ESR (Erythrocyte sedimentation rate) is a type of blood test that measures how quickly erythrocytes (red blood cells) settle at the bottom of a test tube that contains a blood sample. Normally, red blood cells settle relatively slowly. A faster-than-normal rate may indicate inflammation in the body. Inflammation is part of your immune response system.The erythrocyte sedimentation rate (ESR or sed rate) is the rate at which red blood cells sediment in a period of one hour. It is a common hematology test, and is a non-specific measure of inflammation. To perform the test, anticoagulated blood was traditionally placed in an upright tube, known as a Westergren tube, and the rate at which the red blood cells fall was measured and reported in mm at the end of one hour.
Stages in erythrocyte sedimentation (ESR)
When anticoagulated blood is allowed to stand in a narrow vertical glass tube, undisturbed for a period of time, the RBCs – under the influence of gravity- settle out from the plasma. The rate at which they settle is measured as the number of millimeters of clear plasma present at the top of the column after one hour(mm/hr). This mechanism involves three stages:
- Stage of aggregation – It is the initial stage in which piling up of RBCs takes place. The phenomenon is known as Rouleaux formation. It occurs in the first 10-15 minutes.
- Stage of sedimentation – It is the stage of actual falling of RBCs in which sedimentation occurs at constant rate. This occurs in 30-40 minutes out of 1 hour, depending upon the length of the tube used.
- Stage of packing – This is the final stage and is also known as stationary phase. In this, there is a slower rate of falling during which packing of sedimented RBCs in column occurs due to overcrowding. It occurs in final 10 minutes in 1 hour.
Methods of ESR
There are two main methods to determine ESR
- Wintrobe’s method
- Westergren’s method
Each method produces slightly different results. Mosely and Bull (1991) concluded that Wintrobe’s method is more sensitive when the ESR is low, whereas, when the ESR is high, the Westergren’s method is preferably an indication of patient’s clinical state.
Normal Value of ESR
For males : 0-9 mm/hr
For females 0-20 mm/hr
- mm / hour. (Wintrobe method)
- Male
- < 50 years of age = 0 to 9 mm/hour.
- >50 years of age = 0 to 20 mm/hour.
- Female
- <50 years of age = 0 to 20 mm/hour.
- Children = 0 to 13 mm/hour.
| High ESR/Low CRP | Low ESR/High CRP |
|---|---|
| Systemic lupus erythematosisBone and joint infections
Ischemic stroke Waldenstrom’s macroglobulinemia Multiple myeloma IgG4 related disease Renal insufficiency Low serum albumin |
Urinary tract, GI, lung and bloodstream infectionsMyocardial infarction
Venous thromboembolic disease Rheumatoid arthritis Low serum albumin |
How to do ESR (Procedure)
- ESR should be done within 2 hours of the collection of the blood.
- Blood can be kept at 4 C for 6 hours. Now bring the blood to room temperature.
- Take 0.2 mL of ESR solution + 1.8 mL of oxalate blood or blood in EDTA.
- Fill the Wintrobe ESR tube. (mix the blood thoroughly before filling the tube).
- Mount in the ESR stand.
- Start the clock for one hour.
- Record the result after one hour.
- That is the ratio of settled cells and above clear plasma.
- The temperature should be kept between 20 to 25 C.
ESR Test Results Means
Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you.
ESR is measured in millimeters per hour (mm/h). The normal values are
- 0 to 10 mm/h in children
- 0 to 15 mm/h in men younger than 50
- 0 to 20 mm/h in men older than 50
- 0 to 20 mm/h in women younger than 50
- 0 to 30 mm/h in women older than 50
ESR above 100 mm/h is most likely caused by an active disease. For instance, you may have
High ESR Test Results
There are multiple causes of a high ESR test result. Some common conditions associated with high rates include:
- Infection
- Rheumatoid arthritis
- Rheumatic fever
- Vascular disease
- Inflammatory bowel disease
- Heart disease
- Kidney disease
- Certain cancers
- Anemia
- Bone infection
- Heart infection
- Heart valve infection
- Skin infection
- Systemic infection
- Tuberculosis
- Multiple myeloma
- Nephritis
- Pulmonary embolism
- Rheumatic fever
- matoid arthritisSubacute bacterial endocarditis
- Temporal arteritis
- Lymphoma
- Pregnancy
- Temporal arteritis
- Thyroid disease
- Waldenstrom’s macroglobulinemia
- Drugs like birth control pills, methyldopa (Aldomet), theophylline (Theo-24, Theolair, Elixophylline), vitamin A, cortisone, and quinine
ESR test results that are higher than normal are also associated with autoimmune disorders, including:
- systemic lupus erythematosus
- rheumatoid arthritis
- giant cell arteritis
- polymyalgia rheumatica
- primary macroglobulinemia
- too much fibrinogen in your blood, or hyperfibrinogenemia
- allergic or necrotizing vasculitis
Low ESR Test Results
A low ESR test result may be due to
- Congestive heart failure
- Hypofibrinogenemia
- Leukocytosis
- Low plasma protein
- Polycythemia
- Sickle cell anemia
- Urinary tract, GI, lung and bloodstream infections
- Myocardial infarction
- Polycythemia
- Sickle cell anemia
- Leukocytosis, an abnormal increase in white blood cells
- Venous thromboembolic disease
- Low serum album
Factors influencing ESR
Plasma protein
- In normal blood RBCs suspended in the plasma from few aggregates of RBCs. So the rate of sedimentation is slow.
- If there is a rouleaux formation that will give a false value. So acute phase protein affects the ESR.
Number of RBCs
- ESR depends upon the number of RBCs like in anemia decreased the number of RBCs settles down rapidly.
- In the case of polycythemia, RBCs settles slowly and ESR will be low.
Shape of RBCs
- Changes in the shape affect the ESR like in Sickle cell anemia, ESR may low or zero.
Size of the RBCs
- Macrocytes cells settle more rapidly than the microcytes because of their large size.
References
- https://www.ncbi.nlm.nih.gov/pubmed/25290132
- https://www.ncbi.nlm.nih.gov/pubmed/9590999
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5047224/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4614602/
- https://www.ncbi.nlm.nih.gov/pubmed/19552971
