Interleukin-6, Highly Sensitive, ELISA

The Interleukin-6, Highly Sensitive, ELISA test contains 1 test with 1 biomarker.

Brief Description: The Interleukin-6 (IL-6) test is a blood test that measures the level of IL-6, a cytokine, in the bloodstream. Cytokines are small proteins released by cells, particularly those in the immune system, which play crucial roles in cellular communication, inflammation, and the immune response. IL-6 is an inflammatory cytokine, meaning it promotes inflammation and can be produced in response to infections, injuries, and other stressors.

Also Known As: IL-6 Test, Interleukin-6 Serum Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is an Interleukin-6 test ordered?

Doctors might order the IL-6 test when they suspect conditions related to systemic inflammation or to monitor the inflammatory status of certain diseases. Reasons include:

1. Inflammatory Conditions: To identify or monitor conditions like rheumatoid arthritis or systemic lupus erythematosus.
2. Infections: Particularly severe infections or sepsis, where IL-6 levels can rise significantly.
3. Cytokine Release Syndrome (CRS): A severe systemic inflammatory response seen after certain treatments, such as CAR T-cell therapy for cancers.
4. COVID-19: Elevated IL-6 has been observed in patients with severe COVID-19 and may indicate a more severe inflammatory response.

What does an Interleukin-6 blood test check for?

Immune cells create a protein called interleukin-6. The IL-6 test may be helpful as a marker of immune system activation since it aids in the regulation of immunological responses. Inflammation, infection, autoimmune conditions, cardiovascular conditions, and some leukemias can all cause an increase in IL-6. The test quantifies the blood's level of IL-6.

One of the substances referred to as cytokines is interleukin-6. The body's cytokines have a variety of functions, but they work particularly in the immune system to guide the body's immunological response. They are a part of the coordinated, successive activation of immune response pathways known as the "inflammatory cascade".

White blood cells produce IL-6, which affects a range of cells and tissues. It encourages B-cell differentiation, boosts some types of cell proliferation while inhibiting others. Acute phase proteins are produced more actively as a result. In addition to controlling body temperature, IL-6 also helps the brain and bones stay healthy. Although it can be anti-inflammatory, it is mostly pro-inflammatory.

Other Lab Tests Ordered Alongside the Interleukin-6 Test

When a Highly Sensitive IL-6 test is ordered, it's often part of a broader evaluation of inflammatory processes, immune responses, and specific disease states. Here are some tests commonly ordered alongside it:

1. C-Reactive Protein (CRP), especially High-Sensitivity CRP (hs-CRP):

   • Purpose: To detect and measure inflammation levels in the body.
   • Why Is It Ordered: CRP is a general marker of inflammation and can be elevated in similar conditions as IL-6, helping to confirm the presence and severity of inflammation.

2. Erythrocyte Sedimentation Rate (ESR):

   • Purpose: To measure the rate at which red blood cells settle at the bottom of a test tube, indicating the presence of inflammation.
   • Why Is It Ordered: ESR is another non-specific marker of inflammation and is often used in conjunction with other tests to assess inflammatory conditions.

3. Complete Blood Count (CBC) with Differential:

   • Purpose: To evaluate overall blood health.
   • Why Is It Ordered: To identify signs of infection, anemia, or other blood-related issues often associated with inflammatory and autoimmune diseases.

4. Tumor Necrosis Factor-alpha (TNF-α):

   • Purpose: To measure levels of TNF-α, a pro-inflammatory cytokine.
   • Why Is It Ordered: Like IL-6, TNF-α is a key player in inflammatory processes and is often elevated in chronic inflammatory and autoimmune conditions.

5. Antinuclear Antibody (ANA) Test:

   • Purpose: To detect antibodies that target the body’s own tissues, indicating an autoimmune process.
   • Why Is It Ordered: To screen for autoimmune diseases, such as lupus or rheumatoid arthritis, which can cause elevated IL-6 levels.

6. Rheumatoid Factor (RF) and Anti-Cyclic Citrullinated Peptide (Anti-CCP) Antibodies:

   • Purpose: To detect specific antibodies associated with rheumatoid arthritis.
   • Why Is It Ordered: To help diagnose rheumatoid arthritis, a condition often associated with increased IL-6 levels.

7. Serum Protein Electrophoresis (SPEP):

   • Purpose: To analyze the different proteins in the blood.
   • Why Is It Ordered: To identify abnormal protein production, such as monoclonal gammopathy, which can be associated with certain cancers and chronic inflammatory conditions.

8. Liver Function Test:

   • Purpose: To assess liver health.
   • Why Is It Ordered: Liver diseases can impact and be impacted by systemic inflammation and cytokine levels, including IL-6.

These tests, when ordered alongside a Highly Sensitive IL-6 test, provide a comprehensive evaluation of inflammatory and autoimmune conditions, as well as help in assessing the risk and severity of infections and certain cancers. They are crucial for diagnosing and managing these conditions, understanding the underlying cause of inflammation, and guiding appropriate treatment. The specific combination of tests will depend on the individual’s symptoms, clinical presentation, and medical history.

Conditions or Diseases that Require the Interleukin-6 Test

Several conditions or diseases might be associated with elevated IL-6 levels:

• Rheumatoid Arthritis: IL-6 plays a role in the joint inflammation characteristic of this autoimmune disease.
• Systemic Lupus Erythematosus (SLE): Another autoimmune disease where IL-6 can contribute to inflammation.
• Castleman Disease: A rare disorder characterized by enlarged lymph nodes and increased IL-6.
• Cytokine Release Syndrome: A potential side effect of certain immunotherapies.
• Sepsis: A systemic inflammatory response to infection.
• COVID-19: Particularly in severe cases with an excessive immune response.

How does my health care provider use an Interleukin-6 test?

Interleukin-6 can be used to assess someone who has a disorder like lupus, rheumatoid arthritis, or sepsis, which is connected to inflammation or infection. Moreover, it might be employed to assess diabetes or cardiovascular disease.

A cytokine, or immune cell-produced protein, known as IL-6 works on other cells to assist control and/or enhance an immune response. Moreover, it promotes the synthesis of acute phase reactants, proteins that rise in blood levels in response to inflammation or tissue damage.

What do my Interleukin-6 test results mean?

In the blood, IL-6 is typically undetectable or hardly detectable.

An increased IL-6 level may indicate that the subject of the test has an inflammatory disease. IL-6 is high with a range of illnesses and has been connected in some circumstances with an increased risk of disease onset or worsening prognosis. There may be an increase in IL-6 in the following circumstances:

• Lupus
• Rheumatoid arthritis
• Autoimmune conditions
• Infections
• Cardiovascular disease
• Diabetes

Most Common Questions About the Interleukin-6 test:

Purpose and Indications for the Interleukin-6 (IL-6) Test

Why is the Interleukin-6 (IL-6) test ordered?

The Interleukin-6 (IL-6) test is ordered to evaluate the level of IL-6 in the blood. IL-6 is a cytokine, a type of protein involved in cell signaling, that can be elevated in certain inflammatory conditions, infections, autoimmune disorders, and some types of cancer.

What conditions are commonly associated with elevated IL-6 levels?

Conditions such as rheumatoid arthritis, systemic lupus erythematosus, and Castleman disease can lead to increased IL-6 levels. Additionally, IL-6 may be elevated in some cancers, like multiple myeloma and lymphoma, as well as during certain infections.

Interpreting the Results

What do elevated levels of IL-6 indicate?

Elevated levels of IL-6 generally indicate inflammation or an ongoing immune response. It can be indicative of an inflammatory condition, an autoimmune disorder, an infection, or a malignancy. The specific cause often requires interpretation in conjunction with other tests and clinical findings.

Can IL-6 levels be used to monitor treatment response?

Yes, in some conditions, like rheumatoid arthritis or Castleman disease, monitoring IL-6 levels can provide insights into how effectively the treatment is reducing inflammation or disease activity.

Follow-up and Treatment

How can the results from the Interleukin-6 (IL-6) test influence treatment decisions?

If IL-6 levels are found to be elevated, it might prompt the physician to consider treatments that target IL-6 or its signaling pathways. For instance, tocilizumab is a medication that inhibits IL-6 and is used in the treatment of rheumatoid arthritis and other conditions.

Disease Monitoring and Complications

How often should the Interleukin-6 (IL-6) test be repeated if initial levels are high?

The frequency of repeat testing depends on the clinical scenario. For instance, in a patient with rheumatoid arthritis on treatment, IL-6 levels might be checked periodically to monitor treatment efficacy. However, the frequency is individualized based on disease activity and the treating physician's judgment.

Additional Information

Does the Interleukin-6 (IL-6) test replace other tests for diagnosing inflammatory or autoimmune conditions?

No, the Interleukin-6 (IL-6) test is often used in conjunction with other tests and is part of a broader diagnostic workup. It provides additional information about the body's inflammatory state but is not diagnostic on its own.

Are there any other cytokines or proteins that are tested alongside IL-6?

Yes, other cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) might also be tested, depending on the suspected condition, to give a more comprehensive view of the inflammatory and immune status.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.