[The role of calcium sensitive and vitamin D receptors in the pathogenesis of sporadic multiple parathyroid gland disease].

BACKGROUND: Sporadic multiple parathyroid gland disease is » cases of primary hyperparathyroidism (PHPT). However, a single tactic for diagnosing and operating volume in patients with this variant of PHPT has not yet been developed. One of the possible directions in the search for pathogenetically substantiated methods of diagnosis and treatment is the study of the molecular genetic features of the disease and associated clinical and laboratory factors. AIM: To study the features of the expression of calcium sensitive (CaSR) and vitamin D (VDR) receptors on the surface of parathyroid cells in primary hyperparathyroidism with solitary and multiple lesions of the parathyroid glands, as well as its changes under the influence of a decrease in the filtration function of the kidneys. MATERIALS AND METHODS: In a single center observational prospective study with retrospective data collection, there were patients who during 2019-2021. operated on for PHPT, secondary hyperparathyroidism (SHPT) and all cases of tertiary hyperparathyroidism (THPT) operated during 2014-2021. The expression of CaSR, VDR and its relationship with the main laboratory parameters, the clinical variant of hyperparathyroidism, and the morphological substrate were studied. RESULTS: The study included 69 patients: 19 with multiple and 25 with solitary PTG near PHPT, 15 with SHPT, 10 with THPT. A statistically significant decrease in the frequency of detection of normal expression of CaSR and VDR receptors occurs in any morphological variant of hyperparathyroidism and is observed in 93-60% of drugs. A decrease in the normal expression of CaSR in hyperplasia is detected statistically significantly less frequently than in adenoma (p≤0.01). The median expression intensity in adenoma was 2.5 (2:3), in hyperplasia 3.5 (3-4) (p≤0.01). The difference in the molecular mechanisms of the development of hyperparathyroidism with a predominance of a morphological substrate in the form of adenoma (PHPT with solitary adenoma) or hyperplasia (SHPT and PHPT with multiple PTG lesions) is realized in the frequency of maintaining normal CaSR expression in the PTG tissue. These mechanisms are implemented at the local level, their variability does not change under the influence of RRT. A common molecular genetic mechanism for the development of hyperparathyroidism with a predominance of a morphological substrate in the form of adenoma or hyperplasia has been found to reduce the frequency of maintaining normal VDR expression in PTG (up to 7-13%), p<0.01. This mechanism is implemented at the local level, its variability changes under the influence of RRT, reaching statistically significant differences in patients with THPT. CONCLUSION: The study demonstrates the features of changes in the expression of CaSR and VDR in PHPT with multiple lesions of the parathyroid glands. The relationship between the expression of these receptors and the clinical variant of hyperparathyroidism, the morphological substrate, the main laboratory parameters, and renal function was shown.

[The case of late diagnosis of giant parathyroid adenoma in combination with fibrocystic osteitis and brown tumor of the upper jaw: a case report].

In this case report the authors inform about late diagnosis of giant adenoma of the parathyroid gland with primary hyperparathyroidism (PHPT) and the development of fibrocystic osteitis with a «brown¼ tumor of the upper jaw. The patient has been under the care endocrinologist with type 2 diabetes mellitus and multinodular goiter for 8 years.The last 5 years there was a clinical manifestation of PHPT, but the diagnosis was made by an oncologist after the detection of a «brown¼ tumor of the upper jaw. According to multispiral computed tomography and scintigraphy with 99mTc-MIBI, a focal lesion was found in the upper jaw on the right, lytic foci in the bones of the cranial vault, pelvis, lower extremities, ribs on the right, as well as a giant parathyroid adenoma on the right. According to the increased risk of the patient having a malignant neoplasm of the parathyroid gland, an extended surgical treatment of PHPT in the enblock volume was carried out with the achievement of remission of the PHPT. This clinical case illustrates a variant of the severe course of PHPT with the development of such a rare complication as fibrocystic osteitis and demonstrates the importance of timely diagnosis.