[Machine learning methods in differential diagnosis of ACTH-dependent hypercortisolism]

AIM

To develop a noninvasive method of differential diagnosis of ACTH-dependent hypercortisolism, as well as to evaluate the effectiveness of an optimal algorithm for predicting the probability of ectopic ACTH syndrome (EAS) obtained using machine learning methods based on the analysis of clinical data.

MATERIALS AND METHODS

As part of a single-center, one-stage, cohort study, a retrospective prediction of the probability of EAS among patients with ACTH-dependent hypercortisolism was carried out. Patients were randomly stratified into 2 samples: training (80%) and test (20%). Eleven machine learning algorithms were used to develop predictive models: Linear Discriminant Analysis, Logistic Regression, elastic network (GLMNET), Support Vector machine (SVM Radial), k-nearest neighbors (kNN), Naive Bayes, binary decision tree (CART), C5.0 decision tree algorithms, Bagged CART, Random Forest, Gradient Boosting (Stochastic Gradient Boosting, GBM).

RESULTS

The study included 223 patients (163 women, 60 men) with ACTH-dependent hypercortisolism, of which 175 patients with Cushing's disease (CD), 48 - with EAS. As a result of preliminary data processing and selection of the most informative signs, the final variables for the classification and prediction of EAS were selected: ACTH level at 08:00 hours, potassium level (the minimum value of potassium in the active stage of the disease), 24-h urinary free cortisol, late-night serum cortisol, late-night salivary cortisol, the largest size of pituitary adenoma according to MRI of the brain. The best predictive ability in a training sample of all trained machine learning models for all three final metrics (ROC-AUC (0.867), sensitivity (90%), specificity (56.4%)) demonstrated a model of gradient boosting (Generalized Boosted Modeling, GBM). In the test sample, the AUC, sensitivity and specificity of the model in predicting EAS were 0.920; 77.8% and 97.1%, respectively.

CONCLUSION

The prognostic model based on machine learning methods makes it possible to differentiate patients with EAS and CD based on basic clinical results and can be used as a primary screening of patients with ACTH-dependent hypercortisolism.

[Diagnostic value of bilateral inferior petrosal sinus sampling in various modifications and methods of radiation and radionuclide imaging in the diagnosis and differential diagnosis of ACTH-dependent endogenous hypercortisolism]

AIM

To analyze the diagnostic performance of bilateral inferior petrosal sinus sampling (BIPSS) with desmopressin as a stimulation agent and prolactin measurements to control catheter position with or without the ACTH/prolactin normalized ratio calculation in the differential diagnosis of ACTH-dependent endogenous hypercortisolism, and the diagnostics performance of ectopic ACTH-syndrome (EAS) visualization.

MATERIALS AND METHODS

A single-center diagnostic study with a retrospective analysis of the data was carried out. The study included patients with ACTH-dependent endogenous hypercorticism with no visualization of pituitary adenoma on MRI or adenoma sizes less than 6 mm. All patients underwent BIPSS with and without calculation of the ACTH/prolactin normalized ratio. Visualization of an EAS included pituitary MRI (to exclude EAS), whole-body CT scan with contrast, and somatostatin receptor scintigraphy with 99mTc-Tectrotide and CT (99mTc-Tectrotide SPECT). The final verification was based on immunohistochemical confirmation of the tumor or stable remission of Cushing's disease (CD) after surgical treatment. Statistical data processing was carried out by using IBM SPSS Statistics 23. Confidence intervals were calculated using the JavaStat online calculator.

RESULTS

230 BIPSS were performed in 228 patients (166 women, 62 men), of which 178 patients were verified as CD and 50 cases were EAS of various localization. The effectiveness of catheterization of petrosal sinuses was 96.9%. The sensitivity of BIPSS without ACTH/prolactin ratio calculation (n=70) was 95.9% (95% CI 86.3-98.9), specificity was 92% (95% CI 75.0-97.8), for the BIPSS with additional determination of ACTH/prolactin-normalized ratio (n=51) - 97.3% (95% CI 86.2-99.5) and 93.8% (95% CI 71.7-98.9), respectively. The use of the MRI method for this sample of patients had a sensitivity of 60.2% (95% CI 52.6-67.5), specificity of 59.2% (95% CI 44.2-73.0), the total body CT with contrast has a sensitivity of 74% (95% CI 59.7-85.4), specificity of 100% (95% CI 97.95-100). The diagnostic accuracy for 99mTc-Tectrotide SPECT in NET visualization has a sensitivity of 73.3% (95% CI 44.9-92.2), specificity of 100% (95% CI 95.3-100).

CONCLUSION

BIPSS with desmopressin stimulation and prolactin measurements to control catheter position, as well as the additional calculation of the ACTH/prolactin-normalized ratio, is an optimal method for the differential diagnosis of EAS. Patients who are identified an EAS on BIPSS may be further referred for 99mTc-Tectrotide SPECT and CT for tumor visualization.

Dynamics of NT-proBNP and ST2 levels as markers of heart failure in patients with endogenous Cushing syndrome (hypercortisolism)

Aim. To evaluate frequency of heart failure syndrome in patients with endogenous hypercortisolism and to establish relationship between effective treatment for hypercortisolism and regression of heart failure with particular emphasis on the observation of NT-proBNP and ST2 levels. Materials and methods. 56 patients with endogenous hypercortisolism (45 female, mean age 47 years [36; 55] hospitalized with endogenous hypercortisolism to National Medical Research Center for Endocrinology were enrolled in the study. All patients underwent comprehensive clinical investigation including expert echocardiography with speckle tracking and evaluation of NT-proBNP and ST2 cardiac biomarkers at baseline and 6 months after surgical treatment. Results. According to clinical data and elevated biomarkers of cardiac stress 28 out of 56 patients (50%) at baseline met the criteria for heart failure. 20 patients were included in the final analysis. Follow-up investigation with focus on changes in NT-proBNP and ST2 levels demonstrated that surgical correction of endogenous hypercortisolism resulted in resolution of heart failure syndrome in 11 patients (55%). Conclusion. These preliminary data suggest that signs and symptoms of heart failure are observed in patients with endogenous hypercortisolism in about half the cases. Surgical correction results in resolution of heart failure in approximately two thirds of the cases. Prospective evaluation NT-proBNP and ST2 levels may provide important diagnostic and prognostic information in patients with endogenous hypercortisolism.

[Survival predictors in patients with ectopic acth syndrome]

AIM

To determine significant factors affecting the survival of patients with ectopic ACTH syndrome (EAS).

MATERIALS AND METHODS

A multi-center, observational study with a retrospective analysis of patients with EAS. The end point of the study was the fatal outcome of patients from various causes. In order to identify predictors of survival or mortality, univariate and multifactorial Cox regression analyses were carried out. ROC-analysis was used to determine the prognostic threshold values of individual predictors. The survival analysis was carried out using the Kaplan-Mayer method. Statistical data processing was carried out by using IBM SPSS Statistics 23.

RESULTS

The age of patients at the time of diagnosis ranged from 12 to 76 years (Me 40 years [28;54]). The age of the studied population was 55 years [38; 64] for women and 42 years [32; 54] for men. The median period of observation was 50 months [13;91], with a maximum follow-up of 382 months. 92 patients (60,9%) had bronchopulmonary NET, 17 (11,3%) - thymic carcinoid, 8 - pancreatic NET, 5 -pheochromocytoma, 1- cecum NET, 1- appendix carcinoid tumor, 1 - medullary thyroid cancer and 26 (17,2%) patients had an occult NET. The primary tumor was removed in 101 patients (66,9%). Bilateral adrenalectomy was performed in 42 (27,8%) cases. Metastases were revealed in 23,2% (n=35) of patients. Relapse of the disease was observed in 24,4%, long-term remission was preserved in 64 patients (74,4%). Death occurred in 42 patients (28%). The average age of survivors was 47,0±15,2 versus 53,5±15,6 years for the deceased (p=0,022). The average survival time from diagnosis for the deceased was 32 months, Me 16,5 months [7;54]. Multivariate analysis revealed that the following factors have a direct impact on survival: age of diagnosis ≥51 years (OR 4,493; 95% CI 2,056-9,818, p<0,001), bronchopulmonary neuroendocrine tumor (NET) (OR 0,281; 95% CI 0,119-0,665, p=0,004), the presence of distant metastases (OR 2,489; 95% CI 1,141-5,427, p=0,022), late-night salivary cortisol (LNSC) ≥122,2 nmol/L (OR 2,493; 95% CI 1,014-6,128, p=0,047).

CONCLUSION

The prognosis of patients with EAS is influenced by the age of diagnosis, NET localization, distant metastases and level of LNSC. The most common cause of ectopic ACTH syndrome was bronchopulmonary NET which was associated with the best survival rate.

[A clinical Case and brief literature review of Icenko-Cushing's Disease in a pediatric patient with atypical onset of the disease]

Itsenko-Cushing's disease is a rare, multisystem disease characterized by the presence of endogenous central hypercortisolism due to an ACTH-secreting brain tumor. The frequency of Itsenko-Cushing's disease in adulthood is 0.7-2.4 per 1 million population, and only 10% of all cases occur in childhood. The age of onset of the disease in children is on average 12.0-14.8 years. A typical manifestation of the disease in children, along with obesity and arterial hypertension, is a decrease in growth rates. The gold standard for diagnosing central hypercortisolism is MRI of the brain, however, the effectiveness of this method in children is only 50%. The main method of treatment is neurosurgical transnasal transsphenoidal removal of endosellar pituitary adenoma, which makes it possible to achieve remission in more than 65% of cases. This article describes a clinical case of Itsenko-Cushing's disease in a 6.5-year-old child with obesity, arterial hypertension, atypically «high» stature, average velocity and non-visualizable corticotropinoma. The article presents the stages of diagnostic search, the complexity of differential diagnosis and surgical treatment, the results of follow-up after the treatment and a brief review of the literature.

Assessment of Vitamin D Metabolism in Patients with Cushing's Disease in Response to 150,000 IU Cholecalciferol Treatment

In this study we aimed to assess vitamin D metabolism in patients with Cushing’s disease (CD) compared to healthy individuals in the setting of bolus cholecalciferol treatment. The study group included 30 adults with active CD and the control group included 30 apparently healthy adults with similar age, sex and BMI. All participants received a single dose (150,000 IU) of cholecalciferol aqueous solution orally. Laboratory assessments including serum vitamin D metabolites (25(OH)D₃, 25(OH)D₂, 1,25(OH)₂D₃, 3-epi-25(OH)D₃ and 24,25(OH)₂D₃), free 25(OH)D, vitamin D-binding protein (DBP) and parathyroid hormone (PTH) as well as serum and urine biochemical parameters were performed before the intake and on Days 1, 3 and 7 after the administration. All data were analyzed with non-parametric statistics. Patients with CD had similar to healthy controls 25(OH)D₃ levels (p > 0.05) and higher 25(OH)D₃/24,25(OH)₂D₃ ratios (p < 0.05) throughout the study. They also had lower baseline free 25(OH)D levels (p < 0.05) despite similar DBP levels (p > 0.05) and lower albumin levels (p < 0.05); 24-h urinary free cortisol showed significant correlation with baseline 25(OH)D₃/24,25(OH)₂D₃ ratio (r = 0.36, p < 0.05). The increase in 25(OH)D₃ after cholecalciferol intake was similar in obese and non-obese states and lacked correlation with BMI (p > 0.05) among patients with CD, as opposed to the control group. Overall, patients with CD have a consistently higher 25(OH)D₃/24,25(OH)₂D₃ ratio, which is indicative of a decrease in 24-hydroxylase activity. This altered activity of the principal vitamin D catabolism might influence the effectiveness of cholecalciferol treatment. The observed difference in baseline free 25(OH)D levels is not entirely clear and requires further study.

[Differences in plasma miRNA levels in inferior petrosal sinus samples of patients with ACTH-dependent Cushing's syndrome]

BACKGROUND

For the last decades microRNAs (miR) have proven themselves as novel biomarkers for various types of diseases. Identification of specific circulating microRNA panel that differ patient with Cushing's disease (CD) and ectopic ACTH syndrome (EAS) could improve the diagnostic procedure.

AIM

to evaluate the differences in miR levels in plasma samples drained from inferior petrosal sinuses in patients with CD and EAS.

MATERIALS AND METHODS

single-center, case-control study: we enrolled 24 patients with ACTH-dependent Cushing's syndrome (CS) requiring bilateral inferior petrosal sinus sampling (BIPSS).  Among them 12 subjects were confirmed as CD (males=2, females=10; median age 46,5 [IR 33,8;53,5]) and 12 as EAS (males=4, females=8, median age 54 [IR 38,75;60,75]). BIPSS was performed through a percutaneous bilateral approach. Once catheters were properly placed, blood samples were withdrawn simultaneously from each petrosal sinus and a peripheral vein. Plasma samples from both sinuses were centrifuged and then stored at -80 C. MiRNA isolation from plasma was carried out by an miRneasy Plasma/Serum Kit (Qiagen, Germany) on the automatic QIAcube station according to the manufacturer protocol. To prevent degradation, we added 1 unit of RiboLock Rnase Inhibitor (Thermo Fisher Scientific, USA) per 1 μL of RNA solution. The concentration of total RNA in the aqueous solution was evaluated on a NanoVue Plus spectrophotometer (GE Healthcare, USA). The libraries were prepared by the QIAseq miRNA Library Kit following the manufacturer standard protocols. MiR expression was then analyzed by sequencing on Illumina NextSeq 500 (Illumina, USA).

RESULTS

108 miRNAs were differently expressed (p &lt;0,05) in inferior petrosal sinus samples of patients with CD vs EAS. We divided these miRNAs into 3 groups based on the significance of the results. The first group consisted of samples with the highest levels of detected miR in both groups. Four miRNAs were included: miR-1203 was downregulated in CD vs EAS - 36.74 (p=0,013), and three other were upregulated in CD vs EAS: miR-383-3p 46.36 (p=0,01), miR-4290 6.84 (p=0,036), miR-6717-5p 4.49 (p=0,031). This miRs will be validated in larger cohorts using RT-qPCR.

CONCLUSION

Plasma miR levels differ in inferior petrosal samples taken from patients with CD vs EAS. These miRs need to be validated by different methods and in peripheral plasma samples in order to be used as potentially non-invasive biomarkers to differentiate ACTH-dependent CS.

Clinical course and outcome of patients with ACTH-dependent Cushing's syndrome infected with novel coronavirus disease-19 (COVID-19): case presentations

OBJECTIVE

To analyze the clinical presentations of patients with endogenous Cushing's syndrome (CS) affected by Coronavirus disease-19 (COVID-19).

MATERIALS AND METHODS

Patients who were referred to our clinic with active CS from 31st March to 15th May 2020 were screened for COVID-19 using real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Late-night serum cortisol (64-327 nmol/L), late-night salivary cortisol (LNSC) (0.5-9.4 nmol/L), or 24-h urinary free cortisol (24 hUFC) (100-379 nmol/24 h) were measured by electrochemiluminescence immunoassay.

RESULTS

Among 22 patients with active CS we found three cases affected by COVID-19. Nonspecific inflammation markers were within the reference range or slightly elevated in these patients. A 71-year-old woman with newly diagnosed CS (late-night serum cortisol >1750 nmol/L, LNSC 908.6 nmol/L) developed dyspnea as an only symptom and died from bilateral polysegmantal hemorrhagic pneumonia 7 days later. A 38-year-old woman with a 5-year medical history of active Cushing's disease (CD) (late-night serum cortisol 581.3 nmol/L, 24 hUFC 959.7 nmol/24-h) suffered from dyspnea, cough, fever (39.3 °C) and chest pain. Oxygen therapy, antibiotics and symptomatic treatments lead to full recovery 24 days later. A 66-year-old woman with a 4-year medical history of mild CD (late-night serum cortisol 603.4 nmol/L, LNSC 10.03 nmol/L) tested positive for COVID-19 in routine screening and remained asymptomatic.

CONCLUSIONS

The outcome of COVID-19 in patients with CS depends on the severity of hypercortisolism. Thus, severe hypercortisolism is a warning sign that CS affected by COVID-19 could require emergency care despite a lack of clinical presentations and low inflammation biomarkers.

[Pituitary microadenomas - current diagnostic and treatment methods]

According to previously accepted criteria, pituitary microadenoma is characterized by a diameter of less than 10 mm. Improvement and widespread use of MRI are accompanied by increased incidence of diagnosis of these neoplasms. Pituitary microadenomas is an extremely heterogeneous group of tumors with different biological behavior, endocrine secretion and clinical symptoms despite the common MR characteristics. Treatment is mainly determined by endocrine secretion. Endocrine-active microadenoma requires medication (in case of microprolactinoma) and surgical treatment (in case of microsomatotropinoma and ACTH-releasing tumor). Follow-up is advisable for endocrine-inactive microadenoma (microincidentaloma). Modern data on the incidence, clinical and endocrine features, diagnosis and treatment of various pituitary microadenomas are discussed in the article.

[The combination of classical tests and methods of chromatography for laboratory diagnostics of cushing's syndrome of different genesis.]

Immunochemical methods of analysis are traditionally used for diagnosis of various forms of Cushing's syndrome (CS). In the presence of boundary values of hormonal parameters, doubtful situations, a combination of changes both in pituitary and in adrenal glands, it is useful to determine additional differential diagnostic criteria for the diagnosis of various forms of CS. Urinary steroid profiles (USP) were analyzed by gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) for 38 females with adrenal Cushing's syndrome (CSA), 42 females with pituitary CS (CSP) and 25 healthy females (control group). An increase of free cortisol/free cortisone ratio in the urine (UFF/UFE) for CSP patients in comparison of CSA was obtained by HPLC method. Decreased urinary excretion of UFF and UFE by more than 60% after the 8 mg dexamethasone suppression test had 100% sensitivity and specificity of more than 90% for the diagnosis of CSP. GC-MS method in patients with CSA and CSG revealed the peculiarities of androgens, progestins and glucocorticoids metabolism which leaded to obtain specific USP for CS of different genesis. Increased urinary excretions of dehydroepiandrosterone and its metabolites, metabolites of androstenedione, the ratio of sum of cortisol and cortisone tetrahydrometabolites to tetrahydro-11-deoxycortisol (more then 36) in CSP patients compared with CSA are additional signs for differential diagnosis of these diseases. The combination of classical tests and USP obtained by HPLC and GC-MS methods increased the sensitivity and specificity of differential diagnosis of CSA and CSP.

Prediction of recurrence and remission within 3 years in patients with Cushing disease after successful transnasal adenomectomy

BACKGROUND

Some laboratory and clinical features are associated with a probability of recurrence after transnasal adenomectomy for Cushing disease (CD). However, there is no consensus on a set of predictors. Rules for prediction of recurrence were not proposed earlier.

AIM

To develop prediction model of recurrence/remission after successful neurosurgical treatment for CD.

METHODS

Retrospective single-site comparative study included 349 patients (52 men and 297 women) with a verified diagnosis of CD who underwent effective endoscopic transsphenoidal adenomectomy between 2007 and 2014. Clinical and laboratory parameters were evaluated. Laboratory tests were performed using immunochemiluminescent method. Time-to-event analysis and ROC-analysis were applied. Multivariate models were developed using logistic regression and artificial neural network (ANN).

RESULTS

Postoperative cortisol and ACTH levels and their combinations cannot be used for prediction of recurrence. ANN for prediction of recurrence within 3 years after successful surgery was developed. Input variables are age, duration of the disease, MRI data on adenoma, morning postoperative levels of ACTH and cortisol, output variable is binary (recurrence/remission). Predictive value for remission is 93%, 95% CI [89%; 96%], and predictive value for recurrence is 85%, 95% CI [71%; 94%]. Web-calculator based on the model is developed and free for use.

CONCLUSION

Effective method for prediction of recurrence and long-term remission within 3 years after successful endoscopic transsphenoidal adenomectomy is proposed.

Factors predicting the outcomes of removal of corticotropinom in Cushing's disease

Обоснование. Болезнь Иценко–Кушинга (БИК) – тяжелое многосимптомное заболевание гипоталамо-гипофизарно-надпочечниковой системы. Причиной заболевания является наличие аденомы гипофиза (кортикотропиномы). Увеличение секреции адренокортикотропного гормона (АКТГ) аденомой гипофиза приводит к повышенной секреции кортизола корой надпочечников и развитию тотального эндогенного гиперкортицизма. Золотым стандартом лечения данного заболевания является хирургическое удаление кортикотропиномы. Однако аденомэктомия не во всех случаях бывает эффективной, и примерно в 20% случаев после проведенного радикального лечения не удается достичь ремиссии заболевания и возникает рецидив. Цель. Целью нашей работы являлась оценка факторов, оказывающих влияние на результат аденомэктомии у пациентов с болезнью Иценко–Кушинга, и выявление предикторов рецидива. Методы. В исследование было включено 84 пациента (80 женщин и 4 мужчин) в возрасте от 18 до 58 лет с БИК до и после трансназальной аденомэктомии. Период наблюдения от 3 до 15 лет, начиная с 2001 г. (в среднем 9,0 лет). Была проведена ретроспективная оценка клинических и гормональных факторов (АКТГ и кортизола) до операции и через 1–3 и 8–13 дней после операции. Результаты. У 54 (64,3%) из 84 пациентов с БИК после проведенной трансназальной аденомэктомии развилась ремиссия заболевания. Оперативное лечение было неэффективно у 30 (35,7%) пациентов, и им была проведена повторная аденомэктомия. По данным МРТ головного мозга, среди пациентов с ремиссией заболевания чаще встречались микроаденомы гипофиза (54%) по сравнению с пациентами, у которых операция оказалась неэффективна, а на МРТ чаще встречались макроаденомы (63%). У всех больных с БИК независимо от исхода нейрохирургической операции наблюдалось достоверное снижение уровня кортизола и АКТГ в раннем послеоперационном периоде. Заключение. Показателями эффективности аденомэктомии и длительной ремиссии у пациентов с БИК являются уровень утреннего кортизола менее 100 нмоль/л и уровень АКТГ менее 10,0 пг/мл на ранних сроках после операции (1–13-й дни). Наличие надпочечниковой недостаточности после аденомэктомии является предиктором эффективности операции, но не исключает вероятности развития рецидива.

Effects of Intraperitoneal Administration of Mifepristone on Glucocorticoid Status of Experimental Animals

We studied the content of corticosterone and its precursors in the adrenal glands, corticosterone in blood serum and daily urine of rats, and activity of first and second isoforms of 11β-hydroxysteroid dehydrogenase in the liver and kidneys of rats after 15 daily intraperitoneal injections of 0.9% NaCl or glucocorticoid receptor blocker mifepristone in 0.9% NaCl. Daily injections of NaCl reduced the levels of pregnenolone, progesterone, and corticosterone in the adrenal glands, increased corticosterone excretion with urine, enhanced activity of the first isoform of 11β-hydroxysteroid dehydrogenase in the liver and reduction in activity of the second isoform of this enzyme in the kidneys. These changes are typical manifestations of chronic stress. Mifepristone restored pregnenolone content in the adrenal glands and increase in corticosterone concentration in the blood. Under these conditions, activity of the first isoform of 11β-hydroxysteroid dehydrogenase in the liver did not change, and a decrease in activity of the second isoform of the enzyme in the kidneys was less pronounced. The results suggest that mifepristone abolished the stress-mediated increase in activity of the first isoform of 11β-hydroxysteroid dehydrogenase in the liver and reduced local production of glucocorticoid hormones and their metabolic effects in hepatocytes.