synovial fluid in rheumatic disease

Last reviewed 01/2018

Synovial fluid in rheumatic disease may be assessed in terms of appearance, viscosity, white cell count, the presence of crystals, and the presence of organisms on culture.

Normal synovial fluid is clear and straw coloured. Depending on the type and amount of cells contained however, the fluid may appear blood stained or cloudy. In an inflammatory fluid the fluid tends to be more opaque due to the presence of an increased number of white cells.

Other specific tests on synovial fluid may reveal further information i.e.

  • low complement levels are associated with rheumatoid arthritis and Reiter's syndrome
  • in rheumatoid arthritis the levels of IgM and IgG are higher in the synovial fluid than in the serum