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.

Dangerous surgical scavenger hunt: the complicated course of a patient with left ventricular assist device and end-stage renal disease undergoing reconstructive flap surgery.

Patients with left ventricular assist devices (LVADs) who develop stage IV sacral pressure sores (SPS) have an increased procedural risk. We present the complications, including severe intra- and postoperative bleeding, diarrhea with metabolic acidosis, volume loss and acute on chronic renal failure, flap dehiscence and late LVAD outflow cannula thrombosis, in a 54-year-old male who underwent diverting ileostomy (DI) and subsequent fasciocutaneous flap (FCF) surgery for stage IV SPS while supported with an LVAD. Our experience suggests that, despite continuous heparinization, life-threatening thrombotic complications, such as device clotting, can occur. Therefore, the benefit of intervention has to outweigh the risk of bleeding, which should be managed with meticulous surgical technique and substitution of red blood cells rather than the reversal of heparinization or the substitution of clotting factors. Continuation of double anti-platelet therapy should also be considered.

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.

Early administration of FTY720 prevents chronic airway as well as vascular destruction in experimental rat lung transplantation.

BACKGROUND: Chronic rejection (CR) in terms of bronchiolitis obliterans (BO) and vascular sclerosis (VS) still represents the major obstacle for pulmonary graft survival in the medium and long term course after lung transplantation (LTX). Aside from nonspecific stimuli, early acute rejection (AR) seems to be causative especially in cases of a late diagnosis or inadequate treatment. This study investigated the effects of FTY720, a new immunosuppressant that promotes lymphocyte sequestration into lymph nodes and Peyer's patches, on the development of CR after experimental LTX. METHODS: A total of 50 rats underwent allogenic (F344-to-WKY) and syngenic (WKY-to-WKY) left LTX. Group 1 animals had no treatment. Group 2 animals were administered FTY720 (3 mg/kg body weight per day) at the maximum time of AR (day 14) and continued up to day 100 after LTX. Group 3 animals were treated with the same dosage of FTY720 from day 0 to 100. The grades of AR and CR were classified according to the criteria of the International Society for Heart and Lung Transplantation. RESULTS: Within 14 days after allogenic LTX, all nontreated rats developed early AR followed by severe CR with VS and BO. Similar data were observed for FTY720 treatment of existing AR (group 2). Only early administration of FTY720 (at the time of LTX) significantly reduced the proportion of animals with severe acute vascular rejection (P < .001). However, all of these allografts showed high-grade acute airway inflammation. After long-term application, the chronic inflammatory response was absent; none of the allografts developed BO and VS. CONCLUSION: Only application of FTY720 immediately after LTX prevented lymphocyte recirculation and lung injury.

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.

Everolimus versus mycophenolate mofetil in heart transplantation: a randomized, multicenter trial.

In an open-label, 24-month trial, 721 de novo heart transplant recipients were randomized to everolimus 1.5 mg or 3.0 mg with reduced-dose cyclosporine, or mycophenolate mofetil (MMF) 3 g/day with standard-dose cyclosporine (plus corticosteroids ± induction). Primary efficacy endpoint was the 12-month composite incidence of biopsy-proven acute rejection, acute rejection associated with hemodynamic compromise, graft loss/retransplant, death or loss to follow-up. Everolimus 1.5 mg was noninferior to MMF for this endpoint at month 12 (35.1% vs. 33.6%; difference 1.5% [97.5% CI: -7.5%, 10.6%]) and month 24. Mortality to month 3 was higher with everolimus 1.5 mg versus MMF in patients receiving rabbit antithymocyte globulin (rATG) induction, mainly due to infection, but 24-month mortality was similar (everolimus 1.5 mg 10.6% [30/282], MMF 9.2% [25/271]). Everolimus 3.0 mg was terminated prematurely due to higher mortality. The mean (SD) 12-month increase in maximal intimal thickness was 0.03 (0.05) mm with everolimus 1.5 mg versus 0.07 (0.11) mm with MMF (p < 0.001). Everolimus 1.5 mg was inferior to MMF for renal function but comparable in patients achieving predefined reduced cyclosporine trough concentrations. Nonfatal serious adverse events were more frequent with everolimus 1.5 mg versus MMF. Everolimus 1.5 mg with reduced-dose cyclosporine offers similar efficacy to MMF with standard-dose cyclosporine and reduces intimal proliferation at 12 months in de novo heart transplant recipients.

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.

Lung transplantation in the fischer 344-wistar kyoto strain combination is a relevant experimental model to study the development of bronchiolitis obliterans in the rat.

Chronic allograft rejection and bronchiolitis obliterans (BO) limited successful long-term outcome after lung transplantation (LTX). Reliable animal models are needed to study the pathogenesis of BO and to develop effective therapeutic strategies. The relevance of an available experimental LTX model without immunosuppression-the Fischer (F344)-Wistar Kyoto (WKY) rat strain combination-was analyzed. The kinetics of acute and chronic rejection and respective graft histopathology were described in the F344-to-WKY rat strain combination after allogeneic LTX. A modified classification of chronic lung allograft rejection was introduced to describe obliterative changes in the airways after rat LTX. Animals from Harlan Winkelmann (HW) and Charles River (CR) were examined. Within 14 days after LTX, allografts showed moderate to severe acute vascular and bronchiolar inflammation. In contrast to rats from CR, animals from HW showed a delayed acute rejection process. Mid-term phase after LTX (days 20-40) presented a "borderline form" consisting of both acute and first signs of chronic airway rejection. On postoperative day (POD) 60, first signs of airway remodelling and distinct BO were diagnosed in 80% of animals from HW. At the same time, the allografts with BO-like lesions increased up to 100% in rats from CR. The F344-to-WKY rat LTX model allows detailed assessment of all features of acute and chronic pulmonary rejection representing a clinically relevant model. However, due to breeding differences resulting in various sublines of the same rat strain, the source and husbandary history of the animals is important for analysis of immuno-mediated processes.

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.

Clinical research and diagnostic efficacy studies in the oral and maxillofacial radiology literature: 1996-2005.

OBJECTIVES: The aim of this study was to determine the level of evidence that is published in the oral and maxillofacial radiology (OMR) literature. METHODS: OMR papers published in Dentomaxillofacial Radiology and Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology between 1996 and 2005 were classified using epidemiological study design and diagnostic efficacy hierarchies. The country of origin and number of authors were noted. RESULTS: Of the 725 articles, 384 could be classified with the epidemiological study design hierarchy: 155 (40%) case reports/series and 207 (54%) cross-sectional studies. The distribution of study designs was not statistically significant across time (Fisher's exact test, P = 0.06) or regions (P = 0.89). The diagnostic efficacy hierarchy was applicable to 246 articles: 71 (29%) technical efficacy and 166 (67%) diagnostic accuracy studies. The distribution of efficacy levels was not statistically significant across time (P = 0.22) but was significant across regions (P < 0.01). Authors from Japan produced 26% of the papers with a mean ± standard deviation of 5.78 ± 1.98 authors per paper (APP); American authors, 23% (3.78 ± 1.72 APP); and all others, 51% (3.76 ± 1.51 APP). CONCLUSION: The OMR literature consisted mostly of case reports/series, cross-sectional, technical efficacy and diagnostic accuracy studies. Such studies do not provide strong evidence for clinical decision making nor do they address the impact of diagnostic imaging on patient care. More studies at the higher end of the study design and efficacy hierarchies are needed in order to make wise choices regarding clinical decisions and resource allocations.

Impact of the Eurotransplant high-urgency heart allocation system on the outcome of transplant candidates in Germany.

BACKGROUND: In 2000, the Eurotransplant Foundation changed the allocation criteria following the enactment of the German Transplantation Law (GTL). Our study investigated the impact of the new allocation system on outcomes after heart transplantation (HTx) in Germany. METHODS: We compared 2 cohorts of patients who underwent HTx at our institution in two different 3-year periods before (Group 1: 01/1995-12/1997) and after (Group 2: 01/2003-12/2005) implementation of the new system. RESULTS: An increase in the ratio of HTx performed on an urgency basis was found in Group 2 (8.3 % vs. 87.2 %; P < 0.001). The median waiting time and the ischemia time were significantly lower in Group 1 ( P < 0.05). Postoperatively, the length of ICU stay was significantly higher in Group 2 ( P = 0.04). CONCLUSION: The new allocation system decreased the proportion of local and regional organ harvesting. It generates a higher ischemia time without increasing the number of transplantations and without improving the clinical outcome after HTx. The severity of heart failure, rate of secondary organ impairment, and comorbidity is markedly elevated in patients waiting for HTx on HU.

Minimized extracorporeal circulation in coronary artery bypass surgery is equivalent to standard extracorporeal circulation in patients with reduced left ventricular function.

BACKGROUND: Minimized extracorporeal circulation (MECC) is a promising alternative to standard extracorporeal circulation (ECC) and its use is increasing in routine coronary bypass surgery. We analyzed the clinical outcome of patients with reduced left ventricular function who underwent coronary artery bypass surgery with MECC or with standard ECC. METHODS: From January 2003 to September 2008, 238 patients with a left ventricular function < 30 % underwent bypass surgery with ECC or MECC. The primary end point of our retrospective observational study was 30-day mortality. Secondary endpoints were the transfusion requirements, as well as intensive care and the in-hospital course. RESULTS: Demographic data, comorbidities and left ventricular function were similar in the study groups. MECC patients had a tendency towards a lower 30-day mortality rate, a better postoperative renal function and reduced ventilation times. Extracorporeal circulation time and postoperative high-dose inotropic support were significantly lower in the MECC group, while the stays in the intensive care unit and in hospital were comparable between the two groups. In our study, age in the ECC group, and previous infarction and New York Heart Association grade IV in the MECC group were preoperative risk factors associated with a higher mortality. CONCLUSION: Coronary bypass surgery using MECC is feasible and safe for patients with severely impaired left ventricular function. It is a promising alternative to ECC with a low mortality rate and a more favorable postoperative course.

C2 therapeutic drug monitoring of cyclosporine is a safe and feasible method in de novo heart transplant patients.

BACKGROUND: The narrow therapeutic window of cyclosporine (CsA) requires close therapeutic drug monitoring (TDM). While C2-TDM has been established after renal and liver transplantations, clinical experience is limited for patients after de novo heart transplantation (HTX). PATIENTS AND METHODS: In a retrospective study, we investigated 40 patients undergoing HTX; 34 patients received induction therapy using antithymocyte globulin (ATG Mérieux). Immunosuppression was administered with CsA (Sandimmun-Optoral), with dosages adjusted according to C2 levels (800-1100 ng/mL during the first 6 months and reduced to 400-600 ng/mL from the beginning of the first year). At different times TI (months 1-3). TII (months 12-14) TIII (months 24-26), and TIV (months 34-36), we obtained measures of acute cellular rejections (ARs), cytomegalovirus (CMV) infections, creatinine, and safety laboratory parameters. RESULTS: The cumulative survival was 95% after 1 year, and 88% after 3.8 years. Eight ARs were diagnosed at a mean of 7.6 months after HTX in 7 patients. Twenty-four CMV infections/reactivations were verified. In 10 cases, treatment was started because of clinical symptoms. The mean creatinine values significantly rose in the early postoperative phase (TI: 1.23+/-0.47 mg/dL, TII: 1.49+/-0.41 mg/dL; P<.0001). Thereafter the creatinine values declined; however, this was not statistically significant (TIII: 1.38+/-0.57 mg/dL, TIV: 1.15+/-0.30 mg/dL). All other safety parameters showed no significant changes. CONCLUSIONS: C2 allows individualization of immunosuppression with reduced CsA toxicity, but without loss in safety among de novo patients after HTX. We obtained freedom from severe AR, a low number of CMV infections, and excellent patient survival.

[Mutation in factor II and factor V gene in patients with peripheral arterial occlusive disease]. / Chronisch-arterielle Verschlusskrankheit der Beine im Stadium IIb-IV: Molekulargenetische Diagnostik von Mutationen im Faktor-II-und Faktor-V-Gen.

Mutations in factor-V- and factor-II-genes are correlated with an increased risk for venous thrombosis according to the literature. The significance of the mutations in factor- II- and factor-V-genes for the development of the peripheral arterial occlusive disease is not known. Therefore, we investigated the presence of these mutations in 152 patients with documented peripheral arterial occlusive disease and 318 controls without peripheral arterial occlusive disease with polymerase chain reaction (PCR). There was no association between factor-II-mutation and peripheral arterial occlusive disease. The factor-V-mutation, however, was increased in patients with peripheral arterial occlusive disease double fold (12 positive cases in 318 controls, 12 positive cases in 152 patients with peripheral arterial occlusive disease). The significance level was reached (p = 0.05) in statistical analysis but the result did not fall below the significance level as necessary to reach statistical significance (odds ratio 2.19). Nevertheless, from these data we have to discuss a biological relevance of factor-V-mutation in the pathogenesis of peripheral arterial occlusive disease.

Matrix metalloproteinase-9 in bronchiolitis obliterans syndrome after lung transplantation.

Bronchiolitis obliterans syndrome (BOS) is a severe complication after lung transplantation (LTX). In a retrospective cohort study 12 stable healthy recipients (non-BOS) and eight patients with BOS were enrolled after LTX and matrix metalloproteinases (MMP)-9, TIMP-1 and cell characteristics in bronchoalveolar lavage (BAL) samples (n = 145) were analysed. BALs from patients with BOS were further divided according to whether they were obtained before (pre-BOS) or after manifestation of BOS (BOS group). The MMP-9/TIMP-1 ratio was significantly increased in the BOS group compared with non-BOS or pre-BOS; furthermore, the ratio was negatively correlated with forced expiratory volume in one second. In zymography, the active form of MMP-9 was detected predominantly in the BOS group. In addition, zymography showed the banding pattern of neutrophil-derived MMP-9, indicating that polymorphonuclear neutrophils (PMNs) were the main source of MMP-9. According to that, MMP-9 was significantly correlated with the number of PMN. In immunocytochemistry, MMP-9 was also associated predominantly with PMN. This is the first study to evaluate the expression of matrix metalloproteinase-9 and tissue inhibitors of metalloproteinases-1 over time during manifestation of a fibroproliferative lung disease in patients. It demonstrates development of bronchiolitis obliterans syndrome after lung transplantation is associated with an imbalance of matrix metalloproteinases-9/tissue inhibitors of metalloproteinase-1 ratio.

[Extravertebral cement drainage with occlusion of the extradural venous plexus into the vena cava after vertebrobplasty. Case report and review of the literature]. / Extrakorporaler Zementabfluss mit Füllung des extraduralen Venenplexus bis in die V. cava nach Vertebroplastie. Fallbericht und Aufarbeitung des Schrifttums.

This paper presents the case report of an 88 year old female who came to hospital suffering from a severe lower back pain. Ten days before, she had undergone a vertebroplasty with injection of cement into lumbar vertebra 3 because of an osteoporotic fracture. This treatment did not result in a reduction of the lower back pain, which was the main reason for the procedure. However, the patient claimed to have increasing pain radiating to her left leg. Furthermore, she suffered from numbness of her left leg. Clinical examination showed a lack of power in this leg according to hip flexion with a degree of 3/5. X-ray examinations showed paravertebral cement particles and led to the suspicion that the paravertebral cement had caused nerve root compression. MRI and CT myelography showed that the cement had drained into the intraspinal, extradural venous plexus (Batson's plexus). The plexus was filled out with cement between L2 and L5 on both sides. There was nearly no cement in the fractured vertebra L3, but cement had also run onto the paravertebral veins up to the vena cava, which was also involved. The cemented veins had led to a stenosis of the neuroforamina L2 and L3 on the left side. The result was compression of left L3 nerve root. After consulting with our vascular surgeons, we decided on a non-operative treatment. We prescribed a lumbar brace as external stabilisation and as an antithrombotic treatment we gave the patient weight adapted low molecular weight heparin.

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.