C-reactive protein (CRP or CRP from the English C-reactive protein) refers to plasma blood proteins. CRP in the biochemical analysis of blood is the most sensitive, it immediately responds by increasing the concentration level to the acute phase of any inflammatory process that occurs in the body.
Such a reaction plays a protective role. For diagnostic purposes, CRP analysis in parallel with ESR measurement is used as an indicator of the inflammatory process.
C-reactive protein - what is it
This protein got its name due to the ability of precipitation (from the Latin word praecipitatio, which literally means falling down, i.e. binding and precipitation). It binds to the C-polysaccharides of pneumococci and thereby protects the body from infection.
CRP stimulates the production of white blood cells, which are also a barrier to bacterial and other types of infection. Also, this protein enhances the functional activity of T-lymphocytes, which affects phagocytosis, agglutination and precipitation reactions that occur in the body.
The role of CRP in the body
What is the role of this protein in the body? CRP is used to remove fatty acids and bioactive lysophospholipids from the body, which are formed as a result of damage to cell membranes during any inflammatory process or tissue necrosis.
Phosphatidylcholine is the main element of all cell membranes. Normally, it is in the inner layer of the membranes and is not found on their surface. With any inflammation, damage to the cells, and therefore their membranes, occurs. Phosphatidylcholine appears on the outer layer of cell membranes. They are enriched with phosphatidylserine and phosphadylethanolamine. These phospholipids undergo hydrolysis and are converted into the strongest mediators of biochemical processes occurring in the body.
Thus, they contribute to the hemolysis (destruction) of red blood cells and have a destructive effect on the cell membranes themselves. This process provokes the formation of antibodies and other antigens that are exposed on the surface of the cell and become the binding site of CRP and the damaged cell membrane. Next, macrophages are activated, which subsequently absorb the remains of the damaged cell.
Thus, CRP in the biochemical analysis of blood is an indicator of tissue damage in any inflammatory process, trauma and necrosis.
Reasons for an increase in CRP
CRP is produced by liver cells and is a glycoprotein. CRP analysis - what is it? Under the influence of biologically active mediators (discussed above), namely, phospholipids hydrolyzed, the production of CRP is stimulated. Its content begins to rise after a few hours. And a day after the onset of an inflammatory or other pathological process, the CRP protein in a study of blood biochemistry can be ten times higher than normal. This is especially pronounced in bacterial infections.
CRP is also increased with necrotic changes in tissues that occur during heart attacks, strokes, and tumor decay. The results of recent medical studies have shown that an increase in this protein in blood serum is also characteristic of atherosclerosis of blood vessels. It was found that with atherosclerotic changes in the vascular bed there is a sluggish inflammatory process of the walls of blood vessels. Factors contributing to such a pathological change are:
- smoking,
- obesity,
- diabetes.
The effect of CRP on cardiovascular disease
Even a slight increase in CRP in a biochemical blood test may indicate the presence of a sluggish inflammation in the walls of blood vessels and thereby be a sign of atherosclerotic changes.
It is known that an increase in the level of low density lipoproteins (LDL) affects the formation of atherosclerotic plaques in the lumen of blood vessels. But recent studies have shown that patients with high levels of CRP in the blood and a normal level of LDL are at a much higher risk of developing cardiovascular pathologies than those whose CRP levels remain normal and their LDL levels increase.
In patients with coronary heart disease (CHD), as well as in patients who have had a stroke, heart attack or undergone a procedure of bypass surgery with stenosis of the coronary arteries, a positive CRP analysis (above normal) is a sign of a poor prognosis. This may indicate the possibility of a repeated stroke or heart attack, etc.
Biochemistry: CRP above normal. What is this talking about
CRP analysis - what is it and what can the increase of this indicator indicate? To begin with, it should be noted that the norm of this indicator in the blood is from 0 to 0.5 mg / l. Both pathological and physiological processes can influence an increase in its level in the blood. Let us first consider under what pathological conditions the value of CRP can increase.
Pathological processes that increase the level of CRP
So, this value increases in the following cases:
- After acute infections, especially if they were of a bacterial nature.
- With exacerbation of allergic or infectious and inflammatory processes, including with atherosclerotic changes in the walls of blood vessels.
- With any damage to the integrity of the tissues (heart attack, surgery, trauma, frostbite, burns, etc.).
- With the decay of tumors in the case of oncological processes and with the appearance of new metastases.
- With high blood pressure.
- With endocrine pathologies (obesity, diabetes, excess or lack of sex hormones, etc.).
- In cases of impaired protein metabolism.
- With atherosclerotic changes in the vessels.
- In people who abuse smoking.
Physiological conditions affecting CRP
In addition to these pathological conditions, some physiological conditions can influence the biochemical analysis of CRP. So, its level can increase with significant physical exertion, for example:
- Athletes during the period of competition or enhanced training.
- In women during pregnancy, especially if there is toxicosis.
- When taking hormonal contraceptives or other hormones.
- Drinking alcohol or fatty foods on the eve of a blood test.
- The presence of grafts or implants in the body.
When is CRP below normal?
In addition, the concentration of CRP in the biochemical analysis of blood may decrease slightly and be lower than normal with the use of certain medications, especially if the patient takes them for a long time. These drugs include:
- Glucocorticoid hormones.
- Nonsteroidal anti-inflammatory drugs.
- Beta blockers.
CRP: normal
CRP research is a very sensitive indicator. CRP analysis can be carried out using various techniques. Its indications may vary slightly depending on the sensitivity of various reagents. Therefore, in each laboratory that performs CRP analysis, the norm is indicated when the result is issued.
So, individual laboratories indicate the norm from 0 to 0.5 mg / l. And others, using different methods, note in the issued research results that the norm for CRP is from 0 to 0.3 mg / l. Therefore, when reading the result, you should always pay attention to the indicated norm.
In addition, they have recently begun to quantify the result of this analysis. Previously used the old technique, which gave approximate results. A quantitative expression of this analysis was given out in crosses. So, the result was considered "normal" (-) as the norm. If a positive result was found, then it was issued in the form of such an answer - "positive" (+). The number of crosses from one to four was written in brackets.
Diagnostic value of CRP
Among other indicators and survey methods, CRP is also important. So, this protein is the first to respond to the penetration of infection into the body or to the development of another pathology. Just a few hours after the development of myocardial infarction, the level of this indicator in the blood begins to increase. And in just a day, it can increase tens of times.
The study of this indicator in the dynamics allows the doctor to judge the effectiveness of the chosen treatment tactics. So, as the intensity of the rheumatic process or other pathology decreases, the level of CRP in the blood will decrease.
This analysis has long remained very informative, and even the development of new diagnostic research methods cannot displace it.
How to get tested for C-reactive protein
In order to pass such an analysis, special training is not required. But it should be borne in mind that all blood tests are usually taken in the morning on an empty stomach. During the day, some indicators may vary slightly, for example, glucose or white blood cells. A blood test is usually prescribed in combination. It can be rheumatoid tests, they just include the study of CRP, or a clinical blood test, where ESR is studied. All of them, along with examination and history taking, are important for the correct diagnosis.
Blood for CRP is taken from a vein in the treatment room of a clinic or any other medical institution.
Before donating blood for this study, in order to obtain a more reliable result, it is necessary to observe several simple rules:
- Dinner on the eve should not be too late and plentiful.
- Immediately before blood donation, it is not recommended to take any food and it is advisable not to smoke. Allowed to drink some water.
- On the eve, you should avoid taking any alcoholic beverages, too strong tea and coffee.
- A few hours before the test, it is not recommended to expose the body to overheating or, conversely, to hypothermia. In other words, you can’t go to the blood sampling immediately after the sauna, bath, from the beach or solarium, or swimming in the hole.
- In front of the office, it is advisable to sit and relax for a few minutes.
What diseases cause an increase in CRP?
If a CRP blood test is done, the norm is up to 0.5 mg / L. If the level of this indicator is higher, then in accordance with other symptoms in the patient, the following diseases can be suspected:
- Rheumatic systemic pathologies (rheumatoid arthritis, systemic lupus erythematosus , etc.).
- Acute bacterial infections.
- Fungal diseases.
- Gastrointestinal diseases (ulcerative gastritis, gastric or duodenal ulcer, ulcerative colitis, etc.).
- The collapse of a malignant tumor or metastasis in cancer processes.
- Multiple myelomas.
- Myocardial infarction (already on the second day after an attack of CRP, it rises and disappears only at the end of 3 weeks, in the case of angina pectoris, this indicator remains normal).
- Endocarditis.
- Secondary amyloidosis.
- Tuberculosis.
- Meningitis.
- Neutropenia
- Sepsis of the newborn.
- Complications after surgery, such as peritonitis or postoperative bleeding.
- In the case of transplantation, an increase in CRP may indicate a rejection reaction.
So, we found out everything about a study such as CRP analysis - what it is and under what conditions it can increase. The study of CRP in dynamics with cardiovascular pathology serves as a kind of marker and allows us to predict possible complications. This makes it possible to gain time and prevent the patient from deteriorating, to prevent complications.
How to treat elevated CRP
It should be understood that an increase in CRP is just a symptom, not a disease. Which of the possible pathologies indicates this symptom, the doctor decides. To do this, he needs to carefully study all the data obtained from the examination, examine the patient and thoroughly collect an anamnesis. After that, only the diagnosis will be finally established. Treatment is not prescribed for a specific symptom, but for the identified pathology as a whole.