Non-HLA antibodies targeting vascular receptors enhance alloimmune response and microvasculopathy after heart transplantation.

BACKGROUND: Non-human leukocyte antigen antibodies (Abs) targeting vascular receptors are implicated in the pathogenesis of renal allograft vascular rejection and in progressive vasculopathy in patients with systemic sclerosis. METHODS: We prospectively tested in 30 heart transplant recipients the impact of Abs directed against endothelin-1 type A (ET(A)R) and angiotensin II type 1 receptors (AT(1)R, cell-enzyme-linked immunosorbent assay) at time of transplantation and during the first posttransplantation year on cellular and Ab-mediated rejection (immunohistochemistry, C3d, and immunoglobulins) and microvasculopathy in endomyocardial biopsy. RESULTS: Cellular rejection, Ab-mediated rejection, and microvasculopathy was found in 40% and 13%, 57% and 18%, and 37% and 40% of biopsies at 1 month and 1 year posttransplantation, respectively. Maximum levels of AT(1)R and ET(A)R Abs were higher in patients with cellular (16.5±2.6 vs. 9.4±1.3; P=0.021 and 16.5±2.5 vs. 9.9±1.9; P=0.041) and Ab-mediated rejection (19.0±2.6 vs. 10.0±1.3; P=0.004 and 19.4±2.7 vs. 9.0±1.7; P=0.002), as compared with patients who had no rejection. Patients with elevated AT(1)R Abs (53% [16/30]) or ETAR Abs (50% [15/30]; pretransplantation prognostic rejection cutoff >16.5 U/L) presented more often with microvasculopathy (both, 67% vs. 23%; P=0.048) than patients without. CONCLUSIONS: Elevated levels of AT(1)R and ET(A)R Abs are associated with cellular and Ab-mediated rejection and early onset of microvasculopathy and should be routinely monitored after heart transplantation.

Clinical, haemodynamic and echocardiographic features of early cardiac graft dysfunction.

BACKGROUND: The main cause of early death after heart transplantation (HTx) is so-called early primary or secondary graft failure (GF). The risk of profound GF has not declined in the past decade, as the consequence of the liberalisation of donor acceptance criteria because of the scarcity of donors. It is therefore important to try to diagnose graft failure and recognise the mechanisms of early graft dysfunction. AIM: To establish haemodynamic and echocardiographic criteria of early GF to define patients who should be considered for assist device support or re-transplantation. METHODS: Between January 2000 and March 2009, 116 HTx patients were studied. On the basis of echocardiography and continuous invasive monitoring, three groups were identified: (1) The true graft failure group (GF) consisted of 46 patients; (2) The latent right ventricular (RV) dysfunction group (RV-D) consisted of 25 patients with small left ventricular (LV) chamber (〈 39 mm) and RV ejection fraction (RVEF) 〈 50%; (3) The control group consisted of 45 consecutive HTx patients without any haemodynamic complications. RESULTS: Postoperatively, only the GF group required large doses of norepinephrine (〉 0.3 µmg/kg/min) and inhalative NO (40 ppm). Nevertheless, right and left filling pressures were significantly higher than in the controls (right 12 ± 3.6 vs. 9.0 ± 2 and left atrial pressure 13.0 ± 3.2 vs. 9.6 ± 2 mm Hg, both p 〈 0.001). Cardiac index was significantly smaller (2.9 ± 0.7 vs. 3.7 ± 0.9, p 〈 0.001) but neither pulmonary artery pressure (29.5 ± 6 vs. 29.7 ± 7 mm Hg) nor transpulmonary gradient (6 ± 5 vs. 5.1 ± 5 mm Hg) nor pulmonary vascular resistance (273 ± 97 vs. 287 ± 144 dyn × s × cm-5) differed significantly from those of the control group. In the GF group, LV end diastolic dimension (LVEDD) was significantly smaller and function poorer than in controls (39.8 ± 5 vs. 44.4 ± 5 mm, respectively, p = 0.001). RV function was also significantly worse (RVEF 42.2 ± 14% vs. 56.0 ± 9%), respectively, p = 0.001), whereas RV dimension did not differ significantly. Mechanical support after failure of the initial medical treatment was necessary in 37% of patients; 29 (63.0%) patients from the GF group died, the cause of death being sepsis with multi-organ failure. In the RV-D group, remodelling was quite similar but LVEF was excellent and maximal systolic velocity from the posterior wall was significantly higher than in GF. No death occurred. CONCLUSIONS: True early GF represents a grave haemodynamic situation with high mortality. Bedside echocardiography helps to distinguish between latent RV dysfunction and true GF.

Invasive pressure monitoring saves from tuberculous meningitis with fulminant generalized brain edema.

We report a 57-year old female patient with a rapid and dramatic dynamic of whole brain edema caused by tuberculous meningitis. After initiation of tuberculostatic medication, general condition of the patient worsened and finally she was intubated due to a progredient loss of consciousness and respiratory insufficiency. Repeated cerebral computer tomography (CCT) revealed a global brain edema with slit ventricles and a dramatic progress of generalized brain swelling. Highly interesting, a rapid expanded regime of brain pressure monitoring and treatment according to a neurosurgical intensive standard ICP/CPP management protocol, which was complemented by the tuberculostatic therapy and high dose steroid application, dramatically improved the general conditions, so that the patient is now in a general condition which corresponds that before the occurrence of tuberculous meningitis. Thus, it is mandatory in situations with a rapid progressive brain swelling caused by bacterial meningitis to consider an intensified cerebral monitoring and stratified treatment protocol in order to avoid the devasting effects of a long lasting increase in intracranical pressure.

Everolimus prevents endomyocardial remodeling after heart transplantation.

BACKGROUND: Endomyocardial remodeling is characterized by progressive fibrosis and scars and may develop after heart transplantation. The role of everolimus in preventing this process has not been evaluated as yet. METHODS: We prospectively studied 132 patients at baseline pretransplant and at 4 weeks, 1 year, and 3 years after heart transplantation. Fibrosis, scars (Zeiss Vision, in Sirius), and acute cellular rejection (hematoxylin-eosin) were studied in biopsy. Transplant vasculopathy was assessed by coronary angiography (focal stenoses, peripheral obliterations, negative vascular remodeling defined by peripheral obliterations, and diffusely narrowed proximal and mid vessel segments). RESULTS: Patients on everolimus versus patients on mycophenolate mofetil presented with significantly less fibrosis at 4 weeks (3.8%±0.3% vs. 5.5%±0.3%, P=0.007), 1 year (4.1%±0.3% vs. 4.8%±0.3%, P=0.015), and 3 years (4.2%±0.3% vs. 5.5%±0.7%, P=0.049) posttransplant and showed less scarring at 3 years posttransplant (19.9±1.9% vs. 31.9±4.6% vs. baseline biopsy 26.0±2.8%; P=0.017). Angiographic peripheral obliterations correlated with higher amounts of endomyocardial fibrosis. The negative correlation of everolimus and the positive correlation of peripheral obliterations with fibrosis were confirmed by regression analysis. Angiographic stenoses or acute cellular rejection had no effect on the development of fibrosis. Negative vascular remodeling in 1-year follow-up tended to be less frequent in everolimus-treated patients (24% vs. 76%; P=0.053). CONCLUSIONS: Everolimus prevents endomyocardial remodeling after heart transplantation and might have beneficial effects on vascular remodeling of epicardial coronary arteries too. Angiographic peripheral obliterations correlate with increased amounts of endomyocardial fibrosis, suggesting a relevant effect on microvascular perfusion.

Report from a consensus conference on antibody-mediated rejection in heart transplantation.

BACKGROUND: The problem of AMR remains unsolved because standardized schemes for diagnosis and treatment remains contentious. Therefore, a consensus conference was organized to discuss the current status of antibody-mediated rejection (AMR) in heart transplantation. METHODS: The conference included 83 participants (transplant cardiologists, surgeons, immunologists and pathologists) representing 67 heart transplant centers from North America, Europe, and Asia who all participated in smaller break-out sessions to discuss the various topics of AMR and attempt to achieve consensus. RESULTS: A tentative pathology diagnosis of AMR was established, however, the pathologist felt that further discussion was needed prior to a formal recommendation for AMR diagnosis. One of the most important outcomes of this conference was that a clinical definition for AMR (cardiac dysfunction and/or circulating donor-specific antibody) was no longer believed to be required due to recent publications demonstrating that asymptomatic (no cardiac dysfunction) biopsy-proven AMR is associated with subsequent greater mortality and greater development of cardiac allograft vasculopathy. It was also noted that donor-specific antibody is not always detected during AMR episodes as the antibody may be adhered to the donor heart. Finally, recommendations were made for the timing for specific staining of endomyocardial biopsy specimens and the frequency by which circulating antibodies should be assessed. Recommendations for management and future clinical trials were also provided. CONCLUSIONS: The AMR Consensus Conference brought together clinicians, pathologists and immunologists to further the understanding of AMR. Progress was made toward a pathology AMR grading scale and consensus was accomplished regarding several clinical issues.

International Society for Heart and Lung Transplantation working formulation of a standardized nomenclature for cardiac allograft vasculopathy-2010.

The development of cardiac allograft vasculopathy remains the Achilles heel of cardiac transplantation. Unfortunately, the definitions of cardiac allograft vasculopathy are diverse, and there are no uniform international standards for the nomenclature of this entity. This consensus document, commissioned by the International Society of Heart and Lung Transplantation Board, is based on best evidence and clinical consensus derived from critical analysis of available information pertaining to angiography, intravascular ultrasound imaging, microvascular function, cardiac allograft histology, circulating immune markers, non-invasive imaging tests, and gene-based and protein-based biomarkers. This document represents a working formulation for an international nomenclature of cardiac allograft vasculopathy, similar to the development of the system for adjudication of cardiac allograft rejection by histology.

Angiographic assessment of cardiac allograft vasculopathy: results of a Consensus Conference of the Task Force for Thoracic Organ Transplantation of the German Cardiac Society.

Angiograms of cardiac transplant (HTx) recipients were to be evaluated in a ring experiment and a joint consensus on criteria of angiographic evaluation of coronary arteries of HTx patients was to be reached. Twenty-four coronary angiograms from 11 hospitals were circulated. One hundred eighty-eight blinded evaluations were returned. A joint evaluation by six experienced cardiologists was used as reference standard and a consensus evaluation form was developed. Significant lesions (stenosis 75%, 50% in the left main coronary artery) were diagnosed in 10/23 abnormal coronary angiograms (41.7%). Interventional revascularization was recommended in 8/10 (80%). In 21 coronary angiograms distal pruning was found and in 11/21 (52.4%) cases with distal pruning occlusion of at least one peripheral vessel was detected. The best kappa value (0.7) was found for the presence of at least one clinically significant stenosis. Agreement on the site and grade of local stenosis was much less. Some agreement on remodeling was found in assessing diffuse narrowing in the LCA (kappa=0.371, P<0.001). The kappa value for peripheral obliteration was 0.331 (P=0.001). Angiographic evaluation of cardiac allograft vasculopathy, particularly of diffuse and peripheral disease and remodeling, needs standardization. This should be performed in a downward compatible improvement process.

Heart transplantation at the Deutsches Herzzentrum Berlin.

The Deutsches Herzzentrum Berlin is one of the largest transplant centers in Germany with more than 1700 transplant procedures, more than 170 being procedures in children, in patients from the beginning of life to 71 years of age. Survival rates during the early and intermediate follow-up are lower than in international data; however, long-term survival at 15 years or more is similar. Discrepant survival rates derive mainly from the organ shortage that resulted in the development of a different allocation system in Germany as compared to North America and in the increasing number of patients undergoing the bridge-to-transplant concept to move the patient to transplantability. Thus, the patient at highest risk of death while on the waiting list, who according to the ISHLT registry is also the patient at highest risk of death early post-transplant, is the candidate most likely to undergo transplantation in Germany. Unfortunately, the myth persists of solving the donor organ shortage by increasing the "fairness" of organ allocation. Major goals of our transplant program are: the introduction of non-invasive cellular rejection screening with the intramyocardial electrogram (IMEG) and echocardiography; to characterize microvasculopathy in biopsy as a novel and easily diagnosed marker for poor prognosis; to identify Quilty as a determinant for poor prognosis; to propose classifications for microvasculopathy and epicardial vasculopathy that consider the diffuse character of the disease; and to provide insights into the therapeutic options and potential clinical benefits of novel immunosuppressive strategies.

Reduction of arteriosclerotic nanoplaque formation and size by n-3 fatty acids in patients after valvular defect operation.

BACKGROUND/METHODS: Coating a silica surface with the isolated lipoprotein receptor heparan sulfate proteoglycan (HS-PG) from arterial endothelium and vascular matrices, we could observe the very earliest stages of arteriosclerotic plaque development by ellipsometric techniques in vitro (patent EP 0 946 876). This so-called nanoplaque formation is represented by the ternary aggregational complex of the HS-PG receptor, lipoprotein particles and calcium ions. The model was validated in several clinical studies on statins in cardiovascular high-risk patients applying their native blood lipoprotein fractions. RESULTS: In 7 patients who had undergone a valvular defect operation, the reduction of arteriosclerotic nanoplaque formation in normal Krebs solution amounted to 6.1 +/- 2.3% (p < 0.0156) and of nanoplaque size to 37.5 +/- 13.2% (p < 0.0312), respectively, after a 3-month therapy with n-3 fatty acids (3 ..3 g daily, Ameu 500 mg). Additionally, the quotient oxLDL/LDL was lowered by 6.8 +/- 2.1% (p < 0.0166), the MDA concentration remained unchanged and the lipoprotein(a) concentration decreased by 15.8 +/- 5.6% (p < 0.0469) in the patients' blood. The concentration of the nanoplaque promoting particles VLDL and total triglycerides was diminished by 34.1 +/- 11.6% (p < 0.0469) and 26.7 +/- 10.8% (p < 0.0156), respectively. Furthermore, the ratio of the strongly atherogenic small dense to the total LDL cholesterol (LDL5+LDL6)/LDLtot decreased by 9.9 +/- 3.0% (p < 0.0174). CONCLUSIONS: A combinatorial regression analysis revealed a basis for a mechanistic explanation of nanoplaque reduction under n-3 fatty acid treatment. This effect was possibly due to the beneficial changes in lipid concentrations and an attenuation of the risk factors oxLDL/LDL and (LDL5+LDL6)/LDLtot.

Bronchogenic cyst of the interatrial septum presenting as atrioventricular block.

Bronchogenic cysts are congenital lesions that are a remnant from abnormal budding of the embryonic foregut. These cysts are usually single; most cases are either asymptomatic or present with respiratory symptoms. A 43-year-old woman presented with intermittent type II atrioventricular block during cholecystectomy. The cardiac evaluation including transthoracic and transesophageal echocardiography and magnetic resonance imaging revealed a cystic homogeneous mass within the interatrial septum. The patient underwent surgical resection of the mass and closure of the septal defect. Histopathology identified ciliated columnar epithelium, consistent with the diagnosis of a bronchogenic cyst.

Attenuation of transplant arteriosclerosis with clopidogrel is associated with a reduction of infiltrating dendritic cells and macrophages in murine aortic allografts.

BACKGROUND: Monotherapy with clopidogrel reduced the formation of transplant arteriosclerosis in a murine aortic allograft model. However, the underlying immunologic mechanisms are still unknown. METHODS: Fully major histocompatibility complex-mismatched C57BL/6 (H2b) donor aortas were transplanted into CBA.J (H2k) recipients and mice received different doses (1, 10, and 20 mg/kg) of clopidogrel, an antagonist of the P2Y12 ADP receptor on platelets, or control saline for 30 days. Blood was analyzed for changes in adhesion molecule and sCD40L concentrations by ELISA. Grafts were analyzed by histology, morphometry, and immunofluorescence on day 30 after transplantation. Intragraft cytokine mRNA production was analyzed by reverse-transcriptase polymerase chain reaction on day 14 after transplantation. RESULTS: Treatment with clopidogrel resulted in significantly decreased blood concentrations of sCD40L and P-selectin after transplantation. Cellular analysis of the aortic transplant revealed fewer numbers of infiltrating dendritic cells (CD205+) and macrophages (F4/80+) after application of clopidogrel, whereas T-cells within the graft were unaltered. In addition cellular P-/E-selectin, ICAM-1, and platelet-derived-growth-factor (PDGF)-beta surface expression were significantly reduced as compared with untreated controls. Intragraft mRNA expression confirmed these results and showed significant lower production of P-/E-selectin, ICAM-1, and PDGF-beta after treatment with clopidogrel. Antiglycoprotein-Ib and antiglycoprotein VI had no beneficial effect on the development of transplant arteriosclerosis. CONCLUSION: This report shows that application of clopidogrel after transplantation results in a reduction in adhesion molecule expression within the blood and transplant tissue and is associated with reduced transendothelial migration of dendritic cells and macrophages within the vascular wall.

Beneficial effect of female gender on long-term survival after heart transplantation.

BACKGROUND: We aimed to test whether stenotic microvasculopathy affects the more beneficial course in female cardiac transplant recipients. METHODS: We studied 873 patients (35/151 premenopausal women aged < or =40 years) who underwent primary heart transplantation. In 7750 biopsies harvested within the first posttransplant year endothelial disease and stenotic microvasculopathy were evaluated by light microscopy (Hematoxylin and Eosin). Kaplan-Meier and Cox regression analyses were performed for major cardiac events (MACE; lethal myocardial infarction, sudden cardiac death, graft failure, and cardiac retransplantation). RESULTS: Stenotic microvasculopathy was found equally in men (38%) and women (39%). Allografts from premenopausal female-to-male transplants more frequently developed endothelial disease (78% vs. 65%; P=0.021) and stenotic microvasculopathy (46% vs. 28%, P=0.024). Beyond the first 5 posttransplant years women presented MACE less often than men, independently of donor gender and stenotic microvasculopathy (P=0.0001). Multivariate regression analysis found women to be at lower risk for MACE (Relative Risk [RR] 0.38; 95% Confidence Interval [CI] 0.17-0.81), whereas stenotic microvasculopathy (RR 2.15; 95% CI 1.42-3.26) and treated diabetes (RR 1.65; 95% CI 1.08-2.52) indicated a higher risk for MACE. CONCLUSIONS: Stenotic microvasculopathy has prognostic impact on survival of male and female cardiac recipients; however, it does not affect the more beneficial course of women in the long-term follow-up.

Quilty in biopsy is associated with poor prognosis after heart transplantation.

We tested if Quilty (endocardial infiltration of lymphocytes) in routinely processed endomyocardial biopsy is associated with poor outcome after heart transplantation (HTx). Biopsies (n=9829) harvested within the first post-transplant year from 938 patients (778 men, mean age 49 years) were evaluated for Quilty and acute cellular rejection (according to the International Society for Heart and Lung Transplantation, ISHLT, classification). Transplant vasculopathy was evaluated by coronary angiography, and severe stenosis was found in 19% of patients. Survival was tested by Kaplan-Meier and Cox regression analyses for all-cause mortality and major cardiac events (lethal acute cellular rejection, graft loss or myocardial infarction). We found 1840 (19%) Quilty-positive biopsies in 487 Quilty-positive patients (52%). Quilty was more prevalent in women (p=0.038) and younger men (p=0.001), and was correlated with ISHLT grade 1R (OR 1.45, 95% CI 1.36-1.55; p<0.001) and ISHLT grade 2R (OR 2.48, 95% CI 2.21-3.41; p<0.001). Quilty in any biopsy was associated with a higher all-cause mortality (log rank p=0.045) due to a higher risk for major cardiac event (p=0.0001). Multivariate regression analysis showed Quilty (RR 1.69, 95%CI 1.05-2.73) and transplant vasculopathy (RR 2.78, 95%CI 1.68-4.61) as risk factors for major cardiac events and treated hyperlipidemia as lowering the risk for major cardiac events (RR 0.47, 95%CI 0.28-0.77). Quilty is associated with graft loss and poor outcome post HTx. Index biopsy during the first post-transplant year is a useful tool to identify patients at risk and is recommended during routine post-transplant management.

Coronary flow reserve measurement detects transplant coronary artery disease in pediatric heart transplant patients.

BACKGROUND: Cardiac allograft vasculopathy (CAV) in patients who have undergone heart transplantation leads to graft dysfunction and is still the major concern for long-term survival. Evaluation of coronary flow velocity reserve (CFR) has been established for diagnosis of CAV. Systemic application of adenosine vs intracoronary testing for CFR has been validated in adults; however, its accuracy in pediatric patients has not yet been proven. METHODS: CFR was prospectively measured in 33 clinically asymptomatic pediatric heart transplant recipients. CFR measurements were made in the left anterior descending (LAD) artery using a 0.014-inch Doppler FloWire (Cardiometrics). CFR was defined as the ratio of hyperemic (after adenosine injection) to basal (before adenosine) average peak velocity (APV). Adenosine (Adrekar) was administered by intracoronary (15 or 30 mug bolus) and systemic (0.1 mg/kg) injection in each patient. Epicardial CAV was evaluated in coronary angiograms (Stanford criteria) and microvasculopathy was diagnosed in endomyocardial biopsies (evidence of luminal stenosis) blinded to clinical data. RESULTS: Thirty-three patients were included in this study. Their median age (range) was 11.9 (1.4 to 17) years and median post-transplant time 4.3 (1 to 11.7) years. Seventeen of the 33 patients had epicardial CAV (mainly peripheral obliterations or B1 and B2 lesions) and microvascular CAV. Epicardial CAV only was found in 4 patients and microvasculopathy only was present in only 1 patient. CFR was significantly reduced in patients with epicardial CAV and microvasculopathy when compared with patients without any signs of CAV: 206 +/- 53 vs 276 +/- 39 (p < 0.001) for the systemic application and 213 +/- 50 vs 271 +/- 45 (p = 0.004) for the intracoronary application. CONCLUSIONS: CFR and coronary vasoreactivity to adenosine are decreased in pediatric patients with CAV and correlate with histopathologic and angiographic evidence of microvascular disease. Measurement of CFR with intracoronary and systemic application of adenosine is comparable, while systemic application is necessary for non-invasive measurement of CFR in pediatric patients.

Quilty indicates increased risk for microvasculopathy and poor survival after heart transplantation.

BACKGROUND: The impact of Quilty (sub-endocardial infiltration of lymphocytes) on the development of stenotic microvasculopathy and outcome after heart transplantation has not yet been evaluated. METHODS: Biopsies (n = 9,713) obtained within the first post-transplant year from 873 patients (722 men, age 49.3 +/- 0.3 years) were evaluated by light microscopy (hematoxylin-eosin) for Quilty and cellular rejection (ISHLT), stenotic microvasculopathy (luminal radius:medial thickness ratio <1) and endothelial disease (core diameter:cell diameter ratio < or =1). Risk factors for stenotic microvasculopathy were analyzed by logistic regression. Overall survival and freedom from graft failure (cardiac re-transplantation, myocardial infarction and sudden cardiac death) were estimated by the Kaplan-Meier method and tested using a Cox proportional hazard model. RESULTS: We found 1,830 (19%) Quilty-positive biopsies in 481 (55%) Quilty-formers and stenotic microvasculopathy in 866 (9%) biopsies of 379 (43%) patients. Evidence of Quilty (odds ratio [OR] 1.77; 95% confidence interval [CI] 1.26 to 2.57) and endothelial disease (OR 4.98; 95% 95% CI 3.31 to 7.49) indicated higher risk, whereas post-transplant statin therapy was associated with lower risk for stenotic microvasculopathy (OR 0.68; 95% CI 0.48 to 0.97). Freedom from graft failure was lower in Quilty-formers (p = 0.0060) and even worse if patients suffered from both Quilty and stenotic microvasculopathy (p = 0.0017). Both factors were confirmed in multivariate regression analysis (stenotic microvasculopathy risk ratio [RR] 1.90, 95% CI 1.23 to 2.95; Quilty RR 1.77, 95% CI 1.11 to 2.82, p = 0.0430). CONCLUSIONS: Presence of Quilty indicates increased risk for stenotic microvasculopathy in biopsy early after heart transplantation. Both are associated with poor outcome due to graft failure.