The discovery of the erythrocyte sedimentation rate (ESR) was made by Polish physician Edmund Faustyn Biernacki. In 1897, he demonstrated the value of the test in establishing a diagnosis to the Warsaw Medical Society.¹ The practical applications of the ESR test was not well known until the work of Robert Fahraeus and Alf Westergren in 1921.^1,2 Together, Fahraeus and Westergren are remembered for the test, historically called the Fahraeus-Westergren test (FW test or Westergren test), which uses a standardized tube and sodium citrate anticoagulated blood.²

The Westergren method for measuring ESR proposed by the International Committee for Standardization in Haematology (ICSH) has allowed reproducibility now for almost a century.² The erythrocyte sedimentation rate (ESR) continues to be a widely used test, serving as an indicator of inflammation and performed routinely to monitor patients of autoimmune and infectious diseases.³ Automated ESR tests that utilize a form of syllectometry, or the direct measure of red blood cell aggregation, are now available and in high-volume laboratories where manual measurement may be tedious. This method of ESR measurement, photometric rheology, has been shown to safely replace the Westergren method for low-ESR values in patients with low hematocrit.³ For high-ESR values, validation by the standard Westergren method may be needed.³ The Clinical and Laboratory Standards Institute (CLSI) has addressed the need for a unifying standard, Procedures for the Erythrocyte Sedimentation Rate Test; Approved Standard—Fifth Edition (H02-A5) to offer comparability of results for new technologies to those of previous methods.^4,5

Photometric rheology offers improved operator safety and reduced ESR analysis time. It has shown analytical validity when compared to Westergren and other types of ESR analysis.⁶ The method is fully automated and results can be produced in 20 seconds. The test is deemed moderately complex at this time.⁷

Laboratory professionals are well versed with the ESR. Many are unaware of the physics, clinical utility, or modern technologies which allow for more efficient measurements.