C-REACTIVE PROTEIN (CRP), Rural Sites (ORTHO), excluding Westman Lab - (P)

Test Code: CRP

Testing performed by Clinical Biochemistry & Genetics - The Pas, Flin Flon & Thompson using an enzymatic immunoassay on the Ortho Vitros.

CRP  test measures level of C-reactive protein, one of several proteins produced by the liver during the acute inflammatory phase.  It increases quickly, early in the inflammatory process, and also clears quickly as the insult resolves.
 
CRP and ESR:
- Because of their non-specific nature, their diagnostic value is minimal, particularly in an emergency setting. A competent history and physical examination yield much more useful diagnostic information.
- Should not be used as screening tests for disease.
- ESR and CRP may be normal in serious illnesses, including serious infections, temporal arteritis and autoimmune disease, and malignancies.
- ESR increase lags behind leukocytosis and neutrophilia in acute bacterial infections, and remains elevated after resolution. It contributes little to diagnosis and may direct unnecessary prolongation of therapy.
- ESR or CRP are of questionable utility in the initial diagnosis of systemic inflammatory/rheumatic disease, but may be helpful during management/follow up.
- ESR and CRP are often, but not always, highly elevated in temporal arteritis and in polymyalgia rheumatica. A negative or lower ESR does not exclude these conditions if findings are supportive. Therefore, the clinical setting must guide management timing over ESR or CRP results.

This test is designed for use as an indicator of acute inflammation and not for cardiac risk assessment or stratification.
 

Clinical Practice Change - Change in ESR/CRP Availability (Effective May 16, 2017)

0 - 8.0 mg/L
 
Note:  Reference ranges are specific to instrument/site where testing performed.  For testing performed at different sites (other than The Pas, Flin Flon & Thompson), please refer to the appropriate Lab Information Manual (LIM) entry.

Daily

ESR and CRP offer similar information. There is no advantage in requesting both. The laboratory will honor one of these requests and cancel the other if both are ordered. Please contact the hematopathologist or biochemist on service to discuss any exception to this.

Not to be confused with High-Sensitivity C-Reactive Protein.  Above assay is not useful for Cardiovascular Risk Assessment.