Henrik Scherstén

Bronchiolitis obliterans syndrome in lung transplant recipients is associated with increased neutrophil activity and decreased antioxidant status in the lung

Long-term survival of lung transplant recipients is limited by the advent of obliterative bronchiolitis and irreversible airways obstruction, e.g. bronchiolitis obliterans syndrome (BOS). This study investigated whether inflammatory cells and their activation markers were increased in bronchoalveolar lavage (BAL) and transbronchial biopsies (TBB) from patients with BOS. Levels of antioxidants in BAL fluid were also assessed. BAL fluid and TBB from six single-lung, two bilateral-lung, and five heart-lung transplanted patients with diagnosis of BOS were compared with 13 transplant recipients without BOS. BAL fluid levels of myeloperoxidase (MPO), eosinophil cationic protein (ECP) and interleukin (IL)-8 were used as markers for the activation and attraction of neutrophils and eosinophils, respectively. Immunohistochemical staining of TBB with monoclonal antibodies to MPO and ECP (EG2) was performed. Significantly increased BAL percentages of neutrophils and levels of MPO were found in patients with BOS. The findings correlated well with the degree of monoclonal staining for MPO in TBB. BAL levels of ECP and IL-8 were significantly increased in BOS patients. BAL concentrations of the water-soluble antioxidants ascorbate, urate and glutathione were generally lower in BOS patients. The results indicate that neutrophil infiltration and activation, as well as oxidative stress, may play a role in the development and/or progression of bronchiolitis obliterans syndrome. Markers for neutrophil activation could have a potential role in monitoring disease activity in patients with this syndrome.

Usefulness of extracorporeal membrane oxygenation as a bridge to lung transplantation: A descriptive study

BACKGROUND This retrospective study investigated early outcome in patients with end-stage pulmonary disease bridged with extracorporeal membrane oxygenation (ECMO) with the intention of lung transplantation (LTx) in 2 Scandinavian transplant centers. METHODS ECMO was used as a bridge to LTx in 16 patients between 2005 and 2009 at Sahlgrenska and Helsinki University Hospitals. Most patients were late referrals for LTx, and all failed to stabilize on mechanical ventilation. Thirteen patients (7 men) who were a mean age of 41 ± 8 years (range, 25-51 years) underwent LTx after a mean ECMO support of 17 days (range, 1-59 days). Mean follow-up at 25 ± 19 months was 100% complete. RESULTS Three patients died on ECMO while waiting for a donor, and 1 patient died 82 days after LTx; thus, by intention-to-treat, the success for bridging is 81% and 1-year survival is 75%. All other patients survived, and 1-year survival for transplant recipients was 92% ± 7%. Mean intensive care unit stay after LTx was 28 ± 18 days (range, 3-53 days). All patients were doing well at follow-up; however, 2 patients underwent retransplantation due to bronchiolitis obliterans syndrome at 13 and 21 months after the initial ECMO bridge to LTx procedure. Lung function was evaluated at follow-up, and mean forced expiratory volume in 1 second was 2.0 ± 0.7 l (62% ± 23% of predicted) and forced vital capacity was 3.1 ± 0.6 l (74% ± 21% of predicted). CONCLUSION ECMO used as a bridge to LTx results in excellent short-term survival in selected patients with end-stage pulmonary disease.

Persistent high BAL fluid granulocyte activation marker levels as early indicators of bronchiolitis obliterans after lung transplant

The major cause of mortality in the long-term in lung transplant recipients is chronic rejection. This is a fibroproliferative process in the small airways leading to obliterative bronchiolitis and progressive loss of lung function, both constituting the clinical entity bronchiolitis obliterans syndrome (BOS). Granulocyte activation has been implicated as one factor behind BOS. Granulocyte markers in bronchoalveolar lavage (BAL) fluid were prospectively and longitudinally studied in order to identify possible association with BOS. BAL fluid from 266 bronchoscopy procedures performed in twelve single lung, eight bilateral lung and five heart/lung transplant recipients were analysed. The majority (19 of 25) were studied for a period of 2 yrs after surgery. Myeloperoxidase (MPO), eosinophil cationic protein (ECP) and interleukin-8 (IL-8) levels were used as indirect markers of activation and attraction of granulocytes. Five patients developed BOS. Ninety-eight episodes of acute rejection, nine of bacterial infection, 19 of cytomegalovirus pneumonitis, nine of Pneumocystis carinii infection, two of aspergillus infection and two of respiratory syncytial virus infection were diagnosed. BOS patients had significantly higher mean levels of MPO, ECP and IL-8 compared to patients without BOS, irrespective of acute rejection status. Over time, the five patients with BOS had significantly elevated BAL fluid levels of MPO and ECP as well as neutrophil percentages, and in four patients this increase preceded the clinical diagnosis of BOS by several months. Elevated bronchoalveolar lavage fluid neutrophil percentage as well as levels of the granulocyte activation markers myeloperoxidase and eosinophil cationic protein appear to be early signs of development of BOS in lung transplant recipients.

Lung transplantation in patients with cystic fibrosis and Mycobacterium abscessus infection

Mycobacterium abscessus lung disease is difficult to treat and has been considered a strong relative contraindication to lung transplantation. We performed double lung transplantation in three cystic fibrosis patients with ongoing, and a fourth with recent treatment for Mycobacterium abscessus lung infection. Despite prolonged antibiotic courses and adjustment of immunosuppressive therapy the first three patients developed skin infection and abscesses. At follow-up after 1, 3, 5 and 7years respectively no patient had evidence of M abscessus infection and all had stable lung function. Lung transplantation in patients with M abscessus lung infection is feasible but may involve severe complications.

Prolonged Extracorporeal Membrane Oxygenation and Circulatory Support as Bridge to Lung Transplant

A 38-year-old man with progressive alveolitis secondary to polymyositis was treated for 52 days with venovenous and venoarterial extracorporeal membrane oxygenation as a bridge to bilateral lung transplantation. The patient survived, despite multiple complications, and is now back home with good pulmonary function. He is working part-time nearly 3 years post-transplant. This case shows that long-term extracorporeal lung assist is a viable but demanding alternative for bridging patients to pulmonary transplantation. This case also shows that right ventricular failure necessating conversion to veno-arterial assist does not necessarily predict right ventricular failure post-transplant.

One single dose of histidine–tryptophan–ketoglutarate solution gives equally good myocardial protection in elective mitral valve surgery as repetitive cold blood cardioplegia: A prospective randomized study

OBJECTIVES Histidine-tryptophan-ketoglutarate (HTK-Custodiol) cardioplegic solution is administered as one single dose for more than 2 hours of ischemia. No prospective randomized clinical study has compared the effects of HTK and cold blood cardioplegia on myocardial damage in elective mitral valve surgery. Thus, the main aim of the present study was to examine whether one single dose of cold antegrade HTK gives as good myocardial protection as repetitive antegrade cold blood cardioplegia in mitral valve surgery. METHODS Eighty consecutive patients undergoing elective isolated mitral valve surgery for mitral regurgitation, with or without ablation for atrial fibrillation, were included in the study and randomized to HTK or blood cardioplegia. Markers of myocardial injury (troponin-T and creatine kinase MB) were analyzed at baseline and 7 hours, 1 day, 2 days, and 3 days after surgery. RESULTS No significant difference in creatine kinase MB and troponin-T between HTK and blood cardioplegia groups was found at any time point. There was a significant correlation between ischemic time and markers of myocardial injury in the HTK group only and significantly more spontaneous ventricular fibrillation after release of crossclamping in the HTK group. CONCLUSIONS One single dose of antegrade cold HTK cardioplegic solution in elective mitral valve surgery protects the myocardium equally well as repetitive antegrade cold blood cardioplegia.

Compromised antioxidant status and persistent oxidative stress in lung transplant recipients.

Oxidative stress may be a key feature, and hence important determinant, of tissue injury and allograft rejection in lung transplant recipients. To investigate this, we determined the antioxidant status (urate, ascorbate, thiols and alpha-tocopherol) and lipid peroxidation status (malondialdehyde) in bronchoalveolar lavage (BAL) fluid and blood serum of 19 consecutive lung transplant recipients 2 weeks and 1, 2, 3, 6, and 12 months post-surgery. BAL fluid and blood samples from 23 control subjects and blood from 8 patients two days before transplantation were obtained for comparison. Before surgery, the antioxidant status of patients was poor as serum ascorbate and total thiol concentrations were significantly (p < 0.05) lower than control subjects. Two weeks post-surgery, ascorbate and total thiol concentrations were still low and urate concentrations had fallen compared to control subjects (p < 0.01). At this time, BAL fluid urate concentration was higher (p < 0.01), ascorbate concentration was lower (p < 0.01) and reduced glutathione concentrations were similar to control subjects. MDA, a product of lipid peroxidation, was higher (p < 0.01) in both BAL fluid and serum obtained from transplant patients compared to control subjects. During the first 12 months post-surgery, little improvement in antioxidant status or extent of lipid peroxidation was seen in transplant recipients. Regression analysis indicated no difference in serum or BAL fluid antioxidant status in patients with acute rejection compared to those without. In conclusion, lung transplant recipients have a compromised antioxidant status before surgery and it remains poor for at least the first year following the operation. In addition, these patients have elevated MDA concentrations in both their lung lining fluid and blood over most of this time. Oxidative stress is not, however, a sufficiently sensitive endpoint to predict tissue rejection in this group.

Inflammatory cells and activation markers in BAL during acute rejection and infection in lung transplant recipients: a prospective, longitudinal study

Acute rejection of the transplanted lung is a clinical problem, since it decreases graft survival and predisposes the patient to chronic rejection and obliterative bronchiolitis (OB). In an earlier study, we had indications that eosinophil cationic protein (ECP) from activated eosinophils and hyaluronan (HYA) from fibroblasts were associated with acute pulmonary rejection. This prospective longitudinal study was designed to investigate whether molecules from activated inflammatory cells in bronchoalveolar lavage (BAL) fluid could serve as clinically useful diagnostic markers for acute rejection. BAL fluid from 138 bronchoscopies performed in 10 single lung, four bilateral lung and five heart-lung transplant recipients were analysed. Nine patients were studied for a period of more than 1 yr (mean 13.4 months) after surgery. Differential cell counts were made from the BAL fluid. ECP, myeloperoxidase (MPO), HYA and interleukin-8 (IL-8) were used as indirect markers for activation and attraction of eosinophils, neutrophils and fibroblasts, respectively. Fifty four episodes of acute rejection were diagnosed. Two patients developed OB. Nine episodes of bacterial infection, 13 episodes of cytomegalovirus (CMV) pneumonitis, three of Pneumocystis carinii infection and one of respiratory syncytial virus (RSV) infection were diagnosed. The mean levels of ECP, MPO, HYA and IL-8 were all higher during rejection episodes, but differences were not statistically significant compared to no rejection, when the confounding factors of time, concomitant infection, and repeated measures in the same individual had been accounted for. We could not confirm that measurements of eosinophil cationic protein, myeloperoxidase, hyaluronan and interleukin-8 in bronchoalveolar lavage fluid can be used as diagnostic markers for acute rejection in the postoperative follow-up of lung transplant recipients.

Triclosan-coated sutures reduce surgical site infection after open vein harvesting in coronary artery bypass grafting patients: a randomized controlled trial †

OBJECTIVES The incidence of surgical site infection (SSI) after open vein harvesting in coronary artery bypass grafting (CABG) patients ranges in different studies between 2 and 20%. Triclosan is an antibacterial substance that reduces the growth of bacteria by inhibiting fatty acid synthesis. We hypothesized that wound closure with triclosan-coated sutures would reduce SSI after open vein harvesting. METHODS An investigator-initiated prospective randomized double-blind single-centre study was performed with 374 patients, randomized to subcutaneous and intracutaneous leg-wound closure with either triclosan-coated sutures (Vicryl Plus® and Monocryl Plus®, Ethicon, Somerville, NJ, USA) (n = 184) or identical sutures without triclosan (n = 190) from the same manufacturer. All patients were followed up after 30 days (clinical visit) and 60 days (telephone interview). Primary endpoint was SSI within 60 days after surgery according to the definition of Center for Disease Control. Predefined secondary endpoints included culture-proven and antibiotic-treated SSI. RESULTS The primary endpoint occurred in 23 patients (12.5%) with triclosan-coated sutures and in 38 patients (20.0%) in the group without triclosan (P = 0.0497, risk ratio 0.63, (95% confidence interval 0.39–1.00). Corresponding figures for culture-proven infections were 7.6 vs 12.1%, (P = 0.15), and for antibiotic-treated infections, 10.9 vs 18.4%, (P = 0.039). Staphylococcus aureus and coagulase-negative staphylococci were the most common pathogens in both groups. Insulin-treated diabetes and vein-harvesting time were associated with SSI after vein harvesting. CONCLUSIONS Leg-wound closure with triclosan-coated sutures in CABG patients reduces SSIs after open vein harvesting. (ClinicalTrials.gov number NCT01212315).

Butylated hydroxytoluene and N-acetylcysteine attenuates tumor necrosis factor-alpha (TNF-alpha) secretion and TNF-alpha mRNA expression in alveolar macrophages from human lung transplant recipients in vitro

BACKGROUND Tumor necrosis factor-alpha (TNF-alpha) is a polypeptide cytokine principally produced by macrophages/monocytes and commonly associated with inflammatory conditions. The present study was designed to investigate whether the antioxidants butylated hydroxytoluene (BHT) and N-acetylcysteine (NAC) modified TNF-alpha production in stimulated and unstimulated alveolar macrophages from lung transplant recipients in vitro. METHODS The effects of BHT and NAC on TNF-alpha production were studied both with and without lipopolysaccharide (LPS) activation of alveolar macrophages from bronchoalveolar lavage fluid. TNF-alpha was quantitated in cell culture medium using an enzyme-linked immunosorbent assay. TNF-alpha mRNA expression was analyzed by quantitative reverse transcription-polymerase chain reaction on total RNA extracted from the incubated alveolar macrophages. RESULTS In unstimulated alveolar macrophages, TNF-alpha levels were significantly reduced by incubation with BHT or NAC. When alveolar macrophages from patients with cytomegalovirus infection were incubated with BHT, TNF-alpha secretion was significantly lowered. A significant reduction of TNF-alpha levels in LPS-stimulated alveolar macrophages was obtained in the presence of BHT or NAC. Our data from quantitative reverse transcription-polymerase chain reaction showed that the observed decrease in protein levels of TNF-alpha was associated with a decrease in TNF-alpha mRNA expression. CONCLUSIONS Our results indicate that antioxidant treatment may be an effective step to lower the inflammatory process caused by cytomegalovirus infection or in endotoxin (LPS)-activated macrophages. The therapeutic use of antioxidant compounds could, therefore, be of interest in conditions such as lung transplantation, in which oxidative stress and inflammation can contribute significantly to the loss of allograft function.