Role of the neutrophil in the development of systemic inflammatory response syndrome and sepsis following abdominal aortic surgery

Total hip and knee replacement surgery results in changes in leukocyte and endothelial markers

BACKGROUND

It is estimated that over 8 million people in the United Kingdom suffer from osteoarthritis. These patients may require orthopaedic surgical intervention to help alleviate their clinical condition. Investigations presented here was to test the hypothesis that total hip replacement (THR) and total knee replacement (TKR) orthopaedic surgery result in changes to leukocyte and endothelial markers thus increasing inflammatory reactions postoperatively.

METHODS

During this 'pilot study', ten test subjects were all scheduled for THR or TKR elective surgery due to osteoarthritis. Leukocyte concentrations were measured using an automated full blood count analyser. Leukocyte CD11b (Mac-1) and CD62L cell surface expression, intracellular production of H(2)O(2 )and elastase were measured as markers of leukocyte function. Von Willebrand factor (vWF) and soluble intercellular adhesion molecule-1 (sICAM-1) were measured as markers of endothelial activation.

RESULTS

The results obtained during this study demonstrate that THR and TKR orthopaedic surgery result in similar changes of leukocyte and endothelial markers, suggestive of increased inflammatory reactions postoperatively. Specifically, THR and TKR surgery resulted in a leukocytosis, this being demonstrated by an increase in the total leukocyte concentration following surgery. Evidence of leukocyte activation was demonstrated by a decrease in CD62L expression and an increase in CD11b expression by neutrophils and monocytes respectively. An increase in the intracellular H(2)O(2 )production by neutrophils and monocytes and in the leukocyte elastase concentrations was also evident of leukocyte activation following orthopaedic surgery. With respect to endothelial activation, increases in vWF and sICAM-1 concentrations were demonstrated following surgery.

CONCLUSION

In general it appeared that most of the leukocyte and endothelial markers measured during these studies peaked between days 1-3 postoperatively. It is proposed that by allowing orthopaedic surgeons access to alternative laboratory markers such as CD11b, H(2)O(2 )and elastase, CD62L, vWF and sICAM-1, an accurate assessment of the extent of inflammation due to surgery per se could be made. Ultimately, the leukocyte and endothelial markers assessed during this investigation may have a role in monitoring potential infectious complications that can occur during the postoperative period.

Circulating CD10-/CD16low neutrophils provide a quantitative index of active bone marrow neutrophil release

Circulating neutrophil phenotype and function are altered during neutrophilia associated with acute inflammatory states, however, the contribution of bone marrow neutrophil release to these changes has been difficult to quantify in humans. Accelerated release of neutrophils, with potentially distinct attributes, from the bone marrow and their dilution within the circulating pool may produce these apparent changes. Unfortunately selective analysis of these newly emergent neutrophils is difficult given their morphologic similarity to those already in the circulation and the coincident effect of soluble inflammatory mediators on circulating neutrophil phenotype and function. Using whole blood flow cytometry and cardiac surgery as an inflammatory stimulus, we demonstrate the emergence of a unique subpopulation of circulating neutrophils characterised as CD10(-)/CD16(low), indicative of active bone marrow neutrophil release peri-operatively. CD10(-)/CD16(low) neutrophils emerge at the same operative stages as band forms and a left shift, yet represent over 40% of circulating neutrophils postoperatively, and generate a greater stimulus-induced [Ca(2+)](i) flux than their CD10(+) counterparts. We conclude that CD10(-)/CD16(low) neutrophils represent a significant proportion of the circulating pool after cardiac surgery and that bone marrow release, a major contributor to neutrophilia, influences the phenotype and functional activity of circulating neutrophils following this acute inflammatory stimulus.

Effects of ovariohysterectomy on canine blood neutrophil respiratory burst: a chemiluminescence study

OBJECTIVE

To examine blood neutrophil counts and luminol-enhanced chemiluminescence (CL) responses in dogs undergoing ovariohysterectomy (OH), premedicated with 2 different drugs.

STUDY DESIGN

Randomized clinical study.

ANIMALS

Forty-two healthy client-owned bitches.

METHODS

Dogs had OH under isoflurane anesthesia with either acepromazine or medetomidine, both in combination with butorphanol, administered as preanesthetic medication. Blood samples were collected when the dog was admitted, at the end of surgery, and the next day (approximately 20 hours after surgery). Blood neutrophils were counted automatically, and neutrophil oxidative activity was assessed by measuring blood CL responses (induced by opsonized zymosan and enhanced by luminol) at 37 degrees C for 40 minutes.

RESULTS

Number of circulating neutrophils was significantly increased the day after surgery reflected by enhanced blood CL responses. Neutrophil CL, however, was not significantly altered. No significant differences were detected for perioperative Polymorphonuclear neutrophil (PMN) characteristics between the 2 preanesthetic regimens.

CONCLUSIONS

In conclusion, despite clearly increasing the number of circulating neutrophils, OH did not significantly affect neutrophil respiratory burst, as measured by whole-blood CL responses.

CLINICAL RELEVANCE

Surgical operation of moderate intensity (e.g., OH) did not significantly alter one of the important immune functions, neutrophil oxidative activity. Further studies are warranted to confirm the significance of this finding, and to assess the value of following this variable in different animal patient populations.

Modulation of human leukocyte antigen-DR on monocytes and CD16 on granulocytes in patients with septic shock using hemoperfusion with polymyxin B-immobilized fiber

BACKGROUND

Hemoperfusion with PMX-F (polymyxin B covalently immobilized on fibers) has been reported to be safe and effective for patients with septic shock. However, the molecular mechanism of this usefulness is not yet clear. The purpose of this study was to evaluate whether the expression of CD14, human leukocyte antigen (HLA)-DR on monocytes, and the expression of CD16, CD11b/CD18 on neutrophils, are altered in septic patients according to the severity, and whether PMX-F treatment affects the clinical parameters and the expression of leukocyte surface antigen expression.

PATIENTS AND METHODS

Thirty-four patients who were taken to the National Defense Medical College hospital at emergency, and who had an identified focus of infections, were enrolled in this study. The patients were divided into three groups: non-systemic inflammatory response syndrome [SIRS]) group, sepsis group, and septic shock group. Peripheral blood samples were collected at the time of admission to our hospital. The CD14, HLA-DR expression on monocytes and the CD11b/CD18, CD16 expression on granulocytes were evaluated using flowcytometry, and the serum interleukin (IL)-6 and IL-10 levels were measured using enzyme-linked immunosorbent assay. Treatment with a PMX-F column was performed in 10 patients with septic shock.

RESULTS

The HLA-DR expression on monocytes and the CD16 intensity on granulocytes in patients with septic shock were significantly lower than those in patients with sepsis. The serum IL-6 and 10 levels in patients with septic shock were significantly higher than those in patients with sepsis. The mean systolic blood pressure in patients with septic shock was significantly increased after the PMX-F treatment; furthermore, the HLA-DR expression on monocytes and the CD16 intensity on granulocytes were significantly increased after the PMX-F treatment. The serum IL-10 levels were significantly decreased after the PMX-F treatment.

CONCLUSIONS

We showed that the surface antigens, HLA-DR on monocytes and CD16 on granulocytes, are extremely decreased in patients with septic shock, and that PMX-F treatment is effective for beneficially increasing the surface antigen expression on leukocytes. This therapy might be a new strategy for helping patients recover from immunoparalysis in septic conditions.

Effect of inhaled endotoxin on airway and circulating inflammatory cell phagocytosis and CD11b expression in atopic asthmatic subjects

BACKGROUND

In a cohort of 8 normal and 10 allergic asthmatic volunteers, we previously reported that inhalation of 5 microg of endotoxin (LPS) induced airway inflammation that correlated with CD14 expression that was, in turn, correlated with eosinophil numbers in the airway. Macrophage and neutrophil functions have been reported to be modified by endotoxin in vitro and in vivo, and response to endotoxin is mediated largely by airway phagocytes and related to allergic inflammation.

OBJECTIVE

We sought to examine functional and cell-surface phenotype changes in phagocytes recovered from atopic asthmatic subjects after endotoxin challenge.

METHODS

Sputum and peripheral blood from 10 allergic asthmatic subjects was recovered after saline and LPS challenge. Assessment of phagocytosis and cell-surface phenotype (CD11b, CD14, and CD64) was performed on phagocytes obtained from sputum (n = 7) and blood samples (n = 10).

RESULTS

Phagocytosis of blood and sputum phagocytes was blunted after LPS challenge in a fashion that correlated with the increase in airway neutrophils after LPS challenge. Cell-surface expression of CD14 (membrane-bound CD14) was increased in sputum cells, whereas CD11b was decreased in sputum and circulating phagocytes. Baseline expression of CD11b in blood correlated with the magnitude of the neutrophil response after LPS inhalation, as well as (inversely) with baseline airway eosinophil levels.

CONCLUSIONS

Inhalation of endotoxin at levels adequate to induce a neutrophil influx to the airways (but not systemic symptoms) results in decreased phagocytosis in both airway and circulating cells and modifies CD11b expression in a way that implicates its involvement in phagocyte responsiveness to inhaled LPS.