Therapeutic effect of immunoadsorption and subsequent immunoglobulin substitution in patients with dilated cardiomyopathy: Results from the observational prospective Bad Berka Registry

State-of-the-art document on optimal contemporary management of cardiomyopathies

Cardiomyopathies represent significant contributors to cardiovascular morbidity and mortality. Over the past decades, a progress has occurred in characterization of the genetic background and major pathophysiological mechanisms, which has been incorporated into a more nuanced diagnostic approach and risk stratification. Furthermore, medications targeting core disease processes and/or their downstream adverse effects have been introduced for several cardiomyopathies. Combined with standard care and prevention of sudden cardiac death, these novel and emerging targeted therapies offer a possibility of improving the outcomes in several cardiomyopathies. Therefore, the aim of this document is to summarize practical approaches to the treatment of cardiomyopathies, which includes the evidence-based novel therapeutic concepts and established principles of care, tailored to the individual patient aetiology and clinical presentation of the cardiomyopathy. The scope of the document encompasses contemporary treatment of dilated, hypertrophic, restrictive and arrhythmogenic cardiomyopathy. It was based on an expert consensus reached at the Heart Failure Association online Workshop, held on 18 March 2021.

The Molecular Role of Immune Cells in Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is a rare and severe condition characterized by chamber dilation and impaired contraction of the left ventricle. It constitutes a fundamental etiology for profound heart failure and abrupt cardiac demise, rendering it a prominent clinical indication for heart transplantation (HTx) among both adult and pediatric populations. DCM arises from various etiologies, including genetic variants, epigenetic disorders, infectious insults, autoimmune diseases, and cardiac conduction abnormalities. The maintenance of cardiac function involves two distinct types of immune cells: resident immune cells and recruited immune cells. Resident immune cells play a crucial role in establishing a harmonious microenvironment within the cardiac tissue. Nevertheless, in response to injury, cardiomyocytes initiate a cytokine cascade that attracts peripheral immune cells, thus perturbing this intricate equilibrium and actively participating in the initiation and pathological remodeling of dilated cardiomyopathy (DCM), particularly during the progression of myocardial fibrosis. Additionally, immune cells assume a pivotal role in orchestrating the inflammatory processes, which are intimately linked to the prognosis of DCM. Consequently, understanding the molecular role of various immune cells and their regulation mechanisms would provide an emerging era for managing DCM. In this review, we provide a summary of the most recent advancements in our understanding of the molecular mechanisms of immune cells in DCM. Additionally, we evaluate the effectiveness and limitations of immunotherapy approaches for the treatment of DCM, with the aim of optimizing future immunotherapeutic strategies for this condition.

Identification of Immune Markers in Dilated Cardiomyopathies with Heart Failure by Integrated Weighted Gene Coexpression Network Analysis

Dilated cardiomyopathy (DCM), a heterogeneous cardiomyopathy, is a major cause of heart failure and heart transplant. Currently, immunotherapy is believed to be an effective treatment method for DCM. However, individual differences are so obvious that the clinical effect is not satisfactory. In order to find immune-related biomarkers of DCM to guide treatment and improve clinical efficacy, we downloaded a GSE120895 dataset from the Gene Expression Omnibus (GEO) database using CIBERSORT and WGCNA algorithms in RStudio and visualizing the protein–protein interaction (PPI) network for key modules by Cytoscape, and finally obtained six hub genes. A GSE17800 dataset was downloaded from the GEO dataset to verify the diagnostic values of hub genes, MYG1, FLOT1, and ATG13, which were excellent. Our study revealed unpublished potential immune mechanisms, biomarkers, and therapeutic targets of DCM.

Mechanisms of Neutralizing Anti-drug Antibody Formation and Clinical Relevance on Therapeutic Efficacy of Enzyme Replacement Therapies in Fabry Disease

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by mutations in the α-galactosidase A (AGAL/GLA) gene. The lysosomal accumulation of the substrates globotriaosylceramide (Gb₃) and globotriaosylsphingosine (lyso-Gb₃) results in progressive renal failure, cardiomyopathy associated with cardiac arrhythmia, and recurrent strokes, significantly limiting life expectancy in affected patients. Current treatment options for FD include recombinant enzyme-replacement therapies (ERTs) with intravenous agalsidase-α (0.2 mg/kg body weight) or agalsidase-β (1 mg/kg body weight) every 2 weeks, facilitating cellular Gb₃ clearance and an overall improvement of disease burden. However, ERT can lead to infusion-associated reactions, as well as the formation of neutralizing anti-drug antibodies (ADAs) in ERT-treated males, leading to an attenuation of therapy efficacy and thus disease progression. In this narrative review, we provide a brief overview of the clinical picture of FD and diagnostic confirmation. The focus is on the biochemical and clinical significance of neutralizing ADAs as a humoral response to ERT. In addition, we provide an overview of different methods for ADA measurement and characterization, as well as potential therapeutic approaches to prevent or eliminate ADAs in affected patients, which is representative for other ERT-treated lysosomal storage diseases.

HMG-CoA Reductase Inhibitor, Simvastatin Is Effective in Decreasing Degree of Myocarditis by Inhibiting Metalloproteinases Activation

Background: Acute myocarditis often progresses to heart failure because there is no effective, etiology-targeted therapy of this disease. Simvastatin has been shown to be cardioprotective by decreasing matrix metalloproteinases’ (MMPs) activity. The study was designed to determine whether simvastatin inhibits MMPs activity, decreases the severity of inflammation and contractile dysfunction of the heart in experimental autoimmune myocarditis (EAM). Methods: Simvastatin (3 or 30 mg/kg/day) was given to experimental rats with EAM by gastric gavage for 21 days. Then transthoracic echocardiography was performed, MMPs activity and troponin I level were determined and tissue samples were assessed under a light and transmission electron microscope. Results: Hearts treated with simvastatin did not show left ventricular enlargement. As a result of EAM, there was an enhanced activation of MMP-9, which was significantly reduced in the high-dose simvastatin group compared to the low-dose group. It was accompanied by prevention of myofilaments degradation and reduction of severity of inflammation. Conclusions: The cardioprotective effects of simvastatin in the acute phase of EAM are, at least in part, due to its ability to decrease MMP-9 activity and subsequent decline in myofilaments degradation and suppression of inflammation. These effects were achieved in doses equivalent to therapeutic doses in humans.

From combined heart-kidney to kidney transplantation program: what nephrologists should know about dilated cardiomyopathy

A 42-year-old hemodialysis (HD) patient was investigated in our department for symptomatic heart failure (HF) despite daily home dialysis. He had a history of living donor kidney transplantation at the age of 18 that lasted 7 years. Home dialysis was then started. At the age of 40, he developed acute heart failure symptoms. Echocardiography revealed severe dilated cardiomyopathy (DCM). Coronarography and myocardial perfusion scintigraphy showed no abnormal findings. Betablockers were administrated, and RAAS inhibitor dosing was optimized. Dyspnea persisted, and patient was referred to our department. At admission, blood pressure was 116/82 mmHg, and pulse 68 beats/min. No peripheral edema was observed. Dry weight was 62.5 kg. Patient was anuric. Hemoglobin level was 9.8 g/dl, highly sensitive troponin level was 62 ng/ml, and BNP level was 1527 ng/ml. The liver enzyme levels were normal. C-reactive protein was 4.2 mg/ml. Vitamin level, zinc levels, and thyroid function were normal.

Immunoadsorption treatment for dilated cardiomyopathy: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

As one of the leading causes of heart failure, dilated cardiomyopathy (DCM) is characterized by dysfunctional muscle contraction and enlarged ventricular chamber. Patients with DCM have been shown to respond well to immunoadsorption (IA) therapies. However, the efficacy and safety of IA treatment for DCM patients remained to be evaluated.

METHODS

This study was designed in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis. We searched the databases such as Cochrane library, Cochrane Central Register of Controlled Trials, Embase, OVID, and Web of Science from January 1990 to March 20, 2020, and performed meta-analysis using Stata MP Version 13.0.

RESULTS

We performed meta-analysis on 12 studies that included a total of 395 patients with DCM. Overall, IA treatment significantly improved the left ventricular ejection fraction (6.01, 95% confidence interval [CI] [4.84-7.19]), reduced the left ventricular end diastolic diameter (-3.62, 95% CI [-4.06 to -3.19]), reduced severity of symptoms according to the New York Heart Association (NYHA) functional classification (-1.37, 95% CI [-1.73 to -1.02]) as compared with the controls, but had no effect on values for safety parameters (1.13, 95% CI [0.58-2.19]).

CONCLUSIONS

Results of this meta-analysis indicated that the IA treatment can improve the left ventricular ejection fraction, reduce left ventricular end diastolic diameter, and thus improve clinical outcome in DCM patients. However, further evidence are required to validate the relative safety of IA treatment. Multi-center, double blind studies should be conducted to elucidate the precise effect of IA treatment in DCM patients.

Performance, clinical effectiveness, and safety of immunoadsorption in a wide range of indications

Immunoadsorption is well known to selectively remove immunoglobulins and immune complexes from plasma and is applied in a variety of autoimmune diseases and for desensitization before, or at acute rejection after organ transplantation. Performance, safety, and clinical effectiveness of immunoadsorption were the aim of this study. This prospective, noninterventional, multicentre cohort study included patients treated with immunoadsorption (Immunosorba or GLOBAFFIN adsorbers) for any indication. Clinical effectiveness was assessed after termination of the patient's individual treatment schedule. Eighty‐one patients were included, 69 were treated with Immunosorba, 11 with GLOBAFFIN, one patient with both adsorbers. A majority of patients was treated for neurological indications, dilated cardiomyopathy, and before or after kidney or heart transplantation. Mean IgG reduction from pre‐ to post‐treatment was 69.9% ± 11.5% for Immunosorba and 74.1% ± 5.0% for GLOBAFFIN, respectively. The overall IgG reduction over a complete treatment block was 68%–93% with Immunosorba and 62%–90% with GLOBAFFIN depending on the duration of the overall treatment. After termination of the immunoadsorption therapy, an improvement of clinical status was observed in 63.0%, stabilization of symptoms in 29.6%, and a deterioration in 4.9% of patients. Changes in fibrinogen, thrombocytes, and albumin were mostly classified as noncritical. Overall, the treatments were well tolerated. Immunoadsorption in routine clinical practice with both GLOBAFFIN and Immunosorba has been safely performed, was well tolerated by patients, and effective in lowering immunoglobulins with an improvement or maintenance of clinical status, thus represents an additional therapeutic option for therapy refractory immune disorders.

β1-Adrenoreceptor Autoantibodies in Heart Failure: Physiology and Therapeutic Implications

Antibodies that activate the β₁-AR (β₁-adrenoreceptor) can induce heart failure in animal models. These antibodies are often found in patients with heart failure secondary to varying etiologies. Their binding to the β₁ receptor leads to prolonged receptor activation with subsequent induction of cellular dysfunction, apoptosis, and arrhythmias. β-blocker therapy while highly effective for heart failure, may not be sufficient treatment for patients who have β₁ receptor autoantibodies. Removal of these autoantibodies by immunoadsorption has been shown to improve heart failure in small studies. However, immunoadsorption is costly, time consuming, and carries potential risks. An alternative to immunoadsorption is neutralization of autoantibodies through the intravenous application of small soluble molecules, such as peptides or aptamers, which specifically target and neutralize β₁-AR autoantibodies. Peptides may induce immunogenicity. Animal as well as early phase human studies with aptamers have not shown safety concerns to date and have demonstrated effectiveness in reducing autoantibody levels. Novel aptamers have the potential advantage of having a wide spectrum of action, neutralizing a variety of known circulating G-protein coupled receptor autoantibodies. These aptamers, therefore, have the potential to be novel therapeutic option for patients with heart failure who have positive for β₁-AR autoantibodies. However, clinical outcomes trials are needed to assess the clinical utility of this novel approach to treat heart failure.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Use of Cardiac Biomarkers for Monitoring Improvement of Left Ventricular Function by Immunoadsorption Treatment in Dilated Cardiomyopathy

Immunoadsorption and subsequent administration of intravenous immunoglobulin (IVIG) have shown beneficial effects on cardiac function and symptoms in patients with dilated cardiomyopathy. Biomarkers play an emerging role in disease monitoring and outcome prediction of heart failure (HF) patients. We aimed to analyze cardiac biomarkers as predictor for improvement of left ventricular (LV) function after immunoadsorption treatment in dilated cardiomyopathy (DCM). Thirty-one patients with dilated cardiomyopathy on optimized HF pharmacotherapy received a single cycle of immunoadsorption for five days followed by IVIG administration. Left ventricular ejection fraction (LVEF) and heart failure biomarkers (hs troponin T, hs troponin I, NT-proBNP and sST2) were evaluated before treatment, after the last cycle of immunoadsorption and during a median follow-up of 30.5 months. We correlated HF biomarkers before immunoadsorption and acute changes of HF biomarkers by immunoadsorption with LV improvement during the long-term follow-up. LV function improved significantly after immunoadsorption from 28.0 to 42.0% during the long-term follow-up (p < 0.0001). Evaluation of biomarker levels showed a significant decrease for hs troponin I (from 9.2 to 5.5 ng/L, p < 0.05) and NT-proBNP (from 789.6 to 281.2 pg/mL, p < 0.005). Correlation of biomarker levels before immunoadsorption and LVEF at the long-term follow-up show good results for hs troponin T (r = −0.40, r² = 0.16, p < 0.05), hs troponin I (r = −0.41, r² = 0.17, p < 0.05) and sST2 (r = −0.46, r² = 0.19, p < 0.05). Correlation of biomarker levels before immunoadsorption and the individual increase in LV function was significant for hs troponin T (r = −0.52, r² = 0.27, p < 0.005) and hs troponin I (r = −0.53, r² = 0.29, p < 0.005). To imply a tool for monitoring outcome immediately after immunoadsorption treatment, we investigated the correlation of acute changes of biomarker levels by immunoadsorption treatment and individual increase in LV function. A drop in hs troponin T (r = −0.41, r² = 0.17, p < 0.05) and hs troponin I (r = −0.53, r² = 0.28, p < 0.005) levels demonstrate a good correlation to improvement in LVEF during the long-term follow-up. Conclusion: Hs troponin T and I levels correlate with LV function improvement during long-term follow-up. Acute decrease of troponins by immunoadsorption treatment is paralleled by individual improvement of LVEF at the long-term follow-up. Thus, troponins could serve as a monitoring tool for the improvement of LV function after immunoadsorption treatment in dilated cardiomyopathy.

Increased circulating IgG levels, myocardial immune cells and IgG deposits support a role for an immune response in pre- and end-stage heart failure

The chronic inflammatory response plays an important role in adverse cardiac remodelling and the development of heart failure (HF). There is also evidence that in the pathogenesis of several cardiovascular diseases, chronic inflammation is accompanied by antibody and complement deposits in the heart, suggestive of a true autoimmune response. However, the role of antibody‐mediated immune responses in HF progression is less clear. We assessed whether immune cell infiltration and immunoglobulin levels are associated with HF type and disease stage, taking sex differences into account. We found IgG deposits and increased infiltration of immune cells in the affected myocardium of patients with end‐stage HF with reduced ejection fraction (HFrEF, n = 20). Circulating levels of IgG1 and IgG3 were elevated in these patients. Furthermore, the percentage of transitional/regulatory B cells was decreased (from 6.9% to 2.4%) compared with healthy controls (n = 5). Similarly, increased levels of circulating IgG1 and IgG3 were observed in men with left ventricular diastolic dysfunction (LVDD, n = 5), possibly an early stage of HF with preserved EF (HFpEF). In conclusion, IgG deposits and infiltrates of immune cells are present in end‐stage HFrEF. In addition, both LVDD patients and end‐stage HFrEF patients show elevated levels of circulating IgG1 and IgG3, suggesting an antibody‐mediated immune response upon cardiac remodelling, which in the early phase of remodelling appear to differ between men and women. These immunoglobulin subclasses might be used as marker for pre‐stage HF and its progression. Future identification of auto‐antigens might open possibilities for new therapeutic interventions.

Add-on Immunoadsorption Shortly-after Optimal Medical Treatment Further Significantly and Persistently Improves Cardiac Function and Symptoms in Recent-Onset Heart Failure-A Single Center Experience

Background: Immunoadsorption and intravenous immunoglobulin (IVIG) administration may have beneficial effects in patients with dilated cardiomyopathy with end-stage heart failure. We investigated the effect of immunoadsorption with subsequent IVIG administration on cardiac function and symptoms in patients on optimal medical treatment (OMT) for heart failure (HF) with recent-onset cardiomyopathy during long-term follow-up. Methods: Thirty-five patients with recent-onset of HF symptoms received intensive guideline-recommended medical HF therapy for 5.2 months. Subsequently, all patients received a single cycle of immunoadsorption for five days followed by IVIG administration. During the 29-month follow-up period, New York Heart Association (NYHA) functional class, left ventricular ejection fraction (LVEF) and N-terminal pro brain natriuretic peptide (NT-proBNP) were evaluated. Changes in quality of life (QoL) were assessed using the Minnesota Living with HF Questionnaire. Results: Three months after immunoadsorption, NYHA functional class improved from 2.0 to 1.5 (p < 0.005) and LVEF significantly increased from 27.0% to 39.0% (p < 0.0001). Long-term follow-up of 29 months showed stable NYHA functional class and a further moderate increase in LVEF from 39.0% to 42.0% (p < 0.0001) accompanied by a significant improvement in NT-proBNP and QoL scores. Conclusion: Immunoadsorption followed by IVIG administration further enhances LVEF, HF symptoms, QoL and biomarkers in patients with recent-onset HF on OMT.

[Inflammatory cardiomyopathy and myocarditis]

We describe diagnosis, differential diagnosis, multimodality imaging and medical and invasive diagnostic treatment in patients with inflammatory cardiomyopathy and myocarditis under etiological considerations in reference to a landmark position paper of the Working Group Myocardial and Pericardial Diseases of the European Society of Cardiology together with recent developments in diagnosis and treatment. Diagnosis of the symptomatic patient is the assessment of etiology of inflammatory cardiomyopathy, followed by the clinical presentation, course, treatment option and prognosis. Viral myocarditis in its different facets can clearly be separated from autoreactive forms by histological and molecular methods in the endomyocardial biopsy, thus leading to an individualized targeted therapy beyond heart failure treatment.

Safety and Efficacy of Immunoadsorption as an Add-On to Medical Treatment in Patients with Severe Idiopathic Pulmonary Arterial Hypertension

BACKGROUND

Despite optimized medical therapy, severe idiopathic pulmonary arterial hypertension (IPAH) is a devastating disease with a poor outcome. Autoantibodies have been detected in IPAH that can contribute to worsening of the disease.

OBJECTIVES

The objective of this prospective, open-label, single-arm, multicenter trial was to evaluate the safety and efficacy of immunoadsorption (IA) as an add-on to optimized medical treatment for patients with IPAH.

METHODS

A total of 10 IPAH patients received IA over 5 days. Their clinical parameters, including hemodynamics measured by right heart catheter, were assessed at baseline and after 3 and 6 months. The primary endpoint was the change in pulmonary vascular resistance (PVR). Secondary endpoints included the change in 6-min walking distance, quality of life, safety, and plasma levels of IgG and autoantibodies.

RESULTS

The evaluation of the 10 IPAH patients (75% female; 51 ± 12 years; 166 ± 10 cm; WHO functional class III; 53% on combination therapy) revealed that IA was a safe procedure that efficiently removed IgG and autoantibodies from the circulation. After 3 months, the mean PVR improved significantly by 13.2% (p = 0.03) and the cardiac index improved by 13.1%, but no significant changes were found in 6-min walking distance. The quality of life physical functioning subscale score significantly improved after 6 months. The serious adverse events in 3 patients were possibly related to IA and included pneumonia, temporary disturbance in attention, and thrombocytopenia.

CONCLUSIONS

IA as an add-on to targeted medical treatment for IPAH is a safe procedure with beneficial effects on hemodynamics, especially in patients with high levels of autoantibodies. Larger-scale controlled studies are needed to assess its efficacy in IPAH and to identify responders.

Natural products with anti-inflammatory and immunomodulatory activities against autoimmune myocarditis

Myocarditis is an inflammatory disease of the myocardium associated with immune dysfunction which may frequently lead to the development of dilated cardiomyopathy. Experimental autoimmune myocarditis is an animal model which mimics myocarditis in order to allow assessment of the therapeutic effects of different molecules on this disease. We aimed to review the inflammatory and immunological mechanisms involved in the pathogenesis of the myocarditis and finding natural products and phytochemicals with anti-myocarditis activities based on studies of cardiac myosin-induced experimental autoimmune myocarditis in rodents. A number of natural molecules (e.g. apigenin, berberine and quercetin) along with some plant extracts were found to be effective in alleviating experimental autoimmune myocarditis. Upregulation of Th1-type cytokines and elevation of the Th2-type cytokines (IL-4 and IL-10), mitigation of oxidative stress, modulation of mitogen-activated protein kinase signaling pathways and increasing Sarco-endoplasmic reticulum Ca²⁺-ATPase levels are among the most important anti-myocarditis mechanisms for the retrieved molecules and extracts. Interestingly, there are structural similarities between the anti-EAM compounds, suggesting the presence of similar pharmacophore and enzymatic targets for these molecules. Naturally occurring molecules discussed in the present article are potential anti-myocarditis drugs and future additional animal studies and clinical trials would shed more light on their effectiveness in the treatment of myocarditis and prevention of dilated cardiomyopathy.