What is the definition of erythrocyte sedimentation rate

ESR (erythrocyte sedimentation rate) refers to the rate at which red blood cells naturally settle in plasma under certain conditions, and is a commonly used non-specific inflammatory indicator in clinical practice. The test results are mainly influenced by plasma protein composition, red blood cell count and morphology, temperature, and technical factors, and are commonly used to assist in the diagnosis of pathological conditions such as infections, rheumatic and immune diseases, tumors, etc.

1. Detection principle:

Red blood cell sedimentation is based on Stokes' law. When there is an increase in large molecular proteins such as fibrinogen and immunoglobulin in the plasma, it will reduce the negative charge repulsion on the surface of red blood cells, promote the formation of a coin shaped aggregation of red blood cells, and accelerate sedimentation. After vertically standing anticoagulated whole blood for 1 hour, the ESR value is obtained by reading the height of the plasma layer.

2. Influencing factors:

physiological elevation is seen during pregnancy, menstruation, and the elderly; Pathological increase is common in inflammatory diseases such as bacterial infection, tuberculosis and rheumatoid arthritis, malignant tumors such as multiple myeloma, and non inflammatory conditions such as anemia and tissue necrosis. Technical factors such as the placement time after blood collection and the inclination of the test tube can also interfere with the results.

3. Clinical significance: As a non-specific indicator, elevated ESR suggests the presence of pathological processes in the body but cannot determine specific diseases. Dynamic monitoring can be used to evaluate the activity of inflammation, such as a decrease in ESR during the treatment of wind dampness heat indicating disease relief. It is necessary to make a comprehensive judgment based on specific indicators such as C-reactive protein and clinical manifestations.

4. Reference range:

Wei's method for adult males 0-15mm/h and females 0-20mm/h. Children and newborns have a lower speed, reaching up to 40mm/h in late pregnancy. Different detection methods, such as automated instrument methods, require corresponding standards, and the laboratory should indicate the specific detection system.

5. Limitations:

ESR cannot distinguish between infectious and non infectious inflammation, and about 5% of patients with active inflammation may have normal ESR. In severe anemia, accelerated sedimentation may mask the true degree of inflammation, while conditions such as polycythemia and sickle cell anemia can lead to a false decrease. It cannot be used alone as a diagnostic basis.

It is recommended to maintain the same testing conditions when regularly monitoring red blood cell sedimentation rate, and avoid blood collection after intense exercise or high-fat diet. Continuous abnormal elevation requires improvement in immune fixation electrophoresis, serum protein electrophoresis, and other examinations to investigate the cause. Mild elevation in the elderly population can be observed if there are no symptoms, and combined with comprehensive evaluation of blood routine, CRP and other indicators. Before testing, avoid using drugs such as aspirin that may affect the results, and the laboratory should standardize operations to reduce technical errors.