Serum hyaluronic acid as a potential marker with a predictive value for further radiographic progression of hand osteoarthritis.

Objective: To compare serum levels of hyaluronic acid (HA) between patients with erosive and non-erosive hand osteoarthritis (HOA), and investigate its association with morphological changes and radiographic progression over 2 years.

Methods: Fifty-five women with erosive and 33 women with non-erosive HOA were included in this study. All underwent clinical examination, which included assessment of pain, swelling, deformity and deviation of small hand joints and completed health assessment questionnaires. Serum levels of HA were measured by ELISA. Three-phase bone scintigraphy was performed at baseline. Radiographs of both hands were performed at baseline and after 2 years and scored according Kallman grading scale.

Results: Serum levels of HA were significantly higher in patients with erosive than with non-erosive HOA (P<0.01). It correlated significantly with the number of hand joints with deviations and deformities. HA adjusted for age and disease duration significantly correlated with radiographs at baseline and after 2 years in all patients with HOA (r=0.560 and r=0.542, P<0.01 for both correlations). Although there was an association between HA and radiographic score in erosive disease, after adjustment for confounders it remained no longer significant. HA adjusted for confounders correlated significantly with the late phase in all patients with HOA (r=0.412, P<0.01) and in patients with erosive disease (r=0.320, P<0.05).

Conclusion: HA is increased in patients with erosive HOA and could be proposed as a surrogate marker with a predictive value for further radiographic progression of HOA in general. Further investigation is necessary to confirm these results.