguished MACS (AUC 1.00). ODST (AUC 0.76) exhibited superior performance (sensitivity 100.0%, specificity 52.2%) in MACS detection.

CONCLUSIONS

LNSC, LNSE, and ODST are robust tools for CS screening, with their combined use offering the highest diagnostic precision. LNSE, especially when used with LNSC, is highly effective for CD diagnosis, exceeding ODST accuracy. ODST is preferable for MACS identification. Integrating ACTH levels markedly improves differentiation between CD and MACS. Conversely, UFC shows limited diagnostic utility.

Ionic liquid-caged nucleic acids enable active folding-based molecular recognition with hydrolysis resistance

Beyond storage and transmission of genetic information in cellular life, nucleic acids can perform diverse interesting functions, including specific target recognition and biochemical reaction acceleration; the versatile biopolymers, however, are acutely vulnerable to hydrolysis-driven degradation. Here, we demonstrate that the cage effect of choline dihydrogen phosphate permits active folding of nucleic acids like water, but prevents their phosphodiester hydrolysis unlike water. The choline-based ionic liquid not only serves as a universal inhibitor of nucleases, exceptionally extending half-lives of nucleic acids up to 6 500 000 times, but highly useful tasks of nucleic acids (e.g. mRNA detection of molecular beacons, ligand recognition of aptamers, and transesterification reaction of ribozymes) can be also conducted with well-conserved affinities and specificities. As liberated from the function loss and degradation risk, the presence of undesired and unknown nucleases does not undermine desired molecular functions of nucleic acids without hydrolysis artifacts even in nuclease cocktails and human saliva.

Different Types of Glucocorticoids to Evaluate Stress and Welfare in Animals and Humans: General Concepts and Examples of Combined Use

The main glucocorticoids involved in the stress response are cortisol and cortisone in most mammals and corticosterone in birds and rodents. Therefore, these analytes are currently the biomarkers more frequently used to evaluate the physiological response to a stressful situation. In addition, "total glucocorticoids", which refers to the quantification of various glucocorticoids by immunoassays showing cross-reactivity with different types of glucocorticoids or related metabolites, can be measured. In this review, we describe the characteristics of the main glucocorticoids used to assess stress, as well as the main techniques and samples used for their quantification. In addition, we analyse the studies where at least two of the main glucocorticoids were measured in combination. Overall, this review points out the different behaviours of the main glucocorticoids, depending on the animal species and stressful stimuli, and shows the potential advantages that the measurement of at least two different glucocorticoid types can have for evaluating welfare.

Confounding effects of liquorice, hydrocortisone, and blood contamination on salivary cortisol but not cortisone

Objective

To determine the effects of liquorice consumption, topical hydrocortisone, and blood contamination on salivary cortisol and cortisone concentrations.

Design and methods

Thirty healthy volunteers were randomized to a low, medium, or high dose of liquorice. Late-night saliva samples were collected using a Salivette® collection device at baseline, during 1 week of daily liquorice consumption, and during 4 weeks' washout. Saliva sampling was also performed before and after the application of topical hydrocortisone on the skin. Furthermore, in a subgroup (n = 16), saliva and venous blood were collected from each individual and mixed to achieve graded blood contamination in saliva. Salivary cortisol and cortisone were analyzed with liquid chromatography-tandem mass spectrometry.

Results

Significant increases in salivary cortisol concentrations were observed during medium- (+49%) and high-dose (+97%) liquorice intake, which returned to baseline 4 days after liquorice withdrawal. Topical hydrocortisone on fingers holding the collection swab increased salivary cortisol concentrations >1000-fold with concomitant pronounced elevation of the cortisol:cortisone ratio. Salivary cortisol increased significantly after contamination with blood ≥0.5%. Visual examination could safely detect these samples. Salivary cortisone concentrations were unaffected by liquorice consumption and blood contamination, and only marginally affected by topical hydrocortisone.

Conclusion

Liquorice, topical hydrocortisone, and blood contamination may all cause elevated salivary cortisol concentrations. Improved sampling instructions and visual examination of the sample may minimize these risks. Salivary cortisone is essentially unaffected by the different preanalytical confounders and may be used as a first-line screening test for Cushing's syndrome.

Simultaneous Measurement of Cortisol, Cortisone, Dexamethasone and Additional Exogenous Corticosteroids by Rapid and Sensitive LC-MS/MS Analysis

The simultaneous measurement of dexamethasone and cortisol has proven the ability to increase the diagnostic performance of the overnight dexamethasone-suppression test. Furthermore, the therapeutic drug monitoring of administered corticosteroid drugs could represent a crucial tool for investigating unexpected variations of steroid hormones' circulating levels. In this work, an LC-MS/MS method for the quantification of cortisol, cortisone, dexamethasone and six additional exogenous corticosteroids in the serum/plasma matrix was developed and validated in compliance with the ISO/IEC requirements. To assess the efficiency of the validated method, serum samples of 75 patients undergoing the dexamethasone-suppression test and 21 plasma samples of patients under immunosuppressive treatment after kidney transplant were analyzed. In all dexamethasone-suppression test samples, it was possible to measure the circulating levels of cortisol, cortisone and dexamethasone. Concentrations of the latter were for all tested patients above the proposed cutoff for the dexamethasone-suppression test's results, and the cortisol concentrations showed good correlation with the ones measured by routine immunometric analysis, therefore confirming the screening outcome for all enrolled patients. Prednisone was detected and quantified in all enrolled patients, confirming the use of such a corticosteroid for immunosuppressive therapy. Thanks to these two applications, we proved the overall performance of the developed LC-MS/MS method for four target analytes. The future implementation of such an analytical tool in the clinical biochemistry laboratory's routine will guarantee a single and versatile tool for simultaneously monitoring dexamethasone-suppression-test results and corticosteroid drugs' administration.

Molecular Derangements and the Diagnosis of ACTH-Dependent Cushing's Syndrome

Endogenous Cushing's syndrome (CS) is associated with morbidities (diabetes, hypertension, clotting disorders) and shortens life because of infections, pulmonary thromboembolism, and cardiovascular disease. Its clinical presentation is immensely variable, and diagnosis and treatment are often delayed. Thus, there are many opportunities for basic and clinical research leading to better tests, faster diagnosis, and optimized medical treatments. This review focuses on CS caused by excessive adrenocorticotropin (ACTH) production. It describes current concepts of the regulation of ACTH synthesis and secretion by normal corticotropes and mechanisms by which dysregulation occurs in corticotrope (termed "Cushing's disease") and noncorticotrope (so-called ectopic) ACTH-producing tumors. ACTH causes adrenal gland synthesis and pulsatile release of cortisol; the excess ACTH in these forms of CS leads to the hypercortisolism of endogenous CS. Again, the differences between healthy individuals and those with CS are highlighted. The clinical presentations and their use in the interpretation of CS screening tests are described. The tests used for screening and differential diagnosis of CS are presented, along with their relationship to cortisol dynamics, pathophysiology, and negative glucocorticoid feedback regulation in the two forms of ACTH-dependent CS. Finally, several gaps in current understanding are highlighted in the hope of stimulating additional research into this challenging disorder.

Recombinant Histidine-Tagged Nano-protein-based Highly Sensitive Electro-Sensing Device for Salivary Cortisol

We have developed a powerful biosensing strategy for immobilizing histidine-tagged (His-Tag)-oriented recombinant nano-protein immobilization on a chemically modified glassy carbon electrode (GCE) surfaces via (S)-N-(5-amino-1-carboxypentyl)iminodiacetic acid (ANTA) acting as a chelating Ni2+ centered interaction. Here, we introduce a label-free electro-sensor to quantify cortisol levels in saliva samples for point-of-care testing (POCT). The high specificity of the chemically modified GCE was established by genetically bio-engineered metal-binding sites on the selected recombinant apoferritin (R-AFTN) nano-protein to impart functionality to its surface and by coating the carbon surface with the self-assembled monolayers of 4-aminobenzoic acid (4-ABA) attached to ANTA groups complexed with Ni2+ transition metal ions. Despite the variety of conventional assays available to monitor cortisol levels, they require bulky exterior outfits, which hinders use in the healthcare systems. Therefore, we performed a rapid, easy-to-implement, and low-cost quantitative electro-sensor to enable the real-time detection of cortisol levels in saliva samples. As a result, the cortisol electro-sensor fabricated with high specificity utilizing a GCE could measure cortisol levels with a detection limit of 0.95 ng/ml and sensitivity of 7.91 μA/(ng/mL), which is a practical approach in human saliva. Thus, protein nanoprobe-based cortisol biosensing showed high sensitivity and selectivity for the direct electro-sensing of cortisol for POCT.

The diagnostic value of salivary cortisol and salivary cortisone in patients with suspected hypercortisolism

BACKGROUND

Diagnosing endogenous hypercortisolism remains a challenge, partly due to a lack of biochemical tests with good diagnostic accuracy.

OBJECTIVES

To evaluate the diagnostic value of salivary cortisol and cortisone in patients with suspected hypercortisolism.

METHODS

Retrospective study including 155 patients with adrenal incidentaloma, and 54 patients with suspected Cushing´s syndrome (CS). Salivary samples were collected at home, at 11 p.m., and at 8 a.m. following an over-night dexamethasone suppression test (DST). Salivary cortisol and cortisone were measured with liquid chromatography-tandem mass spectrometry.

RESULTS

Ten of 155 patients with adrenal incidentaloma were considered to have autonomous cortisol secretion (ACS). Using previously established cut-offs, all patients with ACS had elevated plasma-cortisol (>50 nmol/L) following DST, 9/10 had elevated late-night salivary cortisone (>15 nmol/L) whereas only 4/10 had elevated late-night salivary cortisol (LNSC; >3 nmol/L) compared to 35%, 9% and 8%, respectively, of the 145 patients with non-functioning adrenal incidentaloma. Six (60%) patents with ACS had elevated salivary cortisol and cortisone at 8 a.m. following DST compared to 9% and 8%, respectively, of patients with non-functioning adrenal incidentaloma. One of 6 patients with overt CS had a normal LNSC and one had normal late-night salivary cortisone, while all had increased salivary cortisol and cortisone following DST.

CONCLUSION

LNSC is not sufficiently sensitive or specific to be used for screening patients with suspected hypercortisolism. Instead, late-night salivary cortisone seems to be a promising alternative in patients with adrenal incidentaloma and salivary cortisone at 8 a.m. following DST in patients with suspected CS. Larger studies are needed to confirm these findings.

Fast accurate quantification of salivary cortisol and cortisone in a large-scale clinical stress study by micro-UHPLC-ESI-MS/MS using a surrogate calibrant approach

Cortisol and cortisone are common markers for stress and thus preferentially analyzed in matrices that allow non-invasive sampling such as saliva. Though the major drawback of immunoassays is lack of specificity due to cross reactivities, they are still most commonly used for quantification of steroid hormones. To overcome such problems, sensitive methods based on liquid chromatography-mass spectrometry are becoming more and more accepted as the golden standard for steroid bioanalysis as they achieve accurate quantification at trace levels for multiple analytes in the same run. Along this line, the aim of this study was the development of a new microflow UHPLC-ESI-MS/MS method for the measurement of salivary cortisol and cortisone, which due to its microflow regime provides enhanced sensitivity and is more ecofriendly. The developed method implemented sample preparation by Solid-Phase Extraction (SPE) in a 96-well plate format. Data acquisitions were carried out in MRM (multiple reaction monitoring) mode. The quantitative determination of endogenous compounds in saliva remains a challenge since analyte-free matrix is lacking. Hence, a surrogate calibrant approach with cortisol-d₄ andcortisone-¹³C₃ was applied for the target compounds in the presented method. A number of factors were optimized and the method validated. The lower limit of quantitation (LLOQ) was 72 and 62 pg mL^-1for cortisol and cortisone, respectively. Linear calibration was achieved in the range from 0.062 to 75.5 ng mL^-1for cortisol-d₄ and 0.072 to 44 ng mL^-1forcortisone-¹³C₃. The performance of the method was also evaluated via proficiency test for salivary cortisol. Finally, it was applied successfully to evaluate cortisol and cortisone concentrations in multiple batches in routine clinical stress study samples (4056 total injections with 1983 study samples). Moreover, the instrument performance (in particular retention time variability) within each batch, between different batches and lot-to-lot of 5 investigated capillary columns over time is described. The work documents that micro-UHPLC-ESI-MS/MS is suitable and robust enough to carry out a full clinical study with greater than 1000s of samples over an extended period if adequate internal standards can be used.

Development and validation of a sensitive LC-MS/MS method for simultaneous quantification of thirteen steroid hormones in human serum and its application to the study of type 2 diabetes mellitus

Endogenous steroid hormones with similar structure, poor content and high efficacy are difficult and vital to be quantitatively detected. In this study, a validated method was established for the simultaneous quantification of thirteen steroids in human serum, and applied to the study of type 2 diabetes mellitus (T2DM). An ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of thirteen steroid hormones in human serum, including androstenedione, corticosterone (B), cortisol (F), cortisone, 18-hydroxycortisol (18OHF), 11-deoxycorticosterone, 11-deoxycortisol, pregnenolone, progesterone, 17-hydroxyprogesterone, testosterone, androstanolone and estradiol. Under the optimum conditions, method was achieved with a BEH Shield RP18 column within 18 min. The lower limits of quantitation for steroids were 0.08-7.81 ng/mL. The intra- and inter-day precision for all the analytes were less than 15 %, and the accuracy ranged from -14.19 % to 12.89 % at three quality control levels. The proposed method, indicating high steady and sensitivity, was successfully applied to the quantification of thirteen steroids levels in serum from patients with T2DM and healthy individuals. The serum concentrations of 18OHF and F were significantly increased in the patients compared with the healthy individuals, while B was significantly decreased. The fold change was 1.98, 1.25 and 0.79 respectively. The ratio of 18OHF to B (18OHF/B) exhibited a 2.51-fold increase in T2DM patients and presented a more significant change. 18OHF/B was identified as a prospective serum marker, which deserves further attention.

A New Clinical Model to Estimate the Pre-Test Probability of Cushing's Syndrome: The Cushing Score

BACKGROUND

Hypercortisolism accounts for relevant morbidity and mortality and is often a diagnostic challenge for clinicians. A prompt diagnosis is necessary to treat Cushing's syndrome as early as possible.

OBJECTIVE

The aim of this study was to develop and validate a clinical model for the estimation of pre-test probability of hypercortisolism in an at-risk population.

DESIGN

We conducted a retrospective multicenter case-control study, involving five Italian referral centers for Endocrinology (Turin, Messina, Naples, Padua and Rome). One hundred and fifty patients affected by Cushing's syndrome and 300 patients in which hypercortisolism was excluded were enrolled. All patients were evaluated, according to current guidelines, for the suspicion of hypercortisolism.

RESULTS

The Cushing score was built by multivariable logistic regression, considering all main features associated with a clinical suspicion of hypercortisolism as possible predictors. A stepwise backward selection algorithm was used (final model AUC=0.873), then an internal validation was performed through ten-fold cross-validation. Final estimation of the model performance showed an average AUC=0.841, thus reassuring about a small overfitting effect. The retrieved score was structured on a 17.5-point scale: low-risk class (score value: ≤5.5, probability of disease=0.8%); intermediate-low-risk class (score value: 6-8.5, probability of disease=2.7%); intermediate-high-risk class (score value: 9-11.5, probability of disease=18.5%) and finally, high-risk class (score value: ≥12, probability of disease=72.5%).

CONCLUSIONS

We developed and internally validated a simple tool to determine pre-test probability of hypercortisolism, the Cushing score, that showed a remarkable predictive power for the discrimination between subjects with and without a final diagnosis of Cushing's syndrome.

Aptamer-Based Lateral Flow Biosensor for Rapid Detection of Salivary Cortisol

We have developed a disposable point-of-care (POC) aptamer-based biosensor for the detection of salivary cortisol. Nonstressful and noninvasive sampling of saliva compared to that of blood makes saliva an attractive biological matrix in developing POC devices for biomarker monitoring. Aptamers are attractive as recognition elements for multiple reasons, including their specific chemical synthesis, high stability, lack of immunogenicity, and cell-free evolution. A duplex aptamer conjugated to the surface of Au nanoparticles (AuNPs) by Au-S bonds is utilized as the sensor probe in a lateral flow assay (LFA) device. The addition of saliva samples containing cortisol makes the cortisol-aptamer undergo conformational changes and dissociate from the capture probe. Increasing cortisol concentration in the dispensed saliva sample results in increased dissociation and leads to increased binding of AuNP conjugate on the test line. Therefore, the color intensity of the test line on the LFA is a direct function of the concentration of cortisol in saliva. This simple and fast method provides detection in the cortisol range of ∼0.5-15 ng/mL, which is in the clinically accepted range for salivary cortisol. The limit of detection was 0.37 ng/mL, and the accuracy was confirmed by enzyme-linked immunosorbent assay (ELISA) testing results. High selectivity was observed for salivary cortisol against other closely related steroids and stress biomarkers present in saliva.