AB1001 CHANGES IN THE PARATHYROID HORMONE LEVEL IN CHILDREN WITH JUVENILE IDIOPATHIC ARTHRITIS

Abstract

Background: It is proved that rheumatic diseases are accompanied by pronounced changes in calcium-phosphorus metabolism, which underlies the development of osteopenia syndrome. If in previous years glucocorticosteroid therapy (GCS) was considered to be the main reason for this, then the role of pro-inflammatory agents (activity of the pathological process), provision with vitamin D (VitD), and the effect of basic therapy are currently being discussed. It is also known that a decrease blood level of vitamin D leads to a violation of the absorption of calcium and phosphorus, a further increase in the level of parathyroid hormone, which underlies the risk of a decrease in bone mineral density. Objective(s): To study the level of parathyroid hormone in children with juvenile idiopathic arthritis, its relationship with the course of the disease and vitamin D status. Method(s): 91 patients with JIA (61 girls and 30 boys), with polyarticular (n = 41), oligoarticular (n = 29) and undifferentiated (n = 18) variants of JIA were examined. The age of the patients was 10.5 +/- 1.7 years. The duration of the disease was 4.1 +/- 1.1 years. All children receive basic methotrexate therapy. The control group included 25 peers of the corresponding gender. JADAS27 was counted, the levels of 25-hydroxycalciferol (25-OH D) and PTH were determined by chemiluminescent method. Corresponded to the content of vitamin D in blood serum, the normal level was noted in 14 patients, insufficiency-in 41 patients, deficiency-in 32 patients. Result(s): The level of PTH in children with JIA remained within physiological values (30.6 +/- 2.1 pg/ml; from 12.7 to 61.8 pg/ml) despite the high frequency of a VitD decrease in blood (80.2%). The level of PTH was not significant in groups of patients with a different level of vitamin D (32.8 +/- 2.1 pg/ml at deficiency group; 29.2 +/- 2.4 pg/ml at insufficiency group; 29.1 +/- 1.8 pg/ml at a normal level of VitD group). PTH was comparable and did not differ in children of different sexes. The highest level of PTH was in patients with a polyarticular variant of JIA (34.2 +/- 4.5 pg / ml, p<0.05), which was accompanied by the lowest level of vitamin D (20.9 +/- 2.1 ng / ml, p <0, 05) in the same group. There was obtained reliable correlations of activity indicators (JADAS27) taking into account Vit D and PTH, as well as with diseases duration and age of patients (p <0.05). Conclusion(s): A study of the level of PTH in children with JIA did not show a significant increase depending on the vitamin D status in these patients. However, the age-related state of PTH is associated with the activity of the pathological process, the prevalence of articular syndrome and prolonged illness.