Altered helper and suppressor lymphocyte populations in surgical patients. A measure of postoperative immunosuppression

Cimetidine repurposed as a potential immunomodulatory agent against colorectal carcinoma: A systematic review

OBJECTIVE

To determine the survival benefit and immunomodulatory effects of cimetidine pre-, peri- or post-operatively in patients with colorectal cancer (CRC).

METHODS

A systematic review was conducted using PubMed and Cochrane Library to retrieve randomized control trials (RCTs) that investigated the effects of cimetidine on survival and immunomodulation via improvement in tumor infiltrating lymphocytes (TILs) and peripheral blood lymphocytes. The review was carried out in accordance with the extended Preferred Reporting Items for Systematic Reviews and Meta-analyses.

RESULTS

Four studies with the total of 267 patients were included in this systematic review. Treatment duration varied from 5 days to 1 year. Two studies reported a significant TIL response in the resected specimens after administering cimetidine, while one RCT showed an escalation of CD3, CD4 and CD57 lymphocytes in peripheral blood compared to the baseline following cimetidine treatment (p < 0.01). Of the three trials that examined the effects of cimetidine on survival, only two studies revealed significant survival benefit while the remaining study only showed a trend towards survival benefit.

CONCLUSION

Repurposing of existing drugs like cimetidine has a potential to offer a survival benefit by acting as an immunomodulatory agent in patients undergoing curative resection for CRC. However, the heterogeneity seen in current studies and the evolvement of adjunctive therapies for CRC warrant large-scale, well-designed prospective RCTs to establish the efficacy of cimetidine in CRC.

Polymicrobial Sepsis Impairs Antigen-Specific Memory CD4 T Cell-Mediated Immunity

Patients who survive sepsis display prolonged immune dysfunction and heightened risk of secondary infection. CD4 T cells support a variety of cells required for protective immunity, and perturbations to the CD4 T cell compartment can decrease overall immune system fitness. Using the cecal ligation and puncture (CLP) mouse model of sepsis, we investigated the impact of sepsis on endogenous Ag-specific memory CD4 T cells generated in C57BL/6 (B6) mice infected with attenuated Listeria monocytogenes (Lm) expressing the I-A^b-restricted 2W1S epitope (Lm-2W). The number of 2W1S-specific memory CD4 T cells was significantly reduced on day 2 after sepsis induction, but recovered by day 14. In contrast to the transient numerical change, the 2W1S-specific memory CD4 T cells displayed prolonged functional impairment after sepsis, evidenced by a reduced recall response (proliferation and effector cytokine production) after restimulation with cognate Ag. To define the extent to which the observed functional impairments in the memory CD4 T cells impacts protection to secondary infection, B6 mice were infected with attenuated Salmonella enterica-2W (Se-2W) 30 days before sham or CLP surgery, and then challenged with virulent Se-2W after surgery. Pathogen burden was significantly higher in the CLP-treated mice compared to shams. Similar reductions in functional capacity and protection were noted for the endogenous OVA₃₂₃-specific memory CD4 T cell population in sepsis survivors upon Lm-OVA challenge. Our data collectively show CLP-induced sepsis alters the number and function of Ag-specific memory CD4 T cells, which contributes (in part) to the characteristic long-lasting immunoparalysis seen after sepsis.

Lessons from Hippocrates: Time to Change the Cancer Paradigm

The ultimate goal of all medical activity is to restore patients to a state of complete physical, mental, and social wellbeing. In cancer, it is assumed that this can only be obtained through the complete eradication of the tumor burden. So far, this strategy has led to a substantial improvement in cancer survival rates. Despite this, more than 9 million people die from cancer every year. Therefore, we need to accept that our current cancer treatment paradigm is obsolete and must be changed. The new paradigm should reflect that cancer is a systemic disease, which affects an individual patient living in a particular social reality, rather than an invading organism or a mere cluster of mutated cells that need to be eradicated. This Hippocratic holistic view will ultimately lead to an improvement in health and wellbeing in cancer patients. They deserve nothing less.

Perioperative changes in lymphocyte subpopulations in patients undergoing surgery for colorectal cancer

Surgical procedure has immense impact on the immune balance. However, little is known about perioperative changes in T regulatory and Th17 lymphocyte subpopulations in patients undergoing colorectal resection. Patients with resectable colon cancer were enrolled in the study. Blood samples were obtained on two occasions, i.e. before the procedure and two days after the surgery. We also recruited a control group of young, healthy individuals. Lymphocyte subpopulations were analyzed with the use of flow cytometry. Investigated subpopulations consisted of total lymphocyte count, CD4+, CD8+, T regulatory Foxp3+ (Tregs), Th17 lymphocytes and white blood cell (WBC) count. There were significant differences in immune cell levels before and after the surgery. Reduction was recorded in the CD4+, CD8+, Tregs and total lymphocyte counts (p=0.002, p=0.01, p=0.008 and p=0.001, respectively). Increase was observed in total WBC and Th17 cells, however, Th17 lymphocytes did not reach statistical significance (p=0.01 and p=0.5, respectively). In conclusion, surgical intervention caused changes in all lymphocyte subpopulations investigated in patients undergoing surgery for colorectal cancer. However, it seemed to be an effect of perioperative trauma. Further studies are needed to investigate the impact of surgical intervention on lymphocyte subpopulations.

The Effect of Perioperative Cimetidine Administration on Time to Colorectal Cancer Recurrence

BACKGROUND

Studies have reported that the perioperative use of cimetidine, a histamine type 2 receptor antagonist, in addition to chemotherapy in patients with lymph node-positive colorectal cancer (CRC) improves the survival.

STUDY QUESTION

To determine if time to CRC recurrence could be prolonged with cimetidine.

STUDY DESIGN

Cimetidine was prescribed to American Joint on Cancer Committee (AJCC) stage III CRC patients perioperatively. Tumor recurrence was defined as the time (in days) between tumor resection and CRC recurrence. Medical charts of patients diagnosed with CRC between 1996 and 2006 were reviewed. Inclusion criteria were patients with (a) AJCC stage III CRC, (b) who had undergone surgical resection of the tumor, and (c) who received chemotherapy (5-fluorouracil).

MEASURES AND OUTCOMES

AJCC stage III CRC patients who did and did not receive cimetidine as part of the treatment regimen were compared with respect to their clinical outcomes using univariate analysis and Kaplan-Meier modeling.

RESULTS

Between 1996 and 2006, 38 patients met our inclusion criteria. Twenty-six percent (10/38) received perioperative cimetidine (mean daily dose, 750 mg; mean duration, 369 days; mean total cumulative cimetidine dose, 274,070 mg/d) in addition to chemotherapy. Time to recurrence and cancer deaths were prolonged in the chemotherapy plus cimetidine group compared with the group that received chemotherapy alone (mean ± SD: 1078 ± 290 vs. 446 ± 62; P = 0.03). In addition, we found a significant positive relationship between the duration of cimetidine therapy (days) and survival duration (correlation coefficient = 0.94, P = 0.02) and time until cancer recurrence (correlation coefficient = 0.99, P = 0.04). Moreover, there was a significant positive relationship between the total cumulative cimetidine dose and survival duration (correlation coefficient = 0.92, P = 0.03).

CONCLUSIONS

Prolonged duration of cimetidine may be superior to shorter courses in prolonging recurrence of CRC and thus survival.

Exercise and Immune Function in Children

Exercise immunology is one of the fastest growing disciplines of the past 2 decades. Unfortunately, the number of investigations devoted to the pediatric population remains low, and our understanding of the interaction between acute and chronic exercise and the immune system in youth is relatively deficient. In general, healthy children experience smaller overall perturbations to the immune system in response to an acute bout of exercise as compared with adults, and they demonstrate a faster recovery of the immune system following exercise. There is only limited evidence to suggest that moderate to high levels of habitual physical activity are associated with a reduction in the incidence of infection and illness in youth. Special consideration should be made for the young athlete training and competing during an illness or infection. Some of the unique exercise responses of the immune system in children may have important clinical relevance, but much more work is required in this area.

Clinical recovery from surgery correlates with single-cell immune signatures

Delayed recovery from surgery causes personal suffering and substantial societal and economic costs. Whether immune mechanisms determine recovery after surgical trauma remains ill-defined. Single-cell mass cytometry was applied to serial whole-blood samples from 32 patients undergoing hip replacement to comprehensively characterize the phenotypic and functional immune response to surgical trauma. The simultaneous analysis of 14,000 phosphorylation events in precisely phenotyped immune cell subsets revealed uniform signaling responses among patients, demarcating a surgical immune signature. When regressed against clinical parameters of surgical recovery, including functional impairment and pain, strong correlations were found with STAT3 (signal transducer and activator of transcription), CREB (adenosine 3',5'-monophosphate response element-binding protein), and NF-κB (nuclear factor κB) signaling responses in subsets of CD14(+) monocytes (R = 0.7 to 0.8, false discovery rate <0.01). These sentinel results demonstrate the capacity of mass cytometry to survey the human immune system in a relevant clinical context. The mechanistically derived immune correlates point to diagnostic signatures, and potential therapeutic targets, that could postoperatively improve patient recovery.

Impact of sepsis on CD4 T cell immunity

Sepsis remains the primary cause of death from infection in hospital patients, despite improvements in antibiotics and intensive-care practices. Patients who survive severe sepsis can display suppressed immune function, often manifested as an increased susceptibility to (and mortality from) nosocomial infections. Not only is there a significant reduction in the number of various immune cell populations during sepsis, but there is also decreased function in the remaining lymphocytes. Within the immune system, CD4 T cells are important players in the proper development of numerous cellular and humoral immune responses. Despite sufficient clinical evidence of CD4 T cell loss in septic patients of all ages, the impact of sepsis on CD4 T cell responses is not well understood. Recent findings suggest that CD4 T cell impairment is a multipronged problem that results from initial sepsis-induced cell loss. However, the subsequent lymphopenia-induced numerical recovery of the CD4 T cell compartment leads to intrinsic alterations in phenotype and effector function, reduced repertoire diversity, changes in the composition of naive antigen-specific CD4 T cell pools, and changes in the representation of different CD4 T cell subpopulations (e.g., increases in Treg frequency). This review focuses on sepsis-induced alterations within the CD4 T cell compartment that influence the ability of the immune system to control secondary heterologous infections. The understanding of how sepsis affects CD4 T cells through their numerical loss and recovery, as well as function, is important in the development of future treatments designed to restore CD4 T cells to their presepsis state.

T-cell-mediated immunity and the role of TRAIL in sepsis-induced immunosuppression

Sepsis is the leading cause of death in most intensive care units, and the death of septic patients usually does not result from the initial septic event but rather from subsequent nosocomial infections. Patients who survive severe sepsis often display severely compromised immune function. Not only is there significant apoptosis of lymphoid and myeloid cells that depletes critical components of the immune system during sepsis, there is also decreased function of the remaining immune cells. Studies of animals and humans suggest the immune defects that occur during sepsis may be critical to pathogenesis and subsequent mortality. This review focuses on sepsis-induced alterations with the cluster differentiation (CD) 8 T-cell compartment that can affect the control of secondary heterologous infections. Understanding how a septic event directly influences CD8 T-cell populations through apoptotic death and homeostatic proliferation and indirectly by immune-mediated suppression will provide valuable starting points for developing new treatment options.

Immunologic and oncologic implications of laparoscopic surgery: what is the latest?

Laparoscopic surgery has been associated with many short-term benefits such as a shorter time to recovery, return of bowel function, less pain, and a decrease in wound infection rate. Several animal and human experiments have demonstrated an immunologic and oncologic benefit of minimally invasive surgery. Whether these results will translate into similar results in human settings is unclear. Although the first published prospective randomized clinical trial suggests better long-term outcomes for patients undergoing laparoscopic surgery, results from other ongoing randomized, controlled clinical trials are needed to verify this controversial result.

Psychological factors in immunomodulation induced by cancer surgery: a review

The immune system's efficacy in detecting and destroying cancer cells varies considerably throughout the stages of cancer development and its role may be critical particularly during the surgical period. Although surgery causes tumor cells to shed into the blood, immune cells have the capacity to destroy these tumor cells. However, surgery also suppresses cytotoxic capacity. It is particularly during this surgical period that psychological factors can have a significant dampening or strengthening impact on surgery-related immunomodulation response, thus exerting an effect on survival. This review describes the immune changes during the peri-surgical period and the influences psychological factors have on immune function, including the immune effects caused by psychological interventions in cancer patients. We recommend that future studies exploring the role of psychological factors on immune function and survival focus more on their influence during the peri-surgical period.

A meta-analysis of laparoscopy compared with open colorectal resection for colorectal cancer

The aim of this study was to compare the outcome of the overall complication, mortality, and recurrence rate between laparoscopic resection and open surgery for colorectal cancer. We searched the Medline, Embase, and Cochrane Library and systematically reviewed the randomized controlled trials by comparing the overall complication, mortality, and recurrence rate between laparoscopic resection and open surgery for colorectal cancer. Fifteen trials with 4,207 patients who reported long-term outcomes of the overall complication, mortality, and recurrence rate were included. The combined results of the individual trials showed no statistically significant difference in the odds ratio (OR) for overall recurrence (OR 0.92, 95% CI, 0.77-1.11, P=0.34), local recurrence (OR 0.81, 95% CI, 0.59-1.12, P=0.20), distant metastasis (OR 1.01, 95% CI, 0.78-1.30, P=0.95), wound-site recurrence (OR 1.97, 95% CI, 0.77-5.02, P=0.16), colorectal cancer-related mortality (OR 0.82, 95% CI, 0.66-1.02, P=0.07), colon cancer-related mortality (OR 0.85, 95% CI, 0.66-1.09, P=0.20), rectal cancer-related mortality (OR 0.76, 95% CI, 0.53-1.11, P=0.16), and overall mortality (OR 0.87, 95% CI, 0.73-1.73, P=0.11) between the laparoscopic surgery and open surgery groups. The overall complications in the laparoscopic surgery group were much lower than that in the open surgery group (OR 0.71, 95% CI, 0.58-0.87, P=0.001). This meta-analysis showed that the successful laparoscopic colorectal resection for colorectal cancer was as effective as open surgery in terms of the oncological outcomes, thereby suggesting that laparoscopic surgery can be continued in patients with colorectal cancer.

Opioid-induced immunosuppression

PURPOSE OF REVIEW

This review provides an overview of the immunological effects of commonly used analgesic opioid drugs with particular emphasis on human studies, with the final aim to highlight their potential clinical relevance.

RECENT FINDINGS

The immunomodulatory effects of morphine have been characterized in animal and human studies. Morphine decreases the effectiveness of several functions of both natural and acquired immunity, interfering with important intracellular pathways involved in immune regulation. Mainly from animal studies, however, it has emerged that not all opioids induce the same immunosuppressive effects and evaluating each opioid's profile is important for appropriate analgesic selection. The potent opioid fentanyl also exerts a relevant immunosuppression, while the partial agonist buprenorphine appears to have a more favourable immune profile. The impact of the opioid-mediated immune effects could be particularly dangerous in selective vulnerable populations, such as the elderly or immunocompromised patients.

SUMMARY

The impact of opioid drug treatment on immunity may be a new safety concern for the physician. Although many advances have been made in understanding the effects of opioid drugs on immune responses, their relevance is not completely clear. The scientific community must be aware that it is about time to perform well designed clinical studies in order to assess the importance of opioid-induced immune suppression.

Buprenorphine ameliorates the effect of surgery on hypothalamus-pituitary-adrenal axis, natural killer cell activity and metastatic colonization in rats in comparison with morphine or fentanyl treatment

Not all opioids employed in clinical practice share the same immunosuppressive properties. The potent partial micro-agonist buprenorphine appears to exhibit a neutral effect on the immune responses. Surgery stress is associated with decreased natural killer cell activity (NK) and enhancement of tumor metastasis in rats. We analyzed the ability of buprenorphine to prevent the effects of experimental surgery on HPA activation (plasma corticosterone levels), NK activity and lung diffusion of the NK sensitive tumor MADB106. Buprenorphine (0.1mg/kg) was compared with equianalgesic doses of fentanyl (0.1mg/kg) and morphine (10mg/kg) in this animal model. In normal animals morphine and fentanyl stimulate the HPA axis, decrease NK activity and augment tumor metastasis, while buprenorphine is devoid of these effects. Surgery significantly raised corticosterone levels, suppressed NK activity and increased MADB106 metastasis. Only buprenorphine was able to prevent the neuroendocrine and immune system alterations and ameliorate the increase of tumor metastasis induced by surgical stress. These preclinical findings suggest that an adequate treatment of surgically induced stress immunosuppression with an opioid drug devoid of immunosuppressive effects may also play a protective role against the metastatic diffusion following cancer surgery.

Host antitumour immune responses to HIFU ablation

The ideal cancer therapy not only induces the death of all localized tumour cells without damage to surrounding normal tissue, but also activates a systemic antitumour immunity. High-intensity focused ultrasound (HIFU) has the potential to be such a treatment, as it can non-invasively ablate a targeted tumour below the skin surface, and may subsequently augment host antitumour immunity. In addition to thermal and cavitation effects, which act directly and locally on the tumour, there is increasing evidence linking systemic anti-tumour immune response to HIFU ablation. This may provide micro-metastatic control and long-term tumour resistance for cancer patients. The goal of this article is to review the emerging pre-clinical and clinical results suggesting that HIFU ablation may enhance host anti-tumour immunity, and to discuss its potential mechanisms. It is concluded that the systemic immune response induced by thermal ablation may play an important role in local recurrence and metastasis control after HIFU treatment.

Microarray analysis of the differential effects of open and laparoscopic surgery on murine splenic T-cells

BACKGROUND

Surgical trauma depresses cell-mediated immunity of a duration and magnitude proportional to the degree of injury. However, the cellular mechanism underlying this effect is poorly understood. Microarrays were used to survey gene expression in murine splenic T-cells after pneumoperitoneum and laparotomy.

METHODS

C3H/HeJ mice were assigned randomly to undergo anesthesia alone, sham laparotomy, or CO(2) pneumoperitoneum and sacrificed 12 or 24 hours later. RNA was isolated from purified splenic T-cells and hybridized to Affymetrix oligonucleotide microarrays.

RESULTS

Relative to anesthesia, 116 genes after pneumoperitoneum and 398 genes after laparotomy showed a > or =2-fold change in expression at 12 hours. One hundred thirty-two genes after pneumoperitoneum and 157 genes after laparotomy met those criteria at 24 hours. Comparing surgical modalities, 177 genes were increased and 15 decreased > or =2-fold after laparotomy relative to pneumoperitoneum at 12 hours, compared with 44 and 5 genes respectively at 24 hours. Expression changes for 8 genes were validated by quantitative real-time polymerase chain reaction.

CONCLUSIONS

Laparotomy and pneumoperitoneum alter splenic T-cell gene expression, with the most extensive changes occurring 12 hours after laparotomy. This study is one of the first comprehensive genomic studies of the molecular effects of surgical manipulation on immune function. The genes identified are potential targets for modulating the immune response to surgery.

Small Cell Undifferentiated Carcinoma of the Ascending Colon with Rapid Enlargement after Resection: Report of a Case and Review of the Literature

Although adenocarcinoma represents the vast majority of neoplasms of the large intestine, small cell undifferentiated carcinoma (SCUC) also arises from the colorectum. SCUC of the colorectum is highly malignant and shares the similarities in histologic characteristics, behavior, and histochemistry with SCUC of the lung. We report herein a case of SCUC in the ascending colon with rapid enlargement after resection. A 70-year-old male, who presented to a nearby physician with chief complaints of pain in the right lower quadrant, was referred to our hospital. We found a tumor mass that was approximately 15 cm in size in the right lower quadrant. Computed tomography (CT) images showed an irregularly shaped tumor, located inferior to the lower border of the right kidney and in the area of the ascending colon. By colonoscopy, we found a circumferential tumor of the ascending colon. A biopsy indicated it to be SCUC. The patient underwent right hemicolectomy. Two weeks after the resection, we palpated a tumor mass in the same area. The abdominal CT images showed a tumor mass that was approximately 10 cm in size. The tumor rapidly enlarged, and the patient died of multiple organ failure. SCUC is a tumor with a high malignant potential. Radical treatment cannot be achieved by surgical therapy alone and hence further studies of effective adjuvant therapy would be required.

Thoracotomy is associated with significantly more profound suppression in lymphocytes and natural killer cells than video-assisted thoracic surgery following major lung resections for cancer

Major surgery is immunosuppressive, and this could have an impact on postoperative tumor immunosurveillance and, therefore, long-term survival in cancer patients. Video-assisted thoracic surgery (VATS) lung resection is a new alternative surgical approach to thoracotomy for patients with early lung cancer. This is a pilot study to examine the postoperative changes in leukocytes, lymphocyte subsets, B cells, T cells, and natural killer (NK) cells in non-small-cell lung cancer (NSCLC) patients undergoing lung resection with VATS versus thoracotomy approaches. Twenty-one consecutive patients with resectable primary NSCLC were assigned to VATS or thoracotomy approach over a 3-month period. Blood samples were collected preoperatively and at postoperative days (POD) 1, 3, and 7 for flow cytometry determination of total leucocytes, B cells, NK cells, lymphocytes, total T cells, and T4 and T8 cell numbers. There were no demographic differences between the two groups. Compared with the preoperative values, significantly increased total white cell numbers were detected at POD 1, 3, and 7 in all patients. At POD 1, although T8 cells and NK cells were reduced in both groups, total T cell, T4 cell, and lymphocyte numbers were significantly reduced only in the thoracotomy group. At POD 7, NK cell numbers were significantly lower in the thoracotomy group than that in the VATS group. No significant intra- or intergroup differences were seen with B cells. No significant differences in survival or disease-free survival were found between the two groups. Thus, VATS major lung resection for NSCLC is associated with less, as well as quicker recovery from, postoperative immunosuppression compared with the thoracotomy approach. The clinical relevance of better preserved cellular immunity in the early postoperative period warrants confirmation from large randomized trials.

Technique and survival after laparoscopically assisted right hemicolectomy

BACKGROUND

The role of laparoscopic colon resection in the management of colon cancer is still controversial. In this article, the surgical strategy and techniques are described, with further consideration of the oncologically relevant aspects.

METHODS

Between March 1993 and July 2003, we performed laparoscopic right hemicolectomy in 56 patients with right colon carcinoma. Average age was 74.5 years (range, 17-92). We performed a standardized surgical procedure that included mobilization from the vascularized mesenteric bridges with a window technique, transection of the ileocolic lymphovascular pedicle, and lateral and proximal mobilization of the ileocecum, ascending colon, right flexure, and proximale transversum. After enlargement of one of the trocar incisions the exteriorized colon was resected and an extracorporeal anastomosis was performed in the standard manner.

RESULTS

There were no conversions to open. The mean operating time was 119 +/- 38 min, the mean length of resected colon was 27.8 +/- 4.48 cm, and the average width of the clear margins was 6.8 +/- 5.3 cm. One patient died. Lymph nodes were positive in 21 patients. The 5-year survival rate in the 48 patients who were operated on with curative intent was 75%. We have had two local recurrences. The overall 5-year mortality-free fraction was 63%. Cox multivariate analysis showed that the mortality-prognostic factors were tumor stage and length of resected colon, whereas Kaplan-Meier analysis showed that the mortality-prognostic factors were positive lymph nodes and tumor stage.

CONCLUSIONS

Our results show that laparoscopic right hemicolectomy for colon cancer can be performed safely. Complications and recurrence rates are comparable to those for left-sided laparoscopic and open procedures. Therefore, we recommend this procedure as the method of choice. Laparoscopically treated patients with stage II and stage III disease have almost the same cumulative rate of survival.

Immunological advantages of advanced laparoscopy

Surgical trauma causes significant alterations in host immune function. Compared with open surgery, laparoscopic surgery is associated with reduced postoperative pain and more rapid return to normal activity. Experimental data have also shown more aggressive tumor establishment and growth rates following open surgery and laparoscopic surgery. Surgery-related immunosuppression may be partly responsible for the differences in cancer growth and outcome noted. It is clear that the choice of abdominal surgical approach has immunologic consequences. Further studies are needed to better the time course and extent of surgery-related alterations in the immune system and their clinical importance. A better understanding of the impact of surgery on the immune system may provide opportunities for pharmacologic manipulation of postoperative immune function to improve clinical results.

The Physiologic Effects of Laparoscopy

The use of laparoscopic approaches to surgical disease continues to advance quickly. Laparoscopy applied to oncologic surgery continues to be debated. We review the experience of laparoscopy as it relates to surgery for tumors. Specifically, we discuss the physiologic changes and tumor response to laparoscopy, as well as the current concepts explaining port site recurrence.

Role and limitations of laparoscopic liver resection of colorectal metastases

BACKGROUND

The current experience of laparoscopic liver resection is reviewed focusing on the role and limitations of resection of colorectal metastases. Surgical technique, outcome, and the main controversies regarding the procedures are described.

METHODS

Current literature on laparoscopic liver resection is reviewed based on reports identified following a specified PubMed search.

RESULTS

Available evidence indicates that laparoscopic liver resection can be made safely in selected patients with comparable duration of surgery, blood loss, tumour clearance, and mortality to that of open resection. Tumours localised peripherally in the left lateral segments of the liver or in segments IV-VI seem to be best suited for laparoscopic resection. The laparoscopic approach may be beneficial to the patients as compared to conventional resection but randomised trials are pending. Laparoscopic resection of colorectal liver metastases is described in a small number of patients only. The long-term outcome following such resections is not adequately documented.

CONCLUSIONS

Laparoscopic liver resection is a promising technique with a comparable short-term outcome to that of open procedures but with the potential advantages of minimal invasive treatment. The technique should be further evaluated in properly designed trials. Laparoscopic resection of colorectal liver metastases should not be performed on a regular basis until long-term results are defined.

Activated anti-tumor immunity in cancer patients after high intensity focused ultrasound ablation

T cell-mediated immune responses represent the main cellular antitumor immunity in cancer patients. Recent studies have shown that that both surgical procedure and radiation therapy could cause the functional suppression of lymphocyte-mediated cellular immunity. The purpose of current study is to evaluate whether high intensity focused ultrasound (HIFU) might change a systemic antitumor immunity, particularly T lymphocyte-mediated immunity in cancer patients. A total of 16 patients with solid malignancies were treated with HIFU. Among them, six patients had osteosarcoma (Enneking stage, II(B)4, III(B) 2), five had hepatocellular carcinoma (TNM stage, III 3, IV 2), and five had renal cell carcinoma (TNM stage, III 2, IV 3). Using flow cytometry technique, T lymphocyte and subset, B lymphocyte and natural killer cell (NK) in the peripheral blood were measured in these patients on the day before HIFU and 7 to 10 d after HIFU. The statistical significance of any observed difference is evaluated by Student's t-test. The results showed a significance increase in the population of CD4(+) lymphocytes (p < 0.01) and the ratio of CD4(+) /CD8(+) (p < 0.05) in the circulation of cancer patients after HIFU treatment. The abnormal levels of CD3(+) lymphocytes returned toward the normal range in two patients, CD4(+)/CD8(+) ratio in 3, CD19(+) lymphocytes in one and cytotoxic NK in one, respectively, in comparison to control values. It is concluded that HIFU could enhance a systemic antitumor cellular immunity in addition to local tumor destruction in patients with solid malignancies.

Current status of laparoscopic resection for colorectal cancer

GOALS

To define the current role of laparoscopic resection for colorectal cancer.

BACKGROUND

Perhaps in no other field has so much controversy been generated by laparoscopy as in its application to curative resection of cancer of the colon and rectum. The main controversy centers around the oncologic outcomes of laparoscopic resections. The 3 major issues are: the adequacy of oncologic resection, recurrence rates and patterns, and the long-term survival.

STUDY

A review of published data by search of Medline database with focus on clinical studies.

RESULTS

Laparoscopic colectomy is feasible and safe. Modest benefits in the quality of life are observed. Same oncologic resection can be performed laparoscopically with no adverse influence on the recurrence rates. In particular, wound recurrences are not a specific complication of laparoscopic technique. At least equivalent survival is obtained by laparoscopic colectomy.

CONCLUSIONS

Laparoscopy does not seem to adversely affect chance of cure of colorectal cancer.

Perioperative cimetidine administration promotes peripheral blood lymphocytes and tumor infiltrating lymphocytes in patients with gastrointestinal cancer: Results of a randomized controlled clinical trial

AIM: To study the effects of perioperative administration of cimetidine (CIM) on peripheral blood lymphocytes, natural killer (NK) cells and tumor infiltrating lymphocytes (TIL) in patients with gastrointestinal (GI) cancer.

METHODS: Forty-nine GI cancer patients were randomized into treatment group, who took CIM in perioperative period, and control group, who did not take the drug. The treatment was initiated 7 days before operation and continued for 10 days after surgery. At baseline examination before operation, on the 2nd and 10th postoperative days, total T lymphocytes, T helper cells, T suppressor cells, and NK cells in peripheral blood were measured respectively by immunocytochemical method using mouse-anti human CD₃, CD₄, CD₈ and CD₅₇ monoclonal antibodies. Blood samples from 20 healthy volunteers were treated in the same way as normal controls. Surgical specimens were examined during routine histopathological evaluation for the presence of TIL in tumor margin. Immunohistochemical study was performed to measure the proportion of T and B lymphocytes in TIL population. T and B lymphocytes were detected respectively using mouse-anti-human CD₃ and CD₂₀ monoclonal antibodies.

RESULTS: In comparison with normal controls, both the treatment and control groups had decreased T cells, T helper cells and NK cells at baseline. In control group, total T cells, T helper cells and NK cells declined continuously with the disease progression and the decrease became more obvious after operation. From baseline to the 2nd postoperative day, the proportion of total T cells, T helper cells, and NK cells went down from 60.5 ± 4.6% to 56.2 ± 3.8%, 33.4 ± 3.7% to 28.1 ± 3.4%, and 15.0 ± 2.8% to 14.2 ± 2.2%, respectively. On the other hand, there were significant improvements in these parameters after CIM treatment. On the 10th postoperative day, the treatment group had significantly higher percentages of total T cells, T helper cells and NK cells than control group. Moreover, CIM treatment also boosted TIL response, as was reflected by findings that 68%(17/25) of the patients in treatment group had significant TIL responses and only 25% (6/24) of the cases had discernible TIL responses (P < 0.01).

CONCLUSION: Perioperative application of CIM to GI cancer patients could help restore the diminished cellular immunity induced by tumor burden and surgical maneuver. The drug could also boost TIL responses to tumor. These effects suggest that the drug be used as an immunomodulator for GI cancer patients.

Laparoscopic-assisted cecectomy is associated with decreased formation of postoperative pulmonary metastases compared with open cecectomy in a murine model

BACKGROUND

It was shown in a murine model that sham laparotomy is associated with a higher incidence of postoperative lung metastases when compared with results seen after carbon dioxide pneumoperitoneum. Using the same tumor model, the present study was undertaken to determine if the addition of bowel resection to the operative procedure would impact the results.

METHODS

Sixty mice underwent anesthesia alone (anesthesia control [AC]), laparoscopic-assisted cecectomy (LC), or open cecectomy (OC). After surgery, all animals received tail vein injections of 105 TA3-Ha tumor cells. On postoperative day 14, the lungs and trachea were excised en bloc and processed, and surface lung metastases were counted and recorded by a blinded observer.

RESULTS

The mean number of surface lung metastases in the AC, LC, and OC groups was 30.9, 76.3, and 134.5, respectively. Significantly more metastases were documented after OC (P<.001) and LC (P<.05) than after anesthesia alone. Mice in the LC group had significantly fewer lung metastases (43% less) than mice in the OC group (P<.01).

CONCLUSIONS

OC was associated with significantly more lung metastases than either LC or AC. Surgery-related immune suppression or trophic tumor cell stimulation occurring after surgery may contribute to this phenomenon.

Role of HER2 in wound-induced breast carcinoma proliferation

OBJECTIVE

Clinical and experimental data have suggested that surgical removal of primary tumours promotes the growth of metastatic lesions. We assessed the effect of surgery on proliferation of breast carcinomas, in particular those overexpressing HER2 oncoprotein.

METHODS

Proliferation of breast carcinoma cells was assessed by MIB-1 immunohistochemistry in sections of primary breast carcinomas and in residual tumour found in re-excision specimens, and in in-vitro cell lines by colorimetric assay. Epidermal growth factor (EGF)-like growth factors were measured by displacement of radiolabelled EGF from its receptor. Cellular damage was measured in terms of creatine phosphokinase level. Downmodulation of HER2 was investigated by cytoplasmic expression of anti-HER2 antibody and by inhibition with anti-HER2 antibody trastuzumab.

FINDINGS

Residual breast carcinomas that had been surgically removed within 48 days after first surgery showed a significant increase in proliferation if they were HER2-positive. Wound drainage fluid and postsurgical serum samples from patients stimulated in-vitro growth of HER2-overexpressing breast carcinoma cells. Removal of HER2 from the cell membrane led to a striking reduction of the induced proliferation. The amount of EGF-like growth factors in post-surgical serum samples, as well as the extent of drainage-fluid-induced proliferation, directly correlated with the amount of surgical damage assessed by creatine phosphokinase levels (r=0.77, p=0.002 and r=0.69, p=0.009, respectively). Treatment of HER2-positive tumour cells with trastuzumab before adding the growth stimulus abolished drainage-fluid-induced proliferation.

INTERPRETATION

HER2 overexpression by breast carcinoma cells has a role in postsurgery stimulation of growth of breast carcinoma cells.

Long-term monitoring of cell-mediated immunity in disease-free breast cancer patients: a preliminary retrospective study

In 102 N- and 44 N+ disease-free breast cancer patients, lymphocytic populations and skin reaction of delayed hypersensitivity (SRDH) were monitored up to 266 months after mastectomy to find out whether they were similar or different from control values. In two selected groups of 34 N- and 11 N+ breast cancer patients, the whole 10 year follow-up was divided into three subintervals, each of them lasting 40 months and the time course of lymphocytic populations was evaluated. In the 102 N- patients, mean CD4+, CD8+, CD3+ values were lower (P < 0.01, P < 0.001, P < 0.01, respectively) while CD4+/CD8+ ratio was higher (P < 0.05) than in controls. Fifteen N- breast cancer patients (16%) were anergic compared to 30(32%) of controls (P < 0.05). In the 34 selected N- breast cancer patients soon after mastectomy the mean value of CD4+, CD8+, CD3+ T subpopulations was lower (P < 0.01, P < 0.001, P < 0.01, respectively) than in controls. Successively their mean value increased so that in the last subinterval they were not or were only slightly lower (P n.s., P < 0.05, P < 0.05, respectively) than in controls. In the 44 N+ patients, mean CD4+, CD8+, CD3+ values were lower (P < 0.001, v < 0.05, P < 0.01, respectively) and CD19+ lymphocytes higher (P < 0.001) than in controls. Five N+ breast cancer patients (13%) were anergic compared to 32% of controls (P < 0.05). In the 11 selected N+ breast cancer patients soon after mastectomy, the mean value of CD4+, CD8+ T subpopulations and CD16+56+ cells was significantly lower (P < 0.001, P < 0.001, P < 0.01, respectively) than in controls. Successively their mean value constantly increased so that in the last subinterval, no or slight (P n.s., P < 0.05, P n.s., respectively) significant difference compared to controls occurred. The mean CD4+/CD8+ ratio value of N- patients was significantly higher than in controls. However in the last subinterval, the significance was lower than in the first one (P < 0.05 and P < 0.01, respectively). In the N+ patients, the mean value of CD4+/CD8+ ratio was constant, although not significantly, lower than in controls; however it progressively increased from the first to the last subinterval. Therefore the significance of the difference of the mean CD4+/CD8+ ratio between N- and N+ patients strongly decreased from the first to the last subinterval (P < 0.001 and P < 0.05, respectively). These data indicate that in breast cancer patients, following mastectomy, a significant activation of memory and CD4+ T cells and long-term decrease of the circulating immunocompetent CD4+, CD8+ and CD16+56+ cells occurs. The prolonged disease-free interval observed in the 34 N- and 11 N+ breast cancer patients can be correlated with the restoration of the normal state of cell-mediated immunity.

The analgesic drug tramadol prevents the effect of surgery on natural killer cell activity and metastatic colonization in rats

Surgery stress has been shown to be associated in rat with decreased natural killer (NK) cell activity and enhancement of tumor metastasis. We have previously shown that the analgesic drug tramadol stimulates NK activity both in the rodent and in the human. In the present study, we analyze, in the rat, tramadol ability to prevent the effect of experimental surgery on NK activity and on the enhancement of metastatic diffusion to the lung of the NK sensitive tumor model MADB106. The administration of tramadol (20 and 40 mg/kg) before and after laparatomy significantly blocked the enhancement of lung metastasis induced by surgery. In contrast, the administration of 10 mg/kg of morphine was not able to modify this enhancement. The modulation of NK activity seemed to play a central role in the effect of tramadol on MADB106 cells. In fact, both doses of tramadol were able to prevent surgery-induced NK activity suppression, while the drug significantly increased NK activity in normal non-operated animals. Morphine, that in normal rats significantly decreased NK cytotoxicity, did not prevent surgery-induced immunosuppression. The good analgesic efficacy of tramadol combined with its intrinsic immunostimulatory properties suggests that this analgesic drug can be particularly indicated in the control of peri-operative pain in cancer patients.

Laparoscopy-assisted colectomy versus open colectomy for treatment of non-metastatic colon cancer: a randomised trial

BACKGROUND

Although early reports on laparoscopy-assisted colectomy (LAC) in patients with colon cancer suggested that it reduces perioperative morbidity, its influence on long-term results is unknown. Our study aimed to compare efficacy of LAC and open colectomy (OC) for treatment of non-metastatic colon cancer in terms of tumour recurrence and survival.

METHODS

From November, 1993, to July, 1998, all patients with adenocarcinoma of the colon were assessed for entry in this randomised trial. Adjuvant therapy and postoperative follow-up were the same in both groups. The main endpoint was cancer-related survival. Data were analysed according to the intention-to-treat principle.

FINDINGS

219 patients took part in the study (111 LAC group, 108 OC group). Patients in the LAC group recovered faster than those in the OC group, with shorter peristalsis-detection (p=0.001) and oral-intake times (p=0.001), and shorter hospital stays (p=0.005). Morbidity was lower in the LAC group (p=0.001), although LAC did not influence perioperative mortality. Probability of cancer-related survival was higher in the LAC group (p=0.02). The Cox model showed that LAC was independently associated with reduced risk of tumour relapse (hazard ratio 0.39, 95% CI 0.19-0.82), death from any cause (0.48, 0.23-1.01), and death from a cancer-related cause (0.38, 0.16-0.91) compared with OC. This superiority of LAC was due to differences in patients with stage III tumours (p=0.04, p=0.02, and p=0.006, respectively).

INTERPRETATION

LAC is more effective than OC for treatment of colon cancer in terms of morbidity, hospital stay, tumour recurrence, and cancer-related survival.

Impact of splenectomy on the early outcome after oesophagectomy for squamous cell carcinoma of the oesophagus

AIM

Operative procedures for oesophageal malignancies are becoming more extensive and may result in fatal complications. Splenectomy compromises the immune system and can lead to increased susceptibility to infections. The aim of the present study was to report the early outcome of patients who underwent oesophagectomy and simultaneous splenectomy due to oesophageal squamous cell carcinoma (SCC).

METHODS

Pre-operative risks and post-operative morbidity and mortality in 135 patients who had undergone extensive oesophagectomy without simultaneous splenectomy for SCC of the thoracic oesophagus were compared with those of 14 patients who had undergone oesophagectomy associated with splenectomy.

RESULTS

Post-operative pneumonia, intra-abdominal abscess, post-operative sepsis and anastonotic leakage were significantly increased when splenectomy was added to the original operation. The incidence of in-hospital death was significantly higher among splenectomized than non-splenectomized patients (35.7% vs 8.1%, P<0.01). Pulmonary complications and leakage were the main causes of death. Multivariate analysis recognized splenectomy as an independent prognostic factor for in-hospital death following transthoracic oesophagectomy for SCC.

CONCLUSION

The addition of splenectomy to transthoracic oesophagectomy for oesophageal carcinoma can be a fatal combination. Preservation of the spleen should be the primary intention. In circumstances that necessitate splenectomy precautions should be taken to prevent post-operative infectious complications.

Effect of laparoscopy on immune function

BACKGROUND

Laparoscopic surgery is believed to lessen surgical trauma and so cause less disturbance of immune function. This may contribute to the rapid recovery noted after many laparoscopic operations. Preservation of both systemic and intraperitoneal immunity is particularly important in surgery for sepsis or cancer and so an understanding of the impact of laparoscopy on immune function is relevant.

METHODS

Literature on immunological changes following laparoscopy and open surgery was identified from Medline, along with cross-referencing from the reference lists of major articles on the subject.

RESULTS AND DISCUSSION

Despite a few contradictory reports, systemic immunity appears to be better preserved after laparoscopic surgery than after open surgery. However, the local intraperitoneal immune system behaves in a particular way when exposed to carbon dioxide pneumoperitoneum; suppression of intraperitoneal cell-mediated immunity has been demonstrated in a number of studies. This feature may be clinically important and should be acknowledged when considering laparoscopic surgery in patients with malignancy or sepsis.

Effect of oesophagectomy on monocyte-induced apoptosis of peripheral blood T lymphocytes

BACKGROUND

Surgical stress has been reported to induce immunosuppression. The mechanisms giving rise to T-cell dysfunction following surgery are still unclear. The cellular mechanisms behind T-cell dysfunction following surgery were investigated, based on the induction of T-cell apoptosis and downregulation of T-cell signalling molecules.

METHODS

Peripheral blood T cells were collected and separated before and after surgery in patients who had oesophagectomy, gastrectomy or cholecystectomy, and studied for their ability to produce cytokines, the induction of T-cell apoptosis with terminal deoxynucleotidyl transferase-mediated dUPT-biotin nick end labelling methods, and the expression of T-cell signalling zeta (TCR zeta) molecules with intracellular staining.

RESULTS

The increased degree of T-cell apoptosis, downregulation of TCR zeta molecules and impaired cytokine production of T cells were significant on days 1 and 3 after operation in patients who had oesophagectomy, but not after gastrectomy or cholecystectomy. A higher level of T-cell apoptosis was observed in the co-culture with postoperative monocytes than with preoperative monocytes.

CONCLUSION

Peripheral blood T cells obtained after oesophagectomy underwent apoptosis that correlated with the downregulation of TCR zeta molecules. Postoperative monocytes induced by surgical stress were able to mediate the T-cell apoptosis.

Alterations in the immune system and tumor growth in laparoscopy

BACKGROUND

The explosion in the use of therapeutic laparoscopy during the past decade has focused much research interest on finding a basic scientific support for the clinically apparent attenuation of the stress response to surgery. In particular, the potential impact that attenuation of the immune response to surgery may have on laparoscopy for the cure of malignancy has attracted much attention.

METHODS

A review of the published literature on the stress response to laparoscopic surgery and the impact of laparoscopy on tumor growth was performed.

RESULTS

Evidence favors an attenuation of the immune response to surgery with laparoscopic cholecystectomy. Whether this is true also of more major procedures such as laparoscopically assisted colectomy for malignancy is currently unclear. In animal models, tumor growth after laparoscopic surgery is less than after laparotomy and depends on the insufflation agent used.

CONCLUSIONS

Laparoscopic cholecystectomy appears to be associated with attenuation of the immune response to surgery. The implications of these findings for the future use of laparoscopic surgical techniques for malignant disease remain unclear.

Laparotomy, laparoscopy, cancer, and beyond

The fate of laparoscopic methods for the treatment of cancer remains uncertain. Published middle-range oncologic results from nonrandomized studies demonstrate that laparoscopic methods are associated with an outcome comparable with results after open resection. The world awaits the 3- and 5-year oncologic results of the ongoing randomized and prospective trials. There is a possibility that laparoscopic methods may be associated with a survival benefit. Port tumors remain a concern. However, results at this writing suggest that these recurrences take place at a frequency similar to that of incisional recurrences following open cancer resection. Port tumors currently are viewed as local recurrences. Traumatization of the tumor at the time of resection is thought to be the most important surgery-related risk factor. The demonstration of a survival benefit in a randomized trial would likely have a tremendous impact on the surgical world. Avoidance of laparotomy-related immunosuppression and tumor stimulation, both of which have been well demonstrated in animal studies, theoretically, might account for differences in cancer outcome. The early postoperative period may be a critical time during which the fate of many cancer patients is determined. It is possible that this may be an ideal time frame for antitumor immunotherapy because the tumor burden is at its lowest, and because immunotherapy, unlike conventional chemotherapy, is unlikely to have a negative impact on wound and anastomotic healing. Perioperative nonspecific upregulation of immune function via pharmacologic means may improve long-term oncologic results. Similarly, preoperative tumor vaccines might provide patients with a specific means of combating any remaining tumor cells after curative resection. The results of several recently completed murine studies support both of these ideas. Finally, early postoperative administration of monoclonal antitumor antibodies might provide patients with specific means of combating any remaining tumor cells after curative resection. The introduction of advanced minimally invasive techniques nearly a decade ago has led to new methods of approaching malignant tumors that have the potential to have an impact on the oncologic outcome of cancer patients. This decade-long journey also has led to new insights regarding the impact of surgery on the patient. It also has alerted us concerning the importance of the immediate postoperative period in the patient's ongoing struggle against the tumor. These insights hopefully will lead to better surgical methods and new perioperative adjuvant therapies that will increase the rate of survival and reduce the recurrence rates for cancer patients.

Preoperative immunosuppression: its relationship with high morbidity and mortality in patients receiving thoracic esophagectomy

The operative procedure for thoracic esophageal cancer, including thoracotomy, laparotomy, and three-field lymph node dissection, is a particularly stressful surgery that is characterized by high morbidity and mortality. The aim of this study was to evaluate the immunologic and nutritional states of patients to determine possible predictive factors of morbidity and mortality in patients receiving thoracic esophagectomy. Patients receiving thoracic esophagectomy were retrospectively divided into two groups. One group had postoperative infectious complications (group C+, n = 27), and the other had no complications (group C-, n = 76). They were treated with total parenteral nutrition or enteral nutrition providing 35-40 kcal. kg(-1). d(-1) of energy and 1.3-1.5 kcal. kg(-1). d(-1) of amino acids throughout the study period. The phytohemagglutinin (PHA)- and concanavalin A (Con A)-induced proliferation of peripheral blood mononuclear cells (PBMC) from the patients were measured before and at days 7 and 21 after the operation. Serum albumin, prealbumin, transferrin, the retinol binding protein, and the C-reactive protein were also evaluated. Three patients out of 27 in group C+ died because of severe infectious complications, whereas none of patients was fatal in group C-. PHA- and Con A-induced proliferation of PBMC was significantly low before the operation and remained suppressed on the 21st postoperative day in group C+. No significant difference was observed in nutritional status during the perioperative days between the two groups. Our results indicate that esophageal cancer patients with preoperative suppression of the cell-mediated immunity can be identified as a higher risk population in the postoperative period. When adequate nutrition is received, however, the correlation between nutritional status and mortality disappears.

Erythrocyte transfusion causes immunosuppression after total hip replacement

A prospective study of 34 patients undergoing total hip replacement was done to determine whether homologous erythrocyte transfusion causes postoperative immunosuppression. In the transfused patient group (14 patients), there was a reduction in CD3+ and CD3+4+ cell numbers at Day 2, returning to preoperative levels by Day 7. In contrast, in the untransfused patient group (20 patients), there was no significant depression in these lymphocyte subgroups at Day 2 and an increase in total lymphocyte, CD3+, CD3+4+, and CD3+4-8- cell numbers at Day 7. In both patient groups there was postoperative leukocytosis, granulocytosis, and monocytosis at Days 2 and 7, with no significant change in postoperative B (CD19+) cell numbers, natural killer cells, or the minor T cell populations of CD3+4+8+ and CD3+25+. The lymphocyte functional test of Candida recall was significantly impaired at Day 7 in the transfused patient group, where Candida recall is a memory T cell response to an antigen extracted from the yeast Candida Albicans. These findings suggest that homologous erythrocyte transfusion after hip replacement surgery causes cell mediated immune suppression. The main clinical implication of the current study is that perioperative homologous erythrocyte transfusion may place patients at greater risk of infectious complications, including infection of the prosthesis.

Influence of multimodality therapy on the cellular immunity of patients with esophageal cancer

BACKGROUND

Cancer patients have often been reported to have impaired immune function, and the effect of treatment modalities, such as surgery, irradiation, and chemotherapy, in depressing patients' immunity has also been reported. In this investigation, the effect of treatment on the cellular immunity of esophageal cancer patients was evaluated.

METHODS

Immunological parameters, such as natural killer (NK) activity and lymphocyte subsets in peripheral blood, were measured in 32 esophageal cancer patients on 5 occasions (on the day of admission, 2 days before surgery, and 1 week, 1 month, and 2 months after surgery).

RESULTS

NK activity was greatly impaired shortly after the operation, and the percentages of lymphocytes as a whole, and CD8+, CD16+, and CD57+ lymphocytes were significantly decreased, on the other hand, a postoperative increase in the CD4+/CD8+ ratio was observed. No significant depression of immune function by postoperative irradiation was observed.

CONCLUSIONS

The results of this study suggest that cellular immunity, especially cytotoxicity, shortly after esophagectomy may be greatly impaired by the surgical stress of esophagectomy and an added effect of chemotherapy.

Cell-mediated immune response is better preserved by laparoscopy than laparotomy

BACKGROUND

This study compares the effects of carbon dioxide pneumoperitoneum versus laparotomy on cellular-mediated immune response in a murine model.

METHODS

Sixty-eight female C3H/He mice were sensitized to keyhole limpet hemocyanin (KLH) and to a mouse mammary carcinoma cell line (MC2) before surgery. Animals were randomized into 4 groups: group I, anesthesia (control); group II, pneumoperitoneum with carbon dioxide; group III, extraperitoneal wound; group IV, laparotomy. All animals were challenged subsequently with KLH and MC2 tumor cells. Delayed-type hypersensitivity skin reaction (DTH) to KLH was measured on postoperative days (PODs) 1, 2, 4, and 5. Tumor growth was assessed weekly as an indicator of postoperative cellular immune response.

RESULTS

Compared with preoperative values, postoperative DTH skin reactions were significantly less for all PODs in groups III and IV (P < .05), on POD 1 and 4 in group II (P < .05) and POD 4 for group I (P < .05). Group IV showed significantly fewer DTH skin reactions for all PODs compared with groups I and II (P < .05) and all PODs except on day 2 compared with group III (P < .05). Tumor growth was significantly increased at postoperative week 2 (n = 3/17 mice) and 3 (n = 4/17 mice) in group IV, when compared with groups I and II (P < .05).

CONCLUSIONS

Cellular immunity is preserved after carbon dioxide pneumoperitoneum compared with extraperitoneal incisions and laparotomy as measured by DTH and the ability to reject an immunogenictumor.

The fermentable fiber content of the diet alters the function and composition of canine gut associated lymphoid tissue

The ingestion of plant fibers and their susceptibility to microbial fermentation in the large bowel modulate intestinal morphology but little is known about effects on the gut associated lymphoid tissue (GALT). The aim of the present study was to determine the effect of consuming diets containing different levels of fermentability fiber on immune function. Sixteen adult mongrel dogs (23 +/- 2 kg) were fed (14 days) in a randomized cross over design two isoenergetic isonitrogenous diets containing 8.3 g/kg non-fermentable or 8.7 g/kg fermentable fibers. Lymphocytes were isolated from blood prior to starting the study and at the end of each diet period. At study completion, lymphocytes were isolated from the gut associated lymphoid tissue (GALT) of the small intestine for characterization by immunofluorescence and to determine their ability to respond to mitogenic stimulation. Feeding high fermentable fibers increased (P < 0.05) the CD4/CD8 ratio and decreased (P < 0.05) the proportion of B cells in peripheral blood without changing natural killer cell activity or the response to mitogens. Mesenteric lymph node cells from dogs fed the low then high fermentable fiber diet contained a higher (P < 0.05) proportion of CD4+ cells and a higher (P < 0.05) response to mitogens. Intraepithelial, Peyer's patches and lamina propria cells contained a greater (P < 0.05) proportion of CD8+ cells when dogs were fed a low fermentable fiber diet followed by a high fermentable fiber diet. T cell mitogen responses in vitro were higher for intraepithelial but lower for Peyer's patches and lamina propria cells from dogs who were fed the low fermentable fiber diet followed by the high fermentable fiber diet (P < 0.05). In conclusion, the fermentable fiber content of the diet had very little effect on the type and function of immune cells in peripheral blood. However, feeding dogs a high fermentable fiber diet for 2 weeks (after 2 weeks of consuming a low fermentable fiber diet) altered the T-cell composition of GALT and produced a higher mitogen response in the predominantly T cell tissues and a lower response in areas involved in B cell functions. In conclusion, the level of fermentable fiber in the diet appears to alter GALT properties. Further studies are required to determine the direct contribution of a high or low fiber diet to these changes and the physiological implications to the health of the animal.

Recovery from lymphocytopenia following extracorporeal circulation: simple indicator to assess surgical stress

This study investigated whether the lymphocyte count is a useful indicator to assess surgical damage following extracorporeal bypass. In Study 1, to investigate the correlation between extracorporeal circulating time (ECCT) and lymphocyte counts, 40 elective CABG patients were studied retrospectively. The lymphocyte recovery ratio (LRR), which represented the actual lymphocyte count divided by the preoperative lymphocyte count, was determined preoperatively, and on postoperative day (POD) 1, POD 3, and POD 5. In Study 2, the correlation between the interleukin-8 (IL-8) level and LRR was examined prospectively in elective CABG patients (n = 20). We measured the LRR and serum IL-8 levels preoperatively and during extracorporeal circulation (ECC) at 5 min, at the end of ECC, and 1, 3, and 12 h following ECC termination. Study 1 showed that the LRR decreased until POD 1 and gradually increased thereafter. The LRR had a negative correlation with the ECCT. In Study 2, the IL-8 level demonstrated a time course opposite to that of the LRR; it increased until 3 h after ECC termination and declined thereafter. There was a significant negative correlation between the LRR on POD 3 and the IL-8 level at 3 h after ECC termination. In summary, long-term ECC induced significant and prolonged lymphocytopenia. The LRR had a negative correlation with IL-8. These results indicated that the LRR may represent the degree of surgical stress following ECC; therefore, the counting of lymphocytes can be a quite useful bedside monitor to assess surgical damage and prognosis.