Bone Abstracts

The main cause of the bone destruction in rheumatoid arthritis (RA) is a destructive act of aggressively growing pannus, growth and angiogenesis of which are caused by the proliferation of fibroblasts in the synovium (S) due to the activation of fibroblast growth factor (FGF).

Objectives: To reveal relationships of FGF with ultrasonic and arthroscopic and proliferative-destructive histological figures in RA.

Methods: Complete comprehensive clinical laboratory and instrumental examination was performed in 128 patients with RA (ACR/EULAR 2010), the concentration of FGF in the blood was determined by enzyme immunoassay. Ultrasound of the knee joint was performed on the device ‘ESAOTE MyLAB40’, knee arthroscopy was performed using the arthroscope (Karl Storz GmbH), the biopsy of S was taken from the three most changed areas, samples were fixed in 10% buffered formalin, stained with hematoxylin and eosin, used the microscope Axiostar (Carl Zeiss).

Results: There were direct correlations the FGF with ultrasonic characteristic of the S thickness, with the presence of pannus and cartilage-bone erosions (P<0.001 in all cases). There was also a direct relation with the S vascularization intensity index (R=0.31, P=0.03). Indicator FGF had direct correlations with indicators of S macro-asssessment: arthroscopic – villous hyperplasia and the presence of pannus (P<0.001); and also with the parameters of S micro-assessment: histological – hyperplasia of the villi with the covering cell proliferation (P<0.01), mucoid swelling and fibrinoid changes (P<0.05).

Conclusion: The high concentration of FGF in the blood is related to the worsening of proliferative and destructive indices in RA, namely the degree of vascularization and thickening of S, pannus and cartilage-bone erosions formation. There for high FGF level in the blood of RA patients may be regarded as a marker of the early development of bone destruction.