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C-reactive protein (CRP) in serum/plasma

Reference values: - < 1.0 mg/L - 1.0-3.0 mg/L (moderate risk for heart disease)* - > 3 mg/L mg/L (high risk for heart disease)* - > 10 mg/L suggestive of: a) systemic inflammation b) infection c) trauma # reference values are race & gender-dependent [13] mean CRP 3.0 mg/L blacks vs 2.3 whites, 3.3 women vs 1.8 men * high-sensitivity CRP in serum used for assessing cardiovascular risk; use average of 2 measurements; 2 weeks apart (see guidelines for high-sensitivity CRP testing) Indications: - *assessment of inflammation Clinical significance: 1) C-Reactive protein levels are used to indicate the presence of an inflammatory process that may be caused by bacterial infection or a physiological response 2) serum CRP has better specificity for inflammation than ESR [17] - serum CRP rises & falls in response to inflammation faster than ESR [24] 3) increased CRP serum levels are an independent risk factor for mortality after an acute MI a) HMG CoA reductase inhibitor (statin) therapy appears to attenuate the risk associated with increased CRP [3,9] b) CRP serum levels do not predict response to statins [18] 4) increased CRP may be independent risk factor for cardiovascular disease [5] 5) increased CRP levels (> 0.38 mg/dL) associated with risk of inducible myocardial ischemia [7] in patients NOT receiving statin or beta blocker 6) increased risk of major coronary event in subjects with CRP in top 1/3 of general population [10] 7) little predictive value beyond lipid profile, blood pressure diabetes & smoking status [10,14,16] {traditional risk factors} 8) may be link between metabolic syndrome X & elevated CRP; both predict risk of cardiovascular events, but combined no bettter than either alone [11] 9) CRP may be useful to risk-stratify women with syndrome X [11] 10) during 16 weeks after acute coronary syndrome, serum CRP associated with a greater risk of cardiovascular death & all-cause mortality [26] Increases: 1) conditions associated with marked increase in CRP (> 10 mg/dL) a) infections [15] - septic arthritis - bacterial meningitis - bacterial pneumonia - cellulitis - pyelonephritis - subacute bacterial endocarditis - pelvic inflammatory disease - serious opportunistic fungal or viral infections - erythema nodosum leprosum b) rheumatic diseases - severe rheumatoid arthritis - Still's disease - acute rheumatic fever - vasculitis (polyarteritis nodosa, Wegener's granulomatosis) - severe Crohn's disease - polymyalgia rheumatica c) neoplasia - malignant lymphoma - metastatic carcinoma - sarcoma d) others - pulmonary embolism - thrombophlebitis - surgery - burns - fractures, trauma - fever of unknown origin 2) conditions associated with moderate increase in CRP (1-10 mg/dL) a) infections [15] - acute bronchitis - tuberculosis b) rheumatic diseases - rheumatoid arthritis - Crohn's disease - ankylosing spondylitis - Reiter's syndrome - psoriatic arthritis - systemic lupus erythematosis - Behcet syndrome - scleroderma - dermatomyositis - Sjogren's syndrome - ulcerative colitis - Dressler's syndrome c) neoplasia - leukemia - myeloproliferative disorders - increased risk for lung squamous cell carcinoma in smokers & former smokers, but not never smokers [25] d) others - myocardial infarction - congestive heart failure - graft-vs-host disease - pancreatitis - alcoholic hepatitis - sarcoid - idiopathic pulmonary fibrosis 3) conditions associated with insignificant increase in CRP (< 1 mg/dL) a) infections [15] - aseptic meningitis - otitis media - cystitis - viral hepatitis - uncomplicated viral or fungal infection b) rheumatic diseases - osteoarthritis - chondrocalcinosis - pauciarticular juvenile rheumatoid arthritis c) neoplasia - basal cell carcinoma d) others - angina - stroke - gastritis, peptic ulcer disease - alcohol withdrawal - COPD, asthma - hypertension 4) serum levels also increase with: - obesity - diabetes - metabolic syndrome [23] - estrogen [6] Principle: The CRP pack is used in the DuPont ACA discrete clinical analyzer to quantitatively measure C-Reactive protein levels in serum. The C-Reactive Protein (CRP) method is based on a particle enhanced turbidimetric immunoassay (PETIA) adapted to the DuPont ACA analyzer. The CRP method uses a single-pack, rate technique to measure C-reactive protein. The CRP pack contains latex particles coated with the antibody to C-reactive protein (AbPR). C-reactive protein present in the sample causes aggregation of the latex particles. The rate of aggregation is directly proportional to the concentration of C-reactive protein and is measured turbidimetrically at 340 nm. The concentration is determined by means of a previously prepared lot-specific calibration curve or mathematical function. Specimen: Patient preparation: No special patient preparation is required. Collect blood samples by venipuncture following established good laboratory practices. If the sample is obtained through the infusion set, flush the line thoroughly with saline before taking the blood sample.

Related

C-reactive protein; contains: C-reactive protein(1-205) (CRP PTX1) NycoCard[Tm] CRP Whole Blood

Specific

C-reactive protein (CRP) in serum/plasma high-sensitivity

General

general chemistry test

References

  1. ACA IV Discrete Clinical Analyzer Instrument Manual, Volume 1: Operation, DuPont Company, Wilmington, Delaware, 1984.
  2. ACA IV Discrete Clinical Analyzer Instrument Manual, Volume 3B: Chemistry, DuPont Company, Wilmington, Delaware, 1984.
  3. Journal Watch 21(1):1, 2001 Horne et al J Am Coll Cardiol 36:1774, 2000
  4. Prescriber's Letter 8(8):44, 2001
  5. Journal Watch 23(1):3, 2003 Ridker PM et al, N Engl J Med 347:1557, 2002 PMID: 12432042 - Mosca L, N Engl J Med 347:1615, 2002 PMID: 12432050
  6. Prescriber's Letter 10(2):7 2003
  7. Journal Watch 23(6):46, 2003 Beattie MS et al, Circulation 107:245, 2003 PMID: 12538423
  8. Ridker PM, Am J Cardiol 92(4b):17K, 2003 (review) PMID: 12948872
  9. Ridker PM, Circulation 108:2292, 2003 PMID: 14609996
  10. Journal Watch 24(9):69, 2004 Danesh J, Wheeler JG, Hirschfield GM, Eda S, Eiriksdottir G, Rumley A, Lowe GD, Pepys MB, Gudnason V. C-reactive protein and other circulating markers of inflammation in the prediction of coronary heart disease. N Engl J Med. 2004 Apr 1;350(14):1387-97. PMID: 15070788
  11. Journal Watch 24(22):166-67, 2004 Rutter MK, Meigs JB, Sullivan LM, D'Agostino RB Sr, Wilson PW. C-reactive protein, the metabolic syndrome, and prediction of cardiovascular events in the Framingham Offspring Study. Circulation. 2004 Jul 27;110(4):380-5. Epub 2004 Jul 19. PMID: 15262834
  12. Prescriber's Letter 12(2): 2005 C-reactive Protein and Statin Benefits Detail-Document#: 210208 (subscription needed) http://www.prescribersletter.com
  13. Khera A, McGuire DK, Murphy SA, Stanek HG, Das SR, Vongpatanasin W, Wians FH Jr, Grundy SM, de Lemos JA. Race and gender differences in C-reactive protein levels. J Am Coll Cardiol. 2005 Aug 2;46(3):464-9. PMID: 16053959
  14. Miller M, Zhan M, Havas S. High attributable risk of elevated C-reactive protein level to conventional coronary heart disease risk factors: the Third National Health and Nutrition Examination Survey. Arch Intern Med. 2005 Oct 10;165(18):2063-8. PMID: 16216995
  15. Brahn E, Scoville CD Biochemical markers of disease activity. Baillieres Clin Rheumatol 1988 2:153 PMID: 2458192
  16. Elliot P Genetic Loci Associated With C-Reactive Protein Levels and Risk of Coronary Heart Disease. JAMA. 2009;302(1):37-48 http://jama.ama-assn.org/cgi/content/full/302/1/37?home - Melander O Novel and Conventional Biomarkers for Prediction of Incident Cardiovascular Events in the Community JAMA. 2009;302(1):49-57 http://jama.ama-assn.org/cgi/content/short/302/1/49?home - Shah SH and de Lamos JA Biomarkers and Cardiovascular Disease Determining Causality and Quantifying Contribution to Risk Assessment JAMA. 2009;302(1):92-93 http://jama.ama-assn.org/cgi/content/short/302/1/92?home
  17. Colombet I et al. Agreement between erythrocyte sedimentation rate and C-reactive protein in hospital practice. Am J Med 2010 Sep; 123:863.e7. PMID: 20800157
  18. Heart Protection Study Collaborative Group C-reactive protein concentration and the vascular benefits of statin therapy: an analysis of 20 536 patients in the Heart Protection Study The Lancet, Early Online Publication, 28 January 2011 PMID: 21277016 http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(10)62174-5/fulltext
  19. C-Reactive Protein Laboratory Test Directory ARUP: 50180
  20. C-Reactive Protein Neonatal Laboratory Test Directory ARUP: 50181
  21. CRP, High Sensitivity Laboratory Test Directory ARUP: 50182
  22. Ridker PM, Danielson E, Fonseca FA Rosuvastatin to prevent vascular events in men and women with elevated C-reactive protein. N Engl J Med. 2008 Nov 20;359(21):2195-207 PMID: 18997196
  23. Chirinos JA et al CPAP, Weight Loss, or Both for Obstructive Sleep Apnea. N Engl J Med 2014; 370:2265-2275 PMID: 24918371 http://www.nejm.org/doi/full/10.1056/NEJMoa1306187
  24. Medical Knowledge Self Assessment Program (MKSAP) 17, 18. American College of Physicians, Philadelphia 2015, 2018
  25. Muller DC, Larose TL, Hodge A et al Circulating high sensitivity C reactive protein concentrations and risk of lung cancer: nested case-control study within Lung Cancer Cohort Consortium BMJ 2019;364:k4981 PMID: 30606716 https://www.bmj.com/content/364/bmj.k4981
  26. Mani P, Puri R, Schwartz GG et al Association of Initial and Serial C-Reactive Protein Levels With Adverse Cardiovascular Events and Death After Acute Coronary Syndrome. A Secondary Analysis of the VISTA-16 Trial. JAMA Cardiol. Published online March 6, 2019 PMID: 30840024 https://jamanetwork.com/journals/jamacardiology/fullarticle/2725734

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arthritis panel connective tissue disease panel; collagen disease panel; SLE panel endocrinology 7 analyte panel inflammatory markers (iAGE)