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.

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.

Proinflammatory cytokines upregulate mRNA expression and secretion of vascular endothelial growth factor in cultured human airway smooth muscle cells.

Airflow obstruction in chronic airway disease is associated with airway and pulmonary vascular remodeling, of which the molecular mechanisms are poorly understood. Paracrine actions of angiogenic factors released by resident or infiltrating inflammatory cells following activation by proinflammatory cytokines in diseased airways could play a major role in the airway vascular remodeling process. Here, the proinflammatory cytokines interleukin (IL)-1beta, and tumor necrosis factor (TNF)-alpha were investigated on cell cultures of human airway smooth muscle (ASM) for their effects on mRNA induction and protein release of the angiogenic peptide, vascular endothelial growth factor (VEGF). IL-1beta (0.5 ng/mL) and TNF-alpha (10 ng/mL) each increased VEGF mRNA (3.9 and 1.7 kb) expression in human ASM cells, reaching maximal levels between 16 and 24 and 4 and 8 h, respectively. Both cytokines also induced a time-dependent release of VEGF, which was not associated with increased ASM growth. Preincubation of cells with 1 microM dexamethasone abolished enhanced release of VEGF by TNF-alpha. The data suggest that human ASM cells express and secrete VEGF in response to proinflammatory cytokines and may participate in paracrine inflammatory mechanisms of vascular remodeling in chronic airway disease.

High prevalence of hepatitis G virus infection compared with hepatitis C virus infection in patients undergoing chronic hemodialysis.

A recently discovered non-A-E hepatitis virus has been designated as hepatitis G virus (HGV) and identified as a new member of the Flaviviridae family. Infection by this virus is thought to be associated with blood-borne hepatitis and usually in the presence of hepatitis C or hepatitis B virus (HBV) infection. In this study, the presence of HGV-RNA in serum or plasma and the prevalence of antibodies against an HGV envelope protein (E2) were investigated in patients undergoing chronic hemodialysis using a sensitive reverse-transcriptase polymerase chain reaction and an enzyme-linked immunosorbent assay, respectively. HGV-RNA was detected in 19 of 112 patients investigated (17%) and anti-E2 antibodies were detected in 15 of 106 patients studied (14.2%). With the exception of two patients, the appearance of anti-E2 is associated with the clearance of serum HGV-RNA. The total prevalence of current (HGV-RNA positivity) and/or past (anti-E2 positivity) HGV infection in this patient population is thus 28.6% (32 of 112 patients were positive for serum HGV-RNA and/or anti-E2 antibodies). In apparently healthy blood donors, serum HGV-RNA was detected in four of 358 individuals (1.12%) and anti-E2 was not detected in 50 individuals investigated. From the 19 patients with serum HGV-RNA positivity, nine were coinfected with other hepatitis viruses (seven with HBV; one with HBV, hepatitis C virus [HCV], and hepatitis D virus; and one with HBV and cytomegalovirus). Thirteen of 15 patients with anti-E2 positivity (10 were positive for only anti-E2 and three were also positive for anti-HBc) had no detectable HGV-RNA. In two patients, both HGV-RNA and anti-E2 antibodies were concomitantly present (both patients were coinfected with HCV or HBV). Of the HGV-infected patients, only three who were coinfected with HBV showed elevated serum alanine aminotransferase levels. The serum HCV-RNA and/or anti-HCV were detected in five (4.5%) of 112 patients. From these findings, we conclude that there is a high prevalence of HGV infection (28.6%) compared with HCV (4.5%) in patients undergoing hemodialysis in our hospital. However, approximately 50% of patients had spontaneously lost the viremia and developed anti-HGV-E2 antibodies. We confirm that HGV infection alone is not associated with elevated serum transaminases, and the appearance of anti-HGV-E2 is usually accompanied with clearance of serum HGV-RNA. In contrast to the results of our previous study, the majority of patients infected with HGV are not coinfected with HCV, indicating that HGV is capable of independent transmission. It is likely that there is a preferential HGV acquisition in the hemodialysis unit. The clinical significance of long-term infection with HGV remains to be established.