Comparison of whole blood interleukin-8 and plasma interleukin-8 as a predictor for sepsis in postoperative patients

IL-8 (CXCL8) Correlations with Psychoneuroimmunological Processes and Neuropsychiatric Conditions

Interleukin-8 (IL-8/CXCL8), an essential CXC chemokine, significantly influences psychoneuroimmunological processes and affects neurological and psychiatric health. It exerts a profound effect on immune cell activation and brain function, suggesting potential roles in both neuroprotection and neuroinflammation. IL-8 production is stimulated by several factors, including reactive oxygen species (ROS) known to promote inflammation and disease progression. Additionally, CXCL8 gene polymorphisms can alter IL-8 production, leading to potential differences in disease susceptibility, progression, and severity across populations. IL-8 levels vary among neuropsychiatric conditions, demonstrating sensitivity to psychosocial stressors and disease severity. IL-8 can be detected in blood circulation, cerebrospinal fluid (CSF), and urine, making it a promising candidate for a broad-spectrum biomarker. This review highlights the need for further research on the diverse effects of IL-8 and the associated implications for personalized medicine. A thorough understanding of its complex role could lead to the development of more effective and personalized treatment strategies for neuropsychiatric conditions.

Endothelial progenitor cells in the host defense response

Extensive injury of endothelial cells in blood vasculature, especially in the microcirculatory system, frequently occurs in hosts suffering from sepsis and the accompanied systemic inflammation. Pathological factors, including toxic components derived from invading microbes, oxidative stress associated with tissue ischemia/reperfusion, and vessel active mediators generated during the inflammatory response, are known to play important roles in mediating endothelial injury. Collapse of microcirculation and tissue edema developed from the failure of endothelial barrier function in vital organ systems, including the lung, brain, and kidney, are detrimental, which often predict fatal outcomes. The host body possesses a substantial capacity for maintaining vascular homeostasis and repairing endothelial damage. Bone marrow and vascular wall niches house endothelial progenitor cells (EPCs). In response to septic challenges, EPCs in their niche environment are rapidly activated for proliferation and angiogenic differentiation. In the meantime, release of EPCs from their niches into the blood stream and homing of these vascular precursors to tissue sites of injury are markedly increased. The recruited EPCs actively participate in host defense against endothelial injury and repair of damage in blood vasculature via direct differentiation into endothelial cells for re-endothelialization as well as production of vessel active mediators to exert paracrine and autocrine effects on angiogenesis/vasculogenesis. In recent years, investigations on significance of EPCs in host defense and molecular signaling mechanisms underlying regulation of the EPC response have achieved substantial progress, which promotes exploration of vascular precursor cell-based approaches for effective prevention and treatment of sepsis-induced vascular injury as well as vital organ system failure.

The impact of interleukin serum levels on the prognosis of patients undergoing venoarterial extracorporeal membrane oxygenation

Extracorporeal life support is increasingly used in the treatment of patients presenting with cardiogenic shock or in need of cardiopulmonary resuscitation. Identifying therapeutic targets and factors associated with the prognosis are highly desirable. The present study analyzed the impact of interleukin 6 and 8 on the outcome of patients undergoing venoarterial extracorporeal membrane oxygenation (VA ECMO). Interleukin 6 and 8 serum levels of 329 patients were analyzed prior to, on days 1 and 5 of VA ECMO therapy. Interleukin 6 and 8 serum levels of surviving and nonsurviving patients were compared. At time points with significant differences, receiver operating characteristics and cutoff levels were analyzed to determine the prognostic value of interleukin serum levels. Survival analysis was performed to compare patients above and below cutoff levels. Interleukin 6 serum levels were significantly elevated in nonsurviving patients prior to VA ECMO initiation. Interleukin 6 and 8 serum levels in nonsurviving patients were significantly elevated on day 1 of VA ECMO. Receiver operating characteristics analysis revealed significant prognostic impact of interleukin 6 and 8 on day 1 of VA ECMO (AUC 0.70 and 0.72). Survival analysis comparing patients above and below the cutoff showed a 1-year survival of 32.6% for IL6 and 20.8% for IL8 above, as well as 66.9% for IL6 and 61.9% for IL8 below the cutoff (P < .05). Interleukin 6 and 8 serum levels demonstrated prognostic value early in VA ECMO therapy. The technical applicability of interleukin reduction raises interest in interleukins 6 and 8 as therapeutic targets.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

Searching for predictors of surgical complications in critically ill surgery patients in the intensive care unit: a review

We reviewed the use of the levels of C-reactive protein, lactate and procalcitonin and/or the Sequential Organ Failure Assessment score to determine their diagnostic accuracy for predicting surgical complications in critically ill general post-surgery patients. Included were all studies published in PubMed from inception to July 2013 that met the following inclusion criteria: evaluation of the above parameters, describing their diagnostic accuracy and the risk stratification for surgical complications in surgical patients admitted to an intensive care unit. No difference in the Sequential Organ Failure Assessment scores was seen between patients with or without complications. The D-lactate levels were significantly higher in those who developed colonic ischemic complications after a ruptured abdominal aortic aneurysm. After gastro-intestinal surgery, contradictory data were reported, with both positive and negative use of C-reactive protein and procalcitonin in the diagnosis of septic complications. However, in trauma patients, the C-reactive protein levels may help to discriminate between those with and without infectious causes. We conclude that the Sequential Organ Failure Assessment score, lactate concentration and C-reactive protein level have no significant predictive value for early postoperative complications in critically ill post-surgery patients. However, procalcitonin seems to be a useful parameter for diagnosing complications in specific patient populations after surgery and/or after trauma.

Very early posttraumatic serum alterations are significantly associated to initial massive RBC substitution, injury severity, multiple organ failure and adverse clinical outcome in multiple injured patients

Background

Multiple severe trauma frequently leads to massive dysbalances of the human immune system. This phenomenon is known as "Systemic Inflammatory Response Syndrome (SIRS)". SIRS is connected to multiple organ failure and thereby entails higher morbidity and mortality in trauma patients. Pro-and anti-inflammatory cytokines such as Il-6, Il-8 and Il-10 seem to play a superior role in the development of SIRS. Several studies support the hypothesis that the very early cytokine release pattern determines the patients' subsequent clinical course. Most data about interleukins in trauma patients however refer to serum concentrations assessed sometime in the first 24 h, but there is only little information about release dynamics in a small-meshed time frame in the very initial post-trauma period.

Patients and methods

58 multiple injured patients (Injury Severity Score > 16 points) were included. Blood samples were drawn on patient admission (not later then 90 minutes after trauma) and at 6 h, 12 h, 24 h, 48 h and 72 h. Il-6, Il-8 and Il-10 were measured using an automated chemiluminescence assay (IMMULITE, Siemens Healthcare Diagnostics GmbH). Interleukin levels were correlated to distinct epidemiological and clinical parameters.

Results

Interleukin serum concentrations are thoroughly elevated after trauma. Patients with haemorrhagic shock and consecutive massive RBC substitution (n = 27) exhibit higher Il-6, Il-8 and Il-10 levels as compared to patients with minor RBC transfusion extent (n = 31). Interleukin levels also differentiate patients with MOF (n = 43) from such without MOF (n = 15) already at the earliest post trauma time (90 minutes). Il-6, Il-8 and Il-10 concentrations also significantly distinguish patients with adverse outcome (n = 11) from such with favourable outcome (n = 47). Exclusively Il-10 has significant correlation to injury severity (ISS > 35).

Conclusion

The current study presents an image of the serum Il-6, 8 and 10 releases in multiple trauma patients in the very early post-trauma period. We could thereby demonstrate that interleukin levels can clearly differentiate the presence of hemorrhagic shock and subsequent massive blood product substitution, the development of multiple organ failure and clinical outcome. No significant connection to age, gender and brain injury could be detected. Most importantly, changes in interleukin levels can be observed in the very early posttraumatic phase, at the earliest 90 minutes after trauma.