What is the Difference Between CRP and hs-CRP

The key difference between CRP and hs-CRP is that CRP is a test for CRP protein performed when a patient has symptoms of infection or inflammation, while hs-CRP is a test for CRP protein performed when a person is metabolically stable without having symptoms of infection or inflammation.

C-reactive protein (CRP) is a protein found in blood plasma. The circulating concentrations of this protein rise normally in response to inflammation. CRP and hs-CRP are two tests that are performed to measure the C-reactive protein (CRP) in the blood. Though these two methods measure the same protein, they are used to diagnose different conditions.

CONTENTS

1. Overview and Key Difference
2. What is CRP 
3. What is hs-CRP
4. Similarities – CRP and hs-CRP
5. CRP vs. hs-CRP in Tabular Form
6. Summary – CRP vs. hs-CRP

What is CRP?

CRP test is performed to evaluate the CRP protein level in patients with symptoms of a severe bacterial infection or a serious chronic inflammatory disease. This test measures the CRP level in the range of up to 1000 mg/L. CRP test is usually better than erythrocyte sedimentation rate (ESR) and leukocyte count. Moreover, CRP tests help to diagnose or rule out certain medical conditions such as severe bacterial infections like sepsis, fungal infections, osteomyelitis, inflammatory bowel disease (IBD), some forms of arthritis, and autoimmune diseases such as rheumatoid arthritis or lupus (systemic lupus erythematosus) and pelvic inflammatory disease (PID).

Up to 6 mg/L CRP levels in the blood are considered normal. However, there will be minor elevation of this level due to cigarette smoking, common cold, depression, diabetes, insomnia, gingivitis, obesity, periodontitis, pregnancy, and recent injury. The level of CRP is moderately elevated in conditions like rheumatoid arthritis, systemic lupus erythematosus (SLE), other autoimmune conditions, heart attack, pancreatitis, and bronchitis. The marked elevation of CRP can be due to acute bacterial infections, viral infections, systemic vasculitis, and major injury (trauma). Furthermore, risks that are associated with CRP tests may include slight tenderness or a bruise at the site of the blood draw.

What is hs-CRP?

Hs-CRP is known as an ultra-high sensitivity CRP test. It measures minimal amounts of CRP in the blood. This is a test for CRP protein performed when a person is metabolically stable without showing any symptoms of infection or inflammation. Therefore, hs-CRP is normally ordered for apparently healthy people to determine the potential risk of cardiovascular disease. This test measures CRP levels in the range from 0.5 to 10 mg/L.

According to the American Heart Association (AHA), individuals with high hs-CRP levels have twice the risk of experiencing a cardiac arrest. Therefore, hs-CRP is an important risk assessment for cardiovascular diseases for men and women over the age of 50. Moreover, hs-CRP levels of less than 1.0 mg/L suggest no underlying health complications; between 1.0 mg/L to 3.0 mg/L suggests underlying inflammation and CVD complications; above 3.0 mg/L indicates CAD (coronary artery disease) issues and chronic illness. Hs-CRP predicts conditions such as myocardial infarction, stroke, peripheral vascular disease, and sudden cardiac death. Furthermore, risks that are associated with this test may include slight pain or bruising at the spot where the needle was put in.

What are the Similarities Between CRP and hs-CRP?

• CRP and hs-CRP are two tests that are performed to measure CRP in the blood.
• Both tests are blood tests.
• Phlebotomists perform them.
• Both tests have minor associated risks or side effects.
• Both tests are cheap tests.

What is the Difference Between CRP and hs-CRP?

CRP is a test for CRP protein performed when a patient has symptoms of infection or inflammation, while hs-CRP is a test for CRP protein performed when a person is metabolically stable and does not show symptoms of infection or inflammation. Thus, this is the key difference between CRP and hs-CRP. Furthermore, CRP is a more popular test than hs-CRP. However, hs-CRP tests are more sensitive than CRP tests.

The infographic below presents the differences between CRP and hs-CRP in tabular form for side-by-side comparison.

Summary – CRP vs. hs-CRP

CRP and hs-CRP are two tests that measure C-reactive protein (CRP) in the blood. CRP test is done when a patient has symptoms of infection or inflammation. In contrast, the hs-CRP test is done when a person is metabolically stable and does not show any symptoms of infection or inflammation. Moreover, CRP measures CRP levels in the range of up to 1000 mg/L in the blood, whereas hs-CRP measures CRP levels in the range from 0.5 to 10 mg/L in the blood. So, this summarizes the difference between CRP and hs-CRP.

Reference:

1. “C-Reactive Protein (CRP) Test: Medlineplus Medical Test.” MedlinePlus, U.S. National Library of Medicine.
2. “HS-CRP Test (C-Reactive Protein High-Sensitivity).” Testing.Com.

Image Courtesy:

1. “1lj7” By Ramadan, M.A., Shrive, A.K., Holden, D., Myles, D.A., Volanakis, J.E., DeLucas, L.J., Greenhough, T.J.; visualization author: User:Astrojan – RCSB (CC BY 3.0) via Commons Wikimedia