Characterization of suppressor cells generated in mice after surgical trauma

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.

Urinary neopterin and kynurenine in patients submitted to surgical stress with different inhalational anesthetics (halothane or isoflurane)

Measurements were taken of urinary levels of neopterin (NPT) and kynurenine (KYN), using an HPLC method for their simultaneous analysis in patients submitted to anesthetical surgical stress with two different inhalational anesthetics (halothane and isoflurane). We studied twenty-one women affected by uterine fibromyomatosis and submitted to total hysterectomy (mean age of 42.7+/-5.4 years). They showed the same pre-operative evaluation (ASA-1), and underwent the same i.v. anesthetic treatment. Our patients were randomized in two groups: Group A: 11 patients had halothane as an inhalational anesthetic drug for the maintenance of the anesthetic induction (mean time= 1 h). Group B: 10 patients had isoflurane. A significant decrease in urinary NPT and KYN, parallel to serum-NPT, was found 4 h after anesthetic induction. Raised NPT levels appeared 24 h after A.I. with significant increased levels after 7 days. A strong correlation between urinary and serum NPT levels was seen (Rs= 0.74; p < 0.001). Significantly low KYN levels were observed both 4 h and 24 h after A.I.. In addition to the delayed increase of the excretory KYN levels, significantly raised KYN levels in Group B (isoflurane) 48 h after A.I. (10.59+/-14.31 vs 5.99+/-7.17 micromol/mol creat.; p < 0.01) were shown, whereas in Group A (halothane) we observed a progressive increase as compared to the pre-surgery values starting from 72 h after surgery. Our data seem to show that: (a) it is possible to have a biochemical and non invasive monitoring of the anesthetical-surgical stress on MM "priming" activity; (b) the activation of the phagocyte compartment is one of the earlier immunological events after surgery (NPT), but the efficiency of this "priming" appears to be delayed (KYN); (c) isoflurane appears to induce an earlier recovery in MM activation.

A pilot study of adjuvant hepatic arterial infusion chemotherapy, associating 5-fluorouracil and leucovorin, after resection of colorectal cancer liver metastases

We initiated a pilot study of adjuvant hepatic arterial infusion chemotherapy (AHAIC) using 5-fluorouracil (5-FU) and leucovorin. Hepatic arterial infusion ports were placed in 15 consecutive patients undergoing curative resection of colorectal liver metastases. The chemotherapy regimen consisted of a weekly infusion of 5-FU (12 mg m 2 per day) and leucovorin (200 mg m 2 per day) for 12 months. The mean follow-up was 22 months (range 3-62 months, SD 21-37 months). There were no clinical or biological complications related to chemotherapy, except for sharp epigastric burns in four patients immediately after 5-FU infusions. Catheter irreversible occlusions led to early cessation of the treatment in three patients. Four of the 15 evaluable patients developed recurrent disease. The site of relapse was the liver in two patients and extra-hepatic sites in the two remaining patients. Three of these four patients died of their recurrent disease. These results suggest that 5-FU and leucovorin can be combined for AHAIC in a long duration regimen with a very low rate of side-effects. This protocol could be safely employed in a prospective randomized study in combination with 5-FU systemic infusions.

Surgical trauma, Candida infection, and serum proteolytic activity

Both surgical trauma and infection can disturb the proteinase to proteinase inhibitor balance in the circulation. We sought to assess the effect of Candida albicans infection (INFX) on postoperative mortality, to correlate mortality with total serum proteolytic activity (PA), and to assess the impact of exogenous proteinase inhibitors (PI) on this mortality. Mice underwent midline laparotomy (LAP) and immediate postoperative intravenous C. albicans infection. LAP + INFX shortened mean survival compared to INFX or LAP alone. Quantitative renal cultures confirmed that death in the LAP + INFX and INFX groups was due to Candida sepsis. PA was measured using an 125I-labeled protein assay, yielding micrograms of acid-soluble peptides/100 microliters of serum. In control, sham-operated, and LAP groups, PA averaged less than 9.0, and mortality was 0. In INFX and LAP + INFX groups, PA averaged greater than 14.5 and mortality was high. To determine if high PA was related to high mortality, LAP + INFX mice were treated immediately preoperatively with a single dose of PI (1 mg alpha 1-proteinase inhibitor, 1 mg antithrombin, and 1000 KIU aprotinin). Mean survival increased with PI treatment. In conclusion, the addition of Candida infection to surgical trauma hastened mean time to death. More rapid death correlated with elevated PA and may reflect systemic imbalance in the proteinase to proteinase inhibitor ratio in the circulation. PI improved survival, suggesting that proteinase inhibition may prove useful in the future in the treatment of fungal sepsis in surgical patients.

Perioperative blood transfusions are associated with decreased time to recurrence and decreased survival after resection of colorectal liver metastases

Data from fifty-five patients who had hepatic resections for colorectal liver metastases at the National Cancer Institute (NCI) were analyzed to determine the effect of perioperative blood transfusions on disease recurrence and overall survival. Besides blood transfusions, other factors included in the analysis were size, number, and distribution of metastases, margin status of resected metastases, length of disease-free interval, Duke's stage of the primary tumor, type of hepatic resection, and anesthesia time. Using the Cox proportional hazards model, the amount of blood transfused was found to be a significant prognostic factor. For each additional unit of blood transfused the risk of disease recurrence and death was increased by 5% (p = 0.0015) and 7% (p = 0.0013), respectively. The median disease-free survival for patients who received 3-5, 6-10, and greater than or equal to 11 transfused units was 26, 12.1, and 11.4 months, respectively. The median overall survival for patients who received 3-5, 6-10, and greater than or equal to 11 transfused units was greater than 44, 39.2, and 33.6 months, respectively. The number of resected nodules (1-2 vs. greater than or equal to 3), type of resection (anatomic lobectomy vs. wedge resection), and nodule size (less than or equal to 3.0 cm vs. greater than 3.0 cm) were additional factors that were further evaluated to determine the effect of blood transfusions. Analyses stratified for each of these factors revealed that patients who received greater than or equal to 11 units of blood had a significantly decreased disease-free and overall survival compared with patients who received 3-10 units of blood. It is concluded that the amount of perioperative blood transfused is an independent prognostic factor that adversely effects disease-free and overall survival.

Changes in cellular immunity and nutritional status in mice after thermal injury

A 13 per cent body surface area (BSA), full skin thickness burn was inflicted on LACA male mice and the changes in cellular immunity and nutritional status were observed. The results showed that thymus, spleen and circulating lymphocytes were significantly involved. A diminished mitogen responsiveness of spleen cells and altered peritoneal macrophage function were confirmed. Ear swelling tests indicated that the cellular immunity of burned mice was most severely depressed in week 2 postburn. The present study also showed that the dramatic change in nutritional status occurred earlier than that in cellular immunity and suggested the importance of early nutritional support after thermal injury.

Decreased neutrophil thromboxane A2 and endothelial PGI2 production in the postoperative period. An in vitro assay for detection of neutrophil and plasma dysfunction

Severe trauma results in reversible abnormalities in neutrophil function, but the specific role in the pathogenesis of postoperative sepsis is undetermined. Twenty adult patients undergoing elective surgical procedures were studied. Blood samples were obtained prior to and 24 hours after operation. Blood neutrophils were isolated and incubated (10(7) cells/mL) on bovine vascular endothelial cell monolayers. Untreated plasma or zymosan-activated plasma (ZAP) or 65 C inactivated plasma was added, and TxB2 and 6-keto PGF1 alpha production measured after 2 hours. Endothelial damage was detected by light and scanning electron microscopy beginning 2 and 4 hours after treatment. Preoperatively, neutrophil TxB2 release was less than 200 pg/mL; following ZAP it was 2153 pg/mL (p less than 0.001), with untreated plasma 1055 pg/mL (p less than 0.005) and inactivated plasma 764 pg/mL (p less than 0.01). Neutrophil TxB2 release on a plastic dish was not different from incubation on endothelium. Endothelial 6-keto PGF1 alpha release following addition of untreated plasma preoperatively was 1308 pg/mL (p less than 0.01), and with ZAP 1305 pg/mL (p less than 0.01). Activated neutrophils did not alter 6-keto PGF1 alpha production. Postoperatively, neutrophil TxB2 production in response to ZAP was 1092 pg/mL, which was significantly reduced compared to the preoperative response (p less than 0.01). Endothelial damage by activated neutrophils in the postoperative period demonstrated on scanning electron microscopy was also reduced; 6-keto PGF1 alpha release in the postoperative period inducted by ZAP was 569 pg/mL and by untreated plasma 549 pg/mL, which was significantly lower than in the preoperative period (p less than 0.05 and p less than 0.05, respectively). No difference in chemotaxis was demonstrated. It is concluded that operative trauma is followed by lowered neutrophil TxB2 release, appearance of a plasmatic factor that depresses endothelial 6-keto PGF1 alpha production, as well as decreased neutrophil-induced endothelial damage. The neutrophil-endothelial monolayer system is a sensitive method for detection of neutrophil and plasmatic dysfunction.

Effect of stress and trauma on bacterial translocation from the gut

Previously, we established that bacteria contained within the gut can cross the GI mucosal barrier and spread systemically, a process termed bacterial translocation. Three models were used to extend this work: cold exposure (up to 16 hr at 4 degrees C), a nontissue injury stress model; femoral fracture-amputation, a trauma model; and thermal injury (30% third-degree burn), a trauma model with retained necrotic tissue. CD-1 mice either with a normal GI microflora or who were monoassociated with Escherichia coli C-25 were subjected to sham or actual stress or trauma. The animals were sacrificed at various times postinsult and the ceca, mesenteric lymph nodes (MLN), spleens, and livers were quantitatively cultured. Neither the incidence nor the magnitude of bacterial translocation was increased in the cold-exposed animals compared to control mice. The incidence of bacterial translocation to the systemic organs was higher in the animals with a normal flora receiving femoral fracture amputation (11%) (P less than 0.02) than in animals receiving a thermal injury (1%) or sham-injured control mice (0%). In contrast, the incidence of translocation to the liver or spleen was higher in burned mice monoassociated with E. coli C-25 (60%) (P less than 0.01) than in E. coli monoassociated mice sustaining femoral fracture amputation (17%). Stress alone (cold exposure) does not promote bacterial translocation; however, trauma, especially in combination with retained necrotic tissue, promotes bacterial translocation. Thus bacteria colonizing the gut can invade systemic organs after trauma, especially when the normal ecology of the gut flora has been disrupted.

Prevention of alterations in postoperative lymphocyte subpopulations by cimetidine and ibuprofen

Surgical procedures probably result in a temporary state of immunosuppression. Identification of functional lymphocyte subclasses using appropriate monoclonal antibodies appears to serve as a sensitive, accurate, and reproducible measure of immune status in patients in many disease states. Using monoclonal antibodies specific for lymphocyte surface markers and immunofluorescent assay, we quantitated lymphocyte subpopulations in patients undergoing surgical procedures. Cholecystectomy, colon surgery, and coronary bypass procedures all resulted in postoperative decreases in helper and inducer populations and increases in cytotoxic suppressor populations, with resultant depressions in the helper to suppressor lymphocyte ratio. Studies in an additional group of patients who underwent cholecystectomy demonstrated that these changes could be prevented by perioperative administration of ibuprofen and cimetidine. These results suggest that prostaglandins and histamines are involved in immunoregulatory events after major operation. The ability of specific pharmacologic therapy to prevent alterations in lymphocyte populations suggest that postoperative immunity may be preserved, hopefully leading to greater host resistance against infection and tumor dissemination.

Immunologic mechanisms underlying sepsis in the critically ill surgical patient

This article describes the range of immunologic abnormalities that follows accidental and operative trauma. The high rate of infection in critically ill postoperative patients may result from these abnormalities in host defense function. Means to recognize and correct the post-trauma immune deficiencies are discussed.

Serum-mediated depression of neutrophil chemiluminescence following blunt trauma

To investigate one possible mechanism responsible for decreased neutrophil bactericidal activity following trauma, the chemiluminescence response of normal neutrophils was measured following incubation in nonseptic and septic serum from 19 blunt trauma patients. Incubation of normal neutrophils in septic patients' sera (61 studies) resulted in a marked decrease in the chemiluminescence response (36 +/- 26% of control), compared to incubation in nonseptic sera (92 studies, 80 +/- 53% of control; p less than 0.005). This difference between nonseptic and septic serum was apparent immediately after injury, prior to the development of sepsis (47 +/- 4% versus 77 +/- 12%; p less than 0.05). The depression of the CL response was due to a suppressive factor present in septic patients' sera. This factor was nondialyzable and was present in high performance liquid chromatography (HPLC) fractions containing protein of molecular weight 50 to 100,000. Removal of albumin using Affigel-blue did not remove the suppressive factor. In contrast to the suppressive effect of septic trauma serum, septic patients' neutrophils had a normal chemiluminescence response after their isolation and washing. We conclude that trauma results in the generation of a serum factor that suppresses neutrophil chemiluminescence and that is present in greater amounts in patients who eventually become septic. This factor may be responsible for the decreased bactericidal activity and depressed host defense following injury.

Immunologic effects of nonsteroidal anti-inflammatory agents

The author discusses the evidence that PGE is an immunomodulator and addresses the thesis that nonsteroidal anti-inflammatory agents, by blocking endogenous PGE production, act to partially correct the immunologic aberrations involved in the pathogenesis of rheumatoid arthritis.

Wound-induced alterations in survival of 60Co irradiated mice: importance of wound timing

Wounding mice shortly before or shortly after lethal 60Co irradiation enhances survival. Survival of wounded-irradiated mice may be due to enhanced hematopoietic recovery as measured by endogenous spleen colony (E-CFU-s) formation.

Hematopoietic colony-forming cells from mice after wound trauma

The changes produced in the pluripotential and progenitor cell compartments of the hind leg bone marrow and spleen of skin-wounded mice were examined over a 2-week post-trauma period. Pluripotent cells (colony-forming unit-spleen, CFU-s) were significantly increased in the spleen and slightly reduced in the leg marrow the first week after trauma. Granulocyte macrophage colony-forming cells (GM-CFC) were significantly increased in the spleen throughout the 2-week period and were increased in the leg marrow during the first post-trauma week. Macrophage colony-forming cells (M-CFC) were significantly decreased in the spleen during the 2-week period and were slightly elevated in the leg marrow during that time. The peripheral blood contained significantly increased concentrations of CFU-s and GM-CFC but not M-CFC. Serum of wounded mice supported growth of GM-CFC but not M-CFC. The growth-promoting factor was extractable by CHCl3 treatment. Serum C-reactive protein concentrations were significantly increased for a 5-day period after wound trauma.

Characterization of the immunosuppressive effect of burned tissue in an animal model

The immunosuppressive effect of burned tissue was studied using a mouse burn model. To evaluate the immunologic status an in vivo measure of cell-mediated immunity (CMI) involving contact sensitization of mice by painting the skin with dinitrofluorobenzene was used; mice were challenged 5 days later by painting the ear with the same antigen. Ear swelling in response to antigenic challenge was used as a quantitative measure of CMI; diminution in ear swelling in treatment mice compared to sensitized, unburned control mice indicated the degree of immunosuppression. A full-thickness steam burn covering 20% body surface ares (BSA) was profoundly immunosuppressive as reflected by ear swelling of 45 to 60% of that found in normal mice; partial thickness burns and burns of 10% BSA extent were not significantly immunosuppressive. Transfer into unburned mice of burned skin equivalent in size to a 20% BSA burn eschar resulted in marked immunosuppression, but transfer of smaller amounts of burned skin, or of larger amounts of unburned skin and normal and burned liver tissue, did not produce immunosuppression. Mice receiving a very high-temperature (300 degrees C), dry burn were only slightly more suppressed than mice receiving a standard steam burn. Normal immunity was preserved in burned mice which received daily application of cerium nitrate to the wound for 7 days, but application of other topical agents commonly used in burn treatment did not preserve immunity. Postburn immunosuppression thus appears related quantitatively to toxic factors in burned skin, and these toxic factors can be abrogated in burned mice by the topical application of cerium nitrate.

Immunologic effects of nonsteroidal anti-inflammatory drugs

Recent studies of the immunoregulatory effects of prostaglandin and the immunomodulating actions of nonsteroidal anti-inflammatory drugs reveal that earlier reports of inhibition of prostaglandin synthesis by nonsteroidal anti-inflammatory drugs cannot alone fully explain the anti-inflammatory properties of these agents. Data defining the complex inter-relationship of prostaglandin, the immune response, and nonsteroidal anti-inflammatory drugs are reviewed, and possible mechanisms of anti-inflammatory action of these agents are considered. The effects of nonsteroidal anti-inflammatory drugs on cellular immune function and humoral immune response suggest that anti-inflammatory activity may be related to altered suppressor cell function, inhibition of monocyte collagenase release, or inhibition of neutrophil migration and activation. Further elucidation is awaited.

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

Although a wealth of evidence has suggested that cell-mediated immunity is suppressed after simple surgical trauma, there have been contradictory results using stimulation assays of lymphocyte function. We quantitated T-lymphocyte subsets in 11 patients undergoing routine cholecystectomy by immunofluorescence microscopy using specific monoclonal antibodies. T-helper to T-suppressor cell ratios were calculated on the preoperative day and the first postoperative day in all patients, and on the third or fourth postoperative day in five patients. Helper to suppressor ratios decreased in all patients on the first postoperative day (p greater than 0.01), but returned to within normal limits on subsequent days. Changes were due more to decreases in helper cells than to increases in suppressor cells, although changes in both populations were statistically significant. The measurement of T-cell subsets by antibody-specific labeling and immunofluorescence microscopy may prove to be a more sensitive, quantifiable, and reproducible assay of immune function in surgical or traumatized patients than use of stimulation assays. Measurements of specific helper and suppressor lymphocyte populations may prove useful in predicting morbidity and mortality, and may also help in studying the effect of immunomodulating agents on the immune response.

Regulation of the immune response by prostaglandins

Of all the arachidonic acid metabolites, only prostaglandin E (PGE) has been shown to have a clear role in the regulation of cellular and humoral immune responses. In cellular immune responses such as T cell proliferation, lymphokine production, and cytotoxicity, PGE usually acts as a feedback inhibitor of the response. This is also true of macrophage and natural killer cytotoxicity. In some instances PGE is responsible for cellular activation rather than inhibition. This is clearest in the control of humoral immunity, where PGE production is a necessary component in the generation of some type of T suppressor cells. Disturbances in immune function found in several human conditions and diseases have been linked to changes in PGE mediated immunoregulation. Either increased production of PGE or increased sensitivity to PGE results in depressed cellular immunity. Conversely drugs which inhibit PGE production act as stimulants of cellular immune function in vitro and in vivo.