Japanese Antibacterial Drug Management for Cardiac Sarcoidosis (J-ACNES): A multicenter, open-label, randomized, controlled study

Cardiac sarcoidosis; update for the heart failure specialist

PURPOSE OF REVIEW

This review presents contemporary data on epidemiology, common presentations, investigations and diagnostic algorithms, treatment and prognosis. It particularly focuses on topics of most relevance to heart failure specialists, including what left ventricle (LV) function changes can be expected after treatment and outcomes to all standard and advanced heart failure therapies.

RECENT FINDINGS

Around 5% of sarcoidosis patients have clinically manifest cardiac sarcoidosis (CS), presenting with significant arrhythmias (such as conduction disturbances and ventricular arrhythmias) or newly developed unexplained heart failure. These cardiac symptoms (including sudden cardiac death) may be the initial manifestations of CS. While cardiac magnetic resonance imaging (CMR) is the preferred method for identifying fibrosis in the myocardium, FDG-positron emission tomography (FDG-PET) helps in identifying active inflammation within the myocardium and aids in managing immunosuppressive treatment. The concept of isolated CS is much debated. However very importantly, recent data have shown that some patients diagnosed with 'clinically and imaging isolated CS' are subsequently found to have genetic cardiomyopathy. The management of CS involves a comprehensive approach including medications for immunosuppression, all standard heart failure medication and, in high-risk patient's implantable cardioverter defibrillators (ICDs). In CS patients with terminal heart failure who do not respond to medical and surgical interventions, heart transplantation and ventricular assist devices should be considered. Long-term results after transplantation are generally favorable and comparable to non-CS patients. The degree of left ventricular dysfunction remains a crucial prognostic factor in CS cases. Outcomes for CS have very significantly improved, over the last two decades due to earlier diagnosis, advanced heart failure treatments, and the strategic use of ICD therapy.

SUMMARY

Outcomes for CS have significantly improved, over the last two decades due to earlier diagnosis, advanced heart failure treatments, and the strategic use of ICD therapy.

Gut-Heart Axis: Microbiome Involvement in Restrictive Cardiomyopathies

An intriguing aspect of restrictive cardiomyopathies (RCM) is the microbiome role in the natural history of the disease. These cardiomyopathies are often difficult to diagnose and so result in significant morbidity and mortality. The human microbiome, composed of billions of microorganisms, influences various physiological and pathological processes, including cardiovascular health. Studies have shown that gut dysbiosis, an imbalance in the composition of intestinal bacteria, can contribute to systemic inflammation, a key factor in many cardiovascular conditions. An increase in gut permeability, frequently caused by dysbiosis, allows bacterial endotoxins to enter the bloodstream, activating inflammatory pathways that exacerbate cardiac dysfunction. Recent reports highlight the potential role of microbiome in amyloidogenesis, as certain bacteria produce proteins that accelerate the formation of amyloid fibrils. Concurrently, advancements in amyloidosis treatments have sparked renewed hopes, marking a promising era for managing these kinds of diseases. These findings suggest that the gut-heart axis may be a potential factor in the development and progression of cardiovascular disease like RCM, opening new paths for therapeutic intervention. The aim of this review is to provide a detailed overview of the gut-heart axis, focusing on RCM.

Novel Therapeutics and Upcoming Clinical Trials Targeting Inflammation in Cardiovascular Diseases

Cardiovascular disease (CVD) remains a major health burden despite significant therapeutic advances accomplished over the last decades. It is widely and increasingly recognized that systemic inflammation not only represents a major cardiovascular risk and prognostic factor but also plays key pathogenic roles in CVD development and progression. Despite compelling preclinical evidence suggesting large potential of anti-inflammatory pharmacological interventions across numerous CVDs, clinical translation remains incomplete, mainly due to (1) yet undefined molecular signaling; (2) challenges of safety and efficacy profile of anti-inflammatory drugs; and (3) difficulties in identifying optimal patient candidates and responders to anti-inflammatory therapeutics, as well as optimal therapeutic windows. Randomized controlled trials demonstrated the safety/efficacy of canakinumab and colchicine in secondary cardiovascular prevention, providing confirmation for the involvement of a specific inflammatory pathway (NLRP3 [NACHT, LRR, and PYD domain-containing protein 3] inflammasome/IL [interleukin]-1β) in atherosclerotic CVD. Colchicine was recently approved by the US Food and Drug Administration for this indication. Diverse anti-inflammatory drugs targeting distinct inflammatory pathways are widely used for the management of other CVDs including myocarditis and pericarditis. Ongoing research efforts are directed to implementing anti-inflammatory therapeutic strategies across a growing number of CVDs, through repurposing of available anti-inflammatory drugs and development of novel anti-inflammatory compounds, which are herein concisely discussed. This review also summarizes the main characteristics and findings of completed and upcoming randomized controlled trials directly targeting inflammation in CVDs, and discusses major challenges and future perspectives in the exciting and constantly expanding landscape of cardioimmunology.

Cardiac Sarcoidosis Which Occurred Four Years after Successful Treatment of Cutaneous Sarcoidosis with Minocycline

A 67-year-old woman was admitted to our hospital because of a complete right bundle branch block. She had been treated with minocycline for skin sarcoidosis and her symptoms had ameliorated four years previously. Gallium scintigraphy revealed an abnormal uptake in the heart but not in the skin or lungs. She was diagnosed with cardiac sarcoidosis, although an endomyocardial biopsy could not detect any sarcoid lesions. Immunohistochemical staining for Cutibacterium acnes was positive for granulomas of the skin lesions which had been previously biopsied. One year after starting the administration of steroids, her condition improved.

New insights gained from cellular landscape changes in myocarditis and inflammatory cardiomyopathy

Advances in the etiological classification of myocarditis and inflammatory cardiomyopathy (ICM) have reached a consensus. However, the mechanism of myocarditis/ICM remains unclear, which affects the development of treatment and the improvement of outcome. Cellular transcription and metabolic reprogramming, and the interactions between cardiomyocytes and non-cardiomyocytes, such as the immune cells, contribute to the process of myocarditis/ICM. Recent efforts have been made by multi-omics techniques, particularly in single-cell RNA sequencing, to gain a better understanding of the cellular landscape alteration occurring in disease during the progression. This article aims to provide a comprehensive overview of the latest studies in myocarditis/ICM, particularly as revealed by single-cell sequencing.

The role of the host-microbiome and metabolomics in sarcoidosis

Sarcoidosis is a complex inflammatory fibrotic disease that affects multiple organ systems. It is characterized by the infiltration of lymphocytes and mononuclear phagocytes, which form non-caseating granulomas in affected organs. The lungs and intrathoracic lymph nodes are the most commonly affected organs. The underlying cause of sarcoidosis is unknown, but it is believed to occur in genetically predisposed individuals who are exposed to pathogenic organisms, environmental contaminants, or self and non-self-antigens. Recent research has suggested that the microbiome may play a role in the development of respiratory conditions, including sarcoidosis. Additionally, metabolomic studies have identified potential biomarkers for monitoring sarcoidosis progression. This review will focus on recent microbiome and metabolomic findings in sarcoidosis, with the goal of shedding light on the pathogenesis and possible diagnostic and therapeutic approaches.

Potential Association of Cutibacterium acnes with Sarcoidosis as an Endogenous Hypersensitivity Infection

The immunohistochemical detection of Cutibacterium acnes in sarcoid granulomas suggests its potential role in granuloma formation. C. acnes is the sole microorganism ever isolated from sarcoid lesions. Histopathologic analysis of some sarcoid lymph nodes reveals latent infection and intracellular proliferation of cell-wall-deficient C. acnes followed by insoluble immune-complex formation. Activation of T helper type 1 (Th1) immune responses by C. acnes is generally higher in sarcoidosis patients than in healthy individuals. Pulmonary granulomatosis caused by an experimental adjuvant-induced allergic immune response to C. acnes is preventable by antimicrobials, suggesting that the allergic reaction targets C. acnes commensal in the lungs. C. acnes is the most common bacterium detected intracellularly in human peripheral lungs and mediastinal lymph nodes. Some sarcoidosis patients have increased amounts of C. acnes-derived circulating immune complexes, which suggests the proliferation of C. acnes in affected organs. In predisposed individuals with hypersensitive Th1 immune responses to C. acnes, granulomas may form to confine the intracellular proliferation of latent C. acnes triggered by certain host-related or drug-induced conditions. Current clinical trials in patients with cardiac sarcoidosis are evaluating combined treatment with steroids and antimicrobials during active disease with continued antimicrobial therapy while tapering off steroids after the disease subsides.

Diagnosis and Treatment of Cardiac Sarcoidosis

About 5% of sarcoidosis patients develop clinically manifest cardiac features. Cardiac sarcoidosis (CS) typically presents with conduction abnormalities, ventricular arrhythmias and heart failure. Its diagnosis is challenging and requires a substantial degree of clinical suspicion as well as expertise in advanced cardiac imaging. Adverse events, particularly malignant arrhythmias and development of heart failure, are common among CS patients. A timely diagnosis is paramount to ameliorating outcomes for these patients. Despite weak evidence, immunosuppression (primarily with corticosteroids) is generally recommended in the presence of active inflammation in the myocardium. The burden of malignant arrhythmias remains important regardless of treatment, thus leading to the recommended use of an implantable cardioverter defibrillator in most patients with clinically manifest CS.

Sarcoidosis: Updates on therapeutic drug trials and novel treatment approaches

Sarcoidosis is a systemic granulomatous inflammatory disease of unknown etiology. It affects the lungs in over 90% of patients yet extra-pulmonary and multi-organ involvement is common. Spontaneous remission of disease occurs commonly, nonetheless, over 50% of patients will require treatment and up to 30% of patients will develop a chronic progressive non-remitting disease with marked pulmonary fibrosis leading to significant morbidity and death. Guidelines outlining an immunosuppressive treatment approach to sarcoidosis were recently published, however, the strength of evidence behind many of the guideline recommended drugs is weak. None of the drugs currently used for the treatment of sarcoidosis have been rigorously studied and prescription of these drugs is often based on off-label” indications informed by experience with other diseases. Indeed, only two medications [prednisone and repository corticotropin (RCI) injection] currently used in the treatment of sarcoidosis are approved by the United States Food and Drug Administration. This situation results in significant reimbursement challenges especially for the more advanced (and often more effective) drugs that are favored for severe and refractory forms of disease causing an over-reliance on corticosteroids known to be associated with significant dose and duration dependent toxicities. This past decade has seen a renewed interest in developing new drugs and exploring novel therapeutic pathways for the treatment of sarcoidosis. Several of these trials are active randomized controlled trials (RCTs) designed to recruit relatively large numbers of patients with a goal to determine the safety, efficacy, and tolerability of these new molecules and therapeutic approaches. While it is an exciting time, it is also necessary to exercise caution. Resources including research dollars and most importantly, patient populations available for trials are limited and thus necessitate that several of the challenges facing drug trials and drug development in sarcoidosis are addressed. This will ensure that currently available resources are judiciously utilized. Our paper reviews the ongoing and anticipated drug trials in sarcoidosis and addresses the challenges facing these and future trials. We also review several recently completed trials and draw lessons that should be applied in future.

The Role of Cutibacterium acnes in Sarcoidosis: From Antigen to Treatable Trait?

Cutibacterium acnes (C. acnes, formerly Propionibacterium acnes) is considered to be a non-pathogenic resident of the human skin, as well as mucosal surfaces. However, it also has been demonstrated that C. acnes plays a pathogenic role in diseases such as acne vulgaris or implant infections after orthopedic surgery. Besides a role in infectious disease, this bacterium also seems to harbor immunomodulatory effects demonstrated by studies using C. acnes to enhance anti-tumor activity in various cancers or vaccination response. Sarcoidosis is a systemic inflammatory disorder of unknown causes. Cultures of C. acnes in biopsy samples of sarcoidosis patients, its presence in BAL fluid, tissue samples as well as antibodies against this bacterium found in serum of patients with sarcoidosis suggest an etiological role in this disease. In this review we address the antigenic as well as immunomodulatory potential of C. acnes with a focus on sarcoidosis. Furthermore, a potential role for antibiotic treatment in patients with sarcoidosis will be explored.

The Evolving Landscape of Cutaneous Sarcoidosis: Pathogenic Insight, Clinical Challenges, and New Frontiers in Therapy

Sarcoidosis is a multisystem disorder of unknown etiology characterized by accumulation of granulomas in affected tissue. Cutaneous manifestations are among the most common extrapulmonary manifestations in sarcoidosis and can lead to disfiguring disease requiring chronic therapy. In many patients, skin disease may be the first recognized manifestation of sarcoidosis, necessitating a thorough evaluation for systemic involvement. Although the precise etiology of sarcoidosis and the pathogenic mechanisms leading to granuloma formation, persistence, or resolution remain unclear, recent research has led to significant advances in our understanding of this disease. This article reviews recent advances in epidemiology, sarcoidosis clinical assessment with a focus on the dermatologist's role, disease pathogenesis, and new therapies in use and under investigation for cutaneous and systemic sarcoidosis.

Potential therapeutic targets to prevent organ damage in chronic pulmonary sarcoidosis

INTRODUCTION

Sarcoidosis is a granulomatous inflammatory disease with high chances of reduced quality of life, irreversible organ damage, and reduced life expectancy when vital organs are involved. Any organ system can be affected, and the lungs are most often affected. There is no preventive strategy as the exact etiology is unknown, and complex immunogenetic and environmental factors determine disease susceptibility and phenotype. Present-day treatment options originated from clinical practice and are effective in many patients. However, a substantial percentage of patients suffer from unacceptable side effects or still develop refractory, threatening pulmonary or extrapulmonary disease.

AREAS COVERED

As non-caseating granulomas, the pathological hallmark of disease, are assigned to divergent activation and regulation of the immune system, targets in relation to the possible triggers of granuloma formation and their sequelae were searched and reviewed.

EXPERT OPINION

:The immunopathogenesis underlying sarcoidosis has been a dynamic field of study. Several recent new insights give way to promising new therapeutic targets, such as certain antigenic triggers (e.g. from Aspergillus nidulans), mTOR, JAK-STAT and PPARγ pathways, the NRP2 receptor and MMP-12, which await further exploration. Clinical and trigger related phenotyping, and molecular endotyping in sarcoidosis will likely hold the key for precision medicine in the future.

Propionibacterium acnes-Derived Circulating Immune Complexes in Sarcoidosis Patients

Propionibacterium acnes is a potential etiologic agent of sarcoidosis and a dysregulated immune response to the commensal bacterium is suspected to cause granuloma formation. P. acnes-derived insoluble immune complexes were recently demonstrated in sinus macrophages of sarcoidosis lymph nodes, suggesting local proliferation of the bacterium in affected organs. In the present study, we developed a method for detecting P. acnes-derived immune complexes in human blood by measuring the concentration of P. acnes-specific lipoteichoic acid (PLTA) detectable after an antigen retrieval pretreatment of plasma samples. Before pretreatment, anti-PLTA antibody was detected and PLTA could not be detected, in all plasma samples from 51 sarcoidosis patients and 35 healthy volunteers. After pretreatment, however, a significant level of PLTA (>105 ng/mL) was detected in 33 (65%) sarcoidosis patients and 5 (14%) control subjects, with 86% specificity and 65% sensitivity for sarcoidosis. In both groups, plasma anti-PLTA antibody titers did not differ between samples with and without detection of PLTA. PLTA levels were abnormally increased (>202 ng/mL) in 21 (41%) sarcoidosis patients. These findings suggest that P. acnes-derived circulating immune complexes present in human blood are abnormally increased in many sarcoidosis patients, presumably due to local proliferation of the bacterium in the affected organs.

Non-steroidal treatment of cardiac sarcoidosis: A systematic review

The treatment of active cardiac sarcoidosis (CS) usually involves immunosuppressive therapy, with the goal of preventing inflammation-induced scar formation. In most cases, steroids remain the first-line treatment for CS. However, given the side effect profile of their long-term use, steroid-sparing therapies are increasingly used. There are no published randomized trials of steroid-sparing agents in CS. We sought to do a systematic review to evaluate the current published data on the use of non-steroidal treatments in the management of CS. We searched the Cochrane Library, Ovid Medline, Ovid Embase, PubMed, and Web of Science Core Collection databases from inception of database to August 2020 to identify the effectiveness of biological or synthetic disease-modifying antirheumatic agents (s- and bDMARDs). Secondary objectives include safety profile as well as the change in the average corticosteroid dose after treatment initiation. Twenty-three studies were ultimately selected for inclusion which included a total of 480 cases of CS treated with a range of both s- and bDMARDs. In all included studies, sDMARDs and bDMARDs were studied in combination with steroids or as second or higher-line treatments after therapeutic failure or intolerance to corticosteroid use. Methotrexate (MTX) and infliximab (IFX) were the most common synthetic and biologic DMARDs studied respectively, reported in about 35% of the studies reviewed. The use of steroid-sparing agents was associated with a reduction in the maintenance steroid dose used. In conclusion, steroids will remain as the cornerstone of anti-inflammatory management in patients with CS until trials on the use and safety profile of other immunosuppressive agents are completed and published.

Presence of Propionibacterium acnes in granulomas associates with a chronic disease course in Dutch sarcoidosis patients

Several studies demonstrated that Propionibacterium acnes may be involved in sarcoidosis pathogenesis. Presence of P. acnes was found in granulomas of the majority of Japanese sarcoidosis patients. However, presence of P. acnes in tissue has never been related to sarcoidosis phenotypes and clinical outcome. Therefore, the aims of our study were to demonstrate whether P. acnes can be detected in granulomas of Dutch sarcoidosis patients and to investigate whether its presence is related to a clinical phenotype and/or course of disease.

Sections of formalin-fixed paraffin-embedded tissue blocks of 76 sarcoidosis patients were examined by immunostaining with a P. acnes-specific monoclonal antibody (PAB antibody) using a Ventana BenchMark ULTRA. Clinical outcome status (COS) was determined and classified into two phenotype groups: A: resolved, minimal or persistent disease without treatment (COS 1–6) and B: persistent disease with need for treatment (COS 7–9).

P. acnes was detected in samples of 31 patients (41%) and located within granulomas in samples of 13 patients (17%). The frequency of P. acnes detected in granulomas at diagnosis was significantly higher in patients with phenotype B compared to patients with phenotype A (29% versus 0%, p=0.021).

Presence of P. acnes in granulomas can be confirmed in Dutch sarcoidosis patients. It is intriguing that presence of P. acnes in granulomas is more frequently found in patients with chronic disease requiring treatment. This adds to the rationale that a subgroup of sarcoidosis patients might benefit from antibiotic therapy.

Significantly more sarcoidosis patients with a chronic disease course requiring treatment have presence of P. acnes in granulomas. This contributes to the premise that it is relevant to further explore antibacterial therapy in sarcoidosis.https://bit.ly/36wCbbw

Host-microbe interactions in the pathogenesis and clinical course of sarcoidosis

Sarcoidosis is a rare inflammatory disease characterized by the development of granulomas in various organs, especially in the lungs and lymph nodes. Clinics of the disease largely depends on the organ involved and may range from mild symptoms to life threatening manifestations. Over the last two decades, significant advances in the diagnosis, clinical assessment and treatment of sarcoidosis have been achieved, however, the precise etiology of this disease remains unknown. Current evidence suggests that, in genetically predisposed individuals, an excessive immune response to unknown antigen/s is crucial for the development of sarcoidosis. Epidemiological and microbiological studies suggest that, at least in a fraction of patients, microbes or their products may trigger the immune response leading to sarcoid granuloma formation. In this article, we discuss the scientific evidence on the interaction of microbes with immune cells that may be implicated in the immunopathogenesis of sarcoidosis, and highlight recent studies exploring potential implications of human microbiota in the pathogenesis and the clinical course of sarcoidosis.