Systemic Immune Inflammation Index as a Predictor of Disease Severity in Tetanus Patients

doi:10.21203/rs.3.rs-3966154/v1

Objective

This study aimed to analyze the predictive value of the systemic immune inflammation index (SII) for the severity of disease in tetanus patients.

Methods

Clinical data of 34 tetanus patients admitted to the Second People's Hospital of Fuyang from January 2019 to December 2022 were analyzed. Based on whether patients received intensive care unit (ICU) treatment after admission, the patients were divided into ICU and non-ICU groups. The diagnostic value of SII for the severity of tetanus was assessed.

Results

Among the 34 patients, 18 (52.90%) were classified into the ICU group, and 16 (47.10%) into the non-ICU group. There were statistically significant differences in white blood cell count, platelet count, neutrophil count, and SII between the two groups (P < 0.05). Logistic regression analysis revealed that SII was a risk factor for tetanus patients requiring ICU treatment. The area under the curve (AUC) for SII predicting ICU treatment in tetanus patients was 0.896 (95% CI 0.790–1.000, P < 0.001).

Conclusion

The SII can serve as an objective predictive indicator for tetanus patients requiring ICU treatment.

Health sciences/Diseases/Infectious diseases

Health sciences/Medical research/Biomarkers

Tetanus

Severity

Risk factors

Tetanus is an infectious disease caused by Clostridium tetani, characterized by persistent, tonic contractions of skeletal muscles and paroxysmal spasms in patients[1-2]. Due to the nonspecific early clinical symptoms of tetanus, patients are typically initially admitted to general wards, and transfer to the intensive care unit (ICU) for treatment occurs when the condition becomes severe, leading to delayed intervention and posing a threat to patients' lives. Therefore, guidelines emphasize the need for more graded schemes and clinically relevant studies on prognosis[2-3].

The Systemic Immune Inflammation Index (SII) is a novel immunoinflammatory marker that integrates peripheral blood platelet, neutrophil, and lymphocyte counts. It is considered an effective indicator reflecting the systemic immune-inflammatory status and prognosis, with the formula: Neutrophil count (×10⁹/L) × Platelet count (×10⁹/L) / Lymphocyte count (×10⁹/L)[4]. Studies have shown that SII has excellent clinical value in assessing the prognosis of patients with rheumatoid arthritis, cancer, infectious diseases, and other conditions[5-8]. This study retrospectively analyzed the clinical treatment of 34 tetanus patients, exploring the clinical value of SII in predicting the severity of disease in tetanus patients. The findings are reported as follows.

1.1 Study Subjects

A retrospective review was conducted on tetanus patients admitted to the Second People's Hospital of Fuyang from January 2019 to December 2022. Inclusion criteria were as follows: ① Patients clinically diagnosed with tetanus; ② Complete clinical data. Exclusion criteria were: ① Discharge or death within 24 hours of admission; ② Incomplete clinical data. A total of 34 patients were included, comprising 22 males (64.70%) and 12 females (35.30%), with an average age of (62.06±12.88) years.

1.2 Data Collection

Based on whether patients received intensive care unit (ICU) treatment after admission, the 34 patients were divided into ICU and non-ICU groups. Data recorded included patient gender, age, underlying diseases, Ablett classification, time from onset to medical treatment, total hospital stay, white blood cell count, platelet count, total bilirubin, creatinine, creatine kinase, creatine kinase isoenzyme, neutrophil count, lymphocyte count, and the Systemic Immune Inflammation Index (SII) calculated based on blood routine results.

1.3 Statistical Analysis

Statistical analysis was performed using SPSS 22.0. Continuous data were expressed as "±s" and analyzed using independent sample t-tests. Categorical data were presented as case numbers (n) and percentages (%) and analyzed using χ² tests. Binary logistic regression analysis was used for multifactor analysis. Receiver Operating Characteristic (ROC) curves were drawn to analyze the diagnostic value of SII for the severity of tetanus, with the cutoff value determined as the point with the maximum Youden index. A significance level of P<0.05 indicated statistical significance.

2.1 Univariate Analysis of Tetanus Patients Receiving ICU Treatment

Among the 34 patients, 18 (52.90%) were categorized into the ICU group, and 16 (47.10%) into the non-ICU group based on whether they received ICU treatment. There were no statistically significant differences between the two groups in terms of age, gender, underlying diseases, time from onset to medical treatment, total bilirubin, creatinine, creatine kinase, creatine kinase isoenzyme, and lymphocyte count (P>0.05). However, statistically significant differences were observed in white blood cell count, platelet count, neutrophil count, and the Systemic Immune Inflammation Index (SII) between the two groups (P<0.05). Refer to Table 1 for details.

Table 1: Univariate Analysis of Tetanus Patients Receiving ICU Treatment

Variable		ICU Group（n=18）	Non-ICU Group（n=16）	c²/ t Value	P Value
Gender［n(%)］				0.216	0.642
	Male	11（61.11）	11（68.75）
	Female	7（38.89）	5（31.25）
Underlying Diseases［n(%)］				2.862	0.091
	Present	4（22.22）	8（50.00）
	Absent	14（77.78）	8（50.00）
Age (years)		62.22±12.55	61.88±13.65	0.077	0.939
Time from Onset to Treatment (days)		2.78±1.66	3.88±3.59	-1.164	0.253
White Blood Cell Count（×10⁹∕L)		10.00±3.14	6.55±1.99	3.776	0.001
Platelet Count（×10⁹∕L)		284.28±81.61	219.13±68.19	2.508	0.017
Total Bilirubin（×10⁹∕L)		15.33±5.36	16.37±9.54	-0.398	0.693
Creatinine（×10⁹∕L)		62.39±11.88	63.94±11.11	-0.393	0.698
Creatine Kinase（×10⁹∕L)		334.33±205.73	222.75±207.19	1.573	0.125
Creatine Kinase Isoenzyme（×10⁹∕L)		21.11±10.77	18.50±16.33	0.556	0.582
Neutrophil Count（×10⁹∕L)		8.16±3.36	4.27±1.84	4.114	<0.001
Lymphocyte Count（×10⁹∕L)		1.45±0.78	1.61±0.58	-0.649	0.521
SII		2222.15±2197.33	624.84±349.71	3.041	0.007

2.2 Multivariate Analysis of Tetanus Patients Receiving ICU Treatment

Building upon the results of univariate analysis, variables with statistically significant differences, including white blood cell count, platelet count, neutrophil count, and the Systemic Immune Inflammation Index (SII), were selected as independent variables. Binary logistic regression analysis was conducted with the acceptance of ICU treatment as the dependent variable. The results indicated that SII is a risk factor for tetanus patients requiring ICU treatment. Refer to Table 2 for details.

Table 2: Multivariate Analysis of Tetanus Patients Receiving ICU Treatment

Variable	β	Wald	P Value	OR	95% C.I.for OR
Variable	β	Wald	P Value	OR	Lower	Upper
SII	0.003	4.029	0.045	1.003	1.000	1.006
Neutrophil Count	0.673	3.399	0.065	1.961	0.958	4.010
Constant	-6.844	6.282	0.012	0.001

2.3 Predictive Value of SII for Tetanus Patients Receiving ICU Treatment

The SII demonstrated significant predictive value for tetanus patients requiring ICU treatment, with an area under the curve (AUC) of 0.896 (95% CI 0.790–1.000, P<0.001). At the optimal cutoff value of 892.98, the sensitivity of SII in predicting tetanus patients requiring ICU treatment was 83.3%, with a specificity of 87.5%. Refer to Figure 1 for the ROC curve illustrating the predictive performance of SII.

Figure 1: ROC Curve of SII for Predicting ICU Treatment in Tetanus Patients

2.4 Prognosis

The prognosis of tetanus patients varied based on the initial treatment location. Among those initially treated in the ICU, 6 patients were admitted, 5 were cured, and 1 patient opted for treatment discontinuation. For patients transferred from general wards to the ICU, 12 were admitted, 9 were cured, and 3 patients chose to discontinue treatment. One patient initially admitted to a general ward, who deteriorated but refused transfer to the ICU, opted for treatment discontinuation. All 15 patients continuously treated in general wards were cured. Refer to Table 3 for a comparison of the cure rates among different treatment groups.

Table 3: Comparison of Cure Rates in Different Initial Treatment Settings

Group	Total Number (cases)	Discontinuation/Death (cases)	Cured (cases)	Cure Rate (%)
First ICU Treatment	6	1/0	5	83.33
Transfer to ICU Treatment	12	3/0	9	75.00
Continuous General Ward Treatment	15	0/0	15	100.00
Total	33	4/0	29	87.88

Tetanus is a vaccine-preventable disease that remains prevalent in many low- and middle-income countries, posing ongoing challenges[9-10]. Studies suggest that early initiation of intensive care and nursing for severe and very severe (Ⅲ/Ⅳ grade) patients can reduce the mortality rate among tetanus patients[11-12]. Therefore, predicting the severity of tetanus is crucial for patient treatment and prognosis.

Currently, the assessment of tetanus severity often relies on the Ablett grading system[2,13]. In this study, 13 patients initially admitted to general wards based on Ablett grading later required transfer to the ICU as their conditions worsened. Some patients exhibited mild symptoms upon admission and deteriorated after being admitted to general wards, leading to delayed ICU treatment. Cai Miaotian et al.[14] highlighted the limitations of the Ablett grading system, emphasizing its subjective nature and lack of quantitative precision. In contrast, the Systemic Immune Inflammation Index (SII) can predict the severity of the disease upon admission, guiding ICU admission and allowing for early intervention to prevent progression to severe conditions. In this study, the AUC of the ROC curve for SII predicting ICU treatment in tetanus patients was 0.896, demonstrating high sensitivity and specificity.

In summary, the SII is a convenient and cost-effective indicator that can serve as an objective predictor for tetanus patients requiring ICU treatment. However, due to the small sample size in this study, further confirmation through larger-scale research is warranted. Additionally, the lack of dynamic monitoring of SII changes during hospitalization and the absence of an in-depth exploration of the correlation between SII changes and the severity of the patient's condition require further investigation in future studies.

Ethics Statement

The studies involving human participants were reviewed and approved by Ethics Committee of No.2 People's Hospital of Fuyang City(20231210056).The patients/participants provided their written informed consent to participate in this study. All methods were implemented in accordance with relevant guidelines and regulations.

Author Contribution

Dai Cheng and Huang Jizheng wrote the main manuscript text.Sun Wei,Li Liang,Han Guolei and Yang Hao prepared Table 1-3 and figures 1. All authors reviewed the manuscript.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author, upon reasonable request.

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No competing interests reported.

Systemic Immune Inflammation Index as a Predictor of Disease Severity in Tetanus Patients

Status:

Version 1

Abstract

Objective

Methods

Results

Conclusion

Figures

Introduction

Materials and Methods

Results

Discussion

Declarations

Ethics Statement

Author Contribution

Data Availability Statement

References

Additional Declarations

Status:

Version 1