C-reactive protein

Reference values ​​of the concentration of C-reactive protein( CRP) in serum - less than 5 mg / l.

CRP is a protein consisting of 5 identical, non-covalently linked ring subunits. CRP is determined in the blood serum for various inflammatory and necrotic processes and is an indicator of the acute phase of their course. Its name was obtained because of its ability to precipitate the C-polysaccharide of the cell wall of pneumococcus. Synthesis of CRP as an acute phase protein occurs in the liver under the influence of IL-6 and other cytokines.

CRP enhances the motility of leukocytes. By binding to T-lymphocytes, it affects their functional activity by initiating precipitation, agglutination, phagocytosis, and complement binding. In the presence of calcium, CRP binds ligands in polysaccharides of microorganisms and causes their elimination.

Increase in the concentration of CRP in the blood begins within the first 4 hours from the moment of tissue damage, reaches a maximum after 24-72 hours and decreases during convalescence. Increasing the concentration of CRP is the earliest sign of infection, and effective therapy is manifested by its decrease. CRP reflects the intensity of the inflammatory process, and monitoring it is important for monitoring these diseases. The content of CRP during inflammatory process can be increased 20 times or more. Concentration of CRP in the serum above 80-100 mg / l indicates a bacterial infection or systemic vasculitis. With active rheumatoid

, the increase in CRP is found in most patients. In parallel with a decrease in the activity of the rheumatic process, the content of CRP decreases. A positive reaction in the inactive phase may be due to focal infection( chronic tonsillitis).

Rheumatoid arthritis is also accompanied by an increase in CRP( a marker of process activity), however its determination can not help in the differential diagnosis between rheumatoid arthritis and rheumatic polyarthritis. The concentration of CRP is directly related to the activity of ankylosing spondylitis. In SLE( especially in the absence of serositis), the concentration of CRP is usually not increased.

With IM, CRB rises after 18-36 h after the onset of the disease, decreases by the 18-20th day and comes to normal by the 30-40th day. High levels of CRP in infarction( as well as with acute impairment of cerebral circulation) are prognostically unfavorable signs. With angina pectoris, it remains within normal limits. CRP should be considered as an indicator of active atheromatosis and thrombotic complications in patients with unstable angina.

With edematic pancreatitis, the concentration of CRP is usually normal, but it rises significantly in all forms of pancreatic necrosis. It was found that CRP values ​​above 150 mg / l indicate severe( pancreatic necrosis) or complicated acute pancreatitis. The study of CRP is important for determining the prognosis of acute pancreatitis. The predictive value of positive and negative CRP results for the determination of an unfavorable prognosis of acute pancreatitis at a separation point of more than 100 mg / l is 73%.

After surgical interventions, the concentration of CRP increases in the early postoperative period, but begins to decline rapidly in the absence of infectious complications.

Synthesis of CRP is enhanced in tumors of various localizations. An increase in the concentration of CRP in the blood is noted with cancer of the lung, prostate, stomach, ovaries and other tumors. Despite its nonspecificity, CRB, together with other cancer markers, can serve as a test for evaluating tumor progression and relapse.

There is a strong correlation between the degree of enhancement of CRP and ESR, however, CRP appears and disappears earlier than changes in ESR.

Increased concentration of CRP is characteristic of rheumatism, acute bacterial, fungal, parasitic and viral infections, endocarditis, rheumatoid arthritis, tuberculosis, peritonitis, MI, conditions after severe operations, malignant tumors with metastases, multiple myeloma.

The level of CRP does not increase significantly with viral and spirochete infections. Therefore, in the absence of trauma, very high CRP values ​​in most cases indicate a bacterial infection.

When interpreting the results of determining the concentration of CRP it is necessary to take into account that for virus infections, metastases of malignant tumors, slow chronic and a number of rheumatic diseases, an increase in the level of CRP to 10-30 mg / l is characteristic. Bacterial infections, exacerbation of certain rheumatic diseases( for example, rheumatoid arthritis) and tissue damage( surgical operation, MI)

are accompanied by an increase in the concentration of CRP to 40-100 mg / l( sometimes up to 200 mg / l), and severe generalized infections, burns,sepsis - up to 300 mg / l and more.

The determination of serum level of serum CRP can serve as one of the criteria for establishing indications and stopping antibiotic treatment. The level of CRP below 10 mg / l indicates no infection and there is no need for antibiotic treatment.

C-reactive protein, ultrasensitive in the blood serum

For a long time, it was considered that the increase in the concentration of CRP above 5 mg / l was clinically significant; at the values ​​below this value, the absence of a systemic inflammatory response was ascertained. Later it was shown that the values ​​of the concentration of CRP exceeding 3 mg / l are an unfavorable prognostic sign associated with the risk of vascular complications in practically healthy people and patients with cardiovascular diseases. In this connection, ultrasensitive test systems and reagent kits were developed, based on the modification of immunoturbidimetric and immunonephilometric methods with AT immobilization on latex particles. These methods have approximately 10 times greater analytical sensitivity than traditional ones and allow us to record minimum fluctuations in the concentration of CRP in the blood even within the "traditional" reference values.