RU93660U1 - TEST STRIP FOR DIAGNOSTIC OF NEPHROPATHY - Google Patents

Abstract

 A test strip for diagnosing nephropathy containing a substrate, on one edge of which there is a sensor element for indicating microalbuminuria, characterized in that an additional sensor element for indicating leukocyturia is also applied to the substrate, moreover, the substrate and sensor elements are made of the same material.

Description

The proposed technical solution relates to medicine, namely to nephrology, and can be used for rapid diagnosis of nephropathy.

Nephropathy is a group of diseases that have similar clinical and morphological characteristics. Currently, the term nephropathy refers to the entire complex of lesions of the arteries, arterioles, glomeruli and tubules of the kidneys resulting from exposure to the kidneys of numerous products of impaired carbohydrate metabolism excreted by the kidney in diabetes mellitus (Ignatova M.S., Veltishchev Yu.E. Pediatric nephrology: a guide for doctors. L .: Medicine, 1989, S. 287).

There are no specific symptoms of nephropathy. One of the constant and diagnostically significant marker of the preclinical stage of this disease is microalbuminuria - the appearance of a protein, namely albumin, in the patient's urine, combined with leukocyturia (Tareeva I.E. Nephrology: a guide for doctors. M .: Medicine, 2000. P.448 -449). Leukocyturia - the allocation of leukocytes with urine in an amount of more than 5 in the field of view of the microscope, and a steady increase in the content of leukocytes in the urine indicates the continued activity of this disease and has unfavorable prognostic value (Tareeva I.E. 2000. S. 82-87).

Since in most cases the manifestations of nephropathy in the initial stages are weak and are detected only by laboratory research methods (http://www.zagerclinic.ru/disease.php?id=345), various complex and expensive tests are currently used to diagnose nephropathy -systems and equipment allowing to identify and evaluate the severity of microalbuminuria, which is just one of the significant symptoms of nephropathy (Litvin A.Yu. Microalbuminuria: determination methods and clinical significance. // Consilium medicorum, 2001, T.3, No. 13, p. .25; Evremov Eva MA, LV Bychkova, SR Baybulatova Detection of renal disease at an early stage with the help of low molecular weight proteins. // Bulletin of Peoples' Friendship University, series Medicine 2002, №1, S.83-84).

The high frequency of nephropathy accompanying such "formidable" diseases such as diabetes mellitus, arterial hypertension, gestosis of pregnant women, the lack of modern test systems that allow for the rapid diagnosis of nephropathy at an early stage of the disease, and the systems are simple, reliable and affordable for practical use healthcare, in outpatient and home settings, dictate the need to develop new test systems to diagnose this pathology.

Conducted research on the medical-scientific and patent literature revealed various test systems and equipment for the diagnosis of nephropathy.

So, in the work of D.L.Ferdman and E.F. Sopin (Workshop on Biological Chemistry. - M.: Soviet Science, 1957, p. 71), a description of a measuring complex is intended, in particular, for the diagnosis of nephropathy. The complex includes a nephelometer, which consists of two main parts - a illuminator and a colorimeter, as well as a set of special chemicals and measuring instruments.

The disadvantages of this complex are the complexity and high cost of the equipment included in its composition, the need for specially trained and trained personnel to work with it, the complexity of the study: it takes at least 20 minutes to analyze one sample.

In the work of D.L. Ferdman and E.F. Sopin (Workshop on Biological Chemistry. - M.: Soviet Science, 1957, p. 76-79), a description of another measuring complex, also intended for the diagnosis of nephropathy, is given. The complex includes a photoelectric colorimeter, a cuvette, a photocell, a galvanometer, a centrifuge, and a set of special chemicals.

The disadvantages of this complex are the complexity and high cost of the equipment included in its composition, the need for specially trained and trained personnel to work with it, the complexity of the study: it takes at least 30 minutes to analyze one sample.

In this case, a significant drawback of the above diagnostic complexes is the insufficient reliability of the results of the diagnosis of nephropathy obtained with their help, due to the possibility of violation of the proportional relationship between the concentration of albumin and the optical density of the protein-dye complex with violation of the law of light absorption - Lambert-Bera (V. Menshikov Laboratory research methods in the clinic. M., Medicine, 1987, p.24).

Known kit ImmunoFA-MA, manufactured by CJSC NVO Immunotech (support@immunotek.ru; http://www.immunotek.ru), intended for the diagnosis of nephropathy, by quantifying the level of albumin in the patient's urine. The kit includes: a 96-well polystyrene plate sensitized with monoclonal antibodies to albumin, calibration samples containing known amounts of albumin, a control sample with known albumin content, albumin conjugate with peroxidase, phosphate-buffered saline with tween-20, pH 7 , 0 ± 0.5, a solution of a substrate based on 3.3 ', 5.5'-tetramethylbenzidine (TMB) with the addition of hydrogen peroxide, a stop reagent and a film for sticking the tablet.

The disadvantages of this kit are the complexity and high cost of the equipment and reagents that make up its composition, the need for additional complex and expensive equipment to conduct research and diagnosis: a vertical scanning photometer that allows measuring the optical density of a solution in the wells of a tablet at a wavelength of 450 nm, a thermostat dry-air, maintaining temperature + (37 ± 1) ° С, shaker, stopwatch, set of pipettes of semi-automatic single-channel and multi-channel variable volume with interchangeable tips, allowing you to select different volumes of liquid, glasses of chemical or volumetric flasks, filter paper, installation for distilled water, plastic or rubber gloves. Work with the set and equipment described above requires the presence of specially trained and trained personnel, while the laboriousness of preparing samples for research is great, and it takes a long time to analyze one sample.

The closest technical solution that we have chosen as a prototype is a test strip indicator URIBEL, manufactured by LLC Biosensor AN (http://www.biosensoran.ru/new_page_65.htm), used for rapid diagnosis of nephropathy. The URIBEL test strip contains a substrate - a strip made of plastic with a size of 5 × (60-75) mm, on one edge of which there is a sensor element for indicating microalbuminuria. The sensor element is a specially processed material 5 × (3-6) mm in size, containing a pH indicator located at a distance of 1-2 mm from the edge of the substrate, which ensures the course of reactions and the formation of a colored complex. A change in the color of the sensor element indicates the presence of protein in the urine and serves as the basis for the diagnosis of nephropathy.

The disadvantage of the prototype is the lack of reliability in the diagnosis of nephropathy, due, firstly, to the fact that when conducting a urine test of patients using the URIBEL test strip, it is possible to obtain false-positive results caused by taking the examined quinine preparations or drugs based on quinoline derivatives, insufficient cleanliness of the dishes for collecting urine, or the presence of traces of disinfectants in this dish, and, secondly, the fact that the URIBEL test strips do not allow leukocyturia to be indicated - the leading laboratory sign of this disease.

The purpose of the utility model is to increase the reliability of rapid diagnosis of nephropathy.

This goal is achieved by the fact that the test strip for the diagnosis of nephropathy, containing a substrate, on one edge of which is a sensor element for indicating microalbuminuria, introduced an additional sensor element for indicating leukocyturia. An additional sensor element for indicating leukocyturia is also applied to the substrate. The substrate and the sensor elements are made of the same material.

The figure shows a General view of the inventive test strip for the diagnosis of nephropathy.

The test strip for the diagnosis of nephropathy contains a substrate 1, on one edge of which 2 is a sensor element 3 for indicating microalbuminuria. An additional sensor element 4 for indicating leukocyturia is also applied to the substrate 1 at a distance of 3-4 cm from the sensor element 3 for indicating microalbuminuria. The substrate 1, the sensor elements 3 and 4 are made of the same material, for example, filter paper. The second end 5 of the substrate 1 of the test strip is intended for fixation by the operator (not shown in the figure) performing the study. Dimensions of the test strip: length 80-100 mm, width 5-10 mm.

Work with a test strip for the diagnosis of nephropathy is as follows.

For research, use fresh or daily urine collected in clean, dry dishes - a container. Take the second end 5 of the substrate 1 of the test strip into the hand, briefly immerse the sensor element 3 applied to the test strip to indicate microalbuminuria and the additional sensor 4 to indicate leukocyturia in the container with urine, and immediately remove the test strip. Excess urine is removed from the test strip. When a color change of the sensor element 3 to indicate microalbuminuria from yellow to blue, and when a color change of the sensor element 4 to indicate leukocyturia from yellow to purple, the patient is diagnosed with nephropathy.

Prototypes of the proposed test strips for the diagnosis of nephropathy were developed and manufactured at the Department of General and Clinical Biochemistry No. 1 of Rostov State Medical University, and were tested in the urological and endocrinology departments of the Rostov State Medical University clinic for 50 patients. All patients were diagnosed with nephropathy, which was subsequently confirmed in all 50 cases.

Thus, the proposed test strip for the diagnosis of nephropathy is easy to manufacture, use, and can significantly increase the reliability of the rapid diagnosis of nephropathy, both in medical institutions and at home.

The serial production of "Test strips for the diagnosis of nephropathy" can be easily adjusted both in the laboratory and in almost any enterprise that produces indicator test systems.

Claims (1)

A test strip for diagnosing nephropathy, containing a substrate, on one edge of which is a sensor element for indicating microalbuminuria, characterized in that an additional sensor element for indicating leukocyturia is also applied to the substrate, moreover, the substrate and sensor elements are made of the same material.