Ultrasensitive C-reactive protein (CRP) is an element of the acute phase and an indicator of tissue damage during inflammation, trauma and necrosis. It serves as a marker in the presence of various inflammatory processes. It is absent in the blood serum of a healthy person.
What is SBR?
Ultrasensitive C-reactive protein was first described in the last century as an element that showed, in the presence of calcium ions, the process of binding to pneumococcal polysaccharides, which is found only in patients with acute disease. In this regard, scientists have made a cautious assumption that this protein is able to participate in inflammatory processes.
At that time, it was difficult to imagine what role would be assigned to this element of blood in medicine and, in particular, in the framework of clinical laboratory diagnostics. Next, we find out when the element in question does not correspond to the norm.
Reasons for rejection
Against the background of injuries, infections, inflammations, the level of C-reactive ultra-sensitive protein rises sharply a hundred times or more. The concentration of this element in the blood has high correlations with the activity of the pathology and the stage of the process. When C-reactive ultra-sensitive protein is elevated, this is a sign of acute inflammation in rheumatic ailments, tuberculosis, necrosis, and malignant neoplasms.
The most significant increase is observed with bacterial infections, against the background of this, the concentration can reach more than 100 mg / l. With a viral and fungal infection, on average it is 30 mg / l of blood. A decrease in the concentration of CRP during therapy is usually indicative of the effectiveness of the treatment.
CRP and ESR
Tests conducted by the method for C-reactive ultra-sensitive protein are most often compared with the erythrocyte sedimentation rate. Both of these values increase sharply at the onset of the disease, but the protein appears and disappears earlier than the ESR changes. With successful therapy, the level of CRP decreases over the next day, normalizing by 6-10 days, while the sedimentation rate decreases only after 2-4 weeks.
The rapid normalization of CRP makes it possible to use the analysis to monitor the progress of the disease and monitor the effectiveness of treatment. In any disease, or after surgery, the attachment of bacterial infections, whether local processes or sepsis, is usually accompanied by an increase in the level of the acute phase protein.
CRP indicators
In the absence of obvious reasons, a slight increase in C-reactive ultra-sensitive protein indicates subclinical chronic inflammation of the vascular walls. This can serve as a factor in cardiac and vascular catastrophe. For example, we can talk about atherosclerosis, heart attack, thromboembolism and stroke. Highly sensitive CRP determination methods make it possible to establish its concentration of less than 5 mg / L. Initial concentrations of less than 1 mg correspond to a low value, from 1 to 3 - to an average, and when a higher indicator is noted, then they speak of high cardiovascular risk.
The information content of the protein index, which is determined by highly sensitive methods, is much higher compared to the calculation of low density cholesterol lipoproteins. The risks of cardiac and vascular complications among patients with an increase in CRP increase in combination with simultaneously high values of cholesterol, fibrinogen, homocysteine, and so on.
What methods are used to determine C-reactive ultra-sensitive CRP protein?
Determination methods
Today, classical methods for determining the concentration of CRP in the blood plasma are radial immunodiffusion along with immunoturbidimetry and nephelometry.
In clinical practice, this protein is considered as the main, although quite a non-specific marker of inflammation. It belongs to the so-called acute phase elements that can appear in the blood in response to some tissue damage to the body that is caused by infection, inflammation, tumor growth, injuries and other factors.
CRP is classified as a protein of a strong subgroup, since its content in human blood can increase several thousand times, in contrast to the weak elements of the acute phase. In addition, the time of appearance of the protein is from 6 to 12 hours, while the elements of the weak subgroup can be determined in the blood only after 48-72 hours.
This makes it a very effective marker, especially if we talk about the time of detection of pathologies. Now we find out what should be the norm value of this protein in the analysis of patients.
Normal and negative values
As a rule, in healthy people, the content of C-reactive ultra-sensitive protein (CRP) is less than 5 mg / L. In the presence of diseases, the concentration of CRP is within a huge range (it is approximately from 0.05 to 500 mg). In medicine, several levels of the described protein in the blood are distinguished:
- A negative value is noted when CRP is up to 3 mg.
- A weakly positive result is established at values from 3 to 6 mg.
- A positive indicator is indicated in the presence of protein in the range of 6-12 mg.
- CRP is sharply positive from 12.0 mg and above. The rate of C-reactive ultra-sensitive protein should be determined by a highly qualified specialist.
The highest levels of CRP (over 30) are observed in the presence of a bacterial infection, such as septic arthritis, meningitis and pneumonia. With a viral infection, the level of this element is much lower, which makes it possible to use quantitative analyzes to differentiate the two infections. Moderately high concentrations of CRP - approximately 10 to 40 mg are found in patients who have suffered myocardial infarction and suffer from other tissue injuries.
Diagnostic protein research
C-reactive protein is used to diagnose inflammation along with criteria such as erythrocyte sedimentation rate. However, research on the determination of protein, as noted earlier, allows you to establish inflammation much earlier, since its level increases before the ESR changes.
An increase in the content of this protein in the blood is observed not only with inflammation of bacterial or viral origin, but also in the case of any tissue damage, including necrosis, tumor and parasitic infection, which significantly expands its use in the diagnosis. In addition, due to the wide range of indicators and correlation with the ESR value, it is possible to carry out a relatively accurate differentiation of the type of disease.
When is CRP analysis required?
Such a study is advisable in the following cases:
- In the framework of determining the reactivity of pathological processes and the effectiveness of treatment.
- In acute infectious diseases.
- In the case of the development of a tumor or suspicion of such.
- As part of monitoring the effectiveness of the treatment of chronic diseases (for example, with amyloidosis).
- Against the background of monitoring the effectiveness of antibacterial treatment (with sepsis of newborns, meningitis).
- In order to determine the risk of heart and vascular complications among patients with atherosclerosis or diabetes, as well as those who are on chronic hemodialysis.
If the level of C-reactive ultra-sensitive protein is increased, it is important to find out the reasons.
What is the increase in CRP?
An increase in this indicator informs doctors about the following disorders in the patient:
- The presence of systemic rheumatic diseases.
- The development of a digestive system disease.
- Response due to transplant rejection.
- The presence of malignant tumors in the body.
- The development of secondary amyloidosis.
- The occurrence of myocardial infarction (appears on the second day of the disease, by the beginning of the third week, the protein disappears from the blood serum, and is completely absent with angina pectoris).
- The presence of sepsis in newborns.
- The development of meningitis, tuberculosis, or postoperative complications.
- The presence of neutropenia.
- The use of estrogen or any oral contraceptives.
A low level of this protein, as a rule, has no clinical value. Therefore, the best result is the absence of this protein.
Thus, at present, determination of CRP concentration is widely used in the framework of monitoring and control over the effectiveness of treatment of bacterial or viral infections, chronic inflammatory, and oncological diseases. Such an analysis is also important for gynecological complications.