C-REACTIVE PROTEIN (CRP), WRHA & Westman Lab (ROCHE) - (P) or (S)

Test Code: RCRP

Test performed by Chemistry - Westman Lab, Health Sciences Centre (HSC) and St. Boniface Hospital (SBH) using an immunoturbidimetric technique on the Roche Cobas.

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)

_SH Biochemistry Hematology Requisition (R250-10-92)

_SH Hospital Biochemistry Hematology Non Winnipeg Brandon (R250-10-91)

_SH Winnipeg Brandon Biochemistry Hematology Requisition (R250-10-94)

_SH Winnipeg Brandon Hospital Biochemistry Hematology Requisition (R250-10-93)

< 5.0 mg/L
 
Note:  Reference ranges are specific to intrumentation/site where testing performed.  For testing performed at different sites (other than HSC, SBH and Westman Labs), please refer to the appropropriate Lab Information Manual (LIM) entry.

Routine

NICU may order STAT. 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.