| Abstract |
Background
Sepsis is defined as a life-threatening syndrome of organ dysfunction caused by a dysregulated host response to infection. Necroptosis, which is a programmed mechanism of cell death, plays an important role in the septic process. This process is controlled by Receptor-Interacting Protein Kinases 1 and 3 that interact with receptors 1 and 3 (RIPK1 and RIPK3) and by Mixed-Lineage Kinase Domain-Like Pseudokinase (MLKL)
Objective
The study's main aim is to investigate the expression of necroptosis and apoptotic caspase 8 proteins in patients with sepsis, compared to patients with trauma or heart disease and healthy controls. In addition, to compare the results of these measurements with clinical and laboratory markers of disease severity and outcome, and to compare the results of measurements and analyses between children and adults.
Methods
This is a prospective single-centre study measuring necroptosis proteins in pediatric and adult sepsis patients (32 children and 56 adults) hospitalized in intensive care units. We recorded whether patients met the criteria for sepsis or SIRS and other laboratory markers confirming evidence of inflammation and infection. The expression of necroptosis and apoptotic caspase 8 proteins was measured by enzyme-linked immunosorbent assay (ELISA). Healthy adults and children (controls) were selected as control groups. Patients with chronic diseases, immunodeficiencies, malignancies and those receiving immunosuppressive and immunomodulatory treatment were excluded. The appropriate statistical tests of the SPSS 26 statistical package were used for statistical analysis of the data.
Results
Data from 88 patients were analyzed, distributed as follows in terms of study groups: with sepsis 26.1%, with trauma or surgery (SIRS) 33%, with heart disease 21.6%, and healthy 19.3%. Fifty-six adults (63.6%) and 32 children (36.4%) were included in the study. The major necroptosis expressing proteins RIPK-1 and RIPK-3 were increased in patients with sepsis compared to the other groups, although only RIPK-1 reached statistical significance; in contrast, MLKL showed no significant difference in either pediatric or adult patients. Caspase 8 was decreased in sepsis patients compared to the other groups (p<0.001). The major inflammatory interleukins stimulated through the necroptosis pathway IL-1b, and IL-18 were significantly increased in patients compared to healthy subjects, especially in the sepsis group concerning the IL-18. The following necroptosis-related biomarkers were significantly associated with the duration of ICU hospitalization; RIPK-1 (rs=0.5, p<0.001), IL-1b (rs=0.43, p<0.001), (rs=0.48, p<0.001) and negatively caspase-8 (rs=-0.24, p=0.028); MLKL protein did not register a significant difference between groups in adult and pediatric patients. Biomarkers RIPK-1, IL-18 and A20 best predicted the probability of a diagnosis of sepsis or septic shock in the ICU and suppression of caspase 8.
Conclusion The expression of RIPK1, RIPK3, IL-1b, IL-18 and A20 proteins is increased in patients with sepsis. This fact demonstrates the direct correlation of biomarkers of necroptosis with sepsis. IL-1b increased in sepsis in children, in infarction or postoperatively in adults. This confirms that the inflammatory interleukins, IL-1b and IL-18 are stimulated through the necroptosis pathway. Caspase 8 is decreased in patients with sepsis; thus, its inhibition and activation of necroptosis in patients with sepsis is confirmed. Significant predictive ability for the diagnosis of sepsis or septic shock is shown to be expressed by RIPK-1, IL-18 and A20, while RIPK-1 is positively correlated with the duration of hospitalization and caspase-8 negatively correlated with the duration of hospitalization. Collectively, these results lead us to conclude the important role of necroptosis as a mechanism of cell death in sepsis and its further investigation may add potential therapeutic interventions in sepsis.
|
Collections
