To evaluate serum levels of hyaluronic acid (HA) in patients with fibromyalgia (FM).
HA serum levels were evaluated by a radiometric assay in 42 women with FM (ACR criteria), 27 female patients with rheumatoid arthritis (RA) and 36 healthy female controls matched for age.
HA serum levels (mean microg/l +/- SEM) were 41 +/- 8.7 in healthy controls; 113 +/- 15.9 in RA: and 420 +/- 26 in FM.
HA serum levels in women with FM were significantly elevated compared to healthy controls and patients with RA. This observation suggests that FM is associated with a biochemical abnormality and that serum HA could be a laboratory marker for its diagnosis.