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Rationale: Bronchiolitis obliterans syndrome (BOS) remains the leading cause of death after lung transplantation. Treatment is difficult, although azithromycin has recently been shown to improve FEV(1). The exact mechanism of action is unclear., Hypotheses: (1) Azithromycin reduces airway neutrophilia and interleukin (IL)-8 and (2) airway neutrophilia predicts the improvement in FEV(1)., Methods: Fourteen lung transplant patients with BOS (between BOS 0-p and BOS 3) were treated with azithromycin, in addition to their current immunosuppressive treatment. Before and 3 mo after azithromycin was introduced, bronchoscopy with bronchoalveolar lavage (BAL) was performed for cell differentiation and to measure IL-8 and IL-17 mRNA ratios., Results: The FEV(1) increased from 2.36 (+/- 0.82 L) to 2.67 L (+/- 0.85 L; p = 0.007), whereas the percentage of BAL neutrophilia decreased from 35.1 (+/- 35.7%) to 5.7% (+/- 6.5%; p = 0.0024). There were six responders to azithromycin (with an FEV(1) increase of > 10%) and eight nonresponders. Using categorical univariate linear regression analysis, the main significant differences in characteristics between responders and nonresponders were the initial BAL neutrophilia (p < 0.0001), IL-8 mRNA ratio (p = 0.0009), and the postoperative day at which azithromycin was started (p = 0.036). There was a significant correlation between the initial percentage of BAL neutrophilia and the changes in FEV(1) after 3 mo (r = 0.79, p = 0.0019)., Conclusion: Azithromycin significantly reduces airway neutrophilia and IL-8 mRNA in patients with BOS. Responders have a significantly higher BAL neutrophilia and IL-8 compared with nonresponders and had commenced treatment earlier after transplantation. BAL neutrophilia can be used as a predictor for the FEV(1) response to azithromycin.

Background: The use of non-heart-beating donors (NHBDs) for lung transplantation is a possible alternative for increasing the number of organs available. The warm ischemic period after circulatory arrest may contribute to a higher degree of primary graft dysfunction, resulting from ischemia-reperfusion injury (IRI). A better understanding of the role of inflammatory cells during the warm ischemic interval may be useful for developing new therapeutic strategies against IRI., Methods: Mice were divided in 7 groups (n = 6/group). In 3 groups, ischemia was induced by clamping the hilum of the left lung for 30, 60 or 90 minutes (Groups [30I], [60I] or [90I], respectively). In 3 more groups, the lung was reperfused for 4 hours after identical ischemic intervals (Groups [30I+R], [60I+R] or [90I+R], respectively). Surgical impact was evaluated in a sham group ([sham]). Total and differential cell counts and interleukin-1beta (IL-1beta) protein levels in bronchoalveolar lavage (BAL) were determined and their correlations were investigated., Results: Total cell, macrophage and lymphocyte numbers and IL-1beta protein levels increased progressively with longer ischemic intervals. A significant rise in BAL macrophages and lymphocytes was observed between [60I] and [90I] (p < 0.01 and p < 0.001, respectively). BAL neutrophils only increased after reperfusion with longer ischemic intervals. A positive correlation was found in the ischemic groups between IL-1beta levels and the number of macrophages (r = 0.62; p = 0.0012) and the number of lymphocytes (r = 0.68; p = 0.0002). A positive correlation was found in the reperfusion groups between IL-1beta levels and the number of neutrophils (r = 0.48; p = 0.044)., Conclusions: This study demonstrates for the first time that BAL macrophages and lymphocytes increase significantly during warm ischemia and correlate with IL-1beta levels.

Background: The use of lungs from non-heart-beating donors (NHBD) might significantly alleviate the organ shortage. The tolerable warm ischemic period after cardiac arrest, however, is limited to approximately 1 hour. If the lung could be safely protected inside the cadaver, this time period may be prolonged. This would help to obtain family consent and to organize organ retrieval., Methods: Pigs (30.8 +/- 0.6 kg) were killed, left untouched for 3 hours, and divided into 3 groups. Nebulized N-acetyl cysteine (NAC) (300 mg), a precursor of the antioxidant agent glutathione, was administered during 10 minutes before death in Group I (NAC-NHBD, n = 6) and 15 minutes after death in Group II (NHBD-NAC, n = 6). In the control group, no aerosol was administered (NHBD, n = 6). After a warm ischemic interval of 3 hours, both lungs in all groups were topically cooled for 1 hour. Thereafter, the left lung was prepared for evaluation in an isolated reperfusion circuit. Hemodynamic, aerodynamic, and oxygenation parameters were measured. Wet-to-dry weight ratio (W/D) was calculated after reperfusion. The right lung was used to measure reduced glutathione (GSH) and oxidized glutathione (GSSG) levels (micromol/g) in lung homogenates and total protein levels in bronchial lavage fluid., Results: Pulmonary vascular resistance, mean airway pressure, and W/D were significantly decreased in NAC-NHBD (1930 +/- 144 Dynes x sec x cm(-5), 14.2 +/- 0.5 cm H2O, and 7.4 +/- 0.4; p < 0.01, 0.01, and 0.05, respectively) and NHBD-NAC (1837 +/- 180 Dynes x sec x cm(-5), 13.3 +/- 1.2 cm H2O, and 7.3 +/- 0.3; p < 0.01, 0.05, and 0.05, respectively) when compared with the control group (5051 +/- 530 Dynes x sec x cm(-5), 17 +/- 0.4 cm H2O, 8.5 +/- 0.1, respectively). GSH/GSSG ratio was significantly higher and protein levels were significantly lower in NAC-NHBD (1.7 +/- 0.1 and 1315 +/- 60 microg/ml; p < 0.05 and 0.05, respectively) and NHBD-NAC (1.7 +/- 0.2 and 1475 +/- 159 microg/ml; p < 0.05 and 0.05, respectively) when compared with the control group (1.2 +/- 0.1 and 2150 +/- 200 microg/ml)., Conclusions: Nebulized NAC administered before or shortly after death attenuates early ischemia reperfusion injury via upregulation of glutathione. NAC might be a promising tool to protect the pulmonary graft from both controlled and uncontrolled NHBD.

Background: It has recently become clear that interleukin (IL)-8 plays a role in chronic neutrophilic inflammatory disorders, such as chronic rejection after lung transplantation. We have shown that IL-17--stimulated human airway smooth muscle cells (HASMC) are able to produce IL-8. The aim of this study was to determine whether p38 mitogen-activated protein kinase (MAPK), c-Jun amino-terminal kinase (JNK), p42/p44 extracellular signal-related kinase (ERK) and nuclear factor-kappaB (NF-kappaB) are involved in IL-17--induced IL-8 production in HASMC in vitro., Methods: We used human airway smooth muscle cells in culture. Western blotting was done to obtain data regarding activation of MAPK. Furthermore, we used specific inhibitors of MAPK to investigate their involvement in IL-17--induced IL-8 release, which was measured by enzyme-linked immunosorbent assay (ELISA)., Results: Western blotting clearly demonstrated that p38 MAPK, JNK and p42/p44 ERK were activated by IL-17 in HASMC. Using SB203580, a specific inhibitor of p38 MAPK, we detected a concentration-dependent inhibition of IL-17--induced IL-8 production with a maximal decrease of 63 +/- 5% (n=8, p<0.01). Curcumin, a specific inhibitor of JNK, also concentration-dependently reduced IL-17--induced IL-8 production, with a maximal decrease of 82+/-4% (n=8, p<0.01). U0126, a specific inhibitor of p42/p44 ERK, induced a maximal decrease of 84+/-5% (n=8, p<0.001). Pyrrolydine dithiocarbamate (PDTC), an inhibitor of NF-kappaB, caused a 70+/-5% (n=8, p<0.01) decrease in IL-17--induced IL-8 production., Conclusions: We found that IL-17 induces activation of p38MAPK, JNK and p42/p44ERK in HASMC. We also found that p38MAPK, JNK, p42/p44 ERK and NF-kappaB play an important role in IL-17--induced IL-8 production in HASMC in vitro. This may open up new opportunities for further treatment of this disease.

Background: Viability testing of the pulmonary graft retrieved from the non-heart-beating donor (NHBD) is mandatory for successful outcome after lung transplantation. Functional assessment by ex vivo reperfusion, however, remains a cumbersome procedure. In this study, therefore, we wanted to investigate the possible value of the proinflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) measured in bronchial lavage fluid (BLF) in predicting functional outcome of the pulmonary graft after reperfusion., Methods: Domestic pigs (29.9 +/- 0.56 kg) were sacrificed and divided in 5 groups (n = 5/group). In the non-ischemic group (NHBD-0), the heart-lung block was explanted immediately. In the other groups the animals were left untouched with increasing time intervals (1 hour = NHBD-1; 2 hours = NHBD-2; 3 hours = NHBD-3). Thereafter both lungs were cooled topically via chest drains up to a total ischemic interval of 4 hours. Finally, in the heart-beating donor group lungs were flushed and stored for 4 hours (4 degrees C) [HBD]. BLF samples were taken from the right lung in all groups after explantation for measurement of IL-1beta and TNF-alpha and the left lung was prepared for evaluation in an isolated reperfusion circuit. Haemodynamic, aerodynamic and oxygenation parameters were measured. Wet-to-dry weight ratio (W/D) was calculated after reperfusion., Results: Graft function deteriorated with increasing time intervals after death. A strong correlation was found between the increase of IL-1beta concentration measured in BLF and the increase in pulmonary vascular resistance (r = 0.80), mean airway pressure (r = 0.74) and wet-to dry weight ratio (r = 0.78); (p < 0.0001, for all parameters). No significant differences in TNF-alpha levels in BLF were observed amongst groups (p = 0.933)., Conclusions: IL-1beta in BLF prior to reperfusion correlated well with graft function and may therefore be a useful, non-invasive marker that can predict the viability of the pulmonary graft from the NHBD.

Background: Long-term survival of lung transplantation is threatened by obliterative bronchiolitis, or its clinical equivalent, bronchiolitis obliterans syndrome. With a prevalence of >50% at 5 years after transplantation, it has emerged as the most significant long-term complication. Neutrophilic inflammation and increased interleukin (IL)-8 production seem to be part of the basic pathophysiologic mechanism of chronic rejection. Recently, it has been suggested that reactive oxygen species may also play an important role in the pathogenesis because they are known to induce smooth muscle proliferation., Methods: Human airway smooth muscle cells in vitro were stimulated with IL-17 (0.1 to 10 ng/ml) or with IL-17 (10 ng/ml) and the anti-oxidative agent N-acetylcysteine (1 micromol/liter to 10 mmol/liter). Production of 8-isoprostane was measured with a commercially available enzyme immunoassay kit and production of IL-8 was measured using a standard enzyme-linked immunoassay technique., Results: IL-17 produced a concentration-dependent increase in 8-isoprostane with a maximum of 136.5 +/- 15.5 pg/ml with IL-17 (10 ng/ml, p < 0.001, n = 12, vs unstimulated cells). N-acetylcysteine (NAC) was able to decrease IL-17-induced 8-isoprostane production, with a maximum decrease of 59.3 +/- 9% (p < 0.001, n = 12) with 10 mmol/liter of N-acetylcysteine, which also decreased IL-17-induced IL-8 production in a concentration-dependent manner (with maximum inhibition of 86.3% when combined with NAC 10 mmol/liter as compared with IL-17 alone)., Conclusions: We demonstrated that human airway smooth muscle cells, when stimulated with IL-17, are able to produce 8-isoprostane, which could be inhibited by adding N-acetylcysteline, and which was also able to decrease IL-17-induced IL-8 production. The clinical significance of these in vitro findings for prevention or treatment of chronic rejection after lung transplantation remains to be investigated.

Bronchiolitis obliterans syndrome is the major constraint on the long-term survival after lung transplantation. Both neutrophils and interleukin (IL)-8, a potent neutrophil attractant, have been shown to play an important role in the pathophysiology of obliterative bronchiolitis. We investigated the potential role of human airway smooth muscle cells in obliterative bronchiolitis by studying their release of IL-8 after stimulation with IL-17, a novel T-cell-derived chemokine capable of attracting and activating neutrophils. We demonstrated a significant increase in IL-8 release, reaching a concentration of 86.6 ng/ml (SEM 1.9 ng/ml) with 100 ng/ml IL-17 (p < 0.01, n = 4), as compared with non-stimulated cells. This IL-17-mediated IL-8 release could not be inhibited by dexamethasone. We conclude that human airway smooth muscle cells may play an important pro-inflammatory role in neutrophilic inflammatory diseases such as chronic rejection after lung transplantation; furthermore, IL-17 may be the link between lymphocytes and neutrophils.

Asthma is an inflammatory disease, in which eotaxin, MCP-1 and MCP-3 play a crucial role. These chemokines have been shown to be expressed and produced by IL-1beta-stimulated human airway smooth muscle cells (HASMC) in culture. In the present study we were interested to unravel the IL-1beta-induced signal transduction leading to chemokine production. Using Western blot, we observed an activation of p38 MAPK, JNK kinase and p42/p44 ERK when HASMC were stimulated with IL-1beta. We also observed a significant decrease in the expression and the release of eotaxin, MCP-1 and MCP-3 in the presence of SB203580, an inhibitor of p38 MAPK (71 +/- 6%, P < 0.05, n = 8 and 39 +/- 10% P < 0.01, n = 10 respectively), curcumin, an inhibitor of JNK kinase (83 +/- 4.9% and 88 +/- 3.4% respectively, P < 0.01, n = 4). U0126, an inhibitor of p42/p44 ERK, also produced a significant decrease in chemokine production (46.3 +/- 9%, P < 0.01 n = 10 and 67.8 +/- 12%, P < 0.01, n = 12). Pyrrolydine dithiocarbamate, an inhibitor of NF-kappaB was also able to reduce the eotaxin, MCP-1 and MCP-3 expression and production (50 +/- 13%, P < 0.05, n = 10 and 23 +/- 7%, P < 0.05, n = 12). We conclude that p38 MAPK, JNK kinase, ERK and NF-kappaB are involved in the IL-1beta-induced eotaxin, MCP-1, and MCP-3 expression and release in HASMC.