A blood protein test is an informative screening test that helps diagnose and monitor the symptoms of kidney and liver diseases and metabolic syndromes affecting the normal functioning of the liver, pancreas, kidneys, etc. Changes in the concentration of total protein in the blood may indicate an unhealthy diet, the presence of acute and chronic inflammatory diseases.
Proteins are the building blocks of our body. Every cell in our body contains protein. Therefore, the analysis for proteins can provide a doctor with detailed information about the diseases, conditions, and functioning of organs of our body. It also helps to monitor how well therapies or treatments are working.
What is blood protein?
Total protein in the blood is the primary biochemical indicator that reflects amino acid metabolism in the human body. A blood test for total protein, as a rule, is carried out in combination with other biochemical indicators. Blood protein test informative in the diagnosis and monitoring treatment regimen of kidney and liver diseases, metabolic disorders, infections, monitoring the effectiveness of the therapy.
For the quantitative study of protein, venous blood plasma is used. Most often, this indicator is determined by the colourimetric method. The range of blood protein levels in healthy adults ranges from 65 to 85 g / L. The duration of the study is not more than one working day.
Excess” protein is not deposited in the body. Therefore proteins unused by the body are broken down into nitrogenous compounds, carbon dioxide, and water. Ammonia is rendered harmless in the liver with the formation of urea and excreted by the kidneys in the urine. The proteins involved in purine metabolism are converted to uric acid. The latter is excreted in urine and faeces.
The main function of serum proteins is to maintain the body’s homeostasis by participating in various biochemical processes. Plasma proteins maintain the acid-base state of the blood, are part of the blood coagulation factors, thereby affecting the degree of its “fluidity.” The quantitative content of proteins in the blood determines the level of colloidal osmotic pressure and the distribution of water between the body tissues. Proteins in the blood carry out a transport function by binding and transferring lipids, pigments, hormones, drug fragments to human tissues and organs. The globulin fraction of the protein has a protective function.
Total blood protein is the sum of all types of proteins circulating in plasma. The main fractions are albumin and globulins. Albumin is formed in the liver. Its fraction is homogeneous in its structure and makes up about 60% of the total amount of proteins. Globulins are represented by a heterogeneous composition; they are formed in the liver and reticuloendothelial system (lymphocytes and plasma cells). The concentration of total protein depends on the rate of its synthesis from amino acids. Determination of the total protein level is performed during routine biochemical screening.
Why is the blood protein test done?
There are several symptoms in which a doctor may refer a patient for a blood protein test. It may prescribe as part of the first stage of a comprehensive examination to diagnose various diseases and conditions.
It is one of the main diagnostic measures for the following conditions:-
- Coffee ground vomitus, dark stools, and suspicious blood loss (internally or externally).
- Low urine output
- Oedema on the face and legs in the morning
- Diseases of the digestive tract and nutritional disorders
- Metabolic disorders
- Infectious diseases
- Loss of energy and drowsiness
- Prolonged diarrhoea
- Yellowing of the skin and whites of the eyes (jaundice)
- Decreased immunity and frequent colds
- Nephrotic syndrome:- excessive excretion of proteins by the kidneys, a decrease in oncotic (protein) pressure in the blood, and, as a result, fluid retention in the tissues.
- Pain in the bones and lumbar region:- Pain can signal the possible accumulation of abnormal protein in the bone tissue and kidneys.
- Sharp and unreasonable weight loss:- due to the rapid breakdown of protein in cancer and cachexia (Wasting Syndrome).
Additionally, the test helps monitor the effectiveness and outcome of the therapies and treatments of the following diseases:-
- Liver and kidney failure
- Autoimmune and oncological diseases
- Gastrointestinal disorders
What is the procedure for a blood protein test?
Preparation and collection of blood
The day before the test:-
- Avoid any food for 8-10 hours before taking the test. You can drink water, but it is better to avoid any sweet drinks – juices, soda, tea with sugar.
- It is necessary to avoid taking any emotional and physical stress and the consumption of alcohol.
On the day of the test:-
- You need to give blood in the morning from 8:00 to 11:00 on an empty stomach.
- Thirty minutes before the examination, you should not smoke or expose yourself to stress.
- A phlebotomist takes the blood sample from the veins of the cubital fossa or hand. He uses a disposable syringe with a dry test tube for blood collection. It is then labeled with the patient’s name and data and carried forward for analysis.
Blood protein test results
The amount of total protein varies with age. The average protein level looks like this:-
|Categories of people||Norm for women||Norm for men|
|Newborn||42-62 g / l||41-63 g / l|
|Children under 1 year||44-79 g / l||47-70 g / l|
|Children from 1 to 5 years old||60-75 g / l||55-75 g / l|
|Children from 5 to 8 years old||53-79 g / l||52-79 g / l|
|Children from 8 to 18 years old||58-77 g / l||56-79 g / l|
|Adults 18-35 years old||75 – 79 g / l||82-85 g / l|
|Adults 35-60 years old||79-83 g / l||76-80 g / l|
|Adults 60-75 years old||74-77 g / l||76-78 g / l|
|Over 75 years old||69-77 g / l||73-78 g / l|
Both high and low blood protein levels indicate multiple health problems.
Increased protein (hyperproteinemia):-
- Hyperproteinemia occurs when there are dehydration and thickening of the blood – it happens with a patient with extensive burns, dehydration (due to vomiting and diarrhea), cholera, and intestinal obstruction.
- An increase in total protein levels also indicates acute infectious diseases, sarcoidosis, chronic polyarthritis, and autoimmune diseases such as lupus.
Decreased total protein (hypoproteinemia) indicates:-
- Presence of diseases such as HIV, malignant neoplasms, diabetes mellitus, hepatitis, cirrhosis, and toxic liver damage.
- Diseases of the gastrointestinal tract, pancreas, kidneys, and anuria (impaired urinary excretion).
- Endocrine disorders (in particular, thyrotoxicosis)
- Lack of proteins in the diet
- Protein levels can decrease with excessive water intake and intravenous glucose.
What can affect the blood protein test results
- The level of total protein increases with prolonged tourniquet pressure during blood collection.
- A decrease or change in the total protein levels occurs in pregnancy when there is an increase in plasma volume of the blood and its thinning.
- The results of the analysis can be significantly affected by the medication taken by the patient. If you are taking any medication, be sure to inform your doctor about it.
- Medications that can increase protein levels are:- anabolics, ampicillin, anticonvulsants, immunosuppressants, barbiturates, furosemide, glucocorticosteroids, androgens, and insulin. Further, oral contraceptives, phenytoin, and prednisone can decrease protein levels.
Blood protein test risks and complications
A blood protein test is a safe procedure. Complications occur in a rare case. You may feel mild pain when drawing blood for tests. Other complications are:-
- Bruising (ecchymosis)
- Dizziness and fainting (vasovagal syncope)
The doctor recommends doing a blood protein test regularly, at least once a year. It is a simple, affordable, and very informative study that makes it possible to detect many diseases at an early stage of development. If diagnosed with hypoproteinemia and nephrotic syndrome, your diet must include foods rich in protein. High protein foods include lean meats (lamb, pork, beef, veal ), poultry foods (chicken, duck, turkey), fish and seafood (prawns, crab, lobster, clams), and dairy products (milk, yogurt, cheese).