Inflammatory Markers

1. C-Reactive Protein (CRP): A test that measures the concentration of a protein that is only present in cases of acute inflammation in serum as an indicator of acute inflammation. CRP is produced in the liver. The test is performed by drawing blood from a vein, usually from the inside of the elbow. After the puncture site is cleaned, a blood pressure cuff is placed around the upper arm, causing the veins below the band to swell with blood. A needle is then inserted into the vein and the blood collected. Antiserum is then used to detect CRP levels.

   While this is a fairly accurate test, a low CRP level does not mean that there is no acute inflammation. CRP may also be elevated in cases of heart attack and many consider elevated CRP levels to be a positive risk factor for coronary artery disease.

   CRP is not in itself a contributor to coronary artery disease. It is simply a red flag to the inflammation which is now believed to contribute to atherosclerosis.

2. Fibrinogen: Fibrinogen is a protein that makes the blood sticky. During the blood clotting process, the blood-vessel walls or the clotting factors in the blood release a chemical into the bloodstream. This causes fibrinogen, an inert protein found in blood plasma, to be converted into fibrin. The fibrin molecule is unique in its ability to link together, forming long threads that wrap around the platelet plug. The threads act much like a spider-web, catching more platelets, red blood cells, and other substances to form a clot. Fibrinogen levels also become elevated with tissue inflammation or tissue destruction. Thus, the fibrinogen test is a reliable measure of the amount of inflammation occurring in the body. High fibrinogen levels may also be an indicator of an increased risk of heart or circulatory disease. The changing levels of fibrinogen can also be used to monitor the course of an ongoing inflammation – decreased levels indicate an improvement, while increases are indicative of a worsening condition.

   The fibrinogen test involves taking a blood sample. Normal reference ranges for an adult are 200-400 mg/dL. Risks for the test are minimal, involving slight bleeding from the extraction site. However, people with active bleeding, acute infection or illness should not take this test.

   Unlike CRP, Fibrinogen is believed to be a direct contributor to atherosclerosis. However, there are currently no medical treatments available to lower fibrinogen levels.

3. Interleukin-6: Interleukin-6 (IL-6) is a cytokine (a chemical which enables communication between cells) which is secreted by T Cells and macrophages as part of the immune inflammation response to trauma. The body makes CRP from IL-6. Elevated levels of IL-6, then, are a reliable indicator of the amount of inflammation occurring in the body. A blood test is used to ascertain the IL-6 level in the body.

   Adipose tissues make large amounts of IL-6. Increased blood sugar levels also lead to more manufacture of IL-6. Overweight and high blood sugar levels are well known predictors of heart disease. Many in the medical community believe that the inflammation resulting from enhanced IL-6 production is a major contributor to this and other cardiovascular problems. High IL-6 levels have also been found in people with Alzheimer’s disease. (Alzheimer’s is increasingly being seen as an inflammatory brain disorder).