What is the ESR blood test 1

Erythrocyte sedimentation rate

Synonyms: sedimentation, sedimentation rate, sedimentation rate, ESR, ESR, BKS, BSR
English: sedimentation rate, sed rate

1 definition

The Erythrocyte sedimentation rate, short ESR, is a frequently used search test for suspected inflammatory diseases that is relatively unspecific. The ESR can also provide information on the assessment of the course of inflammatory diseases.

Another term that is frequently used for ESR is the term "erythrocyte sedimentation rate", for short BSG.

2 background

The ESR is mainly influenced by the composition of the plasma proteins. The negative charge of the erythrocytes causes them to repel each other and sedimentation takes place only slowly. Plasma proteins, which partially neutralize the negative charge of the erythrocytes (reduction of the zeta potential), lead to faster agglomeration of the erythrocytes and thus to a more rapid decrease in the blood cells. These proteins are therefore also grouped together as agglomerins. These include above all acute phase proteins (e.g. fibrinogen), which are released during inflammatory reactions. The negatively charged albumin reduces the ESR.

3 method

The erythrocyte sedimentation rate can be determined according to Westergren. 0.4 ml of a 3.8% sodium citrate solution is mixed with 1.6 ml of venous blood. As a rule, the blood is transferred directly to special vessels (e.g. Monovettes®) that already contain the citrate solution. This gives what is known as citrated blood.

The blood is then filled into a vertical pipette 200 mm high and graduated in millimeters. After 1 hour, the lowering of the red erythrocyte column is read off in mm. As a rule, the 2-hour value does not provide any significant additional information. The reading can be done visually or by machines.

Since the classic citrate method is time-critical, EDTA blood is also used for ESR in laboratory medicine. In paediatrics, controls are often carried out in capillary tubes as a so-called microsink.

4 reference range

Maximum physiological value after 1 hour:

4.1 People under 50 years of age

  • Men: 3 to 15 mm (according to some sources also 10 mm)
  • Females: 6 to 20 mm

4.2 People over 50 years of age

  • Males: 3 to 20 mm
  • Females: 6 to 30 mm

An extremely high ESR is referred to as a fall reduction.

5 Meaningfulness

The test is sensitive but does not provide any information about the underlying causes of the increase in ESR. The value correlates within certain limits with the activity of the inflammation. In the elderly, as well as in women premenstrually and during pregnancy, it can be physiologically increased. The value is influenced by various factors. This includes, for example, a changed body temperature or the use of medication (e.g. isotretinoin or ovulation inhibitors). The value can be changed for a large number of diseases.

6 interpretation

6.1 Increased ESR

6.2 Decreased ESR

7 Notice

The diagnostic value of the C-reactive protein (CRP) is comparable to the ESR, but has the following advantages:

  • not influenced by erythrocyte factors
  • faster decline after inflammation subsides

8 literature

  • Laborlexikon.de; accessed on 02/09/2021