Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
CRP was first identified in the 1930’s and consists of a pentameric ring with each monomer containing 206 amino acid residues. It is produced by the liver in response to Interleukin-6, which is released from macrophages during the inflammatory response. It acts by binding to damaged cell membranes and activating the complement pathway. It is a non-specific marker of inflammation so does not indicate the organ or organs affected. It is used for the assessment of the presence or extent of inflammation where there are no obvious clinical signs.
The half-life of CRP is short (a matter of hours), such that a falling level is evidence of disease resolution. Retesting should not be at <24hr intervals.
CRP may be elevated in chronic inflammation so measurement is only of value in diagnosing exacerbations or remissions when previous results are available.
It is now recognised that chronic low-level elevations of CRP in the absence of acute illness are a risk factor for cardiovascular disease.
Specimen container paediatric:
Serum (SST or plain tube)
Specimen container adult:
Serum (SST or plain tube)
Minimum volume paediatric:
0.5 mL blood
Minimum volume adult:
1 mL blood
Sample stability:
Unseparated sample: 3 daysSeparated:
at +15° to +25°C 11 days
at +2° to +8°C 2 months
at -15° to -25°C 3 years
Reference ranges:
0 – 5 mg/L
Other info:
Lithium heparin plasma sample also acceptable