Normal erythrocyte sedimentation rate with hyperfibrinogenemia in 6-sulfanilamidoindazole arthritis

The erythrocyte sedimentation rate (ESR) is the most frequently employed laboratory indicator of inflammatory activity. The plasma fibrinogen concentration is usually increased in inflammatory disorders and is thought to contribute to the ESR elevation, 6-sulfanilamidoindazole induced arthritis in rats produces very high plasma fibrinogen concentrations and increased blood viscosity but no change in ESR.