Plasma viscosity and erythrocyte sedimentation rate in inflammatory and non-inflammatory rheumatic disorders.

Plasma viscosity (PV) and erythrocyte sedimentation rate (ESR) are considered to reflect the complex of acute phase reactants in inflammations. Both tests were studied with regard to their ability to discriminate between inflammatory and non-inflammatory rheumatic diseases. PV and ESR were measured using the Coulter Viscometer II and the Westergren method, respectively. ESR was found to be a better parameter for rheumatoid arthritis and ankylosing spondylitis than PV, independent of the chosen reference values, age, gender and the hemoglobin level. ESR may still be regarded as an acceptable parameter for monitoring inflammatory rheumatic diseases.