Andreas O Doesch

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.

Cyclosporine withdrawal improves renal function in heart transplant patients on reduced-dose cyclosporine therapy.

Renal failure is a major cause of morbidity after heart transplantation. It is unclear whether calcineurin inhibitor (CNI) free immunosuppression provides more nephroprotection than low‐dose CNI therapy. Thirty‐nine patients with renal failure on low‐dose cyclosporine A (CsA) were studied (62.9 ± 8.7 years, five female, 8.2 ± 4.3 years posttransplant, serum creatinine: 1.9 ± 0.3 mg/dL, calculated GFR (cGFR): 48.2 ± 18.3 mL/min, CsA C0 level: 64.0 ± 19.9 ng/mL). All patients had been treated with low‐dose CsA >6 months, renal function was stable or slowly decreasing (creatinine 1.7–3.5 mg/dL). Nineteen patients were randomized to discontinuation of CsA and overlapping rapamycin therapy initiation (RAPA), 20 patients continued low‐dose CsA (control). Three patients (16%) discontinued rapamycin medication for side effects (diarrhea, skin rash), two patients developed pneumonia and pulmonary embolism, respectively, no rejection or other infectious complications were seen. After 6 months, renal function in the control group was unchanged. In the RAPA group, renal function markedly improved (creatinine: 2.08 ± 0.15 to 1.67 ± 0.13 mg/dL, cGFR: 48.5 ± 21.4 to 61.7 ± 21.4 mL/min (p < 0.001 within and between groups)). In carefully selected late survivors following heart transplantion who are at low risk of rejection, CNI‐free rapamycin‐based immunosuppression improves cGFR even in those already receiving low‐dose CsA therapy. The results of this study warrant further confirmation in larger clinical trials that are powered to assess clinical outcomes.

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.

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.

CXCL4-induced plaque macrophages can be specifically identified by co-expression of MMP7+S100A8+in vitro and in vivo

Macrophage heterogeneity in human atherosclerotic plaques has been recognized; however, markers for unequivocal identification of some subtypes are lacking. We found that the platelet chemokine CXCL4 induces a unique macrophage phenotype, which we proposed to call ‘M4’. Here, we sought to identify suitable markers that identify M4 macrophages in vitro and in vivo. Using a stringent algorithm, we identified a set of potential markers from transcriptomic data derived from polarized macrophages. We specifically focused on matrix metalloproteinase (MMP)7 and S100A8, the co-expression of which has not been described in any macrophage type thus far. We found dose- and time-dependent MMP7 and S100A8 expression in M4 macrophages at the gene and protein levels. CXCL4-induced up-regulation of both MMP7 and S100A8 was curbed in the presence of heparin, which binds to CXCL4 and glycosaminoglycans, most likely representing the macrophage receptor for CXCL4. Immunofluorescence of post-mortem atherosclerotic coronary arteries identified CD68+MMP7+, CD68+MMP7−, CD68+S100A8+ and CD68+S100A8− macrophages. A small proportion of MMP7+S100A8+ macrophages most likely represent M4 macrophages. In summary, we have identified co-expression of MMP7 and S100A8 to be a marker combination exclusively found in M4 macrophages. This finding may allow further dissection of the role of M4 macrophages in atherosclerosis and other pathologic conditions.

Increased Adherence after Switch From Twice Daily Calcineurin Inhibitor Based Treatment to Once Daily Modified Released Tacrolimus in Heart Transplantation: A Pre-experimental Study

BACKGROUND Modified release tacrolimus (TAC) is a new, once-daily oral formulation of the established immunosuppressive agent TAC. Simplification of regimen has been associated with better adherence. This study evaluated patient adherence, as well as safety and efficacy among chronic stable heart transplantation (HT) patients switched from a conventional twice daily calcineurin inhibitor-based regimen (TAC or cyclosporine A [CsA]) to (once daily) modified release TAC. METHODS We switched 54 chronic stable patients (41 males and 13 females) from twice daily dosing with conventional TAC or CsA to once daily dosing with modified release TAC. Self-reported adherence was assessed at baseline and at 4 months after the switch using the Basel Assessment of Adherence with Immunosuppressive Medication Scale [BAASIS]), a 4-item validated questionnaire including also a Visual Analogue Scale (VAS). Nonadherence was defined as any self-reported nonadherence on any item. RESULTS Modified release TAC was discontinued in 4 patients because of diarrhea (n = 1) or gastrointestinal discomfort (n = 3) leaving 50 evaluable patients. Overall nonadherence at baseline for any of the 4 items was 74% versus 38% after 4 months (P = .0001). Thereafter, adherence improved in 28 patients (56.0%), was unchanged in 18 (36.0%), and decreased in 4 subjects (8.0%). The VAS score improved from 82.3% ± 2.6% to 97.5% ± 4.8% (P < .0001). No significant changes were observed after 4 months regarding hematologic, renal, or liver function parameters (all P = NS). CONCLUSIONS Therapeutic regimens for transplant recipients are often complex, contributing to a high incidence of medication nonadherence. This study in chronic, stable, heart transplantation patients demonstrated a significant improvement in patient adherence after a switch to modified release TAC, which was generally well tolerated.

Pharmacodynamic cyclosporine A-monitoring: relation of gene expression in lymphocytes to cyclosporine blood levels in cardiac allograft recipients.

Recently, we established a pharmacodynamic assay to monitor immunosuppressive effectiveness of cyclosporine A (CsA) in patients on standard CsA regimen. The aim of the present study was to extend this correlation to reduced CsA regimen and to compare pharmacodynamic and kinetic parameters to allow prediction of rejections and infections. In 53 heart allograft recipients, nuclear factor of activated T cells (NFAT)‐regulated gene expression was quantified at trough (C0) and 2‐h post‐CsA dose (C2). Gene expression at C2 was calculated relative to C0 (residual gene expression, RGE) or relative to a healthy reference group (absolute gene expression, AGE). RGE correlated with CsA C2‐levels in bimodal fashion: above 575 ng/ml correlation was seen with flat regression gradient. Below 575 ng/ml, correlation was excellent with markedly steeper gradient. At C0 in the low‐C2 group (<575 ng/ml), AGE remained unchanged, whereas in the high‐C2 group (>575 ng/ml) AGE was markedly reduced. In both groups, AGE at C2 was strongly inhibited. In patients contracting infection during follow‐up, RGE was lower than in those without infections independent of CsA levels. CsA‐monitoring by quantitation of NFAT‐regulated gene expression is feasible with standard and reduced CsA regimens. It correlates better with the incidence of infections than measurement of CsA concentrations and might help in avoiding over‐immunosuppression.

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

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.

The association between long-term longitudinal trends in guideline adherence and mortality in relation to age and sex

Using a large clinical multi‐site prospective chronic heart failure registry, we sought to determine (i) implementation of guidelines over time and (ii) adjusted survival benefit there from.

Heart rate reduction for 12 months with ivabradine reduces left ventricular mass in cardiac allograft recipients.

Background. Graft denervation in heart transplant recipients causes sinus tachycardia, occasionally requiring pharmacologic heart rate reduction. Currently, no 12-month data regarding effects of the novel If channel antagonist ivabradine on heart rate control, effects on left ventricular mass, tolerability, and safety are available in patients after heart transplantation (HTX). Methods. Mean heart rate, left ventricular mass indexed (LVMI) to body surface area, tolerability, and safety of ivabradine therapy were evaluated at baseline and after 12 months in 30 HTX recipients with marked sinus tachycardia. Results. In three patients (10.0% of total), ivabradine medication was discontinued. Further analysis was based on 27 patients with 12-month drug exposure. Mean patient age was 53.3±11.3 years, and mean time after HTX was 5.0±4.8 years. Mean ivabradine dose was 12.5 mg/day (±3.3 mg). Mean heart rate was reduced from 96.2±8.6 beats per minute (bpm) at baseline to 80.9±8.1 bpm at follow-up (P<0.0001). A statistically significant effect of heart rate reduction on LVMI was observed (104.3±22.7 g at baseline vs. 95.9±18.5 g at follow-up, P=0.04). No statistically significant changes in immunosuppressive drug dosage or blood levels were observed, except from a lower mycophenolate mofetil dose at follow-up (P=0.01). Safety laboratory values were unchanged. No phosphenes were observed. Conclusions. Heart rate reduction with ivabradine is effective and safe in heart transplant recipients. After 12 months, significant effects on LVMI were observed. Therefore, ivabradine may offer a beneficial effect on left ventricular remodelling in HTX patients.