IL-17A influences essential functions of the monocyte/macrophage lineage and is involved in advanced murine and human atherosclerosis.

Atherosclerosis is a chronic inflammatory disease. Lesion progression is primarily mediated by cells of the monocyte/macrophage lineage. IL-17A is a proinflammatory cytokine, which modulates immune cell trafficking and is involved inflammation in (auto)immune and infectious diseases. But the role of IL-17A still remains controversial. In the current study, we investigated effects of IL-17A on advanced murine and human atherosclerosis, the common disease phenotype in clinical care. The 26-wk-old apolipoprotein E-deficient mice were fed a standard chow diet and treated either with IL-17A mAb (n = 15) or irrelevant Ig (n = 10) for 16 wk. Furthermore, essential mechanisms of IL-17A in atherogenesis were studied in vitro. Inhibition of IL-17A markedly prevented atherosclerotic lesion progression (p = 0.001) by reducing inflammatory burden and cellular infiltration (p = 0.01) and improved lesion stability (p = 0.01). In vitro experiments showed that IL-17A plays a role in chemoattractance, monocyte adhesion, and sensitization of APCs toward pathogen-derived TLR4 ligands. Also, IL-17A induced a unique transcriptome pattern in monocyte-derived macrophages distinct from known macrophage types. Stimulation of human carotid plaque tissue ex vivo with IL-17A induced a proinflammatory milieu and upregulation of molecules expressed by the IL-17A-induced macrophage subtype. In this study, we show that functional blockade of IL-17A prevents atherosclerotic lesion progression and induces plaque stabilization in advanced lesions in apolipoprotein E-deficient mice. The underlying mechanisms involve reduced inflammation and distinct effects of IL-17A on monocyte/macrophage lineage. In addition, translational experiments underline the relevance for the human system.

High-sensitive Troponin T measurements early after heart transplantation predict short- and long-term survival.

Following heart transplantation, cardiac biomarkers remain elevated for several weeks eventually as a result of membrane leakage of the donor organ. We now test the predictive power of blood levels of troponin T (TNT) measured by the new hsTNT assay (Roche Diagnostics, Roche Diagnostics, Mannheim, Germany) early after heart transplantation. TNT was determined in 141 cardiac allograft recipients and 40 controls. Our findings demonstrate that patients who died within the first year after transplantation had significantly higher median hsTNT serum levels 6 weeks after transplantation (156 ng/l ± 203 vs. 29 ng/l ± 21, P = 0.0002). Using ROC analysis, a serum hsTNT concentration of 33.55 ng/l 6 weeks after transplantation was found to be the best cutoff to predict death at 1 year (HR 0.16, 95%CI:0.05-0.46, P = 0.001) with a sensitivity of 90.91% and a specificity of 70.97%. In addition, survival at 5 years (HR 0.15, 95% CI 0.06-0.35, P < 0.0001) was significantly better among patients below that cutoff value. In multivariate analysis, hsTNT serum level 6 weeks after transplantation emerged as an independent predictor for first-year mortality (hsTNT-HR 0.90, 95% CI: 0.81-1.00, P = 0.03). Cardiac troponin T concentrations early after transplantation as measured with a highly sensitive assay represent a strong and independent risk predictor of death after heart transplantation.

Assessment of disease severity and outcome in patients with systemic light-chain amyloidosis by the high-sensitivity troponin T assay.

Cardiac biomarkers provide prognostic information in light-chain amyloidosis (AL). Thus, a novel high-sensitivity cardiac troponin T (hs-TnT) assay may improve risk stratification. hs-TnT was assessed in 163 patients. Blood levels were higher with cardiac than renal or other organ involvement and were related to the severity of cardiac involvement. Increased sensitivity was not associated with survival benefit. Forty-seven patients died during follow-up (22.3 ± 1.0 months). Nonsurvivors had higher hs-TnT than survivors. Outcome was worse if hs-TnT more than or equal to 50 ng/L and best less than 3 ng/L. Survival of patients with hs-TnT 3 to 14 ng/L did not differ from patients with moderately increased hs-TnT (14-50 ng/L), but was worse if interventricular septum was more than or equal to 15 mm. Discrimination according to the Mayo staging system was only achieved by the use of the hs-TnT assay, but not by the fourth-generation troponin T assay. Multivariate analysis revealed hs-TnT, NT-proBNP, and left ventricular impairment as independent risk factors for survival. hs-TnT and NT-proBNP predicted survival, even after exclusion of patients with impaired renal function. Plasma levels of the hs-TnT assay are associated with the clinical, morphologic, and functional severity of cardiac AL amyloidosis and could provide useful information for clinicians on cardiac involvement and outcome.

Expression of IL-17A in human atherosclerotic lesions is associated with increased inflammation and plaque vulnerability.

A chronic (auto)immune response is the critical mechanism in atherosclerosis. Interleukin-17A is a pivotal effector cytokine, which modulates immune cell trafficking and initiates inflammation in (auto)immune and infectious diseases. However, expression of IL-17A in the context of human atherosclerosis has hardly been explored. Carotid artery plaques were collected from 79 patients undergoing endarterectomy. Patients were grouped according to their symptomatic status (TIA, stroke), plaque morphology and medication. Quantitative RT-PCR was used to analyze tissue inflammation and immunohistochemistry to assess cellular source of IL-17A expression and lesion morphology. Carotid plaques from patients with ischemic symptoms were characterized by a highly activated inflammatory milieu including accumulation of T cells (p = 0.04) and expression of IL-6 and VCAM1 (p = 0.02, 0.01). Expression of IL-17A and its positive regulators IL-21 and IL-23 was present in atherosclerotic lesions, significantly upregulated in atheromas of symptomatic patients (p = 0.005, 0.004, 0.03), and expression of IL-17A and IL-21 showed a strong correlation (p = 0.002, r = 0.52). The cellular sources of lesional IL-17A expression are T cells, macrophages, B cells and plasma cells. Vulnerable/ruptured (complicated) plaques were significantly associated with IL-17A expression levels (p = 0.003). In addition, IL-17A showed a marked negative correlation with the potent anti-inflammatory/atheroprotective cytokine IL-10 (p = 0.0006, r = -0.46). Furthermore, treatment with a HMG-CoA reductase inhibitor or acetylsalicylic acid showed reduced levels of IL-21, IL-23 and VCAM1 (all p < 0.05), but did not influence IL-17A. The association of IL-17A with ischemic symptoms and vulnerable plaque characteristics suggests that the pro-inflammatory cytokine IL-17A may contribute to atherosclerosis und plaque instability.

Inhibition of IL-17A attenuates atherosclerotic lesion development in apoE-deficient mice.

The importance of an (auto)immune response in atherogenesis is becoming increasingly well understood. IL-17A-expressing T cells modulate immune cell trafficking, initiating inflammation and cytokine production in (auto)immune diseases. In human carotid artery plaques, we previously showed the presence of IL-17A-producing T cells and IL-23; however, IL-17A effects on atherogenesis have not been studied. Aortic root sections from 8-wk-old apolipoprotein E-deficient mice fed a standard chow diet were examined after 12 wk for lesion area, plaque composition, cellular infiltration, cytokine expression, and apoptosis. The treatment group (n = 15) received anti-IL-17A Ab and the controls (n = 10) received irrelevant Abs. Inhibition of IL-17A markedly reduced atherosclerotic lesion area (p < 0.001), maximal stenosis (p < 0.001), and vulnerability of the lesion. IL-17A mAb-treated mice showed reduced cellular infiltration, down-regulation of activation markers on endothelium and immune cells (e.g., VCAM-1), and reduced cytokine/chemokine secretion (e.g., IL6, TNFalpha, CCL5). To investigate possible mechanisms, different atherogenic cell types (e.g., macrophages, dendritic cells, HUVECs, vascular smooth muscle cells) were stimulated with IL-17A in addition to TNF-alpha, IFN-gamma, or LPS to induce cellular activation or apoptosis in vitro. Stimulation with IL-17A induced proinflammatory changes in several atherogenic cell types and apoptotic cell death in murine cells. Functional blockade of IL-17A reduces atherosclerotic lesion development and decreases plaque vulnerability, cellular infiltration, and tissue activation in apolipoprotein E-deficient mice. The present data support a pathogenic role of IL-17A in the development of atherosclerosis by way of its widespread proinflammatory and proapoptotic effects on atherogenic cells.

Quantitative myocardial blush grade for the detection of cardiac allograft vasculopathy.

BACKGROUND: Cardiac allograft vasculopathy (CAV) progressively compromises microvascular perfusion and function in heart transplantation (HTx)-recipients. The aim of our study was to investigate the ability of quantitative myocardial blush grade (MBG) to detect CAV. METHODS: In consecutive HTx-recipients (n = 72) who underwent surveillance cardiac catheterization, MBG was assessed visually and quantitatively, by analyzing the time course of contrast agent intensity rise. Hereby, the parameter G(max)/T(max) was calculated as the plateau of grey-level intensity (G(max)) divided by the time-to-peak intensity (T(max)). HTx-recipients and 18 healthy volunteers underwent cardiac magnetic resonance, to assess diastolic strain rates and myocardial perfusion reserve during pharmacologic hyperemia. RESULTS: Significant correlations were observed between G(max)/T(max) with perfusion reserve and with mean diastolic strain rates (r(2) = 0.68 and r(2) = 0.58, P < .001 for both). Visual and quantitative MBG using a cutoff value of G(max)/T(max) = 2.7/s yielded significantly higher accuracy than stenosis severity on coronary angiograms for the detection of impaired microvascular integrity as a surrogate marker for CAV (AUC = 0.78, SE = 0.06, 95% CI = 0.66-0.87 for lumen narrowing versus AUC = 0.91, SE = 0.03, 95%CI = 0.84-0.97 for G(max)/T(max); P < .01). Furthermore, quantitative MBG provided more robust prediction of survival (chi(2)= 14.0, P < .001), compared to visually estimated blush (chi(2)= 5.4, P = .02) and to coronary lumen narrowing assessment, (chi(2)= 4.8, P = .04). CONCLUSIONS: Quantification of MBG can be performed on coronary angiograms of HTx-recipients, and may help with the identification of early CAV in patients with impaired perfusion reserve but without angiographically evident atherosclerosis.

Negative pretransplant serostatus for Toxoplasma gondii is associated with impaired survival after heart transplantation.

Chronic Toxoplasma gondii infection is known to trigger potentially adverse immunoregulatory changes, but limited data exist on long-term implications for heart transplant (HTX) recipients. We evaluated the risk of all cause mortality regarding T. gondii serostatus prior to HTX. Pre-HTX T. gondii serostatus was obtained in 344 recipients and 294 donors. Mean age was 52.1 +/- 10.2 years and mean follow-up time after HTX was 5.7 (+/-5.5, median 3.5) years. All seronegative patients received prophylaxis with pyrimethamine/sulfomethoxazole or cotrimoxazol for 6 months after transplantation. Multivariate survival analysis adjusted for diabetes mellitus, pre-HTX renal function, recipient age, type of primary immunosuppression (i.e. HTX before 2001), cytomegalovirus (CMV) high-risk status, ischemic time, and number of treated rejection episodes was performed. Overall, 190 recipients (55.2% of total) were seronegative and 154 (44.8% of total) were seropositive for T. gondii prior to HTX. One hundred and fifty-two recipients died during follow-up (44.2% of total). Negative recipient Toxoplasma serostatus was associated with a significantly higher risk of all-cause mortality (P = 0.0213). Recipient T. gondii serostatus did not influence the number of cellular or humoral rejection episodes. Analyses of specific causes of death showed a trend toward a higher number of infection-related deaths in the seronegative subgroup (P = 0.13). No statistically significant effects of T. gondii donor/recipient seropairing, or seroconversion were observed. Negative preoperative serostatus for T. gondii in HTX recipients appears to be an independent risk factor associated with increased all-cause mortality. The cause of impaired survival in Toxoplasma seronegative recipients is currently unclear; possible explanations include an alteration of immune-reactivity/-regulation or adverse effects of prophylactic medication.

Effects of protein A immunoadsorption in patients with chronic dilated cardiomyopathy.

OBJECTIVES: The objective of this study was to investigate functional effects of immunoadsorption (IA) in patients with chronic nonfamilial dilated cardiomyopathy (DCM) regarding clinical and humoral markers of heart failure. BACKGROUND: IA has been shown to induce early hemodynamic improvement in patients with nonfamilial dilated cardiomyopathy (DCM). METHODS: We performed IA using protein A agarose columns on five consecutive days in 51 patients with chronic DCM, congestive heart failure of NYHA class ≥ II, left ventricular ejection fraction ≤50%, and mean time since initial diagnosis of 5.0 ± 5.8 years. RESULTS: Immediately after IA, immunoglobulin G (IgG) decreased by 89.4% and IgG3 by 66.7% (both P < 0.0001). Median NT-pro BNP was reduced from 1230.0 ng L(-1) at baseline to 829.0 ng L(-1) after 6 months (P < 0.0001). Also mean left ventricular ejection fraction (LVEF) was significantly improved (26.3% ± 9.4% to 28.7% ± 11.4% after 6 months, P = 0.016) and LVEF improved ≥5% (absolute) in 21 of 51 (41.2%) patients. After 6 months, bicycle spiroergometry showed a significant increase in exercise capacity from 82.0 ± 30.8 Watts to 93.1 ± 34.3 Watts (P = 0.008) while VO2max rose from 15.0 ± 4.1 to 16.4 ± 4.8 mL min(-1) kg(-1) (P = 0.01). CONCLUSIONS: In this study, on heart failure patients with nonfamilial DCM, IA therapy significantly improved clinical and humoral markers of heart failure severity. These promising results may be due to the selected study population, with a shorter disease duration and the higher amount of IgG 3 reduction. Future blinded prospective multicenter studies are necessary to identify those patients that benefit most.

Beta2-integrin activation on T cell subsets is an independent prognostic factor in unstable angina pectoris.

BACKGROUND: Cardiac troponins provide excellent risk stratification in unstable angina (UA), but no reliable markers are available in troponin-negative patients. Beta2-integrin mediated T cell recruitment plays a pivotal role in coronary atherosclerotic plaque rupture. The present study investigates beta2-integrin activation on T cell subsets as a risk marker in UA. METHODS: Functional activation (affinity/avidity) of beta2-integrins on T cells was measured using a flow cytometry-based whole blood assay in 87 patients with UA. RESULTS: Beta2-integrin activation was significantly higher in patients with severe coronary artery disease (sC) and myocardial infarction (MI) compared to patients with no/minimal coronary atherosclerosis (no/mC), irrespective of troponin status. Adjusted for cardiovascular risk factors, medication, left ventricular function, MI at enrollment and high sensitivity C-reactive protein (hsCRP), beta2-integrin activation was independently associated with incidence of revascularization, hospitalization and all major cardiovascular events during 9 months of follow-up after index investigation. The highest prognostic value of beta2-integrin activation was seen in troponin-and hsCRP-negative patients. CONCLUSION: Quantitative assessment of T cell beta2-integrin activation allows to identify high risk patients with UA and sC without established MI; furthermore, it is associated with incidence of future cardiovascular events independent of conventional risk factors (troponin, hsCRP).

Effects of protein A immunoadsorption in patients with advanced chronic dilated cardiomyopathy.

OBJECTIVES: The objective of this study was to investigate functional effects of immunoadsorption (IA) in severely limited study patients with chronic nonfamilial dilated cardiomyopathy (DCM), and to analyze the prevalence of Troponin I (TNI) autoantibodies. BACKGROUND: Immunoadsorption (IA) has been shown to induce early hemodynamic improvement in patients with nonfamilial DCM. METHODS: We performed IA using Immunosorba columns on five consecutive days in 27 patients with chronic DCM, congestive heart failure of NYHA class >or=II, left ventricular ejection fraction below 40%, and mean time since initial diagnosis of 7.2 +/- 6.8 years. RESULTS: Immediately after IA, IgG decreased by 87.7% and IgG3 by 58.5%. Median NT-pro BNP was reduced from 1740.0 ng/L at baseline to 1504.0 ng/L after 6 months (P = 0.004). Mean left ventricular ejection fraction (LVEF) was not significantly improved overall (24.1 +/- 7.8% to 25.4 +/- 10.4% after 6 months, P = 0.38), but LVEF improved >or=5% (absolute) in 9 of 27 (33%) patients. Bicycle spiroergometry showed a significant increase in exercise capacity from 73.7 +/- 29.4 Watts to 88.8 +/- 31.1 Watts (P = 0.003) after 6 months while VO2max rose from 13.7 +/- 3.8 to 14.9 +/- 3.0 mL/min kg after 6 months (P = 0.09). Subgroup analysis revealed a higher NT-pro BNP reduction in patients with shorter disease duration (P = 0.03) and without TNI autoantibodies at baseline (P = 0.05). All 9 patients with an absolute increase of LVEF of >or=5.0% were diabetic (P = 0.0001). CONCLUSIONS: In this study, on severely limited heart failure patients with nonfamilial DCM, IA therapy moderately improved markers of heart failure severity in a limited subgroup of patients. This may be due to the selected study population with end-stage heart failure patients and the lower reduction of IgG3 compared to previous studies. Future blinded multicenter studies are necessary to identify those patients that benefit most.

Beneficial effect of omega-3 fatty acids on sirolimus- or everolimus-induced hypertriglyceridemia in heart transplant recipients.

BACKGROUND: Hyperlipidemia is an important complication after organ transplantation and may contribute to the development of posttransplant-accelerated coronary artery disease. Immunosuppressive therapy, especially mammalian target of rapamycin inhibitors, induces a considerable increase in cholesterol and triglyceride plasma levels. Omega-3 fatty acids (FAs) exert cardioprotective effects supporting a therapeutic role in cardiovascular conditions. METHODS: An observational study of omega-3 FAs 4 g/day was performed in 15 heart transplant recipients with hypertriglyceridemia. Six patients received rapamycin, and nine received everolimus. Apart from one patient the immunosuppressive therapy was combined with mycophenolate mofetil, only one patient received steroids; two patients presented with diabetes. RESULTS: Mean triglyceride levels before heart transplantation (HTx) were 137+/-54 mg/dL. After HTx, before sirolimus or everolimus treatment triglyceride level had increased to 188+/-67 mg/dL (P<0.05). Treatment with sirolimus or everolimus induced an increase in triglycerides to 354+/-107 mg/dL (P<0.001). Subsequent treatment with omega-3 FAs for 4 months resulted in a marked decrease in triglycerides to 226+/-74 mg/dL (P<0.001). All patients (100%) showed a reduction in triglyceride by more than 20% (responders). In 10 of 15 patients available 12-month data confirmed the long-term efficacy of omega-3 FAs treatment. There were no adverse events or any discontinuations; no changes in immunosuppression were required. CONCLUSIONS: Treatment with mammalian target of rapamycin inhibitors after HTx induces marked increase in serum levels of triglycerides. Omega-3 FAs significantly lower triglyceride levels and seem to be effective, safe, and well-tolerated in sirolimus- or everolimus-treated heart transplant recipients.

Prophylactic implantation of cardioverter-defibrillator in patients with severe cardiac amyloidosis and high risk for sudden cardiac death.

BACKGROUND: Cardiac light-chain amyloidosis carries a high risk for death predominantly from progressive cardiomyopathy or sudden death (SCD). Independent risk factors for SCD are syncope and complex nonsustained ventricular arrhythmias. OBJECTIVE: The purpose of this study was to test whether prophylactic placement of an implantable cardioverter-defibrillator (ICD) reduces SCD in patients with cardiac amyloidosis. METHODS: Nineteen patients with histologically proven cardiac amyloidosis and a history of syncope and/or ventricular extra beats (Lown grade IVa or higher) received an ICD. RESULTS: During a mean follow-up of 811 +/- 151 days, two patients with sustained ventricular tachyarrhythmias were successfully treated by the ICD. Two patients underwent heart transplantation, and seven patients died due to electromechanical dissociation (n = 6) or glioblastoma (n = 1). Nonsurvivors more often showed progression of left ventricular wall thickness, low-voltage pattern, ventricular arrhythmias (Lown grade IVa or higher), and higher N-terminal pro-brain natriuretic peptide levels than did survivors. Bradycardias requiring ventricular pacing (VVI 40/min <1%, DDD 60/min 6% +/- 1%) occurred only rarely. CONCLUSION: Patients with cardiac amyloidosis predominantly die as a result of electromechanical dissociation and other diagnoses not amenable to ICD therapy. Selected patients with cardiac amyloidosis may benefit from ICD placement. Better predictors of arrhythmia-associated SCD and randomized trials are required to elucidate the impact of ICD placement in high-risk patients with cardiac amyloidosis.

Ezetimibe effectively lowers LDL-cholesterol in cardiac allograft recipients on stable statin therapy.

We investigated tolerability and efficacy of ezetimibe treatment (10 mg/d) in 25 heart allograft recipients already on stable statin therapy. Total cholesterol (TC), low-density cholesterol (LDL-C), high-density cholesterol (HDL-C), triglycerides (TG), immunosuppressant drug levels, laboratory and clinical parameters were assessed before, four months and one yr after initiation of ezetimibe treatment. Mean equivalent statin dose was 53.5 +/- 12.3 mg of pravastatin, remaining unchanged throughout the study period. Ezetimibe was generally well tolerated, only two patients (8%) discontinued ezetimibe due to stomach pain or headache. Mean TC decreased from 231.8 +/- 6.4 mg/dL before therapy to 202.2 +/- 8.8 mg/dL after four months and 192.9 +/- 7.0 mg/dL after one yr (p < 0.001). Mean LDL-C decreased from 143.1 +/- 5.4 mg/dL to 121.4 +/- 7.9 mg/dL (month 4; p < 0.05) and 107.1 +/- 5.6 mg/dL (one yr; p < 0.001). TG decreased from 182 +/- 14.3 mg/dL to 173.3 +/- 17.5 mg/dL after one yr (p < 0.05), whereas HDL-C was unchanged. Initial LDL-C and cardiac diagnosis before transplantation were identified as predictors of absolute LDL-C reduction. Immunosuppressant drug doses and blood concentrations were unchanged as well as other laboratory and clinical parameters. Ezetimibe appears safe and effective for further reduction of TC and LDL-C in heart allograft recipients already on stable statin therapy. Extent of pre-treatment LDL-C and cardiac disorder prior to transplantation appear to correlate with the efficacy of ezetimibe therapy.

Sphingosine-1-phosphate analogue FTY720 causes lymphocyte redistribution and hypercholesterolemia in ApoE-deficient mice.

OBJECTIVE: Resident immune cells are a hallmark of atherosclerotic lesions. The sphingolipid analogue drug FTY720 mediates retrafficking of immune cells and inhibits their homing to inflammatory sites. We have evaluated the effect of FTY720 on atherogenesis and lipid metabolism. METHODS AND RESULTS: ApoE-/- mice on a normal laboratory diet received oral FTY720 for 12 weeks, which led to a 2.4-fold increase in serum cholesterol (largely VLDL fraction) and a 1.8-fold increase in hepatic HMGCoA reductase mRNA. FTY720 increased plasma sphingosine-1-phosphate and induced marked peripheral blood lymphopenia. A discoordinate modulation of B, T and monocyte cell numbers was found in peripheral lymphoid organs. Overall depletion of T cells was accompanied by a relative (2-fold) increase in regulatory T cell content paralleled by a similar increase in effector memory T cells (CD4+ CD44hi CD62lo) as absolute numbers of both subpopulations remained essentially unchanged. Lymphocyte function was unaltered as indicated by anti-OxLDL antibodies and T cell proliferation. There were no changes in atherosclerotic lesions in early and established atherosclerosis. CONCLUSIONS: FTY720 mediated peripheral lymphocyte depletion and retrafficking without altering function and overall balance of pro- and antiatherogenic lymphocyte populations. A net decrease in lymphocyte numbers occurred concomitantly with a more proatherogenic hypercholesterolemia resulting in unaltered atherogenesis.

A sensitive assay for the quantification of integrin-mediated adhesiveness of human stem cells and leukocyte subpopulations in whole blood.

Adhesion of leukocytes is an early step in the formation of adaptive or innate immunity. In chronic inflammatory pathologies like atherosclerosis, regulation of adhesiveness is pivotal for the accumulation of leukocytes within the vessel wall. Therefore, the quantification of adhesion is crucial for the understanding and monitoring of immune responses in patients. However, so far, functional analysis of leukocyte adhesion has been time consuming and required prior purification of cell populations from peripheral blood. This reduced the number of samples and cell populations that could be analysed from limited patient material. Here, we introduce a novel method involving rapid quantification of integrin-mediated leukocyte adhesion in human whole blood using flow cytometry. The quantification relies on soluble multivalent immunocomplexes and is thus called "ligand-complex-based adhesion assay" (LC-AA). LC-AA evaluates both integrin affinity and avidity in T-cells, NK-cells and monocytes from as little as 20 mul of whole blood. In marked contrast to T-cells and NK-cells, unstimulated monocytes show non-blockable background binding of the complexes. Therefore, for this subset only, the stimulation-induced integrin activation is measurable. With the LC-AA, for the first time, measurement of adhesiveness of extremely rare cell populations like CD34+ peripheral blood stem cells can be assessed in the absence of prior purification steps. Finally, the small blood volumes needed for adhesion analysis with the LC-AA allow the evaluation of multiple cell subpopulations in large sample collectives, e.g. required in clinical studies.

Heart rate reduction after heart transplantation with beta-blocker versus the selective If channel antagonist ivabradine.

BACKGROUND: Graft denervation in heart transplant recipients causes sinus tachycardia, occasionally requiring pharmacologic heart rate reduction. The If channel antagonist ivabradine has not been compared to beta-blocker after heart transplantation. Heart rate control, tolerability, short-term safety, and effects on exercise capacity were studied consecutively with an established heart rate-reducing drug (metoprolol succinate) compared to a novel agent (ivabradine) in heart transplant recipients. METHODS: In 25 heart transplant recipients, heart rate, exercise capacity, and patient preference were assessed under no medication (baseline) and after consecutive 8-week treatment periods under metoprolol and ivabradine. RESULTS: Drug discontinuation following side effects occurred in 5 patients (metoprolol: 4, ivabradine: 1); per-protocol analysis was performed on 20 patients completing both consecutive treatment periods. Mean heart rate was reduced from baseline (96.5+/-7.0 bpm) to 84.4+/-8.8 bpm on beta-blocker (P=0.0004 vs. baseline) and to 76.2+/-8.9 bpm with ivabradine (P=0.0001 vs. baseline and P=0.003 vs. beta-blocker). Exercise capacity by spiroergometry was not altered by either drug. Relevant pharmacokinetic interaction with immunosuppressants was not seen under ivabradine; safety laboratory values were unchanged. Mild adverse effects were noted in 45% of patients during beta-blocker and 20% during ivabradine treatment. Questionnaire analysis demonstrated patient preference for heart rate reduction with ivabradine. CONCLUSIONS: Heart rate reduction with ivabradine is effective and potentially better tolerated than beta-blocker therapy in heart transplant recipients. Although the prognostic role of heart rate after HTX is unknown, ivabradine may offer relevant symptomatic benefit, especially in cases of beta-blocker intolerance.

Platelet-associated LIGHT (TNFSF14) mediates adhesion of platelets to human vascular endothelium.

LIGHT (TNFSF 14) belongs to the tumor necrosis factor super-family and is expressed by different types of immune cells. Recently, LIGHT was found to be associated with platelets and released upon activation. Activation of endothelial cells by recombinant LIGHT results in pro-inflammatory and pro-thrombotic changes, qualitatively comparable to effects of CD40 ligand. Given the important role of platelet-associated CD40 ligand in vascular inflammatory responses we investigated the role of LIGHT for activation of endothelium and adhesion of platelets to endothelial cells. Expression of LIGHT was detected on thrombocytes upon exposure to ADP or TRAP-1. The expression of the LIGHT receptors TR2 and LTbetaR on native human endothelial cells was confirmed by FACS analysis. LIGHT mediated adhesion of platelets to endothelium significantly, occurring both under static and dynamic flow conditions. This interaction was inhibited by a monoclonal antibody to LIGHT but not a control IgG. Moreover, in-vitro stimulation of endothelial cells with recombinant soluble human LIGHT (rhLIGHT) resulted in significantly increased transcriptional and translational upregulation of inflammatory markers ICAM-1, tissue factor (TF) and IL-8. This activation of endothelial cells by LIGHT was mediated by NFkappaB activation and qualitatively comparable to that induced by membrane-bound CD40-ligand on transfected cells. Furthermore, plasma levels of patients with myocardial infarction, in those with ST-elevation myocardial infarction (STEMI), showed increased plasma levels of LIGHT compared with healthy controls. In conclusion, platelet-associated LIGHT is involved in adhesion of platelets to endothelium while soluble LIGHT induces a pro-inflammatory state in vascular endothelial cells. LIGHT may thus be implicated in the pathogenesis of atherosclerosis and acute coronary syndrome, as evidenced by serum levels.

MR-relaxometry of myocardial tissue: significant elevation of T1 and T2 relaxation times in cardiac amyloidosis.

OBJECTIVE: This study evaluates if MR-relaxometry of myocardial tissue reveals significant differences in cardiac amyloidosis (CA) compared with patients with systemic amyloidosis but without cardiac involvement (NCA) and a healthy control group. Therefore, we measured T1 and T2 relaxation times (RT) of the left ventricular myocardium with magnetic resonance imaging at 1.5 T. MATERIAL AND METHODS: Nineteen consecutive patients (14 males, 5 females; mean age, 59 +/- 6.1 years) with histologically proven CA were evaluated. T1-RT and T2-RT were measured by using a saturation-recovery TurboFLASH sequence and a HASTE sequence, respectively. Additionally, morphologic and functional data were acquired. Results were compared with patients with systemic amyloidosis but without cardiac involvement (NCA; 5 males, 4 females, 48.9 +/- 15.4 years) and 10 healthy, age-matched control subjects (5 males, 5 females, 60.4 +/- 6.4 years). RESULTS: MR-relaxometry revealed a significant elevation of T1-RT of the left ventricular myocardium in CA-patients compared with that in NCA-patients and the age-matched control group [mean +/- SD (95% CI) 1340 +/- 81 (1303-1376) msec, 1213 +/- 79 (1160-1266) msec, 1146 +/- 71 (1096-1196) msec, respectively; CA vs. control, P < 0.0001; CA vs. NCA:, P < 0.0003; NCA vs. control, P = 0.07]. T2-RT showed a marginal but significant increase in CA-patients compared with NCA-patients and the control group [mean +/- SD (95% CI) 81 +/- 12 (76-86) msec, 71 +/- 11 (64-79) msec, 72 +/- 9 (65-79) msec, respectively; CA vs. control, P = 0.04; CA vs. NCA, P = 0.04; NCA vs. control, P = 0.91]. T1-RT was best suited to discriminate between the groups as shown by logistic regression. A cut-off value of >or=1273 milliseconds for T1-RT was defined using receiver-operator characteristics-analysis to establish the diagnosis of CA with a high sensitivity (84%) and specificity (>89%). CONCLUSIONS: Measurement of T1 and T2 RT is a novel approach for noninvasive evaluation of CA. MR-relaxometry might improve diagnostic reliability of magnetic resonance imaging for evaluation of cardiac involvement in systemic amyloidosis.

Non-invasive predictors of survival in cardiac amyloidosis.

BACKGROUND: Patients with cardiac amyloidosis (CA) have increased mortality. AIMS: Clinical, electrocardiographic, and echocardiographic parameters were assessed for risk-stratification of CA. METHODS AND RESULTS: CA was confirmed by endomyocardial biopsy in 59 patients (54.8+/-1.2 years) with light-chain (n = 43) or transthyretin amyloidosis (n = 16). Six patients without CA served as controls (NCA). Clinical symptoms, electrocardiographic, and echocardiographic parameters were analyzed for prognostic significance. Of the patients with light-chain amyloidosis, 14 died and 2 underwent heart transplantation. 1-/3-year survival was 68%/63%. Survival depended on left ventricular function (LV-EF), LV mass, radius/wall thickness, septum thickness, low voltage pattern (LVP), conduction delay, NYHA class, and stem cell transplantation. A multivariate model only contained LV-EF and LVP; the beneficial effect of stem cell transplantation was cancelled out as this treatment was withheld in patients with highest cardiac risk. Survival was most limited if both risk factors occurred. Cardiac involvement in transthyretin amyloidosis showed better survival (2 deaths, 1-/3-year survival 91%/83%). Analysis of prognostic risk factor utility in all amyloid patients (light-chain and transthyretin) again revealed LVP and LV-EF, and aetiology of amyloidosis as independent survival parameters. CONCLUSION: Prognosis of CA is poor, but aetiology of amyloid, LVP, and LV-EF allows identification of patients at highest risk of death, who may require individual treatment approaches (heart transplantation prior to causative therapy).

Transthyretin valine-94-alanine, a novel variant associated with late-onset systemic amyloidosis with cardiac involvement.

A 63-year-old Caucasian male, diagnosed with dilated cardiomyopathy in 1993, remained clinically stable for several years. In 2003, a marked increase of N-terminal pro-natriuretic peptide serum level (611 ng/ml to 4926 ng/ml) was observed; left ventricular (LV) septum thickness was 10 mm. In addition, sensorimotor polyneuropathy and autonomic dysfunction occurred. Further progression of heart failure occurred despite unchanged systolic LV function. Endomyocardial biopsy in 2006 revealed transthyretin amyloidosis by Congo red and immunohistochemical staining, as well as Val94Ala substitution by transthyretin gene analysis. Cardiac amyloid deposition was quantified by technetium-99m-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scintigraphy. Mutational search of the relatives (n = 1) was unremarkable. The transthyretin Val94Ala mutation is characterized by sensorimotor polyneuropathy, autonomic dysfunction, and gastrointestinal and cardiac involvement with amyloid. This mutation is an addition to the growing spectrum of transthyretin mutations with late onset of clinical symptoms, but noteworthy because of progressive, finally disabling disease course. Final clinical assessment of severity of cardiac involvement in the present patient is rendered complex by possible concomitant or preceding idiopathic dilated cardiomyopathy.