CN111721941B - Device for judging sepsis infection condition and application thereof - Google Patents

Abstract

The invention provides a device for judging sepsis infection and its application. The input variables of the device include the concentrations of C-reactive protein, procalcitonin and interleukin-6, and a device for judging sepsis infection is constructed by using the concentrations of these three markers as input variables. The output variable of the device is mScore or mScoreplus. Using mScore or mScoreplus as a new indicator of sepsis infection to judge the degree of infection in patients has high accuracy, and can also distinguish bacterial infection from viral infection, helping clinicians to make an accurate diagnosis. An effective tool for monitoring disease.

Description

A device for judging sepsis infection and its application

technical field

The invention relates to the technical field of medical identification, and relates to a device for judging sepsis infection and its application.

Background technique

Septicemia refers to the acute systemic infection caused by various pathogenic bacteria invading the blood circulation, growing and multiplying in the blood, and producing toxins. If the bacteria that invade the bloodstream are cleared by the body's defense function, it is called bacteremia when there are no obvious symptoms of toxemia. Sepsis with multiple abscesses and a longer course is called sepsis (sepsis).

Sepsis is a life-threatening disease caused by a dysregulated inflammatory immune response, a systemic infection caused by bacteria, bacteria, and viruses that leads to organ and immune system dysfunction. The incidence of sepsis is high, and the condition is dangerous, and the case fatality rate is high. To treat sepsis, the first step is to understand the pathogen information and the host immune system information. Bacterial culture is the main strategy for confirming the presence of bacteria.

Traditional sepsis diagnosis takes 1 to 5 days from bacterial culture to identification of small molecules. Obtaining detailed information on viable bacteria and antibiotic susceptibility information directly from whole blood is difficult and time-consuming due to the lack of a bacterial culture step. Once the pathogens are isolated and cultured, antibiotic susceptibility testing can be performed to understand the sensitivity (or tolerance) of pathogenic microorganisms to various antibiotics, so as to guide the use of antibiotics. However, as can be seen from the new coronavirus COVID-19, the isolation and cultivation of pathogens is very dangerous, requiring operators to wear protective clothing in a clean room.

POCT (Point-of-Care Testing, bedside detection or point-of-care detection) sensors for pathogen identification are mainly based on the enrichment of magnetic particles of DNA or RNA, and then use PCR amplification to detect the corresponding targets. However, this method is usually used for common pathogenic microorganisms. Once uncommon pathogens are encountered, it is difficult to detect them even with multiplex PCR. POCT sensors for generating pathogen information are still in development.

Due to the lack of a method for quickly judging the condition of patients with sepsis, the patient's condition will develop rapidly, and once the optimal treatment time is missed, the fatality rate will greatly increase. In wards, especially ICU wards, where patients' conditions often progress rapidly, there is a high demand for fast, easy-to-use, and accurate POCT sensors.

In addition to starting with pathogen information, the development of the patient's immune system and organ function can also be evaluated to determine the infection status of sepsis, such as analysis and use of complete blood count, cell information (such as cell stiffness and cell motility), protein biomarkers substances and some small molecules (such as lactic acid). These changes in cells and biomacromolecules often better reflect the changes in the patient's body information and the course of the disease. In particular, changes in some cytokines often represent abnormalities in the immune system. Cytokine Storm is a phenomenon in which cytokines are rapidly and massively produced when the immune system fights against pathogens. Cytokine signals immune cells (such as T cells and macrophages) to spread to the site of infection. At the same time, The cytokines in turn activate the secreting cells, stimulating them to produce more cytokines. Therefore, by monitoring the content of these cells and biomacromolecules, it can be used to understand patient information.

Host information is easier to obtain than bacterial information, and can directly reflect the immune response of each individual. In order to make the determination of protein biomarkers portable, integrated, small and fast POCT platforms are gradually developed by combining micro-electro-mechanical systems (Micro-Electro-MechanicalSystem, MEMS), microfluidic chips and micro-sensors.

Therefore, how to quickly and accurately use the detection data of these biomarkers to obtain individual health data such as infection status and vital signs to prepare POCT sensors and realize real-time monitoring of ICU patients is an urgent problem in this field.

Contents of the invention

In view of the problems existing in the prior art, the present invention provides a device for judging sepsis infection and its application. The device can guide doctors to perform early diagnosis of sepsis on ICU patients.

For reaching this purpose, the present invention adopts following technical scheme:

In a first aspect, the present invention provides a device for judging sepsis infection, the input variables of which are C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6). 6) Concentration.

The device provided by the present invention takes the concentrations of three biomarkers of CRP, PCT and IL-6 as input variables. After a patient is infected with a virus or bacteria, the cytokine IL-6 in the body is first expressed and rapidly increased, and then PCT and CRP are gradually expressed and reach a peak. Under normal circumstances, the IL-6 concentration is less than 50pg/mL, the PCT concentration is less than 0.5ng/mL, and the CRP concentration is less than 10μg/mL. The concentration range of CRP, PCT and IL-6 is close to 6 orders of magnitude, and it is easy to cause wrong judgments based on only one biomarker. Meanwhile, although PCT and CRP are widely used for sepsis monitoring, a downward trend in PCT and CRP may not indicate improvement in patients, especially when treated with antibiotics and other drugs. In this clinical situation, PCT and CRP gradually decreased with antibiotics, but sepsis remained severe.

Therefore, the joint detection of these three biomarkers can greatly improve the diagnostic accuracy and reduce the disease burden. In the device provided in the present invention, the combined use of multiple biomarkers can avoid misdiagnosis of a single biomarker, help clinicians to diagnose accurately and guide the precise use of antibiotics, which plays a vital role in the field of precision medicine . For ICU patients, systemic inflammatory response syndrome is very common, and the combined detection of the three biomarkers can guide doctors in the early diagnosis of sepsis in ICU patients.

Preferably, the concentrations of CRP, PCT and IL-6 are measured using a microfluidic in vitro diagnostic immune chip. The concentration of each biomarker in the patient's serum sample can be obtained simultaneously and accurately by using the microfluidic in vitro diagnostic immune chip.

Preferably, the input variables to the device also include white blood cell count and neutrophil percentage.

It should be noted that the white blood cell count and neutrophil percentage are blood routine data. Among them, white blood cells are divided into circulating granulocytes (Circulating granulocytes, CGP) and marginal granulocytes (Marginal granulocytes, MGP). In the present invention, the white blood cells measured by the white blood cell count are CGP. When infected with a virus, MGP increases, which leads to a decrease in CGP. Although white blood cell counts and neutrophil percentages often lead to misdiagnosis, their abnormal elevations often indicate the possibility of a bacterial infection.

In the present invention, new indexes mScore and mScorePlus for diagnosing infection are established based on multiple biomarkers and blood routine diagnostic data.

Among them, the calculation formula of mScore is shown in equation (1):

It should be noted here that the concentration unit of PCT is ng/mL, CRP is μg/mL, and IL-6 is pg/mL. Among them, x is the calculation coefficient of PCT, and x is taken from any number between 1 and 5; y is the calculation coefficient of CRP, and y is taken from any number between 1 and 5; z is the calculation coefficient of IL-6, and z Any number between 1 and 5.

Preferably, the calculation formula of the mScore is as shown in equation (2):

As a preferred technical solution of the present invention, the output variable of the device for judging the sepsis infection situation is mScoreplus, and the calculation formula of the mScoreplus is as follows:

When 4×10 ⁹ /L≤white blood cell count≤10×10 ⁹ /L and 50%≤neutrophil percentage≤70%, the calculation formula of mScoreplus is shown in equation (3):

mScoreplus = mScore(3);

When the white blood cell count is <4×10 ⁹ /L or the percentage of neutrophils is <50%, the calculation formula of mScoreplus is shown in equation (4):

mScoreplus=mScore+5×(white blood cell count-4)+2×(neutrophil percentage-50) (4);

When the white blood cell count > 10×10 ⁹ /L or the neutrophil percentage > 70%, the calculation formula of mScoreplus is shown in equation (5):

mScoreplus=mScore+5×(white blood cell count-10)+2×(neutrophil percentage-70) (5).

mScore and mScorePlus are effective tools for detecting infection, differentiating bacterial from viral infection, and monitoring disease.

As a preferred technical solution of the present invention, the device includes the following units:

Detection unit: detect the concentration of C-reactive protein, procalcitonin and interleukin-6 in the sample;

Analysis unit: use the detected concentrations of C-reactive protein, procalcitonin and interleukin-6 as input variables, and input them into the calculation formula for analysis;

Evaluation unit: output the mScore and/or mScoreplus of the individual corresponding to the sample, and judge the sepsis infection of the individual.

Preferably, the detection unit includes a microfluidic in vitro diagnostic immune chip; preferably, the detection unit also detects the values of white blood cell count and neutrophil percentage in the sample.

Preferably, the mScore ≥ 30 is interpreted as positive for infection, and the mScore < 30 is interpreted as negative for infection;

Preferably, the mScoreplus ≥ 80 is interpreted as positive for bacterial infection, the 30 ≤ mScoreplus < 80 is interpreted as positive for viral infection, and the mScoreplus < 30 is interpreted as negative for infection.

In the second aspect, the application of the device for judging sepsis infection as described in the first aspect in the preparation of point-of-care detection (POCT) sensors.

The numerical ranges described in the present invention not only include the above-listed point values, but also include any point values between the above-mentioned numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention will not exhaustively list the ranges. The specific pip value to include.

Compared with the prior art, the present invention has at least the following beneficial effects:

(1) The device provided in the present invention takes three biomarkers of CRP, PCT and IL-6 as input variables. These three biomarkers are complementary, and can avoid For the misdiagnosis of a single biomarker, it can help clinicians to make an accurate diagnosis and guide the precise use of antibiotics; for ICU patients, CRP, PCT and IL-6 can guide doctors to make early diagnosis of sepsis in ICU patients;

(2) The device for judging the infection situation of sepsis provided in the present invention takes the concentration of CRP, PCT and IL-6 as input variables to obtain newly defined mScore and mScorePlus, and the size of mScore and mScorePlus is to a certain extent It reflects the severity of the infection, and there is no misjudgment in the detection of multiple samples, reducing misdiagnosis; and from the receiver operating characteristic curve, it can be seen that the AUC value of mScore is larger and the prediction performance is better;

(3) mScore and mScorePlus provided in the present invention are effective tools for detecting infection and distinguishing bacterial and viral infections. At the same time, the trend of mScore can also show the severity of infection, which can help clinicians to accurately diagnose and guide antibiotics and related drugs precise use.

Description of drawings

Fig. 1 is a graph showing the changes in the concentrations of CRP, PCT and IL-6 in patients during infection.

Figure 2 is the coefficient optimization curve of mScore.

FIG. 3 is a distribution diagram of mScore values under infection and non-infection states in Example 2.

4 is a waterfall diagram of the mScore level of each sample in Example 2.

Fig. 5 is the ROC curve chart of PCT, CRP, IL-6 and mScore used for diagnosing bacterial infection in Example 2.

Fig. 6(a) is a numerical distribution diagram of white blood cell counts during bacterial infection, viral infection and non-infection in Example 2.

Figure 6(b) is a numerical distribution diagram of the percentage of neutrophils during bacterial infection, viral infection and non-infection in Example 2.

Fig. 6(c) is a distribution diagram of mScorePlus values during bacterial infection, viral infection and non-infection in Example 2.

Fig. 7(a) is a histogram of the fold increase of biomarker concentration in representative serum samples in Example 2.

Figure 7(b) is a histogram of mScore and mScorePlus levels of representative serum samples in Example 2.

FIG. 8( a ) is a graph showing the concentration changes of PCT, CRP and IL-6 in ICU patient 1 in Example 3. FIG.

Fig. 8(b) is a graph showing the change of mScore value of ICU patient 1 in Example 3.

Detailed ways

The technical scheme of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation methods, but the following examples are only simple examples of the present invention, and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is based on rights Requirements shall prevail.

Example 1

In this embodiment, an inflammation indicator, ie, mScore, is defined to detect infection more accurately.

(1) The changes of CRP, PCT and IL-6 concentrations in patients during infection are shown in Figure 1; usually, the higher the concentrations of PCT, CRP and IL-6, the more severe the infection. These three biomarkers The combination of drugs can complement each other and improve the early diagnosis rate;

A new indicator, mScore, was defined based on the concentrations of these three biomarkers; mScore was calculated as follows:

Among them, x, y, z: calculation coefficients of different biomarkers.

First, assume all coefficients are 1, and only change one of them, then calculate the AUC value of the resulting mScore. As shown in FIG. 2 , when x=1, y=1 and z=3, AUC has a maximum value compared with x=1, y=1 and z=1 or 2, and its AUC=0.812.

By optimizing the coefficients in front of different biomarkers, we arrive at the following formula:

(2) According to the communication with clinicians, clinical variables such as blood test results, age and gender are also commonly used to judge the patient's disease status. The predictive performance of disease detection can be further enhanced by integrating this information into our established infection index mScore. At this point, mScorePlus is used to represent the index for further optimization.

The specific calculation formula of mScorePlus is as follows:

When the white blood cell count and the percentage of neutrophils have a natural range (that is, the white blood cell count is greater than or equal to 4 × 10 ⁹ /L and less than or equal to 10 × 10 ⁹ /L, or the percentage of neutrophils is greater than or equal to 50% and less than or equal to 70 %hour),

mScoreplus = mScore;

When the white blood cell count is less than 4×10 ⁹ /L or the neutrophil percentage is less than 50%, we calculate mScorePlus by the following formula:

mScoreplus=mScore+5×(white blood cell count-4)+2×(neutrophil percentage-50);

When the white blood cell count was greater than 10 × 10 ⁹ /L or the percentage of neutrophils was greater than 70%, we calculated mScorePlus by the following formula:

mScoreplus=mScore+5×(white blood cell count-10)+2×(neutrophil percentage-70).

Example 2

This example is used to study the clinical value of mScore and mScorePlus.

In this example, 70 serum samples were used, including 36 samples of bacterial infection, 24 samples of viral infection and 10 samples of healthy human serum, all of which were from the 306th Hospital of the Chinese People's Liberation Army, to prove that based on various The clinical value of new indicators mScore and mScorePlus for biomarkers and CBC information.

(1) Clinical value of mScore

1. mScore detects infection more effectively than individual biomarkers

As shown in Figure 3, the P value of mScore was less than 0.0001, and the mScores of infected and uninfected were 74.37±48.69 and 3.04±0.54, respectively. Compared with a single indicator, mScore has no misjudgment in distinguishing infection from non-infection.

2. mScore has higher accuracy in distinguishing bacterial and viral infections

As shown in Figure 4, it can be seen from the waterfall plot that the mScore of bacterial infection is higher than that of viral infection.

The area under the receiver operating characteristic curve (receiver operating characteristic curve, ROC curve) shows the area under the curve value (Area under the Curve, AUC) of each biomarker in diagnosing bacterial infection in patients. When AUC=1, use When using this prediction device, there is at least one threshold that can give a perfect prediction; when 0.5<AUC<1, it is a better random device. At this time, the larger the AUC value, the better the predictive performance of the biomarker.

As shown in Figure 5, it can be seen from the ROC curves of PCT, CRP, IL-6 and mScore that the ROC curves. The AUCs for PCT, CRP, IL-6, and mScore were 0.77, 0.67, 0.70, and 0.81, respectively; thus, mScore had the highest accuracy in distinguishing bacterial infections.

(2) Clinical value of mScorePlus

Compared with IL-6 and CRP, the concentration of PCT was lower in viral infection than in bacterial infection. mScore showed a similar trend to PCT. To make mScore better distinguish between bacterial and viral infections, we merged CBCs results into mScore to produce a more accurate metric: mScorePlus.

When infected with a virus, there is an increase in marginal granulocyte MGP, which leads to a decrease in circulating granulocyte CGP, and the leukocytes we usually measure are CGP. Although white blood cell count and neutrophil percentage often lead to misdiagnosis, as shown in Figure 6(a) and Figure 6(b), their abnormal elevation usually indicates the possibility of bacterial infection. Therefore, the white blood cell count and neutrophil percentage are also used as influencing factors to obtain the mScorePlus device. The distribution map of the obtained mScorePlus is shown in Figure 6(c), which can clearly distinguish bacterial infection, viral infection and uninfected samples.

Therefore, by combining white blood cell count and neutrophil percentage information into mScore, mScorePlus can accurately distinguish between bacterial and viral infections.

As shown in Figure 7(a), the abscissa indicates the number of the serum sample. There are certain abnormalities in the PCT, CRP and IL-6 concentrations of all representative serum samples. It is usually difficult to make a correct judgment for a single biomarker, because Their concentration varies widely, even without any abnormality. It would be misleading if we used only one of PCT, CRP and IL-6 as the disease state.

As shown in Fig. 7(b), all patients were found to be correctly diagnosed by examining mScore and mScorePlus of representative serum samples. Although PCT has been used as an important infection biomarker in ICU patients at present, IL-6 is usually more sensitive than PCT in the early stage of infection. It proves it.

Meanwhile, when comparing the values of mScore and mScorePlus, we found that mScorePlus may be smaller than mScore for viral infection, but not found in bacterial infection, where the dotted boxes in Fig. 7(a) and Fig. 7(b) are virus-infected patients .

Example 3

This example is used to prove that the development trend of the biomarkers provided in the present invention conforms to the theoretical trend.

Before admission to the ICU, patient 1's duodenal malignancy had not received gastrointestinal feeding for a long time, so fungal infection and secondary infection needed to be prevented.

After admission to the ICU, about 150 mL of blood was drawn from the abdominal drainage tube, which would cause a drop in blood pressure and further lead to hemorrhagic shock. Point-of-care detection of inflammatory biomarkers with our dynamic multiplex POC immunoassay is very helpful in judging and controlling infection.

As shown in Figure 8(a) and Figure 8(b), according to the test results and clinical symptoms, the patient was diagnosed with mild abdominal infection. Meropenem for injection is used to treat infections. However, a marked increase in IL-6 the next day indicated an uncontrolled infection. The patient was initially identified as having an infection caused by a gram-positive coccus (alpha-hemolytic streptococci). Meropenem is used with teicoplanin to treat bacterial infections until the infection is fully controlled.

At the same time, this example also proves that the trend of mScore can also show the severity of infection.

According to the definition of mScore, the size of mScore reflects the severity of infection to some extent. As shown in Figure 8(b), the trend of mScore can also effectively monitor the infection, and the intensification and decay of infection can be seen from the increase and decrease of mScore.

To sum up, how to obtain the concentration of multiple biomarkers accurately and quickly is very important for accurately and timely determining the patient's condition. The combination of CRP, PCT and IL-6 has been shown to be complementary and improve diagnostic accuracy. mScore based on these biomarker combinations can further enhance the predictive performance of disease surveillance. The new indicators mScore and mScorePlus provided by the present invention can improve the clinical significance of single biomarkers, and can combine CRP, PCT and IL-6 to evaluate the physiological status of patients. An effective tool for viral infection, it can also reduce the possibility of misdiagnosis and improve the accuracy of early diagnosis.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, and those skilled in the art should understand that any person skilled in the art should be aware of any disclosure in the present invention Within the technical scope, easily conceivable changes or substitutions all fall within the scope of protection and disclosure of the present invention.

Claims (6)

1. A device for determining the condition of a sepsis infection, wherein the input variables of the device include concentrations of C-reactive protein, procalcitonin, and interleukin-6, and the input variables of the device further include white blood cell count and neutrophil percentage;

the output variable of the device is mScorplus;

when 4 is multiplied by 10 ⁹ The white cell count of L is less than or equal to 10 multiplied by 10 ⁹ And when the ratio of the ratio to the L is 50 percent or more and the percentage of the neutrophils is 70 percent or less, the calculation formula of the mScorplus is shown as an equation (3):

mScoreplus＝mScore (3)；

when the white blood cell count is less than 4 multiplied by 10 ⁹ When the percentage of/L or neutrophil is less than 50%, the calculation formula of the mScorplus is shown in the equation (4):

mScore = mScore +5× (white blood cell count-4) +2× (neutrophil percentage-50) (4);

when the white blood cell count is more than 10 multiplied by 10 ⁹ When the percentage of/L or neutrophil is more than 70%, the calculation formula of the mScorplus is shown in the equation (5):

mScore = mScore +5× (white blood cell count-10) +2× (neutrophil percentage-70) (5);

the mScorplus is more than or equal to 80 and is judged to be positive for bacterial infection, the mScorplus is more than or equal to 30 and is less than or equal to 80 and is judged to be positive for viral infection, and the mScorplus is less than 30 and is judged to be negative for infection;

wherein, the computation formula of the mScare is shown in the equation (1):

wherein x is the calculation coefficient of procalcitonin, and x is any number between 1 and 5; y is the calculation coefficient of the C reaction protein, and y is taken from any number between 1 and 5; z is the calculated coefficient of interleukin-6, and z is taken from any number between 1 and 5;

the device comprises the following units:

and a detection unit: detecting the concentration of C-reactive protein, procalcitonin and interleukin-6 in the sample;

analysis unit: taking the detected concentrations of the C-reactive protein, procalcitonin and interleukin-6 as input variables, and inputting the input variables into a calculation formula for analysis;

an evaluation unit: outputting the mScorplus of the individual corresponding to the sample, and judging the sepsis infection condition of the individual.

2. The device for determining sepsis infections according to claim 1, wherein the concentrations of C-reactive protein, procalcitonin and interleukin-6 are determined using a microfluidic in vitro diagnostic immuno-chip.

3. The apparatus for determining sepsis infections according to claim 2, wherein the mScore is calculated as shown in equation (2):

4. the device for determining the condition of a sepsis infection according to claim 1, wherein the detection unit comprises a microfluidic in vitro diagnostic immuno-chip.

5. The device for determining the condition of a sepsis infection according to claim 4, wherein the detection unit further detects the value of white blood cell count and percent neutrophils in the sample.

6. Use of a device according to any one of claims 1 to 5 for determining the condition of a sepsis infection in the manufacture of an on-line detection sensor.