One thing that most people do not know that there are other tests physicians can do to monitor changes in lupus activity and the effectiveness of your medications. Which all my years with lupus not one doctor told me this. However, a naturopathic did.
Erythrocyte Sedimentation Rate (ESR)
The erythrocyte (or, red blood cell) sedimentation rate (ESR) is a test that measures the amount of inflammation in your body. Erythrocyte is another word for red blood cell. The erythrocyte (or, red blood cell) sedimentation rate (ESR) is a test that measures the amount of inflammation in your body. For the test, blood is drawn from a vein in your arm into a special tube. The rate of fall (sedimentation) of red blood cells is then measured, as the red blood cells become sediment at the bottom of the tube, leaving blood plasma at the top of the column. The results are reported in terms of how many millimeters of clear blood plasma are present at the top of the column after one hour. Usually red blood cells fall slowly so that there is little clear plasma left at the top. However, when the blood contains higher amounts of certain proteins involved in inflammation, namely fibrinogen and immunoglobulins (antibodies), the red blood cells fall more rapidly, resulting in an increased ESR. Therefore, sedimentation rate increases with more inflammation. A normal ESR is usually about 0-20 millimeters per hour in females and 0-12 millimeters per hour in males. The ESR is nonspecific, meaning that it does not tell your doctor exactly where the inflammation is occurring in your body and is thus not a very strong indicator of lupus activity.
C-reactive Protein (CRP) / Westergren Sedimentation Rate
Like the erythrocyte sedimentation rate, the C-reactive protein (CRP) test measures inflammation. However, CRP usually changes more rapidly than ESR because it is made by the liver and secreted hours after the beginning of infection or inflammation. CRP plays a part in your immune response by interacting with your body’s complement system. The CRP is non-specific, meaning it cannot give your doctor information about where inflammation is occurring in your body. However, the amount of CRP can give an idea as to the degree of inflammation your body is experiencing, and it is used by doctors in lupus treatment to monitor flares and to assess how well your medications are working. It is important to realize, though, that a low CRP value does not necessarily mean that an individual is experiencing no inflammation; a low CRP can be seen in lupus patients with active inflammation. An elevated CRP can also be seen after someone has a heart attack, surgical procedure, or infection.
High Sensitivity C-Reactive Protein (HS CRP)
In apparently healthy individuals, studies have shown that C-reactive protein (CRP) can be an indicator of the risk of cardiovascular disease (CVD), since certain types of CVD, namely atherosclerosis, are known to involve inflammation. A high sensitivity test (high sensitivity C-reactive protein, or HS CRP) is used to evaluate this risk, because the level of CRP in the blood is low. The high sensitivity CRP is important because studies have shown that lupus patients have higher levels of atherosclerosis than the general population. However, the HS CRP can reflect many things in lupus patients besides lupus activity and/or one’s risk of heart attack.
For the HS CRP test, blood is taken from a vein in your arm and mixed with a substance called an antiserum. The antiserum contains a specific substance that is able to detect the CRP. The American Heart Association and Centers for Disease Control and prevention maintain that a high-sensitivity CRP of less than 1.0 mg/L suggests a low risk for CVD, 1.0-3.0 mg/L suggests an average risk, and a CRP above 3.0 mg/L suggests a high risk.
Creatine Phosphokinase (CPK)
Creatine phosphokinase (a.k.a., creatine kinase, CPK, or CK) is an enzyme (a protein that helps to elicit chemical changes in your body) found in your heart, brain, and skeletal muscles. When muscle tissue is damaged, CPK leaks into your blood. Therefore, high levels of CPK usually indicate some sort of stress or injury to your heart or other muscles. To test CPK, blood is drawn from a vein in your arm. In the hospital, a person’s CK-MB level is often checked when they exhibit signs of heart attack. However, in lupus treatment, an elevated CPK may suggest muscle inflammation due to disease activity or an overlapping condition. CPK levels can also be high after strenuous exercise, so your doctor may wish to recheck your CPK after several days of rest. If your CPK is high with no exercise or remains high with rest, your doctor may order additional tests to determine which type (isoenzyme) of CPK is elevated. This information will help her/him to determine the source of the damage (skeletal muscles, heart, or brain). Certain medications, such as statins, can cause increases in CPK, so be sure to tell your doctor about any medications you currently take.
The Coombs’ test is used to detect antibodies that act against the surface of your red blood cells. The presence of these antibodies indicates a condition known as hemolytic anemia, in which your blood does not contain enough red blood cells because they are destroyed prematurely. An acquired form, autoimmune hemolytic anemia (AIHA), is present in about 10% of people with lupus and results from an immune system attack on your red blood cells. A healthy red blood cell lives for about 120 days; in people with hemolytic anemia, red blood cells are destroyed long before the 120-day marker. Sometimes, bone marrow can compensate for the early destruction of red blood cells by working overtime to make more of them. However, this extra effort may not be enough to combat hemolytic anemia.
Hemolytic anemia can either be inherited genetically or acquired. An acquired form, autoimmune hemolytic anemia (AIHA), is present in about 10% of people with lupus and results from an immune system attack on your red blood cells. People with AIHA may experience weakness, dizziness, fevers, and a yellowed complexion. Treatment calls for high doses of steroids such as prednisone, which may be supplemented with immunosuppressive medications such as azathioprine (Imuran).
There are two types of Coombs’ tests: direct and indirect. The direct Coombs’ test, also known as the direct antiglobulin test, is the test usually used to identify hemolytic anemia. The indirect Coombs’ test is used only in prenatal testing of pregnant women and in testing blood prior to a transfusion. For the direct Coombs’ test, blood is drawn from the vein in your arm and then “washed” to isolate your red blood cells. The red blood cells are then incubated (combined in a controlled environment) with a substance called Coombs’ reagent. If the red blood cells clump together (a process called “agglutination”), then the Coombs’ test is said to be positive.