Monocyte activation after open and laparoscopic surgery

Multicentric experience with interferon gamma therapy in sepsis induced immunosuppression. A case series

Background

The sepsis-induced immunodepression contributes to impaired clinical outcomes of various stress conditions. This syndrome is well documented and characterized by attenuated function of innate and adaptive immune cells. Several pharmacological interventions aimed to restore the immune response are emerging of which interferon-gamma (IFNγ) is one. It is of paramount relevance to obtain clinical information on optimal timing of the IFNγ-treatment, −tolerance, −effectiveness and outcome before performing a RCT. We describe the effects of IFNγ in a cohort of 18 adult and 2 pediatric sepsis patients.

Methods

In this open-label prospective multi-center case-series, IFNγ treatment was initiated in patients selected on clinical and immunological criteria early (< 4 days) or late (> 7 days) following the onset of sepsis. The data collected in 18 adults and 2 liver transplanted pediatric patients were: clinical scores, monocyte expression of HLA-DR (flow cytometry), lymphocyte immune-phenotyping (flow cytometry), IL-6 and IL-10 plasma levels (ELISA), bacterial cultures, disease severity, and mortality.

Results

In 15 out of 18 patients IFNγ treatment was associated with an increase of median HLA-DR expression from 2666 [IQ 1547; 4991] to 12,451 [IQ 4166; 19,707], while the absolute number of lymphocyte subpopulations were not affected, except for the decrease number of NK cells 94.5 [23; 136] to 32.5 [13; 90.8] (0.0625)]. Plasma levels of IL-6 464 [201–770] to 108 (89–140) ng/mL (p = 0.04) and IL-10 from IL-10 from 29 [12–59] to 9 [1–15] pg/mL decreased significantly. Three patients who received IFNγ early after ICU admission (<4 days) died. The other patients had a rapid clinical improvement assessed by the SOFA score and bacterial cultures that were repeatedly positive became negative. The 2 pediatric cases improved rapidly, but 1 died for hemorrhagic complication.

Conclusion

Guided by clinical and immunological monitoring, adjunctive immunotherapy with IFNγ appears well-tolerated in our cases and improves immune host defense in sepsis induced immuno suppression. Randomized clinical studies to assess its potential clinical benefit are warranted.

Assessment of plasma B7-H3 levels in pediatric patients with different degrees of surgical stress

Background

Surgical stress initiates a series of host hormone, metabolism and immune responses, which predominantly affect the homeostatic mechanism of patients with major surgery. B7-H3 is a co-stimulatory molecule and has been shown to participate in both adaptive and innate immune responses. In this study we evaluated the clinical significance of plasma B7-H3 levels in pediatric patients with different types of operation and degrees of surgical stress.

Methods

A total of 48 children received pediatric general and cardiac surgery were recruited into this study. Based on the surgical stress scoring, children were divided into moderate stress (n = 14) and severe stress (n = 34) groups. Plasma B7-H3 levels were assessed at selected time points: before surgery, immediately after surgery, at day 1, day 3, and day 7 after surgery. Correlations between plasma B7-H3 levels and surgical stress scores were also examined.

Results

Plasma B7-H3 levels were significantly decreased in all 48 pediatric patients after surgery compared to the B7-H3 level before surgery (p < 0.01). Children with general surgery showed significant decreases in plasma B7-H3 immediately after surgery, and at day 3 and day 7 after surgery (p < 0.05, p < 0.01), whereas children with cardiac surgery showed reduced plasma B7-H3 immediately after surgery and at day 3 after surgery (p < 0.05). Plasma B7-H3 in cardiac surgery group was dropped much lower than that in general surgery group at day 1 (p < 0.05) and day 3 (p < 0.01) after surgery. Significantly reduced plasma B7-H3 was observed in the severe stress group, but not in the moderate stress group, immediately after surgery and at day 3 after surgery (p < 0.05), and severe stress group had significantly lower plasma B7-H3 levels than moderate stress group at day 1, day 3, and day 7 after surgery (p < 0.05). Furthermore, plasma B7-H3 levels at day 1 (p = 0.01) and day 3 (p = 0.025) after surgery correlated negatively with surgical stress scores.

Conclusions

Plasma B7-H3 levels were decreased significantly in children subjected to pediatric general and cardiac surgery, which is closely associated with the severity of surgical stress. The negative correlation of plasma B7-H3 levels at day 1 and day 3 after surgery with surgical stress scoring implicates that the plasma B7-H3 level might be a useful biomarker for monitoring stress intensity during pediatric surgery.

Monocytes with angiogenic potential are selectively induced by liver resection and accumulate near the site of liver regeneration

Background

Monocytes reportedly contribute to liver regeneration. Three subsets have been identified to date: classical, intermediate, non-classical monocytes. The intermediate population and a subtype expressing TIE2 (TEMs) were suggested to promote angiogenesis. In a clinical setting, we investigated which monocyte subsets are regulated after liver resection and correlate with postoperative liver function.

Methods

In 38 patients monocyte subsets were evaluated in blood and subhepatic wound fluid by flow cytometry before and 1-3 days after resection of colorectal liver metastases. The monocyte-regulating cytokines macrophage colony stimulating factor (M-CSF), transforming growth factor beta 1 (TGFβ1), and angiopoietin 2 (ANG-2) were measured in patient plasma by ELISA. C-reactive protein (CRP) and liver function parameters were retrieved from routine hospital analyses.

Results

On post-operative day (POD) 1 blood monocytes shifted to significantly elevated levels of intermediate monocytes. In wound fluid, a delayed surge in intermediate monocytes was detected by POD 3. Furthermore, TEMs were highly enriched in wound fluid as compared to circulation. CRP and M-CSF levels were substantially increased in patient blood after surgery and correlated significantly with the frequency of intermediate monocytes. In addition, liver function parameters showed a significant association with intermediate monocyte levels on POD 3.

Conclusions

The reportedly pro-angiogenic subsets of monocytes are selectively increased upon liver resection and accumulate next to the site of liver regeneration. As previously proposed by in vitro experiments, the release of CRP and M-CSF may trigger the induction of intermediate monocytes. The correlation with liver parameters points to a functional involvement of these monocyte populations in liver regeneration which warrants further investigation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12865-014-0050-3) contains supplementary material, which is available to authorized users.

Comparison of a standard CO₂ pressure pneumoperitoneum insufflator versus AirSeal: study protocol of a randomized controlled trial

Background

AirSeal™ is a novel class of valve-free insufflation system that enables a stable pneumoperitoneum with continuous smoke evacuation and carbon dioxide (CO₂) recirculation during laparoscopic surgery. Comparison data to standard CO₂ pressure pneumoperitoneum insufflators is scarce. The aim of this study is to evaluate the potential advantages of AirSeal™ compared to a standard CO₂ insufflator.

Methods/Design

This is a single center randomized controlled trial comparing elective laparoscopic cholecystectomy, colorectal surgery and hernia repair with AirSeal™ (group A) versus a standard CO₂ pressure insufflator (group S). Patients are randomized using a web-based central randomization and registration system. Primary outcome measures will be operative time and level of postoperative shoulder pain by using the visual analog score (VAS). Secondary outcomes include the evaluation of immunological values through blood tests, anesthesiological parameters, surgical side effects and length of hospital stay. Taking into account an expected dropout rate of 5%, the total number of patients is 182 (n = 91 per group). All tests will be two-sided with a confidence level of 95% (P <0.05).

Discussion

The duration of an operation is an important factor in reducing the patient’s exposure to CO₂ pneumoperitoneum and its adverse consequences. This trial will help to evaluate if the announced advantages of AirSeal™, such as clear sight of the operative site and an exceptionally stable working environment, will facilitate the course of selected procedures and influence operation time and patients clinical outcome.

Trial registration

ClinicalTrials.gov NCT01740011, registered 23 November 2012.

Changes in monoclonal HLA-DR antigen expression in acute organophosphorus pesticide-poisoned patients

The aim of this study was to investigate changes in human leukocyte antigen (HLA)-DR expression of peripheral blood mononuclear cells (MNCs) in patients with acute organophosphorus pesticide poisoning (AOPP). HLA-DR antigen expression of peripheral blood MNCs was examined in 75 patients with AOPP, including 36 patients without multiple organ dysfunction syndrome (non-MODS) and 39 patients with multiple organ dysfunction syndrome (MODS), as well as in 30 healthy individuals using flow cytometry assay. The associations between HLA-DR antigen expression and certain parameters were analyzed, including acute physiology and chronic health evaluation II (APACHE II) score, serum cholinesterase (ChE) activity, cardiac troponin I (cTnI), cardiac enzymes, and liver and kidney function. The mean fluorescence intensity (MCF) of HLA-DR expression in the AOPP group (21.59±5.36) was significantly lower than that in the control group (27.85±4.86) (P<0.001). The MCF in the MODS group (18.17±4.23) was lower than that in the non-MODS group (25.15±6.15). In addition, the MCF of the deceased patients (15.29±3.97) was lower than that of the surviving patients (22.34±2.76) (P<0.001). The MCF of patients with AOPP and MODS was positively correlated with serum ChE (P<0.01) and negatively correlated with the APACHE II score, creatine kinase isoenzyme, cTnI, lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen and serum creatinine (P<0.05). In conclusion, HLA-DR expression in patients with AOPP was significantly decreased compared with that in healthy individuals; HLA-DR expression may therefore be a good indicator for evaluating AOPP, MODS disease severity, immune function, efficacy of prognosis and prognosis. Examination of HLA-DR antigen expression may be of crucial clinical value.

CD14, CD16 and HLA-DR reliably identifies human monocytes and their subsets in the context of pathologically reduced HLA-DR expression by CD14(hi) /CD16(neg) monocytes: Expansion of CD14(hi) /CD16(pos) and contraction of CD14(lo) /CD16(pos) monocytes in acute liver failure

Changes in monocytes and their subsets (CD14(hi)/CD16(neg), CD14(hi)/CD16(pos) and CD14(lo)/CD16(pos)) have been described in several diseases. The combination of CD14, CD16 and HLA-DR has been suggested to discriminate monocytes from the CD16(pos) /HLA-DR(neg) NK-cells and neutrophils but no data exist whether this strategy can be used in situations when monocyte HLA-DR expression is pathologically reduced. Monocytes and their subsets were concurrently identified through negative (exclusion of CD66b(pos) neutrophils, CD56(pos) NKcells, CD19(pos) B-cells, and CD3(pos) T-cells) and positive gating (inclusion of monocytes by expression of CD14, CD16, and HLA-DR) strategies on 30 occasions [9 healthy controls (HC) and 21 patients with conditions associated with low monocyte HLA-DR expression]. Bland-Altman and Passing and Bablok regression statistics did not demonstrate any significant measurement bias between the two strategies of monocyte identification. Monocyte subset phenotype was then compared in 18 HC and 41 patients with acute liver failure (ALF). Compared with HC, in ALF, the percentage of CD14(hi)/CD16(pos) monocytes was higher (7% vs 4%) whilst the percentage of CD14(lo)/CD16(pos) was lower (1.9% vs. 7%) (P ≤ 0.001); HLA-DR and CD86 MFIs on all monocyte subsets were lower, whilst CCR5, CD64, and CD11b MFIs were higher (P < 0.05). The relative expression by monocyte subsets of HLA-DR, CCR2, CCR5, CX3CR1, and CD11a was similar in ALF patients and HCs. Repeat analysis of an identical antibody-fluorochrome "backbone" targeting HLA-DR, CD14, and CD16 was assessed in 189 samples across 5 different experiments. There was excellent agreement in the results obtained using the positive gating strategy (interclass correlation coefficients > 0.8). Monocytes and their subsets can be reliably identified using an antibody-fluorochrome "backbone" of HLA-DR, CD14, and CD16. CD16(pos) monocytes continue to constitutively express HLA-DR even in conditions where HLA-DR is pathologically reduced on CD14(hi)/CD16(neg) monocytes. Understanding the changes in monocyte pheontype in ALF and similar clinico-pathological diseases may allow the development of novel biomarkers or therapeutic strategies.

Effects of surgical stress on early nonspecific immune response in children

Surgery alters the body's homeostatic balance and defense mechanisms. In adults transient postoperative cellular and humoral immunosuppression after different degrees of operative stress has been reported. In children the immunologic consequences of operations are not elaborated. This study investigates the effect of minor and major surgery on early nonspecific immune response in terms of neutrophil counts and function. Forty-three children undergoing minor and major elective procedures were studied. Blood samples were collected before, immediately after, and 72 h after surgery. Total white cell count, differential neutrophil count, and neutrophil phagocytic function were studied using nitroblue tetrazolium test. Children were divided into two groups-group 1 underwent minor surgery and group 2 major surgery. In group 1 there was a significant drop in total counts after surgery, but in group 2 total counts were not affected. In both groups, the percentage of neutrophils increased immediately after surgery but fell to near or less than preoperative levels 72 h after surgery. However, the assessment of neutrophil functions by nitroblue tetrazolium test in both unstimulated and stimulated forms revealed it to be unchanged in group 1. In group 2 the unstimulated neutrophil function was elevated 72 h after surgery, whereas stimulated function was elevated immediately after surgery. Minor surgery does not alter the early nonspecific immune response. However, major surgery seems to induce a transient increase in neutrophil phagocytic activity.

Interaction of current cancer treatments and the immune system: implications for breast cancer therapeutics

Early diagnosis and treatment of breast cancer may account for the current improvement in the mortality of breast cancer. However, achieving a complete 'cure' is the holy grail of cancer medicine and, in many cases, cancer patients still succumb to their ultimate fate. There is therefore a need to devise innovative therapies to overcome this problem. To this end, many emerging therapies utilizing the immune system to eradicate the residues of disease have been described in the preclinical and clinical arenas. However, there is very little work examining the impact of immunotherapy on the existing natural immunity. The relationship between antitumor immunity, in the form of immunotherapy (either passive or active), and current strategies of treatment also needs to be explored. If we are to improve the success of cancer treatment, we must understand how current therapies interact with the immune system and with the emerging immunotherapies. For breast-cancer treatment to be successful, therapeutics should be tailored towards antitumor immunity; they should also avoid tumor-specific tolerance. The sources of information used to prepare this paper were obtained through published work on Pubmed/Medline and materials published on the US/UK governmental agencies' websites.

Decreased monocyte class II MHC expression following major abdominal surgery in children is related to operative stress

Monocyte class II major histocompatibility complex (MHC) expression is necessary for antigen presentation and stimulation of T-cells. The aim of this study was to correlate monocyte class II MHC response to operative stress in children and the possible influence of cytokines in the postoperative period. We studied 21 children undergoing elective abdominal surgery. Operative stress score (OSS) was calculated. Monocyte class II MHC expression was measured preoperatively, immediately after surgery, 24 and 48 h postoperatively, using flow cytometry. Class II MHC is expressed as mean fluorescence intensity (MFI) of monocytes expressing MHC (mean +/- SD). Cytokine levels (interleukins 1ra, 6, and 10, and tumor necrosis factor-alpha) were also measured. Data between time points were compared using repeated measures ANOVA. There was an immediate postoperative decrease in class II MHC expression, with lowest levels 24 h postoperatively (preoperative 50 +/- 23.6, 24 h 18.2 +/- 9.4, P < 0.0001 vs. preoperative). At 48 h there was partial recovery in class II MHC, but levels were still significantly lower than preoperative (23.9 +/- 11.1, P < 0.001). The degree of monocyte depression was related to the magnitude of operative stress. Patients who had OSS <10 displayed some recovery in expression at 48 h 25.5 +/- 11.1), whereas in patients with OSS > or = 10 (severe surgical stress), expression further decreased at 48 h (MFI 14.0 +/- 0.1). There was an elevation of interleukin-1ra in the immediate postoperative period in both groups. There was no elevation in the other cytokines. Abdominal surgery in children decreases monocyte MHC expression. Class II MHC depression was related to magnitude of surgical trauma, implying that more severe immuneparesis follows surgery of greater magnitude. This may predispose to postoperative infection.

Intraoperative splanchnic hypoperfusion, increased intestinal permeability, down-regulation of monocyte class II major histocompatibility complex expression, exaggerated acute phase response, and sepsis

BACKGROUND

A compromised gut barrier function may be associated with systemic inflammatory response syndrome, sepsis, and multiple organ dysfunction syndrome in patients after major trauma or critical illness, and inadequate oxygenation of the gut mucosa has been incriminated as an underlying mechanism. The focus of this study was the relationship of splanchnic hypoperfusion to regional and systemic immune responses after major surgery.

METHODS

Patients (n=20) undergoing curative oncologic resection of the esophagus or esophagogastric junction were studied. Gastric mucosal pH level was monitored by gastric tonometry. The expression of class II major histocompatibility complex antigen (human leukocyte antigen-DR) and L-selectin on systemic monocytes was assessed before surgery, during surgery (as well as portal monocytes), and for 1 week after surgery, along with C-reactive protein levels. Intestinal permeability was measured before surgery and on the first and seventh postoperative days by using dual sugar probes.

RESULTS

Significant mucosal acidosis (pH<7.1) intraoperatively was evident in 5 patients (25%), and a further 7 patients (35%) had a nadir gastrointestinal mucosal pH level between 7.1 and 7.2. Severe (<7.1) mucosal acidosis was associated significantly (P< .05) with postoperative septic complications, an increase in postoperative intestinal permeability, C-reactive protein and L-selectin expression, and a decrease (P< .05) in monocyte human leukocyte antigen-DR expression.

CONCLUSIONS

Intraoperative splanchnic hypoperfusion is associated significantly with down-regulation of monocyte function, increased intestinal permeability, and an exaggerated acute phase response. This suggests that splanchnic hypoperfusion alters local and systemic immune function, supporting the thesis that the gut has a central role in the immunoinflammatory response to major surgery.

Endoscopic treatment of thoracic esophageal anastomotic leaks by using silicone-covered, self-expanding polyester stents

BACKGROUND

Surgery, as well as conservative treatment, in patients with clinically apparent intrathoracic esophageal anastomotic leaks often is associated with poor results and carries a high morbidity and mortality. The successful treatment of esophageal anastomotic insufficiencies and perforations when using covered, self-expanding metallic stents is described.

METHODS

The feasibility and the outcome of endoscopic treatment of intrathoracic anastomotic leakages when using silicone-covered self-expanding polyester stents were investigated. Twelve consecutive patients presented with clinically apparent intrathoracic esophageal anastomotic leak caused by resection of an epiphrenic diverticulum (n = 1), esophagectomy for esophageal cancer (n = 9), or gastrectomy for gastric cancer (n = 2), were endoscopically treated in our department. The extent of the dehiscences ranged from about 20% to 70% of the anastomotic circumference. After endoscopic lavage and debridement of the leakage at 2-day intervals (mean duration, 8.6 days), a large-diameter polyester stent (Polyflex; proximal/distal diameters 25/21 mm) was placed to seal the leakage. Simultaneously, the periesophageal mediastinum was drained by chest drains.

OBSERVATIONS

All 12 patients were successfully treated endoscopically without the need for reoperation. A complete closure of the leakage was obtained in 11 of 12 patients after stent removal (median time to stent retrieval, 4 weeks, range 2-8 weeks). In one patient, a persistent leak was sealed endoscopically after stent removal by using 3 clips. Distal stent migration was obtained in two patients.

CONCLUSIONS

The placement of silicone-covered self-expanding polyester stents seems to be a successful minimally invasive treatment option for clinically apparent intrathoracic esophageal anastomotic leaks.

Inflammatory response in children after laparoscopic vs open Nissen fundoplication: randomized controlled trial

We performed a randomized controlled trial to compare the inflammatory and immune responses to Nissen fundoplication in infants and children undergoing either open or laparoscopic surgery.

METHODS

Forty children undergoing Nissen fundoplication were randomized to laparoscopy or open surgery using minimization with respect to age, neurologic status, and operating surgeon. Intraoperative and postoperative analgesias were standardized. Inflammatory markers (plasma malondialdehyde, nitrate plus nitrite level, and cytokines) and monocyte class II major histocompatibility complex expression were measured preoperatively, at end of surgery, 4, 24, and 48 hours postoperatively. Postoperative changes were compared between open and laparoscopic groups.

RESULTS

There were no significant changes in circulating malondialdehyde, nitrates plus/ nitrite, interleukin-10, or tumor necrosis factor alpha in the postoperative period in either group. Interleukin-1 receptor antagonist (IL-1rA) and IL-6 were significantly increased in both groups, with a tendency for greater elevation of IL-1rA in the open group. Monocyte major histocompatibility complex expression fell significantly in both groups; however, this fall appeared to be slightly more marked in the open group.

CONCLUSIONS

The postoperative cytokine response is similar in children undergoing open and laparoscopic Nissen fundoplication. This trial indicates that laparoscopy may partly reduce postoperative immune suppression.

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.

Interferon-γ increases monocyte HLA-DR expression without effects on glucose and fat metabolism in postoperative patients

Tissue injury is associated with decreased cellular immunity and enhanced metabolism. Immunodepression is thought to be counteracted by interferon (IFN)-γ, which increases human leukocyte antigen (HLA)-DR expression. Hypermetabolism could be enhanced by IFN-γ because cytokines induce a hypermetabolic response to stress. In healthy humans, IFN-γ enhanced HLA-DR expression without effects on glucose and fat metabolism. In the present study, we evaluated whether IFN-γ lacks potential harmful side effects on metabolic and endocrine pathways while maintaining its beneficial effects on the immune system under conditions in which the inflammatory response system is activated. In 13 patients scheduled for major surgery, we studied HLA-DR expression on peripheral blood monocytes before surgery and postoperatively randomized the patients into an intervention and a placebo group. Subsequently, we evaluated the effects of a single dose of IFN-γ vs. saline on short-term monocyte activation, glucose and lipid metabolism, and glucose and lipid regulatory hormones. HLA-DR expression on monocytes was restored from postoperative levels of 54% (42-60%; median and interquartiles) to 92% (91-96%) 24 h after IFN-γ adminstration but stayed low in the placebo-treated patients. IFN-γ did not affect glucose metabolism (plasma glucose, rate of appearance and dissappearance of glucose) and lipid metabolism (plasma glycerol, plasma free fatty acids, and rates of appearance and disappearance of glycerol). IFN-γ had no effect on plasma cortisol, adrenocorticotropic hormone, growth hormone, insulin, C-peptide, glucagon, epinephrine, and norepinephrine concentrations. We conclude that IFN-γ exerts a favorable effect on cell-mediated immunity in patients after major surgery without effects on glucose and lipid metabolism.

Monocyte and neutrophil activity after minor surgical stress

BACKGROUND/PURPOSE

Surgical stress produces changes in the immune status of patients. In adults, major surgery causes immunosuppression, whereas minor operations stimulate immune responses. In children, the immunologic response to surgery has not been elucidated completely. The authors investigated the effects of minor surgery on immune response by analyzing neutrophil and monocyte phagocytosis and oxidative burst activity.

METHODS

Sixteen children undergoing elective minor surgery were enrolled. Blood samples were collected before the operation (at time of induction of anesthesia), at the end of operation, and 72 hours after surgery. Neutrophil and monocyte phagocytosis and oxidative burst activity were studied using a flow cytometric method.

RESULTS

Phagocytosis and oxidative burst increased significantly at the end of the operation, both in neutrophils (7.4% and 14.3%, respectively) and monocytes (11.6% and 27%, respectively). The increase was only significant for monocytes (17.5%) 72 hours after surgery. White cell count did not show any significant changes. There was no significant correlation between phagocytosis, oxidative burst activity, and white cell count or neutrophil and monocyte count.

CONCLUSIONS

This study shows that minor surgery in children induces immune activation by increasing neutrophil and monocyte phagocytosis and oxidative burst activity. Further studies are required to understand the molecular basis of these findings.

Influence of surgery and endotoxin-induced sepsis combined on natural killer cell activity, oxidative burst of granulocytes and antigen presentation capability of monocytes

BACKGROUND

Cell mediated immunity is affected in the course of sepsis and following surgical stress. The natural killer (NK) cells, the granulocytes and the monocytes constitute the immediate unspecific cell mediated immunity. We therefore investigated the effect of surgery- and endotoxin-induced sepsis on NK cells, granulocytes and monocytes in a two-hit model.

METHODS

Three groups of 40 mice. Each group was divided into four groups of 10 mice. All the animals were anesthetized and subjected to either: laparotomy; treatment with Escherichia coli endotoxin i.p.; laparotomy followed 20 min later by endotoxin i.p.; or left untreated as a control group. In the first 40 mice the NK cell activity in the spleen and number of NK cells in the liver were measured, in the second the oxidative burst of granulocytes, and in the third the antigen presentation capacity of monocytes.

RESULTS

Endotoxin stimulated the NK cell activity and up-regulated the antigen presentation capability on monocytes. In contrast, surgical stress reduced the NK cell activity, the number of NK cells and down-regulated the antigen presentation capability on monocytes. After surgery, followed by administration of endotoxin, the oxidative burst of granulocytes was stimulated while antigen presentation capability on monocytes was down-regulated. Endotoxin prevented or reverted the postoperative suppression of NK cell activity.

CONCLUSION

Our two-hit model shows that some cell types of the unspecific immune system exhibit an excessive inflammatory response (NK cells, granulocytes) while specific functions of other cell types (monocytes) are simultaneously diminished. This diversity makes a potential therapeutic immunomodulation very complex as some cell types would need to be down-regulated while others need to be stimulated.

Acute phase responses following minimal access and conventional thoracic surgery

OBJECTIVES

Major thoracic surgery is associated with trauma-related immunological changes. These may impair anti-tumour immunity. We hypothesize that the reduced operative trauma associated with a video-assisted thoracic surgery (VATS) approach may decrease acute phase responses and, consequently, lead to better preservation of immune function. This prospective randomized study compared the effects of conventional open thoracic surgery and VATS on acute phase responses in patients undergoing pulmonary lobectomy.

METHODS

Acute phase indicators were analyzed in patients undergoing lobectomy for suspected bronchogenic carcinoma. Surgery was prospectively randomized to pulmonary lobectomy by VATS or limited postero-lateral thoracotomy. Blood was taken pre-operatively and at 4, 24, 48, 72, 120 and 168 h post-operatively for analysis of C-reactive protein (CRP; 41 patients: open, n=22; VATS, n=19) interleukin (IL)-6, tumour necrosis factor (TNF) receptors (TNF-sR55, TNF-sR75) and P-selectin (24 patients: open, n=12; VATS, n=12). Samples taken at 48 and 168 h were also analyzed for phagocyte reactive oxygen species (ROS) production (25 patients: open, n=16; VATS, n=19).

RESULTS

Surgery increased acute phase responses. VATS was associated with lower CRP and IL-6 levels. In the open surgery group, significant increases in ROS in neutrophils (up to 36% greater than before surgery, n=12, P<0.02-0.05) were detected at 2 days after surgery, but in the VATS group, the increase after surgery (of up to 17%, n=18) did not reach significance. Similarly, monocyte ROS increases of up to 25% in the mean ROS in the open surgery group and of up to 17% in the VATS group were detected on days 2 and 7 after surgery.

CONCLUSIONS

VATS pulmonary lobectomy is associated with reduced peri-operative changes in acute phase responses. This finding may have implications for peri-operative tumour immuno-surveillance in lung cancer patients.

Interleukin-10 release and monocyte human leukocyte antigen-DR expression during femoral nailing

This study determined the effect of femoral nailing on the expression of monocyte Class II antigens and interleukin-10 release and sought to differentiate any differences in the release of these elements of immune reactivity in patients undergoing reamed and unreamed nailing. Thirty-two patients presenting with an acute femoral fracture were studied. In 15 patients, the femoral fracture was stabilized with a reamed technique and in 17 patients with an unreamed technique. Venous blood samples were taken at presentation, at anesthetic induction, immediately after nail insertion, and subsequently at 1, 4, and 24 hours and at 3, 5, and 7 days after surgery. Serum interleukin-10 was measured by an enzyme-linked immunosorbent assay, and monocyte human leukocyte antigen-DR expression was quantified by flow cytometry. Serum interleukin-10 release and human leukocyte antigen-DR expression on monocytes showed a clear response to the nailing procedure. The group of patients undergoing a reamed femoral nailing procedure showed significantly higher interleukin-10 release and a significant depression in the expression of human leukocyte antigen-DR on monocytes compared with those whose nail had been inserted unreamed. One patient in the reamed femoral nailing group died of adult respiratory distress syndrome 3 days after injury. Reamed intramedullary nailing appears to be associated with greater impairment of immune reactivity than is the unreamed nailing technique.

Endoscopic treatment of clinically symptomatic leaks of thoracic esophageal anastomoses

BACKGROUND

The mortality of thoracic anastomotic leakage following esophageal reconstruction has been reported to be as high as 60%. Early septic fulminant suture line leaks require rethoracotomy. In addition, however, clinically symptomatic leaks may also occur 2 to 7 days after resection of the esophagus.

METHODS

Among 80 esophageal reconstructions performed between January 1994 and July 1998, a total of 7 (8.75%) clinically apparent leaks of thoracic anastomoses were observed. The standard treatment consisted of endoscopic lavage, drainage and subsequent closure of the defect by repeated intraluminal and submucosal applications of fibrin glue. In 2 patients a novel approach permitting rapid closure by plugging the fistula with a Vicryl-cylinder was tried. In 4 patients the effect of endoscopic treatment on the HLA-DR expression on monocytes was investigated and compared to 6 patients with intact anastomoses.

RESULTS

All 7 patients were successfully treated via endoscopy. The cylinder plug achieved immediate closure of the leak. The measured change in HLA-DR expression reflected the improvement in the inflammatory response and thus documented the success of endoscopic treatment.

CONCLUSIONS

Endoscopic management of thoracic leakages represents a safe and relatively noninvasive therapeutic option.