Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors
Search in posts
Search in pages
Filter by Categories
Case Report
Case Series
Chairman's Message
Director’s Message
Editorial
Original Article
ORIGINAL RESEARCH
Review Article
Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors
Search in posts
Search in pages
Filter by Categories
Case Report
Case Series
Chairman's Message
Director’s Message
Editorial
Original Article
ORIGINAL RESEARCH
Review Article
View/Download PDF

Translate this page into:

Review Article
2 (
2
); 106-108
doi:
10.25259/DJIGIMS_2_2023

C-Reactive Protein: Significance of a Non-Specific Biomarker: A Review

Department of Oral Medicine & Radiology, Sardar Patel Postgraduate Institute of Dental & Medical Sciences, Lucknow, Uttar Pradesh, India
Department of Oral Medicine & Radiology, Nil Ratan Sircar Medical College & Hospital, Sealdah, Kolkata, India
Corresponding author: Dr. Sonalika Srivastava, Department of Oral Medicine & Radiology, Sardar Patel Postgraduate Institute of Dental & Medical Sciences, Lucknow, Uttar Pradesh, India. dr.sonalikasrivastava@gmail.com
Licence
This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.

How to cite this article: Srivastava S, Sinha A, Mishra A, Giri D, Sinha P. C-Reactive Protein: Significance of a Non-Specific Biomarker: A Review. Dent J Indira Gandhi Inst Med Sci. 2023;2:106–8. doi: 10.25259/DJIGIMS_2_2023.

Abstract

C-reactive protein (CRP) is a non-specific acute phase reactant that increases in response to infection or inflammation. Higher levels suggest a more severe infection and have been used to predict the severity of COVID-19 disease. CRP, an acute phase protein, is one of several downstream indicators of inflammation. CRP improves cell-mediated immunity by increasing phagocytosis, hastening chemotaxis, and activating platelets. Here, in this review, we will discuss more about historical background, pathophysiology involved, normal ranges and interpretation of raised levels and significance of CRP in various pathologies. This will further enhance our knowledge related to clinical significance of CRP in day-to-day practice.

Keywords

Atherosclerosis
Cancer
Cardiovascular Disease
COVID-19
C-Reactive Protein

INTRODUCTION

C-reactive protein (CRP) responds to infection or inflammation and was found while investigating Streptococcus pneumoniae patients.[1,2] It plays a vital role in inflammation and increases cell-mediated immunity by accelerating phagocytosis and chemotaxis, and activates platelets.[3]

Historical background

CRP was discovered by Tillet and Francis as it has the capacity to precipitate and interact with phosphorylcholine residues of the C polysaccharide that is produced from teichoic acid within the cell wall of Streptococcus pneumoniae. It plays a significant role in innate immunity and its level rises in inflammatory diseases such as rheumatoid arthritis, cancer and cardiovascular disease.[4]

Pathophysiology of CRP

CRP, like serum amyloid P (SAP) component, has undergone extensive evolutionary conservation.[5] Pentraxins have an unusual structure having five non-glycosylated globular components arranged in a symmetrical cyclic pattern, resulting in a pentameric, discoidal and flattened form.[6] It is formed by liver during proinflammatory cytokine activity.[7] It increases de novo CRP production by upregulating Deoxyribonucleic acid (DNA) damage-inducible transcript 3 cytosine-cytosine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding proteins (C/EBP) that are critical transcription factors in this pathway.[8,9] It is seen in adipocytes cell indicating that obesity and chronic inflammation are related in yet another way.[10,11]

Interpretation of levels of CRP

Less than 0.3 mg/L: Normal

0.3 to 1.0 mg/L: Minor rise

1.0 to 10.0 mg/L: Moderate rise

More than 10.0 mg/L: Marked rise

More than 50.0 mg/L: Severe rise.[12]

Significance in various pathologies

  • In systemic lupus erythematosus

    During active disease, many persons with active systemic lupus erythematosus (SLE) have CRP values that are just slightly elevated or even normal. A large increase in level in an SLE patient indicates the presence of many concurrent infections.[13]

  • In diabetes:

    Increased levels can predict the onset of diabetes, and it was observed in research, conducted in an American Indian population having diabetes that CRP elevations were seen in cardiovascular disease in non-diabetic women, but it was not seen in diabetic women or men, indicating that the CRP elevations can act as a predictive marker for diabetes.[14]

  • In cancer:

    Assessment of its level during cancer can guide the doctor to evaluate the severity of the disease and can act as a reference in deciding the treatment and thus overall survival can be improved. It can also indicate the aggressiveness of the tumor in the body.[15]

  • In inflammation:

    It is largely present at sites where inflammation or injury has occured.[16] CRP localisation in neutrophil infiltrates has been linked to vasculitis and allergic encephalomyelitis lesions.[17]

  • In infection:

    It is an inflammatory marker that rises in bacterial infection,[18] and it has the ability to fight infection.[19]

  • In COVID-19:

    The excessive inflammation seen in COVID-19 patients is the primary cause for increased mortality and disease progression. During acute inflammation, severe insults or coronary heart disease, serum CRP levels are clearly raised. As the inflammation goes away, it becomes normal. It has the ability to enhance phagocytosis via a specific CRP receptor and destroy a wide range of pathogenic microorganisms.[20]

  • In chronic periodontitis:

    According to some experts, periodontal diseases are induced by the interaction of particular gram-negative bacterial species with the host defense in disease-sensitive individuals. The host responds to the microbial challenge with a significant inflammatory response that includes increased levels of inflammatory mediators. These mediators enhance acute phase reactant activation, resulting in elevated serum levels of CRP.

CONCLUSION

CRP appears to be more than just a marker of inflammation or infection; it appears to be a crucial regulator of inflammatory processes. More study is required to expand on these unique findings and completely understand the particular functions that each CRP variation plays at locations of local inflammation and infection.

Declaration of patients consent

Patient’s consent not required as there are no patients in this study.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

Use of Artificial Intelligence (AI)-Assisted Technology for manuscript preparation

The authors confirm that there was no use of Artificial Intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.

References

  1. , . Serological reactions in pneumonia with a non-protein somatic fraction of pneumococcus. J Exp Med. 1930;52:561-71.
    [CrossRef] [PubMed] [Google Scholar]
  2. , , , , . A review of C-reactive protein: A diagnostic indicator in periodontal medicine. J Pharm Bioallied Sci. 2012;4:S422-6.
    [CrossRef] [PubMed] [PubMed Central] [Google Scholar]
  3. , , . C-reactive protein. J Biol Chem. 2004;279:48487-90.
    [CrossRef] [PubMed] [Google Scholar]
  4. , , , , , . C-reactive protein, inflammatory conditions, and cardiovascular disease risk. Am J Med. 2007;120:1054-62.
    [CrossRef] [PubMed] [PubMed Central] [Google Scholar]
  5. , , , . Pentraxins in innate immunity: From C-reactive protein to the long pentraxin PTX3. J Clin Immunol. 2008;28:1-13.
    [CrossRef] [PubMed] [Google Scholar]
  6. , , . The physiological structure of human C-reactive protein and its complex with phosphocholine. Structure. 1999;7:169-77.
    [CrossRef] [PubMed] [Google Scholar]
  7. , , , . Proteína C reactiva y enfermedad arterial coronaria. Revista Cubana de Cardiología y Cirugía Cardiovascular. 2011;17:69-79.
    [PubMed] [Google Scholar]
  8. , , . C-reactive protein. J Biol Chem. 2004;279:48487-90.
    [CrossRef] [PubMed] [Google Scholar]
  9. , , . Impact of C-reactive protein on disease risk and its relation to dietary factors: Literature review. Asian Pac J Cancer Prev. 2007;8:167-77.
    [PubMed] [Google Scholar]
  10. , , . Relation of C-reactive protein to abdominal adiposity. Am J Cardiol. 2010;106:56-61.
    [CrossRef] [PubMed] [Google Scholar]
  11. , , , . Release of C-reactive protein in response to inflammatory cytokines by human adipocytes: linking obesity to vascular inflammation. J Am Coll Cardiol. 2005;46:1112-13.
    [CrossRef] [PubMed] [Google Scholar]
  12. , , . C Reactive Protein. Treasure Island (FL): StatPearls Publishing; .
  13. , , , , . C-reactive protein levels during disease exacerbations and infections in systemic lupus erythematosus: A prospective longitudinal study. J Rheumatol. 1990;17:1642-8.
    [PubMed] [Google Scholar]
  14. , , , . C-reactive protein and glycemic control in adults with diabetes. Diabetes Care. 2003;26:1535-9.
    [CrossRef] [PubMed] [Google Scholar]
  15. , , , . Elevated pretreatment levels of plasma C-reactive protein are associated with poor prognosis after breast cancer: A cohort study. Breast Cancer Res. 2011;13:55.
    [CrossRef] [PubMed] [Google Scholar]
  16. , , . Metabolic and scintigraphic studies of radioiodinated human C-reactive protein in health and disease. J Clin Invest. 1993;91:1351-7.
    [CrossRef] [PubMed] [Google Scholar]
  17. , , , , . Localization of C-reactive protein in inflammatory lesions of experimental allergic encephalomyelitis. Clin Exp Immunol. 1981;43:565-73.
    [PubMed] [PubMed Central] [Google Scholar]
  18. , . Infections. Br Med J. 2006;332:838-41.
    [Google Scholar]
  19. , , , , . C-reactive protein is protective against Streptococcus pneumoniae infection in mice. J Exp Med. 1981;154:1703-8.
    [CrossRef] [PubMed] [Google Scholar]
  20. , , . Update Advances on C-reactive protein in COVID-19 and other viral infections. Front Immunol. 2021;12:720363.
    [CrossRef] [PubMed] [PubMed Central] [Google Scholar]
Show Sections