The erythrocyte sedimentation rate (ESR), also called a sedimentation rate or Biernacki Reaction, [The test was invented by the Polish doctor Edmund Biernacki] is a common test in hematology [A branch of pathology dealing in blood investigations] and measures the rate at which red blood cells sediment in a period of 1 hour.
The erythrocyte sedimentation rate (is a nonspecific because increased results do not tell the doctor exactly where the inflammation is in the body or what is causing it, and also because it can be affected by other conditions besides inflammation.
For this reason, the ESR is typically used in conjunction with other tests.
For performing the test, anticoagulated blood is placed in an upright tube, known as a Westergren tube, and the rate at which the red blood cells fall is measured and reported in mm/h.
Classically, the test is performed by two methods
Since the introduction of automated analyzers into the clinical laboratory, the ESR test is automatically performed.
The sedimentation rate of blood cells depends on the balance between pro-sedimentation factors, mainly fibrinogen, and the factors resisting sedimentation, namely the negative charge of the erythrocytes.
An inflammation causes increase in proportion of fibrinogen in the blood causes which results in red blood cells sticking to each other to form stacks called ‘rouleaux,’ which settle faster and thus resulting in higher ESR.
Rouleaux formation can also occur in association with some lymphoproliferative disorders in which one or more immunoglobulin are secreted in high amounts.
The basal ESR is slightly higher in females.
The ESR is increased by any cause or focus of inflammation. The ESR is increased in pregnancy and anemia.
- Congestive heart failure
- Hypofibrinogenemia (decreased fibrinogen levels)
- Low plasma protein (due to liver or kidney disease)
- Sickle cell anemia
- Hereditary spherocytosis
ESR has limited role in limited use as a screening test in asymptomatic patients as the test itself has low sensitivity and specificity. Because the value rises in many conditions, the diagnostic ability of the test is of limited value. The test is more of suggestive value than diagnostic and the value is judged in correlation to symptoms and other parameters. If the ESR and clinical findings match, the doctor may be able to confirm or rule out a suspected diagnosis.
A single elevated ESR, without any symptoms of a specific disease, will usually not give the physician enough information to make a medical decision.Furthermore, a normal result does not rule out inflammation or disease.
Thus it is of some value in determining sickness in case of suspicion of the disease.
However, a very high value of ESR has some diagnostic significance in conditions like such as multiple myeloma, temporal arteritis, polymyalgia rheumatica, various auto-immune diseases, systemic lupus erythematosus, rheumatoid arthritis, and chronic kidney diseases, where it may exceed 100 mm/hour.
Also, ESR is frequently for a differential diagnosis of Kawasaki’s disease and is often increased in some chronic infective conditions like tuberculosis and infective endocarditis.
ESR is also a component of the Pediatric Crohn Disease Activity Index (PCDAI), an index for assessment of severity of inflammatory bowel disease in children.
ESR is helpful in diagnosing and monitoring therapy in temporal arteritis and polymyalgia rheumatica. It can also be used as a crude measure of response in Hodgkin’s lymphoma.
ESR levels are used to define one of the several possible adverse prognostic factors in the staging of Hodgkin’s lymphoma.
ESR values tend to rise with age and to be generally higher in women. Higher values are often found in states of anemia
A recent study has found the range of ESR between age of 20 to 90 years as 12-19(mm/hr) in males and 18-23 in females.
At birth value of ESR has been found as 1-2 and rises to to 4 mm/hr 8 days after delivery and then to 17 mm/hr by day 14.
It varies between range of 3-20 till puberty.
Pediatric Crohn Disease Activity Index (PCDAI)