Poisk soputstvuyushchih autoimmunnyh zabolevanij (AIZ) u pacientov s celiakiej yavlyaetsya aktual'noj zadachej. Cel'yu issledovaniya bylo opredelit' chastotu nositel'stva antitel (AT) — markerov razvitiya AIZ u pacientov s celiakiej s pomoshch'yu razlichnyh immunologicheskih podhodov. U pacientov s celiakiej (gruppa 1, n = 27) i zdorovyh lic (gruppa 2, n = 16) v syvorotke krovi s ispol'zovaniem IFA i metoda mul'tipleksnogo immunoanaliza (MI) na gidrogelevom biochipe opredeleny AT k tireoidnoj peroksidaze (TPO), tireoglobulinu (TG), glutamatdekarboksilaze (GAD), ostrovkovym kletkam podzheludochnoj zhelezy (ICA), tirozinfosfataze (IA2), 21-gidroksilaze (P450c21), vnutrennemu faktoru Kastla, tkanevoj transglutaminaze (TGM2). Biochip takzhe pozvolyaet provodit' issledovanie AT k interferonam (IFN) al'fa i omega, interlejkinu 22. Metodom IFA v gruppe 1 vyyavleny AT k IA2 (30%), TPO (22%), TG (19%), GAD (19%), v gruppe 2 — k IA2 (38%), TPO (19%), GAD (19%). V gruppe 1 s ispol'zovaniem biochipa obnaruzheny AT k TPO (11%), TG (11%), P450c21 (4%), IFN-al'fa (4%), ICA (4%), v gruppe 2 — k TPO (13%), ICA (13%), TG (6%), IFN-al'fa (6%). Znachimyh razlichij v chastote povysheniya AT v gruppah ne vyyavleno (p > 0,05). U pacientov s nositel'stvom AT, vyyavlennyh na biochipah, pri otricatel'nom rezul'tate IFA ne isklyuchaetsya razvitie AIZ v otsrochennom periode, chto pozvolyaet predpolozhit' prognosticheskuyu znachimost' MI. Otsutstvie znachimyh razlichij v chastote povysheniya AT sredi pacientov s celiakiej i zdorovyh lic mozhet byt' obuslovleno ogranichennoj chislennost'yu grupp nablyudeniya i svidetel'stvovat' o vysokoj rasprostranennosti potencial'nyh form AIZ v dannyh kogortah.

This study investigated the IgA antibodies targeting bovine serum albumin (BSA) in 27 adult celiac disease (CD) patients adhering to a gluten-free diet (GFD), compared to 123 controls (including individuals with autoimmune disorders, those with gastrointestinal cancers, and healthy donors). Serum samples were evaluated using a multiplex assay based on a microarray comprising 66 immobilized antigens, including autoantigens associated with autoimmune diseases, different albumins, cytokines, and inflammatory markers. Elevated IgA-BSA levels were detected in 22% of CD patients versus 3.25% of controls. IgA-BSA did not cross-react with milk proteins like casein, β-lactoglobulin, and γ-globulin, nor with autoantigens and human albumin, ruling out autoimmunity against self-proteins. The observed cross-reactivity with porcine albumin suggests that antibodies target epitopes shared by bovine and porcine albumin. Increased IgA-BSA levels may interfere with immunoassays performed using BSA as a stabilizer, necessitating protein-free buffers to avoid false results when testing CD patients. Elevated IgA-BSA levels may reflect ongoing gut barrier dysfunction in CD patients on a GFD, allowing dietary proteins like BSA to trigger immune responses. This study identifies a novel immune response in CD patients on a GFD, emphasizing the need for tailored diagnostic approaches (BSA-free assays) and further research into the clinical and dietary implications of IgA-BSA elevation.

BACKGROUND: Currently, an annual study of venous glucose after night fasting is carried out to detect hypoglycemia for diagnosis the recurrence of insulinoma. However, hypoglycemia cannot always be achieved after night fasting if tumor is small. Previously continuous glucose monitoring (CGM) in diagnosis of recurrence of insulinoma was evaluated in small samples. AIM: To evaluate the effectiveness of CGM in interstitium for the diagnosis of recurrent insulinoma (hypoglycemia) after surgery. METHODS: Adult patients who underwent surgery for insulinoma and with remission in the early postoperative period were included. The glucose level in the interstitium was studied by CGM for a maximum of 14 days, and a single venous blood glucose test was performed after a night fasting. If hypoglycemia was detected by any method, a long-term fasting test to confirm the recurrence of hypoglycemic syndrome and imaging diagnostics to identify insulinoma were performed. RESULT: The study included 29 patients after surgical treatment of insulinoma 3-69 months ago. Normoglycemia was determined in 28 patients after night fasting, while one had hypoglycemia, subsequently confirmed by a long-term fasting test. During the CGM, 25 patients had normoglycemia throughout the entire study period, while hypoglycemia was detected in 4 patients, and among them subsequent long-term fasting test confirmed it in three cases. During instrumental examination, pancreatic formation, different in location from the primary tumor, was detected in these three patients. Thus, the sensitivity of CGM relative to reference night fasting test is 100%, 95% CI (3%; 100%), specificity 89% (72%; 98%), positive predictive value 25% (1%; 81%), negative predictive value 100% (86%; 100%). During CGM no adverse events were detected. CONCLUSIONS: CGM can be used effectively and safely to rule out hypoglycemia; and positive cases require subsequent long-term fasting test.

Background/Objectives: The aim of this study was to evaluate the avidity of thyroid autoantibodies (Abs) in sera of patients with autoimmune thyroid disease (AITD) and thyroid autoantibody carriers without diagnosed AITD. Methods: A hydrogel microarray-based multiplex assay with the chaotrope destruction stage was developed to measure the avidity of thyroid disease-associated autoantibodies, including those targeting thyroperoxidase (TPO), thyroglobulin (Tg), and other minor antigens. Results: Evaluation of the assay in three independent cohorts of patients, totaling 266 individuals with and without AITD, demonstrated the heterogeneous avidity of autoantibodies to thyroid proteins. For the confirmation study, the median avidity index (AI) for AbTg was 29.9% in healthy autoantibody carriers, 52.6% for AITD patients, and 92.7% for type 1 diabetes (T1D) thyroid autoantibody carriers. The median AI for AbTPO was 39.9% in healthy carriers, 73.4% in AITD patients, 83.2% in T1D thyroid autoantibody carriers, and 98.5% in AITD patients with thyroid neoplasm. In patients with Hashimoto’s thyroiditis and known disease duration, changes in the avidity maturation of AbTPO over time were demonstrated. Conclusions: Longitudinal studies of TPO- and/or Tg-positive healthy individuals (with an interval of 1–2 years between visits) are needed to evaluate the maturation of autoantibody avidity during the asymptomatic phase and to assess the potential of autoantibody avidity as a prognostic marker for disease development.

The search for concomitant autoimmune disorders (ADs) in patients with celiac disease is a pressing issue. The study aimed to determine the rate of the carrier state for antibodies (Abs) being the markers of AD development in patients with celiac disease using various immunological approaches. Enzyme-linked immunoassay and hydrogel microarray-based multiplex immunoassay (MI) were used to determine Abs against thyroid peroxidase (TPO), thyroglobulin (TG), glutamate decarboxylase (GAD), pancreatic islet cells (ICA), tyrosine phosphatase (IA2), 21-hydroxylase (P450c21), Castle's intrinsic factor, tissue transglutaminase (TGM2) in blood serum of patients with celiac disease (group 1, n = 27) and healthy individuals (group 2, n = 16). The microarray also enables testing of Abs against interferons (IFN) alpha and omega, interleukin 22. In group 1, Abs against IA2 (30%), TPO (22%), TG (19%), GAD (19%) were detected by the enzyme-linked immunoassay, and in group 2 Abs against IA2 (38%), TPO (19%), GAD (19%) were detected. In group 1, Abs against TPO (11%), TG (11%), P450c21 (4%), IFN-alpha (4%), ICA (4%) were detected using the microarray, and in group 2 Abs against TPO (13%), ICA (13%), TG (6%), IFN-alpha (6%) were identified. No significant differences in the rate of elevated Abs in the groups were revealed (p > 0.05). Patients, in whom the Ab carrier state was established using microarrays, with negative results enzyme-linked immunoassay can develop the delayed ADs, which suggests prognostic value of MI. The lack of significant differences in the rate of elevated Abs in patients with celiac disease and healthy individuals can result from small size of the studied groups and can suggest high prevalence of potential AD forms in these cohorts.

Background: Insulinoma is a neuroendocrine tumor (NET), with its main clinical manifestation being the hypoglycemic syndrome. The symptoms of hypoglycemia are nonspecific, and therefore, in most cases, the diagnosis is made untimely. The Russian clinical guidelines for the diagnosis and treatment of NET suggest as a diagnostic test that the universal circulating marker of all NET, chromogranin A (CgA) be determined. However, the literature data on the sensitivity of CgA in the diagnosis of insulinoma are contradictory. Aim: To evaluate the diagnostic effectiveness of the CgA test in the diagnosis of insulinoma. Materials and methods: This was a hospital-based single-center, cross-sectional comparative (first step) and prospective non-comparative (second step) study conducted from 2016 to 2022. During the first part of the study, we determined serum CgA in 120 patients with suspected non-diabetic hypoglycemia and compared its levels in the patients with and without confirmed insulinoma (n = 87 and n = 33, respectively). During the second study step, CgA was measured in the insulinoma patients at 6 [4.0; 7.0] months after surgery. The CgA levels at baseline and post-surgery were analyzed in 74 patients (those with recurring non-diabetic hypoglycemia were excluded from the analysis). Results: In the study subjects without insulinoma, the median CgA level was 0.7 [0.5; 1.1] (range, 0.1 to 2.0) nmol/l and the difference (with Bonferroni adjustment) from its levels in the patients with insulinoma before surgery was non-significant (1.0 [0.7; 1.4], range, 0.1 to 8.5 nmol/l, р = 0.045). The CgA concentration in the insulinoma patients after surgery was 0.9 [0.7; 1.2], range, 0 to 1.9 nmol/l and significantly differed from that at baseline (1.0 [0.7; 1.4], range, 0.1 to 8.5 nmol/l, p = 0.012, Wilcoxon test). In the patients with insulinoma before surgery the CgA levels exceeding the generally accepted reference range ( 2 nmol/l) was found in 11.5% (n = 10), with its median level of 2.5 [2.3; 4.1], range 2.3 to 8.5 nmol/l. There were no significant associations between the CgA levels and localization, tumor numbers, their size and malignization grade, insulin and proinsulin values, and duration of fasting. The sensitivity and specificity of the CgA test were 12% [95% confidence interval [CI]: 6%–20%] and 100% [95% CI: 97%–100%], respectively. The prognostic value of a positive result (PVPR) was 100% [95% CI: 69%–100%] and the prognostic value of a negative result (PVNR) 30% [95% CI: 28%–32%]. Conclusion: As a diagnostic test, CgA has high specificity and prognostic value of a positive result. However, the uncertainty of the prognostic value of a negative result is unacceptably high. A special study is required to clarify the operational characteristics of CgA in insulinoma.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

The syndrome of apparent mineralocorticoid excess (AME) is a rare genetic disease characterized by juvenile hypertension, hypokalemia, suppression of renin and aldosterone. AME syndrome is caused by a mutation in the HSD11B2 gene, which encodes 11ß-hydroxysteroid dehydrogenase type 2, that converts cortisol into cortisone.The purpose of the article is to describe a clinical case of genetically confirmed (mutation C.911A>G of the HSD11B2 gene) AME syndrome. The disease manifested in the first years of life; the patient was prescribed mineralocorticoid receptor antagonists, potassium preparations, potassium-sparing diuretics, and other antihypertensive therapy. Due to the absence of normotonia and normokalemia, dexamethasone has been prescribed since the age of 12. Due to uncontrolled arterial hypertension and hypokalemia, complications developed (medullary nephrocalcinosis, myocardial remodeling), and prolonged dexamethasone intake led to a slowdown in puberty and a decrease in bone mineral density.

BACKGROUND:Insulinoma is a neuroendocrine tumor, the main manifestation of which is hypoglycemia. However, the symptoms of hypoglycemia can be non-specific for a long time, especially outside provocative conditions, and quite often the tumor manifests from a life-threatening condition - hypoglycemic coma. In this regard, timely laboratory diagnosis of insulinoma and determination of its aggressive course is one of the priorities in modern researches. AIM:Search for new immunohistochemical (IHC) and circulating markers (CM) of insulinoma, including its aggressive course. MATERIALS AND METHODS:The patients examined at the Endocrinology Research Centre in the period 2017-2022 and operated on for an insulin-producing tumor were included. Before surgery and 2-12 months after it, blood sampling was performed with the determination of targeted marker proteins. Some patients underwent an extended IHC examination of the tumor, surrounding tissue and islets of Langerhans with primary antibodies to target marker proteins with an assessment of the degree of their expression. To determine the aggressive course of the tumor, the degree of malignancy (Grade), the number of tumors and signs of recurrence were characterized. RESULTS:Based on the analysis of literature and pathogenetic characteristics of insulinoma, the following candidates for targeted marker proteins were selected: cocaine and amphetamine-regulated transcript (CART), chromogranin B (CrB), neuroendocrine secretory protein 55 (NESP55), glucagon-like peptide 1 (GLP1), arylalkylamine-N-acetyltransferase (AA-NAT), melatonin, and, exclusively for IHC research, protein D52 (TPD52), as well as receptors for glucagon-like peptide-1 (rGLP1) and melatonin (MTNR1b). 41 patients were included in the study, of which 10 patients underwent an extended IHC study. In patients with both aggressive and non-aggressive insulinoma after surgical treatment, CM levels did not change significantly and in individual patients they could both increase and decrease, including those patients with the expression of the corresponding marker in tumor tissue. It was shown that CART was expressed only in the tumor (in 4/10 of cases), while MTNR1b and rGLP1 were expressed in the tumor (in 6/10 and 10/10, respectively) and the islets of Langerhans (in 5/9 and 9/9, respectively). The association of marker expression with the aggressiveness of the course of insulinoma has not been revealed. CONCLUSION:The markers CART, MTNR1b and rGLP1 are of primary interest for further study in a larger sample of patients with insulinoma. Other markers (TPD52, XgB, NESP55, melatonin, AA-NAT) have not been shown to be associated with an insulin-producing tumor, therefore they are not promising for future researches. At the same time, it is necessary to continue research aimed at finding new both circulating and IHC markers in order to early diagnose the manifestation of the disease and its recurrence, and more accurately determine the malignant and proliferative potential of the tumor.

Autoimmune adrenal insufficiency (AAI) is a rare disease. This research evaluates three patients with AAI, including autoimmune polyglandular syndrome (APS) type 2. Two patients had APS or AAI during childhood, and one had a history of endocrine autoimmune disease, indicating a possible hereditary basis of the condition. Trio-based exome sequencing and high-resolution HLA typing were employed to analyze patients and their parents. Benign or likely benign variants of the AIRE gene were identified in all participants of the study. These variants, coupled with clinical data and the results of antibody studies to type I interferons, helped to exclude APS-1. Patients with APS-2, in contrast to patient with AAI, inherited distinct variants of unknown significance in the CLEC16A gene, which is associated with autoimmune diseases, including AAI. Various risk alleles in other genes associated with autoimmunity were identified in all patients. HLA typing of class II loci revealed alleles related to APS. Nevertheless, the frequencies of the haplotypes identified are substantial in the healthy Russian population. Immunological tests can detect antibody carriers and assess the risk of autoimmune disease development. In the future, to identify genetic predictors of autoimmune endocrinopathies, it is recommended to analyze the whole genome of patients and their relatives, examining clinically relevant variants in non-coding regions.

BACKGROUND: It is known that insulinoma in approximately 5% of cases is associated with multiple endocrine neoplasia type 1 syndrome (MEN1), in which the prognosis and management tactics of patients have been developed in detail. The diagnosis of MEN1 often does not require genetic confirmation, since the syndrome has a typical clinical picture. At the same time, a combination of this tumor with other hereditary syndromes is found in the literature, which are characterized by the presence of malignant neoplasms of various localizations, primary multiple lesions, hormonal and other disorders. Thus, it is relevant to search for the genetic causes that cause the development of insulinoma, in addition to MEN1.AIM: to evaluate the frequency of detection of genetic causes of the development of insulin-producing tumors of the pancreas, in addition to MEN1; to analyze the phenotypic characteristics of patients with such tumors.MATERIALS AND METHODS: Based on the analysis of literature for the period up to 2020, a panel has been developed that includes coding regions of 10 genes (MEN1, VHL, TSC1, TSC2, KRAS, YY1, CDKN2A, MLH1, ADCY1, CACNA2D2) involved in the development of insulinoma. In 32 patients diagnosed with insulinoma, verified by pathomorphological examination, with the absence of clinical and/or genetic data indicating MEN1 syndrome, a panel of genes was sequenced with subsequent analysis of the identified genetic variants and phenotypic data obtained from the medical records of patients. In one patient, an additional molecular genetic study of the «Endom» panel was performed, revealing genetic variants of coding regions of 377 genes associated with endocrine diseases.RESULTS: In 8 patients (25%, 95% CI (11%; 43%)), 9 variants of mutations were identified that were not classified as benign, at that two mutations in the TSC2 gene were detected in one patient. Frequencies of genetic variants: TSC2 — 13%, 95% CI (4%; 29%), MEN1 — 6% (1%; 21%), MLH1 — 3% (0%;16%), CDKN2A/P16INK4A — 3% (0%;16%). When comparing patients with the identified mutation, with the exception of benign (n=8), and patients without mutation or with a benign mutation (n=24), there were no differences in the Grade (degree of differentiation), Ki67 proliferation index, frequency of concomitant tumors, burdened history, multiple pancreatic lesions or recurrence of insulinoma, however, patients with germinal mutation were found at the level of statistical trend to be younger at the manifestation of insulinoma and to have bigger tumors. In a patient who underwent an additional molecular genetic study using the new «Endome» panel, previously undescribed gene variants (APC and KIF1B) associated with various sporadic tumors, including endocrine ones, were identified.CONCLUSION: A panel of 10 genes has been developed, mutations of which are associated with insulinoma. A relatively high incidence of genetically determined insulinoma was determined (25% of cases), in half of cases — against the background of tuberous sclerosis. We consider it relevant to evaluate the effectiveness of genetic testing for patients with insulinoma. We believe that, first of all, patients with a high risk of hereditary pathology should be examined: with the manifestation of the disease at a young age and with a large tumor. The identification of a genetic mutation will make it possible to determine the prognosis of the disease, optimize the monitoring algorithm in order to timely identify concomitant diseases-components of the hereditary syndrome, and conduct genetic counseling of the family.

BACKGROUND: Recent clinical descriptions have shown that in adult patients, the cause of nondiabetic hypoglycemia (NDH) may be various genetically determined disorders of glucose metabolism or insulin synthesis/bioavailability. In this connection, in adult patients with NDH of unclear genesis, it is important to conduct a genetic study in order to search for mutations in genes associated with congenital disorders of glucose metabolism (CDGM).AIM: To evaluate the effectiveness of genetic testing to exclude CDGM in adult patients with idiopathic NDH.MATERIALS AND METHODS: Based on the analysis of the literature, a targeted panel has been developed, including 30 genes, mutations in which are associated with the following groups of diseases: 1) congenital hyperinsulinism (KCNJ11, ABCC8, GLUD1, HADH, UCP2, HNF4A, HNF1A, GCK, INSR, SLC16A1); 2) glycogen storage diseases (AGL); 3) other carbohydrate metabolism disorders (ALDOB, FBP1); 4) glycosylation defects (PMM2, ALG3, PGM1, MPI); 4) defects in fatty acid oxidation (ACADM, ETFA, ETFB, ETFDH, FLAD1, SLC25A32, SLC52A1, SLC52A2, SLC52A3); 5) disorders of ketone body metabolism (CPT1A, CPT2, HMGCL); 6) mitochondrial disorders (DLD). Twenty nine patients (n=29: with idiopathic NDH n=17 and with insulinoma n=12) aged 19 to 66 years underwent a genetic study using this custom panel.RESULTS: As a result of the examination 12 genetic variants (all heterozygous) were identified in 8 patients with idiopathic NDH (47%, 95% CI (23%; 72%)), at that two mutations were detected in three patients: in the genes AGL and HMGCL; ACADM and FLAD1, respectively; and one patient had three mutations: one mutation in the ETFA gene and two mutations in the ABCC8 gene. Frequencies of genetic variants: AGL — 18%, 95% CI (4%; 43%), ETFA — 12% (1%; 36%), HMGCL — 6% (0%; 29%), ALDOB — 6% (0%; 29%), CPT1A — 6% (0%; 29%), ABCC8 — 6% (0%; 29%), ACADM — 6% (0%; 29%), FLAD1 — 6% (0%; 29%). 5 genetic variants (all heterozygous) were identified in 5 patients with insulinoma (42%, 95% ДИ (15%; 72%)). Frequencies of genetic variants: ABCC8 — 17%, 95% CI (2%; 48%), HNF1A — 8% (0%; 38%), ETFDH — 8% (0%; 38%), MPI — 8% (0%; 38%). We did not include benign variants in this analysis. At the same time, clinically significant variants were identified only in one patient from the group with idiopathic NDH (6%, 95% CI (0%; 29%)) in the ABCC8 gene and in one patient from the group with insulinoma (8%, 95% CI (0%; 38%)) in the same gene congenital hyperinsulinism (CHI).CONCLUSION: A panel of 30 genes has been developed, variants of which are associated with a CDGM. The results of our study confirm the possibility of detecting CDGM in adulthood, in particular CHI, and indicate the need for genetic testing, primarily in patients with idiopathic NDH.

BACKGROUND: Artificial hypoglycemia (ArH) is a decrease of blood glucose levels less than 3 mmol/l due to the deliberate use of hypoglycemic drugs by a patient outside of medical appointments. Timely diagnosis of this kind of hypoglycemia avoids unnecessary numerous examinations and hospitalizations. However, the detection of ArH still remains an extremely difficult task for both the healthcare facility and the attending physician. The foreign literature describes cases of successful detection of deliberate intake of oral hypoglycemic drugs (OHD) using high-performance liquid chromatography with tandem mass spectrometric detection (HPLC-MS/MS). Thus, it is relevant to develop and validate a method for determining OHD using HPLC-MS/MS.AIM: To optimize the diagnosis of ArH due to the use of OHD.MATERIALS AND METHODS: A total of 92 patients were examined. The development of the HPLC-MS/MS method for the detection of the studied OHD (sOHD; n=1-glibenclamide, n=1-gliquidone, n=1-gliclazide, n=1-glimepiride, n=1-glipizide, n=1-nateglinide and n=1-repaglinide) in the blood was carried out in a group of patients with diabetes mellitus type 2 (n=7) who received sOHD, and a group of conditionally healthy people who did not receive any medications (n= 7). To validate the method, the determination of sOHD substances was carried out on groups of patients with hyperinsulinemic nondiabetic hypoglycemia (NDH) of unknown origin (n=11) and with insulinoma (n=67).RESULTS: In the study of blood samples by HPLC-MS/MS in the group of patients with diabetes mellitus type 2, was confirmed in 100% of the cases the use of the drug that the patient received, in the group of conditionally healthy — sOHD were not detected. A false positive result was not obtained in any conditionally healthy and in any patient with insulinoma. ArH was diagnosed in 5 out of 11 patients in the group with hyperinsulinemic NDH of unknown origin, the method identified sOHD glibenclamide and gliclazide in the patients’ blood samples. In the remaining 6 patients of this group, examinations were continued and other causes of NDH were diagnosed. The sensitivity of the method was 100% [74%; 100%], specificity — 100% [95%; 100%].CONCLUSION: The HPLC-MS/MS method has high diagnostic accuracy in the detection and identification of sOHD (glibenclamide, gliquidone, gliclazide, glimepiride, glipizide, nateglinide and repaglinide) in blood samples of patients receiving these drugs. Currently, due to the low availability of the method, this study is advisable to use in patients with hyperinsulinemic hypoglycemia with negative results of first-line insulinoma imaging methods (computed tomography with contrast enhancement, ultrasound and magnetic resonance imaging of the abdominal cavity).

BACKGROUND: It is known that insulinoma in approximately 5% of cases is associated with multiple endocrine neoplasia type 1 syndrome (MEN1), in which the prognosis and management tactics of patients have been developed in detail. The diagnosis of MEN1 often does not require genetic confirmation, since the syndrome has a typical clinical picture. At the same time, a combination of this tumor with other hereditary syndromes is found in the literature, which are characterized by the presence of malignant neoplasms of various localizations, primary multiple lesions, hormonal and other disorders. Thus, it is relevant to search for the genetic causes that cause the development of insulinoma, in addition to MEN1.AIM: to evaluate the frequency of detection of genetic causes of the development of insulin-producing tumors of the pancreas, in addition to MEN1; to analyze the phenotypic characteristics of patients with such tumors.MATERIALS AND METHODS: Based on the analysis of literature for the period up to 2020, a panel has been developed that includes coding regions of 10 genes (MEN1, VHL, TSC1, TSC2, KRAS, YY1, CDKN2A, MLH1, ADCY1, CACNA2D2) involved in the development of insulinoma. In 32 patients diagnosed with insulinoma, verified by pathomorphological examination, with the absence of clinical and/or genetic data indicating MEN1 syndrome, a panel of genes was sequenced with subsequent analysis of the identified genetic variants and phenotypic data obtained from the medical records of patients. In one patient, an additional molecular genetic study of the «Endom» panel was performed, revealing genetic variants of coding regions of 377 genes associated with endocrine diseases.RESULTS: In 8 patients (25%, 95% CI (11%; 43%)), 9 variants of mutations were identified that were not classified as benign, at that two mutations in the TSC2 gene were detected in one patient. Frequencies of genetic variants: TSC2 — 13%, 95% CI (4%; 29%), MEN1 — 6% (1%; 21%), MLH1 — 3% (0%;16%), CDKN2A/P16INK4A — 3% (0%;16%). When comparing patients with the identified mutation, with the exception of benign (n=8), and patients without mutation or with a benign mutation (n=24), there were no differences in the Grade (degree of differentiation), Ki67 proliferation index, frequency of concomitant tumors, burdened history, multiple pancreatic lesions or recurrence of insulinoma, however, patients with germinal mutation were found at the level of statistical trend to be younger at the manifestation of insulinoma and to have bigger tumors. In a patient who underwent an additional molecular genetic study using the new «Endome» panel, previously undescribed gene variants (APC and KIF1B) associated with various sporadic tumors, including endocrine ones, were identified.CONCLUSION: A panel of 10 genes has been developed, mutations of which are associated with insulinoma. A relatively high incidence of genetically determined insulinoma was determined (25% of cases), in half of cases — against the background of tuberous sclerosis. We consider it relevant to evaluate the effectiveness of genetic testing for patients with insulinoma. We believe that, first of all, patients with a high risk of hereditary pathology should be examined: with the manifestation of the disease at a young age and with a large tumor. The identification of a genetic mutation will make it possible to determine the prognosis of the disease, optimize the monitoring algorithm in order to timely identify concomitant diseases-components of the hereditary syndrome, and conduct genetic counseling of the family.

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Autoantibodies (Abs) to thyroid antigens are associated with autoimmune thyroid disease (AITD), although sometimes they have no clear clinical significance. The aim of this study was to evaluate the avidity of thyroid Abs in the sera of AITD patients and non-AITD Abs carriers. A multiplex microarray-based assay was developed to detect the avidity of thyroid disease-associated Abs, including Abs to thyroperoxidase (TPO), thyroglobulin (Tg), pendrin, thyroid hormones T3 and T4, pyruvate kinase, and carbonic anhydrase 2. The method is based on indirect multiplex assay with an additional step involving the chaotrope destruction of the autoantibody-antigen complexes. The avidity index (AI) is then calculated. The method was tested on clinical cohort (n =117) and then confirmed by studies with another independent cohort (n =123). For the confirmation study, the median AI for AbTg was 29.9% among healthy Abs carriers, 52.6% for AITD patients, and 92.7% for non-AITD type 1 diabetes (T1D) patients. Median AI for AbTPO were 39.9% in healthy carriers, 73.4% in AITD patients, 83.2% in T1D patients, and 98.5% in AITD patients with thyroid neoplasm. The presence of high-avidity AbTg in T1D patients was also confirmed by a modified ELISA. Identification of high-avidity autoantibodies to thyroid proteins in non-thyroid T1D patients requires further studies.

Autoimmune polyglandular syndrome type 1 (APS 1) is a rare genetic disorder caused by a mutation in the autoimmune regulator AIRE gene. The diagnosis is usually based on the combination of at least two components of the classic triad: mucocutaneous candidiasis, hypoparathyroidism, and primary adrenal insufficiency. Other autoimmune disorders, including thyroid diseases, also occur and may manifest before the primary components. The disease is more likely to manifest during infancy, but some components may develop in adult patients. As the components of the syndrome do not occur simultaneously, verification of the diagnosis is often delayed. A significant challenge in the management of patients with APS 1 is the selection of optimal drug doses due to polypragmasy and the frequent presence of autoimmune disorders and/or candidiasis of the gastrointestinal tract. We present a clinical case of a patient with an atypical course of APS 1, in whom the first endocrine components (hypoparathyroidism and hypothyroidism) were diagnosed in adulthood. This case highlights the phenotypic diversity of APS 1, and the difficulties in selecting therapy when several autoimmune endocrine diseases are combined.