KR102362951B1 - Method of predicting short-term mortality in ischemic stroke using the ratio of procalcitonin to c-reactive protein - Google Patents

Abstract

The present invention relates to a method for providing information for predicting short-term mortality in ischemic stroke using the ratio of procalcitonin (PCT) to c-reactive protein (CRP), and more specifically, to a method for providing the result of measuring PCT concentration and CRP concentration in blood samples isolated from individuals, and calculating the ratio of PCT concentration to CRP concentration (PC ratio) from the measured PCT concentration and CRP concentration as information for predicting short-term mortality in ischemic stroke. In the present invention, after collecting the medical records of patients diagnosed with ischemic stroke, and then retrospectively analyzing the data of patients with both PCT and CRP records, it was found that among several indicators including PCT and CRP, the PCT to CRP ratio (PC ratio) indicator is significantly correlated with short-term (90-day) mortality in ischemic stroke, and it was confirmed that the risk of short-term death increases as the index increases, and thus the PC ratio can be used as a predictive marker of short-term mortality after ischemic stroke.

Description

A method for predicting short-term mortality in ischemic stroke using the ratio of procalcitonin to c-reactive protein

The present invention relates to a method for providing information for short-term mortality prediction of ischemic stroke using the ratio of procalcitonin (PCT) to c-reactive protein (CRP), and more specifically , measuring the PCT concentration and CRP concentration in a blood sample isolated from an individual, and calculating the ratio of PCT concentration to CRP concentration (PC ratio) from the measured PCT concentration and CRP concentration information for short-term mortality prediction of ischemic stroke It relates to a method of providing as

Ischemic stroke remains the leading cause of mortality in most countries and is the third leading cause of death worldwide. In 2000-2008, the incidence was estimated to be 94-117 per 100,000 people, and stroke is reported to cause more than 17 million deaths worldwide every year. Therefore, ischemic stroke is a major health concern and social burden, and is a disease requiring enormous health care costs. In addition, early diagnosis and risk assessment are needed to reduce ischemic stroke-related mortality. For this reason, much effort has been made to identify markers of the severity and prognosis of ischemic stroke, bilirubin, gamma-glutamyl transferase, uric acid, fibrinogen, white blood Several biomarkers for use in ischemic stroke, such as cell, WBC) count, brain natriuretic peptide (BNP) and troponin I (TnI) have been proposed, but have been evaluated and evaluated in well-designed clinical studies. Due to the lack of validation, it is not widely used in clinical practice.

Stroke is divided into ischemic stroke and hemorrhagic stroke described above, and ischemic stroke accounts for about 70-90% of all natural events. In addition, most of these are associated with cardiac embolism and atherosclerosis. Previous studies have shown that systemic inflammation is associated with disease development and progression of ischemic stroke, and that CRP protein levels are associated with disease severity. PCT is a 116 amino acid precursor of calcitonin (a hormone produced by thyroid C cells) that is secreted stimuli by bacterial endotoxins or inflammatory mediators. In addition, PCT is a promising biomarker for the detection of sepsis and pneumonia, and it is reported that PCT levels are elevated at an early stage when the major trauma may be related to inflammation rather than infection. However, no studies have investigated the relationship between the ratio of PCT concentration to CRP concentration (PC ratio) and prognosis in ischemic stroke.

Accordingly, the present inventors made efforts to develop a method for predicting short-term mortality in ischemic stroke patients. As a result, it was confirmed that the PC ratio is related to short-term mortality in ischemic stroke patients, leading to the application of the present invention.

KR10-1732787 B KR10-2125034 B KR10-2019-0061040 A KR10-20170072215 A

Makris K, Haliassos A, Chondrogianni M, Tsivgoulis G Blood biomarkers in ischemic stroke: potential role and challenges in clinical practice and research Crit Rev Lab Sci 2018: 1-35. Sonderer J, Katan Kahles M Aetiological blood biomarkers of ischemic stroke Swiss Med Wkly 2015; 145: w14138. Carter AM, Catto AJ, Mansfield MW, Bamford JM, Grant PJ Predictive variables for mortality after acute ischemic stroke Stroke 2007; 38: 1873-80. Mazidi M, Katsiki N, Mikhailidis DP, Pella D, Banach M Potato consumption is associated with total and cause-specific mortality: a population-based cohort study and pooling of prospective studies with 98,569 participants Arch Med Sci 2020; 16: 260-72. Oz II, Yucel M, Bilici M, et al Is mean platelet volume a reliable marker to predict ischemic stroke in the follow-up of patients with carotid stenosis? J Stroke Cerebrovasc Dis 2016; 25: 404-9. Furlan J, Vergouwen M, Fang J, Silver F White blood cell count is an independent predictor of outcomes after acute ischemic stroke Eur J Neurol 2014; 21: 215-22. Luo Y, Li J, Zhang J, Xu Y Elevated bilirubin after acute ischemic stroke linked to the stroke severity Int J Dev Neurosci 2013; 31: 634-8. Weikert C, Drogan D, di Giuseppe R, et al Liver enzymes and stroke risk in middle-aged German adults Atherosclerosis 2013; 228: 508-14. Kawase S, Kowa H, Suto Y, et al Association between serum uric acid level and activity of daily living in Japanese patients with ischemic stroke J Stroke Cerebrovasc Dis 2017; 26: 1960-5. Di Napoli M, Papa F, Bocola V Prognostic influence of increased C-reactive protein and fibrinogen levels in ischemic stroke Stroke 2001; 32: 133-8 16. Chaudhuri JR, Sharma VK, Mridula KR, Balaraju B, Bandaru VCSS Association of plasma brain natriuretic peptide levels in acute ischemic stroke subtypes and outcome J Stroke Cerebrovasc Dis 2015; 24: 485-91. Taub PR, Fields JD, Wu AH, et al Elevated BNP is associated with vasospasm-independent cerebral infarction following aneurysmal subarachnoid hemorrhage Neurocrit care 2011; 15: 13-8. Barber M, Langhorne P, Rumley A, Lowe GD, Stott DJ D-dimer predicts early clinical progression in ischemic stroke: confirmation using routine clinical assays Stroke 2006; 37: 1113-5. Barber M, Langhorne P, Rumley A, Lowe GD, Stott DJ Hemostatic function and progressing ischemic stroke: D-dimer predicts early clinical progression Stroke 2004; 35: 1421-5. Mimoz O, Edouard AR, Samii K, Benoist JF, Assicot M, Bohuon C Procalcitonin and C-reactive protein during the early posttraumatic systemic inflammatory response syndrome Intensive Care Med 1998; 24: 185-8.

The present invention has been devised to solve the problems of the prior art as described above, and the problem to be solved in the present invention is a biomarker for short-term mortality prediction of ischemic stroke, and information for short-term mortality prediction of ischemic stroke using the biomarker. An object of the present invention is to provide a diagnostic kit comprising a method and a reagent for measuring the blood concentration of the biomarker.

In order to solve the above problems, the present invention provides a biomarker for short-term mortality prediction of ischemic stroke, including procalcitonin (PCT) and c-reactive protein (CRP).

The PCT and CRP are preferably present as blood proteins.

In addition, the present invention comprises the steps of (1) measuring a procalcitonin (PCT) concentration and a c-reactive protein (CRP) concentration from a blood sample isolated from a subject; (2) calculating a ratio of PCT concentration to CRP concentration (PC ratio) from the measured PCT concentration and CRP concentration; and (3) providing the calculated PC ratio as information for short-term mortality prediction of ischemic stroke.

The PCT concentration and the CRP concentration are preferably protein concentrations.

The PC ratio is preferably a value obtained by dividing the PCT concentration by the CRP concentration.

The PCT concentration is preferably in units of ng/mL and the CRP concentration is mg/L.

If the PC ratio is 19.7×10 ⁻⁶ or more, it is preferable to determine that the short-term death possibility of ischemic stroke exists.

The short-term mortality rate is preferably within 90 days.

In addition, the present invention provides a set of reagents for specifically measuring the concentration of a biomarker including procalcitonin (PCT) and c-reactive protein (CRP) in a blood sample from a subject and ischemic disease from the subject It provides a diagnostic kit for providing information for short-term mortality prediction of ischemic stroke, including instructions for using the kit for providing information for predicting short-term mortality of stroke.

Preferably, the reagent measures the concentration of the protein.

In the present invention, after collecting medical records of patients diagnosed with ischemic stroke, retrospective analysis of data from patients with both PCT and CRP records showed that the ratio of PCT concentration to CRP concentration among various indicators including PCT and CRP. It was derived that the (PC ratio) index had a significant correlation with the short-term (90-day) mortality rate of ischemic stroke, and it was confirmed that the risk of short-term death increased as the index increased. can be used as a marker to predict

1 shows a ROC (receiver operating characteristic) curve of PCT, CRP and PC ratio for predicting 90-day mortality in ischemic stroke patients.
Figure 2 shows Kaplan-Meier survival estimates of ischemic stroke patients by PC ratio quartiles.

Hereinafter, the present invention will be described in detail.

The inventors of the present invention conducted a study to select blood biomarkers for predicting the prognosis of a patient diagnosed with ischemic stroke, and as a result, procalcitonin (PCT) and c-reactive protein (CRP) It was derived that the ratio of PCT concentration to CRP concentration (PC ratio) among several blood protein indicators including By confirming that is increased, the present invention was completed.

Accordingly, the present invention provides a biomarker for short-term mortality prediction of ischemic stroke, including PCT and CRP.

PCT and CRP as biomarkers of the present invention are individual, for example human, monkey, cow, horse, sheep, pig, chicken, turkey, quail, cat, dog, mouse, rat, rabbit or guinea pig, preferably It is preferred to be present as a blood protein in blood isolated from a mammal, more preferably a human.

The biomarker comprising PCT and CRP of the present invention is applied to a method for providing information for prediction of short-term mortality of ischemic stroke as follows.

Accordingly, the present invention provides a method comprising the steps of: (1) measuring a PCT concentration and a CRP concentration from a blood sample isolated from a subject; (2) calculating a ratio of PCT concentration to CRP concentration (PC ratio) from the measured PCT concentration and CRP concentration; and (3) providing the calculated PC ratio as information for short-term mortality prediction of ischemic stroke.

The subject is, for example, a human, monkey, cow, horse, sheep, pig, chicken, turkey, quail, cat, dog, mouse, rat, rabbit or guinea pig, preferably a mammal, more preferably a human.

The blood can be isolated from the subject by conventional clinical pathological means, and is preferably obtained by blood collection using an injection needle.

Preferably, the PCT concentration and the CRP concentration are the concentrations of proteins in the separated blood. The method for measuring the concentration of the protein is not particularly limited, but may be measured by, for example, one or more of an immunoassay, a colorimetric assay, a turbidity assay, and a flow cytometry method. The amount of the biomarker need not be determined under absolute conditions, but may be determined under relative conditions. Additionally, the amount of a biomarker may be expressed by its concentration in a biological sample, by the concentration of an antibody that binds the biomarker, or by the functional activity (ie, binding or enzymatic activity) of the biomarker.

The PC ratio of the present invention represents the ratio of the PCT concentration to the CRP concentration, and may be a value obtained by dividing the PCT concentration by the CRP concentration.

In the present invention, by analyzing the PCT and CRP concentrations of the study subjects, the correlation between their blood concentrations and short-term mortality, specifically, mortality within 90 days was revealed. As a threshold of high specificity (80%), the PCT concentration was set at 1.3 ng/mL, and the CRP concentration was set at 159.0 mg/L. A cut-off PC ratio of 19.7×10 ⁻⁶ was specified from the high specificity PCT and CRP concentration thresholds.

As a preferred embodiment, if the PC ratio is 19.7×10 ⁻⁶ or more, it may be provided as information for determining that the short-term death probability of ischemic stroke is high.

The biomarker of the present invention and the information providing method for short-term mortality prediction of ischemic stroke using the same can be provided in the form of a kit as follows.

Accordingly, the present invention provides a reagent set for specifically measuring the concentration of a biomarker including PCT and CRP in a blood sample from an individual and a kit for providing information for predicting short-term mortality from ischemic stroke from an individual. Provides a diagnostic kit for providing information for short-term mortality prediction of ischemic stroke, including instructions.

The diagnostic kit may include reagents and materials for measuring the level of one or more biomarkers in a sample from a subject, analyzing the measured level, and determining whether the subject is at risk of short-term death. In a preferred embodiment, the diagnostic kit of the present invention may include a needle, syringe, vial, or other device for obtaining and/or containing a sample from a subject. In some embodiments, a kit may include at least one reagent specifically used to detect or quantify a biomarker disclosed herein. That is, suitable reagents and techniques can be readily selected by one of ordinary skill in the art for inclusion in a kit for detecting or quantifying a biomarker.

Preferably, the reagent measures the concentration of the protein. In a preferred embodiment, an immunoassay (eg, chemiluminescent immunoassay), a colorimetric assay, or a turbidity assay may be used to detect a protein using an appropriate reagent (eg, an antibody). The reagents may also include extraction buffers or reagents, amplification buffers or reagents, reaction buffers or reagents, hybridization buffers or reagents, immunodetection buffers or reagents, labeling buffers or reagents, and detection means.

The diagnostic kit may include a control, which may be a control sample, a reference sample, an internal standard, or previously generated experimental data. Controls may correspond to normal healthy individuals or individuals with a known disease state. Additionally, a control may be provided for each biomarker or a control may be a reference risk score.

The diagnostic kit may include one or more containers for each individual reagent. The kit may further comprise instructions for performing the methods described herein and/or for interpreting the results in accordance with any regulatory requirements. Additionally, software for analysis of detected biomarker levels, calculation of risk scores and/or determination of likelihood of MI may be included in the kit. Preferably, the kit is packaged in a container suitable for commercial distribution, sale and/or use.

Hereinafter, the present invention will be described in more detail through specific examples. The following examples describe a preferred embodiment of the present invention, and the scope of the present invention is not limited and interpreted by the matters described in the following examples.

[Example]

1. Abbreviations

Definitions of abbreviations described in the Examples below are as follows.

CRP, c-reactive protein; WBC, white blood cell; BNP, brain natriuretic peptide; TnI, troponin I (troponin I); PCT, procalcitonin; AUC, area under the curve; PC ratio, the ratio of PCT concentration to CRP concentration (PC ratio); EMR, electronic medical record; ESR, erythrocyte sedimentation rate; CK-MB, creatine kinase muscle/brain; FDP, fibrin degradation product; IRB, institutional review board; SD, standard deviation; IQR, interquartile range; ROC, receiver operating characteristic; ANOVA, analysis of variance; OR, odds ratio; CI, confidence interval.

2. Research Methods

2.1. Study design and data collection

From February 2008 to January 2018, we checked the records of all patients admitted to Wonju Severance Christian Hospital (a tertiary university hospital located in Wonju, Korea) with an ischemic stroke diagnosis. To minimize confounding factors, records of patients with a history of trauma, febrile disease, autoimmune disease, community-acquired pneumonia, or major surgery were excluded. Patient data was collected from EMR.

We then assessed the association between PC ratio (PCT in ng/mL to CRP ratio in mg/L) and short-term (90-day) mortality. Serum PCT concentrations (reference range: ≤ 0.05 ng/mL) were determined by enzyme-linked fluorescence (VIDAS ^® PCT assay; bioMerieux, Marcy L'Etoile, France), and CRP concentrations (reference range: < 3.0 mg/L) were Immunoturbidimetric assay (Cobas ^® c 702 module; Roche Diagnostics, Basel, Switzerland) was used. The PCT concentration unit was converted to the same unit as the CRP concentration, and the PC ratio was calculated by dividing the PCT concentration by the CRP concentration, and the unit was expressed as 'value × 10 ^-6 '. All cases were followed for at least 90 days.

Study subject statistical and clinical data items were: age, sex, systolic and diastolic blood pressure, hospitalization and death date and risk factors (history of hypertension, diabetes, atrial fibrillation, congestive heart failure, coronary occlusive disease and malignancy) of existence.

Laboratory data were obtained as follows: WBC counts and neutrophils (%) were measured with an ADVIA 2120i automated haematology analyzer (Siemens Healthcare Diagnostics Manufacturing Limited, Dublin, Ireland); ESR was measured with a TEST-1 analyser (SIRE Analytical Systems, Udine, Italy); BNP and CK-MB were measured with an Atellica IM 1600 analyzer (Siemens); FDP, D-dimer and fibrinogen were measured with a CS-5100 hemostasis system (Sysmex Corp., Kobe, Japan).

This study was conducted after obtaining IRB approval from Wonju Severance Christian Hospital (IRB no. CR318057). This study was conducted using retrospectively collected data and laboratory results. No personal or medical information other than those required for analysis was collected.

1.2. data analysis

The study subjects were divided into survivors and non-survivors, and baseline characteristics were analyzed. The Kolmogorov-Smirnov test was used to confirm the normality of the numeric data, and when the p value was greater than 0.05, the data distribution was determined as parametric data. For parametric data, the results were expressed as mean ± standard deviation (SD) and compared using Student's t-test. For non-parametric data, the results were presented as medians and interquartile ranges (IQR), and were compared using the Mann-Whitney U test.

Then, using ROC curve analysis, various parameters including PCT, CRP, and PC ratio were compared to predict 90-day mortality. AUC was calculated. It was confirmed that the specificity was low (50-65%) in that the sensitivity and specificity were the same. Therefore, to minimize the false positive rate, a fixed threshold of high specificity (80%) was calculated. For laboratory results, the number of patients with abnormal values (above threshold) was further analyzed. In addition, diagnostic efficiency was further evaluated according to various PC ratio cut-off values to determine the mortality rate of stroke patients. Sensitivity, specificity, positive predictive value, negative predictive value, agreement rate, positive likelihood ratio, and negative likelihood ratio It was calculated according to the cut-off value.

Results for numerical data were compared using ANOVA or Kruskal-Wallis test (for parametric or non-parametric data, respectively), and if significant differences were found, pairwise comparisons were made using Tukey's adjustment.

Categorical data were expressed as frequency and percentage, and group categorical variables were compared using the Chi-Square test. And, univariate and multivariate logistic regression analysis were performed before and after adjusting for confounding variables. Survival analysis was performed using Kaplan-Meier estimation, and statistical significance was confirmed using the log rank test. For all statistical analyzes, p < 0.05 was considered statistically significant.

Analysis was performed using SPSS version 20.0 (IBM Corp., Armonk, NY, USA) and Analyze-it version 5.01 (Analyse-it Software, Ltd., Leeds, UK) added-in Microsoft Excel 2010 (Microsoft Corp, Redmond, Washington, USA). ) was used.

2. Study Results

2.1. Baseline characteristics

A total of 675 patients met the inclusion criteria from February 2008 to January 2018. Among them, the records of 333 patients who had both PCT and CRP results were used for analysis. The basal characteristics of 333 patients are shown in Table 1 below. In addition, short-term survival (90 days) was assessed for all patients.

Basic characteristics of stroke patients Baseline variables Unit and thres-
hold Feature Survival Non-
survival P value Male Female P value n no. (%) 268 (80.5) 65 (19.5) - 201 (60.4) 132 (39.6) - Age years mean ± SD 73.1 ± 13.5 72.4 ± 12.3 0.719 71.1 ± 14.0 75.3 ± 11.5 0.419 Male no. (%) 161 (60.1) 40 (61.5) 0.829 Female no. (%) 107 (39.9) 25 (38.5) Medical history of Hyper-
tension no. (%) 42 (15.1) 9 (13.8) 0.714 33 (16.4) 18 (13.6) 0.536 Diabetes
mellitus no. (%) 22 (8.2) 6 (9.2) 0.790 20 (10.0) 8 (6.1) 0.233 Atrial
fibri-
llation no. (%) 35 (13.1) 10 (15.4) 0.623 25 (12.4) 20 (15.2) 0.514 Heart
failure no. (%) 9 (3.4) 6 (9.2) 0.041 ^* 8 (4.0) 7 (5.3) 0.597 Coronary
artery
occlusive
disease no. (%) 9 (3.4) 2 (3.1) 0.909 5 (2.5) 6 (4.5) 0.355 Malignancy no. (%) 17 (6.3) 2 (3.1) 0.308 13 (6.5) 11 (8.3) 0.524 Clinical findings ^† Systolic
blood
pressure mmHg mean ± SD 128.3 ± 29.3 118.4 ± 26.7 0.032 ^* 125.9 ± 28.4 127.4 ± 29.8 0.701 Diastolic
blood
pressure mmHg mean ± SD 74.1 ± 16.7 71.8 ± 18.2 0.386 74.7 ± 16.8 72.2 ± 17.7 0.280 Laboratory findings ^† White
blood cell 15.5×10 ⁹ /L no. (%) 54 (19.6) 16 (28.1) 0.156 43 (21.4) 27 (20.5) 0.891 Neutrophil 88.2
% no. (%) 56 (20.3) 20 (35.1) 0.023 ^* 46 (22.9) 30 (22.7) 0.999 PCT 1.3 ng/mL no. (%) 52 (18.8) 24 (42.1) < 0.001 ^* 46 (22.9) 30 (22.7) 0.999 CRP 159.0 mg/L no. (%) 57 (20.7) 14 (24.6) 0.484 50 (24.9) 21 (15.9) 0.056 ESR 18.0 mm/h no. (%) 181 (65.6) 31 (54.4) 0.130 125 (62.2) 87 (65.9) 0.560 BNP 453.6 pg/mL no. (%) 30 (10.9) 10 (17.5) 0.179 20 (10.0) 20 (15.2) 0.170 CK-MB 3.3 ng/mL no. (%) 180 (65.2) 38 (66.7) 0.879 133 (66.2) 85 (64.4) 0.814 FDP 22.2 μg/mL no. (%) 30 (10.9) 11 (19.3) 0.118 21 (10.4) 20 (15.2) 0.234 D-dimer 1569.0 mg/L no. (%) 34 (12.3) 13 (22.8) 0.057 20 (10.0) 27 (20.5) 0.010 ^* Fibrinogen 385.0 mg/dL no. (%) 116 (42.0) 21 (36.8) 0.555 76 (37.8) 61 (46.2) 0.140

* P value < 0.05 indicates statistical significance.

† Shows the number and percentage of patients with abnormal laboratory findings (exceeding the thresholds determined in Table 2).

As a result, it was confirmed that 65 patients (19.5%) died within the 90-day follow-up period. In terms of medical history, heart failure was more frequent (p = 0.041) and systolic blood pressure was higher in non-survivors (p = 0.032). In laboratory results, the proportion of patients with abnormal neutrophils (%) and PCT was higher in non-survivors than in survivors (p = < 0.001 and 0.023, respectively). On the other hand, when the basic characteristics of the study subjects were divided by gender and analyzed in the same way, there was no significant difference between males and females (p > 0.05).

2.2. Check the predictive power of PCT, CRP and PC ratios

It was confirmed that PCT and CRP values in non-survivors tended to be higher than in survivors, but did not show statistical significance. However, it was confirmed that the average PC ratio of non-survivors (16.5, IQR 4.4-45.6) was significantly higher than that of survivors (5.0, IQR 2.0-17.0) (p = 0.002). The results of the ROC curve analysis are shown in FIG. 1 and Table 2. In addition, the diagnostic efficiencies according to various PC ratio cut-off values for determining mortality in stroke patients are shown in Table 3 (mean and 95% confidence intervals are indicated).

ROC curve analysis Parameter Mortality AUC 95% CI P value Threshold
(80% specificity) Sensitivity at decision point (%) PCT 0.676 0.597-0.754 0.005 1.3 ng/mL 42.1 CRP 0.530 0.441-0.619 0.436 159.0 mg/L 24.6 PC ratio 0.699 0.629-0.770 0.002 19.7×10 ^-6 47.4 WBC 0.523 0.437-0.609 0.581 15.5×10 ⁹ /L 28.1 Neutrophil 0.614 0.530-0.697 0.008 88.2% 34.5 ESR 0.534 0.447-0.621 0.486 18.0 mm/h 29.5 BNP 0.644 0.547-0.741 0.007 453.6 pg/mL 31.3 CK-MB 0.622 0.507-0.738 0.067 3.3 ng/mL 42.4 FDP 0.637 0.523-0.751 0.043 22.2 μg/mL 37.9 D-dimer 0.581 0.483-0.679 0.070 1569.0 mg/L 31.7 Fibrinogen 0.539 0.428-0.650 0.441 385.0 mg/dL 30.0

Diagnostic Efficiency (Mean and 95% Confidence Intervals) for Determining Stroke Mortality at Various PC Ratio Cut-Off Values Cut-
off Sensitivity
(%) Specificity
(%) PPV
(%) NPV
(%) LR+ LR- ≥0.9 91.2 (87.6-94.0) 6.2
(4.0-10.4) 16.7 (8.8-28.4) 77.3 (73.6-82.2) 0.97 (0.86-1.08) 1.42 (1.14-3.38) ≥2.2 84.2 (79.9-88.6) 27.2 (21.4-31.1) 19.3 (10.4-29.8) 89.3 (86.7-92.4) 1.16 (0.35-3.46) 0.58 (0.34-1.04) ≥3.5 75.4 (65.5-81.0) 38.4 (29.0-44.5) 20.2 (11.9-32.3) 88.3 (85.6-91.7) 1.22 (0.33-4.14) 0.64 (0.35-1.18) ≥6.4 63.2 (55.7-76.4) 52.5 (48.7-56.2) 21.6 (12.5-33.6) 87.3 (85.1-91.3) 1.33 (0.53-4.50) 0.70 (0.48-1.03) ≥9.0 61.4 (52.9-73.7) 61.6 (58.2-64.1) 24.8 (14.1-39.8) 88.5 (85.4-91.9) 1.60 (0.44-4.65) 0.63 (0.43-1.03) ≥19.7 47.4 (23.9-62.9) 79.7 (77.0-81.1) 32.5 (12.4-61.9) 88.0 (84.7-91.5) 2.33 (1.14-4.49) 0.66 (0.46-0.99) ≥34.6 36.8 (13.8-56.5) 85.5 (84.7-86.5) 34.4 (12.1-63.0) 86.8 (84.1-88.6) 2.54 (1.45-5.36) 0.74 (0.52-1.14) ≥79.3 19.3 (4.9-38.7)) 89.5 (88.5-90.8) 27.5 (13.9-41.7) 84.3 (81.5-86.7) 1.84 (0.23-8.95) 0.90 (0.82-1.02)

Abbreviations in Table 3: PPV, positive predicted value; NPV, negative predictive value; LR+, positive likelihood ratio; LR-, negative likelihood ratio.

2.3. Determine the relationship between PC ratio and related variables

It was confirmed that 333 subjects had a PC ratio (×10 ^-6 ) quartile of 0-2.1 in the 1st quartile, 2.2-6.3 in the 2nd quartile, 6.4-19.6 in the 3rd quartile, and 19.7 in the 4th quartile. . In addition, the odds ratios for 90-day mortality compared to the lowest PC ratio quartile (0-2.1) were as follows: After adjusting for age, sex, medical history and laboratory results, the second quartile ( 1.47 (95% CI, 0.62-4.20) for the 2nd quartile (2.2-6.3, p = 0.440) and 2.54 (95% CI, 0.95) for the 3rd quartile (6.4-19.6, p = 0.048). -5.91), and 4.10 (95% CI, 1.73-9.80) for the 4th quartile (≥ 19.7, p = 0.002). Table 4 confirms the characteristics of patients by quartile of PC ratio. Most laboratory items showed statistical significance (p < 0.05), but only PCT showed a significant increase according to each quartile (p < 0.05 trend).

Patient characteristics according to quartiles with PC ratios Baseline variables Unit and threshold Feature Q1 Q2 Q3 Q4 P value n no. (%) 83 (24.9) 84 (25.3) 83 (24.9) 83 (24.9) - Age years mean ± SD 74.0 ± 14.3 74.8 ± 10.4 72.3 ± 11.1 70.1 ± 16.0 0.096 Male no. (%) 54 (65.1) 50 (59.5) 48 (57.8) 49 (59.0) 0.783 Female no. (%) 29 (34.9) 34 (40.5) 35 (42.2) 34 (41.0) Medical history of Hyper-
tension no. (%) 11 (13.3) 20 (23.8) 10 (12.0) 10 (12.0) 0.097 Diabetes
mellitus no. (%) 6 (7.2) 7 (8.3) 8 (9.6) 7 (8.4) 0.957 Atrial
fibri-
llation no. (%) 11 (13.3) 17 (20.2) 6 (7.2) 11 (13.3) 0.109 Heart
failure no. (%) 4 (4.8) 4 (4.8) 4 (4.8) 3 (3.6) 0.977 Coronary
artery
occlusive
disease no. (%) 1 (1.2) 2 (2.4) 2 (2.4) 6 (7.2) 0.134 Malignancy no. (%) 6 (7.2) 5 (6.0) 6 (7.2) 2 (2.4) 0.493 Clinical findings Systolic
blood
pressure mmHg mean ± SD 129.6 ± 18.7 128.1 ± 22.3 130.6 ± 28.8 116.8 ± 41.3 0.035 ^* Diastolic
blood
pressure mmHg mean ± SD 74.5 ± 11.6 74.2 ± 13.8 78.3 ± 19.9 67.7 ± 20.7 0.008 ^* Laboratory findings ^† White
blood cell 15.5×
10 ⁹ /L no. (%) 9 (10.8) 20 (23.8) 16 (19.3) 25 (30.1) 0.020 ^* Neutrophil 88.2% no. (%) 7 (8.4) 17 (20.2) 17 (20.5) 35 (42.2) < 0.001 ^* PCT 1.3 ng/mL no. (%) 0 (0.0) 2 (2.4) 16 (19.3) 58 (69.9) < 0.001 ^* CRP 159.0 mg/L no. (%) 17 (20.5) 10 (11.9) 15 (18.1) 29 (34.9) 0.014 ^* ESR 18.0 mm/h no. (%) 62 (74.7) 57 (67.9) 46 (55.4) 47 (56.6) 0.026 ^* BNP 453.6 pg/mL no. (%) 5 (6.0) 7 (8.3) 10 (12.0) 18 (21.7) 0.010 ^* CK-MB 3.3 ng/mL no. (%) 59 (71.1) 56 (66.7) 46 (55.4) 57 (68.7) 0.429 FDP 22.2 μg/mL no. (%) 5 (6.0) 6 (7.1) 11 (13.3) 19 (22.9) 0.003 ^* D-dimer 1569.0 mg/L no. (%) 9 (10.8) 12 (14.3) 9 (10.8) 17 (20.5) 0.236 Fibrinogen 385.0 mg/dL no. (%) 28 (33.7) 36 (42.9) 30 (36.1) 43 (51.8) 0.081

* P value < 0.05 indicates statistical significance.

† Shows the number and percentage of patients with abnormal laboratory findings (exceeding the thresholds determined in Table 2).

2.4. Survival Analysis by PC Ratio

Logistic regression was used to evaluate the association between PC rates and 90-day survival. Table 5 shows the results of univariate and multivariate logistic regression obtained after adjusting for possible confounders. In univariate logistic regression analysis, it was confirmed that the patients in the 3rd and 4th quartiles of the PC ratio showed a higher 90-day mortality rate than the patients in the 1st quartile, and the patients in the 2nd quartile showed an insignificant increase. In addition, multivariate logistic regression analysis adjusted for age, sex, medical history, and laboratory results (eg glucose, neutrophils (%), lymphocytes (%), monocytes (%), and fibrinogen) showed similar results.

Univariate and Multivariate Logistic Regression of the Association Between PC Rate and Short-Term (90-Day) Mortality PC ratio quintiles Univariate Multivatiate ^One† Multivariate ^2§ OR (95% CI) P value OR (95% CI) P value OR (95% CI) P value First quartile One - One - One - Second quartile 1.56 (0.60-4.05) 0.358 1.59 (0.61-4.13) 0.350 1.47 (0.62-4.20) 0.440 Third quartile 2.49 (1.01-6.15) 0.048 ^* 2.56 (1.04-6.43) 0.046* 2.54 (0.95-5.91) 0.048 ^* Four quartiles 4.52 (1.91-10.70) 0.001 ^* 4.89 (1.98-11.31) < 0.001 ^* 4.10 (1.73-9.80) 0.002 ^*

* P value < 0.05 indicates statistical significance.

† Adjusted for age, sex, history of hypertension, diabetes, atrial fibrillation, heart failure, coronary artery occlusive disease and malignancy.

§ Adjusted for age, sex, history of hypertension, diabetes, atrial fibrillation, heart failure, coronary occlusive disease, malignancy, and laboratory findings.

It was confirmed that the survival rate at 90 days after hospitalization had an inverse correlation with the quartile of the PC ratio (p = 0.001 p). In addition, the proportion of non-survivors who died 7 days after admission was the highest in the fourth quartile (Table 6).

As a result of additional analysis of the ratio of non-survivors on the 90th day by gender, it was confirmed that there was no statistical significance. In the result of analyzing the cause of death, it was confirmed that there was no significant difference according to the quartile of the PC ratio, even when divided into neurological and non-neurological causes.

Mortality for PC rate quartiles Characteristic No. (%) Q1 Q2 Q3 Q4 P value 90-day mortality Survival 74 (89.2) 72 (85.7) 66 (79.5) 56 (67.5) 0.001 ^* Non-survival 9 (10.8) 12 (14.3) 17 (20.5) 27 (32.5) Gender difference Male (Total death) 5 (6.0) 6 (7.2) 11 (13.2) 20 (24.1) 0.223 (Neurological) 2 (2.4) 1 (1.2) 3 (3.6) 9 (10.8) Female (Total death) 4 (4.8) 6 (7.2) 6 (7.2) 7 (8.4) (Neurological) 0 (0.0) 4 (4.8) 3 (3.6) 4 (4.8) Cause of death Neurological event 2 (2.4) 5 (6.0) 6 (7.2) 13 (15.7) 0.187 Pneumonia 2 (2.4) 2 (2.4) 3 (3.6) 3 (3.6) Sepsis 2 (2.4) 0 (0.0) 3 (3.6) 7 (8.4) Cardiac event 2 (2.4) 2 (2.4) 2 (2.4) 1 (1.2) Other or unknown 1 (1.2) 3 (3.6) 3 (3.6) 3 (3.6) Length of survival Died 0-7 days 2 (2.4) 3 (3.6) 2 (2.4) 15 (18.1) 0.008 ^* Died 8-15 days 3 (3.6) 2 (2.4) 4 (4.8) 4 (4.8) Died 16-30 days 3 (3.6) 3 (3.6) 5 (6.0) 4 (4.8) Died 31-60 days 0 (0.0) 3 (3.6) 5 (6.0) 3 (3.6) Died 61-90 days 1 (1.2) 1 (1.2) 1 (1.2) 1 (1.2)

Kaplan-Meier survival estimates for each quartile of PC ratio are shown in FIG. 2 . In addition, the survival rate was found to have a significant and negative correlation with the quartile of the PC ratio (p <0.001).

The above results suggest that the PC ratio is positively correlated with short-term (90-day) mortality in ischemic stroke patients, suggesting that the PC ratio can be used as a marker for predicting mortality in ischemic stroke patients.

3. Conclusion

In the analysis of the ROC curve in this study, the parameter did not show an AUC value higher than 0.8. However, PCT showed the highest AUC value among them, and the PC ratio showed the highest AUC value in each combination of markers. Therefore, this experiment focused on the ability of PCT and CRP as prognostic markers in ischemic stroke. As a result, it was confirmed that non-survivors had a much higher proportion of patients with abnormal PCT concentrations than survivors, and that the higher the PC quartile, the higher the correlation with short-term (90-day) mortality.

Therefore, the PC ratio can be used as a useful blood marker for predicting mortality from ischemic stroke, and can be used as a screening tool for new substances for short-term mortality assessment of stroke patients.

Claims (10)

delete delete An informational method for predicting mortality within 90 days from ischemic stroke comprising the following steps:
(1) measuring procalcitonin (PCT) concentration and c-reactive protein (CRP) concentration from a blood sample isolated from a subject;
(2) calculating a ratio of PCT concentration to CRP concentration (PC ratio) from the measured PCT concentration and CRP concentration; and
(3) If the calculated PC ratio is 19.7×10 ^-6 or higher, it is determined that there is a possibility of death within 90 days due to ischemic stroke.
4. The method of claim 3, wherein the PCT concentration and the CRP concentration are protein concentrations.
The method of claim 3, wherein the PC ratio is a value obtained by dividing the PCT concentration by the CRP concentration.
6. The method of claim 5, wherein the PCT concentration is in ng/mL and the CRP concentration is in mg/L.
delete delete A reagent set that specifically measures the concentration of biomarkers including procalcitonin (PCT) and c-reactive protein (CRP) in a blood sample from a subject and 90 days from an ischemic stroke from a subject As a diagnostic kit for providing information for predicting mortality within 90 days due to ischemic stroke, comprising instructions for using the diagnostic kit for providing information for predicting mortality within
The above instructions calculate the ratio (PC ratio) of the PCT concentration to the CRP concentration from the measured PCT concentration and CRP concentration, and if the calculated PC ratio is 19.7×10 ^-6 or higher, the possibility of death within 90 days due to ischemic stroke exists. A diagnostic kit described as being determined.
The diagnostic kit according to claim 9, wherein the reagent measures the protein concentration.

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