Erythrocyte Sedimentation Rate

Excerpt

The erythrocyte sedimentation rate (sedimentation rate, sed rate, or ESR for short) is a commonly performed hematology test that may indicate and monitor an increase in inflammatory activity within the body caused by one or more conditions such as autoimmune disease, infections, or tumors. The ESR is not specific for any single disease but is used in combination with other tests to determine the presence of increased inflammatory activity. The ESR has long been used as a "sickness indicator" due to its reproducibility and low cost. Over many decades, several methods have evolved to perform the test. However, the reference method for measuring the ESR proposed by the International Committee for Standardization in Haematology (ICSH) is based on the findings described by Westergren a century ago. Newer automated systems using closed blood collection tubes and automatic readers have been introduced into laboratories to decrease the biohazardous risk to operators and decrease the time it takes to perform the ESR.

The Westergren method measures the distance (in millimeters) at which red blood cells in anticoagulated whole blood fall to the bottom of a standardized, upright, elongated tube over one hour due to the influence of gravity. The tube used for the test is called the Westergren tube. Today, these tubes are made of either glass or plastic, with an internal diameter of 2.5 mm and lengths of 190 to 300 mm.

Perhaps the first to notice a change in blood sedimentation due to illness was a British surgeon John Hunter (1728–93), in his posthumous publication, A Treatise on the Blood, Inflammation, and Gun-Shot Wounds. A Polish physician, Edmund Faustyn Biernacki (1866–1911), later refined the clinical use of the ESR near the end of the 19th century. Biernacki detailed his findings in two articles in 1897 (the Gazeta Lekarska in Poland and the Deutsche Medizinische Wochenschrift in Germany) and developed his test for measurements. These findings were not widely propagated in the English-speaking medical communities. Because of his work, the ESR is occasionally called the Biernacki Reaction worldwide.

The applied use of ESR in clinical diagnostics by Biernacki was refined by Dr. Robert Fahraeus in 1918 and Dr. Alf Vilhelm Albertsson Westergren in 1921. Dr. Westergren defined the standard measurement of the ESR that is still in use today. Together, Robert Fahraeus and Alf Vilhelm Albertsson Westergren are often 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.

The Westergren method for measuring the ESR proposed by the International Committee for Standardization in Haematology (ICSH) has allowed reproducibility for almost a century. Over time, this same method has established comparable reference values within the same laboratory and even between different facilities across the globe. The ICSH adopted the Westergren method as the gold standard for ESR measurement in 1973. Even after the advent of automated machines used to analyze the ESR, the Westergren method was still confirmed as the gold standard in 2011 by both the ICSH and the Clinical and Laboratory Standards Institute (CLSI).