Everolimus Versus Mycophenolate Mofetil De Novo After Lung Transplantation: A Prospective, Randomized, Open-Label Trial.

The role of mammalian target of rapamycin (mTOR) inhibitors in de novo immunosuppression after lung transplantation is not well defined. We compared Everolimus versus mycophenolate mofetil in an investigator-initiated single-center trial in Hannover, Germany. A total of 190 patients were randomly assigned 1:1 on day 28 posttransplantation to mycophenolate mofetil (MMF) or Everolimus combined with cyclosporine A (CsA) and steroids. Patients were followed up for 2 years. The primary endpoint was freedom from bronchiolitis obliterans syndrome (BOS). The secondary endpoints were incidence of acute rejections, infections, treatment failure and kidney function. BOS-free survival in intention-to-treat (ITT) analysis was similar in both groups (p = 0.174). The study protocol was completed by 51% of enrolled patients. The per-protocol analysis shows incidence of bronchiolitis obliterans syndrome (BOS): 1/43 in the Everolimus group and 8/54 in the MMF group (p = 0.041). Less biopsy-proven acute rejection (AR) (p = 0.005), cytomegalovirus (CMV) antigenemia (p = 0.005) and lower respiratory tract infection (p = 0.003) and no leucopenia were seen in the Everolimus group. The glomerular filtration rate (GFR) decreased in both groups about 50% within 6 months. Due to a high withdrawal rate, the study was underpowered to prove a difference in BOS-free survival. The dropout rate was more pronounced in the Everolimus group. Secondary endpoints indicate potential advantages of Everolimus-based protocols but also a potentially higher rate of drug-related serious adverse events.

Ex vivo evaluation of lungs from donation after cardiac death after recent cardiac surgery with cardiopulmonary bypass.

Lack of suitable donor lungs is still a major limitation of lung transplantation. Extended donor acceptance criteria combined with innovative assessment tools can be used to expand the number of suitable organs. We describe a successful transplantation of lungs retrieved from a donor who had undergone aortic root replacement 9 days before donation after cardiac death. The lungs were assessed using ex-vivo lung perfusion.

Pulmonary resection for airway complication after lung transplantation in a patient with cystic fibrosis: a case report.

We report a case of the interdisciplinary management of recurring bronchial stenosis after bilateral sequential single-lung transplantation (BSSLT) in a 35-year-old female with cystic fibrosis. Initial bronchoscopic therapy including balloon dilatation, stenting, and cryotherapy for granulation tissue overgrowth was unsuccessful in maintaining airway patency. In view of the persistent left lower lobe (LLL) atelectasis and fibrosis predisposing to recurrent infections, she was submitted for left lower lobectomy.

Incidence and impact of herpes simplex and cytomegalovirus detection in the respiratory tract after lung transplantation.

Herpesvirus infections cause morbidity in lung transplant recipients. The study was conducted to investigate the incidence and impact of herpes simplex virus (HSV) and cytomegalovirus (CMV) detection in the respiratory tract (RT) of lung and heart-lung transplant recipients (LTR) during the postoperative phase. In a prospective cohort study, 91 LTR having at least 1 nasopharyngeal swab (NPS) sent for virus diagnostics were monitored for CMV and HSV detection in NPS during their post-transplant hospital stay on cardiothoracic surgery wards (median 4 weeks) by direct immunofluorescence testing for HSV, virus culture, and CMV and HSV polymerase chain reaction (PCR). Bronchoalveolar lavages (BALs) were analyzed with the same protocol except that HSV PCR was only performed on request. Risk factor analysis for the outcome '90-day mortality' was performed. Fifteen LTR had virus detection in NPS (16.5%): 9 had CMV, 5 had HSV, and 1 had both CMV and HSV. Four of 84 LTR had CMV detection in BAL (4.8%). Absence of CMV detection in NPS had a negative predictive value of 98.8% for absence of CMV detection in BAL. HSV DNA detection in NPS, especially if detected within 8 days after transplantation, was associated with 90-day mortality. In conclusion, detection of herpesviruses in the RT was clinically relevant and frequent, despite antiviral prophylaxis.

Are metallic stents really safe? A long-term analysis in lung transplant recipients.

Airway complications affect 20% of all lung transplant recipients. Self-expandable metallic stents (SEMS) are one treatment option but their use in benign airway disorders is controversial. We studies the long-term safety of SEMS in lung transplant recipients. Between January 1998 and February 2008, all lung transplant recipients with SEMS were analysed retrospectively at a single centre. Complications were recorded until September 2008. In 65 (9.2%) out of 706 recipients, 111 (91% noncovered) bronchial SEMS were implanted a median (range) 133 (55-903) days after lung transplantation; follow-up was 777 (7-3.655) days. Clinical improvement was noted in 80% of recipients. The forced expiratory volume in 1 s increased by (mean+/-SD) 21+/-33%. Most frequent early complications were migration (3%) and mucus plugging (11%). No procedure-related deaths were noted. Re-stenosis occurred in 34 (52%) out of 65 recipients 85 (7-629) days after insertion. In multivariate analysis, stent insertion before post-operative day 90 was independently associated with an increased risk of re-stenosis (HR 3.29, 95% CI 1.50-7.18; p = 0.003). In 40% of recipients, new bacterial airway colonisation occurred after SEMS insertion. In SEMS patients, 5-yr survival was significantly lower than in the total cohort (60% versus 76%; p = 0.02). Late complications in lung transplant recipients treated with SEMS are frequent. The major problems are re-stenosis and airway colonisation.

Intentional ABO-incompatible lung transplantation.

We report on a case of intentional blood group incompatible lung transplantation. A blood group O cystic fibrosis patient was mechanically ventilated and put on interventional lung assist for severe respiratory decompensation. Since timely allocation of a blood group O donor lung was impossible, an AB deceased donor lung rescue allocation was accepted and the transplant performed using a pre-, peri- and postoperative antibody depletion protocol including plasmapheresis, ivIg administration, rituximab and immunoadsorption. Nine months after the transplant the patient is at home and well.

Restoration of blood flow and evaluation of corresponding angiogenic events by scanning electron microscopy after a single dose of VEGF in a model of peripheral vascular disease.

The angiogenic effect of vascular endothelial growth factor (VEGF) has typically been assessed by indirect methods, including microsphere injection and angiography. Here, we use 3-D scanning electron microscopy (SEM) to directly visualize patterns of angiogenesis after a single bolus administration of VEGF in a model of peripheral vascular ischemia. Hind limb ischemia was induced by subcutaneous turniquet implantation in adult Wistar rats. The control group (group A, n = 10) was left untreated, group B (n = 10) received a single dose of VEGF (50 microg) injected in the peroneus muscle. LASER Doppler was applied for blood flow measurements. Animals were sacrificed on day 14 after ischemia induction and vascular casting was performed. Angiogenetic events such as 'tiny lateral sprouts', arcus formations', confluences and the angle of sprouting were assessed by SEM. Significant capillary sprouting was observed in both groups. VEGF-treated limbs demonstrated higher degrees of capillary growth (P = 0.01) and flow recovery (P = 0.028). 3-D-SEM showed sprouts to be more frequent in group B. Tiny lateral sprouts, which always left the mother vessel at an angle of 90 degrees and which were of small diameter and lacked imprints of endothelial cell nuclei, were more frequent in the VEGF-treated group (P = 0.018). Arcus formation was significantly higher in the treated group (P = 0.02). We have developed a simple and effective experimental model of ischemia. For the study of angiogenic phenomena, 3-D imaging of the microvasculature offers a direct and conclusive method for the study of angiogenic events.

Case report: Kaposi's sarcoma: an unusual presentation.

Kaposi's sarcoma (KS) is the most common tumor associated with HIV-1 infection, affecting 30% of HIV-infected homosexual men before the advent of highly active antiretroviral therapy (HAART). In the era of HAART, the incidence of KS has markedly declined. KS usually presents with cutaneous lesions, but it may involve other organs, most commonly the pulmonary and gastrointestinal systems. Isolated pulmonary KS without cutaneous involvement is rare, although intrathoracic KS is seen in up to 75% of patients with KS. We describe an unusual case of a patient with AIDS and isolated endobronchial KS despite a normal arterial pO2, normal pulmonary function tests, no cutaneous KS, and normal chest computed tomographic findings.

H(2)O(2) signals 5-HT-induced ERK MAP kinase activation and mitogenesis of smooth muscle cells.

Our previous studies have shown that 5-hydroxytryptamine (5-HT) induces cellular hyperplasia/hypertrophy through protein tyrosine phosphorylation, rapid formation of superoxide (O(2)(-)), and extracellular signal-regulated kinase (ERK)1/ERK2 mitogen-activated protein (MAP) kinase activation. Intracellularly released O(2)(-) is rapidly dismuted by superoxide dismutase (SOD) to H(2)O(2), another possible cellular growth mediator. In the present study, we assessed whether H(2)O(2) participates in 5-HT-induced mitogenic signaling. Inactivation of cellular Cu/Zn SOD by copper-chelating agents inhibited 5-HT-induced DNA synthesis of bovine pulmonary artery smooth muscle cells (BPASMCs). Infection of BPASMCs with an adenovirus containing catalase inhibited both ERK1/ERK2 MAP kinase activation and DNA synthesis induced by 5-HT. Although we could not find evidence of p38 MAP kinase activation by 5-HT, SB-203580 and SB-202190, reported inhibitors of p38 MAP kinase, inhibited the 5-HT-induced growth of BPASMCs. However, these inhibitors also inhibited 5-HT-induced O(2)(-) release. Thus quenching of O(2)(-) may be their mechanism for inhibition of cellular growth unrelated to p38 MAP kinase inhibition. These data indicate that generation of O(2)(-) in BPASMCs in response to 5-HT is followed by an increase in intracellular H(2)O(2) that mediates 5-HT-induced mitogenesis through activation of ERK1/ERK2 but not of p38 MAP kinase.

Regulation of STAT3 by direct binding to the Rac1 GTPase.

The signal transducers and activators of transcription (STAT) transcription factors become phosphorylated on tyrosine and translocate to the nucleus after stimulation of cells with growth factors or cytokines. We show that the Rac1 guanosine triphosphatase can bind to and regulate STAT3 activity. Dominant negative Rac1 inhibited STAT3 activation by growth factors, whereas activated Rac1 stimulated STAT3 phosphorylation on both tyrosine and serine residues. Moreover, activated Rac1 formed a complex with STAT3 in mammalian cells. Yeast two-hybrid analysis indicated that STAT3 binds directly to active but not inactive Rac1 and that the interaction occurs via the effector domain. Rac1 may serve as an alternate mechanism for targeting STAT3 to tyrosine kinase signaling complexes.

Cross-species compatibility of intercellular adhesion molecule-1 (CD54) with its ligands.

BACKGROUND: The molecular interactions of intercellular adhesion molecule-1 (ICAM-1; CD54) are potentially important in several situations in the context of pig-to-human xenotransplantation. If porcine bone marrow is to be used for the induction of xenograft tolerance in humans, the role that has been suggested for ICAM-1 in the interactions of haematopoietic stem cells makes its cross-species compatibility important. Similarly, the potential role of ICAM-1 interactions in graft rejection makes it an important molecule to study. METHODS: An in vitro static cell-to-cell adhesion study was used to look at the successful interaction of ICAM-1 with its ligands across the pig-human species barrier in both directions. A second in vitro system, the standard long-term bone marrow culture (LT-BMC), was used to study the functional role of ICAM-1 in haematopoiesis. RESULTS: Human ICAM-1 was able to adhere to ligands on porcine cells, including one or more ligand that contains CD18. Conversely, human CD18-containing ligands mediated adherence to porcine cells. Using the long-term bone marrow culture system, there was no evidence that blocking the interactions of ICAM-1 inhibited hematopoiesis, either in the human-human or pig-human combinations of precursor cells and marrow stroma. CONCLUSIONS: ICAM-1 is able to interact with at least some of its ligands across the species barrier, in both pig-human and human-pig combinations. However, the interactions of ICAM-1 do not appear to be central to hematopoiesis, at least in the model system used.

Activation of the JAK-STAT pathway by reactive oxygen species.

Reactive oxygen species (ROS) play an important role in the pathogenesis of many human diseases, including the acute respiratory distress syndrome, Parkinson's disease, pulmonary fibrosis, and Alzheimer's disease. In mammalian cells, several genes known to be induced during the immediate early response to growth factors, including the protooncogenes c-fos and c-myc, have also been shown to be induced by ROS. We show that members of the STAT family of transcription factors, including STAT1 and STAT3, are activated in fibroblasts and A-431 carcinoma cells in response to H2O2. This activation occurs within 5 min, can be inhibited by antioxidants, and does not require protein synthesis. STAT activation in these cell lines is oxidant specific and does not occur in response to superoxide- or nitric oxide-generating stimuli. Buthionine sulfoximine, which depletes intracellular glutathione, also activates the STAT pathway. Moreover, H2O2 stimulates the activity of the known STAT kinases JAK2 and TYK2. Activation of STATs by platelet-derived growth factor (PDGF) is significantly inhibited by N-acetyl-L-cysteine and diphenylene iodonium, indicating that ROS production contributes to STAT activation in response to PDGF. These findings indicate that the JAK-STAT pathway responds to intracellular ROS and that PDGF uses ROS as a second messenger to regulate STAT activation.

Function of porcine adhesion molecules in a human marrow microenvironment.

BACKGROUND: One way to circumvent the need for chronic immunosuppression in solid organ xenografting may be to induce donor-specific tolerance using bone marrow transplantation. If this approach is to succeed in the pig-to-human species combination, pig marrow must be capable of maturing into relevant tolerance-inducing cells and replenishing itself in host human marrow. One possible barrier is adhesion molecule incompatibility. We have studied the compatibility across the pig-human species barrier of two well-characterized ligands known to be important in hematopoiesis, CD44 and very late antigen (VLA)-4. METHODS: In vitro long-term bone marrow cultures were studied in which the effects of blocking antibodies were assessed by measuring cell numbers and colony-forming units. RESULTS: The blocking of CD44 had a comparable inhibitory effect on the hematopoiesis of human and pig marrow, even if the latter was maintained on a human stromal layer. Both cellular proliferation and colony-forming activity were inhibited by anti-CD44 monoclonal antibody. By contrast, a significant difference was observed in VLA-4 usage by hematopoietic cells of the two species. Blocking VLA-4 markedly inhibited human hematopoietic cellular proliferation but had no effect on pig hematopoiesis, on either porcine or human stroma. CONCLUSIONS: The data suggest that the incompatibility of either CD44 or VLA-4 is unlikely to limit the efficiency of porcine hematopoiesis in a human marrow environment. However, the difference in VLA-4 utilization between these species raises the possibility that other interactions may be important for effective porcine hematopoiesis and that their failure to function between species may contribute to the poor function of porcine hematopoietic cells in primate marrow microenvironments.

Cross-species interaction of porcine and human integrins with their respective ligands: implications for xenogeneic tolerance induction.

BACKGROUND: Organ transplantation is limited by the number of available donors. One possible solution would be the use of pigs as organ donors. However, current immunosuppressive protocols cannot prevent rejection of these organs. If donor-specific tolerance toward porcine antigens could be induced in recipients, subsequent implantation of porcine organs would be possible without further immunosuppression. Induction of tolerance can be achieved with a bone marrow transplant if donor antigen-presenting cells successfully differentiate in the recipient thymus to induce deletion of donor-reactive host cells. Migration of porcine progenitor cells to the host marrow and thymus and differentiation into tolerance-inducing antigen-presenting cells is likely to require successful interaction of porcine adhesion molecules with human ligands. In this study, we investigated whether very late antigen (VLA)4 and VLA-6 integrins, which play important roles in homing and differentiation of hematopoietic progenitor cells, function across the pig-to-human species barrier. METHODS: Static cell-to-cell and cell-to-extracellular matrix protein adhesion assays were used to examine the cross-species interaction of porcine adhesion molecules with human ligands. RESULTS: Our studies show that porcine cells adhere to various human endothelial cell monolayers and extracellular matrix proteins and demonstrate that porcine VLA-4 and VLA-6 appear to be fully cross-reactive to the human ligands vascular cell adhesion molecule-1 and laminin, respectively. CONCLUSIONS: It is likely that porcine hematopoietic progenitor cells will be able to successfully employ pVLA-4- and pVLA-6-human ligand interactions in a pig-to-human bone marrow transplantation model in order to induce donor-specific tolerance.

Two natal maxillary molars. Report of a case.

A 20-day-old black male infant with two rare posterior natal teeth was referred for examination and care. Oral radiographs suggested that the teeth were the right and left maxillary primary molars. The hypermobile teeth and associated suspicious soft tissue masses were removed. Histologic examination revealed irregular tooth structures and infiltrate consistent with inflamed dental follicles.