The effect of treating infected skin grafts with Acticoat™ on immune cells

A study was conducted to determine the effect of Acticoat placed on an infected skin graft on parameters of immunity. Two partial thickness wounds (2 cm x 4 cm) were created on the dorsal midline of Hartley guinea pigs (n=28). Wounds were covered with autologous skin graft and maintained either aseptically (Noninoculated, n=8), inoculated with Staphylococcus aureus (Surgery-Inoculated, n=8) with or without Acticoat bandage (Surgery-Inoculated-Acticoat, n=6). Five days later, splenocytes and blood were collected to estimate natural killer cell (NK) cytotoxicity, proliferative response to T and B cell mitogens and neutrophil oxidative burst. Animals that did not undergo surgery were included as a nonsurgery control group. [(3)H]-thymidine incorporation in response to a variety of T and B cell mitogens was significantly lower for all groups undergoing surgery compared to the nonsurgery control group (p<0.0001) and no additional effect was observed on this immune measure by applying the Acticoat bandage. The Surgery-Inoculated-Acticoat group exhibited greater NK cytotoxic activity (as assessed as the ability to lyse K562 tumor cells) compared to the Surgery-Inoculated group (p<0.006). The Surgery-Inoculated-Acticoat group had higher neutrophil oxidative burst at 5 min post stimulation, but was not different from controls after 15 min. In conclusion, the application of an Acticoat bandage to an inoculated surgery wound did not alter the low cell-mediated immune response that followed surgery, but appeared to increase parameters (NK cytotoxic activity and neutrophil function) of innate immunity.

Aggressive management of surgical emergencies

Increasing evidence suggests that two factors significantly influence outcome in a surgical emergency - premorbid health and the degree of inflammation during the first 24 h following trauma. Repeat observations suggest that the depth of post-trauma immunoparalysis reflects the height of early inflammatory response. Administration to surgical emergencies, as was routine in the past, of larger amounts of fluid and electrolytes, fat, sugar and nutrients seems counterproductive as it increases immune dysfunction, impairs resistance to disease and, in fact, increases morbidity. Instead, strong efforts should be made to limit the obvious superinflammation, which occurs during the first 24 h after trauma and, thereby, reduce the subsequent immunoparalysis. Several approaches show efficacy in limiting early superinflammation such as strict control of blood glucose, avoidance of stored blood when possible, supply of antioxidants, live lactic acid bacteria and plant fibres. This review focuses mainly on use of live lactic acid bacteria and plant fibres, often called synbiotics. Encouraging experience is reported from clinical trials in liver transplantation, severe pancreatitis and extensive trauma. Immediate control of inflammation by enteral nutrition and supply of antioxidants, lactic acid bacteria and fibres is facilitated by feeding tubes, introduced as early as possible on arrival at the hospital.

[Prediction of surgical infections severity at elderly and old patients]

Clinical and immunological characteristics of generalized peritonitis in different age group at complicated and non-complicated postoperative period were analyzed at 246 patients with abdominal purulent infection. Prognostic criteria of complicated postoperative period at elderly and old patients have been determined. It is concluded that interpretation of immune characteristics permits to determine the prognostic criteria of disease course and outcome at various age group, and to use the rational immunocorrection.

Clinical inquiries. Which vaccinations are indicated after splenectomy?

Immunization against encapsulated bacterial pathogens decreases the incidence of post-splenectomy sepsis. Pneumococcal, meningococcal, and Haemophilus influenzae (Hib) vaccinations are indicated for patients after splenectomy. These immunizations should be given at least 14 days before a scheduled splenectomy, or given after the fourteenth postoperative day (strength of recommendation [SOR]: A, based on systematic review of RCTs for the pneumococcal vaccine; SOR: B, based on systematic review of clinical trials for meningococcal and Hib vaccines).

Mediator Responses in Surgical Infections

BACKGROUND

Surgical infections, and sepsis in particular, are characterized by extensive release of mediators. Our laboratories have been interested in understanding how these substances contribute to morbidity and mortality during various stages of surgical infections in order to develop new and more effective therapeutics and treatment strategies.

METHODS

In a series of in vitro studies, human plasma was exposed to lipopolysaccharide (LPS), and whole blood was treated with peptidoglycan from Staphylococcus aureus. The activity of peptidoglycan also was studied in the rat, and LPS infusion was tested in dog and pig models. In a clinical study, the relation of serum LPS to multiple organ dysfunction and failure was studied in patients in the surgical intensive care unit.

RESULTS

Exposure of plasma to LPS led to formation of bradykinin, activation of the plasma kallikrein-kinin system, and reduction of kallikrein inhibitor capacity. The coagulation, fibrinolysis, and complement cascades were activated. Peptidoglycan caused rapid release of tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 from macrophages and activation of the genes encoding pro-inflammatory and anti-inflammatory cytokines. In the rat, peptidoglycan induced cytokine release, caused liver and kidney dysfunction, and induced matrix metalloproteinase-9 (MMP-9) activity in the liver and lung. In the dog and pig, LPS caused substantial activation of plasma proteases. Clinically, a finding of LPS in the plasma was associated with multiple organ dysfunction and failure. These patients also revealed substantial activation of the plasma cascade systems, as well as systemic cytokine release.

CONCLUSION

On the basis of these observations, we developed a monitoring system to recognize early signs of infection.

CD4+ T cells and CXC chemokines modulate the pathogenesis of Staphylococcus aureus wound infections

T cells are critical for the formation of intraabdominal abscesses by Staphylococcus aureus. We hypothesized that T cells modulate the development of experimental staphylococcal infections by controlling polymorphonuclear leukocyte (PMN) trafficking. In models of staphylococcal s.c. abscess formation, hindpaw infection, and surgical wound infection, S. aureus multiplied in the tissues of WT C57BL/6J mice and elicited a marked inflammatory response. CD4(+) alphabeta T cells homed to the surgical wound infection site of WT animals. In contrast, significantly fewer S. aureus were recovered from the tissues of mice deficient in alphabeta T cells, and the inflammatory response was considerably diminished compared with that of WT animals. Alphabeta T cell receptor (-/-) mice had significantly lower concentrations of PMN-specific CXC chemokines in wound tissue than did WT mice. The severity of the wound infection was enhanced by administration of a CXC chemokine and abrogated by antibodies that blocked the CXC receptor. An acapsular mutant was less virulent than the parental S. aureus strain in both the s.c. abscess and the surgical wound infection models in WT mice. These data reveal an important and underappreciated role for CD4(+) alphabeta T cells in S. aureus infections in controlling local CXC chemokine production, neutrophil recruitment to the site of infection, and subsequent bacterial replication.

Increased plasma levels of IL-6 and IL-8 are associated with surgical site infection after pancreaticoduodenectomy

OBJECTIVES

Cytokines and chemokines potentially modulate postoperative immune response. Association of circulating cytokines and chemokines with postoperative infectious complications after pancreaticoduodenectomy was evaluated.

METHODS

Plasma concentrations of interleukin (IL) 6, IL-10, IL-8, macrophage chemoattractant protein 1, heat shock protein 70, and amylase, as well as amylase levels in peritoneal exudative fluid, were measured perioperatively in 60 consecutive patients who underwent pancreaticoduodenectomy.

RESULTS

Of the 60 patients, 27 patients had surgical site infection (SSI), including peritoneal infection in all, intra-abdominal abscess in 14, and radiologically visualized pancreatic leakage in 6. Postoperative plasma levels of IL-6, IL-8, and macrophage chemoattractant protein 1, as well as peritoneal amylase levels, were significantly higher in patients with SSI than in those without SSI (P < 0.05). Nonpancreatic cancer as a histopathologic diagnosis, high pancreatic juice flow, and increased levels of IL-6 and IL-8 were independently associated with SSI (P < 0.05) in multiple logistic regression analysis. Plasma levels of IL-6 and IL-10 among patients with SSI were significantly higher in those with pancreatic leakage than in those without leakage.

CONCLUSIONS

These results suggest that, in addition to pancreatic exocrine function, IL-6 and IL-8 are associated with postoperative SSI, including pancreatic leakage after pancreaticoduodenectomy.

[Status of immune response and possibilities of its correction during the severe surgical infections of the maxillo-facial region]

The study of the immune status of the 30 patients with suppurative-septic diseases of the maxillo-facial region reveal the marked changes such as the deviation of the functions of antigen-presenting cells (macrophages, monocytes). The antigen specific immune-response system is disturbed as well (CD4+, CD8+); the production of the protective immune globulins (B cells) is abnormal. The serious suppression of interferon system occurs (suppression of the activities of INFalpha and INFgamma). The cytokine therapy using the Ronkoleukine, in association with systemic antibacterial therapy (patients with the severe forms of surgical infection of maxillo-facial region) during the 10-12 days markedly improve deviation of the immune status. It diminishes the degree of the endogen toxemia and reduces the time of recovery.

[The influence of trauma on immunological response (the role of Tgammadelta+ lymphocytes)]

The influence of trauma, especially surgical operation on immunological response has not been clarified sufficiently. The authors discuss the influence of surgical trauma on humoral and cell mediated immune response and on phagocytosis as well. The role of Tgammadelta+ lymphocytes in immunological processes that occur after trauma have been also discussed.

Deficiency in systemic interleukin-1 receptor antagonist production as an operative risk factor in malnourished elderly patients with colorectal carcinoma

OBJECTIVE

Aging and tumor-related malnutrition are associated with increased inflammatory cytokine levels. However, it is unclear whether this influences the outcomes of surgery. We explored the relationships between cytokines and surgical complications among patients undergoing surgery for colorectal cancer.

DESIGN

Laboratory experiment.

SETTING

Surgery department of school of medicine.

PATIENTS

One hundred patients with colorectal cancer.

INTERVENTIONS

The perioperative circulating levels of interleukin (IL)-1beta, IL-6, and IL-1 receptor antagonist (Ra) were determined, and the numbers of circulating lymphocytes and neutrophils were counted.

MEASUREMENTS AND MAIN RESULTS

Trends toward increasing postoperative infection were observed among patients who were older and had lower body mass index. Preoperative IL-1Ra and intraoperative blood loss, however, remained the only two independent predictors of postoperative infection. Clinically, patients with low preoperative IL-1Ra most frequently were the elderly with low body mass index. Postoperatively, elderly patients with low body mass index showed an exaggerated IL-6 response, followed by an exaggerated postoperative inflammatory response and increased postoperative loss of body weight. In contrast, normal immunoreactivity was preserved in well-nourished elderly patients.

CONCLUSIONS

In colorectal cancer patients undergoing surgery, low preoperative IL-1Ra is associated with postoperative infection. In our patient population, lower IL-1Ra level is commonly observed in the elderly with low body mass index. These findings suggest that postoperative infection, frequently seen in the nutritionally deficient elderly, may be the result of defective immunoinflammatory adaptation system.

Postoperative spondylodiscitis from Aspergillus fumigatus in immunocompetent subjects

The authors describe a case of spondylodiscitis from Aspergillus fumigatus which occurred subsequent to surgery for lumbar disc herniation in a non-immunodepressed patient. The results obtained by combined medical and surgical treatment are discussed.

Altered Cell-mediated Immunity and Increased Postoperative Infection Rate in Long-term Alcoholic Patients

Background

Preoperative alteration of T cell-mediated immunity as well as an altered immune response to surgical stress were found in long-term alcoholic patients. The aim of this study was to evaluate perioperative T cell-mediated immune parameters as well as cytokine release from whole blood cells after lipopolysaccharide stimulation and its association with postoperative infections.

Methods

Fifty-four patients undergoing elective surgery of the aerodigestive tract were included in this prospective observational study. Long-term alcoholic patients (n = 31) were defined as having a daily ethanol consumption of at least 60 g and fulfilling the Diagnostic and Statistical Manual of Mental Disorders for either alcohol abuse or alcohol dependence. The nonalcoholic patients (n = 23) were defined as drinking less than 60 g ethanol/day. Blood samples to analyze the immune status were obtained on morning before surgery and on the morning of days 1, 3, and 5 after surgery.

Results

Basic patient characteristics did not differ between groups. Before surgery, the T helper 1:T helper 2 ratio (Th1: Th2) was significantly lower (P &lt; 0.01), whereas plasma interleukin 1beta and lipopolysaccharide-stimulated interleukin 1ra from whole blood cells were increased in long-term alcoholic patients. After surgery, a significant suppression of the cytotoxic lymphocyte ratio (Tc1:Tc2), the interferon gamma:interleukin 10 ratio from lipopolysaccharide-stimulated whole blood cells, and a significant increase of plasma interleukin 10 was observed. Long-term alcoholics had more frequent postoperative infections compared with nonalcoholic patients (54%vs. 26%; P = 0.03).

Conclusions

T helper cell-mediated immunity was significantly suppressed before surgery and possibly led to inadequate cytotoxic lymphocyte and whole blood cell response in long-term alcoholic patients after surgery. This altered cell-mediated immunity might have accounted for the increased infection rate in long-term alcoholic patients after surgery.

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.

[Use of cytomedins in combined therapy of surgical infections]

Under study was the influence of cytomedins on the system of immunity in patients with developed surgical infection in a traumatology clinic. The investigation of immune reactions under conditions of purulent infection of different etiology has shown the necessity to include the up-to-date and purposeful immunomodulating therapy (cytomedins) in the complex of treatment which allows arrest of the inflammatory process in the wound in earlier terms.

Postoperative pneumococcal cellulitis in systemic lupus erythematosus

This paper reports a case of nosocomial pneumococcal cellulitis that developed following a lymph-node biopsy in a woman being treated with high-dose intravenous corticosteroids for systemic lupus erythematosis (SLE). Her rapid and severe clinical deterioration was similar to that caused by group A streptococcus. The risk factors for the development of nosocomial pneumococcal cellulitis as a complication of SLE are reviewed and preventive measures discussed.

Cellular, biochemical, and clinical aspects of wound healing

BACKGROUND

The response to tissue injury requires the symphonious interaction of immune cells, keratinocytes, fibroblasts, and endothelial cells, which unite to regenerate the damaged epithelium. Recent insights have elucidated the cellular and molecular mechanisms required for wound healing and have raised the prospect of novel therapeutic targets.

METHODS

Review of the pertinent literature.

RESULTS

The initial inflammatory response leads to the influx of macrophages and neutrophils, which release cytokines, growth factors, and nitric oxide, and induce nearby keratinocytes to migrate across the wounded epithelium. This process, known as re-epithelialization, requires integrin-mediated activation of Rho-GTPases. The subsequent influx of fibroblasts and endothelial cells results in the production of tissue stroma and formation of new blood vessels, which lead to the generation of functional tissue. Importantly, disease states associated with impaired or excessive wound healing can be attributed to defects in these responses, providing a rationale for the use of evidence-based biological therapies.

CONCLUSION

The elucidation of the cellular and biochemical response to wound healing is essential for an understanding to the treatment of clinical conditions during which impaired healing is encountered.

Association between patient-controlled analgesia pump use and postoperative surgical site infection in intestinal surgery patients

BACKGROUND

Patient-controlled analgesia (PCA) pumps are widely used after surgery, but their association with various outcomes is not completely understood. Is PCA pump use related to the incidence of postoperative surgical site infections among patients undergoing open intestinal surgery?

MATERIALS AND METHODS

We undertook a comprehensive retrospective chart review of 515 randomly selected patients over age 18 who had major rectal or intestinal surgery (Diagnosis Related Groups [DRGs] 146-149) between January 1994 and March 1997 from eight community or teaching hospitals along the U.S. west coast. Of these patients, 214 used PCA pumps. Outcome measures were in-hospital postoperative surgical site infections, respiratory complications, ileus/abdominal distention, urinary tract infection/urinary retention, and length of stay.

RESULTS

Use of a PCA pump was significantly associated with increased in-hospital postoperative surgical site infections (10.7% for PCA, 4.0% for no PCA). The odds ratio for PCA use was about 4.0 after controlling for many variables, including severity of illness at admission, body mass index, preadmission use of corticosteroids, perforated viscus, number of previous abdominal operations, wound classification category, hypothermia, malnutrition on admission, preoperative antibiotic use within 2 h before incision, time from hospital admission to surgery, skin prep to incision time, anesthesia start to incision time, surgical skin to skin time, wound closure type, time from incision closure to the start of PCA, use of drains, blood product use, central line use, line infection, mobility assistance required, hospital, DRG, and surgeon.

CONCLUSION

No confounding variables explained the significant association between PCA pump use and in-hospital surgical site infection. These results stand firmly on data that merit additional study to further elucidate possible immunologic effects of PCA pumps.

The influence of diabetes mellitus on postoperative infections

Clinicians and researchers are linking elevated glucose levels with potential infectious outcomes. Physiologic processes to fight foreign agents are potentially impaired during periods of hyperglycemia. Some of these responses, such as immune function and the inflammatory response, are impaired when they are needed most, such as during the recovery from surgical procedures. Investigators have demonstrated the importance of control of serum glucose postoperatively. Outcomes are improved when tighter glycemic control is practiced. The current literature challenges practitioners to become more cognizant of serum glucose in surgical patients and patients who are critically ill, implementing protocols to gain tighter control of serum glucose in any patient may be appropriate. Further investigation of glycemic control in surgical and other populations will reinforce research findings in this area. Studies should be performed on surgical patients who are particularly vulnerable to DM, glycemic alterations, and postoperative infections, such as patients undergoing peripheral vascular surgery. Further investigations are also needed on the role of hyperglycemia and outcomes in nondiabetic individuals, and on the similarities or differences in glycemic control in types 1 and 2 DM. To increase the generalizability of the study findings, definitions used across studies, such as the type of diabetes, should be standardized. When these studies determine optimal glycemic control practices in a variety of patient populations, clinicians will be able to determine the best practice guidelines to optimize patient care and limit adverse infectious outcomes.

Immune responses and prediction of major infection in patients undergoing transhiatal or transthoracic esophagectomy for cancer

OBJECTIVE

To investigate alterations in immune responses after transhiatal versus transthoracic esophageal resection and to evaluate the role of preoperative immune functions in predicting postoperative infectious complications.

SUMMARY BACKGROUND DATA

Impaired immune defense is associated with a decreased resistance to infection. Patients undergoing esophageal resection via a transhiatal or transthoracic approach are prone to develop infectious complications. There are no randomized data on immune responses after two major surgical interventions.

METHODS

The study group consisted of 20 patients who were randomly allocated to a limited transhiatal or extended transthoracic esophagectomy for cancer. Blood samples were taken before the operation and at regular intervals thereafter from day 1 to day 10. Monocyte and T-helper type 1 (Th1) and type 2 (Th2) lymphocyte functions were assessed in stimulated whole blood cultures.

RESULTS

Both surgical groups had severely depressed in vitro production of interleukin (IL)-12, IL-10, interferon-gamma, IL-2, IL-4, and IL-13 on postoperative day 1. Depression of Th2-type cytokine production was more profound after transthoracic than after transhiatal esophagectomy (IL-4, P=.005; IL-13,P=.007). Postoperative reduction in Th1-type cytokine production was similar between the two groups (interferon-gamma, P=.40; IL-2, P=.06). Irrespective of the surgical approach, patients who developed major infectious complications after surgery presented with a diminished T-cell cytokine production before the operation compared to those who had a relatively uneventful recovery (IL-4, P=.045; interferon-gamma, P=.064). In regression analysis, the occurrence of postoperative major infection was best predicted by increased duration of anesthesia ( P<.0001) and low preoperative interferon-gamma production ( P=.006).

CONCLUSIONS

Both transhiatal and transthoracic esophagectomy induced severely depressed monocyte and T-lymphocyte cytokine production. The extent of the surgical procedure had a differential immunosuppressive impact on Th2-type but not on Th1-type cell activity, indicating that the two Th pathways were downregulated through distinct mechanisms. Preoperative interferon-gamma determination would be useful to anticipate the occurrence of postoperative major infectious complications.

[Receptors and signal proteins of the innate immune system as new targets in sepsis therapy. Reprogramming of the immune response]

During polymicrobial sepsis,microbial pathogens and their products activate the innate immune system through signaling receptors of the Toll-like receptor (TLR) family, resulting in hyperinflammation and organ injury. The analysis of preclinical mouse models has shown that inactivation of the common TLR signaling adaptor protein MyD88 prevents the hyperinflammatory response and improves survival.Importantly, MyD88 deficiency does not impair antibacterial defense mechanisms.Thus,TLRs and proteins involved in TLR signaling may represent interesting targets for the development of new drugs for reprogramming pathophysiological immune responses during sepsis.