Comparing everolimus-based immunosuppression with reduction or withdrawal of calcineurin inhibitor reduction from six months after heart transplantation: the randomized MANDELA study

In the 12-month, open-label MANDELA study, patients were randomized at month 6 after heart transplantation to (i) convert to calcineurin inhibitor (CNI)-free immunosuppression with everolimus (EVR), mycophenolic acid and steroids (CNI-free, n=71), or to (ii) continue reduced-exposure CNI, with EVR and steroids (EVR/redCNI, n=74). Tacrolimus was administered in 48.8% of EVR/redCNI patients and 52.6% of CNI-free patients at radomization. Both strategies improved and stabilized renal function based on the primary endpoint (estimated GFR at month 18 post-transplant post-randomization) with superiority of the CNI-free group versus EVR/redCNI : mean 64.1mL/min/1.73m2 versus 52.9mL/min/1.73m2 ; difference +11.3mL/min/1.73m2 (p<0.001). By month 18, estimated GFR had increased by ≥10mL/min/1.732 in 31.8% and 55.2% of EVR/redCNI and CNI-free patients, respectively, and by ≥25 mL/min/1.73m2 in 4.5% and 20.9%. Rates of biopsy-proven acute rejection (BPAR) were 6.8% and 21.1%; all cases were without hemodynamic compromise. BPAR was less frequent with EVR/redCNI versus the CNI-free regimen (p=0.015); 6/15 episodes in CNI-free patients occurred with EVR concentration <5ng/mL. Rates of adverse events and associated discontinuations were comparable EVR/redCNI from month 6 achieved stable renal function with infrequent BPAR. One-year renal function can be improved by early conversion to EVR-based CNI-free therapy but requires close EVR monitoring. This article is protected by copyright. All rights reserved.

Synergism of imatinib, vatalanib and everolimus in the prevention of chronic lung allograft rejection after lung transplantation (LTx) in rats

Chronic lung allograft dysfunction (CLAD) still remains a major drawback in the outcome following lung transplantation (LTx). New therapeutic strategies are warranted. Growth factors and their receptors like platelet-derived growth factor-receptor (PDGFR) and vascular endothelial growth factor-receptor (VEGFR), may play a crucial role in the development of CLAD, especially bronchiolitis obliterans (BO) and vasculopathy. In this study, we used an orthotopic left lung transplantation model from Fischer (F344) to Wystar Kyoto (WKY) rats to investigate the effect of the receptor tyrosine kinase inhibitor (RTKI) vatalanib alone, the dual combination of vatalanib and imatinib and a triple therapy consisting of vatalanib, imatinib and the mammalian target of rapamycin inhibitor (mTORI) everolimus on the development of CLAD after LTx in rats. With this trial we demonstrated that monotherapy with vatalanib attenuated mild and severe chronic vascular rejection, whereas dual therapy (vatalanib and imatinib) after LTx also showed a significant reduction of chronic bronchiolar rejection and interstitial fibrosis. By adding everolimus, the effect of vatalanib and imatinib could additionally be increased. In conclusion, the combination of mTORI and RTKIs might be a possible strategy in the prevention of CLAD and BO.

The activity of nintedanib in an animal model of allogenic left lung transplantation resembling aspects of allograft rejection

AIM OF THE STUDY

The prevention and treatment of chronic lung allograft dysfunction (CLAD) after lung transplantation (LTx) remain unsatisfactory. Growth factors may play an important role in the development of CLAD. This study evaluated the effects of nintedanib, a receptor tyrosine kinase inhibitor, in the treatment of CLAD after experimental LTx.

MATERIALS AND METHODS

A rat model of left lung allo-transplantation (Fisher 344 to Wistar Kyoto) was used to evaluate the effect of nintedanib (50 mg/kg per day) on the development of CLAD. Therapy with nintedanib began 2 days before LTx and ended on postoperative day (POD) 20 (n = 6) or 60 (n = 6). Nontreated animals who underwent LTx (n = 12) were used as controls, whereas naïve lungs (n = 24) served as reference for physiological healthy organs without transplantation damage or medical effects. Acute and chronic rejection were evaluated on POD 20 and 60, respectively.

RESULTS

Immunohistologic analysis showed a decrease in growth factors/receptors on POD 60 (nintedanib-treated vs. nontreated controls: platelet-derived growth factor (PDGF) A: [P ≤ 0.001]; PDGF receptor-α: [P ≤ 0.001]; vascular endothelial growth factor (VEGF) A: [P ≤ 0.001]; VEGF receptor-2: [P ≤ 0.001]). However, no reductions in fibrotic changes were observed in nintedanib-treated allografts compared with nontreated allografts. Although nintedanib treatment started before LTx none of the animals showed impaired wound healing. No dehiscence of the sutures of the bronchus, vessels or skin, or stenosis of the bronchus was found.

CONCLUSION

In conclusion, while nintedanib reduced the expression of growth factors/receptors in a rat LTx model, a reduction in fibrotic alterations was not observed at POD 60.

Impact of Elevated Donor Troponin I as Predictor of Adverse Outcome in Adult Heart Transplantation: A Single-center Experience

BACKGROUND

Due to globally increasing donor organ shortage, investigation of previously described risk factors for utilizing marginal donor hearts is needed. The aim of this study was to determine the impact of elevated donor serum troponin I (TnI) levels on outcome after heart transplantation (HTx).

METHODS

Between January 1996 and August 2013, 161 patients were reviewed for donor TnI serum levels (>0.3 ng/mL was considered elevated), postoperative outcome parameters, 30-day mortality, and 1-, 3-, and 5-year survival.

RESULTS

TnI levels were elevated in 45 (28.0%) donors. Recipients of hearts with elevated TnI had higher incidence of postoperative systolic dysfunction, prolonged inotropic support, prolonged mechanical ventilation, and longer intensive care unit (ICU) stay (p < 0.001). This group had higher 30-day mortality (22.2% vs 8.6%, p = 0.03) and lower 1-, 3-, and 5-year survival (56%, 53%, and 50% versus 82%, 76%, and 69%, p = 0.032). Elevated TnI was the only independent risk factor for 30-day mortality (odds ratio [OR] 3.63, 95% confidence interval [CI] 1.28-10.27, p = 0.015).

CONCLUSIONS

Elevated donor TnI serum concentration seems to be a marker for adverse outcome and increased short- and long-term mortality after HTx. Nevertheless, many other perioperative variables and parameters can be associated with outcome.

Impact of Elevated Donor Troponin I as Predictor of Adverse Outcome in Adult Heart Transplantation: A Single-center Experience

BACKGROUND

Due to globally increasing donor organ shortage, investigation of previously described risk factors for utilizing marginal donor hearts is needed. The aim of this study was to determine the impact of elevated donor serum troponin I (TnI) levels on outcome after heart transplantation (HTx).

METHODS

Between January 1996 and August 2013, 161 patients were reviewed for donor TnI serum levels (>0.3 ng/mL was considered elevated), postoperative outcome parameters, 30-day mortality, and 1-, 3-, and 5-year survival.

RESULTS

TnI levels were elevated in 45 (28.0%) donors. Recipients of hearts with elevated TnI had higher incidence of postoperative systolic dysfunction, prolonged inotropic support, prolonged mechanical ventilation, and longer intensive care unit (ICU) stay (p < 0.001). This group had higher 30-day mortality (22.2% vs 8.6%, p = 0.03) and lower 1-, 3-, and 5-year survival (56%, 53%, and 50% versus 82%, 76%, and 69%, p = 0.032). Elevated TnI was the only independent risk factor for 30-day mortality (odds ratio [OR] 3.63, 95% confidence interval [CI] 1.28-10.27, p = 0.015).

CONCLUSIONS

Elevated donor TnI serum concentration seems to be a marker for adverse outcome and increased short- and long-term mortality after HTx. Nevertheless, many other perioperative variables and parameters can be associated with outcome.

Basophils Trigger Fibroblast Activation in Cardiac Allograft Fibrosis Development

Fibrosis is a major component of chronic cardiac allograft rejection. Although several cell types are able to produce collagen, resident (donor-derived) fibroblasts are mainly responsible for excessive production of extracellular matrix proteins. It is currently unclear which cells regulate production of connective tissue elements in allograft fibrosis and how basophils, as potential producers of profibrotic cytokines, are involved this process. We studied this question in a fully MHC-mismatched model of heart transplantation with transient depletion of CD4(+) T cells to largely prevent acute rejection. The model is characterized by myocardial infiltration of leukocytes and development of interstitial fibrosis and allograft vasculopathy. Using depletion of basophils, IL-4-deficient recipients and IL-4 receptor-deficient grafts, we showed that basophils and IL-4 play crucial roles in activation of fibroblasts and development of fibrotic organ remodeling. In the absence of CD4(+) T cells, basophils are the predominant source of IL-4 in the graft and contribute to expansion of myofibroblasts, interstitial deposition of collagen and development of allograft vasculopathy. Our results indicated that basophils trigger the production of various connective tissue elements by myofibroblasts. Basophil-derived IL-4 may be an attractive target for treatment of chronic allograft rejection.

Protective function of pirfenidone and everolimus on the development of chronic allograft rejection after experimental lung transplantation

Long-term survival of lung allografts is limited by chronic rejection (CR). Oxidative stress (OxS) plays a central role in the development of CR. We investigated the influence of pirfenidone (alone or in combination with everolimus) on OxS and CR. A rat model of left lung allo-transplantation (F344-to-WKY) was used to evaluate the effects of pirfenidone alone [0,85% in chow from postoperative day (POD) -3 to 20/60] and in combination with everolimus [2,5 mg/kg bw daily from POD 7 to 20/60]. Allografts of non-treated animals, everolimus treated animals and right, non-transplanted lungs were used as references. Immunohistology of myeloperoxidase (MPO), haemoxygenase-1 (HO-1), iron and platelet-derived-growth-factor-receptor-alpha (PDGFR-a) were performed. On POD 20, all groups showed severe acute rejection (ISHLT A3-4/B1R-B2R). Groups treated with pirfenidone showed a lower interstitial inflammatory infiltration and a lower participation of highly fibrotic degenerated vessels (ISHLT-D2R). In the long term follow up (POD 60), pirfenidone alone significantly reduced chronic airway rejection (ISHLT-C; p≤0.05), interstitial fibrosis (IF; p≤0.05), content of collagen (p≤0.05), expression of PDGFR-a (p≤0.05) and the deposition of iron (p≤0.05). All groups treated with pirfenidone showed a high expression of the cytoprotective enzyme HO-1 (p≤0.05). The additional application of everolimus resulted in a significant decrease of chronic airway rejection (ISHLT-C; p≤0.05), vasculopathy (ISHLT; p≤0.05) and IF (p≤0.05). In conclusion, early application of pirfenidone inhibited the progression of CR by its anti-fibrotic and anti-oxidative properties. The additional application of an m-TOR-inhibitor increased the anti-fibrotic effects of pirfenidone which resulted in a reduction of CR after experimental LTx.

Minimized extracorporeal circulation is improving outcome of coronary artery bypass surgery in the elderly

Advanced age is a known risk factor for morbidity and mortality after coronary artery bypass grafting (CABG). Minimized extracorporeal circulation (MECC) has been shown to reduce the negative effects associated with conventional extracorporeal circulation (CECC). This trial assesses the impact of MECC on the outcome of elderly patients undergoing CABG. Eight hundred and seventy-five patients (mean age 78.35 years) underwent isolated CABG using CECC (n=345) or MECC (n=530). The MECC group had a significantly shorter extracorporeal circulation time (ECCT), cross-clamp time and reperfusion time and lower transfusion needs. Postoperatively, these patients required significantly less inotropic support, fewer blood transfusions, less postoperative hemodialysis and developed less delirium compared to CECC patients. In the MECC group, intensive care unit (ICU) stay was significantly shorter and 30-day mortality was significantly reduced [2.6% versus 7.8%; p<0.001]. In conclusion, MECC improves outcome in elderly patients undergoing CABG surgery.

Everolimus's influence on persistent acute rejection after experimental lung transplantation

BACKGROUND

In lung transplantation, acute rejection episodes increase the risk of chronic rejection. Therefore treatment of acute rejection needs to be optimized for better long-term outcome of lung-transplantation and patient survival.

OBJECTIVES

The aim was to verify whether an inhibitor of the mammalian target of rapamycin (Everolimus) contained the extent of persistent acute rejection after left lung allo-transplantation in rats.

MATERIAL AND METHODS

Rats (F344-to-WKY) with a high grade of acute rejection were treated with methylprednisolone (10mg/kg, postoperative days 14-16) alone or in combination with everolimus (2.5 mg/kg, postoperative days 14-30). The rats were killed on postoperative day 20 and 30. Infiltration of inflammatory cells (ED1, CD11a, CD18) and activation of endothelial cells (ICAM-1) were measured by immunohistochemistry

RESULTS

Everolimus treatment significantly reduced the number of ICAM-1 positive small vessels (66%; p<0.05) and suppressed the infiltration of leucocytes (CD11a (64%), CD18 (42%); p<0.05) and macrophages (ED1; 22%) in the allografts on POD 30. Despite this clear anti-inflammatory effects, lung allografts still showed severe acute vascular rejection in combination with high grade small airway inflammation.

CONCLUSIONS

The shown anti-inflammatory effects of Everolimus could not delay the progression of acute rejection in rat lung allografts.

Inhibition of innate co-receptor TREM-1 signaling reduces CD4(+) T cell activation and prolongs cardiac allograft survival

The innate receptor "triggering-receptor-expressed-on-myeloid-cells-1" (TREM-1) enhances downstream signaling of "pattern recognition receptor" (PRR) molecules implicated in inflammatory responses. However the mechanistic role of TREM-1 in chronic heart rejection has yet to be elucidated. We examined the effect of TREM-1(+) antigen-presenting cells (APC) on alloreactive CD4(+) lymphocytes. Bm12 donor hearts were transplanted into wild-type MHC-class-II-mismatched C57BL/6J recipient mice. Progressive allograft rejection of bm12-donor hearts with decreased organ function, severe vasculopathy and allograft fibrosis was evident within 4 weeks. TREM-1(+) CD11b(+) MHC-II(+) F4/80(+) CCR2(+) APC and IFNγ-producing CD4(+) cells were detected during chronic rejection. Peptide inhibition of TREM-1 attenuated graft vasculopathy, reduced graft-infiltrating leukocytes and prolonged allograft survival, while being accompanied by sustained low levels of CD4(+) and CD8(+) cell infiltration. Remarkably, temporary inhibition of TREM-1 during early immune activation was sufficient for long-term allograft survival. Mechanistically, TREM-1 inhibition leads to reduced differentiation and proliferation of IFNγ-producing Th1 cells. In conclusion, TREM-1 influences chronic heart rejection by regulating the infiltration and differentiation of CD4(+) lymphocytes.

Pharmacokinetics of a self-microemulsifying drug delivery system of tacrolimus

This study evaluated the pharmacokinetics of tacrolimus (Tac) in a novel self-microemulsifying drug delivery system (SMEDDS) for improved oral administration. SMEDDS Tac consisted of ethyl oleate as the oily phase, Solutol HS 15 as the surfactant and glycofurol as the co-surfactant and contained 0.5mg/mL tacrolimus. Blood and tissue concentrations of tacrolimus from two study groups (oral application of SMEDDS Tac and Prograf®) were determined using ELISA technique following tacrolimus administration in rats. There was no difference between area under the whole blood concentration-time curve in the SEDDM Tac group and the Prograf® group. Maximum concentrations of the drug were three times higher (P<0.05) in the SEDDM Tac group accompanied by a 3-fold earlier peak time. Elimination half-life was significantly lower in the SEDDM Tac group. Application of SMEDDS Tac increased tissue accumulation. Already after 15 min, Tac levels of small intestine, liver, kidney, spleen, heart and bone marrow were significantly higher in the SMEDDS Tac group than in the Prograf® group (P<0.05). However, the Tac concentration in the kidney was significantly lower in the SMEDDS Tac group. Formulation of SMEDDS did not affect blood-brain barrier function. The SMEDDS is a potentially useful method for a local delivery of Tac to target organs. The selection of the optimum SMEDDS Tac composition might have advantage as an alternative oral dosage form for Tac.

Synergism of imatinib mesylate and everolimus in attenuation of bronchiolitis obliterans after rat LTX

Bronchiolitis obliterans (BO) is a progressive and fatal disease after lung transplantation (LTX). Dysregulated growth factor-induced proliferation of myofibroblasts seems to be responsible for the development of BO. The aim was to confirm the efficacy of both inhibitors of receptor tyrosine kinases (RTKI) and of mammalian target of rapamycin (mTORI) after rat LTX. We used a rat model of left lung allo-transplantation (F344-to-WKY) to evaluate the effect of imatinib (RTKI; 20 mg/kg/day; postoperative day (POD) 0-100) alone or in combination with everolimus (mTORI; 2.5 mg/kg/day; POD 14-100). Non-treated animals were the reference. In non-treated rats, acute rejection (AR) peaked between POD 20 and 30 (19/19) and ended in chronic rejection (CR) on POD 60/100 (12/12). Imatinib alone did not prevent AR (6/6), but attenuated the degree of degenerated bronchioles on POD 30 (non-treated, 57%; imatinib, 4%), and increased the allografts free of CR on POD 60/100 (3/12). A combination of imatinib and everolimus significantly reduced AR, attenuated fibrotic degenerated bronchioles (5%) and vessels (non-treated, 24%; combination therapy, 11%) on POD 30, and reduced fibrotic degenerated vessels (non-treated, 97%; combination therapy, 43%) and bronchioles (non-treated, 88%; combination therapy, 34%) on POD 60/100. Fifty percent of the animals were completely free of BO and vasculopathy. In conclusion, co-application of RTKI and mTORI attenuated the development of BO and vasculopathy. Thus, imatinib might be an interesting therapeutic approach after LTX.

Relevance of maintenance triple-drug immunosuppression to bridle the amplification of rat cytomegalovirus infection after experimental lung transplantation

Immunosuppressive therapy required to treat rejection after lung transplantation (LTx) contributes significantly to the pathogenesis of cytomegalovirus (CMV) infection and disease. In a weak allogeneic left LTx model in the rat (Fisher 344 [F344] to Wistar Kyoto [WKY] rats) we analyzed the influence of acute CMV infection on postoperative day (POD) 3, with application of standard triple-drug immunosuppression (TD-IS) (cyclosporin A, azathioprine, prednisolone) on late outcome after LTx. Native right lungs and syngeneic grafts (WKY to WKY) served as controls. Rats were sacrificed on POD 15, 30, 60, and 100. TD-IS completely prevented acute and chronic rejection in non-infected rats. Allografts of CMV-infected rats treated with TD-IS showed only mild perivascular infiltrations in 6/10 rats (POD 15 and 30), which persisted up to POD 100 in 4/10 rats. In the long-term course, mild isolated interstitial and alveolar changes were found in 40% of these animals. In conclusion, rat CMV infection partially neutralized the immunosuppressive effect of TD-IS. However, an amplification of CMV infection under TD-IS can be controlled and does not result in fatal outcome.

Temporary percutaneous right ventricular support using a centrifugal pump in patients with postoperative acute refractory right ventricular failure after left ventricular assist device implantation

OBJECTIVE

Acute right ventricular (RV) failure is a life-threatening condition with a poor prognosis, and sometimes the use of mechanical circulatory support is inevitable. In this article, we describe our experience using a centrifugal pump as a temporary percutaneous right ventricular assist device (RVAD) in patients with postoperative acute refractory RV failure after left ventricular assist device (LVAD) implantation.

METHODS

We retrospectively reviewed eight consecutive patients with acute RV failure who underwent temporary percutaneous RVAD implantation using a centrifugal pump after LVAD implantation between April 2008 and February 2011. A Dacron graft was attached to the main pulmonary artery and passed through a subxiphoid exit, where the outflow cannula was inserted. The inflow cannula was percutaneously cannulated using Seldinger's technique in the femoral vein. The chest was definitely closed. The technique allowed bedside removal, avoiding chest re-opening.

RESULTS

The median patient age was 52 years (range: 41-58). The median duration of support was 14 days (range: 12-14). RV systolic function improved; central venous pressure and mean pulmonary artery pressure decreased significantly after RVAD support. In three patients, an oxygenator was integrated into the RVAD due to impaired pulmonary function. Six patients were successfully weaned. Five patients survived to hospital discharge. Technical problems or serious complications concerning decannulation were not observed.

CONCLUSION

This report suggests that implantation of temporary percutaneous RVAD using a centrifugal pump is a safe alternative in the treatment of postoperative acute refractory RV failure. Ease of device implantation, weaning, explantation, and limited number of complications justify a liberal use.

Suppression of bronchiolitis obliterans in allogeneic rat lung transplantation--effectiveness of everolimus

BACKGROUND

Chronic rejection (CR) after lung transplantation (LTX) manifests pathologically by fibrotic airway remodelling and bronchiolitis obliterans (BO). The role of the mammalian target of rapamycin inhibitor everolimus in preventing this process is poorly understood.

METHODS

A rat model of left lung allo-transplantation (Fisher 344 to Wistar Kyoto) was used to analyze the effect of everolimus (2.5 mg/kg/day) on the development of CR. Drug therapy began on postoperative day (POD) 0, 7 and 14 characterizing different grade of acute rejection (AR) of the allograft before drug treatment.

RESULTS

Non-treated recipients developed severe acute rejection (AR) and first signs of CR on POD 20 and a pronounced CR on POD 60. On POD 20, only application of everolimus from POD 0 to 60 significantly reduced acute inflammatory infiltration (p<0.001). Independent of treatment scheme, everolimus suppressed the development of early signs of chronic alterations (POD 20). However, neither early (POD 7-60) nor late (POD 14-60) application of everolimus affected the progression of CR (POD 60). Only its initial treatment (POD 0-60) inhibited the development of BO and vasculopathy (p<0.001). An additional finding was a decrease in body weight after drug application.

CONCLUSION

The effectiveness of everolimus after rat LTX depended on the grade of inflammation of the allograft before initiation of drug treatment. Only allografts with no or low grade AR benefit from long-term treatment with everolilmus in the prevention of BO after LTX. It could be speculated that conversion to an everolimus-based immunosuppression after LTX might only be successful in patients free of BO.

Ventricular assist device implantation in patients on percutaneous extracorporeal life support without switching to conventional cardiopulmonary bypass system

OBJECTIVES

Ventricular assist device (VAD) implantation using cardiopulmonary bypass (CPB) is an established procedure. However, the well-described complications of CPB may exacerbate multiple organ failure and increase blood product transfusions especially in end-stage heart failure patients.

METHODS

We describe our successful experience in six consecutive patients with profound cardiogenic shock, who were provided on an emergency basis with a percutaneous extracorporeal life support (ECLS) system via the peripheral vessels. After stabilization, a VAD was implanted using ECLS without switching to a conventional CPB system to reduce its side effects. We compared the data with those of 11 patients in whom the VAD was placed with the aid of an additional CPB system.

RESULTS

The six patients demonstrated a shorter duration of operating room time compared with the patients requiring CPB for device placement. During and after surgery, blood loss and blood product transfusions were lower in these patients. The need for mechanical ventilation and inotropic support was shorter and the survival rate (100% at 30 days, 83.3% at 3 months and 83.3% at 6 months) was higher when compared with patients who were operated upon with CPB. Two patients were successfully bridged to transplantation. One patient died due to cerebral bleeding after 7 weeks.

CONCLUSIONS

Our experience suggests that VAD implantation using percutaneous ECLS without switching to conventional CPB is a safe alternative in the bridge to bridge concept, especially in high-risk patients with cardiogenic shock who would benefit from the avoidance of the adverse sequels associated with conventional CPB.

Successful use of a percutaneous miniaturized extracorporeal life support system as a bridge and assistance to left ventricular assist device implantation in a patient with severe refractory cardiogenic shock

We present a 51-year-old man with cardiogenic shock in whom a percutaneous extracorporeal life support system (ECLS) was inserted to restore cardiopulmonary stability. After successful stabilization, a left ventricular assist device was implanted, using the ECLS without switching to a conventional cardiopulmonary bypass system to reduce its side effects.

Influence of intensified medical treatment and organ allocation on outcome of transplant candidates

BACKGROUND

To test how the organization of a pre-transplant clinic and changes in organ allocation modus influence the survival of potential transplant candidates, the survival of patients referred for transplant evaluation between 4/93 and 4/96 (group A) was compared to that of patients referred from 5/96 to 7/00(group B).

METHODS

After screening for transplant indication, group A was followed by the referring physician up to transplantation or 3-month reevaluation. Group B was closely followed by a specialized heart-failure clinic. Group A was transplanted according to Eurotransplant criteria, with waiting time being the strongest priority criterion. Due to an allocation partnership off our transplant centers, group B could be transplanted according to medical urgency regardless of waiting time.

RESULTS

Overall one-year survival after referral was 69.8% for group A vs. 91 %for group B (p <0.0001). Transplantation within 1 year was required in more group A than group B patients (34% vs. 23%)with worse one-year post-transplant survival in group A (82%vs. 93%).

CONCLUSIONS

Intensified treatment by a specialized heart failure program and an allocation system that allows for preferred transplantation of the 'sickest' patient improved over-all survival of transplant candidates and reduced the percentage of patients requiring transplantation.

A case of fetal parvovirus B19 myocarditis, terminal cardiac heart failure, and perinatal heart transplantation

We report a case of fetal cardiomegaly secondary to myocarditis as a result of intrauterine parvovirus B19 infection. The fetus was delivered through caesarean section because of increasing deterioration of cardiac function at 33 + 3 weeks with reverse flow in the ductus venosus. Four weeks later, a cardiac transplantation was carried out because of therapy-resistant dilative cardiomyopathy. This case shows that fetal parvovirus B19 infection may occur without anemia and myocarditis and does not always result in spontaneous reformation of a dilated heart and normal recovery. It may become the determining prognostic factor for the child.

Immunoglobulin A and secretory immunoglobulin A in the bronchoalveolar lavage from patients after lung transplantation

Secretory immunoglobulin A (sIgA) is the most important Ig on mucosal surfaces. In bronchoalveolar lavage (BAL) fluid, sIgA is mainly produced by bronchus-associated lymphoid tissue (BALT). The presence of pre-formed antibodies against donor tissue in kidney transplantation is associated with hyperacute rejection, indicating a humoral (antibody-mediated) reaction. In heart and liver transplantation, humoral rejection has also been documented. The goal of this study was to evaluate the role of IgA in patients after lung transplantation. An enzyme-linked immunosorbent assay was established to determine the levels of sIgA, IgA, and total protein in the lavage. IgA and sIgA were both detectable in BAL from transplanted lungs. IgA and sIgA levels were both higher during episodes of infection than during episodes of rejection or during the control episodes. The level of IgA during episodes of rejection equaled the level of IgA during the control episodes. The level of sIgA was significantly decreased during episodes of acute rejection (1.8 +/- 1.0 microg/mL) when compared with the control (7.2 +/- 1.0 microg/mL; p = 0.013). This study demonstrates that BALT retains the ability to produce Ig even after lung transplantation. The levels of IgA and sIgA and their ratio do not contribute to the differentiation between rejection and infection in lung-transplanted patients.

Topical amphotericin B application in severe bronchial aspergillosis after lung transplantation: report of experiences in 3 cases

Ulcerative tracheobronchial aspergillosis after lung transplantation (ltx) may lead to bronchial-pulmonary artery fistula that results in fatal bleeding. We report our early experience with combined systemic, aerolized and topical application of amphotericin B in 3 cases of bronchial aspergillosis after ltx. Two patients are still alive, but 1 died of bleeding from a fistula between the left upper lobe bronchus and the pulmonary artery. Aspergillosis in the second patient resolved with minimal stenosis of the left main and the left upper lobe bronchus, and the third patient developed an anastomotic stenosis that was successfully dilated.

Detection of CMV pneumonitis after lung transplantation using PCR of DNA from bronchoalveolar lavage cells

BACKGROUND

Cytomegalovirus (CMV) is known as a common pathogen causing infections after lung transplantation. Rapid diagnosis of CMV infection is important for the initiation of a specific treatment.

OBJECTIVE

Evaluation of methods for the rapid diagnosis of CMV pneumonitis.

METHODS

The detection rates of CMV DNA in bronchoalveolar lavage (BAL) and bronchial brushes by polymerase chain reaction (PCR), of viral antigens (p52 and IE1) in BAL and of pp65 antigen in peripheral blood leukocytes were compared to the clinical status after lung transplantation. In 28 patients, 105 BAL, 96 blood samples and 14 brushes were analyzed.

RESULTS

In 6 patients, a total of eight episodes of CMV pneumonitis occurred. Five of the 6 with positive CMV antigens in BAL (p52 or IE1) showed signs of CMV pneumonitis. All episodes of CMV pneumonitis were detected by the PCR of BAL cells. Fourteen samples positive for CMV pp65 antigen in blood were negative in BAL PCR. In these cases, no clinical signs of pulmonary CMV infection occurred. Overall sensitivity, specificity, and positive and negative predictive values for the detection of CMV pneumonitis by PCR of BAL cells were 100, 98.9, 88.9 and 100%, respectively. In brush samples, PCR did not provide additional information to the results of the PCR of BAL cells.

CONCLUSIONS

PCR of DNA from BAL cells is suitable for reliable and rapid detection of CMV pneumonitis.

C1-esterase inhibitor in graft failure after lung transplantation

Graft failure after lung transplantation may occur immediately after transplantation due to reperfusion injury or later due to rejection and infection. Although the pathological mechanisms are not completely known, the clinical findings are similar to the adult respiratory distress syndrome. In this condition, the blood coagulation contact system and the complement system are activated, leading to a capillary leak syndrome. Activation of the contact as well as the complement system is regulated by a common inhibitor, C1-esterase inhibitor (C1-INH). We report on two patients who received high doses of C1-INH for 2 days during graft failure either due to reperfusion injury immediately after transplantation or due to an acute rejection 2 months after double-lung transplantation. In both cases of graft failure, a capillary leak syndrome occurred with pleural effusions of 7 l to more than 10 l per day. In case 1 disturbance of gas exchange during severe reperfusion injury could not be treated effectively with other treatment modalities like nitric oxide ventilation or surfactant administration. With the use of C1-INH, pleural effusions reduced within 12 h, leading to normal graft function within 4 days. In the second recipient, acute rejection forced the use of extracorporeal membrane oxygenation (ECMO) within 24 h despite immunosuppressive therapy. After administration of C1-INH, pleural effusions reduced from 19 l per day to 300 ml within 3 days of treatment. ECMO was discontinued after C1-INH treatment and the patient extubated 2 weeks later. This experience indicates that C1-INH may play a role in the management of capillary leak syndrome after lung transplantation.

Surfactant replacement in reperfusion injury after clinical lung transplantation

BACKGROUND

Reperfusion injury remains a significant risk factor in the immediate postoperative course after lung transplantation. We report on our initial clinical experience of surfactant replacement in reperfusion injury after clinical lung transplantation.

METHODS AND RESULTS

In 31 consecutive patients, lung (8 single lung, 16 bilateral lung) or heart-lung (7) transplantation was performed. In 6 patients, severe reperfusion injury developed and was treated with continuously nebulized surfactant. Compliance of the allograft increased 40 +/- 25 % within 3 h following treatment with surfactant. Alveolar arterial oxygen gradient decreased by 23 +/- 11 % after 3 h and by 35 +/- 20 % after 6 h. Normal graft function was reestablished within 1-3 days after transplantation. All treated recipients were extubated until the 6th postoperative day. The 30-day mortality for the 31 recipients was 3.3 %, the 1-year survival 84 %.

CONCLUSIONS

Surfactant replacement may become a clinical method for treatment of reperfusion injury after lung transplantation.

Development of obliterative bronchiolitis after allogeneic rat lung transplantation: implication of acute rejection and the time point of treatment

BACKGROUND

Chronic allograft failure represents the major cause of late morbidity and mortality after solid organ transplantation. Despite the pathological and clinical changes of this disease being well-described, the etiology and the causative factors are still under discussion. Several clinical, as well experimental studies, emphasize the significance of acute rejection. In rat model of left lung allo-transplantation (F344-to-WKY) the influence of acute rejection (AR) on the development of chronic rejection (CR) was studied.

METHODS

In Group I (n = 25) no immunosuppression was used, while methylprednisolone (MP) (10 mg/kg) was applied in Group II (n = 20) in the early phase of AR on postoperative Days 9, 10, 11 and in Group III (n = 20) during AR on Day 14, Day 15, Day 16. The rats were sacrificed on Day 5, Day 15/20, Day 30, Day 60, Day 100 and following HE-staining the extend of AR as well CR was graded according to the working formulation of The International Society of Heart and Lung Transplantation.

RESULTS

In Group I, AR was found at Day 15 and Day 30 which resolved spontaneously and resulted in CR on Day 60 and Day 100. In Group II, signs of AR were less evident on Day 20, while mild AR persisted on Day 30 and Day 60. On Day 100, normal lung structure was found in all rats. The recipients of Group III showed decreased signs of AR in the early course, however, severe CR was found on Day 60 and Day 100. Extensive airway inflammation with destruction of the subepithelial layer of the smaller airways resulted in severe early obliterative bronchiolitis.

CONCLUSIONS

Untreated severe AR in the early course after lung transplantation results in CR in the F344-to-WKY model. Preventive treatment with MP during the early phase of AR clearly diminishes the degree of AR and the graft recovers completely without any evidence of CR. Late application of steroids during the zenith of AR is successful to control the extent of AR, however, it fails to prevent CR.

Ultrastructural pathology of the alveolar type II pneumocytes of human donor lungs. Electron microscopy, stereology, and microanalysis

Alveolar type II pneumocytes (PII) were studied in 12 human donor lungs perfused with modified Euro-Collins solution during single-lung transplantation (SLTx). While one lung was transplanted, the contralateral donor lung (cDL) was fixed at the time of SLTx for examination by electron microscopy, stereology, and microanalysis. Three groups were then formed: group A (n = 7), cDL without contusions, uneventful early postoperative course; group B (n = 3), cDL with conclusions, uneventful early postoperative course; group C (n = 2), cDL without contusions, early postoperative respiratory dysfunction. The major findings were that the presence of contusions had no effect on PII ultrastructure and that intracellular surfactant-storing lamellar bodies of cDL in group C were characterized by a higher volume-to-surface ratio (VsR) and larger area per cell profile than group A. Correlation analysis based on pooled data (groups A and C) showed that ischaemic time had little effect on PII ultrastructure and bore no relationship to postoperative clinical variables. The duration of preoperative donor intubation had a pronounced influence on ultrastructure and postoperative clinical variables. The stereologically estimated amount of intracellular surfactant and mitochondrial VsR were the only ultrastructural parameters that were significantly associated with early postoperative oxygenation. Lamellar bodies were the only ultrastructural components found to have a significant relationship to postoperative intubation time. The ultrastructural integrity of type II pneumocytes of human donor lungs is an important determinant of early respiratory function following clinical lung transplantation.

Influence of bicaval anastomoses on late occurrence of atrial arrhythmia after heart transplantation

BACKGROUND

The standard technique for orthotopic heart transplantation includes right and left atrial anastomoses, which potentially disturb the integrity of the donor atria. Consequently, electrophysiologic abnormalities such as atrial flutter and fibrillation may occur even late after heart transplanation.

METHODS

Over a 3-year period, 39 heart transplantations were performed using a standard right atrial anastomosis (group A), and 40 were done using bicaval anastomoses (group B). In each group, data of 30 consecutive patients with a minimum follow-up of 9 months were reviewed retrospectively to assess the incidence of atrial arrhythmia after hospital discharge.

RESULTS

Early postoperatively, there was no difference in the duration of temporary pacemaker requirement and incidence of permanent pacemaker implantation (group A, 7%; group B, 7%; not significant) between the two groups. In 12 patients in group A (40%), 16 episodes of atrial flutter and fibrillation were detected 20 to 205 days after heart transplantation. In group B, 1 patient (4%) suffered from atrial fibrillation on day 116 after the operation (p < 0.001).

CONCLUSIONS

Preservation of the integrity of the right donor atrium by construction of bicaval anastomoses results in a significantly decreased incidence of atrial flutter and fibrillation after heart transplantation when compared with the standard technique.

Do long-term results justify bridging to heart transplantation in patients with multi-organ dysfunction?

This retrospective study was performed to determine the influence of multi-organ dysfunction and the type of preoperative hemodynamic support on mortality after heart transplantation. All patients undergoing heart transplantation during a 6 year period were divided into 3 groups: group A patients (n = 110) had stable hemodynamics on oral medication, group B recipients (n = 41) received continuous i.v. catecholamine application, and in group C (n = 21) mechanical hemodynamic support was necessary. In groups B and C elevated serum creatinine and transaminase levels-reflecting renal and hepatic dysfunction-were detected more often and the survival rate was worse during the first six months (A: 85%, B: 71%, C: 52%, p < 0.01). In group C the prognosis of patients with multi-organ dysfunction was significantly worse compared to patients with normal renal and hepatic function (38% vs. 75%; p < 0.01). In recipients surviving for six months, there was no difference in long-term prognosis between the groups studied. It is concluded that heart transplantation in patients with multi-organ dysfunction on invasive hemodynamic support bears a significantly increased risk in the early postoperative period. In view of the current donor shortage the condition of other organs should be improved before transplantation as far as possible, even using long-term mechanical support.

Effects of ischaemia and preservation on the ultrastructure of the bronchiolar epithelium. A quantitative electron microscopic study of human and canine lungs

In ten cases of clinical human single-lung transplantation, the nontransplanted Euro-Collins-preserved contralateral lungs were examined using electron microscopy to determine the effects of ischaemia on the bronchiolar epithelium. Existing structural damage at the time of transplantation was characterized using this approach, and nine nonpreserved canine single lungs were also investigated to identify the impact of ischaemia. The study revealed a significant correlation between the duration of ischaemia and the mitochondrial surface-to-volume ratio, which can serve as a morphometric criterion for mitochondrial damage, in canine lungs. However, this correlation was not found in the human donor lungs. Further examination of human donor lungs showed slight to moderate damage to the endoplasmic reticulum and nuclear chromatin. In addition, various degrees of damage to mitochondrial structure, ranging from inconspicuous to severe, were found. The mitochondrial surface-to-volume ratio can be considered to be a suitable criterion for the quantification of ischaemic damage of the bronchiolar epithelium under experimental conditions. Ultrastructural analysis of human donor lungs revealed intact bronchiolar epithelial cell structures at the time of transplantation, reflecting adequate organ preservation with Euro-Collins solution.

Therapy for lung failure using nitric oxide inhalation and surfactant replacement

Nitric oxide inhalation and surfactant replacement therapy are relatively new concepts in the treatment of respiratory failure due to hypoxia and reperfusion injury after lung transplantation. We report on a patient in whom reperfusion injury of the lung developed after resuscitation and implantation of a biventricular assist device for sudden cardiac arrest. Lung failure developed within 12 hours after implantation of the biventricular assist device. Lung function was reestablished using combined therapy of nitric oxide and surfactant. Heart transplantation was performed successfully thereafter. This case indicates the potential role of a combined therapy of nitric oxide and surfactant in acute hypoxic lung failure.

Thoracoscopic creation of a pericardial window for recurrent pericardial effusion after heart transplantation

A 56-year-old man underwent orthotopic heart transplantation (Htx) for dilative cardiomyopathy. The postoperative course was uneventful despite the appearance of pericardial effusions during the first 6 months, which required repeated drainage therapy. Six months postoperatively a pericardial window was created using a thoracoscopic approach via the right pleural cavity. The course after this intervention was uncomplicated and there was no recurrence of the pericardial effusion during 18 months of follow-up.

Morphometric characterisation of the fine structure of human type II pneumocytes

BACKGROUND

Pulmonary type II pneumocytes have been examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and morphometry in numerous mammals. Until now, the fine structure of the human type II pneumocyte has not been studied by means of morphometry.

METHODS

Eleven human donor lungs, which could not be made available for a suitable recipient, were preserved with Euro Collins solution (ECS) according to clinical organ preservation techniques. The lungs were fixed via the airways. Systematic random samples were analyzed by SEM, TEM, and classical stereological methods.

RESULTS

Type II pneumocytes showed normal fine structural characteristics. Morphometry revealed that although inter-individual variation due to some oedematous swelling was present, the cells were in a normal size range as indicated by an estimated mean volume of 763 +/- 64 microns 3. The volume densities were: nucleus 21.9 +/- 2.2%, mitochondria 5.8 +/- 0.9%, lamellar bodies 9.8 +/- 3.6%, and remaining cytoplasmic components 62.4 +/- 2.9% of the cell volume. Since the inter-individual variations in the volume densities referred to the cell may, to variable degrees, reflect the variation in the reference space, the volume densities referred to the constant test point system and the respective volume-to-surface ratios were used for inter-individual comparisons. These parameters indicate that lamellar bodies were independent of cellular swelling, while mitochondria < nucleus < remaining cytoplasmic components increased in size with increasing cell size.

CONCLUSIONS

Two to 7.5 hours of cold ischemia following ECS preservation do not deteriorate the fine structure of type II pneumocytes of human donor lungs. For reliable assessment of fine structural variations, morphometric parameters are required that are independent of variations in cell size.

Functional results after lung retransplantation

In selected cases with either acute or chronic graft failure after lung or heart-lung transplantation, retransplantation remains the only therapeutic option. Since December 1987, we have performed a total of 110 single lung, bilateral lung, and combined heart-lung transplantations in 102 patients including five early and four late retransplantations in eight patients. Early retransplantation was indicated for severe reperfusion injury after single lung transplantation (n = 2) or heart-lung transplantation (n = 1), for persistent pulmonary hypertension caused by an unrecognized aortopulmonary window (n = 1), for central airway necrosis, and for contralateral pulmonary artery bleeding after bilateral lung transplantation (n = 1). Two of these patients after single lung transplantation were bridged with extracorporeal membrane oxygenation for 9 and 11 days until single lung retransplantation. Three patients underwent late single lung retransplantation 14, 24, and 26 months after single lung transplantation (n = 2) or heart-lung transplantation (n = 1) for chronic rejection, and an additional patient was treated successfully by bilateral lung retransplantation for obliterative bronchiolitis and central airway stenosis 26 months after bilateral lung transplantation. Two patients died 19 and 140 days, respectively, after acute retransplantation because of early graft failure and progressive rejection, respectively, while the other patients were discharged from the hospital. Mortality was 22.2% in the retransplantation group versus 15.1% (11 of 73 patients) undergoing primary single lung transplantation or bilateral lung transplantation (not significant). Patient survival after retransplantation ranged between 159 and 993 days (median, 453 days). Duration of postoperative ventilation was markedly prolonged in patients who underwent retransplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Euro-Collins flush perfusion in human lung preservation--ultrastructural studies of the preservation quality of the contralateral donor lung in clinical single lung transplantation

The quality of pulmonary preservation after Euro-Collins flush perfusion was assessed by means of morphometric analysis based on transmission electron microscopy. In five patients undergoing single lung transplantation, the contralateral donor lung that could not be matched for another recipient was studied by means of light microscopy and transmission electron microscopy. While one of the donor lungs was transplanted, the contralateral lung was fixed by airway instillation at the same time and subsequently processed for microscopic examination. Although light microscopy showed an excellent quality of organ preservation, transmission electron microscopy revealed the presence of fine to medium alterations at the level of the air-blood-barrier. In the five contralateral donor lungs, different degrees of the cellular alterations were recorded by morphometric analysis, which correlated with differences observed in the early postoperative course of the patients receiving the other lung, respectively. Although in four of five patients the clinical course showed no complications and extubation was performed within 36 hours after the operation, one patient required artificial ventilation over a period of 10 days because of impaired oxygenation of the transplanted lung. In this patient, morphometric analysis of the air-blood-barrier showed a significantly (p < 0.02) smaller surface fraction of normal type 1 pneumocytes, a significantly (p < 0.05) smaller volume density of the capillary endothelial cells, and a significantly (p < 0.01) higher volume density of type 2 pneumocytes. The alterations of the alveolar epithelium have to be interpreted as a result of influences occurring during the donor's medical history rather than being an effect of preservation and/or ischemia.

Scanning and transmission electron microscopy of human donor lungs: fine structure of the pulmonary parenchyma following preservation and ischemia

In six cases of clinical single-lung transplantation, the contralateral donor lungs were studied by means of scanning (SEM) and transmission (TEM) electron microscopy. SEM and TEM revealed an overall good to excellent preservation of the pulmonary parenchyma. Since the donor double lung blocks, which were preserved by means of pulmonary arterial perfusion with modified Euro-Collins solution, were separated immediately prior to transplantation, transplanted and contralateral lungs had been subjected to identical influences. Comparing the arterial oxygenation achieved in the recipient 6 h after transplantation with the structural data of the corresponding contralateral donor lung, the degree of epithelial alterations appeared to be most important in determining postoperative lung function. Concerning the assessment of the quality of the alveolar epithelium, gradings performed independently by means of SEM and TEM yielded largely corresponding scores, while a significant shortcoming of SEM was the very limited access to the endothelial surface. Taking into account the relevance of epithelial injury in determining postoperative lung function, SEM can provide clinically relevant data more quickly than TEM. To quantify the fine structural alterations of human donor lungs, however, TEM-based morphometry is required.