RU2359618C1 - Method of predicting risk of chronic obstructive lung disease development in people with long smoking history - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to field of medicine, in particular to pulmonology and can be used for estimation of prediction of risk of chronic obstructive lung disease development. Method ensures increase of accuracy of COLD prediction in people with long smoking history. Patient's sputum is analysed. Level of α₁-antitripsin activity is determined and additionally level of α₂-macroglobulin activity is determined, and if values α₁=341.17±41.77 mIU/ml and α₂=76.81±6.84 mIU/ml and higher, risk of COLD development is predicted.

EFFECT: increasing accuracy of predicting COLD in people with long smoking history.

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Description

The invention relates to medicine, namely to therapy and pulmonology, and can be used to assess prediction of the risk of developing COPD in long-term smokers.

A known method for predicting the development of COPD among people who do not have signs of bronchial obstruction [1]. The essence of the known method consists in determining the clinical symptoms and risk factors from the history of life: shortness of breath, secondhand smoke, sputum production, cough, wheezing, cough with sputum lasting more than 3 weeks, sex, snoring. Set their gradations and numerical values. Then, prognostic factors F ₁ , F ₂ , F ₃ , F _{4 are} determined and when F _{4 is} greater than F ₁ , or F ₂ or F _{3, a} high risk of developing COPD is predicted, with a value of F ₂ greater than F ₁ , or F ₃ , or F ₄ - low risk of developing COPD.

There is also a method for predicting the development of chronic obstructive pulmonary disease among smokers [2]. Its essence lies in the fact that clinical symptoms and risk factors are determined from the history of life: indicator pack / years - A ₁ ; the degree of intensity of smoking - A ₂ , the number of cigarettes smoked per day - A ₃ ; which cigarettes smokes - A ₄ ; smoking experience in years - A ₅ ; the presence of shortness of breath or wheezing - A ₆ ; how many smokes on the length of cigarettes - A ₇ ; whether the number of cigarettes smoked has changed over the past five years - A ₈ ; inhalation of cigarette smoke - A ₉ ; the presence of sputum - A ₁₀ ; how often sputum is separated - A ₁₀ ; the degree of nicotine addiction in points according to the Fagerstrom test - A ₁₂ . Set their numerical values. Then, prognostic factors F ₁ , F ₂ , F _{3 are} determined, and when F ₃ or F _{2 is} greater than F _{1, a} high risk of the possibility of developing COPD is predicted, with a value of F ₁ greater than F ₂ or F _{3, a} low risk of the possibility of developing COPD is predicted.

The disadvantages of the known methods is that they were developed based on the assessment of clinical symptoms and risk factors from the history of life, which were identified as a result of a survey of patients with COPD and were subjective.

Closest to the proposed one is a method for determining risk factors for development and protective factors of chronic obstructive pulmonary disease based on the study of some genotypic marker systems [3]. The method consists in assessing anthropometric characteristics and signs of connective tissue dysplasia in patients with COPD and healthy people; studying the features of the distribution of genetic markers (erythrocyte antigens of the AB0, MN, Rh systems, such as earwax, hair color and iris); determination of activity levels of α ₁ -antitrypsin and total immunoglobulin E in blood serum; the study of the significance of the smoking factor, the characteristics of nicotine addiction and their relationship with genetic markers in patients with COPD.

A disadvantage of the known method is that practically healthy non-smokers volunteers were used as a comparison group, and not long-term smokers with a high risk of developing chronic obstructive pulmonary disease, which reduces the accuracy of the method.

A new technical challenge is to increase the accuracy of the method.

To solve the problem in a method for predicting the risk of developing COPD in long-term smokers by examining the body fluids of patients and determining the level of activity of α ₁ antitrypsin, a sputum test is performed, and the activity level of α ₂ macroglobulin is additionally determined and with values α _l = 341.17 ± 41 , 77 mIU / ml and α ₂ = 76.81 ± 6.84 mI / ml and higher predict a low risk of developing COPD.

What is new in the method is that a sputum test is carried out, the level of activity of α ₂ -macroglobulin is additionally determined and when α ₁ = 341.17 ± 41.77 mI / ml and α ₂ = 76.81 ± 6.84 mI / ml and higher predict low risk of developing COPD.

The method is as follows: sputum is collected from a patient, and the activity level of α ₁ antitrypsin and the level of activity of α ₂ macroglobulin are determined by the method [4].

Determination of the activity level of α ₁ -antitrypsin

The activity of α ₁ -AT is determined by inhibition of the arginine-esterase activity of trypsin.

Two experimental samples are prepared. One of which contains 1.9 ml of 0.05 M Tris HCl buffer pH 8.0 and 0.1 ml of 0.01% trypsin solution, and the second contains 1.8 ml of 0.05 Tris HCl buffer. 0.1 ml of a 0.01% trypsin solution and 0.1 ml of sputum are incubated for 5 minutes at 25 ° C, then 1 ml of a 1.5 mM BAEE solution is added. The control sample contains 2 ml of 0.05 M Tris-HCl buffer and 1 ml of 1.5 mm solution of BAE. At a wavelength of 253 nm, the increase in optical density of the experimental samples against the control is measured for 1 minute. The calculation of inhibitory activity is carried out according to the formula:

α ₁ -antitrypsin = (V ₁ -V ₂ ) · 2.73 mIU / ml,

where V ₁ , V ₂ - the increase in optical density of 1 and 2 experimental samples in 1 minute;

2.73 - estimated coefficient.

Determination of the activity level of α ₂ -macroglobulin

The activity of α ₂ -macroglobulin is determined by the persistent arginine-esterase activity of the trypsin-α ₂ -macroglobulin complex. The trypsin-α ₂ -macroglobulin complex is able to hydrolyze the synthetic substrate BAEE, which is expressed in an increase in optical density at a wavelength of 253 nm.

To 1.8 ml of 0.05 M Tris-HCl buffer pH 8.0 add 0.1 ml of diluted sputum and 0.05 ml of 0.1% trypsin solution. Incubated for 5 minutes at 25 ° C to form an inhibitor-trypsin complex. Then add 0.1 ml of a 0.3% solution of soy inhibitor, mix and after 5 minutes add 1 ml of a 1.5 mm solution of BAE. The increase in optical density at a wavelength of 253 nm for 10 minutes is measured. The inhibitor activity is calculated by the formula:

α ₂ -macroglobulin = E ₂₅₃ · 0.546 mIU / ml,

where E ₂₅₃ - the increase in optical density in 10 minutes;

2.73 - estimated coefficient.

The values of α ₁ and α _{2 are} calculated, and for values α ₁ = 341.17 ± 41.77 mI / ml and α ₂ = 76.81 ± 6.84 mI / ml and higher, a low level of COPD development is predicted.

The proposed method for predicting the risk of developing COPD in long-term smokers is illustrated by specific examples.

Example No. 1. Man K., 53 years old. The examination was carried out in the order of the regular medical examination. Profession - electrician. Smoking experience 30 years. Complained of coughing in the morning with the separation of a small amount (2-3 ml) of colorless sputum. Objective examination of the respiratory system: the chest is the correct form, symmetrically active in breathing, pulmonary sound percussion over the lungs, vesicular breathing, wheezing is not heard. Conclusion: during a physical examination of the respiratory system, pathological changes were not revealed. General blood test: white blood cells - 6.7 × 10 ⁹ / l; erythrocytes - 5.32 × 10 ¹² / l; hemoglobin - 136 g / l; platelets - 250 × 10 ⁹ %; ESR - 6 mm / hour; leukocyte formula: stab neutrophils - 4%, segmented neutrophils - 67%, eosinophils - 1%, basophils - 0%, monocytes - 1%, lymphocytes - 27%. Urinalysis: color - straw yellow, transparent, density - 1022, protein - not determined, sugar - not determined; microscopy: white blood cells 1-1-0, red blood cells 1-0-0 in the field of view. Conclusion: indicators of the general analysis of blood, urine within normal limits. ECG: sinus rhythm, correct, heart rate - 72 in 1 minute, the electrical axis of the heart is not deviated; conclusion: ECG within normal limits. According to the proposed method, a study of sputum was conducted on the activity of proteinase inhibitors and it was found that the level of activity of α ₁ antitrypsin was 341.17 IU / ml and α ₂ macroglobulin

76.81 IU / ml, which allows us to predict a low risk of developing COPD in a patient. An in-depth examination of the patient underwent spirography, the indices of which were: FEV-1 - 86.2% of the proper values, the Tiffno index - 78.6%, which is normal. On this basis, a conclusion was made about the absence of chronic obstructive pulmonary disease. In subsequent follow-up examinations for 2 years, the diagnosis of COPD was also not confirmed.

Example No. 2. Patient S., male, 55 years old, teacher. Smoking experience is 31 years. It was observed for 4 years. Complained of a productive cough during the day, more in the morning. The last 2 years began to notice shortness of breath with increased physical exertion. General blood test: white blood cells - 7.2 × 10 ⁹ / l; erythrocytes - 5.65 × 10 ¹² / l, hemoglobin - 155 g / l; platelets 228 × 10 ⁹ %; ESR - 8 mm / h, leukocyte formula: stab neutrophils - 2%, segmented neutrophils - 63%, eosinophils - 2%, basophils - 0%, monocytes - 1%, lymphocytes - 33%. Urinalysis: color - yellow, transparent, density - 1024, protein - not determined, sugar - not determined; microscopy: white blood cells 0-1-0, red blood cells 0-1 in the field of view. Conclusion: indicators of the general analysis of blood, urine within normal limits. ECG: sinus rhythm, correct, heart rate - 66 per minute, deviation of the electrical axis of the heart to the left, ECG within normal limits. During the observation, a sputum test was performed three times on the activity of proteinase inhibitors by the proposed method. The activity of α ₁ -antitripsin was 92.8-78.0 mIU / ml and α ₂ -macroglobulin was 22.1-14.4 mIU / ml, which allowed S. to be predicted to have a high level of risk of developing chronic obstructive pulmonary disease, given the large the duration of smoking. In the first two years of observation, spirography indicators were within normal limits: FEV-1 was 81-84% of the proper values, the Tiffno index was more than 70%. Based on this, the patient was diagnosed with chronic non-obstructive bronchitis. Four years after the start of the examination, spirograms showed a decrease in ventilation indicators: FEV-1 to 65.4% of the proper value, Tiffno index to 68.2%. The spirographic test with bronchodilators was negative, which indicated the irreversibility of bronchial obstruction. These functional tests in conjunction with the clinical picture of the disease (the appearance of shortness of breath with increased physical exertion, productive cough) were consistent with the diagnosis: chronic obstructive pulmonary disease, stage 2, stable phase. Thus, the forecast of a high risk of chronic obstructive pulmonary disease in patient C., made by the proposed method, on the basis of a stably low activity of antiproteinases in sputum, was confirmed by the development of the disease.

Under observation were 30 people (a group of long-term smokers). They were examined (objective examination, general blood count, spirography) for the detection of COPD. After the traditional examination, all patients revealed the presence of a productive cough with a small amount of sputum, mainly in the morning. According to the results at the time of the examination, all patients in this group showed the absence of COPD; it was not possible to predict further development of COPD based on traditional tests. Simultaneously with the traditional survey, a survey was conducted according to the proposed method with determining the level of activity of α ₁ -antitripsin and α ₂ -macroglobulin. In 24 patients, the level of activity of α ₁ -antitrypsin was 341.17 ± 41.77, α ₂ -macroglobulin - 76.81 ± 6.84, in 6 patients, α ₁ -antitrypsin -80.24 ± 10.51, α ₂ - macroglobulin - 19.44 ± 5.11.

According to the survey by the proposed method, it was possible to predict the occurrence of COPD in patients in 20% of cases (6 patients). Patients were followed up for 2.9-3.8 years as part of annual medical examinations. During this time, the occurrence of COPD was confirmed in 6 patients with early (1-2) stages of COPD, in the remaining 24 patients during the observed period of time there were no signs of COPD, which suggests a more accurate prediction of the risk of developing COPD in long-term smokers persons using the proposed method.

The risk of developing COPD in smokers depends on the activity of the individual's “proteinase inhibitor” system. The activity level of α ₁ -antitrypsin = 341.17 ± 41.77 mIU / ml and α ₂ -macroglobulin = 76.81 ± 6.84 mIU / ml and higher in sputum indicate a low risk of developing chronic obstructive pulmonary disease. A lower concentration of these antiproteinases indicates a high risk of COPD.

Thus, the proposed method makes it possible to increase the accuracy of predicting the risk of developing COPD in long-term smokers who do not have functional signs of bronchial obstruction, which allows for the early prevention of this disease.

Literature

1. RU 2303956 C1, Yu. N. Krasnova and others. "A method for predicting the development of chronic obstructive pulmonary disease in people who do not have functional signs of lung disease among smokers", 2007.08.10.

2. RU 2303957 C1, Grimailova E.V. and others. "A method for predicting the development of chronic obstructive pulmonary disease among smokers", 2007.08.10.

3. Rybas A.V. “Gene-phenotypic marker systems in patients with chronic obstructive pulmonary disease”, abstract of the dissertation for the degree of candidate of medical sciences, Astrakhan, 2007 (prototype).

4. Nartikova V.F., Paschina T.S. "Method for determining the activity of a ₁ -AT by inhibition of arginine-esterase trypsin activity." Questions of medical chemistry, 1979, 25, pp. 399-502.

Claims (1)

A method for predicting the risk of developing chronic obstructive pulmonary disease in long-term smokers by examining the body fluids of patients, including determining the level of activity of α ₁ antitrypsin, characterized in that the study of sputum, further determine the level of activity of α ₂ macroglobulin and with values α ₁ = 341 , 17 ± 41.77 mIU / ml and α ₂ = 76.81 ± 6.84 mIU / ml and higher predict the risk of developing COPD.