AB0160 THE RELATIONSHIP BETWEEN THE LEVEL OF FETUIN-A AND LABORATORY MARKERS OF CONNECTIVE TISSUE DESTRUCTION IN PATIENTS WITH RHEUMATOID ARTHRITIS

Abstract

BackgroundIt is known that there are biochemical markers of cartilage and bone tissue destruction, which reflect the metabolic processes occurring in tissues. For example, in rheumatoid arthritis (RA), routine markers such as CTX-I, a bone degradation marker (C-terminal telopeptide of type I collagen) and CTX-II, a cartilage degradation marker (C-terminal telopeptide of type II collagen), can be used. Also, to assess the state of cartilage tissue, the determination of type II collagen fragments by Urine CartiLaps is widely used, which allows not only primary diagnosis, but also dynamic monitoring of metabolic processes.ObjectivesThe aim of our research was to study the relationship between the level of fetuin-A (FeA) and laboratory markers of bone and cartilage tissue degradation in the blood serum of patients with RA.MethodsWe observed 110 patients with a verified diagnosis of RA, the control group consisted of 30 practically healthy individuals without joint diseases. The group of patients with RA and the control group were comparable in terms of age (p=0.083), gender (p=0.116), BMI (p=0.302). The diagnosis of RA was based on the clinical classification adopted at the EULAR/ACR in 2010. The level of FeA in the blood serum was determined once by enzyme immunoassay using commercial test systems (Human Fetuin-A ELISA Biovender Cat No. 191-0371).ResultsWe have assessed the FeA level in the group of RA patients and healthy donors. The normal level of FA in healthy individuals, calculated as M±2σ, ranged from 653.55 µg/ml to 972.19 µg/ml. FeA level was normally distributed (K-S d=0.062, p>0.2). We also studied the relationship between indicators of bone metabolism and the concentration of FeA. In patients with normal FeA levels (n=87), the mean CTX-1 level was 35 ng/mL; in patients with reduced FeA levels (n=23), the mean CTX-1 level was 51 ng/ml (t=-2.42 p =0.016). Thus, with a decrease in the FeA level, CTX-I (an indicator of osteodestruction) tended to increase.Next, we analyzed the relationship between low and normal levels of FeA and the Cartilaps/urine creatinine ratio using intragroup analysis methods. In the group with low FeA level Cartilaps/urinary creatinine was 598.9±223.72 µg/mmol versus 481.17±226.93 µg/mmol in the group with normal FeA level (Z=-2.311; p=0.021). Our data probably allow us to associate the FeA level with the rate of cartilage tissue destruction.ConclusionConsidering that the levels of laboratory markers of cartilage and bone collagen degradation Cartilaps and CTX-I were statistically lower in the presence of an elevated serum level of FeA, we can conclude that FeA has chondro- and osteoprotective properties. It can also be assumed that the level of this marker can be used to predict the rate of cartilage destruction in patients with RA, but this issue requires further study.Disclosure of InterestsNone declared