Amelioration of lung reperfusion injury by L- and E- selectin blockade

OBJECTIVE: Reperfusion injury is the main reason for early graft failure after lung transplantation. Inhibition of the adherence of polymorphonuclear leukocytes to activated endothelium by blocking L- and E-selectins (antibody EL-246) could potentially inhibit reperfusion injury. METHODS: Reperfusion injury was induced in a left lung autotransplant model in sheep. After hilar stripping the left lung was flushed with Euro-Collins solution and preserved for 2 h in situ at 15 degrees C. After reperfusion right main bronchus and pulmonary artery were occluded leaving the animal dependent on the reperfused lung (control, n = 6). Pulmonary function was assessed by alveolo-arterial oxygen difference (AaDO2) and pulmonary vascular resistance (PVR), the chemiluminescence of isolated neutrophils, as well as the release of beta-N-acetyl-glucosaminidase (beta-NAG) served as indicator of neutrophilic activation. Extravascular lung water was an indicator for pulmonary edema formation. EL-246 group animals (n = 6) were treated additionally with 1 mg/kg BW of EL-246 given prior and during reperfusion. RESULTS: After 3 h of reperfusion five control animals developed alveolar edema compared to one animal in the EL-246 group (P = 0.08). AaDO2 (mm Hg) was significantly higher in the control compared to the EL-246 group (510 +/- 148 vs. 214 +/- 86). PVR (dyn x s x cm(-5)) was significantly increased in the control compared to the EL-246 group (656 +/- 240 vs. 317 +/- 87). Neutrophilic activation was significantly lower in the EL-246 group. Extravascular lung water was significantly lower compared to control (6.88 +/- 1.0 vs. 13.4 +/- 2.8 g/g blood-free lung weight). CONCLUSIONS: Treatment with EL-246 results in improved pulmonary function and less in vivo PMN activation in this experimental model. Further studies are necessary to evaluate the possible role of selectin blockade in amelioration of reperfusion injury in human lung transplantation.

Early biochemical indicators of the obliterative bronchiolitis syndrome in lung transplantation

The diagnosis of the obliterative bronchiolitis syndrome in lung transplantation is presently best established by evaluation of postoperative lung function tests. Unfortunately the decline in lung function occurs only when obliteration has progressed significantly and is therefore not an early predictive indicator. To distinguish patients at increased risk for the development of obliterative bronchiolitis, we regularly assessed the chemiluminescence response of polymorphonuclear leukocytes, opsonic capacity, and plasma elastase/beta-N-acetylglucosaminidase in 52 outpatients (25 women and 27 men; mean age 45 +/- 12 years) who underwent transplantation between January 1991 and January 1992. Recent onset bronchiolitis within the described observation period occurred in 16 patients (group obliterative bronchiolitis). A matched cohort of 16 patients was formed according to type of procedure, age and follow-up (control) from the remaining 36 patients. Data obtained from a period 6 months before clinical onset of the syndrome showed a significant drop of the opsonic capacity (group obliterative bronchiolitis = 87% +/- 7%; control = 100% +/- 9%; p < 0.023) and rise of the N-acetyl-D-glucosaminidase (group obliterative bronchiolitis = 7.5 +/- 2 U/L; control = 5.8 +/- 1.8 U/L; p < 0.04). No correlation was found between the number of infectious events or rejection episodes and the incidence of obliterative bronchiolitis. According to these results, it can be concluded that a decrease in the plasma opsonic capacity and a rise in beta-N-acetylglucosaminidase may be early markers before clinical onset of obliterative bronchiolitis. The nonspecific immune system may therefore play an important role in the development of obliterative bronchiolitis.

Comparison of two non-bronchoscopic methods for evaluating inflammation in patients with acute hypoxaemic respiratory failure

INTRODUCTION: The simple bedside method for sampling undiluted distal pulmonary edema fluid through a normal suction catheter (s-Cath) has been experimentally and clinically validated. However, there are no data comparing non-bronchoscopic bronchoalveolar lavage (mini-BAL) and s-Cath for assessing lung inflammation in acute hypoxaemic respiratory failure. We designed a prospective study in two groups of patients, those with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) and those with acute cardiogenic lung edema (ACLE), designed to investigate the clinical feasibility of these techniques and to evaluate inflammation in both groups using undiluted sampling obtained by s-Cath. To test the interchangeability of the two methods in the same patient for studying the inflammation response, we further compared mini-BAL and s-Cath for agreement of protein concentration and percentage of polymorphonuclear cells (PMNs). METHODS: Mini-BAL and s-Cath sampling was assessed in 30 mechanically ventilated patients, 21 with ALI/ARDS and 9 with ACLE. To analyse agreement between the two sampling techniques, we considered only simultaneously collected mini-BAL and s-Cath paired samples. The protein concentration and polymorphonuclear cell (PMN) count comparisons were performed using undiluted sampling. Bland-Altman plots were used for assessing the mean bias and the limits of agreement between the two sampling techniques; comparison between groups was performed by using the non-parametric Mann-Whitney-U test; continuous variables were compared by using the Student t-test, Wilcoxon signed rank test, analysis of variance or Student-Newman-Keuls test; and categorical variables were compared by using chi-square analysis or Fisher exact test. RESULTS: Using protein content and PMN percentage as parameters, we identified substantial variations between the two sampling techniques. When the protein concentration in the lung was high, the s-Cath was a more sensitive method; by contrast, as inflammation increased, both methods provided similar estimates of neutrophil percentages in the lung. The patients with ACLE showed an increased PMN count, suggesting that hydrostatic lung edema can be associated with a concomitant inflammatory process. CONCLUSIONS: There are significant differences between the s-Cath and mini-BAL sampling techniques, indicating that these procedures cannot be used interchangeably for studying the lung inflammatory response in patients with acute hypoxaemic lung injury.

Cerebral extension of steroid-responsive meningitis arteritis in a boxer

A comatose 30-month-old, entire male boxer was presented because of an acute history of a cluster of three to four seizures. Neurological examination suggested a diffuse to multifocal intracranial lesion. Magnetic resonance tomography revealed symmetrical multifocal to diffuse changes of the cerebral grey matter and ependymal lining with sediment in the lateral ventricles. Haematological examination revealed leucocytosis with neutrophilia. Cerebrospinal fluid examination revealed high protein concentration and polymorphonuclear pleocytosis. Despite antiepileptic treatment, therapy against increased intracranial pressure and antibiosis, the dog's condition continued to deteriorate and he was euthanased. Pathological examination revealed fibrinosuppurative meningo-ependymitis and necrotising arteritis throughout the brain. In addition, chronic inflammation and arterial stenosis was found in the spinal meninges. No infectious agent was found. A diagnosis of steroid-responsive meningitis arteritis was made. The massive extension into the meninges and ventricular system of the forebrain has not been described previously in dogs with steroid-responsive meningitis arteritis and should be considered in the differential diagnosis when an intracranial suppurative infection is suspected.

Clinical parameters, intestinal function, and IGF1 concentrations in colostrum-deprived and colostrum-fed newborn pony foals.

Colostrum (COL) contains cytokines and growth factors that may enhance intestinal development in neonates. The hypothesis of this study was that besides providing immunoglobulins, COL is important for intestinal function and meconium release in foals. Newborn foals were either fed COL (n = 5) or an equal amount of milk replacer (MR, n = 7) during the first 24 hours of life. To ensure passive immunity, all foals received 1 L plasma. Postnatal development, meconium release, intestinal motility, white blood cell count, insulin-like growth factor 1, and intestinal absorptive function (xylose absorption test) were evaluated. Clinical findings and meconium release were not affected by feeding of COL or MR. Ultrasonography revealed a slightly larger jejunum and stomach in group COL versus MR (P < 0.05). The percentage of polymorphonuclear leucocytes was higher in foals of group MR versus group COL (P < 0.05) and the percentage of lymphocytes was lower in MR compared with COL foals (P < 0.05). Plasma insulin-like growth factor 1 concentration increased during the first 14 days after birth in both groups. A xylose absorption test on Day 5 revealed similar increases in plasma xylose concentrations after oral intake. In conclusion, feeding of COL versus MR was without effect on meconium release and intestinal absorptive function. Differences between foals fed COL and MR with regard to intestinal function are apparently without clinical relevance. In foals that have not received maternal COL, there is no major risk of intestinal problems if they are fed MR and provided with immunoglobulins by transfusion of plasma.

SerpinB1 is critical for neutrophil survival through cell-autonomous inhibition of cathepsin G

Bone marrow (BM) holds a large reserve of polymorphonuclear neutrophils (PMNs) that are rapidly mobilized to the circulation and tissues in response to danger signals. SerpinB1 is a potent inhibitor of neutrophil serine proteases neutrophil elastase (NE) and cathepsin G (CG). SerpinB1 deficiency (sB1(-/-)) results in a severe reduction of the BM PMN reserve and failure to clear bacterial infection. Using BM chimera, we found that serpinB1 deficiency in BM cells was necessary and sufficient to reproduce the BM neutropenia of sB1(-/-) mice. Moreover, we showed that genetic deletion of CG, but not NE, fully rescued the BM neutropenia in sB1(-/-) mice. In mixed BM chimera and in vitro survival studies, we showed that CG modulates sB1(-/-) PMN survival through a cell-intrinsic pathway. In addition, membrane permeabilization by lysosomotropic agent l-leucyl-l-leucine methyl ester that allows cytosolic release of granule contents was sufficient to induce rapid PMN death through a CG-dependent pathway. CG-mediated PMN cytotoxicity was only partly blocked by caspase inhibition, suggesting that CG cleaves a distinct set of targets during apoptosis. In conclusion, we have unveiled a new cytotoxic function for the serine protease CG and showed that serpinB1 is critical for maintaining PMN survival by antagonizing intracellular CG activity.

IL-9 and its receptor are predominantly involved in the pathogenesis of UC.

OBJECTIVE Several pathogenic roles attributed over the past two decades to either T helper (Th)1 or Th2 cells are increasingly becoming associated with interleukin (IL)-17 and most recently IL-9 signalling. However, the implication of IL-9 in IBD has not been addressed so far. DESIGN We investigated the expression of IL-9 and IL-9R by using peripheral blood, biopsies and surgical samples. We addressed the functional role of IL-9 signalling by analysis of downstream effector proteins. Using Caco-2 cell monolayers we followed the effect of IL-9 on wound healing. RESULTS IL-9 mRNA expression was significantly increased in inflamed samples from patients with UC as compared with controls. CD3(+) T cells were major IL-9-expressing cells and some polymorphonuclear leucocytes (PMN) also expressed IL-9. IL-9 was co-localised with the key Th9 transcription factors interferon regulatory factor 4 and PU.1. Systemically, IL-9 was abundantly produced by activated peripheral blood lymphocytes, whereas its receptor was overexpressed on gut resident and circulating PMN. IL-9 stimulation of the latter induced IL-8 production in a dose-dependent manner and rendered PMN resistant to apoptosis suggesting a functional role for IL-9R signalling in the propagation of gut inflammation. Furthermore, IL-9R was overexpressed on gut epithelial cells and IL-9 induced STAT5 activation in these cells. Moreover, IL-9 inhibited the growth of Caco-2 epithelial cell monolayers in wound healing experiments. CONCLUSIONS Our results provide evidence that IL-9 is predominantly involved in the pathogenesis of UC suggesting that targeting IL-9 might become a therapeutic option for patients with UC.