How is it used?When is it ordered?What does the test result mean?Is there anything else I should know?
The CRP test is useful in assessing patients with:
CRP may be used to screen apparently healthy people for the following conditions. However, in these cases, the more sensitive test hs-CRP will be ordered:
While the CRP test is not specific enough to diagnose a particular disease, it does serve as a general marker for infection and inflammation, thus alerting medical professionals that further testing and treatment may be necessary.
Because CRP increases in severe cases of
inflammation, the test is ordered when
acute inflammation is a risk (such as from an infection after surgery) or suspected based on patient symptoms. It is also ordered to help evaluate conditions such as
rheumatoid arthritis and
lupus and is often repeated to determine whether treatment is effective. This is particularly useful for inflammation problems since CRP levels drop as inflammation subsides.
CRP also is used to monitor wound healing and to monitor patients who have surgical cuts (incisions), organ transplants, or burns as an early detection system for possible infections.
What does the test result mean?NOTE: This test has no single number that identifies an abnormal result.
Your lab report (see a sample report) should include
a range of numbers (reference range) that identifies what is expected for you based on
your age, sex, and the method used in that laboratory. You can find more information
about expected results at Reference Ranges
and What They Mean. Lab Tests Online strongly recommends that you discuss the meaning of your test results with your doctor.
A high or increasing amount of CRP in your blood suggests that you have an
acute infection or
inflammation.
If the CRP level in your blood drops, it means that you are getting better and inflammation is being reduced.
Is there anything else I should know?
CRP levels can be elevated in the later stages of
pregnancy as well as with use of birth control pills or hormone replacement therapy (i.e., estrogen). Higher levels of CRP have also been observed in the obese.
Another test to monitor inflammation is called the erythrocyte sedimentation rate (ESR). Both tests are elevated in the presence of inflammation; however, CRP appears and then disappears sooner than changes in the ESR. Thus, your CRP level may fall to normal if you have been treated successfully, such as for a flare-up of arthritis, but your ESR may still be abnormal for a while longer.
