A randomised controlled trial of azithromycin to prevent chronic rejection after lung transplantation.

Azithromycin reduces airway inflammation and improves forced expiratory volume in 1 s (FEV1) in chronic rejection or bronchiolitis obliterans syndrome (BOS) after lung transplantation (LTx). Azithromycin prophylaxis might prevent BOS. A double-blind randomised controlled trial of azithromycin (n = 40) or placebo (n = 43), initiated at discharge and administered three times a week for 2 yrs, was performed in 2005-2009 at the Leuven University Hospital (Leuven, Belgium). Primary end-points were BOS-free and overall survival 2 yrs after LTx; secondary end-points were acute rejection, lymphocytic bronchiolitis and pneumonitis rate, prevalence of pseudomonal airway colonisation or gastro-oesophageal reflux, and change in FEV1, airway and systemic inflammation over time. Patients developing BOS were assessed for change in FEV1 with open-label azithromycin. BOS occurred less in patients receiving azithromycin: 12.5 versus 44.2% (p = 0.0017). BOS-free survival was better with azithromycin (hazard ratio 0.27, 95% CI 0.092-0.816; p = 0.020). Overall survival, acute rejection, lymphocytic bronchiolitis, pneumonitis, colonisation and reflux were comparable between groups. Patients receiving azithromycin demonstrated better FEV1 (p = 0.028), and lower airway neutrophilia (p = 0.015) and systemic C-reactive protein levels (p = 0.050) over time. Open-label azithromycin for BOS improved FEV1 in 52.2% patients. No serious adverse events were noted. Azithromycin prophylaxis attenuates local and systemic inflammation, improves FEV1 and reduces BOS 2 yrs after LTx.

Diagnostic value of antibodies against Pseudomonas aeruginosa in bronchoalveolar lavage fluid after lung transplantation.

BACKGROUND: Pseudomonal airway colonization is a risk factor for chronic allograft dysfunction after lung transplantation (LTx). Pseudomonas aeruginosa exoproteases are involved in initiating colonization, and immune complexes directed against these proteases may activate innate immune responses. OBJECTIVE: To investigate whether specific antibodies against pseudomonal proteases could be measured in bronchoalveolar lavage (BAL) fluid, whether they are associated with innate immune responses, and whether they could identify patients with chronic P. aeruginosa colonization after LTx. MATERIALS AND METHODS: BAL fluid from 40 noncolonized and 25 chronically colonized LTx recipients was retrospectively assayed for IgG antibodies against P. aeruginosa alkaline protease (AP), elastase (Ela), and exotoxin (Exo), and for BAL total and differential cell counts and IL-8 protein concentration. RESULTS: BAL anti-Ela and anti-Exo antibody titers were significantly increased in colonized compared with noncolonized patients (P = .009 and P = .02, respectively), whereas anti-AP titers were comparable (P = .79). Antibody titers strongly correlated with each other, and anti-Ela and anti-Exo titers, but not anti-AP titers, also correlated with BAL total cellularity, neutrophilia, and IL-8 protein concentration. Anti-Ela antibodies demonstrated the greatest diagnostic value in receiver operating characteristic analysis to detect chronic airway colonization (P = .009), followed by anti-Exo (P = .02) and anti-AP (P = .79). A combination of all 3 antibodies resulted in overall sensitivity of 45% (95% confidence interval [CI], 29.3-61.5), specificity of 88% (95% CI, 68.8-97.5), and positive predictive value of 55% (95% CI, 38.5-70.7). CONCLUSION: P. aeruginosa proteases in BAL may be associated with local innate immune responses, and could have the potential to enable detection of chronic colonization after LTx.

Azithromycin reduces pulmonary fibrosis in a bleomycin mouse model.

Idiopathic pulmonary fibrosis (IPF) is a devastating disease without proper treatment. Despite intensive research, the exact underlying pathogenesis remains elusive. It is regarded as a continuous injury, resulting in inflammation, infiltration, and proliferation of fibroblasts and extracellular matrix deposition, leading to an irreversible restrictive lung function deterioration and death. In this study the effect of azithromycin, a macrolide antibiotic on bleomycin-induced pulmonary fibrosis was investigated. C57BL/6 mice were intratracheally instilled with bleomycin (0.5 mg/kg) or saline. In the bleomycin group, half of the animals received azithromycin every other day from day 1 on. Bronchoalveolar lavage and histology were performed at days 7 and 35, and pulmonary function tests on day 35. At day 35, fibrotic lesions (spindle cell proliferation/collagen I deposition) were paralleled by a restrictive lung function pattern. Alterations were found in neutrophils and macrophages (innate immunity) and in T(H)2, T(H)17, and Treg cytokines (adaptive immunity). Azithromycin significantly reduced both fibrosis and the restrictive lung function pattern. This study demonstrated a beneficial effect of azithromycin on bleomycin-induced pulmonary fibrosis. A possible mechanism could be a modulation of both innate immunity and adaptive immunity. These findings might suggest a potential role for azithromycin in the treatment of IPF.

C-reactive protein in bronchoalveolar lavage fluid is associated with markers of airway inflammation after lung transplantation.

BACKGROUND: C-reactive protein (CRP), an acute-phase marker of systemic inflammation, may also be a local regulator of the pulmonary immune system. Its role in lung transplantation (LT), however, is unclear. We hypothesized that CRP in bronchoalveolar lavage (BAL) fluid might be associated with airway inflammation or remodeling. Therefore, it could play a role in the development of bronchiolitis obliterans syndrome (BOS). PATIENTS AND METHODS: A total of 100 LT recipients who had undergone transplantation between August 2001 and August 2005 were included in the current cross-sectional study. Patients who were evaluated at 90 days after LT were categorized as either stable (n = 36), colonized (n = 25), or suffering from infection (n = 16) or acute rejection (n = 23). BAL CRP, cell differentials, and interleukin (IL), IL8, transforming growth factor beta (TGFbeta), and vascular endothelial growth factor (VEGF) protein levels, as well as blood leukocytosis, plasma CRP, and forced expiratory value in 1 second (FEV(1); % predicted) were compared between groups. We analyzed the correlation of BAL CRP with inflammatory or remodeling markers and FEV(1). RESULTS: Compared with stable LT recipients, BAL CRP was significantly increased in patients with infection or acute rejection (P < .0001), but not in those with colonization. Generally, BAL CRP levels positively correlated with BAL total cell count, neutrophilia, and IL8 levels, as well as with plasma CRP levels (P < .0001). An inverse correlation was observed with BAL macrophages (P < .01), VEGF (P < .0001), and FEV(1) (P < .0001). Only a trend for a positive, respectively inverse correlation was seen for BAL IL6 and TGFbeta. CONCLUSIONS: The current data corroborate a possible role for CRP in airway inflammation after LT. Its importance for BOS should therefore be further elucidated.

Efficacy of total lymphoid irradiation in azithromycin nonresponsive chronic allograft rejection after lung transplantation.

Bronchiolitis obliterans syndrome (BOS) remains a major problem after lung transplantation. Azithromycin seems to be beneficial in some patients with established BOS. We investigated the efficacy of total lymphoid irradiation (TLI) in 6 BOS patients with a continuous decline in FEV(1), despite treatment with azithromycin for a mean of 12 +/- 13 (range, 1-35) months. A historical control group consisted of 5 patients with declining FEV(1), also nonresponders to azithromycin and those not treated with TLI. All 6 TLI patients received the total dose of 8 Gy in 10 sessions. There was a significant change in the decline of the FEV(1) after TLI treatment (from 221 +/- 107 to 94 +/- 79 mL/mo; P = .041). Three patients died, due to BOS progression, overwhelming pneumonia, and sudden cardiac arrest, respectively, 3.5, 11, and 26 months after TLI; two patients underwent retransplantation at 6 and 19 months after TLI, respectively. The sixth patient remains stable in BOS stage 3 after a follow-up period of 24 months. In the control group, there was no significant change in FEV(1) decline (209 +/- 97 mL/mo before versus 193 +/- 81 mL/mo after starting azithromycin; P = not significant). Two patients remain stable in BOS stage 3, 1 died of BOS progression, and the 5th patient is scheduled for retransplantation. We conclude that patients who do not or no longer respond to azithromycin may benefit from TLI, as suggested by a decreased rate in decline of the FEV(1).

Plasma C-reactive protein levels correlate with markers of airway inflammation after lung transplantation: a role for systemic inflammation in bronchiolitis obliterans syndrome?

OBJECTIVE: Plasma C-reactive protein (CRP) concentration has been associated with allograft dysfunction in cardiac and renal transplantation; data in lung transplantation (LTx), however, are lacking. We hypothesized that in Ltx, systemic inflammation may be associated with airway inflammation, which has an important role in the development of chronic allograft dysfunction or bronchiolitis obliterans syndrome after LTx. METHODS: In this retrospective, longitudinal, cohort study, plasma CRP concentration, bronchoalveolar lavage (BAL) inflammatory markers (interleukin [IL]-6 and IL-8 protein levels and cell differentials), and pulmonary function (forced expiratory volume in 1 second) were evaluated in 100 LTx recipients at discharge and at 3-, 6-, and 12-month follow-up. The Spearman rank test was used to determine a possible relationship between these parameters at each routine follow-up visit. RESULTS: Plasma CRP concentration positively correlated with BAL total cell count and neutrophilia, whereas there was a negative correlation with pulmonary function at discharge and at 3 and 6 months after LTx. A correlation between plasma CRP concentration and BAL interleukin levels was present at discharge (IL-6 and IL-8) and at 6 months (IL-8) after LTx. CONCLUSION: Systemic inflammation and IL-8-mediated neutrophilic airway inflammation seem to be associated after LTx. Therefore, systemic inflammation has a possible role in the development of bronchiolitis obliterans syndrome after LTx.

Follicular bronchiolitis: a rare cause of bronchiolitis obliterans syndrome after lung transplantation: a case report.

This case report is the first confirmed case of follicular bronchiolitis (FB), a rare bronchiolar disorder characterized by peribronchiolar lymphoid follicles, in a series of over 400 lung transplantations performed in our center. It is to our knowledge, the first publication describing FB after lung transplantation (LTx), presenting as chronic allograft dysfunction or bronchiolitis obliterans syndrome (BOS).

The role of the IL23/IL17 axis in bronchiolitis obliterans syndrome after lung transplantation.

Bronchiolitis obliterans syndrome (BOS) is the leading cause of death after lung transplantation. Treatment is challenging, as the precise pathophysiology remains unclear. We hypothesize that T(H)17 lineage plays a key role in the pathophysiology of BOS by linking T-cell activation to neutrophil influx and chronic inflammation. In a cross-sectional study, bronchoalveolar lavage (BAL) samples of 132 lung transplant recipients were analyzed. Patients were divided in four groups: stable or suffering from infection (INF), acute rejection (AR) or BOS. The upstream T(H)17 skewing (TGF-beta/IL1beta/IL6/IL23), T(H)17 counteracting (IL2), T(H)17 effector cytokine (IL17) and the principal neutrophil-attracting chemokine (IL8), were quantified at the mRNA or protein level in combination with the cell profiles. The BOS group (n = 36) showed an increase in IL1beta protein (x1.5), IL6 protein (x3), transforming growth factor-beta (TGF-beta) mRNA (x3), IL17 mRNA (x20), IL23 mRNA (x10), IL8 protein (x2), IL8 mRNA (x3) and a decrease in IL2 protein (x0.8). The infection group (n = 11) demonstrated an increase in IL1beta protein (x5), IL6 protein (x20), TGF-beta mRNA (x10), IL17 mRNA (x300), IL23 mRNA (x200) and IL8 protein (x6). The acute rejection group (n = 43) only revealed an increase in IL6 protein (x6) and IL8 protein (x2) and a decrease in IL2 protein (x0.7). Lymphocytes and neutrophils were increased in all groups compared to the stable (n = 42). Our findings demonstrate the IL23/IL17 axis to be involved in the pathophysiology of BOS potentially triggering the IL8-mediated neutrophilia. IL6, IL1beta and IL23 seem to be skewing cytokines and IL2 a counteracting cytokine for T(H)17 alignment. The involvement of TGF-beta could not be confirmed, either as T(H)17 steering or as counteracting cytokine.