PTX3 and rheumatoid arthritis: Elevated serum PTX3 expression has been observed in patients suffering from several arthritic conditions, including rheumatoid arthritis (2.08 ± 0.99 ng/ml), psoriatic arthritis (1.79 ± 0.80 ng/ml), polymyalgia rheumatic (2.08 ± 0.95 ng/ml), ankylosing spondylitis (2.48 ± 1.07 ng/ml) as well as other diseases such as giant cell arteritis (1.98 ± 1.05 ng/ml) and systemic lupus erythematosus (1.03 ± 0.84 ng/ml) [42].