POS0169 FETUIN-A AS A MARKER OF OSTEOPOROSIS AND OSTEOPOROTIC FRACTURES IN PATIENTS WITH RHEUMATOID ARTHRITIS
Authors: Y. Akhverdyan, E. Papichev, В. Zavodovsky, L. Seewordova, J. Polyakova
Journal: Annals of the Rheumatic Diseases (2021)

Background: The main mechanism of the effect of fetuin-A (FeA) on bone metabolism is its ability to bind calcium and proteins of the TGF-β family. It has been proven that the optimal concentration of TGF-β is necessary for the differentiation of bone tissue, and a high concentration inhibits bone mineralization. Thus, adequate osteogenesis is based on a complex balance between FeA and TGF-β levels. It can be assumed that the determination of the FeA level in the blood of patients with rheumatoid arthritis (RA) will help to optimize the diagnosis and predict the severity of osteoporosis (OP). Objectives: to study the possibility of predicting the development of osteoporosis and osteoporetic fractures in patients with RA, depending on the level of FeA in blood serum. Methods: We examined two groups of patients (52 patients with RA complicated by OP, 58 patients with RA without OP) and 30 apparently healthy individuals. The age of the surveyed ranged from 18 to 72 years, the average duration of the disease was 7.53±0.89 years. In both groups, the FeA level was determined by an indirect enzyme-linked immunosorbent assay using a commercial test. Bone mineral density (BMD) was also measured in both groups (Lunar DPX-NT GE). Results: The average FeA level in the group of RA patients was lower than in the group of conventionally healthy individuals (731.21±109.9 μg/ml and 812.9±76.2 μg/ml, respectively; F=13.34; p=0,0004). The normal FeA level was calculated using the formula M±2σ in the group of apparently healthy individuals and ranged from 653.55 μg/ml to 972.19 μg/ml. A decreased level of FeA was found in 20 patients (86.96%) in the group of patients with OP and only in 3 (13.04%) patients with RA who did not suffer from OP (p&lt;0.001). It can be concluded that patients with RA and a low concentration of FeA in the blood serum have a higher risk of developing OP. In the group of patients with normal FeA level, osteoporetic fractures were observed in 12 (13.79%) patients and were absent in 75 (86.21%) patients (p&lt;0.001). Thus, RA patients with normal serum FeA levels have a lower risk of osteoporetic fractures. We also found a positive significant correlation between the level of FeA and BMD in the femoral neck area. In the group of patients with a reduced FeA level (23 people), the mean BMD values were 0.732±0.022 g/cm2, and in the group of patients with a normal FeA level (87 patients) - 0.890±0.014 g/cm2 (p&lt;0.001, F=27.663). The obtained values are in agreement with the literature data on the effect of the serum FeA concentration on the BMD values. Conclusion: We consider it expedient to determine the serum FeA concentration in patients with RA. At a FeA level of 653.55 μg/ml and below, a higher risk of developing OP and osteoporetic fractures can be predicted. In this case, the patient is shown a standard examination for osteoporosis. At values of 653.55 μg/ml and above, a more expectant management of the patient is allowed. Thus, by determining the serum concentration of FeA, it is possible to implement an integrated approach to the patient and to optimize the schemes for the diagnosis of OP in patients with RA. Disclosure of Interests: None declared