Synovial fluid analysis--another look at the mucin clot test.

We analyzed the relationship between the mucin clot test and the synovial fluid (SF) leukocyte count in osteoarthritis, rheumatoid arthritis (RA), gout, and calcium pyrophosphate dihydrate crystal deposition disease. Except for RA there was no statistically significant relationship between white count and a tight mucin determination within the disease categories. For low (2 X 10(9) cells/l or less) leukocyte counts, the crystal induced arthropathies had a significantly greater proportion showing a tight reaction than found in the osteoarthritic and rheumatoid fluids. We propose that mucin clot determinations may reflect synovial membrane activity rather than SF leukocyte counts.