Serum myeloperoxidase and lactoferrin in neutropenia

The Rule of Histology in the Diagnosis of Periprosthetic Infection: Specific Granulocyte Counting Methods and New Immunohistologic Staining Techniques may Increase the Diagnostic Value

Objective:

The current study investigates the diagnostic accuracy of the criteria described for frozen sections and whether modern leukocyte specific staining techniques including leukocyte peroxidase and Naphtol-AS-D-chloroacetate-esterase will improve the accuracy of the intra-operative histology.

Method:

77 patients undergoing revision total hip and knee arthroplasty were included in this retrospective study. Patients were grouped into septic and aseptic based on intraoperative cultures. Tissue samples were analyzed utilizing the Mirra, Feldman, Lonner, Banit and Athanasou criteria.

Results:

An experienced pathologist had a high specificity (96%), but rather low sensitivity (57%) diagnosing infection. By using the Banit-, Mirra-, or Athanasou-criteria the sensitivity is increased to 0.90. The Feldman- and Lonner-criteria have a lower sensitivity (0.48 and 0.38), however, an increased specificity of 0.96 and 0.98, respectively. The Banit cut off has the highest accuracy (86%). MPOX and NACE staining increased the sensitivity and accuracy up to 100% and 92% respectively.

Conclusion:

Banit’s cut off is the most accurate histologic criteria to diagnose infection. Modern leukocyte specific staining techniques slightly improve the accuracy. The synovial fluid white blood cell count appears to be the most accurate intraoperative test.

Elevated fecal levels of eosinophil granule proteins predict collagenous colitis in patients referred to colonoscopy due to chronic non-bloody diarrhea

OBJECTIVE

Colonoscopy with biopsy sampling is often performed to detect collagenous colitis (CC) and lymphocytic colitis (LC) in patients with chronic non-bloody diarrhea. However, the diagnostic yield is low and incurs high costs. Fecal calprotectin (FC) and myeloperoxidase (MPO) indicate intestinal inflammation in ulcerative colitis (UC) and Crohn's disease (CD). In CC, elevated fecal levels of eosinophil protein X (EPX) and eosinophil cationic protein (ECP) have been reported. We aimed to evaluate if F-EPX, F-ECP, FC, and F-MPO could predict the diagnostic outcome in patients with chronic non-bloody diarrhea referred to colonoscopy. We also evaluated serum (S) EPX and ECP in this regard.

METHODS

Of 67 included patients, 63 (94%) underwent colonoscopy with biopsy sampling. Fecal EPX, F-ECP, FC, F-MPO, S-EPX, and S-ECP were analyzed.

RESULTS

Diagnostic outcome: normal: n = 46 (73%), CC: n = 9 (14%), LC: n = 4 (6%), UC: n = 2 (3%), CD: n = 2 (3%). Higher levels of F-EPX and F-ECP were found in CC compared to a normal diagnostic outcome (p = 0.01). No change was noted in any of the fecal markers in LC. When all of the fecal markers were normal the probability of a normal diagnostic outcome was 92%. We found no differences in S-EPX and S-ECP between the groups.

CONCLUSION

Elevated F-EPX and F-ECP could predict CC. None of the fecal markers predicted LC. Serum-EPX and S-ECP are not useful for the diagnosis of CC, LC, UC, or CD. With normal levels in all of the analyzed fecal markers, there is a low probability of a pathologic diagnostic outcome.

Fecal eosinophil cationic protein as a marker of active disease and treatment outcome in collagenous colitis: a pilot study

BACKGROUND AND AIMS

Fecal calprotectin (FC) is used as a marker for intestinal inflammation in inflammatory bowel disease (IBD) but there is no reliable marker for collagenous colitis (CC). We have previously demonstrated that the mucosal inflammation in CC is characterized by eosinophil activation, which is restored during budesonide treatment, but there is no enhanced neutrophil activity. The aim of this study was to evaluate the use of fecal eosinophil cationic protein (F-ECP) and eosinophil protein X (F-EPX) compared with the neutrophil-derived myeloperoxidase (F-MPO) and FC in patients treated for active CC.

METHODS

Patients with active CC (n = 12) were studied before and after 3, 7, 28 and 56 days of budesonide treatment. Clinical symptoms and stool frequency were recorded, fecal samples were collected, and F-ECP, F-EPX, F-MPO and FC were measured at each occasion.

RESULTS

All but one patient achieved remission. On inclusion 92%, 67%, 67% and 75% of the patients had elevated F-ECP, F-EPX, F-MPO and FC levels, respectively. All markers decreased during the treatment, particularly F-ECP and F-EPX, which decreased after only 3 days. At the end of the study 100%, 92%, 83% and 75% of the patients had normal F-ECP, F-EPX, F-MPO and FC values, respectively.

CONCLUSION

F-ECP demonstrated the best discriminating capacity in detecting active CC. A normalized F-ECP and F-EPX may further be studied as a marker for successful treatment. During budesonide treatment there is a rapid fall in F-ECP and F-EPX, accompanied by clinical improvement, indicating an essential role for the eosinophil participating in the pathophysiology of CC.

Blueberry husks, rye bran and multi-strain probiotics affect the severity of colitis induced by dextran sulphate sodium

OBJECTIVE

The enteric microbiota is a pivotal factor in the development of intestinal inflammation in humans but probiotics, dietary fibres and phytochemicals can have anti-inflammatory effects. The aim of this study was to evaluate the therapeutic effect of multi-strain probiotics and two conceivable prebiotics in an experimental colitis model.

MATERIAL AND METHODS

Sprague-Dawley rats were fed a fibre-free diet alone or in combination with Lactobacillus crispatus DSM 16743, L. gasseri DSM 16737 and Bifidobacterium infantis DSM 15158 and/or rye bran and blueberry husks. Colitis was induced by 5% dextran sulphate sodium (DSS) given by oro-gastric tube. Colitis severity, inflammatory markers, gut-load of lactobacilli and Enterobacteriaceae, bacterial translocation and formation of carboxylic acids (CAs) were analysed.

RESULTS

The disease activity index (DAI) was lower in all treatment groups. Viable counts of Enterobacteriaceae were reduced and correlated positively with colitis severity, while DAI was negatively correlated with several CAs, e.g. butyric acid. The addition of probiotics to blueberry husks lowered the level of caecal acetic acid and increased that of propionic acid, while rye bran in combination with probiotics increased caecal CA levels and decreased distal colonic levels. Blueberry husks with probiotics reduced the incidence of bacterial translocation to the liver, colonic levels of myeloperoxidase, malondialdehyde and serum interleukin-12. Acetic and butyric acids in colonic content correlated negatively to malondialdehyde.

CONCLUSIONS

A combination of probiotics and blueberry husks or rye bran enhanced the anti-inflammatory effects compared with probiotics or dietary fibres alone. These combinations can be used as a preventive or therapeutic approach to dietary amelioration of intestinal inflammation.

Lactoferrin in human neutrophilic polymorphonuclear leukocytes in relation to iron metabolism

Lactoferrin (LF), the iron-binding protein of external secretions and neutrophilic polymorphonuclear leukocytes (PMN), was studied in 27 patients during granulocytosis caused by acute inflammation and in disorders without granulocytosis (iron deficiency anemia, iron overload and liver diseases). During granulocytosis the LF concentration of PMN was significantly lower than in controls (p less than 0.001). This difference proved to be related to the number of PMN. A relation between the LF concentration of PMN and iron metabolism could be demonstrated: loss of iron by blood donation is accompanied by a significant decrease in the LF concentration in PMN, whereas iron therapy in patients with iron deficiency anemia is accompanied by a significant increase in the LF concentration in PMN.

Indices of inflammatory cell activity and pulmonary function in different stages of sarcoidosis

The present study was carried out to compare radiological and physiological changes in sarcoidosis with biochemical markers for inflammatory cell populations. Of 53 patients with sarcoidosis, 28 had respiratory symptoms and 30 past or present bilateral hilar adenopathy without symptoms. A clinical score based on lung function tests and radiological findings correlated well with elevations of lysozyme and beta2-microglobulin in serum, indicating increased inflammatory cell activity in patients with more severe lung affection. A covariation between beta2-microglobulin and lysozyme was found, suggesting concomitant activation of macrophages and lymphocytes in sarcoidosis. Serum levels of lactoferrin were elevated in patients with a disease of short duration but did not correlate with the severity of the lung affection. The closing volume also seems to be abnormal in the early course of the disease, while elevated lysozyme and beta2-microglobulin levels rather seem to reflect the extent of the pulmonary affection.

Purification of a 75 kDa protein from the organelle matrix of human neutrophils and identification as N-acetylglucosamine-6-sulphatase

A 75 kDa protein was purified to homogeneity from granule extracts of normal human granulocytes using Sephadex G-75 chromatography, Mono-S cation exchange chromatography and chromatofocusing. The protein consisted of one chain with a molecular mass of 75 kDa, as determined by SDS/PAGE. Tryptic peptide analysis by MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight) MS and sequence analysis by MS/MS identified the protein to be N-acetylglucosamine-6-sulphatase (EC 3.1.6.14). The identity of the protein was confirmed by demostrating enzymatic activity towards the substrate N-acetylglucosamine 6-sulphate. The enzyme was active over a broad pH range with an optimum of pH 7.0, and showed a K(m) value of 13.0 mM and a V(max) value of approximately 1.8 microM/min per mg. The enzyme also showed O-desulphation activity towards heparan sulphate-derived saccharides. Subcellular fractionation of neutrophil organelles showed the presence of enzymatic activity mainly in the same fractions as primary granules. Furthermore, PMA treatment of the neutrophils induced release of the enzyme, indicating its matrix protein nature. The presence of N-acetylglucosamine-6-sulphatase in human neutrophils implies that neutrophils may play a role in the modulation of cell surface molecules and extracellular matrix by O-desulphation.

Bronchial hyper-responsiveness predicts the development of mild clinical asthma within 2 yr in school children with hay-fever

In children with mild asthma, symptoms are not always apparent. Therefore, results of tests play an important role for the diagnosis. First, to investigate whether children with bronchial hyper-responsiveness (BHR) but no symptoms of asthma in 1992 had developed clinical asthma at follow up in 1994. The second aim was to find out the diagnostic properties of tests for asthma/allergic inflammation, using either doctor diagnosed asthma (DDA), self-assessed symptoms of asthma or iso-capnic hyperventilation of cold air (IHCA), as the standard, to diagnose asthma in a group of children with hay fever. Twenty-eight children with pollinosis, 12 of them with a history of asthma for the first time during the season 1992, were studied during the birch pollen season and in the autumn of 1994. During both periods, the bronchial hyper-reactivity was estimated by methacholine bronchial provocation tests (MBPT), bronchial variability by peak expiratory flow rate variability, subjective symptoms of asthma by visual analogue scale (VAS) and bronchial inflammation by serum and urine levels of inflammatory mediators. In 1994 IHCA was added during both seasons. Eight of 16 children with BHR but without clinical asthma in 1992 had developed asthma in 1994, 14 of 16 reacted to IHCA and 13 to MBPT. All 12 children with DDA in 1992 had still asthma in 1994 and 14 children with BHR in 1992 had persistent BHR in 1994. Of 23 children with BHR in 1992, 17 had DDA in 1994 and all maintained their BHR. Furthermore, 20 of them reacted to IHCA in 1994. In 1994, 24 of 28 hay-fever children had a positive IHCA tests and 24 had positive MBPT. In relation to VAS, the sensitivity of IHCA and MBPT to predict present asthma was high, but the specificity low, whereas the specificity of most other tests was high, but based on few individuals. In relation to DDA both the IHCA test (65-80%) and the MBPT test (79-85%) had a high sensitivity and it was three to six times more likely to find a positive test among asthmatics than in non-asthmatics. Children with hay fever without clinical asthma have a high risk of developing asthma within 2 yr. In relation to DDA, inhalation of cold air and the MBPT showed a high sensitivity.

Subcellular localization and mobilization of carcinoembryonic antigen-related cell adhesion molecule 8 in human neutrophils

The subcellular localization and mobilization of carcinoembryonic antigen-related cell adhesion molecule 8 (CEACAM8) was investigated quantitatively in human neutrophils. In resting neutrophils the majority of CEACAM8 was present in the secondary granules, and a small amount of CEACAM8 was present in a light membrane fraction. Stimulation of the neutrophils with phorbol 12-myristate 13-acetate caused a dramatic increase in the content of CEACAM8 in the light membrane fraction, suggesting a translocation of CEACAM8 to the plasma membrane from intracellular pools. The cellular content of CEACAM8 in the neutrophils was estimated to be 82.4 +/- 8.9 ng/10(6) cells (mean +/- SE, n = 10). Administration of granulocyte colony-stimulating factor (G-CSF) to healthy individuals resulted in an increased content of CEACAM8 in neutrophils on day 1, which decreased on day 4. However, the content of CEACAM8 in the light membrane fraction was increased on day 4, possibly due to the stimulation by induced secondary cytokines, such as tumour necrosis factor-alpha (TNF-alpha). This study establishes the secondary granules as the major intracellular pools of CEACAM8 in human neutrophils, from which it may translocate to the plasma membranes upon stimulation of the cells. The translocation of CEACAM8 seen in vivo after G-CSF administration is probably indirect and caused by cytokines such as TNF-alpha.

Persorption of bovine lactoferrin from the intestinal lumen into the systemic circulation via the portal vein and the mesenteric lymphatics in growing pigs

The absorption and the transportation of intestinally administrated bovine lactoferrin (LF) were immunohistochemically and physiochemically investigated in the small intestine of growing pigs. At the apical halves of the small intestinal villi, bovine LF was absorbed by transcytosis as small vesicles through villous columnar epithelial cells. The presence of bovine LF-positive membranes of transcytotic vesicles suggests that the absorption was mediated by LF-binding factors on the epithelial cell membranes. Almost all of the absorbed bovine LF was demonstrated to be transported via the lymphatics and the portal vein into the systemic circulation. The LF-concentration in systemic circulation was significantly higher at 1 hr following intestinal administration of bovine LF. Bovine LF-positive lymphocytes also were transferred into the systemic circulation from intestine via the lymphatics and the portal vein.

Dose-response trial of lactoferrin in patients with chronic hepatitis C

Hepatitis C virus (HCV) is one of the most common causes of chronic hepatitis. Interferon is presently the only effective treatment for chronic hepatitis C (CH-C), though its effectiveness is limited. Lactoferrin (LF), which is an 80-kDa, iron-binding glycoprotein, has several biological activities including anti-viral activity, and it was recently reported to inhibit HCV infection in cultured human hepatocytes. The present trial was designed to assess the relationship between the dose of bovine LF (bLF) and the effect of bLF on serum alanine aminotransaminase (ALT) and HCV RNA levels in patients with CH-C. Forty-five patients entered at each of the three dose levels (bLF of 1.8, 3.6, and 7.2 g/day) received orally an 8-week course of bLF. There was no significant relation between the dose of bLF and the effect of bLF on serum ALT or HCV RNA levels. Biochemical (a 50% or greater decrease in the serum ALT level) and virological (a 50% or greater decrease in HCV RNA level) responses were observed in two and four patients, respectively, but all responders relapsed during the follow-up period after bLF treatment. The bLF treatment was generally well tolerated, and no patient had any serious adverse event. In conclusion, the excellent tolerance and potential anti-HCV activity of bLF shown in this trial suggest that further trials using a large number of patients are mandatory. We are currently conducting a double-blind randomized controlled trial comparing bLF with placebo to clarify the anti-HCV activity of bLF in patients with CH-C.

Degranulation of primary and secondary granules in adherent human neutrophils

The aim of this study was to investigate whether neutrophil adhesion to extracellular matrix proteins like fibronectin, fibrinogen, and albumin influence the release proteins from primary and secondary granules of neutrophils stimulated by phorbol-myristate-acetate (PMA) and formyl-methionyl-leucyl-phenylalanine (f-MLP). Isolated granulocytes plated on wells coated with fibronectin, fibrinogen, and albumin were stimulated with f-MLP (10-7 mol/l), PMA (10-9 mol/l), Mn2+ (5 mmol/l), or combinations of these stimuli, and the degree of adhesion to protein-coated surfaces and the amount of granule proteins released was quantified during 90 min of incubation. PMA, in combination with Mn2+, induced a maximum release of approximately 80% of the intracellular content of lactoferrin and human neutrophil lipocalin (HNL) and 15-20% of the myeloperoxidase (MPO) content regardless of the protein used. PMA or f-MLP alone induced 30-40% release of lactoferrin and HNL depending on the protein that the cells were plated on. Adhesion and release of lactoferrin and HNL were quantitatively related when induced by PMA and PMA plus Mn2+, but not by f-MLP. The mean release of lactoferrin and HNL showed a significant negative relationship to the viability of the cells. In conclusion, adhesion modulates neutrophil degranulation, but it is not always quantitatively related or related in time.

Seasonal differences of peak expiratory flow rate variability and mediators of allergic inflammation in non-atopic adolescents

Variations in peak expiratory flow (PEF) and serum eosinophil mediators were studied in healthy adolescents. Twenty-five boys and 31 girls, 11-16 years of age (mean age 14.3 years), were selected and investigated during the birch pollen season of 1995; 45 were also investigated during the autumn of the same year. The PEF was measured twice daily and eosinophil mediators in serum and in urine were measured by radioimmunoassay (RIA) once during the birch pollen season and once in autumn. The type values of the daily PEF variation, expressed in amplitude percentage mean, were 6.4 and 3.9%, mean values were 7.35 and 6.74%, and the 95th percentiles were 18 and 14%, during the birch pollen season and autumn, respectively. The 95th percentiles were 41 and 38 microg/l for serum eosinophil cationic protein (s-ECP), 74 and 62 microg/l for serum eosinophil protein X (s-EPX), 987 and 569 microg/l for serum myeloperoxidase (s-MPO), and 165 and 104 microg/mmol for urinary eosinophil protein X/urinary creatinine (u-EPX/u-creatinine), during the birch pollen season and autumn, respectively. The levels of the eosinophil mediators decreased significantly from May (n = 56) to November (n = 45), for s-ECP from a median value of 14 microg/l to 7 microg/l (p= 0.001), for s-EPX from a median value of 28 microg/l to 20 microg/l (p= 0.001), and for the neutrophil mediator, s-MPO, from a median value of 440 g/l to 292 g/l (p< 0.001). The PEF variability decreased significantly (p= 0.037), from spring (n = 55; median 8%, 95% confidence interval [CI] 7.8-10.19) to autumn (n = 44; median 6%, 95% CI 6.1-8.9). A significant correlation was found between the levels of s-ECP and s-EPX (rs = 0.7, p< 0.001), between s-ECP and s-MPO (rs = 0.6, p< 0.001), between s-EPX and s-MPO (rs = 0.4, p< 0.005), and between s-EPX and u-EPX/u-creatinine (rs = 0.6, p< 0.0001), in the birch pollen season (n = 56) and in the autumn (n = 45). There was a positive correlation found in PEF variability between the two seasons (n = 43; rs = 0.5, p= 0.0006). No other correlation was found between PEF variability and any other parameters. The difference in the levels of eosinophil mediators between seasons in non-atopic, healthy children is unexplained. Normal limits for mediators were higher and PEF variability was almost the same as has been reported in adults. When using normal values, seasonal influences should be considered.

Human neutrophil lipocalin (HNL) and myeloperoxidase (MPO). Studies of lung lavage fluid and lung tissue

Myeloperoxidase (MPO) and human neutrophil lipocalin (HNL) are proteins which are stored in neutrophil granulocytes, in the primary and secondary granules, respectively. These granules or their contents of MPO and HNL are secreted upon activation of the cells, and measurement of these soluble markers in biological fluids, such as bronchoalveolar lavage (BAL), has been proposed to mirror the degree of neutrophil activity in the tissue. We conducted a BAL study in 10 healthy volunteers, with the aim to evaluate the intra-individual variability of the concentration of HNL and MPO recovered in sequential aspirations, during a time period when the concentrations of HNL and MPO in BAL fluids were considered to have equilibrated with those in the underlying tissues. The concentrations of HNL were less variable than those of MPO (coefficients of variability 0.33 +/- 0.07 vs. 0.92 +/- 0.28; P = 0.01), suggesting HNL to be a more useful marker of neutrophil activity within the airspace. The specificity of HNL as a selective index of neutrophil cells was confirmed by means of immunohistochemical staining of uninvolved lung tissue specimens obtained from patients referred to pulmonectomy due to carcinoma. While HNL was located only to intracellular spaces of neutrophils, MPO was in addition located to other cells as well. We speculate that the dynamic changes of pressure across the membranes and flow of solutes during a lavage process might mobilize particulate matter and adherent cells, some of which may be loaded with MPO, and that this may introduce larger variability in the recovery of MPO than of HNL. We conclude that using HNL as a soluble indicator of neutrophil presence is more feasible than using MPO.

Methods for quantitation of human neutrophil proteins, a survey

Neutrophils contain a variety of proteins that endow the cell with its capacity to migrate towards and eliminate microbial pathogens. Many of these proteins are largely or exclusively localized to neutrophils. It is therefore of interest to quantitate these proteins in a variety of clinical settings as well as in basic research. The aim of this survey is to give an introduction to some of the more commonly used methods for quantitation of neutrophil proteins and to discuss advantages and problems of the different methods and the relevance of quantitating neutrophil proteins in different biological settings.

Serum lysozyme: a potential marker of monocyte/macrophage activity in rheumatoid arthritis

OBJECTIVE

Estimate the contribution of monocytes/macrophages to the disease process in rheumatoid arthritis (RA), by measuring the serum levels of the leucocyte-derived granular proteins: lysozyme, myeloperoxidase (MPO), lactoferrin and human neutrophil lipocalin (HNL).

METHODS

Serum levels of these granular proteins were measured in patients with RA (n=23) and in healthy controls (n=27), and in 10 patients with RA after treatment with low-dose prednisolone. The serum levels of the granular proteins were also measured before and after treatment with metyrapone, a substance that inhibits the synthesis of cortisol in the adrenals.

RESULTS

The serum levels of lysozyme and MPO were elevated in patients with RA, while the concentrations of lactoferrin and HNL were similar in both groups. Prednisolone treatment decreased the serum concentration of lysozyme and MPO. Metyrapone did not influence the level of the granular proteins measured.

CONCLUSIONS

The increased serum levels of lysozyme and MPO, but not of HNL and lactoferrin in RA could indicate a stimulated secretory activity of mononuclear phagocytes. The measurement of serum lysozyme, as an indicator of monocyte/macrophage activity, might be used to study disease activity in RA.

Adherence to endothelial cells induces release of soluble tumor necrosis factor (TNF) receptor forms from neutrophil granulocytes

The TNF receptors, TNF-R55 and TNF-R75, may undergo proteolytic cleavage and form soluble receptor forms, TNF-R55-BP and TNF-R75-BP. Neutrophils are abundant with both forms of TNF-receptors, while endothelial cells (ECV 304) only express TNF-R55. Human neutrophils were allowed to interact with an unstimulated or a IL-1 beta stimulated endothelium followed by determination of TNF-R75-BP with ELISA. Neutrophils in suspension or in contact with an unstimulated endothelium released only low amounts of TNF-R75-BP. However, neutrophils released significant amounts of TNF-R75-BP after adherence to an endothelium stimulated with IL-1 beta. Neutrophils were not generally activated during adherence since concomitant release of lactoferrin from neutrophils only reached levels of 1-5% compared with incubation with phorbolesters. Blocking integrins with antibodies to CD11/CD18 resulted in inhibition of both neutrophil adherence to an endothelium and shedding of TNF-R75. In addition, TNF-R55-BP decreased the production of TNF from IL-1 beta stimulated endothelial cells, suggesting that soluble TNF receptor forms are able to inhibit TNF production.

Effects of heparin coating on the expression of CD11b, CD11c and CD62L by leucocytes in extracorporeal circulation in vitro

Leucocyte adhesion molecules are involved in the leucocyte-endothelial interaction and in the activation of coagulation and binding of complement and endotoxin. Thus, they are important in inflammation, systemic acute phase reaction, ischaemia reperfusion injury and resistance against infections. The expression of the adhesion molecules CD11b, CD11c and CD62L on leucocytes and changes in plasma products of neutrophil activation (myeloperoxidase, lactoferrin) and complement activation (C3bc, SC5b-9 (TCC)) were examined in an extracorporeal circulation (ECC) model and the effects of Carmeda bioactive surface (CBAS) heparin coating (n = 7) of the circuits were compared to uncoated control circuits (n = 5). In this model, new 'unactivated' cells mobilized from the bone marrow could not interfere with descriptive measures of cell activation as seen in in vivo studies. In the control group, CD11b and CD11c were upregulated on monocytes and granulocytes during ECC, whereas CD62L was downregulated. Heparin coating reduced the increase in CD11b and CD11c on granulocytes (p < 0.02 at 2 h), but the delayed increase in CD11c on monocytes and the delayed downregulation of CD62L on granulocytes and monocytes did not reach statistical significance. Further, heparin coating also reduced the initial decrease in the absolute cell counts of monocytes and granulocytes (p = 0.01 at 2 h), reflecting reduced adhesion to the oxygenator/tubing. The increases in plasma myeloperoxidase, lactoferrin, C3bc and TCC were lower in the heparin-coated group compared to the control group. The increases in plasma myeloperoxidase and lactoferrin correlated significantly to the increase in CD11b (r = 0.71, p = 0.02 and r = 0.64, p = 0.05, respectively) and CD11c (r = 0.72, p = 0.008 and r = 0.72, p = 0.008, respectively) on granulocytes, suggesting interacting regulatory pathways in the process of neutrophil adhesion, activation and degranulation. Thus, in this in vitro ECC model, heparin coating of oxygenator/tubing sets reduced leucocyte activation and leucocyte adhesion-related phenomena.

Immunological responses to respiratory syncytial virus infection in infancy

OBJECTIVES

To determine whether there is evidence of immunological responses in infants with respiratory syncytial virus (RSV) bronchiolitis by measuring inflammatory mediators in peripheral blood and, if found, whether these related to the severity of illness.

PATIENTS AND METHODS

Blood was taken from 94 children with RSV infection during the acute episode and 10 or more days later when the child was well. Control serum samples were obtained from well children of similar ages. Serum samples were assayed for mediators of lymphocyte activity (interleukin-4 (IL-4), soluble interleukin-2 receptor (sCD25), soluble intercellular adhesion molecule-1 (sICAM-1), eosinophil activity (eosinophil cationic protein) and neutrophil activity (myeloperoxidase). Symptoms were assessed as very mild (coryza only), mild (symptoms of lower respiratory tract infection), moderate (requiring nasogastric or intravenous fluids), and severe (requiring oxygen or ventilation).

RESULTS

IL-4 concentrations were at the lower limits of detection of the assay. The concentrations of sCD-25 were greater in samples from patients with acute illness than from convalescent patients and both were greater than in control samples. sICAM-1 concentrations were similar in samples from patients with acute illness and convalescent patients, but both were greater than in samples from controls. Eosinophil cationic protein concentrations were lower in samples from patients with acute illness than in those from convalescent patients; there was no difference between samples from convalescent and control patients. Myeloperoxidase concentrations were similar in all samples. There was no correlation between the severity of infection and the concentrations of any inflammatory mediators.

CONCLUSIONS

There is evidence of an inflammatory response in the peripheral blood of infants with acute bronchiolitis which may affect lymphocytes and eosinophils, but an association between this response and the severity of illness was not shown here.

Attenuation of changes in leukocyte surface markers and complement activation with heparin-coated cardiopulmonary bypass

BACKGROUND

The inflammatory response induced by cardiopulmonary bypass can result in severe organ dysfunction in some patients. This postperfusion response is caused mainly by contact between blood and the foreign surface of the cardiopulmonary bypass equipment and includes adhesion of leukocytes to vascular endothelium, which precedes a series of events that mediate inflammatory damage to tissues.

METHODS

Low-risk patients accepted for coronary artery bypass grafting were randomized to operation with the cardiopulmonary bypass surface either completely heparin coated (Duraflo II) or uncoated. There were 12 patients in each group. Blood plasma sampled during cardiopulmonary bypass was analyzed for complement activation (C3bc and terminal SC5b-9 complement complex) and neutrophil activation (lactoferrin and myeloperoxidase). In addition, neutrophils, monocytes, and platelets were counted, and the expression of surface markers on the neutrophils and monocytes (complement receptor [CR] 1, CR3, CR4, and L-selectin) and on the platelets (P-selectin and CD41) was quantified with flow cytometry.

RESULTS

Clinical and surgical results were similar in both groups. In the group with the heparin-coated surface, the formation of the terminal SC5b-9 complement complex was significantly reduced, and the counts of circulating leukocytes and platelets were significantly less reduced initially but were higher at the end of cardiopulmonary bypass compared with baseline. Also, the expression of CR1, CR3, and CR4 was significantly less upregulated and the L-selectin, significantly less downregulated on monocytes and neutrophils.

CONCLUSIONS

We conclude that heparin coating reduces complement activation and attenuates the leukocyte integrin and selectin response that occurs when uncoated circuits are used.

Relationship between disease severity and inflammatory markers in cystic fibrosis

To evaluate the clinical use of measuring neutrophil, lymphocyte, and eosinophil activities, serum myeloperoxidase (MPO), soluble interleukin-2 receptors (sIL-2R), and eosinophil cationic protein (ECP) were measured in 98 patients with cystic fibrosis and in 85 healthy children. Serum concentrations of MPO, sIL-2R, and ECP were increased in patients with cystic fibrosis (median 807 micrograms/l, 4452 pg/ml, 48.8 micrograms/l, respectively) compared with the controls (median 319 micrograms/l, 2743 pg/ml, 9.4 micrograms/l). ECP concentrations, but not serum MPO or sIL-2R, were significantly related to disease severity assessed by the Shwachman-Kulczycki score and by pulmonary function (forced expiratory volume in one second % predicted). Neither ECP nor sIL-2R was influenced by Pseudomonas aeruginosa infection, acute pulmonary exacerbation, or atopy. Serum MPO, however, was strongly correlated with acute pulmonary exacerbation. In the light of these findings the measurement of serum ECP might thus be used for clinical monitoring and for assessing disease severity in cystic fibrosis. The measurement of serum MPO and sIL-2R did not correlate with the disease severity.

Centrifugal pump and heparin coating improves cardiopulmonary bypass biocompatibility

BACKGROUND

Centrifugal pumps are being used increasingly for short-term extracorporeal circulation purposes such as during heart operations. Whether the centrifugal pump improves the cardiopulmonary bypass biocompatibility has not been fully documented.

METHODS

A roller pump (n = 20) was compared in vivo with a centrifugal pump (n = 20) in groups of patients in which cardiopulmonary bypass circuits that were either totally heparin coated (Carmeda BioActive Surface; n = 20) or uncoated (n = 20) were used. We expected the heparin coating to attenuate blood activation, thus possibly making the comparison of the two pumps easier with respect to their different blood activation potentials. Samples of blood plasma, obtained during cardiopulmonary bypass from low-risk coronary artery bypass grafting patients, were analyzed for hemolysis (plasma haemoglobin), complement activation (C3bc and the terminal complement complex), a complement lytic inhibitor (vitronectin), coagulation activation (fibrinopeptide A), granulocyte activation (lactoferrin), and platelet activation (beta-thromboglobulin).

RESULTS

The concentrations of terminal complement complex, lactoferrin, and beta-thromboglobulin were significantly lower in association with heparin-coated surfaces. The concentration of plasma hemoglobin was significantly lower in association with the centrifugal pump. In uncoated circuits, the beta-thromboglobulin level was significantly higher in association with the roller pump than with the centrifugal pump, but this significant reduction in the beta-thromboglobulin level did not hold true for the heparin-coated circuit group.

CONCLUSIONS

A heparin-coated cardiopulmonary bypass surface reduces the blood activation potential during cardiopulmonary bypass, and the centrifugal pump causes less hemolysis than the roller pump.

Differences in blood activation related to roller/centrifugal pumps and heparin-coated/uncoated surfaces in a cardiopulmonary bypass model circuit

An in vitro model cardiopulmonary bypass (CPB) circuit consisting ot tubing, oxygenator and venous reservoirs with either a roller or a centrifugal pump, and with either heparin-coated (Carmeda Bioactive Surface, CBAS) or uncoated surfaces, was studied with respect to 'blood activation', using small-scale-based blood volume (450 + 500 ml). Sixteen circuits were tested in each pump group, eight with and eight without heparin-coated surfaces, by circulating heparinized fresh human blood for 72 hours at 30 degrees C. Blood plasma, sampled at defined intervals, was analysed for haemolysis (lactate dehydrogenase and potassium), complement activation (C3bc and C5b-9 (TCC)), complement lytic inhibitors (vitronectin and clusterin), coagulation activation (fibrinopeptide A), granulocyte (lactoferrin and myeloperoxidase) and platelet (beta-thromboglobulin) activation and contaminating endotoxin. The heparin coating significantly reduced the concentrations of C3bc, TCC, fibrinopeptide A, lactoferrin, myeloperoxidase and beta-thromboglobulin. The two pump types did not differ with respect to these parameters, but the roller pump caused significantly higher increases in plasma LDH and potassium and significantly greater reductions in clusterin and vitronectin than the centrifugal pump. Endotoxin concentration was low at the start and after 24 hours in all groups. These results confirm that heparin-coated CPB surfaces reduce blood activation, and suggest that centrifugal pumps cause less haemolysis and less reduction in lytic complement inhibitors than roller pumps.

High and low heparin dose with heparin-coated cardiopulmonary bypass: activation of complement and granulocytes

BACKGROUND

Cardiopulmonary bypass with heparin-coated circuits allows reduced amounts of systemic heparin. Heparin inhibits activation of the complement cascade experimentally, but the effects of different levels of systemic heparin on activation of complement and granulocytes in patients have remained unknown.

METHODS

Fifty-two patients undergoing coronary artery bypass procedures were studied. Cardiopulmonary bypass circuits completely coated with surface-bound heparin were used for one group given low-dose heparin (n = 17) (activated clotting time > 250 seconds), and was compared with a second group having normal high-dose heparin (activated clotting time > 480 seconds) (n = 18). A third control group was perfused with ordinary uncoated circuits and a full heparin dose (n = 17).

RESULTS

During cardiopulmonary bypass, the C3 activation products C3b, iC3b, and C3c increased markedly in all three groups compared with baseline, but significantly less in the two heparin-coated groups (high dose, median maximal increase 58 arbitrary units (AU)/mL; low dose, 48 AU/mL) compared with the uncoated control group (74 AU/mL) (p < 0.01). The difference between the two coated groups was not significant. Similarly, the maximal increase in terminal SC5b-9 complement complex was considerably lower in the heparin-coated groups (high dose, 2.5 AU/mL; low dose, 2.6 AU/mL) compared with the level observed in the uncoated control group (5.3 AU/mL) (p < 0.01). The release of the granulocyte activation enzymes myeloperoxidase and lactoferrin increased from the beginning of the operation, with peak levels at the end of cardiopulmonary bypass (p < 0.01). The concentration of lactoferrin was significantly (p < 0.01) reduced in the low heparin dose group compared with the two other groups receiving normal high heparin doses, indicating that circulating heparin is an important granulocyte agonist, acting independently of the presence or absence of heparin-coated surfaces. Also for myeloperoxidase a higher level was observed in the high heparin dose group.

CONCLUSIONS

Complement activation was significantly reduced in both heparin-coated groups and was independent of the level of systemic heparinization, whereas granulocyte activation was reduced only in patients who received low doses of systemically administered heparin. The results indicate that a moderate reduction of the systemic heparin dose may be an advantage with regard to improved biocompatibility when using heparin-coated cardiopulmonary bypass circuits.

Complement and granulocyte activation in two different types of heparinized extracorporeal circuits

Complement and granulocyte activation were studied in cardiopulmonary bypass circuits completely coated with either end-attached covalent-bonded heparin, the Carmeda BioActive Surface, or with the Duraflo II bonded heparin, in combination with reduced systemic heparinization (activated clotting time > 250 seconds). The control groups were perfused with uncoated circuits and full heparin dose (activated clotting time > 480 seconds). Altogether 67 patients undergoing elective first-time myocardial revascularization were investigated, having extracorporeal perfusion with a Duraflo II coated circuit (n = 17), an identical but uncoated circuit (n = 17), a Carmeda coated circuit (n = 17), or an equivalent uncoated circuit (n = 16). During cardiopulmonary bypass, the C3 activation products C3b, iC3b, and C3c (C3bc) and the terminal SC5b-9 complemented complex increased markedly in all four groups compared with baseline, but significantly less in the two coated groups than in their control groups. Additionally, a significantly lower concentration of C3bc was observed in the Carmeda coated group, with maximal increase of median 28 AU/ml compared with 50 AU/ml in the Duraflo II coated group (p = 0.003). Similarly, in the Carmeda coated group, the maximal increase of terminal complement complex was considerably lower (0.8 AU/ml) than the levels recognized in the Duraflo II coated group (2.4 AU/ml) (p < 0.001). The release of the granulocyte activation myeloperoxidase and lactoferrin increased from the beginning of the operation, with peak levels at the end of bypass. A significant reduction of lactoferrin release was recognized when comparing the coated groups with the control groups. The difference between the two coated groups (Carmeda 228 micrograms/L; Duraflo II 332 micrograms/L; p = 0.05) was marginally significant. For myeloperoxidase, no significant differences were observed between the coated and uncoated groups. In conclusion, both types of heparin-coated circuits reduced complement activation and release of lactoferrin, but the Carmeda circuit proved to be more effective than the Duraflo II equipment.

Disparity in blood activation by two different heparin-coated cardiopulmonary bypass systems

BACKGROUND

Several studies have indicated reduced "blood activation" in heparin-coated cardiopulmonary bypass systems. The present study compares the effect of two different heparin coatings on different blood activation indices.

METHODS

Low-risk patients (n = 40) were randomized to coronary artery bypass grafting using cardiopulmonary bypass with surfaces coated entirely by either the Duraflo II heparin coat or the Carmeda Biological Active Surface, or with identical uncoated equipment. In all cases, a standard systemic heparin dosage was used. Complement activation (C3 activation products C3bc and C3a and formation of fluid phase terminal SC5b-9 complement complex), neutrophil activation (lactoferrin and myeloperoxidase), and lytic inhibitors (vitronectin and clusterin) were quantified during cardiopulmonary bypass and 6 hours postoperatively.

RESULTS

Heparin coating by either method reduced the formation of terminal SC5b-9 complement complex and the release of lactoferrin and myeloperoxidase compared with uncoated systems. Lactoferrin and myeloperoxidase levels increased significantly during cardiopulmonary bypass in the Duraflo II group, whereas no significant increase was observed in the Carmeda Biological Active Surface group. The least formation of terminal SC5b-9 complement complex and neutrophil activation was observed with the Maxima Carmeda Biological Active Surface-coated equipment. The vitronectin and clusterin concentrations were significantly less reduced in the Duraflo II compared with the control group. This study underlines the importance of terminal SC5b-9 complement complex as a suitable marker in the evaluation of complement activation during cardiopulmonary bypass.

CONCLUSIONS

Both heparin coatings reduce blood activation, probably more so with Carmeda Biological Active Surface than with Duraflo II.

The differential release of eosinophil granule proteins. Studies on patients with acute bacterial and viral infections

BACKGROUND

Earlier in vitro studies have suggested that the eosinophil may release its granule proteins selectively depending on the stimulus to which the cell is exposed.

OBJECTIVE

The object of the present study was to study the question of selective release in vivo by means of serum measurements of the two eosinophil granule proteins eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) in acute infections.

METHODS

Fourty-six subjects with acute infections were studied before treatment, 20 with bacterial infections and 26 with viral infections. Serum ECP, EPO and MPO were measured by specific RIA.

RESULTS

In acute bacterial infections ECP, but not EPO, was significantly raised in serum (P < 0.0001) compared with non-infected healthy subjects. In acute bacterial infections ECP was significantly correlated to the levels of the neutrophil marker myeloperoxidase (MPO) (rs = 0.96, P < 0.0001) but not to EPO. In acute viral infections neither ECP nor EPO were on average raised. However, almost 20% the patients had elevated levels of bot proteins. In the viral infections the serum-levels of ECP and EPO were correlated (rs = 0.63, P < 0.001), but no correlation was found with MPO.

CONCLUSION

It is concluded that eosinophils are activated during acute bacterial infections and that this activation results in the preferential mobilisation of ECP. The simultaneous assay of the two eosinophil proteins, ECP and EPO, may give new insight into the role of the eosinophil in disease.

Eosinophil cationic protein in nasal secretion and in serum and myeloperoxidase in serum in respiratory syncytial virus bronchiolitis: relation to asthma and atopy

Eosinophil cationic protein (ECP) in nasal secretions was determined in 34 infants with respiratory syncytial virus (RSV) bronchiolitis during the acute infection stage and one and six months later. ECP in serum was determined in 19 of these children at the same time. Myeloperoxidase (MPO) was determined in the same 19 children at the acute infection stage and after one month. All children were followed prospectively for two years after the infection with regard to the development of bronchial obstructive symptoms. Asthma, defined as three or more episodes of bronchial obstruction verified by a physician, developed in 18% of children and less severe obstructive symptoms in 29%. A screening test for food IgE antibodies in serum was performed six months and a skin prick test two years after the acute infection. Nasal ECP/albumin ratios after six months were significantly higher than during the acute RSV infection. MPO, but not ECP, levels in serum were significantly elevated at the time of acute infection compared with levels after one month. Nasal ECP/albumin ratios at the acute infection were compared to a control group of 27 infants with non-RSV upper respiratory tract infections and did not differ. It was not possible to predict, either from ECP/albumin ratios in nasal secretion or from ECP and MPO in serum, which children would develop asthma, other bronchial obstructive symptoms or positive IgE tests.

Serum levels of granulocyte-colony stimulating factor (G-CSF) in bacterial and viral infections, and in atypical pneumonia

Serum granulocyte-colony stimulating factor (G-CSF) was measured with an ELISA method in patients with acute bacterial and viral infections, or with an atypical pneumonia. Before initiation of antibiotic treatment, G-CSF was found to be significantly increased (799 +/- 1501 ng/l) in sera from 34 patients with an acute bacterial infection compared with the 27 patients with a viral infection (58 +/- 34 ng/l; P < 0.001) and with the eight patients with an atypical pneumonia (60 +/- 33) ng/l; P < 0.001). No significant difference in G-CSF levels was seen between gram-positive and gram-negative bacterial infections. In septic shock, increased G-CSF levels were seen both in patients with leucocytosis and leucopenia. In uncomplicated bacterial infections, both G-CSF and IL-6 were increased on day 0, and decreased rapidly after initiation of antibacterial therapy and before the patients became afebrile. In bacterial infections on day 0, G-CSF levels correlated with mononuclear cells (rs = -0.62, P < 0.001), IL-6 (rs = 0.40, P < 0.05) and S-MPO (rs = -0.5, P < 0.01). In viral infections, G-CSF was correlated with mononuclear cells (rs = 0.41, P < 0.05), white blood cell counts (rs = 0.56, P < 0.01), neutrophils (rs = 0.41, P < 0.05) and CRP (rs = 0.47, P < 0.05). We conclude that G-CSF is rapidly raised in the blood in acute bacterial infections but not in acute viral infections or in infections with Mycoplasma pneumonia. Our results also support the theory that G-CSF is involved in the mechanisms of mobilization of neutrophils into the peripheral circulation.

Purification and characterization of a human neutrophil lipocalin (HNL) from the secondary granules of human neutrophils

A 45 kDa-protein was purified from the granules of human neutrophils. The protein consists of two apparently identical subunits. The isoelectric point was pH 8.40, and the molecular weight 45 kDa (unreduced) or 24 kDa (reduced). Treatment of the protein with Endoglucosidase F resulted in a reduction in the molecular weight to 20 kDa, indicating the presence of N-linked carbohydrate. The extinction coeffient was E1%,1cm = 13.76 at 280 nm. The 60 amino acid sequence revealed up to 65% sequence homology with rat alpha 2-microglobulin-related protein, which belongs to the lipocalin family. The protein co-sedimented with secondary (specific) granule marker proteins and correlated to the neutrophil content of Lactoferrin (r = 0.81, p < 0.001) and was estimated to be 0.59 microgram 10(-6) cells. Release studies showed that the neutrophils released 51.4 +/- 9.0% of the total cellular content of the protein when they were exposed to serum-opsonized particles, which was much higher than the release of Myeloperoxidase (12.7 +/- 3.5%) and Lactoferrin (22.9 +/- 4.7%). The N-terminal and four tryptic fragment amino acid sequence of the protein was identical with an N-formyl peptide binding 24 kDa protein and gelatinase associated protein of human neutrophils. In conclusion, we have purified and characterized a protein, human neutrophil lipocalin (HNL), from the secondary granules of human neutrophils and shown that it is readily mobilized from the neutrophils upon stimulation.

The effect of rGM-CSF on neutrophil and eosinophil regeneration after ABMT as monitored by circulating levels of granule proteins

In order to further evaluate the effects of rGM-CSF on the reconstituting granulopoiesis, plasma and serum levels of myeloperoxidase (MPO) and lactoferrin (LF), as well as serum levels of eosinophil cationic protein (ECP), were monitored daily during a period of 3-4 weeks following ABMT in a group of 22 patients treated with either rGM-CSF (n = 11) or placebo (n = 11). Despite faster increase in the neutrophil counts in the rGM-CSF group, we did not observe any difference either in P-MPO or in P-LF during the period of early engraftment (days 11-19). This finding indicates that the proliferative effect of rGM-CSF on the neutropoiesis may be overestimated when neutrophil counts alone are taken into consideration, and suggests that other mechanisms may have contributed to the increase in the number of circulating neutrophils. The ratio of the serum to plasma level of LF, but not of MPO, was higher in the rGM-CSF group, probably reflecting a specific in vivo neutrophil priming effect. In the rGM-CSF group there was a clear increase of S-ECP during the second and third week post transplant, corresponding to an increase in eosinophil counts, which indicates that rGM-CSF stimulated eosinophil reconstitution without causing excessive activation of the mature eosinophils.

Releasability of human hypereosinophilic eosinophils is related to the density of the cells

The activity of eosinophils and neutrophils with respect to the release of granule proteins was studied in 11 patients with the hypereosinophilic syndrome (HES). Granulocytes or purified eosinophils were stimulated with serumopsonized Sephadex particles (C3b-induced release), and the released amounts of eosinophil cationic protein (ECP), eosinophils protein-X (EPX) and myeloperoxidase (MPO) were measured by means of specific radioimmunoassays (RIA). Eosinophils obtained from patients with HES released significantly more ECP (P < 0.002) and EPX (P < 0.01) after 20 min of incubation than cells from the control group. The cellular content of ECP and EPX in eosinophils obtained from the patients with HES was significantly reduced to 50% and 62%, respectively, of the content of these granule proteins of eosinophils from the control group. In separated eosinophils light-density eosinophils released more of both ECP and EPX than normal density eosinophils. There was no difference in MPO release between the patients and the control group. We conclude that the eosinophils from patients with HES have an increased propensity to release their granule proteins and the releasability seems to be related to the density of the cells.

Influence of allergen avoidance at high altitude on serum markers of eosinophil activation in children with allergic asthma

A cohort of 12 asthmatic children was followed over several months, during which they moved back and forth from an allergen-free to an allergen-rich environment at high and low altitude, respectively. The children were treated with non-steroidal anti-asthmatic drugs as clinically needed. Histamine PC20-FEV1 was unaltered during the study period, whereas serum levels of eosinophil cationic protein (ECP) and eosinophil protein X (EPX) showed significant changes when the children were exposed to the offending allergens. The total IgE significantly increased during exposure. The serum levels of myeloperoxidase (MPO) as well as of chemotactic factors for both neutrophils and eosinophils were unaltered during allergen exposure. We conclude that the serum markers of eosinophil activity ECP and EPX are sensitive indices of allergen exposure in asthmatic atopic children.

Airway inflammation in smokers with nonobstructive and obstructive chronic bronchitis

To assess the manifestation and location of airway inflammation in smokers with chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD), we lavaged the airways of 12 smokers with CB and 11 smokers with COPD and coexisting CB (OCB). For comparison, the airways of 5 asymptomatic smokers (AS) and 10 healthy nonsmokers (HNS) were lavaged. In all cases, the first lavage aliquot, labeled "bronchial lavage" (BL), was processed separately from the four subsequent aliquots, which were combined and labeled "bronchoalveolar lavage" (BAL). The composition of BL and BAL fluids indicate an ongoing inflammatory process in the airways of all three groups of smokers. CB patients with obstruction had significantly lower concentrations of inflammatory cells in the BL and BAL fluids compared with subjects with nonobstructed CB. Furthermore, airway obstruction, indicated by a reduced FEV1, was significantly correlated with the concentrations of glutathione (p < 0.001), myeloperoxidase (MPO; p < 0.01), and eosinophil cationic protein (ECP; p < 0.01) in BAL fluids. Taken together, these findings suggest that the manifestations of inflammation present in the airways of smokers with CB are different in those who have developed obstruction compared with those who have not.

Aspects of preanalytical variation of lactoferrin and elastase/alpha 1-protease inhibitor complexes

A number of interesting applications of plasma elastase/alpha 1-protease inhibitor complexes (ELA-PI) and lactoferrin (LAC) have recently been suggested. However, the clinical utility of these components often seems to be low. This might be improved by minimizing the preanalytical variation, if possible. Therefore, we have evaluated the influence of various aspects of sampling and handling conditions on the results obtained when measuring ELA-PI and LAC. Blood samples from both healthy persons as well as patients, who had undergone laparotomy the day before, were investigated. We confirmed the previous observations of higher concentrations of ELA-PI and LAC in serum compared to plasma. This was more pronounced in patients than in healthy adults. In EDTA-blood the most important change was seen in samples from patients when stored at room temperature. In this situation increases of LAC concentrations of 50% and 100% following 2 and 5 h, respectively were found. This in vitro release of LAC was abolished when samples were stored on ice until centrifugation within 5 h. In contrast, a statistically significant increase in ELA-PI of 10% was observed following storage on ice for 2 h of blood specimens drawn from healthy persons. EDTA-plasma obtained by venous puncture following minimal stasis contained 10% higher concentrations of LAC compared to samples drawn from intravenous catheters, while no difference was observed in the case of ELA-PI. However, in one individual prolonged venous stasis resulted in larger differences of both LAC and ELA-PI. Different centrifugation conditions (1500 vs. 3000 x g; room temperature vs. 4 degrees C) did not influence concentrations of LAC or ELA-PI measured, neither did eating a normal meal nor moderate physical activity (30 min walk). In conclusion, ELA-PI and LAC should be measured in EDTA-plasma. Blood must be drawn by venous puncture applying minimal stasis or from indwelling venous catheters. Samples for measuring LAC must be stored on ice until centrifugation. Separation of plasma from cells should be performed as fast as possible, but storage for up to 5 h can be accepted.

An enzyme-linked immunosorbent assay for plasma-lactoferrin. Concentrations in 362 healthy, adult blood donors

Very different concentrations of plasma-lactoferrin in healthy adults have been reported in the literature. We compared three commercially available lactoferrins and lactoferrin purified in our laboratory as calibrators in an ELISA. No statistical differences among these preparations of lactoferrin were detected. The concentration of purified lactoferrin was measured by dry weight, and efforts were made in order to minimize loss of purified lactoferrin by adhesion to tubes etc. and thus, secure accuracy of the method. Dilutions were made in PBS 0.01 mol l-1 with NaCl 0.436 mol l-1, (NH4)2SO4 0.5 mol l-1, BSA 5 gl-1 and normal rabbit IgG 10 mg l-1, which was shown to give parallel dilution curves of primary calibrator, secondary calibrator and plasma samples. No significant difference in the content of lactoferrin in neutrophils (median; range) among men (1.78; 0.83-4.48 micrograms 10(-6) neutrophils; n = 20) and women (2.12; 1.16-9.30 micrograms 10(-6) neutrophils; n = 14) was found. Lactoferrin was analysed in EDTA-plasma obtained from 135 female and 227 male blood donors. Median concentrations were 84.7 and 97.8 micrograms l-1 respectively, while 2.5% and 97.5% reference limits (with 90% confidence intervals) were estimated to 42.9 (38.7-47.4) micrograms l-1 and 166.9 (151.0-186.3) micrograms l-1 for women and 52.3 (49.1-55.6) micrograms l-1 and 189.9 (175.9-206.4) micrograms l-1 for men, respectively.

The effect of immunotherapy on eosinophil accumulation and production of eosinophil chemotactic activity in the lung of subjects with asthma during natural pollen exposure

Two groups of birch pollen--allergic patients with seasonal rhinoconjunctivitis and asthma were followed during two consecutive birch-pollen seasons, one group, N = 10, during a season with high pollen load, and one group, N = 15, during a season of low pollen load. Half the patients were treated with immunotherapy (IT) for 3 and 4 years, respectively. The other half of the patients served as control group (non-IT). Bronchoalveolar lavage (BAL) was performed once before each season and once during the pollen season. Eosinophil (EOS) numbers in BAL were increased (p less than 0.01) during the season with high pollen load but not in the season with a low pollen load, and this increment was absent in the IT-treated group. Also, the EOS cationic protein levels were raised in the non-IT-treated group during the season with a high pollen load. The levels of EOS and neutrophil chemotactic activity were raised in BAL in both seasons in the non-IT-treated group compared with the IT-treated group (p less than 0.02, p less than 0.003, p less than 0.04, and p less than 0.005 in high- and low-load pollen season, respectively). Serum and BAL eosinophil chemotactic activity (ECA) were positively correlated (p less than 0.001). We conclude that there is an influx of active EOSs into the lung of pollen-allergic patients with asthma during a pollen season, which may be abrogated by IT. Furthermore, the generation of ECA appears to be an extremely sensitive marker of antigenic exposure, and the potent inhibition of the generation of ECA by IT may provide a clue as to the mechanism of this treatment.

Self-labeling of human polymorphonuclear leucocyte myeloperoxidase with 125iodine

In order to obtain a radioimmunoassay (RIA) technique for the measurement of human plasma myeloperoxidase (MPO), we purified the enzyme from polymorphonuclear granulocytes (neutrophils), and compared three methods of labeling it with 125Iodine:chloramine T, lactoperoxidase, and an original technique of 'self labeling' based on the ability of the enzyme to oxidize and bind 125I in the presence of H2O2. The chloramine T technique produced a degraded protein, as well shown by a high non-specific binding of tracer to antibody. The lactoperoxidase technique did not succeed in labeling MPO with an adequate specific activity. In contrast, the self-labeling method gave a stable tracer with a specific activity of 23 microCi/micrograms MPO (85 MBq), a satisfactory level of immunoreactivity, and a low-specific binding (less than or equal to 3%). After labeling, purification of tracer was achieved by gel filtration chromatography in phosphate buffer (0.05 M; pH7) to which 0.1% poly-L-lysine was added. The labeled molecule remained stable for 40 days and could be used for RIA with a polyclonal antibody raised in rabbits.

Effect of auranofin on cytokine induced secretion of granule proteins from adherent human neutrophils in vitro

The effect of auranofin on granule protein secretion from neutrophils was investigated by a haemolytic plaque assay which can detect release of lactoferrin and myeloperoxidase from single adherent neutrophils. Lactoferrin secretion in response to N-formyl-methionyl-leucyl-phenylalanine (fMLP) was enhanced at low (0.25-1.0 micrograms/ml) and inhibited at high concentrations of auranofin (50% inhibition (IC50) at 3.7 micrograms/ml). A similar biphasic effect was also seen on degranulation mediated by granulocyte-macrophage colony stimulating factor (GM-CSF) (IC50 1.8 micrograms/ml). In contrast, exocytosis mediated by tumour necrosis factor was inhibited even at low concentrations of auranofin (IC50 0.6 micrograms/ml). Secretion induced by phorbol 12-myristate 13-acetate and A23187 was only inhibited at very high auranofin concentrations (IC50 10 and 8 micrograms/ml respectively). The effect of auranofin on myeloperoxidase secretion was also assessed and the IC50 values for the respective agents were as follows: tumour necrosis factor 0.7 micrograms/ml, fMLP 1.6 micrograms/ml, and phorbol myristate acetate 7.6 micrograms/ml. When neutrophils were preincubated with auranofin (4 micrograms/ml) and then exposed to fMLP, tumour necrosis factor, or GM-CSF in the absence of auranofin, lactoferrin release was enhanced if the preincubation time was short (one to three minutes) and inhibited when the time of preincubation was longer. It was concluded that auranofin, at concentrations achieved in the serum of patients, is a potent inhibitor of cytokine induced release of granule proteins from adherent neutrophils. This finding may be of clinical importance and shed light on the mechanism by which auranofin acts in rheumatoid arthritis.

Reduced granulocyte activation with a heparin-coated device in an in vitro model of cardiopulmonary bypass

Granulocyte activation during cardiopulmonary bypass (CPB), resulting in degranulation, may have adverse effects. Fresh whole human blood and priming solution was circulated through oxygenator/tubing sets coated with functional heparin (n = 7) and through uncoated sets (n = 7) in model CPB. Plasma concentrations of the primary granule protein myeloperoxidase (MPO) and the secondary granule protein lactoferrin (LF) were measured in radioimmunoassays, and the neutrophils were counted. After 120 min, seven to nine times baseline concentrations of LF (p less than 0.0001) were observed with both devices. Increases of MPO were also significant, but significantly larger (p less than 0.01) with the uncoated devices. There was an equivalent reduction in neutrophil numbers in both groups. MPO did not bind to heparin-coated Sephadex particles in gel chromatography. Thus, the heparin coating most likely prevented the release of potentially harmful primary granule proteins, indicating improved biocompatibility. Adhesion of neutrophils and exocytosis of LF, which may be involved in adhesion, were unaffected.

Fast double antibody radioimmunoassay of human granulocyte myeloperoxidase and its application to plasma

The haem enzyme myeloperoxidase (MPO) (EC 1.11.1.7) with a spectral A430/A280 ratio greater than 0.7 and a specific activity of 125 U/mg was purified from isolated human neutrophils. To obtain a radioimmunoassay (RIA) for this enzyme, a specific antiserum against human neutrophil MPO was raised in rabbits and used at an initial dilution of 1/10,000. MPO labelled with 125iodine by a technique of self-labelling in the presence of H2O2, had a specific activity of 24 mCi/mg. After incubation at room temperature (2 h) and separation by double antibody precipitation in the presence of polyethylene glycol, the sensitivity of the RIA was 21 ng/ml. The RIA showed good precision and accuracy with intra- and interassay coefficients of variation of less than 7% for MPO concentrations ranging from 100 to 800 ng/ml, and satisfactory recoveries of known amounts of exogenous MPO in plasma. For the measurement of MPO in blood, the best sampling technique was to collect blood into EDTA. Rapid centrifugation (within 20 min) was necessary for blood collected into heparin. Mean MPO values in normal individuals were 340 +/- 98 ng/ml in EDTA plasma (n = 152) and 332 +/- 82 ng/ml in heparinized plasma (n = 34). When MPO was measured 12-6 h after injury in critically ill patients high values (above 1000 ng/ml) were found in 6/15 patients with multiple injuries. In patients with sepsis (n = 22), MPO values were always above 1000 ng/ml.

Tumor necrosis factor-induced degranulation in adherent human neutrophils is dependent on CD11b/CD18-integrin-triggered oscillations of cytosolic free Ca2+

We have recently been able to correlate closely the "spontaneous" oscillatory activity of cytosolic free Ca2+ in adherent human neutrophils with the ability of tumor necrosis factor (TNF) to induce secretion of granule proteins from these cells. In the present work we show with a single-cell technique that preincubation of human neutrophils with antibodies to CD18, the common beta chain of leukocyte adhesion proteins, inhibits TNF-induced secretion of lactoferrin in a time- and concentration-dependent manner. Similar effects of CD18 antibodies were found on chemotactic factor (fMet-Leu-Phe)- but not on phorbol 12-myristate 13-acetate-induced secretion, suggesting that cell-surface-receptor-mediated secretion is dependent on integrin-associated signals. Similarly, antibodies to CD11b (alpha chain of macrophage 1) also inhibited TNF- and fMet-Leu-Phe- but not phorbol 12-myristate 13-acetate-stimulated release of lactoferrin. Antibodies to CD11a (alpha chain of lymphocyte function-associated antigen 1) or CD11c (alpha chain of p150,95) had only a minimal effect on agonist-induced secretion. Data obtained in several laboratories, including our own, made us suspect that integrin interaction with the surface is responsible for the oscillatory activity of cytosolic free Ca2+ in adherent cells. Indeed, preincubation with antibodies to either CD18 or CD11b, but not to CD11c, inhibited the oscillations of cytosolic free Ca2+ in adherent neutrophils. This inhibitory effect was evident both as a reduction of the number of responding cells and as a reduction of the oscillatory activity in the cells. In conclusion, the oscillatory activity of cytosolic free Ca2+ in adherent neutrophils is mediated through the CD18/CD11b integrins. The generation of this Ca2+ signal may explain how adherence, by way of the integrins, changes the functional properties of the cell and enables TNF to induce secretion.

Myeloperoxidase in human lung lavage. I. A marker of local neutrophil activity

The origin of myeloperoxidase (MPO) in bronchoalveolar lavage (BAL) was investigated in the first part of the study. Radioimmunoassay of the cellular and supernatant MPO content as well as the peroxidase-antiperoxidase (PAP) technique were employed to determine the cellular source of MPO. The concentrations of MPO were measured in serum and BAL in the second part of the study. The aim was to determine whether the capillary bed was also a source of MPO. Neutrophil numbers in BALs obtained from 20 healthy subjects correlated significantly to the concentrations of MPO in cell-free BAL supernatants (r = 0.643, P less than or equal to 0.01). The cellular content of MPO in mixed BAL cells was significantly correlated to the number of neutrophils in the mixture (r = 0.536, P less than 0.05), but not to the number of any other cells. Moreover, the PAP-technique identified MPO in lung tissue neutrophils in resection specimens obtained from three patients undergoing surgery. This technique also revealed strong MPO activity in all BAL neutrophils and a weak activity in merely 4% of the alveolar macrophages in cytospin preparations obtained from seven BALs. High BAL/serum ratio of MPO concentrations suggests that MPO is of local origin, rather than passively diffused from the circulating pool. We therefore conclude that strong evidence suggests that MPO in BAL originates from lung neutrophils and that BAL MPO content may be used to estimate the neutrophil presence or activation in epithelium lining fluid.

Transfer of 99mTc DTPA and bronchoalveolar lavage findings in patients with asymptomatic extrinsic allergic alveolitis

An investigation was performed to determine whether symptom free patients with previously diagnosed extrinsic allergic alveolitis had signs of inflammation in the lung. Pulmonary clearance of inhaled technetium-99m labelled diethylene triamine penta-acetic acid (DTPA) was measured in seven patients with a history of extrinsic allergic alveolitis but with no symptoms at the time of the study and in 12 control subjects. Monoexponential clearance curves were obtained in all 12 control subjects. In contrast, lung clearance was abnormal in five of the seven patients: biexponential clearance curves were noted in four and an abnormally rapid monoexponential curve in one. Bronchoalveolar lavage was performed in all patients. Fluid from the second and third aliquots showed increased concentrations of albumin and urea in fluids from the patients, suggesting increased plasma leakage through the alveolocapillary membranes. More eosinophils and more eosinophil cationic protein were also found in the lavage fluid from the patients. The trend towards increased numbers of eosinophils in patients with abnormal lung clearance of DTPA suggests that this may be due to a continuing inflammatory reaction. Lung inflammation was also suggested by the fact that less leukotriene B4 was secreted by cultured alveolar macrophages obtained from patients than by control macrophages. It is concluded that symptom free patients with previous extrinsic allergic alveolitis have continuing alveolar disease as shown by lung clearance and lavage findings.