Osteoprotegerin in rheumatoid arthritis

Abstract EN

Objective : to evaluate serum and synovial fluid levels of osteoprotegerin (OPG) in patients with rheumatoid arthritis (RA); to correlate these values with disease activity variables, radiological bone damage, and DEXA results.

Methodology : Twenty female RA patients and ten age-matched healthy female subjects were enrolled in this study.

Serum and synovial fluid OPG levels were measured using enzyme-linked immunosorbent assay.

Bone status was evaluated using dual x-ray absorptiometry (DEXA) and plain X-ray of the affected joints.

Results : RA patients had significantly higher levels of serum OPG than controls (p < 0.001).

No significant correlation was found between serum OPG and erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor and disease duration (p > 0.05).

OPG serum levels were positively correlated with age in both groups (p < 0.001).

A significant difference in serum OPG level was found between patients with and without erosions (p = 0.008).

RA patients had significantly lower BMD values than controls (p < 0.05).

There was a highly significant correlation between serum OPG level and BMD values (p < 0.001).

Mean synovial fluid OPG level was higher than serum OPG level obtained from the same patient, but with no statistical significance (p > 0.05).

Conclusion : bone loss in RA patients is associated with higher serum and synovial fluid levels of OPG than in healthy subjects, which might be the result of a compensatory production of OPG, yet there was lack of compensatory age-related increase of OPG serum levels.