Sepsis: A Critical Challenge for Global Health

Sepsis is a severe condition caused by an uncontrolled immune response in the body, leading to extensive tissue and organ damage. Patients with sepsis often experience widespread inflammation, multi-organ dysfunction, and, in severe cases, septic shock. Without prompt diagnosis and treatment, this condition can be fatal. Due to its high global morbidity and mortality rates, early diagnosis and appropriate management are crucial to improving clinical outcomes.  

A promising biomarker in the assessment of sepsis is the Systemic Immune-Inflammation Index (SII). It combines several biological parameters to reflect the balance between immune response and inflammation in the body. Calculated using platelet, neutrophil, and lymphocyte levels, it helps predict disease severity and estimate the prognosis of septic patients, particularly regarding short-term mortality.  

This meta-analysis explores the relationship between elevated SII and short-term mortality in sepsis patients. The objective is to determine whether SII can serve as an indicator to identify high-risk patients more quickly and predict the risk of death within days and weeks after hospital admission. This biomarker could enable more targeted management and earlier interventions.  

SII as an Indicator of Mortality in Sepsis Patients?  

This study is based on the analysis of 9 patient cohorts with sepsis, totaling 25,626 participants. The cohorts include patients of various age groups, sexes, and comorbidities to ensure representativeness and minimize selection bias. SII was measured upon hospital admission, while mortality was tracked over a 90-day period following admission.  
The results show that a high SII is associated with an increased risk of short-term mortality in sepsis patients. The likelihood of death was higher among patients with a high SII (51%) compared to those with a low SII. Subgroup analysis revealed that this association was more pronounced in patients under 67 years of age (RR: 1.72) compared to those over 67 (RR: 1.39). Inflammation in younger patients may have a more severe impact on clinical outcomes.  

SII: A Reliable Tool for Predicting Short-Term Mortality  

The analyses demonstrate that SII is a reliable and accessible indicator for predicting short-term mortality in sepsis patients, regardless of sex, follow-up duration, or measurement method. Thanks to its simplicity and the ease of measuring its components in standard laboratory tests, this biomarker could improve risk stratification in clinical settings, enabling more targeted management and earlier interventions.  

Future studies should investigate the role of SII in the long-term monitoring of sepsis patients to better understand its capacity to predict complications after the acute phase. It would also be important to evaluate the impact of treatments targeting the components of SII, such as platelets, neutrophils, and lymphocytes, to determine if their modulation can improve long-term outcomes for these patients. This could contribute to better sepsis management and reduce mortality as well as long-term sequelae.