In Europe many many doctors test for CRP instead of Hs-CRP.
Both the CRP and hs-CRP tests measure the amount of C-reactive protein circulating in the blood, so they both measure the same thing. The high-sensitivity CRP test was developed to more accurately detect lower levels of CRP that may be relevant.
C-reactive protein (CRP) is an acute-phase reactant produced by the liver. It increases with inflammation and bacterial infection, though it doesn’t necessarily increase with a viral infection. CRP is nonspecific in that it indicates the presence of inflammation but not the cause. Synthesis may be promoted by trauma, fungi, bacteria, and antigen-immune complexes. Elevations in CRP predict cardiovascular events better than LDL cholesterol does (Pagana 2019).
The newer hs-CRP assay is better able to detect and measure CRP at lower levels though it may be more variable and should be repeated to optimize assessment.
Levels of hs-CRP were found to significantly correlate with the severity of atherosclerosis. Subjects with atherosclerosis had a mean hs-CRP of 0.87 mg/L while those with atherosclerosis had a mean hs-CRP of 1.46 mg/L (Swastini 2019).
Conventional ranges
CRP
- less than 8 m/L (76 nmol/L)
hs-CRP
- less than 1 mg/L = lower relative cardiovascular risk (9.5 nmol/L)
- 1.1-3 mg/L = Average relative cardiovascular risk (10.5-28.6 nmol/L)
- 3.1-10 mg/L = Higher relative cardiovascular risk. (29.5-95.2 nmol/L). Consider retesting in 1 to 2 weeks to exclude a benign transient elevation in the baseline CRP value secondary to infection or inflammation.
- Greater than 10 mg/L = Persistent elevation, upon retesting, may be associated with infection and inflammation.
Optimal ranges
CRP
- 0.00-4.5 mg/L (42.9 nmol/L)
hs-CRP
- Female: 0-1 mg/L (0-9.52 nmol/L)
- Male: 0-0.55 mg/L (0-5.24 nmol/L)
References
Pagana, Kathleen Deska; Pagana, Timothy J.; Pagana, Theresa N. Mosby's Diagnostic and Laboratory Test Reference. Elsevier Health Sciences. 2019.
Quest Diagnostics CRP, hs-CRP.
Swastini, Dewa Ayu et al. “Atherosclerosis Prediction with High Sensitivity C-Reactive Protein (hs-CRP) and Related Risk Factor in Patient with Dyslipidemia.” Open access Macedonian journal of medical sciences vol. 7,22 3887-3890. 14 Nov. 2019, doi:10.3889/oamjms.2019.526