C-Reactive Protein (CRP)

CRP CRP is a serologic test which is used for diagnosis of Inflammations and Infections. CRP was so named because it was first identified as a substance in the serum of patients with acute inflammation that reacted with the C- Polysaccharide of Pneumococcus.

CRP CRP is a Protein found in the serum, which it’s levels rise in response to Inflammation. CRP is an Acute-Phase protein. Its physiological role is to bind to Phosphocoline expressed on the surface of dead or dying cells (and some types of bacteria) for Opsonization and activation of the Complement.

Acute phase response & proteins Inflammations, Infections, Trauma, MI, malignancy, some chronic diseases, operation… induce a systemic inflammation response that appear early, so it’s called Acute-phase response. Acute- Phase response accompanied with increase in synthesis of some proteins in Liver, which are called Acute-Phase proteins.

Proteins: CRP, SAA (>100 times), Haptoglobin, Fibrinogen, Ceruloplasmin (>fewtimes). Liver increase production of these proteins in response to IL-1, TNF and IL-6 produced by MΦ.

CRP Structure Pentraxin 5 protomer (23kDa,206 aa) Central pore

CRP CRP is an Important protein, because increase in it’s concentration is an indicator of Inflammation or infection. It’s level increases early (8-12 hrs), and after resolution of infection or inflammation decreases rapidly. It’s concentration increases up to 3000 times.

CRP Reference range < 8.0 mg/L Acute inflammation Greater than 10 mg/L Viral infection (10 to 40 mg/L) Bacterial infection (40 to > 200 mg/L) Cardiac risk stratification Low risk: < 1.0 mg/L Average risk: 1.0 to 3.0 mg/L High risk: > 3.0 mg/L

CRP Test  CRP is a rapid & simple agglutination test, which is done on an slide.  The type of reaction is: Passive reveres agglutination.

Rheumatoid Factor (RF)

RF RF Test is a serologic test for diagnosis of Rheumatoid arthritis (RA). RA is a chronic inflammatory autoimmune disease that mostly affect small joint of hands and foots. More common in women than men. Known as an autoimmune disease because the body’s immune system attacks the joint lining.

RF RFs are human auto-Abs that react with the Fc portion of normal polyclonal IgG. Named thus because their first description was in patients with rheumatoid arthritis. RF can be find in serum of 60-88% of RA patients.

RF Most routine clinical assays for RF detect only IgM RFs, although RFs can be any class of immunoglobulin. RF test is approximately 65%-75% sensitive for the diagnosis. The presence of RF, even in high titers or large amounts, is not specific for RA.

Conditions Associated with for RF positive Rheumatologic Diseases Lung Diseases Rheumatoid arthritis (~70%) Interstitial fibrosis Sjögren’s syndrome (~90%) Silicosis Lupus (~20%) Cryoglobulinemia syndrome (90%) Infections Miscellaneous Hepatitis C virus Sarcoidosis Acute viral infections Malignancies Endocarditis Aging Tuberculosis

RF Test  RF is a rapid and simple test look like CRP  RF is mostly done on slide and the results are writing as 1+ to 4+  Type of reaction is: Passive agglutination.