HIGHLY SENSITIVE C-REACTIVE PROTEIN   ( HS-CRP)

What is HS-CRP?  HS-CRP is considered an acute phase reactant or a substance within the  bloodstream that is increased during an inflammatory process. 

What does an increase in HS-CRP signify?  HS-CRP has been used for many years as a marker of inflammation.  In the last few years it has become clear that an assay for C-reactive protein that is much more sensitive than the routine assay can determine the relative levels of C-reactive protein in what was considered the normal range. HS-CRP is one of the more specific markers of risk. When HS-CRP is elevated in the baseline state,  the risk of developing atherosclerotic vascular disease is anywhere from 3-6 times higher than the average population. Atherosclerotic vascular disease is felt to be an inflammatory process.  Inflammation is a very complex cellular and molecular process.  There is no question that atherosclerotic vascular disease involves multiple inflammatory cells, molecules, and substances and  elevation in highly sensitive C-reactive protein is a marker for this inflammatory process.  Whether HS-CRP is directly involved in the development of atherosclerosis  is not clear.  What is clear is that HS-CRP is a marker of risk. 

Measuring HS-CRP HS-CRP C-reactive protein should be measured in the absence of overt inflammation, in particular a cold, on-going infection or some other obvious inflammatory process.  HS-CRP measured by the routine assay has no value in predicting the risk of an atherosclerotic event.  Thus the highly sensitive C-reactive protein is a very specific assay and must be ordered directly.  The highly sensitive C-reactive protein assay can determine whether there is a very mild elevation in the baseline C-reactive protein.  

What is the therapy for elevated HS-CRP?   There is no direct therapy for highly sensitive C-reactive protein.  Increases in HS-CRP signify an increased risk of suffering an Atherosclerotic event.   The intensity of risk factor modification should pursue accordingly.   In other words, all other risk factors including diet, exercise, blood pressure, LDL, and HDL should be treated more intensely  when HS-CRP is increased.

Who should have their HS-CRP determined ?   Individuals who would benefit from having a highly sensitive C-reactive protein determined would include individuals who are not clearly high or low risk in which therapy is being determined.  Certainly not all individuals would benefit from determination of highly sensitive C-reactive protein.  In other words, any individual who is clearly at a high or low risk would not benefit from HS-CRP assay because a therapeutic course has already been determined.