The breadth of using biochemical blood tests in modern diagnostics requires the presence of at least some basic knowledge necessary for the patient to read the result handed to him by the laboratory assistant of the diagnostic center. Yes, with this piece of paper, you still go to the doctor, who sent you for analysis, but how sometimes you want to satisfy your curiosity and decipher the result of the biochemical blood test yourself, not postponing it indefinitely. This analysis is not limited to two or three indicators: this includes a whole range of different evaluation criteria. In this article you will read about the most important and frequently used of them.
More often, a decrease in the level of protein (hypoproteinemia) is diagnosed than an increase (hyperproteinemia). Protein concentration decreases with inadequate consumption of it from food, inflammation, chronic blood loss, increased disintegration or excretion of protein in urine, impaired absorption processes, poisoning, and feverish conditions. Hypoproteinemia is characteristic of the following diseases:
- inflammatory processes in the gastrointestinal tract (enterocolitis, pancreatitis),
- postoperative conditions
- renal (glomerulonephritis) and hepatic (hepatitis, cirrhosis, malignant neoplasms) pathologies,
- endocrine pathologies (diabetes mellitus, thyrotoxicosis),
Hyperproteinemia happens very rarely. At the same time, the content of abnormal and abnormal proteins increases. It occurs with systemic lupus erythematosus, rheumatoid arthritis, multiple myeloma.
Blood for protein is given in the morning on an empty stomach (the last meal should be no later than 8 hours before the test).
Above, we considered such an indicator as total protein. It consists of two fractions: albumin and globulins. Albumin is evenly distributed in the bloodstream and interstitial fluid. These proteins are capable of carrying hormones, medicinal substances, and metal ions.
The normal concentration of albumin is 40-50 g / l. Exceeding this level happens when:
- dehydration (diarrhea, vomiting, excessive sweating),
- multiple burns
- vitamin A abuse
A decrease in albumin can occur when:
- hepatitis, toxic liver cirrhosis,
- bleeding, injury, burns,
- increased blood vessel permeability,
- GI pathology, including absorption disorder (malabsorption syndrome),
- chronic heart failure
- pregnancy and breastfeeding,
- taking hormonal contraceptive tablets,
Blood is given in the morning on an empty stomach. 8 - 12 hours before the test can not eat and physically loaded.
Among alpha1-globulins, two fractions are of greatest interest: alpha1-antitrypsin and alpha1-acid glycoprotein.
Elevated levels of alpha1-antitrypsin indicate the presence of inflammation, emphysema, or (attention!) Malignant neoplasm. Normally, the content of this globulin should not exceed 2 - 5 g / l. In the body, it performs a regulatory function in blood plasma (responsible for the activity of its enzymes - trypsin, renin, thrombin, plasmin).
The diagnostic value of alpha 1-acid glycoprotein lies in the dynamic control of the inflammatory process and in the formation and further development of a malignant tumor (the increase indicates that a relapse has begun). The norm for alpha1-acid glycoprotein is a concentration of 0.55 - 1.4 g / l.
Here it makes sense to talk about the three fractions of globulins that have the greatest diagnostic value.
Alpha2 macroglobulins are part of the immune system. They perform a very important function - they block the growth of a malignant tumor. The normal concentration of alpha1-macroglobulins in the blood of an adult is 1.5–4.2 g / l. A decrease in this level may indicate the presence of acute inflammation, polyarthritis, rheumatism, and oncology. Increase - about cirrhosis of the liver, endocrine pathologies (diabetes, myxedema).
Haptoglobin in the blood should be 0.8 - 2.7 g / l. If less, then hemolytic anemia is possible, more - an acute inflammatory process. The main function of haptoglobin is the transport of hemoglobin to the place of its final destruction with the formation of bilirubin.
Ceruloplasmin oxidizes iron to trivalent and is a carrier of copper. The standard content for it is 0.15 - 0.6 g / l. An increase in ceruloplasmin can be a signal of acute inflammation or pregnancy. Reduction - congenital disorders of copper metabolism (Wilson-Konovalov disease).
In this group, the content of two protein fractions is estimated: transferrin and hemopexins. The main function of transferrin is iron transportation. In relation to transferrin, it is not its concentration that is detected, but the saturation with iron. An increase in saturation indicates an intensification of the breakdown of hemoglobin, which can occur with hemolytic anemia, a decrease - a possible iron deficiency anemia.
This group includes immunoglobulins - i.e. what we know as antibodies secreted by immunocytes for the destruction of foreign microorganisms. They should be normal 8 - 14 g / l. If more, then the immunity is activated by a bacterial or viral infection. A lower concentration of immunoglobulins may indicate both congenital pathology and chronic inflammation, oncology, glucocorticoid abuse, and allergies.
But do not rush to panic with increasing glucose concentration to 6 mmol / l and above: it is not necessarily diabetes. The increase in glucose - hyperglycemia - may be functional, for example, after eating, sweet drinking, or after strong experiences.
In other situations, hyperglycemia can serve as a precursor (and even indicate the presence) of a number of pathologies, among which there are very serious ones:
- neuroendocrine disorders (polycystic ovary syndrome, Itsenko-Cushing's disease, obesity, PMS),
- pathology of the pituitary (acromegaly, dwarfism),
- liver pathologies (infectious hepatitis, cirrhosis),
- pheochromocytoma (adrenal tumor).
Once there is hyperglycemia, it is reasonable to assume the existence of the opposite phenomenon, that is, hypoglycemia. She, like hyperglycemia, can be physiological (unbalanced diet, menstruation, overwork), which should not cause much concern: it is fixable. The situation with pathological hypoglycemia is quite different. It develops when:
- “Overdose” of insulin (just recall a few deaths among bodybuilders using insulin for anabolic purposes),
- failure of the liver, kidneys, heart,
- blood poisoning
- physiological or hormonal (glucagon, cortisol, adrenaline deficiency) exhaustion,
- hereditary anomalies.
Blood for glucose is taken both from a vein and from a finger. A prerequisite for donating blood for glucose is a complete rejection of food, starting in the evening. In the morning - if only to drink water (even tea is impossible). Eliminate physical and emotional stress.
If the bilirubin level is exceeded, the skin, iris and mucous membranes turn yellow. Hence the name bilirubinemia - jaundice. Jaundice may develop due to:
- hepatic pathologies (hepatitis, cirrhosis, poisoning with salts of heavy metals, alcohol), malignant neoplasms,
- hemolytic anemia,
- cholecystitis (blockage of the bile duct with a stone),
- sometimes during pregnancy.
There is still such a thing as jaundice of the newborn, caused by a massive breakdown of “extra” red blood cells (there is nothing dangerous here), prematurity, or a hereditary disease - Gilbert's disease.
By the way, high bilirubin can be associated with taking certain groups of drugs: antibiotics, oral contraceptives, indomethacin.
Low bilirubin is rare, usually in the presence of theophylline, barbiturates or vitamin C.
Urea is the result of the breakdown of protein compounds. If a person is healthy, then the urea content in his blood is within 2.8 - 8.3 mmol / l. A condition in which the "bar" urea content is higher than 8.3 mmol / l is called uremia. It does not always indicate that the patient is ill. For example, uremia can occur when there is an excess of protein in the diet (strength sportsmen), dehydration. In other cases, uremia means the presence of a disease:
- kidney problems (acute and chronic renal failure, pyelonephritis, glomerulonephritis),
- heart problems (heart failure, heart attack),
- liver problems (cirrhosis, viral or toxic hepatitis),
- no urine entering the bladder (anuria). For example, in case of compression of the urinary tract by a tumor or the presence of a stone in the ureter,
- inflammation of the peritoneum - peritonitis,
- bleeding with localization in the digestive tract,
- intoxication with phenol, chloroform, mercury salts,
Reduction of urea occurs very rarely. The reason for this can be physical work "for wear", which causes increased protein breakdown, pregnancy and lactation (during this period the body especially needs protein) or a small proportion of protein in the daily diet. In all the above states there is nothing extraordinary, you do not need to call an ambulance. Another thing - the pathological reduction of urea, which happens with celiac disease (congenital violation of the breakdown of cereal proteins), in the late stages of cirrhosis, with arsenic, phosphorus or heavy metal salts.
Creatinine - "slag" remaining in the muscle tissue after the breakdown of amino acids. Its normal content is 44-100 µmol / l, in athletes it may be somewhat higher.
Increased creatinine levels may be evidence of renal pathologies (pyelo- and glomerulonephritis, nephrosis or nephrosclerosis), the muscular system (pressure, trauma), the thyroid gland (thyrotoxicosis), ibuprofen, tetracycline, cefazolin, sulfanilamide, vitamin C intake.
And finally - a little about the final product of the exchange of purine bases, which is uric acid (the product, not the base). The decomposition of purines occurs in the liver, and uric acid is excreted by the kidneys. Normal levels of uric acid in men: from 210 to 430 µmol / l, and in women from 150 to 350 µmol / l.
First, the reasons for the physiological increase in uric acid levels:
- physical work,
- a diet rich in purines (legumes, meat, chocolate, red wine, seafood, coffee),
- toxicosis of pregnant women.
If we talk about the pathological increase in uric acid, then this is the first and most characteristic sign of gout. In this disease, only part of the uric acid is excreted by the kidneys. The rest is deposited in the form of crystals in the joints (first of all), kidneys, skin, eyes, heart, intestines. A major role in the development of gout is played by the burdened heredity and unhealthy diet, which consists in the consumption of a significant amount of products containing purines.
There is hyperuricemia (increased uric acid) and with blood diseases (leukemia, B12-deficient anemia), hepatitis, diabetes, skin diseases (psoriasis, eczema), tuberculosis, pneumonia.
Low uric acid levels are extremely rare.
Globulin Binding Sex Hormones
The liver produces most blood proteins, including SHBG, a sex hormone-binding globulin. For the body to work properly, part of the hormones must be connected. The bound hormone is inactive, while the free is active and fulfills all its functions. By linking "extra" hormones, protein limits their effect on the body.
SHBG binds progesterone, estradiol, testosterone, androstenedione, 5-dihydrotestosterone. When the amount of SHBG decreases, the concentration of active (free, unbound) hormones increases. With an increased amount of unrelated sex hormones, irregular menstrual cycles and facial hair growth (in women), breast enlargement (in men), and other effects can be observed.
If you suspect that you have increased or decreased globulin, consult your doctor. He will write out a referral to the GSPG analysis. Women can donate it on any day of the menstrual cycle.
Globulin elevated - possible causes:
- increased estrogen
- endocrine dysfunction,
- HIV infection,
- taking oral contraceptives.
Reduced SHBG levels are promoted by:
- increased levels of hormones (testosterone, cortisol, prolactin),
- polycystic ovary syndrome,
- cirrhosis of the liver,
- nephrotic syndrome,
- insufficient amount of thyroid hormones,
- syndrome of insufficient susceptibility of cells to insulin.
Globulins - a group of proteins that includes several subgroups: alpha-1, alpha-2, beta and gamma. Their number fluctuates during illness.
Fractions (groups) globulins
Acute inflammatory processes
Acute viral and bacterial diseases, myocardial infarction, early stages of pneumonia, acute polyarthritis, tuberculosis (exudative)
Chronic inflammatory processes
Cholecystitis, pyelitis, cystitis, late stages of pneumonia, chronic tuberculosis and endocarditis
Nephritis, toxicosis during pregnancy, tuberculosis (terminal stages), nephrosclerosis, nephritis, cachexia
Tumors in various organs with metastases
Liver poisoning, hepatitis, leukemia, oncology of the lymphatic and hematopoietic apparatus, dermatosis, polyarthritis (some forms)
Severe tuberculosis, chronic polyarthritis and collagenosis, liver cirrhosis
Cancer of the biliary tract and pancreatic head, as well as obstructive jaundice
↑ - means concentration is increasing
↓ means that the concentration is decreasing
Alpha globulins are divided into two categories: alpha-1-globulins and alpha-2-globulins.
The norm of alpha-1-globulin is 3–6%, or 1-3 g / l.
Among the alpha-1-globulins emit:
- alpha-1 lipoprotein,
These substances are also called proteins of the acute phase: they are produced in increased quantities with various organ damage (chemical or physical), viral and bacterial infections. They stop further tissue damage and prevent pathogens from reproducing.
The level of alpha-1 globulins increases with:
- viral and bacterial infection,
- acute and chronic inflammation,
- malignant tumor
- skin damage (burn, injury),
- changes in hormonal levels (steroid therapy, pregnancy),
- systemic lupus erythematosus,
- multiple pregnancy,
- malformations of the fetus or its death.
The level of alpha-1-globulins decreases when the work is disrupted:
- lungs (emphysema),
- liver (cirrhosis, cancer),
- kidneys (nephrotic syndrome),
- testicles (cancer) and oncology of other organs.
Their concentration normally ranges from 9 to 15% (6–10 g / l).
Among the alpha-2-globulins emit:
- alpha 2-glycoprotein,
- alpha 2 antiplasmin,
- protein A.
Among the substances of this group are proteins of the acute phase, as well as transport proteins.
The number of alpha-2 globulins increases with:
- liver damage (cirrhosis, hepatitis),
- tissue damage (burns, injuries),
- tissue necrosis (dying off)
- malignant tumors (with metastases),
- endocrine diseases (diabetes, myxedema),
- changes in hormonal levels (treatment with steroid hormones, pregnancy),
- autoimmune disease
- renal failure (nephrotic syndrome).
The concentration of alpha-2-globulins can be lowered by:
- insufficient amount of protein in food,
- rheumatic polyarthritis,
- diseases of the gastrointestinal tract,
- intestinal absorption disorder.
Most often in the analyzes (meaning proteinogram) the doctor is interested albumen (simple protein, soluble in water) and globulin (or globulins - proteins that do not dissolve in water, but are well soluble in weak alkalis and solutions of neutral salts).
Deviations from the norm (increase or decrease in the level of proteins) may indicate various pathological changes in the body: violation of the immune response, metabolism, transfer of products necessary for nutrition and respiration of tissues.
For example, a decrease in albumin concentration may indicate a decrease in the functional capabilities of the hepatic parenchyma, its inability to provide the required level of these proteins, as well as disruptions in the excretory system (kidneys) or the gastrointestinal tract, which is fraught with uncontrollable loss of albumin.
An increased level of globulins gives some reason to suspect inflammation, although, on the other hand, there are frequent cases when analyzes of a completely healthy person show an increase in the concentrations of globulin fractions.
Determination of the quantitative content of different groups of globulins is usually carried out by separation of the protein into fractions by electrophoresis. And, if the analyzes indicate, in addition to total protein, also fractions (albumin + globulins), then, as a rule, the albumin-globulin coefficient (A / G) is also calculated, which normally fluctuates within 1.1 - 2.1 . The norms of these indicators (concentration and percentage, as well as the value of A / G) are given in the table below:
|Protein fractions in blood plasma||Norm, g / l||The ratio of groups,%|
|Total protein||65 – 85|
|Albumen||35 - 55||54 - 65|
|α1 (alpha-1) -globulins||1,4 – 3,0||2 - 5|
|α2 (alpha 2) - globulins||5,6 – 9,1||7 - 13|
|β (beta) -globulins||5,4 – 9,1||8 - 15|
|γ (gamma) -globulins||8,1 – 17,0||12 - 22|
|Fibrinogen *||2,0 – 4,0|
|Albumin-globulin ratio in serum||1,1 – 2,1|
* There is no fibrinogen in serum, and this is the main difference between these biological media.
The rate of individual plasma protein fractions changes with age, which the following table may also indicate:
|Age||Albumen,g / l||α1, g / l||α2, g / l||β, g / l||γ, g / l|
|From 0 to 7 days||32,5 – 40,7||1,2 – 4,2||6,8 – 11,2||4,5 – 6,7||3,5 – 8,5|
|From 1 week to a year||33,6 – 42,0||1,24 – 4,3||7,1 – 11,5||4,6 – 6,9||3,3 – 8,8|
|From 1 to 5 years||33,6 – 43,0||2,0 – 4,6||7,0 – 13,0||4,8 – 8,5||5,2 – 10,2|
|5 to 8 years||37,0 – 47,1||2,0 – 4,2||8,0 – 11,1||5,3 – 8,1||5,3 – 11,8|
|From 8 to 11 years||40,6 – 45,6||2,2 – 3,9||7,5 – 10,3||4,9 - 7,1||6,0 – 12,2|
|From 11 to 21 years||38,9 – 46,0||2,3 – 5,3||7,3 – 10,5||6,0 – 9,0||7,3 – 14,3|
|After 21 years||40,2 – 50,6||2,1 – 3,5||5,1 – 8,5||6,0 – 9,4||8,1 – 13,0|
Meanwhile, one should not emphasize some discrepancy between the data in the table and from other sources. Each laboratory has its own reference values and, accordingly, norms.
Variety of globulin fractions
Since globulins are heterogeneous and differ in diversity even within their own group, it is possible that the reader will be interested in what each population is and what it is doing.
the proportion of different proteins in the blood
Alpha globulins - they respond first
a tangle of alpha and beta proteins on the example of hemoglobin
Group alpha 1 globulins It contains many important proteins:
- α1- antitrypsin, which is the main component of this subgroup, it inhibits proteolytic enzymes,
- α-acid glycoprotein, showing a number of advantages in the area of inflammatory reactions,
- Prothrombin is a protein that is an important coagulation factor,
- α1-lipoproteins, which ensure the transfer to the organs of lipids that are in a free state in the plasma after consuming a large amount of fat,
- Thyroxin-binding protein, which combines with thyroid hormone thyroxin and transports it to its destination,
- Transcortin is a transport globulin that binds and transports the "stress" hormone (cortisol).
Constituent fractions alpha 2 globulins are the proteins of the acute phase (their number prevails in the group and they are considered major):
- α2-macroglobulin (the main protein of this group), which is involved in the formation of immunological reactions during the penetration of infectious agents into the body and the development of inflammatory processes,
- Glycoprotein - haptoglobulin, which forms a complex compound with a red blood pigment - hemoglobin (Hb), which in a free state leaves the red blood cells (erythrocytes) when their membranes are destroyed in case of intravascular hemolysis,
- Ceruloplasmin is a metalloglycoprotein, a specific protein that binds (up to 96%) and carries copper (Cu). In addition, this protein belongs to the antioxidant capacity and oxidase activity against vitamin C, serotonin, norepinephrine, etc. (ceruloplasmin activates their oxidation),
- Apolipoprotein B is a carrier of “harmful” cholesterol - low density lipoprotein (LDL).
Alpha-1 and alpha-2-globulins are produced by liver cells, however, they belong to acute-phase proteins, therefore, during destructive and inflammatory processes, traumatic tissue damage, allergies, in stressful situations, the liver more actively begins to synthesize and secrete these proteins.
However, first of all, an increase in the level of α-fraction can be observed in the case of inflammatory reactions (acute, subacute, chronic):
- Pulmonary exudative tuberculosis,
- Infectious diseases,
- Burns, injuries and surgeries,
- Rheumatic fever, acute polyarthritis,
- Septic conditions
- Malignant tumor processes,
- Acute necrosis
- Reception of androgens,
- Kidney disease (nephrotic syndrome - α2-globulins increased, the remaining fractions - reduced).
A decrease in the level of alpha-globulin fraction is observed when the body loses proteins, intravascular hemolysis, respiratory failure syndrome.
Beta globulins: along with binding and transfer - the immune response
Β-globulin fraction (β1 + β2) includes proteins that also do not stand aside when solving significant problems:
- Iron transfer (Fe) - transferrin is involved in this,
- Binding of Hb heme (hemopexin) and preventing its removal from the body through the excretory system (iron care through the kidneys),
- Participation in immunological reactions (component of complement), which is why some beta globulins, along with gamma globulins, are referred to as immunoglobulins,
- Transport of cholesterol and phospholipids (β-lipoproteins), which increases the importance of these proteins in the implementation of cholesterol metabolism in general and in the development of atherosclerosis in particular.
The increase in the level of beta-globulins in the blood plasma is very often associated with the pathology that occurs with the accumulation of excessive amounts of lipids, which is used in the laboratory diagnosis of disorders of fat metabolism, diseases of the cardiovascular system, etc.
An increase in the concentration of beta-globulins in the blood (plasma, serum) is often observed during pregnancy, and, in addition to atherogenic hyperlipoproteinemia, always accompanies the following pathology:
- Malignant oncological diseases,
- Far advanced tuberculous process localized in the lungs,
- Infectious hepatitis,
- Obstructive jaundice
- IDA (iron deficiency anemia),
- Monoclonal gammopathy, myeloma,
- The use of steroid female hormones (estrogen).
Total protein in the blood is not always a reliable indicator of pathological changes in the body, therefore, in clinical laboratory diagnostics, it is not only its quantitative content that is important. An equally important parameter is the ratio of plasma proteins, the change of which (dysproteinemia) more eloquently may indicate these or other disorders, as well as their stage, duration of time and effectiveness of the therapy used. For example:
- The development in the body of an acute inflammatory reaction with tissue necrosis immediately activates the response of proteins of the acute phase - α1 and α2-globulin, as well as other acute-phase proteins. The increase in the values of these indicators is typical for acute infections caused by viruses, many acute inflammatory processes localized in the bronchi, lungs, kidneys, heart (myocardial infarction), as well as for tumors and traumatic tissue damage, including those obtained during surgical operations,
- γ-globulins increased, on the contrary, in the chronic course of the disease (chronic active hepatitis, cirrhosis of the liver, rheumatoid arthritis).
Thus, this laboratory test (proteinogram) is shown in any inflammatory reactions: acute, caused by infection or other causes, or chronic, resulting from systemic, autoimmune or other diseases. The ratio of protein fractions is determined in case of suspected protein starvation in case of malnutrition and bowel disease. In addition, the proteinogram is often used for screening and monitoring, which allows to identify hidden pathological processes, and monitor the development and treatment of previously established pathological conditions.