MEASUREMENT OF COLONY-STIMULATING FACTORS IN SYNOVIAL-FLUID - POTENTIAL CLINICAL-VALUE

In this study, 100 synovial fluid (SF) samples from patients with a va riety of arthritides were assayed for levels of colony-stimulating fac tors (CSFs) using a human bone-marrow bioassay and enzyme immunoassays for granulocyte (G-) and granulocyte-macrophage (GM-)CSFs. GM-CSF was found more frequently in samples from rheumatoid arthritis (RA) subje cts (49%) than in non-RA samples (29%). Absence of GM- but not G- or b ioassay CSFs characterised samples from subjects with psoriatic arthri tis and ankylosing spondylitis (n=14). There was strong evidence of an antagonistic relationship between levels of G- and GM-CSFs in samples from RA patients, an effect independent of drug treatment. However, t reatment with nonsteroidal anti-inflammatory agents (NSAIDs) may affec t reported CSF concentrations: G-CSF levers were significantly lower i n samples from subjects not taking NSAIDs. These results suggest that SF-CSF estimations using commercially available assays could provide u seful diagnostic clues for clinicians, but careful interpretation is w arranted particularly in patients on long-term NSAID treatment.