Erythrocyte Sedimentation Rate test (ESR)

What is being tested?

The erythrocyte sedimentation rate (ESR or sed rate) is a test that assesses inflammation in the body implicitly. The test examines the rate at which erythrocytes (red blood cells) fall (sediment) in a blood sample that has been deposited into a tall, thin, vertical tube. The millimeters of clear fluid (plasma) present at the upper portion of the tube after one hour are recorded as the result.

When a drop of blood is inserted into a tube, the red blood cells drop out slowly, leaving just a small amount of transparent plasma. In the availability of an increased number of proteins, particularly proteins known as acute phase reactants, red cells settle at a faster pace. Inflammation raises the levels of acute-phase reactants including C-reactive protein (CRP) and fibrinogen in the blood.

Inflammation is a natural aspect of the immune system’s response. It might be acute, manifesting quickly after a shock, injury, or infection, or chronic, manifesting over time with disorders like autoimmune diseases or cancer.

The ESR is not a diagnostic test; it is a non-specific indicator that can be increased in a variety of diseases. It gives you a basic idea of whether or not you have an inflammatory condition.

There have been concerns about the ESR’s use in light of newer, more specialized tests that have become available. The ESR test, on the other hand, is commonly used to diagnose and monitor systemic vasculitis, temporal arteritis, and polymyalgia rheumatica. ESR levels that are extremely high can help with rheumatic disease differential diagnosis. Furthermore, ESR may still be a viable alternative in some cases, such as when updated tests are unavailable in resource-constrained places or while monitoring the progression of a disease.

How is the test used?

The erythrocyte sedimentation rate (ESR or sed rate) is a non-specific, very straightforward test that has been employed for many years to diagnose inflammation in situations like infections, malignancies, and autoimmune diseases.

Because a raised ESR often detects the presence of inflammation but does not inform the healthcare professional where the inflammation is in the body or what is triggering it, it is referred to as a non-specific test. Aside from inflammation, other disorders might affect an ESR. As a result, the ESR is frequently combined with other tests, such as C-reactive protein.

ESR is used to identify systemic vasculitis, temporal arteritis, and polymyalgia rheumatica, among other inflammatory illnesses. One of the key test results used to support the diagnosis is a markedly high ESR.

This test can be used to track disease activity and treatment response in both of the disorders mentioned above, as well as several others including lupus.

When is it ordered?

When a disorder or disease is suspected of generating inflammation in the body, and ESR may be ordered. This test can be used to detect a variety of inflammatory diseases. It may be requested, for example, if arthritis is suspected of producing joint inflammation and pain, or if inflammatory bowel disease is known to cause digestive symptoms.

When a person develops symptoms of polymyalgia rheumatica, systemic vasculitis, or temporal arteritis, such as headaches, shoulder or neck discomfort, pelvic pain, poor appetite, anemia, unexplained weight loss, and joint stiffness, a doctor may recommend an ESR. The ESR can also be ordered on a regular basis to help track the progression of certain disorders.

What happens during an ESR?

A tiny needle will be used to obtain a blood sample from a vein in your arm by a health care provider. A blood specimen will be taken into a test tube or vial once the needle is inserted. When the needle goes in or out, it may hurt a little. It normally takes less than five minutes to complete this task.

What does the test result mean?

The outcome of an ESR is described as the millimeters of clear fluid called plasma that is present at the head portion of the tube after one hour (mm/hr).

Since ESR is a non-specific trademark of inflammation and is influenced by other factors, the proceeds must be used along with other clinical findings, the individual’s wellness history, and results from other laboratory tests. If the ESR and clinical conclusions match, the health practitioner may be able to establish or rule out a suspected diagnosis.

A single raised ESR, without any symptoms of a particular disease, will usually not give enough data to make a medical decision. Moreover, a normal result does not rule out inflammation or infection.

Slightly elevated ESR occurs with inflammation but also with pregnancy, anemia, infection, and aging.

A very elevated ESR usually has an obvious cause, such as a critical infection, marked by an advance in globulins, polymyalgia rheumatica, or temporal arteritis. A health professional will typically use other follow-up tests, like blood cultures, depending on the individual’s symptoms. Somebody with multiple myeloma or Waldenstrom’s macroglobulinemia (tumors that make huge amounts of immunoglobulins) typically have very large ESRs even if they don’t suffer from inflammation.

When observing a condition over time, increasing ESRs may indicate progressing inflammation or a feeble response to therapy; normal or declining ESRs may indicate a suitable response to treatment.

                                     OR

If the ESR is elevated, it may be associated with an inflammatory condition, such as:

  • Infection
  • Heart disease
  • Rheumatoid arthritis
  • Vascular disease
  • Rheumatic fever
  • Inflammatory bowel disease
  • Kidney disease
  • Certain types of cancers

 Seldom the ESR can be slower than usual. A quiet ESR may indicate a blood disorder, such as:

  • Polycythemia
  • Leukocytosis (an abnormal rise in white blood cells)
  • Sickle cell anemia

If the results are not in the ordinary range, it doesn’t certainly mean you have a medical situation that requires treatment. A fair ESR may indicate menstruation, pregnancy, or anemia, instead of inflammatory disease. Some medicines and supplements can also change your results. These include oral contraceptives, cortisone, aspirin, and vitamin A. Be certain to notify your health care provider about any medications or supplements you are in use with.

Risks of the ESR test

The hazards of having your blood collected are minor. Complications that may arise include:

Bleeding can range from minor to severe.

  • fainting
  • bruising
  • hematoma
  • vascular inflammation
  • tenderness
  • dizziness
  • infection

When the needle pricks your skin, you’ll probably experience mild to moderate pain. After the test, you may have aching at the puncture site.

Different types of ESR tests

The erythrocyte sedimentation rate can be measured in two ways.

  1. Westergren method-

Blood is taken into a Westergren-Katz tube until the level of blood reaches 200 millimeters in this procedure (mm).

The tube is kept vertically and allowed to sit for an hour at room temperature.

It is measured the distance between the tip of the blood mixture and the tip of the RBC sedimentation.

This is the most common method of ESR testing.

  1. Wintrobe method-

The Wintrobe model is applicable to the Westergren method, but with a 100 mm long and thinner tube.

This method has the disadvantage of being less sensitive than the Westergren method.

Other tests

The sed rate test can simply indicate to your doctor that you have inflammation in your body. It is unable to determine the location of the inflammation or the etiology of the inflammation. To aid in the diagnosis, your doctor may perform an erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) test. Both are acute phase reactants, or inflammatory indicators, that can aid in the diagnosis or treatment of a condition. To make a specific diagnosis, you’ll still require imaging or maybe a biopsy.

ESR and cancer

  It has been confirmed that there is a connection between chronic inflammation and carcinogenesis and that subclinical or even undetectable inflammation may be as important as chronic inflammation in enhanced cancer risk, cancer development, and cancer progression. Chronic inflammation may encourage excessive cell proliferation and activate a cascade of cellular events, increasing tumor cell growth. Moreover, tumor progression per se may also excite host immune response and inflammation.

Erythrocyte sedimentation rate (ESR) is the most extensively used laboratory test for assessing the inflammatory status in clinical practice, including autoimmune plus malignant diseases and also infection. High ESR is frequently encountered in cancer patients. The result in various malignancies depends on the type of the underlying malady, the stage and term of the disease, and the regimen and strength of the antitumor treatment. Additionally, an elevated ESR level has also been recognized as a prognostic factor adversely affecting remainder in cancer patients. A number of investigations indicated that an increased ESR level is correlated with worse survival; patients with higher ESR values in many malignancies, including colorectal cancer, renal cell cancer, head cancer, and neck cancer, soft tissue sarcoma, breast cancer, glioma, and prostate cancer, had lower survival compared with those with regular ESR levels.

Although there has been satisfactory data on other types of tumors, to the best of our understanding, the prognostic value of ESR in melanoma patients has not been sufficiently investigated and the significance of raised ESR levels in melanoma patients has not been fully interpreted. But, increased ESR levels have been distinguished as an adverse prognostic factor for survival in melanoma patients as a subsequent finding when various parameters were investigated in the earlier published trials