Urinary neutrophil chemotactic factors in interstitial cystitis patients and a rabbit model of bladder inflammation.

The present study investigates a possible source of inflammatory mediators involved in the pathogenesis of bladder inflammation characteristics of interstitial cystitis disease. Our tested hypothesis is that in response to injury, tissues of the urinary bladder participate in the initiation of bladder inflammation by releasing inflammatory mediators such as neutrophil chemotactic factors. Bladders of anesthetized rabbits (n = 7) were instilled with an acidic solution (pH 4.5) for 15 minutes, then washed with saline and instilled with sterile phosphate buffered saline (PBS) (pH 7.2) for an additional 45 minutes prior to sacrificing the rabbits. Control rabbits (n = 7) were instilled with sterile PBS (pH 7.2) for 15 minutes, then 45 minutes. The levels of neutrophil chemotactic factors were measured using modified Boyden chambers and rabbit peritoneal neutrophils as indicator cells. Results indicated the release of high levels of neutrophil chemotactic factors (via a checkerboard analysis) from acid-treated bladders after 15 minutes (70 +/- 4% of standard) and 45 minutes (80 +/- 7%). Electron microscopy analysis of these acid-treated bladders revealed the infiltration of a large number of neutrophils, which correlates with the recovery of neutrophil chemotactic factors. Control rabbits, on the other hand, showed low levels of chemotactic activity (less than 10 percent) and exhibited normal bladder morphology with absence of neutrophils. The glycosaminoglycan (GAG) layer was intact in both acid-treated and control bladders. High levels of neutrophil chemotactic factors were also detected in urine samples from eleven patients with interstitial cystitis (113 +/- 25%) (not due to interleukin-1 or leukotriene B4) which were not detected in urine samples from healthy volunteers (n = 9) or from thirteen control patients with bladder diseases other than interstitial cystitis. These preliminary studies indicate the capability of injured bladder tissues to release neutrophil chemotactic factors which contribute to the initiation of bladder inflammation. The presence of neutrophil chemotactic factors in urine samples of interstitial cystitis patients suggests a possible role of these mediators in the pathogenesis of the disease.     

Cardiac-derived neutrophil chemotactic factors: detection in coronary sinus effluents of patients undergoing myocardial revascularization.

Recent studies from our laboratory have demonstrated the release of neutrophil chemotactic factors from isolated rabbit hearts perfused with cardioplegic solutions and from ischemic dog hearts after coronary artery occlusion for 1 hour. On the basis of these animal studies, a test is now made of the hypothesis that neutrophil chemotactic factors are released by myocardial tissues of patients who undergo surgical myocardial revascularization. By means of modified Boyden chambers, the levels of neutrophil chemotactic factors were measured in effluent collected from the coronary sinuses of six patients undergoing cardiopulmonary bypass during periods of cold cardioplegia. Plain cardioplegic solutions were also analyzed. The standard formyl-methionyl-leucyl-phenylalanine, a stimulant of neutrophil recruitment, was used as a positive control solution. Results indicated the recovery of significantly high levels of neutrophil chemotactic factors in patient samples (i.e., 128% +/- 19% of formyl-methionyl-leucyl-phenylalanine) compared with control plain cardioplegic solution (less than 5% of formyl-methionyl-leucyl-phenylalanine) (p less than 0.0001). A standard checkerboard analysis indicated that the observed activity is chemotactic (i.e., directed migration) and not chemokinetic (i.e., random migration). This study also showed that these factors are proteins of a molecular weight in excess of 300 kd and exhibit in vivo activity by recruiting neutrophils into rabbit skin. The absence of immune cell-derived chemoattractants such as interleukin-1 and leukotriene B4 in these coronary sinus effluents suggests that the observed chemotactic activity is cardiac derived. Results of this investigation therefore demonstrate the release of neutrophil chemotactic factors by ischemic human hearts during cardiopulmonary bypass.     

Role of alveolar macrophages in asbestosis: modulation of neutrophil migration to the lung after acute asbestos exposure.

After intratracheal injection of short chrysotile asbestos fibres in guinea-pigs an intense neutrophil alveolitis was observed within three days. Evaluation by bronchoalveolar lavage of the inflammatory and immune effector cells producing the alveolitis by three days showed an increased proportion of polymorphonuclear leucocytes, which comprised 21% +/- 3% of the total leucocytes compared with 9% +/- 2% for the controls (p less than 0.05), persisting for at least six weeks (after which time the polymorphonuclear leucocytes comprised 28% +/- 2% compared with 7% +/- 1% for the controls: p less than 0.05). One mechanism by which asbestos fibres may cause polymorphonuclear leucocytes to be attracted to the alveolar structures is by induced release of neutrophil chemotactic factor by alveolar macrophages. When exposed in vitro to short or intermediate chrysotile fibres or amosite or crocidolite fibres guinea-pig alveolar macrophages released appreciable amounts of neutrophil chemotactic factor. The release of this chemotactic factor was augmented when the asbestos fibres had been previously exposed to normal serum. The chemotactic factor was lipid soluble, and was similar to the neutrophil chemotactic factor spontaneously released by alveolar macrophages recovered from guinea-pigs exposed in vivo to short chrysotile fibres. These observations suggest that alveolar macrophages may play an important part in the early stages of asbestosis by modulating the migration of neutrophils to the lung.     

Helicobacter pylori products upregulate neutrophil superoxide anion production

Helicobacter pylori-neutrophil interactions may play a pathogenic role in H. pylori-induced gastritis and peptic ulcer disease. To understand these interactions, we explored the effects of H. pylori-derived products on neutrophil chemotaxis and superoxide anion production. H. pylori bacteria were cultured and supernatants fractionated. Neutrophil chemotactic activity was confirmed in the crude supernatants and in one fractionated peak corresponding to a previously described neutrophil chemotactic factor. H. pylori-derived crude supernatant, sonicate and all chromatography-derived peaks failed to directly stimulate neutrophil superoxide anion production. However, after pretreatment with sonicate, neutrophils demonstrated increased superoxide anion production (priming) following subsequent exposure to the secretagogue fmet-leu-phe. These results suggest that H. pylori products may attract neutrophils to the gastric mucosa without initially stimulating superoxide anion production or tissue injury. Oxygen radical-mediated gastric mucosal injury may subsequently result when these primed neutrophils undergo additional stimulation by as yet unidentified factors.     

Neutrophil chemotaxis and neutrophil elastase in the aortic wall in patients with abdominal aortic aneurysms.

To test the hypothesis that elastin-derived peptides (EDP) from human aortic tissue may be chemotactic for inflammatory cells, we studied the chemotaxis of neutrophils and monocytes to EDP derived from abdominal aortic aneurysm (AAA), aortic occlusive disease (AOD), and control aortas. In addition, we determined if neutrophils deliver neutrophil elastase to the aorta in vivo by staining for neutrophil elastase (NE) throughout the course of abdominal aortic aneurysms with the monoclonal antibody to human NE. EDP from AAA, AOD, and control tissue demonstrated significant chemotactic activity for both neutrophils and monocytes. All neutrophils had a greater attraction to EDP from AAA tissue compared to AOD and control aorta. Neutrophils from AAA patients were more attracted to EDP of AAA tissue than were neutrophils of AOD or control patients attracted to their respective aortic EDP. Neutrophil elastase stained positive in the adventitia and thrombus throughout the course of the aneurysm, but was not found in the intima, media, or plaque of the aorta.     

Neutrophils from patients undergoing hip surgery exhibit enhanced movement under spinal anaesthesia compared with general anaesthesia

The purpose of this research was to investigate whether the effects of regional anaesthesia on neutrophil migration differ from those due to general anaesthesia during major orthopaedic surgery in human patients. Eighteen patients underwent spinal or general anaesthesia (halothane or isoflurane) for surgery (six patients in each group). Blood samples were taken prior to induction of anaesthesia and after surgery was in progress for one hour. The movement of isolated neutrophils was measured in both samples in the chemotactic chamber toward lipopolysaccharide activated pooled serum. In addition plasma concentrations of catecholamines were determined in the blood samples. Neutrophils extracted from peripheral blood during spinal anaesthesia and surgery moved further towards a complement-derived attractant than neutrophils obtained from patients undergoing surgery under general anaesthesia with halothane or isoflurane and surgery (156.4 +/- 7.6 microns vs 114.3 +/- 6.1 microns or 119 +/- 8.4 microns respectively, P < 0.05). Increased concentrations of adrenaline were present in both general anaesthetic groups whereas the spinal group had lower concentrations than those prior to anaesthesia and surgery. It is considered unlikely that these differences in neutrophil reactivity are due to the direct effects of anaesthetic agents employed. The effects are likely to be the result of differing effects of spinal anaesthesia on the stress response or immunological mediators.     

Sputum chemotactic activity in chronic obstructive pulmonary disease: effect of alpha(1)-antitrypsin deficiency and the role of leukotriene B(4) and interleukin 8

BACKGROUND: Neutrophil recruitment to the airway is thought to be an important component of continuing inflammation and progression of chronic obstructive pulmonary disease (COPD), particularly in the presence of severe alpha(1)-antitrypsin (alpha(1)-AT) deficiency. However, the chemoattractant nature of secretions from these patients has yet to be clarified. METHODS: The chemotactic activity of spontaneous sputum from patients with stable COPD, with (n=11) and without (n=11) alpha(1)-AT deficiency (PiZ), was assessed using the under-agarose assay. The contribution of leukotriene B(4) (LTB(4)) and interleukin 8 (IL-8) to the chemotactic activity was examined using an LTB(4) receptor antagonist (BIIL 315 ZW) and an IL-8 monoclonal antibody, respectively. RESULTS: Sputum neutrophil chemotactic activity (expressed as % n-formylmethionyl leucylphenylalanine (fMLP) control) was significantly higher in patients with alpha(1)-AT deficiency (mean (SE) 63.4 (8.9)% v 36.7 (5.5)%; mean difference 26.7% (95% CI 4.9 to 48.4), p<0.05). The mean (SE) contribution of both LTB(4) and IL-8 (expressed as % fMLP control) was also significantly higher in alpha(1)-AT deficient patients than in patients with COPD with normal levels of alpha(1)-AT (LTB(4): 31.9 (6.3)% v 18.0 (3.7)%; mean difference 13.9% (95% CI -1.4 to 29.1), p<0.05; IL-8: 24.1 (5.2)% v 8.1 (1.2)%; mean difference 15.9% (95% CI 4.7 to 27.2), p<0.05). When all the subjects were considered together the mean (SE) contribution of LTB(4) (expressed as % total chemotactic activity) was significantly higher than IL-8 (46.8 (3.5)% v 30.8 (4.6)%; mean difference 16.0% (95% CI 2.9 to 29.2), p<0.05). This difference was not significantly influenced by alpha(1)-AT phenotype (p=0.606). CONCLUSIONS: These results suggest that the bronchial secretions of COPD patients with alpha(1)-AT deficiency have increased neutrophil chemotactic activity. This relates to the increased levels of IL-8 and, in particular LTB(4), which accounted most of the sputum chemotactic activity in the patients with COPD as a whole. Increased chemotactic activity, together with inhibitor deficiency, may contribute to the more rapid disease progression seen in alpha(1)-AT deficiency via increased neutrophil recruitment and release of neutrophil elastase.     

Effect of fluticasone propionate on neutrophil chemotaxis, superoxide generation, and extracellular proteolytic activity in vitro.

BACKGROUND--Corticosteroids are widely used in the treatment of many inflammatory conditions but the exact mode of action on neutrophil function is uncertain. Fluticasone propionate is a new topically active synthetic steroid which can be measured in body fluids and which undergoes first pass metabolism. METHODS--The effects of fluticasone propionate on the function of neutrophils isolated from normal, healthy control subjects and on the chemotactic activity of sputum sol phase were assessed. RESULTS--Preincubation of neutrophils with fluticasone propionate reduced the chemotactic response to 10(-8) mol/l F-Met-Leu-Phe (FMLP) and to a 1:5 dilution of sputum sol phase in a dose dependent manner. Furthermore, when fluticasone propionate was added to sputum from eight patients with stable chronic obstructive bronchitis the chemotactic activity of a 1:5 dilution of the sol phase fell from a mean (SE) value of 22.2 (1.21) cells/field to 19.6 (0.89), 17.1 (0.74), and 11.9 (0.6) cells field at 1 mumol/l, 10 mumol/l, and 100 mumol/l, respectively. In further experiments fluticasone propionate preincubated with neutrophils inhibited fibronectin degradation by resting cells and by cells stimulated by FMLP (15.2% inhibition of resting cells, 5.1% inhibition of stimulated cells with 1 mumol/l fluticasone propionate, 24% and 18.7% inhibition respectively at 100 mumol/l fluticasone propionate. Fluticasone propionate had no effect on generation of superoxide anion by resting or stimulated cells. CONCLUSIONS--These results indicate that fluticasone propionate has a direct suppressive effect on several aspects of neutrophil function and may suggest a role for this agent in the modulation of neutrophil mediated damage to connective tissue.     

Neutrophil function in surgical patients. Relationship to adequate bacterial defenses

Chemotaxis under agarose and the beta-glucosaminidase enzyme-release assay (BGERA) were evaluated for assessing neutrophil function in 44 patients in a surgical intensive care unit (SICU). The 27 patients shown to be angeric to delayed-type hypersensitivity skin tests at entry to the SICU had decreased neutrophil chemotaxis of 2.6 +/- 0.2 cm (mean +/- SEM) and a decreased BGERA result of 22.4% +/- 1.6%. Major sepsis developed in 59% of them, and 44% died. The ten relatively anergic patients (reacting to one antigen) had a normal neutrophil chemotactic response of 3.0 +/- 0.2 cm and a decreased BGERA result of 20.9% +/- 1.6%. Sepsis developed in 30% of them, and 20% died. The seven reactive patients (reacting to two or more antigens) had a neutrophil chemotaxis of 3.7 +/- 0.3 cm and a BGERA result of 18.9% +/- 1.7%. None had sepsis or died. The agarose method correlated best with the delayed-type hypersensitivity response. The BGERA results did not correlate with neutrophil chemotaxis and were not helpful in gauging neutrophil function.     

Neutrophil activation--an important cause of tissue damage during liver allograft rejection?

Although neutrophils have been implicated as mediators of tissue damage in a variety of conditions, their role in graft rejection has not previously been studied. Peripheral neutrophil activation was assessed sequentially in 16 patients following liver transplantation by measuring the ability of neutrophils to respond to the chemotactic peptide FMLP, to release superoxide radicals, and to cause extracellular proteolysis. All three functions increased 1-2 days before episodes of acute rejection and only returned to normal after treatment with high-dose corticosteroids. Three patients who did not develop rejection showed no increase in neutrophil function. Lymphocytes isolated from patients with acute rejection produced factors that were both chemotactic for and capable of activating normal neutrophils. This study shows that neutrophil activation occurs during acute liver allograft rejection, possibly in response to lymphokine secretion, and suggests an important, and hitherto unrecognized, mechanism of graft damage during rejection.     

Regulation of neutrophil migratory function in burn injury by complement activation products.

Polymorphonuclear neutrophils were isolated from patients with burn injury and random mobility, chemotaxis in response to C5adesArg (as agarose-activated control serum) and to N-formyl-methionyl-leucyl-phenylalanine (F-Met-Leu-Phe) were assessed. For a group of eight patients identified as not experiencing systemic infection, all three neutrophil migratory functions were observed to fall below control levels, beginning 4 to 6 days following burn injury, and to return to control levels after 21 to 30 days of hospitalization. Over this time the chemotactic differential (distance chemotactic migration-distance random migration) for F-Met-Leu-Phe remained positive, while the chemotactic differential for activated serum became nil after postburn day 4. This temporal, specific loss of a chemotactic response to activated serum was associated with rises in immunoreactive plasma C3a and C5a. This pattern of loss of chemotactic function was associated with a selective loss of C5a but not F-Met-Leu-Phe binding activity. These results demonstrate that burn injury can alter neutrophil migratory functions generally, and specifically depress chemotactic responsiveness to activated serum. The mechanism of the latter phenomenon appears to be related to desensitization of circulating neutrophils to C5a due to complement activation.     

Neutrophil Function in Anergic Surgical Patients: Neutrophil Adherence and Chemotaxis

Skin test anergy (A) to recall antigens identifies surgical patients at high risk for sepsis. We studied neutrophil function in such patients to assess any alteration in their host defense mechanisms. Neutrophil adherence was measured with a modified adherence assay capable of measuring the adherence of neutrophils in whole blood or purified neutrophil suspensions, and neutrophil chemotaxis was assessed by the Boyeden technique. Twenty-one laboratory controls had a neutrophil adherence of 71.5 +/- 3.8% (mean +/-SD) and chemotaxis of 128.1 +/- 2.4,micro (mean +/-SD). Fifty-four hospitalized patients with normal skin tests had neutrophil adherence of 72.5 +/- 13.1% (p ~ 0.5 relative to control) and chemotaxis of 123.3 +/- 3.1 micro (p ~ 0.5). Twenty three relatively anergic patients had values of 84.3 +/- 7.9% (p < 0.001) and 103.7 +/- 2.0 micro (p < 0.001). Forty five A patients had adherence of 85.0 +/- 7.0% (p < 0.001) and chemotaxis of 90.4 +/- 2.9 micro (p < 0.001). The correlation coefficient between increased neutrophil adherence and decreased chemotaxis r = 0.81 has p < 0.0005. A factor which increased the adherence of normal control neutrophils was found in the plasma but not the serum of anergic patients. Inhibitors of control neutrophil chemotaxis have been shown in both serum and plasma of patients with decreased autologous neutrophil chemotaxis. We propose that this altered neutrophil function (possibly with other defects) in anergic patients may compromise their host defenses and render them susceptible to infection.     

Inhibition of neutrophil chemotaxis by plasma of burned patients: effect of blood transfusion practice

Incubation of normal human neutrophils with plasma from burned patients markedly reduced the ability of the cells to respond to a chemotactic stimulus in vitro. Previous transfusion of the patients with packed red blood cells did not alter the inhibited locomotion of neutrophils, whereas transfusion with normal plasma alone attenuated or even abolished the inhibitory activity. The finding provides direct evidence for the involvement of circulating suppressive factors in neutrophil chemotaxis, rendering burned patients more susceptible to infections. In addition, it stresses the relevance of plasma transfusion in clinical management and infection control following thermal injury.     

Xenon preserves neutrophil and monocyte function in human whole blood

PURPOSE: Most volatile anesthetics are known to inhibit the oxidative and phagocytic function of neutrophils. In the present study, we investigated the effect of xenon on phagocytosis and respiratory burst activity of neutrophils and monocytes in human whole blood. METHODS: Heparinized whole blood from 22 healthy volunteers was incubated for 60 min in the presence of 65% xenon. Sixty-five percent nitrous oxide was used as a positive control to prove the reliability of our in vitro system. Phagocytosis of fluorescein isothiocyanate labelled, opsonized Escherichia coli (E. coli) by neutrophils and monocytes was measured using flow cytometry. After induction with either N-formyl-methionyl-leucyl-phenylalanine (FMLP), phorbol-12-myristate-13-acetate or opsonized E. coli, respiratory burst activity was assessed by measuring the oxidation of dihydrorhodamine 123 to rhodamine 123 with a flow cytometer. RESULTS: Exposure of human whole blood to xenon increased the percentage of neutrophils showing phagocytosis (94 +/- 3% vs 92 +/- 4%; P < 0.01), and the amount of ingested bacteria (P < 0.01). Respiratory burst activity in neutrophils and monocytes was not affected by xenon. Nitrous oxide significantly reduced the percentage of neutrophils showing respiratory burst after FMLP stimulation. Furthermore, E. coli-induced stimulation resulted in a decreased number of reacting neutrophils (84 +/- 15% vs 95 +/- 5%; P < 0.05) and monocytes (70 +/- 22% vs 83 +/- 11%; P < 0.05) as well as a reduced production of hydrogen peroxide in both cell lines compared to control. CONCLUSION: In contrast to nitrous oxide, xenon preserves neutrophil and monocyte antibacterial capacity in vitro.     

Glomerular mesangial cells and inflammatory macrophages ingest neutrophils undergoing apoptosis.

Apoptosis or programmed cell death of senescent neutrophils leading to their uptake by phagocytes is a general mechanism by which neutrophils may be removed from inflamed sites in vivo, promoting resolution rather than persistence of inflammation. We now report morphological evidence of neutrophil apoptosis leading to uptake by glomerular cells in rats with experimental glomerulonephritis. In addition to confirming that inflammatory macrophages take up apoptotic neutrophils, these studies indicated that glomerular mesangial cells can also participate in this mode of neutrophil clearance. Furthermore, human neutrophils which had been "aged" in vitro so as to undergo apoptosis were ingested by 31.5 +/- 1.3% (mean +/- SE) of cultured human mesangial cells, but there was minimal recognition of freshly isolated neutrophils (2.2 +/- 0.1%). Centrifugal elutriation of aged neutrophil populations yielded fractions with varying degrees of apoptosis (from 11.1 to 79.4%). Uptake of these fractions (by 8.2% to 59.8% of mesangial cells) was closely correlated with apoptosis (r = 0.96, P less than 0.0001). This demonstrated that recognition was dependent upon apoptosis, as in previous reports of macrophage recognition of aged neutrophils. However, by contrast, a partial requirement for serum was observed. These data indicate a hitherto unexpected function for the mesangial cell in clearance of senescent neutrophils from the glomerulus which may supplement inflammatory macrophage uptake of leucocytes undergoing apoptosis.     

Murine neutrophils collected from subcutaneously implanted sponges

Polyvinyl sponges implanted subcutaneously in mice were used as a source of murine neutrophils (PMNs). Yield of PMNs from sponges averaged 6.3 X 10(5) PMNs per mouse and viability of sponge PMNs was 96.5%. These results were comparable to the yield and viability of PMNs harvested from peripheral blood. The chemotactic activity of sponge PMNs was significantly greater than the chemotactic activity of peripheral blood PMNs (chemotactic index of 4.78 +/- 1.66 in sponge PMNs versus 2.16 +/- 1.08 in peripheral blood PMNs, P less than 0.001). The difference in chemotactic activity was not attributable to hypotonic injury of PMNs nor the presence of soluble factors in sponge fluids. Phagocytic activity of sponge PMNs was comparable to the activity of blood PMNs (mean of 31.3 +/- 16.4% phagocytic cells for sponge PMNs versus 33.0 +/- 23.9% for blood PMNs). In addition, the number of fluorescent spheres ingested by sponge PMNs was not different (mean of 2.81 +/- 0.86 in sponge PMNs versus 2.65 +/- 0.68 spheres per cell for blood PMNs). These studies indicate that subcutaneously implanted sponges can be used as a source of functioning murine PMNs.     

Interleukin-8: A pathogenetic role in antineutrophil cytoplasmic autoantibody-associated glomerulonephritis

BACKGROUND: In neutrophil trafficking, the role of interleukin-8 (IL-8) is location dependent. Tissue IL-8 directs transmigration, whereas intravascular IL-8 frustrates this process. The bystander damage of glomerular endothelium by antineutrophil cytoplasmic autoantibody (ANCA)-activated neutrophils is believed to be an early event in the pathogenesis of ANCA-associated glomerulonephritis. We have studied the role of IL-8 in this process. METHODS: Intraglomerular expression of IL-8 in patients with ANCA-associated glomerulonephritis was studied by in situ hybridization and immunohistochemistry and location of neutrophils by serial section immunohistochemistry. In vitro, we analyzed ANCA-stimulated neutrophil IL-8 production by enzyme-linked immunosorbent assay, and the IL-8 attributable effect of ANCA-stimulated neutrophil supernatant by chemotactic and transendothelial assays. RESULTS: There was intraglomerular expression of IL-8 at segmental, crescentic, and parietal epithelial sites. IL-8 protein expression colocalized to intraglomerular neutrophils; many localized within glomerular capillary loops, suggesting failed trafficking to tissue IL-8. ANCAs differentially stimulated time- and dose-dependent neutrophil IL-8 production, and ANCA-stimulated neutrophil supernatant demonstrated potent IL-8-dependent chemotactic activity and inhibited transendothelial migration of normal human neutrophils toward an IL-8 gradient. CONCLUSION: Despite heavy tissue expression of IL-8 in ANCA-associated GN, the production of IL-8 by ANCA-stimulated neutrophils within the intravascular compartment may frustrate neutrophil transmigration, encourage intravascular stasis, and contribute to bystander damage of glomerular endothelial cells.     

Influence of serum on impaired neutrophil chemotaxis after thermal injury

Impaired neutrophil chemotaxis has been consistently documented after thermal injury but whether this defect is primarily related to an acquired cellular defect or to humoral factors is not clear. To study this question, serial neutrophil chemotaxis measurements using the agarose technique of chemotaxis, were made in 34 patients with a mean burn size of 33%. Eighty-three percent of these patients developed a neutrophil chemotactic defect at some time during their hospital stay. The results of this study indicated that the serum from burn patients did not contain cell-directed inhibitor(s) of chemotaxis (CDI) or chemotactic factor inactivator(s). Furthermore, the chemotactic defect in the burn patient's neutrophils could not be reversed by normal human serum, suggesting that the cause of this defect was not related to the absence of normal circulating humoral substances. Additionally, no suppressive effect of silvadene (10 g/ml) on neutrophil chemotaxis was found. Therefore, we concluded that stable serum factors were not likely to play a major role in the development of the acquired neutrophil defect thermal injury.     

Effects of simulated extracorporeal circulation on human leukocyte elastase release, superoxide generation, and procoagulant activity.

Activated leukocytes are thought to contribute to respiratory dysfunction, alterations in microvascular permeability, disseminated intravascular coagulation, and thrombosis, all of which can complicate extracorporeal circulation. The purpose of this work was to determine the effects of extracorporeal circulation on leukocyte functions likely to mediate organ damage. White blood cell counts in the bubble circuits (n = 5) fell to 51% +/- 7% (mean +/- standard error of the mean; p less than 0.05) of initial levels within 2 hours of recirculation. In contrast, counts from both the spiral coil (n = 5) and hollow-fiber (n = 5) groups remained at 91% +/- 12% and 100%, respectively. Plasma levels of human neutrophil elastase rose from 0.28 +/- 0.06 micrograms/ml to 3.14 +/- 0.36 micrograms/ml (p less than 0.05) and 0.20 +/- 0.02 micrograms/ml to 1.61 +/- 0.35 micrograms/ml (p less than 0.05) in bubble and spiral coil circuits, respectively, but from only 0.20 +/- 0.03 micrograms/ml to 0.96 +/- 0.42 micrograms/ml in the hollow-fiber circuit despite 2 hours of recirculation. Consistently, in response to N-formyl-L-methionyl-L-leucyl-L-phenylalanine, a chemotactic peptide, cells from spiral coil and bubble circuits released and generated significantly less elastase and superoxide anion, respectively. In contrast, neutrophils from the hollow-fiber circuits demonstrated enhancement of N-formyl-L-methionyl-L-leucyl-L-phenylalanine-induced elastase release and superoxide generation. Finally, mixed leukocytes from all circuits expressed procoagulant activity reaching statistical significance in bubble circuits. In conclusion, extracorporeal circulation has pronounced effects on neutrophil elastase release, superoxide anion generation, and leukocyte procoagulant activity. Spiral coil and bubble oxygenators cause granule release and, subsequently, reduced sensitivity to soluble agonists. In contrast, hollow-fiber oxygenators "prime" cells, actually enhancing reactivity. Recirculation through all circuits induces leukocyte procoagulant activity that is likely to contribute to surface-induced thromboses and excessive bleeding.     

C5a receptor modulation on neutrophils and monocytes from chronic hemodialysis and peritoneal dialysis patients

Chronic renal failure patients have an increased risk for infection which may partially be due to altered chemotactic ability of their white blood cells. This study was designed to evaluate chemotactic factor and Fc receptor expression on neutrophils (PMN) and monocytes from chronic renal failure patients on hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD). Analysis of these receptors was performed using flow cytometry and fluorescent chemotactic factors (C5a, f-Met-Leu-Phe-Lys [fMLPL] and casein) and heat-aggregated human IgG. Peripheral blood PMN and monocytes obtained from 14 HD patients (in the predialysis period) and 14 CAPD patients were analyzed for their ability to bind each of the fluoresceinated ligands. PMN and monocytes from both patient groups had a significant reduction in their ability to bind C5a. The average percentage (+/- s.e.m.) of PMN that bound C5a was 93.9 +/- 1.1 for the controls, 72.9 +/- 3.8 for HD patients, and 79.3 +/- 4.0 for CAPD patients. Similar results were obtained with monocytes with 69.7 +/- 1.9% for controls, 54.6 +/- 4.5% for HD patients, and 31.0 +/- 4.5% for CAPD patients. These differences in C5a binding were also reflected in the average intensity of fluorescence. There was no significant difference in the percentage or fluorescence intensity of PMN or monocytes that bound casein or aggregated IgG when either group of dialysis patients was compared to the control values. Binding of fMLPL by PMN and monocytes from the HD patients and PMN from the CAPD patients were similar to control values but the binding of fMLPL by monocytes from CAPD patients was significantly suppressed (p less than 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)