Cytokine and fibrinogen response in patients undergoing open abdominal aortic aneurysm surgery

Potential of Disease-Modifying Anti-Rheumatic Drugs to Limit Abdominal Aortic Aneurysm Growth

Inflammation is strongly implicated in the pathogenesis of abdominal aortic aneurysms (AAA). This review examined the potential role of biologic disease-modifying anti-rheumatic drugs (bDMARDs) as repurposed drugs for treating AAA. Published evidence from clinical and preclinical studies was examined. Findings from animal models suggested that a deficiency or inhibition of tumour necrosis factor-α (TNF-α) (standard mean difference (SMD): −8.37, 95% confidence interval (CI): −9.92, −6.82), interleukin (IL)-6 (SMD: −1.44, 95% CI: −2.85, −0.04) and IL-17 (SMD: −3.36, 95% CI: −4.21, −2.50) led to a significantly smaller AAA diameter compared to controls. Human AAA tissue samples had significantly increased TNF-α (SMD: 1.68, 95% CI: 0.87, 2.49), IL-1β (SMD: 1.93, 95% CI: 1.08, 2.79), IL-6 (SMD: 2.56, 95% CI: 1.79, 3.33) and IL-17 (SMD: 6.28, 95% CI: 3.57, 8.99) levels compared to non-AAA controls. In human serum, TNF-α (SMD: 1.11, 95% CI: 0.25, 1.97) and IL-6 (SMD: 1.42, 95% CI: 0.91, 1.92) levels were significantly elevated compared to non-AAA controls. These findings implicate TNF-α, IL-17 and IL-6 in AAA pathogenesis. Randomised controlled trials testing the value of bDMARDs in limiting AAA growth may be warranted.

EVAR and OPEN treatment of abdominal aortic aneurysm: What is the role of MMP-9 in the follow-up?

INTRODUCTION

The aim of our study is to verify the role of metalloproteinases in endovascular repair (EVAR) and OPEN surgery treatment for abdominal aortic aneurysm (AAA). Postoperatively, these enzymes could represent an important biomarker to adapt diagnostic tests and further investigations during follow-up.

MATERIAL AND METHOD

From 2004 to 2008, 55 patients were considered with AAA. Of these, 33 patients (mean age: 70.1 years), (mean AAA diameter: 5.4cm) were treated with OPEN surgery (group A) and 22 (mean age: 74.1 years) (mean AAA diameter: 5.1cm) were treated with EVAR. In 17 of them, there were no signs of endoleak (group B1), while in 5 patients, a presence of endoleak (group B2) was detected. Plasma samples were collected in order to determine MMP-9 activity. Enzyme immunoassay was performed preoperatively at 1, 3, 6 and 12 months. Patients treated conventionally were clinically examined after 1 and 12 months by ultrasound. Patients undergoing EVAR treatment were clinically examined by CT scan after 1, 3, 6 and 12 months. The analysis was done by assessing the interaction over time of the MMP-9 value in B1 and B2 groups.

RESULTS

The average values observed for MMP-9 were preoperatively and at 1, 3, 6 and 12 months, respectively: in group A 150.8ng/mL (SD=30.5), 252.5ng/mL (SD=25.2), 315.4ng/mL (SD=22.7), 295.3ng/mL (SD=26.8), 210.7ng/mL (SD=30.2); in group B1 105ng/mL (SD=10.8), 125.6ng/mL (SD=18), 85.8ng/mL (SD=19.9), 95ng/mL (SD=20.2), 80.4ng/mL (SD=15.6); in group B2 149ng/mL (29.2), 375.4ng/mL (SD=40.2), 215ng/mL (SD=35.9), 180ng/mL (SD=20.2), 175ng/mL (SD=33.4). The MMP-9 level was higher in group B2 compared to group B1 (P=0.01), suggesting a correlation with the presence of the endoleak.

CONCLUSIONS

This preliminary study shows that MMP-9 may be a biomarker of the presence of endoleak. Other further investigations and larger series are needed to show that metalloproteases could play a role in the follow-up of EVAR treated patients.

Effect of Mesenteric Ischemia/Reperfusion on Spinal Cord Injury following Transient Aortic Occlusion in Rabbits

Purpose:

To investigate in a rabbit model if prolonged periods of mesenteric ischemia followed by reperfusion may affect the rate of neurological complications.

Methods:

An infrarenal aortic snare, which consisted of a Silastic vessel loop whose ends were passed through plastic tubing, was placed in 50 male New Zealand white rabbits. In 40 of these animals, a similar but smaller device was placed around the superior mesenteric artery (SMA); all devices were exteriorized to allow vessel occlusion in the awake animal. The aorta was occluded for 12 minutes in the 10 control and 40 experimental animals, but the experimental rabbits also had occlusion of the SMA for varying intervals: 10 minutes (group 1), 12 minutes (group 2), and 18 minutes (group 3). To assess the hemodynamic effects of aortic and aortic/SMA occlusion, select control and test animals had blood pressure and heart rate monitoring via indwelling carotid catheters during the occlusion periods. The animals were euthanized, and spinal cords from paralyzed and normal rabbits were examined histologically

Results:

Neurological deficit occurred in 20% of controls and in 70%, 80%, and 100% in the experimental groups, respectively. There were no significant differences in systemic blood pressure at any time point during occlusion and reperfusion in the monitored control or test animals. There was no evidence of thrombosis of spinal arteries on histological analysis, nor was there evidence of bowel infarction at the time of sacrifice in animals undergoing combined aortic/SMA occlusion.

Conclusions:

Mesenteric ischemia/reperfusion worsens the neurological outcome in animals undergoing transient aortic occlusion. This observation is independent of hemodynamic influences and not the result of spinal artery thrombosis.

Interplay between Coagulation and Inflammation in Open and Endovascular Abdominal Aortic Aneurysm Repair — Impact of Intra-Aneurysmal Thrombus

Aims:

Our aim was to compare hemostatic and inflammatory mechanisms in abdominal aortic aneurysm (AAA) patients after open surgery (OPEN) and endovascular AAA repair (ENDO).

Subjects and Methods:

From the 32 consecutive AAA patients recruited, 17 represented ENDO and 15 OPEN. The intra-aneurysmal thrombus was removed during OPEN, but stayed intact after ENDO. The pre-operative volume of the intra-aneurysmal thrombus was calculated from computed tomography images. Markers of coagulation and inflammation were studied pre-operatively, at one, two, three, four and seven days and at three months postoperatively.

Results:

Preoperative upregulation of F 1 + 2, TAT and D-dimer was evident in both groups. The volume of intra-aneurysmal thrombus correlated with CRP (β=0.62, p=0.001), IL-6 (β=0.60, p=0.001) and PAI-1 ag (β=0.51, p=0.007). Surgery further enhanced inflammation, coagulation and fibrinolysis. IL-6 increased in both groups, but the increases of CRP and PIIINP were higher in the OPEN group. Postoperative CRP correlated with the intra-aneurysmal thrombus volume in the ENDO group. At three months D-dimer (p<0.05) was higher than pre-operatively in the ENDO, in contrast to the OPEN group.

Conclusion:

Preoperatively both prothrombotic and fibrinolytic mechanisms are activated in patients with AAA. Intraluminal thrombus induces prothrombotic and inflammatory interactions, which persist after endovascular aortic aneurysm repair.

The Effect of Perioperative Ischemia and Reperfusion on Multiorgan Dysfunction following Abdominal Aortic Aneurysm Repair

Abdominal aortic aneurysms (AAAs) are relatively common and are potentially life-threatening medical problems. The aim of this review is to provide an overview of the effect of I/R injury on multiorgan failure following AAA repair. The PubMed, CINAHL, EMBASE, Medline, Cochrane Review, and Scopus databases were comprehensively searched for articles concerning the pathophysiology of I/R and its systemic effects. Cross-referencing was performed using the bibliographies from the articles obtained. Articles retrieved were restricted to those published in English. One of the most prominent characteristics of AAA open repair is the double physiological phenomenon of ischemia-reperfusion (I/R) that happens either at the time of clamping or following the aortic clamp removal. Ischemia-reperfusion injury causes significant pathophysiological disturbances to distant organs, increasing the possibility for postoperative multiorgan failure. Although tissue injury is mediated by diverse mechanisms, microvascular dysfunction seems to be the final outcome of I/R.

Inflammatory mediators in intra-abdominal sepsis or injury - a scoping review

Introduction

Inflammatory and protein mediators (cytokine, chemokine, acute phase proteins) play an important, but still not completely understood, role in the morbidity and mortality of intra-abdominal sepsis/injury. We therefore systematically reviewed preclinical and clinical studies of mediators in intra-abdominal sepsis/injury in order to evaluate their ability to: (1) function as diagnostic/prognostic biomarkers; (2) serve as therapeutic targets; and (3) illuminate the pathogenesis mechanisms of sepsis or injury-related organ dysfunction.

Methods

We searched MEDLINE, PubMed, EMBASE and the Cochrane Library. Two investigators independently reviewed all identified abstracts and selected articles for full-text review. We included original studies assessing mediators in intra-abdominal sepsis/injury.

Results

Among 2437 citations, we selected 182 studies in the scoping review, including 79 preclinical and 103 clinical studies. Serum procalcitonin and C-reactive protein appear to be useful to rule out infection or monitor therapy; however, the diagnostic and prognostic value of mediators for complications/outcomes of sepsis or injury remains to be established. Peritoneal mediator levels are substantially higher than systemic levels after intra-abdominal infection/trauma. Common limitations of current studies included small sample sizes and lack of uniformity in study design and outcome measures. To date, targeted therapies against mediators remain experimental.

Conclusions

Whereas preclinical data suggests mediators play a critical role in intra-abdominal sepsis or injury, there is no consensus on the clinical use of mediators in diagnosing or managing intra-abdominal sepsis or injury. Measurement of peritoneal mediators should be further investigated as a more sensitive determinant of intra-abdominal inflammatory response. High-quality clinical trials are needed to better understand the role of inflammatory mediators.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1093-4) contains supplementary material, which is available to authorized users.

Circulating interleukin-6 levels are associated with abdominal aortic aneurysm presence: a meta-analysis and meta-regression of case-control studies

BACKGROUND

In a number of relatively small-size studies, investigators have measured and compared circulating interleukin-6 (IL-6) levels in cases with abdominal aortic aneurysm (AAA) and controls without AAA to assess its possible role in the pathogenesis or progression of AAA. To summarize the present evidence for an association between circulating IL-6 levels and AAA presence, we performed a meta-analysis of case-control studies that compared circulating IL-6 levels between patients with AAA and subjects without AAA.

METHODS

MEDLINE and EMBASE were searched through December 2013 using Web-based search engines (PubMed and OVID). Eligible studies were case-control studies of patients with AAA and subjects without AAA reporting circulating IL-6 levels. For each study, data regarding plasma or serum IL-6 levels in both the AAA and control groups were used to generate standardized mean differences (SMDs) and 95% confidence intervals (CIs). Mixed-effects (unrestricted maximum likelihood) meta-regression analyses were performed to determine whether the differences in circulating IL-6 levels were modulated by the prespecified factors.

RESULTS

Our search identified 13 eligible studies enrolling a total of 1,029 cases with AAA and 924 controls without AAA. Pooled analysis of the 13 studies demonstrated significantly greater circulating IL-6 levels in the AAA group than those in the control group (random-effects SMD 0.59; 95% CI 0.37-0.80; P for effect < 0.00001; P for heterogeneity < 0.0000). The meta-regression coefficient for the mean age (P = 0.10196) and the proportion of current smokers (P = 0.29893) was not statistically significant. That for the mean AAA diameter, however, was significantly positive (coefficient 0.02789; 95% CI 0.00778-0.04800; P = 0.00657), and that for the proportion of men was significantly negative (coefficient -0.01823; 95% CI -0.03202 to -0.00445; P = 0.00952).

CONCLUSIONS

Circulating IL-6 levels are greater in patients with AAA than those in subjects without AAA, which suggest that greater circulating IL-6 levels are associated with AAA presence. As the mean AAA diameter and the proportion of men increase, circulating IL-6 levels in patients with AAA are respectively more and less greater than those in controls without AAA.

Effect of perioperative immuno-enhanced enteral nutrition on inflammatory response, nutritional status, and outcomes in head and neck cancer patients undergoing major surgery

Administration of immuno-enhanced nutritional support may decrease postoperative morbidity, mortality, and infectious complications in cancer patients. The aim of this study was to verify that perioperative enteral diet, enriched with the nutrients arginine, ribonucleic acid (RNA), and ω-3 fatty acids improves outcomes of head and neck cancer patients undergoing major surgery. Forty patients with squamous cell carcinoma of the head and neck were studied. Group 1 received no preoperative nutritional support, whereas Group 2 received an oral formula with nutrients arginine, RNA, and ω-3 fatty acids. After surgery, Group 1 received a standard enteral formula, whereas Group 2 received an enriched enteral formula. Albumin (g/dl), prealbumin, fibrinogen, CRP, Il-6, and TNFa were measured 5 days before and 8 days after surgery. No statistically significant difference was observed for all the evaluated markers between postoperative and preoperative levels for both groups. The rate of complications was significantly reduced in the total number of patients receiving immunonutrition and in the particular subgroup of well-nourished patients receiving an immuno-enhanced diet. Perioperative enteral immuno-enhanced feeding in head and neck cancer patients undergoing major surgery may influence the postoperative outcomes by reducing the frequency rate of infections and wound complications.

Early Inflammatory Response in Patients With Ruptured Abdominal Aortic Aneurysm

Multiorgan failure is the main cause of death in patients operated for ruptured abdominal aortic aneurysm (rAAA). The systemic inflammatory response plays a central role in the generation and maintenance of multiorgan dysfunction. The aim of the current study was to investigate the inflammatory response preoperatively in patients with ruptured and nonruptured AAA in relation to the clinical outcome. A total of 95 patients about to undergo repair of AAA (43 ruptured with shock, 12 ruptured without shock, and 40 elective) and 41 controls without aneurysm matched by age, gender, and smoking habits were investigated by inflammatory markers. There were significantly higher levels of interleukin 6 (IL-6; proinflammatory cytokine) and IL-10 (anti-inflammatory cytokine) in patients operated for ruptured compared to nonruptured AAA. In conclusion, the current data indicate that rupture of an AAA activates the inflammatory system with a compensatory anti-inflammatory response.

Proinflammatory and Anti-inflammatory Cytokine Balance in Patients With Abdominal Aortic Aneurysm and the Impact of Aneurysm Size

Abdominal aortic aneurysm is a common condition with high mortality due to rupture; however, the condition also is associated with nonaneurysmal cardiovascular mortality. A possible contributing mechanism for the cardiovascular mortality is an imbalance between the proinflammatory and anti-inflammatory systemic response. In the present study, 78 patients with abdominal aortic aneurysm and 41 controls without aneurysm matched by age, gender and smoking habits were investigated. Cytokines such as interleukin-6, interleukin-10, and monocyte chemoattractant protein-1 were measured in plasma. There was significantly higher level of interleukin-6 in patients with AAA compared to controls. The interleukin-6/ interleukin-10 ratio was highest in patients with large compared to small abdominal aortic aneurysm. In conclusion, the present data indicate a proinflammatory response and a proinflammatory to antiinflammatory imbalance in patients with abdominal aortic aneurysm which is dependent by aneurysm size.

The intestinal tract as the major source of interleukin 6 production during abdominal aortic clamping and hind limb ischaemia-reperfusion injury

PURPOSE

The aim of this study was to investigate whether the hind limbs or intestinal tract is the most important initiator of the inflammatory response secondary aortic clamping and hind limb ischemia/reperfusion injury.

METHODS

Blood samples of Wistar rats obtained from posterior cava vein, portal vein, and heart cavity during either laparotomy (control group, n=8) or laparotomy + 2 h of aortic clamping and bilateral hind limb ischemia (ischemia group, n=8), or 2 h after ischemia and 2 h of reperfusion (ischemia-reperfusion group, n=8) were assayed for interleukin 6 (IL-6) and C-reactive protein (CRP).

RESULTS

Serum IL-6 at the heart (223.6+/-197.9 [10-832] pg/mL) was higher (p<0.001) than at both portal (133.08+/-108.52 [4-372] pg/mL) and posterior cava veins (127.58+/-109.15 [8-388] pg/mL). CRP was not significant different among groups.

CONCLUSION

The splanchnic region is also a source of inflammatory response secondary to ischemia and reperfusion of the hind limbs.

The effect of Nomega-nitro-L-arginine methyl ester and L-arginine on lung injury induced by abdominal aortic occlusion-reperfusion

PURPOSE

The aim of this study was to examine the effects of Nomega-nitro-L-arginine methyl ester (L-NAME) and L-arginine on lung injury after aortic ischemia-reperfusion (IR).

METHODS

Twenty-four Wistar-Albino rats were randomized into four groups (n = 6) as follows: Control (sham laparotomy), Aortic IR (30 min ischemia and 120 min reperfusion), L-Arginine (intraperitoneal 100 mg kg(-1) live weight)+aortic IR, and L: -NAME (intraperitoneal 10 mg kg(-1) live weight)+aortic IR. In the lung specimens, the tissue levels of malondialdehyde (MDA), vascular endothelial growth factor (VEGF), and nitric oxide (NO) were measured and a histological examination was done.

RESULTS

Aortic IR increased MDA, VEGF, and NO. L-Arginine further significantly increased MDA and NO, and decreased VEGF (P < 0.05 vs aortic IR). L-NAME significantly decreased MDA and NO (P < 0.05 vs L-arginine+aortic IR) and increased VEGF (P < 0.05 vs other groups). A histological examination showed the aortic IR to significantly increase (P < 0.05 vs control) while L-arginine also further increased (P > 0.05 vs aortic IR), whereas L-NAME caused a significant decrease in pulmonary leukocyte infiltration (P < 0.05 vs aortic IR).

CONCLUSIONS

Our results indicate that L-arginine aggravates the lung injury induced by aortic IR, while L-NAME attenuates it.

Postoperative evolution of inflammatory response in a model of suprarenal aortic cross-clamping with and without hemorrhagic shock. Systemic and local reactions

Surgery of the abdominal aorta generates a systemic inflammatory response (SIR), a source of operative morbidity-mortality. In the present work we attempted to evaluate the evolution of SIR in an experimental model that simulates elective and urgent surgery on the abdominal aorta. Fifteen mini-pigs divided into three groups were used. The animals were subjected to suprarenal aortic/iliac clamping and bypass with a Dacron-collagen prosthetic graft. Groups were as follows: (1) sham (only aortic dissection); (2) clamping and bypass; (3) hemorrhage of 40%, pre-clamping, and bypass. Determinations included (1) tumor necrosis factor-alpha (TNF-alpha) interleukin (IL)-1beta, IL-6, IL-10, interferon-gamma; (2) myeloperoxidase (MPO), superoxide anion (SOA), superoxide dismutase (SOD), and malondialdehyde (MDA); (3) nitrites; (4) iNOS, (5) cell adhesion molecules (ICAM-1, VCAM-1) at 24 hours, 48 hours, and on day 7; and (6) NFkappaB at 48 hours. Our results point to an increase in all inflammatory variables, corroborated by their molecular regulators such as the expression of CAMs, iNOS, and NFkappaB. The alterations tended to normalize by day 7, after reperfusion. The results point to the great importance of SIR at all levels (molecular, nuclear, cellular, and systemic) in situations such as elective and urgent abdominal aorta surgery and the role that control of this response could represent for the future of vascular surgery.

Exogenous nitric oxide modulates the systemic inflammatory response and improves kidney function after risk-situation abdominal aortic surgery

OBJECTIVE

Renal impairment is a very frequent complication of aortic surgery requiring prolonged suprarenal clamping, especially if it is associated with previous hemorrhage. The aim of this study was to assess the beneficial effect of the administration of a nitric oxide (NO) donor on renal function through a modulation of the systemic inflammatory response in a model of abdominal aortic surgery.

METHODS

Twenty-five minipigs were divided into five groups. Under anesthesia, the animals were subjected to suprarenal aortic-iliac clamping (for 30 minutes) and bypass with a Dacron-collagen prosthetic graft impregnated in rifampicin, with or without associated hemorrhage (40% of total blood volume). Prophylaxis with cefazolin was implemented. The five groups were (1) the sham group (only aortic dissection), (2) the clamping and bypass (C) group, (3) hemorrhage preclamping and bypass (H+C) group, (4) the same as group C but with the administration of the NO donor molsidomine (4 mg/kg intravenously) (C+NO group), (5) the same as the H+C group but with the administration of the NO donor molsidomine (4 mg/kg intravenously) (H+C+NO group). The following were determined: (1) kidney function (serum creatinine), (2) serum cytokines (tumor necrosis factor alpha [TNF-alpha] and interleukin-10 [IL-10]); (3) neutrophil infiltration (myeloperoxidase [MPO]) in the kidney, (4) oxygen free radicals (superoxide anion [SOA] and superoxide dismutase [SOD]) in the kidney, (5) serum nitrites, (6) soluble and kidney tissue cell adhesion molecule (soluble intercellular adhesion molecule-1 [sICAM-1], soluble vascular cell adhesion molecule-1 [sVCAM-1], intercellular adhesion molecule-1 [ICAM-1], and vascular cell adhesion molecule-1 [VCAM-1]), (7) inducible nitric oxide synthase (iNOS) in the kidney, and (8) nuclear factor-kappaB (NF-kappaB) in the kidney. Determinations were made during ischemia at 15 minutes post-reperfusion; at 24, 48, and 72 hours; and on day 7.

RESULTS

The different insults used in the experimental model led to deterioration in kidney function and an increase in the systemic (and renal) inflammatory response at all levels investigated. Treatment with an NO donor, both with and without associated hemorrhage, reduced the inflammatory response at the systemic (TNF-alpha and IL-10) and kidney (MPO, SOA, and SOD) levels, normalizing kidney function. Likewise, exogenous administration of NO improved the excessive production of NO (nitrites) via iNOS. This was also reflected in a reduction in CAMs and of NF-kappaB expression. The hypotension induced by molsidomine was transitory and did not elicit hemodynamic repercussions.

CONCLUSION

In our experimental model, prophylactic treatment with the NO donor molsidomine regulates the systemic inflammatory response and minimizes damage at the kidney level. Clinical Relevance The importance of this article resides in the fact that an experimental study that clarifies the effect of the donors of NO under circumstances as similar as possible to those of the human clinic, such as aortic surgery under hypovolemic shock (ruptured aortic aneurysm) have been little studied, most of these studies being performed in rodents without bypass. Using a model with one or two simultaneous insults (aortic clamping with/without previous hemorrhage) that is very similar to the human clinical situation (abdominal aortic rupture), we confirm the findings of previous work related to the beneficial effects of NO donors.

The Effect of Acute Normovolaemic Haemodilution on the Inflammatory Response and Clinical Outcome in Abdominal Aortic Aneurysm Repair—Results of a Pilot Trial

OBJECTIVES

To determine the effect of acute normovolaemic haemodilution (ANH) on the inflammatory response and clinical outcome in elective open abdominal aortic aneurysm (AAA) repair.

DESIGN

Randomised controlled clinical trial.

METHODS

Thirty-six patients were randomised to undergo ANH or act as controls. Cell salvage was permitted in both groups. Heterologous blood was transfused according to pre-determined triggers. Outcome measures were markers of the systemic inflammatory response in serum and urine observed at multiple time points, and clinical recovery.

RESULTS

Median 890 (range 670-1620) ml of blood was removed at ANH in 16 patients. There were no differences in peri-operative changes in neutrophil count ( P = 0.13), serum C-reactive protein ( P = 0.38), interleukin-6 ( P = 0.50), total antioxidant capacity ( P = 0.73), urinary secretion of albumin ( P = 0.97) or retinol binding protein ( P = 0.41). There were no differences in the mortality and morbidity rates, systemic inflammatory response syndrome, ITU or hospital stay.

CONCLUSIONS

ANH, when used in combination with cell salvage, made no impact on systemic inflammatory response and clinical outcome when compared to cell salvage alone after AAA repair. ANH cannot be recommended for routine use in patients undergoing abdominal aortic aneurysm surgery when cell salvage is available.

Quantitative detection of changes in cytokine gene expression in peripheral blood mononuclear cells correlates with and precedes acute rejection in renal transplant recipients

Immunological monitoring of transplant recipients is an attractive concept. Cytokines provide an obvious focus for research, as they are central to the human immune response. This study aimed to identify cytokines whose sequential gene expression differentiated rejectors from non-rejectors immediately following renal transplantation. Forty-five renal transplant recipients (15 rejectors) and 13 living donors were recruited. Total RNA was extracted from the peripheral blood mononuclear cells and reverse transcribed. Cytokine gene expression levels of IL-4, IL-10, TNF-alpha and TGF-beta1 were measured using TaqMan. IL-10 expression increased significantly following donor surgery. IL-4 and TNF-alpha patterns clearly differentiated between rejectors and non-rejectors. In the rejectors significant increases occurred more than 48 h before clinical graft dysfunction. Negative predictive values were 76% and 80% for IL-4 and TNF-alpha, respectively. This study has identified two cytokines (IL-4 and TNF-alpha) whose gene expression patterns differentiate between rejecting and non-rejecting renal transplant recipients making immunological monitoring possible.

Aortic Aneurysm Repair Is Associated with a Lower Inflammatory Response Compared with Surgery for Inflammatory Bowel Disease

BACKGROUND

Since the plasma cytokine profile reflects the body's inflammatory response to injury, this study was designed to prospectively observe the plasma cytokine levels in response to the degree of different sorts of abdominal surgical trauma.

METHODS

Plasma levels of TNF-alpha, type I TNF receptor (p55), type II TNF receptor (p75), IL-6, IL-8, IL-10, phospholipase A(2) (PLA(2)), and haptoglobin were measured peri-operatively in patients undergoing bowel resection for inflammatory bowel disease or diverticulitis (IBD) (n = 9), elective repair of abdominal aortic aneurysm (AAA) (n = 9), or laparoscopic cholecystectomy (lap chole) (n = 9).

RESULTS

The IBD patients showed a significant (p < 0.05) post-operative elevation in plasma IL-6, p55, p75, and PLA(2) levels, but no significant change in TNF-alpha, IL-8, IL-10 or haptoglobin levels. The AAA patients had a significant post-operative rise in IL-10 levels and a significant decrease in plasma haptoglobin levels, but no significant change of TNF-alpha, IL-6, IL-8, p55, p75, or PLA(2) concentrations. The lap chole patients demonstrated no significant change in any of these parameters.

CONCLUSION

These data show that IL-6, IL-10, p55, and p75 are markers to measure the degree of inflammatory stress associated with abdominal operative procedures and demonstrate the relative lack of a cytokine response to laparoscopic cholecystectomy.

Ischaemia-Reperfusion Injury and Regional Inflammatory Responses in Abdominal Aortic Aneurysm Repair

OBJECTIVES

The inflammatory response to abdominal aortic aneurysm repair is likely to result in response to an ischaemia-reperfusion injury (IRI) to the lower-limbs and gastrointestinal tract. This paper reviews the pathogenesis of the inflammatory response to abdominal aortic aneurysm repair, with specific reference to the levels of evidence in the current literature regarding the potential origin of the inflammatory response.

DESIGN

Review article.

METHODS

The current literature (1966 to August 2003) was reviewed specifically for all articles employing techniques of regional blood sampling from the venous drainage of the lower limbs or gastrointestinal tract during abdominal aortic aneurysm repair.

RESULTS

Ten relevant studies were identified. These demonstrated that regional blood sampling techniques could be easily performed, and provided useful information regarding the potential sites of origin of the inflammatory response.

CONCLUSIONS

Regional blood sampling techniques provide useful information regarding the potential sites of origin of the inflammatory response. Current evidence suggests that both the lower limbs and gastrointestinal tract are clearly important in their roles, however more work is now required to compare directly the roles and contributions of the lower limbs and gastrointestinal tract to the inflammatory response during abdominal aortic aneurysm repair.

Increased nitrotyrosine production in patients undergoing abdominal aortic aneurysm repair

Background

Vascular inflammation is implicated in the pathogenesis of atherosclerosis and abdominal aortic aneurysm (AAA), and is thought to involve reactive species such as the nitric oxide-derived oxidant peroxynitrite. In the present study nitrotyrosine was measured as a stable marker of peroxynitrite production in vivo.

Methods

Perioperative blood samples were obtained from patients undergoing elective open or endovascular repair of an AAA and from patients with intermittent claudication, smoking aged-matched controls, non-smoking aged-matched controls and non-smoking young healthy controls. Plasma nitrotyrosine was measured by an enzyme-linked immunosorbent assay.

Results

The median plasma nitrotyrosine concentration in patients with an AAA (0·46 nmol nitrated bovine serum albumin equivalents per mg protein) was significantly higher than that in patients with intermittent claudication (0·35 nmol; P = 0·002), smoking controls (0·36 nmol; P = 0·001), non-smoking controls (0·35 nmol; P = 0·002) and young healthy controls (0·27 nmol; P &lt; 0·001). Nitrotyrosine concentrations increased during early reperfusion in open AAA repair, but not during endovascular repair. AAA exclusion from the circulation reduced levels to control values (P = 0·001).

Conclusion

Patients with an AAA had raised levels of circulating nitrated proteins compared with patients with claudication and controls, suggesting a greater degree of ongoing inflammation that was not related to smoking.

Potential prophylactic measures against postoperative immunosuppression: could they reduce recurrence rates in oncological patients?

BACKGROUND

Removing the primary tumor is indispensable for eliminating the major pool of metastasizing cells, but the surgical procedure itself is suspected of promoting metastases. This adverse effect is attributed to several mechanisms acting in synergy, including mechanical release of tumor cells, enhanced angiogenesis, secretion of growth factors, and immunosuppression. Here we provide new insights into mechanisms of postoperative immunosuppression and assess the assumptions underlying the hypothesis that, by suppressing cell-mediated immunity (CMI), surgery may render the patient vulnerable to metastases that otherwise could have been controlled.

METHODS

An extensive review of relevant articles in English identified by using the MEDLINE database and cross-referencing.

RESULTS

Current literature suggests that (1) CMI can control minimal residual disease, especially if surgery is performed early; (2) major surgery transiently but markedly suppresses CMI through multiple mechanisms now better understood; (3) surgical stress promotes experimental metastasis through immunosuppression, but the clinical evidence remains indirect because of ethical limitations.

CONCLUSIONS

Minimizing postoperative immunosuppression seems feasible, may limit recurrence, and should be introduced into the broader array of considerations when planning oncological surgeries. In the short run, physicians could try to avoid immunosuppressive anesthetic approaches, inadvertent hypothermia, excessive blood transfusions, and untended postoperative pain. When feasible, minimally invasive surgery should be considered. In the long run, clinical trials should evaluate prophylactic measures, including perioperative immunostimulation and several antagonists to cytokines and hormones specified herein.

Serum monocyte chemoattractant protein-1 in patients with postoperative infectious complications from gastrointestinal surgery for cancer

We examined the kinetics of serum monocyte chemoattractant protein-1 (MCP-1) perioperatively and clarified its significance regarding the development of infectious complications. We studied 94 patients who underwent gastrointestinal surgery for gastric or colorectal cancer at Mie University Hospital from 1996 to 2000. Serum concentrations of MCP-1 and interleukin-6 (IL-6) were measured perioperatively. The number of circulating lymphocytes and neutrophils were counted to assess the apoptotic rate of neutrophils. Patients were divided into two groups at the median preoperative MCP-1 level obtained from 40 gender- and age-matched healthy volunteers. The rate of developing infectious complications was significantly higher and tumor size was significantly larger in the low MCP-1 group than in the high MCP-1 group. The increasing IL-6 ratio (postoperative/preoperative IL-6 level) in the low MCP-1 group was about twofold greater than that in the high MCP-1 group. The neutrophil level calculated for the low MCP-1 group was significantly higher than that in the high MCP-1 group on postoperative day 3. We concluded that a decreased level of serum MCP-1 reflected tumor-related immunosuppression. Low MCP-1 levels were associated with an exaggerated postoperative IL-6 response and delayed neutrophil apoptosis, which affected the incidence of postoperative infectious complications developing in patients with gastrointestinal malignancies.

Hypertonic resuscitation of hemorrhagic shock upregulates the anti-inflammatory response by alveolar macrophages

BACKGROUND

Resuscitated hemorrhagic shock predisposes patients to the development of acute respiratory distress syndrome (ARDS). Hypertonic saline (HTS) has been shown to inhibit immune cell activation in response to lipopolysaccharide (LPS) in vitro and to reduce lung damage when used for resuscitation of hemorrhagic shock in vivo. We hypothesize that HTS resuscitation of hemorrhagic shock may exert this anti-inflammatory effect by modulating alveolar macrophage function leading to an altered balance between the proinflammatory and the counter-inflammatory response.

METHODS

A 2-hit rat model of shock resuscitation was used. Alveolar macrophages were harvested by bronchoalveolar lavage (BAL), and tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 were quantified in the cell culture supernatants by enzyme-linked immunosorbent assay (ELISA). Alternatively, 1 hour after resuscitation, animals received endotracheal LPS followed by endotracheal anti-IL-10 neutralizing antibody. Lung injury was determined by measuring BAL neutrophil counts 4 hours after LPS in vivo administration.

RESULTS

Systemic administration of HTS significantly modulates the responsiveness of alveolar macrophages. Specifically, HTS resuscitation inhibited LPS-induced TNF-alpha production while enhancing IL-10 release in response to LPS administered ex vivo and in vivo. Anti-IL-10 antibody in vivo partially reversed the lung protective effect of HTS resuscitation.

CONCLUSIONS

HTS resuscitation exerts an immunomodulatory effect on alveolar macrophages by shifting the balance of pro- and counter-inflammatory cytokine production in favor of an anti-inflammatory response. The in vivo data suggest a causal role for HTS-induced augmented IL-10 as protective. These findings suggest a novel mechanism for the in vivo salutary effect of HTS resuscitation on lung injury after resuscitated hemorrhagic shock.

Cytokines and inflammatory pathways in the pathogenesis of multiple organ failure following abdominal aortic aneurysm repair

Multiple organ failure is a common mode of death following abdominal aortic aneurysm repair, particularly after rupture. Cytokines are the principal mediators of the inflammatory response to injury and high levels of circulating cytokines have been associated with poor outcome in major trauma and sepsis. Abdominal aortic aneurysm repair results in an ischaemia-reperfusion injury to the tissues distal to the site of aortic clamping. The inflammatory response in these tissues causes the release of cytokines, principally Interleukins 1-beta, 6, and 8, and Tumour Necrosis Factor alpha. If released in large enough concentrations, these cytokines may enter the circulation and gain access to organs distant to the site of initial injury. Circulating cytokines cause dysfunction of the renal, cardiovascular, respiratory, nervous and musculo-skeletal systems. The combination of these individual changes in organ function is the multiple-organ dysfunction syndrome, which may progress to multiple organ failure.

Pro- and anti-inflammatory cytokine release in open versus endovascular repair of abdominal aortic aneurysm

BACKGROUND

Pro- and anti-inflammatory cytokine release occurs with abdominal aortic aneurysm (AAA) repair although the relative contribution of each is currently poorly understood. Ischaemia-reperfusion injury is thought to play a greater role following open (OR) than endovascular (ER) repair, with resultant greater perioperative morbidity.

METHODS

Thirty-two patients undergoing OR (n = 16) and ER (n = 16) of AAA were studied. Systemic venous (SV) blood was taken at induction (baseline), 0 h (last clamp off), 4, 24, 72 and 144 h, and femoral venous (FV) blood (indwelling catheter; lower torso venous effluent) at 0, 4 and 24 h. The cytokines interleukin (IL) 6, IL-8 and IL-10 were measured in these samples.

RESULTS

In OR, SV and FV IL-6 increased from baseline to a peak at 24 h (SV 589 pg/ml (P = 0.001 versus baseline) and FV 848 pg/ml (P = 0.05)) before declining at 144 h. In ER, there was a similar pattern but the increase was smaller (24 h: SV 260 pg/ml (P = 0.003 versus baseline) and FV 319 pg/ml (P = 0.06)) at all equivalent timepoints compared with OR. IL-8 peaked earlier (4 h) from baseline in both groups before declining by 144 h, and significant differences between SV and FV were seen only in the OR group. IL-10 levels peaked in both groups at 24 h before declining at 144 h, and there were no significant locosystemic differences between the groups.

CONCLUSION

Venous pro-inflammatory cytokine changes (IL-6) are consistent with significantly greater lower-torso reperfusion injury in patients undergoing OR. Smaller responses were seen after ER (IL-6 and IL-8), although both groups showed a similar anti-inflammatory response (IL-10); this pro- and anti-inflammatory imbalance may account for the increased morbidity associated with OR.

Parenteral structured triglyceride emulsion improves nitrogen balance and is cleared faster from the blood in moderately catabolic patients

BACKGROUND

Most postoperative patients lose net protein mass, which reflects loss of muscle tissue and organ function. Perioperative parenteral nutrition may reduce the loss of protein, but in general, with conventional lipid emulsions a waste of protein still remains.

METHODS

We compared the effects on nitrogen balance of an emulsion containing structured triglycerides, a new type of synthesized triglycerides, with an emulsion of a physical mixture of medium- and long-chain triglycerides as part of parenteral feeding in moderately catabolic patients. The first 5 days after placement of an aortic prosthesis patients received total parenteral nutrition (TPN) providing 0.2 g of nitrogen per kg body weight per day; energy requirement was calculated using Harris and Benedict's equation, adding 300 kcal per day for activity. Twelve patients were treated with the structured triglyceride emulsion and 13 patients with the emulsion of the physical mixture of medium- and long-chain triglycerides. The design was a randomized, double-blind parallel study.

RESULTS

In the patients who completed the study, the mean cumulative nitrogen balance over the first 5 postoperative days was -8+/-2 g in 10 patients on the structured triglyceride emulsion and -21+/-4 g in 9 patients on the emulsion of the physical mixture of medium- and long-chain triglycerides; the mean difference was 13 g of nitrogen (95% confidence interval 4 to 22, p = .015) in favor of the structured triglyceride emulsion. On the first postoperative day serum triglyceride and plasma medium-chain free fatty acid levels increased less during infusion of the structured triglyceride emulsion than with the physical mixture emulsion.

CONCLUSIONS

The parenteral structured triglyceride emulsion improves the nitrogen balance and is cleared faster from the blood, compared with the emulsion of the physical mixture of medium- and long-chain triglycerides, in moderately catabolic patients.

Initial inhibition of tissue factor signalling reduces chronic vascular changes in isogenic rat aortic transplants

Vascular changes are considered the major histopathological indicator of chronic allograft dysfunction. These changes are characterized by intimal thickening caused by accumulation of primarily smooth muscle cells. Contributing factors may be of both immunological and nonimmunological origin. Cold ischemia has been shown to trigger intimal proliferation in the absence of alloantigen in an isogenic rat aortic transplant model. We have used this model to investigate the impact of inhibition of tissue factor (TF) signalling on the progression of intimal thickening. Group 1 was treated with recombinant FVIIa inhibited in its active site (rFVIIai), and group 2 served as untreated controls. At 8 weeks the intimal area was measured with image analysis. Medial areas and the proportion of medial necrosis were determined. Animals treated with rFVIIai showed significantly less intimal thickening compared with controls: median 0.147 vs. 0.256 mm2, respectively (p = 0.008). A positive correlation between intimal hyperplasia and medial necrosis (r(s) = 0.79, p = 0.01), as well as adventitial inflammation (r(s) = 0.83, p = 0.009), was found. TF mRNA was not detected in the neointima at 8 weeks, as determined by in situ hybridization. We conclude that active site inhibited FVIIa (rFVIIai) given prior to and directly after implantation of aortic transplants significantly reduces intimal hyperplasia caused by nonimmunological factors in this model.

The Inflammatory Response and its Consequence for the Clinical Outcome Following Aortic Aneurysm Repair

OBJECTIVE

to review published studies on the outcome of the inflammatory response after abdominal aortic aneurysm (AAA) repair.

METHODS

a literature search on PubMed was performed. All studies that determined the inflammatory response (cytokine release) after AAA repair were included. The results of the studies and differences between open and endoluminal repair were compared and evaluated.

RESULTS

seventeen studies were identified. In most studies the investigated cytokines were TNF-alpha and IL-6. Determination of IL-1 beta, IL-8, TNFsr1 and TNFsr2 were less often performed. TNF-alpha may reflect, but not strictly predict, the clinical outcome in patients with ruptured AAA. IL-6 levels correlate well with the surgical trauma per se. Variations in recorded cytokine release during endovascular AAA repair may depend on the times of blood sampling.

CONCLUSION

both open and endovascular AAA repair provoke a cytokine response. This response is greater during open repair than during endovascular aortic aneurysm exclusion.

Interleukin-10 appearance following thoraco-abdominal and abdominal aortic aneurysm repair is associated with the duration of visceral ischaemia

OBJECTIVES

to evaluate the plasma IL-10 levels during elective operative repair of thoraco-abdominal and abdominal aortic aneurysm repair. To study whether IL-10 plasma levels are associated with the duration of cross-clamping (ischaemia) and clinical outcome.

MATERIALS

fifteen consecutive patients undergoing surgery for TAAA and 10 consecutive patients undergoing surgical repair of AAA were included.

METHODS

plasma concentrations of IL-10 were measured by ELISA technique. Clinical outcome of the TAAA patients was prospectively analysed.

RESULTS

during aortic clamping IL-10 was produced in both populations. The plasma IL-10 peak (934+/-172 pg/ml) of the TAAA group was seen at 4 h after declamping and remained detectable after 48 h. The plasma IL-10 peak (212+/-32 pg/ml) of the AAA group was seen 30 min after declamping and fell to undetectable levels by 24 h. These data show that the peak IL-10 plasma levels in TAAA repair are significantly (p<0.05) higher compared to the peak IL-10 plasma levels as seen during AAA repair. A positive correlation was seen between cross-clamping and peak plasma IL-10 and organ dysfunction.

CONCLUSIONS

IL-10 plasma concentrations appear higher, later and are longer detectable in patients undergoing TAAA. Correlations were seen with duration of cross-clamping and MSOD.

Early inflammatory response after elective abdominal aortic aneurysm repair: a comparison between endovascular procedure and conventional surgery

OBJECTIVE

To determine the nature of and to compare the inflammatory responses induced by (1) endovascular and (2) conventional abdominal aortic aneurysm (AAA) repair.

MATERIAL AND METHODS

Twelve consecutive patients undergoing elective infrarenal AAA repair were prospectively studied. Seven patients were selected for endovascular procedures (the EAAA group); five patients underwent open surgery (the OAAA group). Three control patients undergoing carotid thromboendarterectomy were also included. Serial peripheral venous blood samples were collected preoperatively, immediately after declamping or placement of the endograft, and at hours 1, 3, 6, 12, 24, 48, and 72. Acute phase response expression of peripheral T lymphocyte and monocyte activation markers and adhesion molecules (flow cytometry), soluble levels of cell adhesion molecules (enzyme-linked immunosorbent assay), cytokine (tumor necrosis factor alpha, interleukin-6, and interleukin-8) release (enzyme-linked immunosorbent assay), and liberation of complement products (nephelometry) were measured.

RESULTS

Regarding acute phase response, the EAAA and OAAA groups showed significant increases in C-reactive protein (P <.001 and P =.001), body temperature (P =.035 and P =.048), and leukocyte count (P <.001 and P <.001). Similar time course patterns were observed with respect to body temperature (P =.372). Statistically significant different patterns were demonstrated for C-reactive protein (P =.032) and leukocyte count (P =.002). Regarding leukocyte activation, a significant upregulation of peripheral T lymphocyte CD38 expression was observed in the OAAA group only (P =.001). Analysis of markers such as CD69, CD40L, CD25, and CD54 revealed no perioperative fluctuations in any group. Regarding circulating cell adhesion molecules, the EAAA and OAAA groups displayed significant increases in soluble intercellular adhesion molecule-1 (P =.003 and P =.001); there was no intergroup difference (P =.193). All groups demonstrated high soluble von Willebrand factor levels (P =.018, P =. 007, and P =.027), there being no differences in the patterns (P =. 772). Otherwise, soluble vascular cell adhesion molecule-1, soluble E-selectin, and soluble P-selectin did not appear to vary in any group. Regarding cytokine release, although a tendency toward high tumor necrosis factor alpha and interleukin-8 levels was noticed in the EAAA group, global time course effects failed to reach statistical significance (P =.543 and P =.080). In contrast, interleukin-6 showed elevations in all groups (P =.058, P <.001, and P =.004). Time course patterns did not differ between the EAAA and OAAA groups (P =.840). Regarding complement activation, the C3d/C3 ratio disclosed significant postoperative elevations in the EAAA and OAAA groups (P =.013 and P =.009). This complement product release was reduced in the EAAA group (P <.001).

CONCLUSIONS

The current study indicated that both endovascular and coventional AAA repair induced significant inflammatory responses. Our findings showed that there were no large differences between the procedures with respect to circulating cell adhesion molecule and cytokine release. Moreover, the endoluminal approach produced a limited response in terms of acute phase reaction, T lymphocyte activation, and complement product liberation. This might support the concept that endovascular AAA repair represents an attractive alternative to open surgery. Given the relatively small sample size, further larger studies are required for confirmation of our observations.

The inflammatory response following treatment of abdominal aortic aneurysms: a comparison between open surgery and endovascular repair

OBJECTIVES

to compare the inflammatory response following endovascular and conventional AAA repair.

DESIGN

prospective study.

PATIENTS AND METHODS

ten patients were selected for open surgery (OPEN) and ten for endovascular (ENDO) AAA repair. Leukocytes, platelets, myeloperoxidase, lactoferrin, beta-thromboglobulin, C-reactive protein (CRP), interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-alpha) and complement activation products were measured before, during and after surgery.

RESULTS

in the OPEN group the median hospital stay was longer (6 vs. 12 days, p=0.001) and more patients required transfusion (p=0.02). IL-6 and CRP increased postoperatively, most in OPEN (p<0.01). Platelet counts decreased after the first angiography in ENDO (p<0.01) and before aortic cross-clamping in OPEN (p<0.05). The decrease was larger in OPEN (p=0.02). Leukocyte counts decreased after the first angiography in ENDO, and thereafter increased (p=0.001). An equivalent increase was observed in OPEN after declamping (p=0.001). Leukocyte and platelet degranulation products increased after the first angiography in ENDO and after declamping in OPEN. Changes in complement activation products were small. TNF-alpha did not change significantly.

CONCLUSION

endovascular AAA repair caused significant leukocyte and platelet activation. Based on the timing of activation this could be caused by radiographic contrast media.

Modulating effects of the feeding route on stress response and endotoxin translocation in severely stressed patients receiving thoracic esophagectomy

Experimental studies have demonstrated that the route of nutritional supply impacts the systemic metabolic responses after surgical injury. Intestinal mucosal atrophy, as induced by total parenteral nutrition (TPN) or prolonged bowel rest, has been reported to enhance bowel endotoxin translocation. The operative procedure for thoracic esophageal cancer, including thoracotomy, laparotomy, and three-field lymph-node dissection, is a particularly stressful surgery that requires long-term aggressive nutritional support and often results in the postoperative hypermetabolic state, leading to perturbation of postoperative immune function. Interleukin-6 (IL-6) plays an important role in host inflammatory responses, whereas IL-10 is linked to suppression of cellular immunity. The aim of this study was to investigate how the antecedent nutritional routes influence systemic IL-6 and IL-10 responses and endotoxin translocation after an operation for thoracic esophageal cancer. Twenty-nine patients who underwent esophagectomy with three-field lymphadenectomy were investigated. They were assigned to groups receiving either TPN (n = 18) or enteral nutrition (EN; n = 11) providing 35 kcal x kg(-1) x d(-1) of energy and approximately 1.2-1.5 g x kg(-1) x d(-1) of amino acids. These nutritional supports were conducted from 1 wk before the operation to 14 d after the operation. Serum IL-6, IL-10, and endotoxin concentration were measured before and during the operation and at 2 h and 1, 3, and 7 d after the operation. IL-6 in sera was significantly higher after the operation in both groups. In the EN group, however, significantly less IL-6 production was observed on the third and seventh postoperative days when compared with those patients in the TPN group. Similarly, serum IL-10 concentration in the TPN group showed a significantly higher level than that in the EN group. Serum IL-6 showed a significant positive correlation with IL-10 at 2 h and at 7 d after the operation, suggesting that the reduced inflammatory responses were related to the inhibition of the development of postoperative immunosuppression. Endotoxin concentration in sera was significantly lower in the EN group after the operation than in the TPN group. Perioperative EN provides better regulation of inflammatory cytokine responses and may contribute less to immunosuppression after major surgery than parenteral nutrition. The attenuated production of endotoxin induced by EN may play an important role in these phenomena.