Estimation of Erythrocyte Sedimentation rate

 

What is an ESR test?

•       An erythrocyte sedimentation rate (ESR) test is sometimes called a sedimentation rate test or sed rate test. This blood test doesn’t diagnose one specific condition. Instead, it helps your healthcare provider determine whether you’re experiencing inflammation. The ESR test can also be used to monitor inflammatory diseases.

•       When person experiencing inflammation, red blood cells (RBCs) cling together, forming clumps. This clumping affects the rate at which RBCs sink inside a tube where a blood sample is placed.

•       The test is to see how much clumping is occurring. The faster and further the cells sink towards the bottom of a test tube, the more likely it is that inflammation is present. However, it doesn’t help pinpoint the cause of inflammation.

•       The ESR test can be used to help your healthcare provider diagnose conditions that cause inflammation, such as: Autoimmune diseases, Cancers, Infections, Rheumatoid arthritis (RA), Systemic lupus erythematosus (SLE), Certain muscle or connective tissue problems, such as polymyalgia rheumatic, Arthritis or inflammatory bowel disease (IBD).

Preparing for the ESR test

•       The ESR test requires little preparation.

•       However, you should tell your doctor if you’re taking any medication therapy. They may ask you to temporarily stop taking it before the test. Certain medications may affect ESR test results.

The ESR test

•       This test involves a simple blood draw. It should take only a minute or two.

•       First, the skin directly over your vein is cleaned.

•       Then, a needle is inserted to collect your blood.

•       After collecting your blood, the needle is removed and the puncture site covered to stop any bleeding.

•       The blood sample is taken to a lab, where your blood will be placed in a long, thin tube in which it sits to gravity for one hour.

 

Different types of ESR tests

•       There are two methods for measuring your erythrocyte sedimentation rate. 

(1) Westergren method, 

(2) Wintrobe method.

Westergren Method

•       In this method, your blood is drawn into a Westergren-Katz tube until the blood level reaches 200 millimeters (mm).

•       The tube is stored vertically and sits at room temperature for an hour.

•       The distance between the top of the blood mixture and the top of the sedimentation of RBCs is measured.

•       This is the most used ESR testing method.

 

Wintrobe method

•       The Wintrobe method is similar to the Westergren method, except the tube used is 100 mm long and thinner.

•       A disadvantage of this method is that it’s less sensitive than the Westergren method.

 

Understanding abnormal ESR test results

•       The higher the number is the higher the likelihood of inflammation. An abnormal ESR result doesn’t diagnose any particular disease. It just identifies any potential inflammation in your body and indicates a need to look further.

•       An abnormally low value would be near 0. (Because these tests fluctuate, and what is ultimately considered to low may vary from one person to the next, it’s hard to state an exact value.)

•       This test isn’t always reliable or meaningful. Many factors can alter your results, such as:

§  Advanced age

§  Medication use

§  Pregnancy

•       Some causes of abnormal ESR test results are more serious than others, but many aren’t a huge concern. It’s important not to worry too much if your ESR test results are abnormal.

•       Instead, work with your doctor to find out what’s causing your symptoms. They’ll usually order follow-up tests if your ESR results are too high or low.

 

Factors that increases ESR/Causes of high ESR test results

o   Anemia:

§  Anemia increases ESR because the change in erythrocyte-plasma ratio favors rouleaux formation. Rouleaux is aggregation of RBCs together due to their discoid shape. Rouleaux have a decrease surface area and accelerate ESR

o   Increase level of fibrinogen:

§  It decreases the negative charge of erythrocyte, so RBC tend to remain apart and this promotes formation of rouleaux and increase ESR

o   Immunoglobulin:

§  Increase antibody level in blood increase ESR

o   Increase cholesterol level / Obesity

o   Autoimmune diseases Rheumatoid arthritis, Rheumatic fever

o   Chronic infections, Skin infection, Systemic infections

o   Tissue destruction and other disease, Tuberculosis (tb)

o   Advanced age

o   Pregnancy

o   Kidney disease, Thyroid disease

o   Carcinoma, Certain types of cancer, including some types of lymphoma and multiple myeloma

o   An abnormally high ESR can indicate the presence of cancerous tumors, especially if no inflammation is found.

o   Bone infection

o   Heart infections causing myocarditis (affects heart muscle), pericarditis (affects tissue around the heart, or the pericardium) and endocarditis (affects the lining of the heart, which can include the heart valves)

Factors that decrease ESR:

o   De-fibrinigenation:

§  Removal of fibrinogen decreases ESR

o   Increase albumin and lecithin in blood

o   Abnormal or sickle shape RBCs:

§  Abnormal or irregular shape of RBC lower ESR

o   Congestive heart failure

o   Causes of low ESR test results

o   A low ESR test result may be due to:

o   Congestive heart failure (CHF)

o   Hypo fibrinogenemia, which is too little fibrinogen in the blood

o   Low plasma protein (occurring in relation to liver or kidney disease)

o   leukocytosis, which is a high white blood cell (WBC) count

o   polycythemia vera, a bone marrow disorder that leads to the production of excess RBCs

o   Sickle cell anemia, a genetic disease affecting the RBCs

 

 

 

Type	Donor’s	Recipient’s
Major Cross Match	Red Cells	Serum/Plasma
Minor Cross Match	Serum/Plasma	Red Cells

 

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