[Novel hepatokine in rheumatoid arthritis laboratory diagnostics.]

Fetuin-A (α2-Heremans-Schmid glycoprotein, AHSG) is a glycoprotein mainly secreted by hepar in adults. It was shown, that AHSG is a positive as well as a negative acute-phase protein with pro- and anti-inflammatory effects. We studied serum levels of an AHSG in patients with rheumatoid arthritis (RA) and healthy controls in order to determine its role in the diagnostics of this disease. We measured serum levels of AHSG in 110 patients with RA and 30 healthy controls. To determine RA phenotype we measured rheumatoid factor and anticitrullinated protein antibodies. All patients were examined by the rheumatologist to identify clinical features of RA. Serum CRP and ESR were measured to assess inflammation. Mean level of AHSG in group with RA was 765,67±120,66 (Hereinafter M±σ), which was significantly lower than of healthy controls (812,76,2±76,2 μg/ml; p=0,0437). Insignificant difference of mean levels of AHSG was observed between men and women with RA (p=0,424). The reference ranges for AHSG measured from the healty controls were 653,55-972,19 ug/ml (M±2σ). We studied mean levels of AHSG according to the clinical and immunological manifestations of RA. AHSG levels were significantly lower within patients positive on ACCP, with moderate or high disease activity, with 2nd, 3rd and 4th x-ray stages and functional classes, with erosivity, extra-articular manifestations and complications. The moderate negative correlation was observed between AHSG level and CRP (r=-0,3146; p<0,001), ESR (r=-0,344; p<0,001) and DAS28 (r=-0,4334; p<0,001). In summary, AHSG mean levels were significantly different in patients with RA. It can be used to improve the diagnostics of RA activity, severity, extra-articular manifestations and complications.