Enhanced attachment and elastase-releasing capacity of neutrophils after surgery

Perioperative corticosteroids for reducing postoperative complications following esophagectomy: an updated systematic review and meta-analysis

BACKGROUND

This updated systematic review and meta-analysis aims to evaluate the efficacy and safety of perioperative corticosteroid administration versus placebo for esophageal cancer patients following scheduled esophagectomy.

METHODS

We searched databases through June 30, 2023. We included articles on randomized controlled trials (RCTs) comparing perioperative corticosteroid administration with placebo in esophageal cancer patients with esophagectomy. The outcomes were the death rate during hospitalization, length of hospital stay, and short-term complications. Risk ratios (RRs) and corresponding 95% confidence interval (CIs) for each estimated effect size were applied for dichotomous outcomes, and the mean difference (MD) and corresponding 95% CIs for each estimated effect size were applied for continuous outcomes. We used GRADE to evaluate the quality of each of the outcome and the level of recommendations.

RESULTS

Nine RCTs with 508 participants were included in this study. Severe outcomes, including the length of hospital stay, leakage, mortality during the hospitalization period in the corticosteroid group was comparable to that in the control group, but positive effects of corticosteroid administration were observed on the length of intensive care unit stay (MD -3.1, 95% CI - 5.43 to - 0.77), cardiovascular disorders (RR 0.44, 95% CI 0.21-0.94) and other general complications (RR 0.49, 95% CI 0.29-0.85).

CONCLUSIONS

Peri-operative intravenous corticosteroid administration may reduce cardiovascular disorders, other general complications and the length of ICU stay without carrying severe outcomes. More high quality RCTs are warranted to further investigate the effects of corticosteroids on postoperative mortality and complications for esophageal cancer patients with esophagectomy.

SYSTEMATIC REVIEW REGISTRATION

Cochrane, registration number: 196.

The role of superoxide anions in the development of distant tumour recurrence

We hypothesise that reactive oxygen species (ROS) released from activated polymorphonuclear leucocytes during surgery play a crucial role in enhanced tumour recurrence seen after surgery. Therefore, the effect of ROS on adhesion of tumour cells to microvascular endothelium in a reproducible human in vitro model was studied. Preincubation of microvascular endothelial cells with the superoxide anion producing xanthine–xanthine oxidase complex significantly increased adhesion of the human colon carcinoma cells HT29 (167% vs control, P<0.01), Caco2 (164% vs control, P<0.01) and of the pancreas carcinoma cells PanC1 (180% vs control, P<0.01). Addition of the antioxidant enzymes superoxide dismutase or catalase significantly decreased tumour cell adhesion (P<0.01). Exposure of endothelial cells to superoxide anions increased the apoptotic rate to 7.9 times the normal rate. Additionally, exposure increased expression of the endothelial adhesion molecules E-Selectin, ICAM-1, and VCAM-1 of maximally 170% vs control (P<0.01). In conclusion, this study shows that superoxide anions promote the adherence of tumour cells to the microvasculature by inducing endothelial apoptosis that subsequently induces the expression of various adhesion molecules for tumour cells. This indicates that by tackling the production of ROS preventing tumour recurrence at distant sites might be feasible.

Prospective randomized study of steroids in the prevention of ischaemic injury during hepatic resection with pedicle clamping

BACKGROUND

The major drawback of hepatic pedicle clamping is ischaemia-reperfusion injury with impairment of liver function. Perioperative steroid administration has been advocated to reduce liver damage. The aim of this prospective, randomized study was to determine whether steroid administration can reduce liver injury and improve short-term outcome.

METHODS

Fifty-three patients undergoing liver resection were randomized to a steroid group (group 1) or to a control group (group 2); patients in group 1 received methylprednisolone 30 mg/kg 30 min before liver resection whereas those in group 2 did not. Serum levels of interleukin (IL) 6, total bilirubin, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and prothrombin time (PT) were measured. Length of stay, and type and number of complications were recorded.

RESULTS

Serum IL-6 levels were significantly lower in the steroid group than in the control group 24 h after surgery. Steroid administration significantly modified AST, ALT and PT levels only in patients with chronic liver disease. Overall and lung-related morbidity were not significantly different between the two groups.

CONCLUSIONS

Steroid administration suppresses serum IL-6 levels, but has no effect on short-term outcome.

The influence of homologous blood transfusion on immunity and clinical outcome in aortic surgery

OBJECTIVES

To evaluate the influence of homologous blood transfusion on immune responses and post-operative morbidity in aortic surgery.

DESIGN

Analysis of the effects of homologous blood transfusion in 128 patients in a prospective randomised trial evaluating homologous and autologous blood transfusion in aortic surgery.

MATERIALS AND METHODS

Blood sampled before and at five times after surgery was assayed for C-reactive protein (CRP), neutrophil elastase, TNF-alpha and IL-6. Transfusions, morbidity and mortality were recorded; factors associated with poor outcome were identified by logistic regression.

RESULTS

homologous transfusion during surgery was required in 32 patients and precipitated an increase in neutrophil elastase (p=0.008) and TNF-alpha (p=0.015) but not IL-6 and CRP. Elastase peaked early in transfused patients at 41.27 (13.92-52.11) Deltang/ml by 2 h compared to a peak of 21.51 (10.64-31.13) Deltang/ml by 24 h in those who were not transfused. TNF-alpha peaked at 1.2 (0-4.33) Deltapg/ml by wound closure in transfused patients and at -0.1 (-2.05-2.52) Deltapg/ml by 2 h without transfusion. Intra-operative homologous transfusion was associated with increased mortality (p=0.01) and prolonged intensive care stay (p=0.03). Mortality increased with age (p=0.003) and was inversely related to the CRP peak (p=0.007). Prolonged surgery predicted post-operative complications (p=0.025).

CONCLUSION

Homologous transfusion increased the inflammatory response to aortic surgery and was associated with mortality.

Transcription factor NF kappa B expression and postsurgical organ dysfunction

OBJECTIVE

To examine the role of neutrophil NF kappa B activation in organ dysfunction after major surgery.

SUMMARY BACKGROUND DATA

NF kappa B is a transcription factor involved in the signal transduction of many stimuli that may participate in the pathogenesis of sepsis and resultant multiple organ dysfunction syndrome (MODS). It may therefore be a potential target for modulation in the reduction of postsurgical MODS.

METHODS

Twenty-five patients undergoing major vascular surgery (thoracoabdominal aortic aneurysm repair) were studied. Perioperative levels of neutrophil NF kappa B, CD11b, and glutathione were measured. In vitro inhibition experiments using NF kappa B inhibitors were also performed.

RESULTS

No differences in clinical parameters were apparent before surgery between the patients who subsequently developed MODS and those who did not. However, there was a significant difference in preoperative levels of NF kappa B between the patients who developed postoperative organ dysfunction and those who did not. There was also a significant preoperative difference between patients who survived surgery and those who did not. Glutathione levels were reduced both in patients who developed MODS and those who did not at the onset of surgery. NF kappa B inhibitors suppressed patient plasma-stimulated NF kappa B activation in healthy neutrophils.

CONCLUSIONS

Preoperative neutrophil NF kappa B status may be a marker of postoperative outcome after major surgery, and therapy aimed at attenuating neutrophil NF kappa B activation may reduce postoperative sepsis and organ dysfunction.

Plasma concentration of cytokine antagonists in patients with infection following liver resection

BACKGROUND

The interactions between endogenous cytokine antagonists, surgical injury and perioperative infection are poorly understood.

METHODS

Perioperative plasma concentrations of soluble tumour necrosis factor receptor p55 (STNFR p55), interleukin (IL) 1 receptor antagonist (IL-1ra) and IL-6 were measured by immunoassay in 29 consecutive patients undergoing liver resection.

RESULTS

Plasma concentrations of STNFR p55, IL-1ra and IL-6 showed a striking increase immediately after operation (day 0) and on postoperative day 1. STNFR p55 concentrations correlated significantly with operating time (P< 0.05); IL-1ra levels with operating time, blood loss and weight of resected liver (P < 0.05); and IL-6 concentrations with operating time and blood loss (P< 0.05). Eight of the 29 subjects developed postoperative infections, of whom four had positive cultures of enteric organisms. Plasma STNFR p55 and IL-6 concentrations were significantly higher in the infected group than in the uninfected group (P < 0.05). STNFR p55 and IL-6 concentrations on day 0 differentiated between the two groups with a diagnostic accuracy of 79 and 83 per cent respectively.

CONCLUSION

These results suggest that STNFR p55, IL-1ra and IL-6 are produced during operation in response to surgical stress. This production of STNFR p55 and IL-6 may be enhanced further by intraoperative bacterial translocation. Measurement of plasma STNFR and IL-6 concentrations may predict the development of postoperative infectious complications.

Interleukin-6 augments neutrophil cytotoxic potential via selective enhancement of elastase release

BACKGROUND

Interleukin-6 (IL-6) appears to be a reliable marker of disease severity in critically ill patients at risk for inflammatory organ injury such as ARDS and MOF. Debate continues, however, as to whether this pleiotropic cytokine acts principally as a proinflammatory or counterregulatory mediator. Because the polymorphonuclear leukocyte (PMN) is a central effector of inflammatory injury, defining the effects of IL-6 on mechanisms of PMN cytotoxicity may be revealing. Previous investigations of PMN release of reactive oxygen species demonstrate that IL-6 in concert with other mediators may augment cytotoxicity. We hypothesized that IL-6 alone increases PMN cytotoxic potential through selective enhancement of elastase release.

MATERIALS AND METHODS

Isolated human PMNs were incubated with IL-6 in the physiologic range observed in critically ill patients (0.1 to 100 ng/ml) for 10 to 30 min. Selected cells were then activated with fMLP (1 microM). Elastase release was measured by specific cleavage of AAPV-pNA and compared to untreated cells and cells activated with formyl-Met-Leu-Phe (fMLP; 1 microM) alone. To determine if changes in elastase release might be due to IL-6 induced generation of PAF, WEB 2347 (50 microM) was preincubated with selected cells for 20 min. Surface expression of beta 2 integrins was measured by flow cytometry after incubating with labeled antibodies to CD11b and CD18.

RESULTS

IL-6 alone at 100 ng/ml augmented basal elastase release by 116 +/- 41% within 10 min. Doses as low as 0.1 ng/ml stimulated elastase release when the incubation time was increased to 30 min. After 30 min of incubation, IL-6 at all doses examined augmented the elastase release of fMLP-activated cells (increases of 33 to 45%). WEB 2347 preincubation did not block augmentation of elastase release by IL-6 at 10 ng/ml. IL-6 had no effect on surface expression of beta 2 integrins at 10 ng/ml.

CONCLUSIONS

IL-6 alone enhances both basal and fMLP-stimulated elastase release by PMNs. This proinflammatory action on PMNs may help explain the observed correlation between circulating IL-6 levels and inflammatory organ injury.

Visceral ischemia and neutrophil activation in sepsis and organ dysfunction

BACKGROUND

It has previously been shown that a rise in intraoperative neutrophil CD11b expression during supracoeliac cross-clamping is a marker for subsequent development of postoperative organ dysfunction. Prolonged visceral ischemia and increased aneurysm extent are associated with higher risks of morbidity and mortality after TAAA repair. This study investigates the relationship between visceral ischemia and neutrophil activation in sepsis and organ dysfunction following visceral reperfusion.

METHOD

Fifty-one patients undergoing supracoeliac cross-clamping, 5 patients undergoing suprarenal clamping, and 8 patients undergoing infrarenal clamping for repair of aortic aneurysms were studied. Perioperative neutrophil CD11b expression was measured by flow cytometry.

RESULTS

There was significant correlation between visceral clamp time and intraoperative CD11b expression. More extensive aneurysms resulted in increased visceral clamp times and CD11b expression. There were no differences between bypass and non-bypass-assisted surgery with regard to neutrophil expression. There were increased clamp time in patients who developed severe sepsis and postoperative organ dysfunction. Differences in preoperative levels of CD11b expression were observed between groups and high levels of preoperative CD11b expression were observed in patients who died intraoperatively, in type II patients who went on to develop severe sepsis and organ failure, and in patients who developed multiple organ failure rather than single organ failure.

CONCLUSION

Longer periods of visceral ischemia are associated with higher levels of intraoperative CD11b expression, severe sepsis, and organ failure. High preoperative levels of CD11b may identify an "at-risk" subset of patients.

Redox potential measurements of plasma in patients undergoing coronary artery bypass graft and its clinical significance

The apparent redox potentials (Em) of plasma as a marker of oxidant injury during coronary artery bypass graft (CABG) is determined, and their clinical significance is discussed. We measured plasma Em of normal volunteers (n = 20) and samples drawn at different time points from patients undergoing elective CABG (n = 60) directly and by adding 5 microl (20 mM) oxidants or reductants with known redox potential to plasma (95 microl), using a micro Pt/AgCl combination redox electrode. The Em value stays elevated up to 30 min during the surgery, after the administration of protamine it came down toward a more reduced state. Similar changes are seen with the lactate pyruvate ratio. Smaller changes of Em than normal are observed in plasma samples from patients treated with Aprotinin (antiprotease), Carmeda (heparin-coated) circuit and aspirin reflecting their protective effect. Redox potential (Em) measurements appear to be effective and useful in monitoring redox shifts wherever oxidative stress needs to be monitored.

Interleukin-6 in the injured patient. Marker of injury or mediator of inflammation?

OBJECTIVE

The effects of interleukin (IL)-6 in the injured patient are examined in an attempt to clarify the potential pathophysiologic role of IL-6 in the response to injury.

SUMMARY BACKGROUND DATA

Interleukin-6 is an integral cytokine mediator of the acute phase response to injury and infection. However, prolonged and excessive elevations of circulating IL-6 levels in patients after trauma, burns, and elective surgery have been associated with complications and mortality. The mechanistic role of IL-6 in mediating these effects is unclear.

METHODS

A review of current literature is performed to summarize the origins, mechanisms of action, and biologic effects of IL-6 and to characterize the IL-6 response to injury.

RESULTS

Interleukin-6 is a multifunctional cytokine expressed by a variety of cells after a multitude of stimuli, under complex regulatory control mechanisms. The IL-6 response to injury is uniquely consistent and related to the magnitude of the insult. Moreover, the early postinjury IL-6 response correlates with complications as well as mortality.

CONCLUSIONS

Interleukin-6 appears to play an active role in the postinjury immune response, making it an attractive therapeutic target in attempts to control hyperinflammatory provoked organ injury.