WBC and C-Reactive Protein (CRP)

Definition

The C - reactive protein (CRP) is a plasma protein of hepatic origin, having a major role in the inflammatory reaction. The name derives from its interaction with the C-polysaccharide (CPS) for which it requires calcium ions.1 The CRP measurement is proved to be relevant for the diagnosis and for the prognosis of diseases wherever inflammatory processes are involved.

Structure

CRP belongs to the pentraxin family of calcium-dependent ligand-binding plasma proteins, which also includes too the serum amyloid P component (SAP). This structure is a rare configuration due to the conserved pentameric arrangement of the protomers. Indeed, CRP contents 5 protomers of each 206 amino-acid and its molecular weight is about 23kDa.2

Synthesis process

An acute-phase inflammatory response occurs when the human body triggers a systemic response following tissue injury by infectious, noninfectious, chemical, physical, or immunologic toxin causes. CRP is a protein increasing during the acute-phase response and is regulated by cytokines, like interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF-α), which are known to increase by at least 25% during the inflammatory response. These cytokines stimulate hepatocytes to increase the synthesis and release of positive acute-phase proteins, including CRP. IL-6 is the major cytokine stimulus for CRP production.3

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WBC and C-Reactive Protein (CRP)

Measurement

CRP is a well-established biomarker in clinical laboratories for the diagnosis of inflammation or infection. It is an acute-phase protein whose concentration increases rapidly in response to various stimuli including inflammation, bacterial infection, trauma, surgery. Its measurement in routine analysis has been largely developed.

Many CRP immunoassays are commercially available and, performed on plasma or serum samples, are mainly based on particle-enhanced turbidimetry or nephelometry using latex microbead. This technology has been modified and further adapted to whole blood samples by HORIBA Medical allowing overcome possible interferences with cellular element. Indeed, the instruments of the HORIBA Medical CRP series provide doctors with efficient equipment which allows performing in less than 4 minutes a Complete Blood Count (CBC) or 5-differential (5-DIFF) together with an immunoassay measuring CRP up to 200mg/L. This is a unique solution that has made HORIBA Medical the leader in this field already for more than 15 years.

The determination of all these parameters on a unique blood sample avoids separation of plasma or serum from blood cells and therefore constitutes an important procedure simplification and reduction of analysis time. This is made possible by using of an infrared light source for which cell debris and hemoglobin diffusion/absorption is negligible with respect to the specific signal due to particle aggregates formation in response to the presence of CRP.

Concentration

In normal plasma of healthy people CRP median values are around 1mg/L. However, values of 5-10 mg/L CRP can still be considered normal in healthy people who have no signs of infection or 4 inflammation . In any case, all CRP values must be interpreted in the clinical context. The normal CRP concentration in the elderly may be more elevated than1mg/L.

In apparently healthy people, CRP measures of about 2-3mg/L have been linked to risk of cardiovascular diseases and this range is denominated as high sensitive CRP (hs-CRP).

The serum concentration of CRP increases rapidly within hours upon immunological insult, microbial infection or tissue damage.5 In individuals with acute and severe illness, cytokines, IL-6, stimulate hepatic production of CRP and plasma levels may increase up to 300mg/L or more.

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WBC and C-Reactive Protein (CRP)

Role in Biology

CRP is highly expressed during the acute phase of inflammatory reactions. The protein behaves like an antibody by its several functions associated with host defense: it promotes agglutination, bacterial capsular swelling and phagocytosis, and activates the classical complement pathway through its calcium-dependent binding to phosphocholine.6 Quantitative measure of CRP level in serum has widespread clinical use as sensitive marker of inflammation. The circulating value of CRP reflects ongoing inflammation and/or tissue damage much more accurately than do other laboratory parameters of the acute-phase response, such as plasma viscosity and the erythrocyte sedimentation rate (ESR). CRP is a reliable indicator of acute inflammatory processes than ESR and leukocyte count. Blood CRP levels rise more rapidly than ESR, and after the disease has subsided CRP values rapidly fall and reach the reference interval often days before ESR has returned to normal.

Neonatal sepsis occurs in about 1 to 8 cases/1000 live births.7 Early detection is hampered by vague, nonspecific or nonexistent clinical manifestations. Neonates, especially those born preterm, often fail to induce elevations in temperature and white blood cell (WBC) counts that are the hallmarks of infection in older children. Therefore CRP increase can be used to reveal hidden infections wherever WBC and fever are not reliable as in newborns. In addition CRP doesn’t cross the placenta (or in exceedingly low quantities) differently from procalcitonin (PCT), another protein involved in the inflammatory immune response. Therefore, at birth, CRP elevation in the neonate represents endogenous synthesis from the newborn and not derived from the mother. So CRP elevation is a reliable parameter differently from other biomarkers that, for their molecular structure, can cross the placenta barrier and give misleading results.8

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WBC and C-Reactive Protein (CRP)

Inflammation

In case of inflammation, which is the general mechanism induced by our body in response to an aggression, CRP values are raised and its analysis can be advantageous. CRP is an excellent marker of the acute inflammatory response and is used extensively for diagnosis and prognosis of rheumatologic and other diseases. CRP is routinely used to measure disease activity in rheumatoid arthritis. Similarly measuring CRP levels is helpful in monitoring disease course of various forms of vasculitis.9

CRP elevation in inflammatory bowel disease patients is associated with clinical disease activity, endoscopic inflammation, severely active histologic inflammation (in Crohn Diseases patients), and several other biomarkers of inflammation, but not with radiographic activity.10 Moreover in ulcerative colitis, a combination of the stool markers with the CRP and a disease-specific activity index can increase the diagnostic accuracy with reference to the endoscopic inflammation. According to these observations, CRP appears in the serum following inflammation induced by different etiologies and in response to a variety of stimuli related to disease biology.

Bacterial/viral infection

CRP concentration in plasma/serum shows a significant increase in various conditions like bacterial infections. This increase arrives very early following the stimulus and it is a sensitive indicator of most forms of microbial infection. CRP responses occur with more intensity in bacterial than in viral infection. The CRP level is widely used to detect bacterial infections in children with fever and in neonates with suspected sepsis. Key functions of CRP in the innate immune system include the ability to recognize and bind to phosphocholine exposed in damaged cell walls and found in many bacteria, fungi, and parasites. It acts like an opsonin, marking bacteria, damaged cell walls, and nuclear debris for phagocytosis. It binds to C1, the first component of the classical pathway of the complement system that triggers phagocytic activity; and bind to polymorphonuclear leukocytes (PMNs) and monocytes, which stimulate the production of inflammatory cytokines.

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WBC and C-Reactive Protein (CRP)

Urinary infections are a common type of pediatric disease, and their treatment and prognosis are closely correlated with infection location. Common clinical manifestations and laboratory tests are insufficient to differentiate between acute pyelonephritis (APN) and lower urinary tract infection (UTI). CRP can be used for upper and lower urinary tract infection differentiation. The serum CRP mean level of the APN (70mg/L) was significantly higher than the UTI (20mg/L). 11

CRP can be also used for example in the diagnosis of neonatal meningitis. The level is increased in most forms of acute and chronic inflammatory states including sepsis syndromes. CRP is, perhaps, the most widely used biomarker of infection in critically ill patients. Human Immunodeficiency Virus (HIV) infection has been frequently associated with chronic inflammation as well as depression. CRP is positively associated with depression in people with HIV infection (serum level of CRP>3mg/L).12

CRP concentration has useful prognostic value in patient with HIV associated to Tuberculosis (TB). High CRP values (≥50mg/L) were strongly associated with poor prognostic clinical features, higher mycobacterial load, and increased frequency of disseminated TB and higher risk of death.13 In particular in low respiratory tract infections (accounting for about 6.9% global mortality), differentiating viral from bacterial causes is important in order to decide about the pertinence of antibiotic therapy. The serum CRP concentration is almost 2-fold higher in acute bacterial infected patients than in acute viral infected patients (91.7mg/L versus 58.1mg/L.)14 Therefore CRP measure allows, first, starting the optimal treatment and second, preventing abuse of inappropriate antibiotic treatment and subsequent bacterial resistance.

Cancers

CRP has an important role in the tumor progression. Elevated CRP level has been previously associated with poor prognosis in several cancer type including small-scale studies in pancreatic cancer (PC) patients and hepatocellular carcinoma (HCC). Elevated serum CRP level is independently associated with a poor prognosis in HCC patients, and the addition of the CRP level to the validated staging systems could improve the prognostic ability of each staging system.15

Brain disorders

Early hematoma growth (EHG) occurs in about one third of patients with spontaneous intra-cerebral hemorrhage. CRP>10mg/L is independently predictive of EHG and ENW (early neurological worsening), both of which are associated with increased mortality. Inflammation may be important in contributing to EHG and warrants further investigation.16

Cardiovascular diseases

High sensitive CRP (hs-CRP): About 20 years ago highly sensitive assays were developed that could detect a light increase of CRP compared to baseline levels. These assays are said to measure high sensitivity CRP (hs-CRP) although the only difference is in the ability to detect lower range of CRP. This lower range of measurement may expand the indications for use to include the evaluation of conditions thought to be associated with inflammation in otherwise healthy individuals.

Increases in CRP using assays with expanded sensitivity to very low levels of CRP, so called hs-CRP demonstrated a strong correlation as an independent risk factor for future cardiac events. Thus, hs-

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WBC and C-Reactive Protein (CRP)

CRP values of <1,1mg/L to <3mg/L, and ≥3mg/L have been suggested to define low, moderate, and high-risk for cardiovascular events.17

Additionally, in acute coronary syndromes (ACS), increased CRP levels (CRP > 10mg/L) reflect the presence of “vulnerable” plaques at highest risk of acute thrombosis. Indeed, there is a correlation between CRP levels and the occurrence of major cardiac events; patients with elevated CRP levels have more rapid progression of existing high-risk lesions.18

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WBC and C-Reactive Protein (CRP)

Take-home messages

CRP level is increased in major way in acute phase responses. The acute phase response includes inflammatory disease, trauma, necrosis, malignancy, infections and allergic complications during infection and hypersensitivity.

Thus CRP is an important parameter in the medical world. It can be associated to other parameters in order to better establish the diagnosis or prognosis in several diseases in emergency medicine or pediatrics. Additionally this parameter, more specific for bacterial infections than viral infections, it can facilitate the decision to begin an anti-biotherapy or not.

CRP measurement is an excellent tool for use in monitoring infection profiles as its increased expression correlates with temperature fluctuations during fever. This allows a dynamic analysis of the infection progression and can consequently lead to more accurate and prompt administration of antibiotic treatment, or withdrawal of antibiotic therapy if required. Some laboratory routine tests such as CBC are fast, economical, and universally available, and often aid primary clinicians with decision making about patients with suspected bacterial infections. Thus the rapid availability of the results of CBC as well as CRP could provide considerable advantage for both patients and clinicians.

Inaba T. Microsemi LC-667CRP evaluation in perspective of influenza diagnosis, ISLH 2010

Source: Holland “National College of General Practitioners” Guidelines

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WBC and C-Reactive Protein (CRP)

As summarized by the following diagram, CRP level is different in several conditions in relation with 19 acute phase response. The acute phase response is a group of physiologic changes that occur shortly after the onset of an infection or other inflammatory process and includes an increase in the blood level of various proteins, especially C-reactive protein, fever, and other metabolic changes. 20

CRP IN ACUTE PHASE RESPONSE

CRP CRP

Infections Bacterial Systemic Severe fungal Mycobacterial Viral (low rise compared to bacterial rising) Allergic complications of infection Erythema nodosum Inflammatory disease Systemic lupus erythematosus Rheumatoid arthritis Scleroderma Ankylosing spondylitis Dermatomyositis Psoriatic arthritis Ulcerative colitis Crohn disease Leukemia Necrosis Graft-versus-host disease Myocardial infarction;Tumor embolization Acute pancreatitis Trauma Surgery Burns Fractures Malignancy Lymphoma Carcinoma Sarcoma

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Cited references

1. Macleod CM, Avery OT. The occurrence during acute infections of a protein not normally present in the blood immunological properties of the C - reactive protein and its differentiation from normal blood proteins. J Exp Med. 1941 Jan 31; 73(2):191-200. 2. Szalai AJ, Agrawal A, Greenhough TJ, Volanakis JE. C-reactive protein: structural biology, gene expression, and host defense function. Immunol Res. 1997; 16(2):127-36. 3. Gabay C, Kushner I. Mechanisms of disease: acute-phase proteins and other systemic responses to inflammation. N Engl J Med. 1999;340:448-454. 4. Henry’s, 22nd ed Chap 18,p254, 5. Clyne B, Olshaker JS. The C-reactive protein. J Emerg Med. 1999 Nov-Dec; 17(6):1019-25. Review 6. Mccarty m et al. The occurrence during acute infections of a protein not normally present in the blood. Crystallization of the C - reactive protein. J exp med. (1947) 7. Berger C, Uehlinger J, Ghelfi D, Blau N, Fanconi S. Comparison of C-reactive protein and white blood cell count with differential in neonates at risk for septicaemia. Eur J Pediatr. 1995 Feb; 154(2):138-44. 8. Kääpä P, Koistinen E. Maternal and neonatal C-reactive protein after interventions during delivery. Acta Obstet Gynecol Scand. 1993 Oct; 72(7):543-6. 9. Du Clos TW. Pentraxins: structure, function, and role in inflammation. ISRN Inflamm. 2013 Sep 14. 10. Langhorst J, Elsenbruch S, Koelzer J, Rueffer A, Michalsen A, Dobos GJ. Noninvasive markers in the assessment of intestinal inflammation in inflammatory bowel diseases: performance of fecal lactoferrin, calprotectin, and PMN-elastase, CRP, and clinical indices. Am J Gastroenterol. 2008 Jan;103(1):162-9. Epub 2007 Oct 4. 11. Xu RY1, Liu HW, Liu JL, Dong JH. Procalcitonin and C-reactive protein in urinary tract infection diagnosis. BMC Urol. 2014 May 30;14:45. doi: 10.1186/1471-2490-14-45. 12. Poudel-Tandukar K, Bertone-Johnson ER, Palmer PH, Poudel KC. C-reactive protein and depression in persons with Human Immunodeficiency Virus infection. Brain Behav Immun. 2014 Jun 11. 13. Lawn SD, Kerkhoff AD, Vogt M, Wood R. Diagnostic and prognostic value of serum C-reactive protein for screening for HIV-associated tuberculosis. Int J Tuberc Lung Dis. 2013 May 14. Ip M, Rainer TH, Lee N, Chan C, Chau SS, Leung W, Leung MF, Tam TK, Antonio GE, Lui G, Lau TK, Hui DS, Fuchs D, Renneberg R, Chan K.P. Value of serum procalcitonin, neopterin, and C- reactive protein in differentiating bacterial from viral etiologies in patients presenting with lower respiratory tract infections. Diagn Microbiol Infect Dis. 2007 Oct; 59(2):131-6. Epub 2007 Jul 26. 15. Kinoshita A, Onoda H, Imai N, Iwaku A, Oishi M, Tanaka K, Fushiya N, The Addition of C-Reactive Protein to Validated Staging Systems Improves Their Prognostic Ability in Patients with Hepatocellular Carcinoma. Oncology. 2014 Jun 7; 86(5-6):308-317. 16. Di Napoli M, Parry-Jones AR, Smith CJ, Hopkins SJ, Slevin M, Masotti L, Campi V, Singh P, Papa F, Popa-Wagner A, Tudorica V, Godoy DA. C-reactive protein predicts hematoma growth in intracerebral hemorrhage .Stroke. 2014 Jan; 45(1):59-65. 17. Pearson TA, Mensah GA, Alexander RW, et al. Markers of inflammation and cardiovascular disease: application to clinical and public health practice: a statement for healthcare professionals from the Centers for Disease Control and Prevention and the American Heart Association. Circulation. 2003; 107: 499–511. 18. Kelly CR, et al. Relation of C - reactive protein Levels to Instability of Untreated Vulnerable Coronary Plaques (from the PROSPECT Study). Am J Cardiol. 2014 Aug 1;114(3):376-83. 19. Pepys MB, Hirschfield GM. C-reactive protein: a critical update. J Clin Invest. 2003 Jun;111(12):1805-1 20. The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company

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More bibliography

Title Abstract and link Area This study aimed to evaluate the utility of CRP, PCT, D-lactate, and WBC count as an aid to distinguish appendicitis from other diagnoses. CRP with WBC is useful in distinguishing appendicitis from other diagnoses in pediatric subjects presenting to the Diagnosing pediatric appendicitis: ED. usefulness of laboratory markers. Kwan KY. Am J Emerg Med. 2010 WBC count greater than >12 cells × 1000/mm3 and CRP greater than 30mg/L increases

the likelihood of appendicitis. D-Lactate is not a useful laboratory adjunct. http://www.ncbi.nlm.nih.gov/pubmed/20825931

The measure of inflammatory biomarkers such as ESR, CRP and PCT is widely used for diagnostic and prognostic purposes in patients with fever or inflammatory syndromes.

NFLAMMATION Old and new inflammatory However, their true diagnostic accuracy and usefulness are not well known and are biomarkers: what utility for general probably overestimated. internist? Monti M. Rev Med Suisse. 2013 The purpose of this article is to summarize the current evidence about the accuracy and usefulness of these tests in different contexts of internal medicine. http://www.ncbi.nlm.nih.gov/pubmed/24313053

In this review, they focus their attention to the role of CRP in health and disease. The future prospect of this review lies in the applicability of CRP as a molecule in CRP and the biology of disease understanding and monitoring of the biology of disease. Ansar W. Immunol Res. 2013 http://www.ncbi.nlm.nih.gov/pubmed/23371836

PCT is widely used together with other biomarkers, such as WBC count and CRP, in Comparison between WBC,PCT and order to guide antibiotic therapy. This study aimed to verify the diagnostic and CRP as diagnostic and prognostic prognostic power of WBC, CRP and PCT in patients with suspected infection in biomarkers of infection or sepsis in emergency department (ED) patients presenting to emergency department CRP and PCT are reliable diagnostic and prognostic biomarkers, when considered in Magrini L. Clin Chem Lab Med.2014 combination and with severity clinical score. http://www.ncbi.nlm.nih.gov/pubmed/24803611

This study aimed to determine an optimal cut-off point of serum CRP levels for prediction of neonatal sepsis.

An optimal cut-off point of serum Serial CRP is safe as diagnostic tool to consider antimicrobial treatment in neonatal CRP in prediction of neonatal sepsis. sepsis with sensitivity of 92.6% and 96.3% for the first CRP cut-off point > or = Boonkasidecha S. J Med Assoc 1.90mg/L and the second CRP > or = 1.25mg/L with 100% positive predictive value. Thai. 2013 Moreover, these safety profiles might help in reducing overuse of antibiotics with negative predictive value 96.3%

INFECTION http://www.ncbi.nlm.nih.gov/pubmed/23724458

Here they show for the first time that CRP-deficient mice are remarkably susceptible to Streptococcus pneumoniae infection and are protected by reconstitution with isolated pure human CRP, or by anti-pneumococcal antibodies. CRP is essential for innate resistance to pneumococcal infection. Deficiency or loss of function variation in CRP may therefore be lethal at the first early- Simons JP. Immunology. 2014 life encounter with this ubiquitous virulent pathogen, explaining the invariant presence and structure of CRP in human adults. http://www.ncbi.nlm.nih.gov/pubmed/24673624

We aimed to examine whether CRP elevation precedes the clinical signs and symptoms Elevation of CRP precedes clinical of infection among patients undergoing allogeneic hematopoietic cell transplantation suspicion of bloodstream infections in (HCT). patients undergoing hematopoietic cell A daily increase of CRP blood levels of >40mg/L in afebrile HCT recipients should transplantation. trigger an evaluation for infection. Ram R. J Infect. 2013 http://www.ncbi.nlm.nih.gov/pubmed/23707844

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To assess the diagnostic and prognostic utility of CRP among patients being screened for TB before ART in a South African ART clinic. Diagnostic and prognostic value of CRP concentrations identified groups of patients with very high or very low TB risk, but serum CRP for screening for HIV- only in an unacceptably small minority of patients screened. However, in those with associated tuberculosis. confirmed TB, CRP concentrations had useful prognostic value. Lawn SD. Int J Tuberc Lung Dis. 2013 http://www.ncbi.nlm.nih.gov/pubmed/23575330

This study determined the serum levels of tumour necrosis factor alpha (TNF-α) and CRP as inflammatory markers in Nigerian SCA patients with and without parvovirus A study on the association between B19 infections. parvovirus B19 infection, serum

tumour necrosis factor and CRP levels We conclude that parvovirus B19 infection is common in this environment, and that among Nigerian patients with sickle serum TNF-α and CRP are predictors of clinical inflammatory episodes in infected cell anaemia Sickle Cell Anaemia patients Iwalokun BA. Singapore Med J. 2012 http://www.ncbi.nlm.nih.gov/pubmed/23192499

The neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio PLR and CRP levels CRP as predictor of recurrence in for 84 patients with rectal cancer undergoing CRT were available as indicators of patients with rectal cancer undergoing Systemic Inflammatory Response (SIR) status. The impact of SIR status on the prognosis chemoradiotherapy followed by of these patients was assessed. surgery. CRP is a promising predictor of recurrence and prognosis in patients with rectal cancer Toiyama Y. Anticancer Res. 2013 treated by CRT. http://www.ncbi.nlm.nih.gov/pubmed/24222151

They evaluated an inflammatory biomarker, CRP in predicting RT-induced EASRs in Inflammatory Biomarker CRP and 159 breast cancer patients undergoing RT. In each patient, they measured pre- and post- Radiotherapy-Induced Early Adverse RT plasma CRP levels using a highly-sensitive ELISA CRP assay. Skin Reactions in Breast Cancer Patients. This is the first study to demonstrate that an inflammatory biomarker CRP is associated Rodriguez-Gil JL. Cancer Epidemiol with RT-induced EASRs, particularly combined with obesity. Biomarkers Prev. 2014 http://www.ncbi.nlm.nih.gov/pubmed/24917184

To determine the concentration of CRP in pre- and post-operative serum samples of brain tumour patients in order to detect the potential risks of post-operative infections. Pre-operative serum CRP concentrations of 28% of the patients were elevated, Pre- and post-operative values of suggesting an association with brain tumours.

serum CRP in patients undergoing surgery for brain tumour Post-operative serum concentrations were significantly higher than those noted before the CER Syeda T. J Pak Med Assoc. 2014 surgery. Absence of a fall of concentration from peak value on post-operative Day 2 or a secondary rise from post-operative Day 7 could be alarming for inter-current infection. CAN http://www.ncbi.nlm.nih.gov/pubmed/24864598

This study aimed to determine CRP levels as diagnostic markers of infection in acute myeloid leukemia (AML) patients with neutropenia. CRP as a marker of the severity of an infectious process in acute myeloid CRP is a marker of the severity of an infectious process in AML patients with leukemia patients with neutropenia neutropenia. The increase of its level more than 32mg/L serves a valid criterion for the Vladimirova SG. Ter Arkh. 2013 presence of infection and more than 105mg/L does for that of a systemic inflammatory response in these patients http://www.ncbi.nlm.nih.gov/pubmed/24432597

The aim of this review is to summarize present evidence of an association between circulating levels of CRP and cancer risk, and to evaluate whether elevated circulating CRP levels cause cancer. Among individuals diagnosed with cancer during the study period, individuals with a Elevated CRP in the diagnosis, high baseline CRP (>3mg/L) had an 80% greater risk of early death compared with those prognosis, and cause of cancer. with low CRP levels (<1mg/L). Allin KH, Nordestgaard BG.Crit Rev Clin Lab Sci. 2011. Accordingly, patients with invasive breast cancer and CRP levels>3mg/L at diagnosis had a 1.7-fold increased risk of death from breast cancer compared to patients with CRP levels<1mg/L at diagnosis. http://www.ncbi.nlm.nih.gov/pubmed/22035340

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The purpose of this study was to assess the degree of elevation of serum CRP levels in infants with gastroschisis managed by placement of a preformed silo and subsequent CRP levels in babies with gastroschisis non-operative closure. managed with preformed silos. Elevation of serum CRP levels is to be expected in infants with gastroschisis managed Ram AD, Drewett M, Burge D. with a preformed silo in the absence of infection. This data may be used to prevent Eur J Pediatr Surg. 2013 unnecessary use of antibiotics in this group of patients. http://www.ncbi.nlm.nih.gov/pubmed/2352958.

CRP is widely used to detect bacterial infection in children. They investigated the impact of CRP test results on decision-making and summarized the evidence base (EB) of CRP testing. The routine ordering of CRP for children with infections is based on weak Impact of CRP test results on evidence. evidence-based decision-making in The impact of the CRP test results on decision-making is rather small, and CRP ordering cases of bacterial infection. may contribute to unnecessary health care expenditures. Better quality research is needed Nabulsi M, Hani A, Karam M. to definitively determine the diagnostic accuracy of CRP levels in children with BMC Pediatr. 2012 infections. http://www.ncbi.nlm.nih.gov/pubmed/22943554

This study aimed to evaluate the diagnostic performance of maternal inflammatory PEDRIATRY marker: CRP in predicting early onset neonatal sepsis (that occurring within 72 hours after birth). Positive maternal CRP predicts neonatal sepsis The risk of early onset neonatal sepsis significantly increased in the case of positive Jeon JH. Yonsei Med J. 2014 maternal CRP (≥12.2mg/L). In newborn of CRP positive mother, the clinician may be alerted to earlier evaluation for possible neonatal infection prior to development of sepsis. http://www.ncbi.nlm.nih.gov/pubmed/24339295

This study aimed to evaluate the usefulness of a single CRP measurement at 18 h of age to identify neonates where antibiotics started for possible early onset sepsis (EOS) could safely be discontinued. Value of a single CRP measurement at 18 h of age. The duration of antibiotic treatment in neonates born beyond 34 weeks' gestation and Lacaze-Masmonteil T. Arch Dis Child asymptomatic at the time of CRP assessment could be potentially reduced with a Fetal Neonatal Ed. 2014 diagnostic algorithm that includes a point-of-care 18-h CRP measurement. The current study shows that a CRP measured at approximately 18 h of life has a sensitivity of only 64% for detecting combined possible and proven EOS. http://www.ncbi.nlm.nih.gov/pubmed/24008814

Heatstroke (HS) is a life-threatening condition, manifested by systemic inflammation and multiorgan failure. Rapid recognition and treatment are lifesaving. The report a laboratory-oriented characterization of HS by low plasma CRP level and propose its

Low plasma CRP level as an early usefulness in distinguishing this type of hyperpyrexia from central nervous system- diagnostic tool for heatstroke vs associated high core temperature. central nervous system-associated infection in the ED. Low serum CRP levels characterize non-central nervous system-associated HS. This Dahan E. Am J Emerg Med. 2013 available laboratory test could identify noninfectious hyperthermic patients upon

SIVECARE admission, saving precious time until treatment and avoiding unnecessary diagnostic tests. http://www.ncbi.nlm.nih.gov/pubmed/23726745

Diagnosis of sepsis in the postoperative period is a challenge. Measurements of inflammatory markers, such as CRP, have been proposed in medical patients, but the interpretation of these values in surgical patients is more difficult. They evaluated the changes in blood CRP levels and white blood cell count in postoperative patients with CRP Kinetics after Major Surgery. and without infection. Santonocito C. Anesth Analg. 2014 May EMERGENCY& INTEN 29 CRP levels increase in the first week after major surgery but to a much larger extent in infected than in non-infected patients. Persistently high CRP levels after postoperative day 4, especially when >100 mg/L, suggest the presence of a postoperative infection. http://www.ncbi.nlm.nih.gov/pubmed/24878684

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Mortality is high among patients admitted to intensive care units (ICUs). Several prognostic markers have been described in such patients, but the literature contains no CRP alone or combined with cardiac data comparing CRP and cardiac troponin T (cTn-T), nor of a combination of CRP and troponin T for risk stratification of cTn-T in the same patient group in the ICU. respiratory intensive care unit

patients. Elevated CRP is an independent early prognostic marker of mortality risk in ICU Ozsu S. Respir Care. 2011 patients. We suspect that a CRP-based prognosis strategy may be useful. http://www.ncbi.nlm.nih.gov/pubmed/21352664

Baseline CRP levels predict major adverse cardiovascular events (MACE: death, C-reactive protein, but not low-density myocardial infarction, stroke, coronary revascularization, and hospitalization for unstable lipoprotein cholesterol levels, angina). The association between changes in CRP levels with plaque progression and associates with coronary atheroma MACE in the setting of maximally intensive statin therapy is unknown. regression and cardiovascular events after maximally intensive statin Following 24 months of potent statin therapy, on-treatment CRP levels associated with therapy. MACE. Inflammation may be an important driver of residual cardiovascular risk in

Puri R. Circulation. 2013 Nov patients with coronary artery disease despite aggressive statin therapy. 26;128(22):2395-403. http://www.ncbi.nlm.nih.gov/pubmed/24043299

In this analysis from the PROSPECT study, the hypothesized that patients with elevated

CARDIOLOGY CRP levels would have a greater burden and/ or more rapid progression of these high- risk lesions, which could explain their heightened risk for Major adverse cardiac events Relation of CRP Levels to Instability (MACE) of Untreated Vulnerable Coronary

Plaques (from the PROSPECT Study). In conclusion, the higher rates of non-culprit lesions ( NCL)-related MACE in post-acute Kelly CR. Am J Cardiol. 2014 coronary syndrome patients with very elevated CRP levels may reflect greater instability of high-risk untreated NCLs, rather than a larger burden of such lesions. http://www.ncbi.nlm.nih.gov/pubmed/24931291

They conducted a retrospective, matched, case-control study in patients with P. mirabilis bacteremic UTIs. The aims of our study were to (1) determinate the relative risk factors of P. mirabilis bacteremic UTIs, (2) investigate the risk factors related to mortality, and Proteus mirabilis urinary tract (3) compare the resistance profiles of P. mirabilis between these two groups of patients. infection and bacteremia: risk factors, clinical presentation, and outcomes. Because bacteremic P. mirabilis UTIs are associated with higher mortality, clinicians Chen CY. J Microbiol Immunol should carefully manage cases that present with the risk factors for bacteremia, including Infect. 2012 Jun;45(3):228-36. community-acquired infection, hydronephrosis, band neutrophils accounting for >10% of the white blood cell count, hyperthermia or hypothermia, and a high level of CRP http://www.ncbi.nlm.nih.gov/pubmed/22572004

This study aimed to investigate the role of serum CRP levels in women with lower urinary tract symptoms (LUTS). The role of serum C-reactive protein

in women with lower urinary tract High serum CRP levels were found in women with overactive bladder (OAB) wet, and symptoms. they were related to lower maximum urinary flow rates and higher body mass indices in URINARYTRACT INFECTION Hsiao SM. Int Urogynecol J. 2012 non-non-stress urinary incontinence (non-SUI) LUTD. However, serum CRP is not a Jul;23(7):935-40 suitable biomarker for discriminating between subtypes of non-SUI LUTD.

http://www.ncbi.nlm.nih.gov/pubmed/22422219

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