Urine analysis according to Nechiporenko: interpretation of indicators, norms
The content of the article:
-
Brief characteristics of indicators
- Erythrocytes
- Leukocytes
- Cylinders
- Indications for urine analysis according to Nechiporenko
- How to collect urine for analysis according to Nechiporenko
- How is the analysis done
- Normal indicators of shaped elements
- Decoding of urine analysis according to Nechiporenko
Urine analysis according to Nechiporenko is a research method that determines the content of formed elements in 1 ml of material.
One of the main stages of urine analysis is the study of its microscopic characteristics. The object of study at this stage is the sediment, which is obtained by centrifuging the biomaterial. The study of the sediment allows you to identify in it the content and amount of organic components (leukocytes, erythrocytes, cylinders, epithelial cells) and elements of inorganic origin (crystalline and amorphous salts and bacteria).
Analysis according to Nechiporenko is the study of urine sediment formed during centrifugation
For microscopic examination of urine, several methods are used: study of urine sediment as part of a general analysis and quantitative calculation of formed elements (urine analysis according to Nechiporenko, Amburzhe and Addis-Kakovsky's samples, etc.).
The most common method for the quantitative determination of formed elements in urine is urine analysis according to Nechiporenko. A study using this technique is carried out to determine the number of formed elements (erythrocytes, leukocytes) and cylinders in 1 ml of urine.
Brief characteristics of indicators
The process of urine formation begins in the glomeruli of the kidneys, where the primary filtration of blood occurs, while in healthy people, the formed elements penetrate into the urine through the mucous membrane of the ureters, the departments of the renal glomeruli and the tubular system only in small quantities. With the development of an inflammatory reaction, cells penetrate into the kidneys and urinary tract through the filtration capsule of the nephron, a defect in the wall of the tubules or the vessels surrounding them. Due to the destruction of the tubules and cell infiltration, conditions are created for the excessive release of formed elements from the focus of inflammation into the urine. It is for the purpose of their detection that a study is carried out according to the Nechiporenko method.
Erythrocytes
Erythrocytes (from the Greek erythros - red and kytos - vessel, cell) - red blood cells, cells containing hemoglobin. The place of their formation and growth is the bone marrow. Function - transport of oxygen and carbon dioxide between the lungs and tissues of other organs. 1 ml of urine in a healthy person contains no more than 1000 erythrocytes. An increase in their number indicates pathology. Determination of the structure of erythrocytes allows you to concretize the pathology and determine the source of their appearance in the urine (urinary tract or kidneys).
Leukocytes
Leukocytes (from the Greek leuko's - white and kytos - vessel, cell) - white blood cells, cells that perform an immune function. White blood cells are produced in the lymph nodes and bone marrow. The norm of the content of white blood cells in 1 ml of urine is not more than 2000 leukocytes in men and not more than 4000 in women. The difference in indicators is explained by the structural features of the male and female urinary systems.
Cylinders
The cylinders are protein casts of the kidney tubules. These elements are composed of protein, cells and various inclusions. According to the composition and appearance, several types of cylinders are distinguished: hyaline, erythrocytic, granular, waxy, etc. Hyaline cylinders - can be found in healthy people in small quantities: no more than 20 cylinders in 1 ml of urine. The detection of these elements in significant quantities speaks of kidney damage, especially when the renal epithelium and erythrocytes are layered on them. Erythrocyte casts consist of compressed erythrocytes, their identification confirms the renal origin of hematuria (acute glomerulonephritis, renal vein thrombosis, kidney infarction, malignant hypertension). Granular and epithelial casts are built from cells formed as a result of the destruction of tubular epithelium. Their presence in the analysis of urine indicates kidney disease. Wax cylinders are formed from other types of sealed cylinders. They are found in kidney pathologies with damage and degeneration of the epithelium of the tubules.
Indications for urine analysis according to Nechiporenko
The study is prescribed in the following cases:
- the presence of signs of inflammation (an increase in white blood cells, red blood cells or cylinders) in the general analysis of urine;
- diagnosis of latent inflammatory disease;
- chronic pathologies of the kidneys, prostate, urethra and bladder;
- diagnostics of microhematuria and latent cylinduria;
- routine examinations of the kidneys for systemic and endocrine diseases;
- establishing the degree of predominance of leukocytes over erythrocytes;
- examination during pregnancy in case of deviations in the general analysis of urine;
- monitoring and evaluating the effectiveness of the therapy.
How to collect urine for analysis according to Nechiporenko
A number of factors can affect the composition of urine and distort the test results. These include drinking and eating patterns, medication, physical and emotional stress, and sexual activity. The appearance of red blood cells in the urine can be caused by intense physical activity, trauma to the urethra with a catheter. Women are advised not to have a urine test during their period. False leukocyturia is possible when the material is contaminated with secretions from the genital tract.
In order to obtain reliable results, you need to prepare for the study. On the eve of the test, you should limit the consumption of vegetables and fruits that can change the color of urine (beets, carrots, oranges, blackberries, blueberries, rhubarb), stop taking vitamin complexes, diuretics. The possibility of drug withdrawal should be discussed with the doctor.
Algorithm for collecting urine for research:
- Prepare in advance a clean container for urine sample (glass jar or disposable plastic container for collecting material);
- in the morning before urinating, thoroughly wash the external genitals with clean water without using detergents;
- collect the middle portion of the first morning urine, for which you need to delay urination a little between portions. The first amount of excreted urine is passed, the middle portion is collected in a prepared container, after which the rest of the urine is released into the toilet;
- the container is tightly closed and delivered to the laboratory in the morning of the same day.
How is the analysis done
In the laboratory, a 5-10 ml urine sample is placed in a centrifuge tube. Under the influence of centrifugal force, the biomaterial is split into its component parts: shaped elements, salts and other microscopic elements of urine settle to the bottom. The formed precipitate is placed in a counting chamber (device for counting elements under a microscope).
In 1 μl of sediment, the number of formed elements (leukocytes, erythrocytes and cylinders separately) is counted. In order to find out the number of formed elements in a certain volume of urine, use the formula: N = x * (1000 / V), where N is the number of leukocytes, erythrocytes or cylinders in 1 ml of urine, x is the number of formed elements counted in 1 μl of sediment urine, and V is the volume of urine taken for research. The number 1000 means the amount of sediment in μl.
Normal indicators of shaped elements
For a quick decoding of the analysis indicators, you can use the table of norms for urine analysis according to Nechiporenko.
| Indicators | Norm |
| Erythrocytes | Up to 1000 / ml |
| Leukocytes |
Men - up to 2000 / ml Women - up to 4000 / ml |
| Hyaline cylinders | Up to 20 / ml |
| Erythrocyte casts | Absent |
| Granular cylinders | Absent |
| Waxy cylinders | Absent |
| Epithelial casts | Absent |
In adults and children, these indicators will differ slightly.
Decoding of urine analysis according to Nechiporenko
Only one analysis according to Nechiporenko is not the basis for making this or that diagnosis. Most often, it becomes an indicator of a pathological process in the kidneys and is carried out as part of an additional examination if one or another pathology is suspected. When making a diagnosis, clinical symptoms, the results of all laboratory and instrumental research methods are taken into account.
In order for the analysis not to be distorted, certain rules must be followed when collecting material.
Hematuria (the appearance of erythrocytes, other formed elements, as well as hemoglobin and other blood components in the urine) can be caused by bleeding in any part of the genitourinary system. The main reason for the increase in the content of red blood cells in the urine is nephrological or urological diseases and hemorrhagic diathesis.
An excess of the reference values of erythrocytes in urine may indicate the following pathologies:
- urolithiasis disease;
- tumors of the genitourinary system;
- glomerulonephritis;
- pyelonephritis;
- cystitis;
- hemorrhagic diathesis;
- urogenital tuberculosis;
- kidney injury;
- arterial hypertension;
- systemic lupus erythematosus (lupus nephritis);
- poisoning with benzene derivatives, aniline, snake venom, poisonous mushrooms;
- inadequate anticoagulant therapy.
An increase in the number of leukocytes in the urine is called leukocyturia. Its detection in most cases means an inflammatory disease of the kidneys and / or the lower urinary tract:
- pyelonephritis;
- glomerulonephritis;
- cystitis;
- urethritis;
- prostatitis;
- stones in the bladder and ureter;
- tubulointerstitial nephritis;
- systemic lupus erythematosus;
- rejection of a kidney transplant.
YouTube video related to the article:
Anna Kozlova Medical journalist About the author
Education: Rostov State Medical University, specialty "General Medicine".
Found a mistake in the text? Select it and press Ctrl + Enter.
