LEVELS OF N-TERMINAL TELOPEPTIDE OF COLLAGEN TYPE I IN MEN WITH ANKYLOSING SPONDYLITIS, CONNECTION WITH THE COURSE OF THE DISEASE

Shevchuk S.V.¹, Pavliuk O.M.², Korobko O.A.²

• ¹Scientific and research institute of invalid rehabilitation (educational scientific treatment complex) of National Pirogov Memorial Medical University
• ²National Pirogov Memorial Medical University, Vinnytsya

Summary. Over the last years, a large number of markers characterizing the degeneration of bone tissue were discovered which. One of the most informative markers of bone resorption is N-terminal telopeptide of collagen type I (NTx). As of today, there are no data on its level in case of ankylosing spondylitis (AS) and the role of clinical course in case of formation of disorders of levels of NTx remains practically unstudied. Study objective: to evaluate the levels of NTx in men suffering from AS and to establish their connection with structural and functional state of bone tissue and clinical course. Materials and methods: main group consisted of 83 men suffering from ankylosing spondylitis aged 40,7±0,8 years, average clinical course was equal to 8,7±0,5 years. Disease activity and the level of functional limitations was determined using BASDAI, ASDAS-CRP scores and BASFI functional index. A laboratory study included the determination of C-reactive protein (CRP) and the marker of bone resorption (NTx). Bone mineral density (BMD) was measured using double energy X-ray absorptiometry. Results: levels of NTx differed significantly in men suffering from AS and in persons of the control group. In the control group the level of resorption was 92,6±5,1 ng/ml, while in persons suffering from AS it was 1,2 times higher and made up 105,8±3,4 ng/ml. It was established that low bone mineral density is associated with an increased degeneration of bone tissue. Thus, in the group of persons with osteoporosis, high level of resorption marker was found in every second patient and the average level was 39% higher than in the group with a preserved BMD. It was also found that NTx levels are closely related to the activity of the inflammatory process and low functional capacity, which was confirmed by the obtained probable correlation between NTx concentration and the level of CRP (r = 0,3), ASDAS (r = 0,21) and BASDAI (r = 0,37), BASFI functional index (r = 0,25). Conclusions: 26,5% of men suffering from AS show a high level of bone resorption marker which is closely associated with low BMD, marked functional disorders (BASFI) and high activity (BASDAI, ASDAS, CRP) of inflammation process, has little relation to cumulative dose of GCs and no connection to the age of patients, disease duration and BMI.