Anti-Ro/SSA Antibodies Blocking Calcium Channels as a Potentially Reversible Cause of Atrioventricular Block in Adults

Anti-SSA/Ro antibody-positive autoimmune myocarditis combined with complete atrioventricular block requiring implantation with a permanent pacemaker: A case report

BACKGROUND

Autoimmune myocarditis (AM) associated with autoimmune diseases can cause complete atrioventricular block (CAVB), but the related autoantigens and the underlying mechanisms are unclear. Anti-SSA/Ro antibodies may play an important role in this process, but cases of AM with positive anti-SSA/Ro antibodies are rare. In addition, arrhythmias, such as atrioventricular block, are very common in patients with autoimmune diseases, but severe atrioventricular block requiring permanent pacemaker implantation is extremely rare.

CASE SUMMARY

The patient in this case had AM with anti-SSA/Ro antibody positivity, which was associated with connective tissue disease, and the patient subsequently developed CAVB. After intensive immunosuppressive therapy, the antibody test results became negative, and pulmonary hypertension significantly improved. However, the outcome of permanent pacemaker implantation did not change.

CONCLUSION

In clinical practice, the awareness of adult AM associated with autoimmune diseases combined with CAVB should be strengthened in clinicians, and anti-SSA/Ro antibodies may play a role in this process. Therefore, improving the detection of antibodies and early intervention, such as active immunosuppression therapy, may be very important for improving disease prognosis. For patients who do not respond to immunosuppressive therapy, implantation of a permanent pacemaker may become an essential treatment option.

Immune cells and arrhythmias

Cardiac arrhythmias are a significant cause of morbidity and mortality worldwide. Emerging evidence has demonstrated that resident and infiltrating cardiac immune cells play direct, mechanistic roles in arrhythmia onset and progression. In this review, we provide a comprehensive summary and expert commentary on the role of each immune cell subtype in the pathogenesis of atrial and ventricular arrhythmias.

Autoimmune cardiac channelopathies and heart rhythm disorders: A contemporary review

Cardiac arrhythmias still represent a major health problem worldwide, at least in part because the fundamental pathogenic mechanisms are not fully understood, thus affecting the efficacy of therapeutic measures. In fact, whereas cardiac arrhythmias are in most cases due to structural heart diseases, the underlying cause remains elusive in a significant number of patients despite intensive investigations even including postmortem examination and molecular autopsy. A large body of data progressively accumulated during the last decade provides strong evidence that autoimmune mechanisms may be involved in a significant number of such unexplained or poorly explained cardiac arrhythmias. Several proarrhythmic anti-cardiac ion channel autoantibodies have been discovered, in all cases able to directly interfere with the electrophysiologic properties of the heart but leading to different arrhythmic phenotypes, including long QT syndrome, short QT syndrome, and atrioventricular block. These autoantibodies, which may develop independent of a history of autoimmune diseases, could help explain a percentage of arrhythmic events of unknown origin, thereby opening new frontiers for diagnosis and treatment of heart rhythm disorders. Based on this evidence, the novel term autoimmune cardiac channelopathies was coined in 2017. Since then, the interest in the field of cardioimmunology has shown a tumultuous growth, so much so that the number of arrhythmogenic anti-ion channel autoantibodies reported has significantly increased, also in association with not previously described arrhythmic phenotypes, such as atrial fibrillation, Brugada syndrome, and ventricular fibrillation/cardiac arrest. Thus, an updated reassessment of this topic, also highlighting perspectives and unmet needs, has become necessary and represents the main objective of this review.

Treatment options for preventing autoimmune-mediated congenital heart block: a systematic review

OBJECTIVE

Complete congenital heart block (CHB) due to anti-Ro/La antibodies in pregnancy can lead to adverse fetal outcomes and neonatal death. National and international guidelines do not recommend specific treatment for women identified with anti-Ro antibodies while pregnant.

DESIGN

Systematic review of studies of pregnant women with anti-Ro/La antibodies undertaking treatment(s) to prevent CHB. Studies solely focused on treating developing or established CHB were excluded.

MAIN OUTCOME MEASURE

CHB incidence.

RESULTS

Of 1049 articles, 20 studies were eligible, of which 13 were retrospective. Sixteen studies contained usable data comparing various treatments (seven hydroxychloroquine (HCQ), six corticosteroids, two intravenous immunoglobulin (IVIG) and one each on combined HCQ and corticosteroids and plasmapheresis), including 2134 women and 2915 pregnancies. Meta-analysis was not possible due to heterogeneity. HCQ as primary prophylaxis showed protective effect on CHB incidence in four of five studies, whereas for preventing recurrence, only one study had a comparator arm, which showed a protective effect. Corticosteroids showed protective effect on CHB incidence as primary prophylaxis in two of three studies, whereas in recurrence, only one study showed protective effect. The IVIG study with a comparator showed no protective effect on CHB recurrence. Two studies (IVIG and plasmapheresis) had no comparator. The long-term toxicity of treatments was poorly investigated.

CONCLUSION

HCQ showed the most evidence among various treatment options to prevent CHB in babies of women with anti-Ro/La antibodies. However, included studies had high risk of bias and imprecision. Future studies should be prospective, compare existing treatments and capture adverse effects.PROSPERO registration number CRD42023492934.

Association between anti-SSA autoantibodies and conduction disturbances in heart failure

BACKGROUND

Conduction disturbances play an important role in the occurrence and development of heart failure (HF). Studies suggest autoantibodies may attack the conduction system. However, whether autoantibodies are associated with conduction disturbances in patients with HF is unclear.

OBJECTIVE

The purpose of this study was to assess whether anti-SSA, anti-Ro/Sjögren syndrome-related antigen A antibodies known for congenital atrioventricular block (AVB), is associated with conduction disturbances in patients with HF.

METHODS

This retrospective observational study used data from patients with HF who were admitted to Beijing Anzhen Hospital between January 2018 and June 2022. Patients who were tested for anti-SSA and had undergone electrocardiographic examination during hospitalization were included. Conduction disturbances, including AVB, bundle branch block (BBB), and intraventricular conduction delay, were confirmed by a cardiologist blinded to anti-SSA status. Univariate and multivariable logistic regression analyses were performed to assess the association between anti-SSA and conduction disturbances.

RESULTS

A total of 766 patients were included in this study, of whom 70 (9.1%) were anti-SSA positive. Subjects who were anti-SSA positive showed a higher prevalence of AVB (20% vs 10.6%) and BBB (27.3 % vs 10.9 %), including both left BBB and right BBB (all P <.05). After adjusting for known risk factors, anti-SSA was independently associated with AVB (odds ratio [OR] 2.42; 95% confidence interval [CI] 1.18-5.43; P = .03) and BBB (OR 3.15; 95% CI 1.68-5.89; P <.001).

CONCLUSION

Anti-SSA is independently associated with AVB and BBB in patients with HF. Further study of the role of autoantibodies in the development of conduction abnormalities in patients with HF to generate possible targeted treatments is required.

'Hot phase' non-dilated left ventricular cardiomyopathy with atypical onset and recurrence: a case report

Non-dilated left ventricular cardiomyopathy (NDLVC) is a newly categorized cardiomyopathy phenotype includingseveral aetiologies with a linking characteristic represented by the normal left ventricular volume. Inflammatory heart disease (InHD) is a heterogeneous process with variegate clinical manifestations, sometimes in overlap with NDLVC. A 26-year-old woman was admitted forcomplete heart block (CHB) and persistently raised troponin. Echocardiography and coronary angiography were normal. Extensive oedema and late gadolinium enhancement was found at cardiac magnetic resonance. Endomyocardial biopsy showed no signs of active myocarditis. Steroid therapy was started with restoration of atrioventricular conduction but subsequently the patient experienced a mild recurrence with a new troponin relapse. Genetic test was negative for mutations related with the clinical scenario. In this case of NDLVC with InHD the precise diagnostic work-up, including genetic test, was crucial for diagnostic, prognostic andtherapeutic purposes. Multimodality approach is crucial to detect and treat possible recurrences.

Relationship between clinical manifestations and serological profile in patients affected by Systemic Lupus Erythematosus

Background

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder characterized by a variety of both signs and symptoms; it mainly affects women of childbearing age, with an estimated prevalence of 24/100,000 people in Europe and North America. SLE is often described as an antibodies-driven disease as its clinical manifestations are usually associated with the presence or the absence of specific antibodies.

Objectives

To evaluate clinical manifestations in patients with SLE and to assess the relationship with the presence of specific antibodies by using real-world data.

Methods

A retrospective study was performed; the 2019 EULAR/ACR Classification Criteria for Systemic Lupus Erythematosus were used to classify patients with SLE. Data concerning serological profiles (which included Antinuclear antibodies - ANA, anti dsDNA, anti-Ro/SS-A, anti-La/SS-B, anti-Smith) were gathered along with medical records of clinical manifestations. Complement levels were also tested for possible clinical correlations. χ² or Fisher's exact tests were utilized to establish associations between autoantibodies and symptoms. The odds ratios (OR) and their 95% confidence intervals (CI) were computed. No correction was made for multiple testing; only a p-value 0.01 ≤ was considered significant.

Results

One-hundred and twenty-seven patients (n=127, mean age 53.43 ± 14.02) were enrolled in this study. Anti-dsDNA antibodies were found to be statistically significant for both malar rash and proteinuria; anti-Ro/SSA antibodies showed an association with photosensitivity and pericarditis; furthermore, a strong association was found between anti-Ro antibodies and proteinuria, but only if anti-dsDNA antibodies were present as well. Patients who tested positive for anti-La/SSB antibodies correlated with a threefold increase in the risk of developing pericarditis. Lastly, anti-Smith appeared to be associated with NPSLE as well as an increased risk for both autoimmune hemolytic anemia and thrombocytopenia.

Conclusions

In our study, many associations confirmed those found in previous studies; however, new relationships between antibodies and clinical manifestations were found thus indicating the need for additional evaluations to assess these correlations further.

Should Physicians Be Aware of Rhythm Disturbances in Adults with Systemic Autoimmune Diseases and Anti-Ro52 Antibodies? A Cross-Sectional Study

Objectives: The association between anti-Ro/SSA antibodies and the appearance of cardiac rhythm disorders in adults is discussed. We aim to study this relationship, together with active treatments and comorbidities, and its impact on daily clinical practice in adults with systemic autoimmune diseases (SADs). Methods: This cross-sectional single-center study was conducted in a tertiary hospital between January 2021 and March 2022. A sample of adult patients followed up in the SAD Unit with a diagnosis of a SAD and previously tested for anti-Ro/SSA and anti-La/SSB were recruited. All of them underwent a 12-lead electrocardiogram. Results: 167 patients were included. 90 (53.9%) were positive for anti-Ro60, 101 (60.5%) for anti-Ro52, and 45 (26.9%) for anti-La/SSB; 52 (31.3%) were triple-negative. 84% were women, and the mean age was 59 years (standard deviation 12.8). The most common SAD was primary Sjögren's syndrome (34.8%), followed by systemic lupus erythematosus (24.6%) and rheumatoid arthritis (22.8%). A statistically significant relationship was found between anti-Ro52 positivity and cardiac rhythm disorders (relative risk = 2.007 [1.197-3.366]), specifically QTc prolongation (relative risk = 4.248 [1.553-11.615]). Multivariate regressions showed a significant association, with diabetes mellitus being the most related comorbidity. The association between anti-Ro52 antibodies and atrioventricular conduction disorders was not significant. Conclusions: The presence of anti-Ro52 antibodies in adult patients with SADs is associated with an increased risk of QTc prolongation. Electrocardiographic screening of patients with SAD, anti-Ro52 antibodies, and other risk factors, like diabetes mellitus or QT-prolonging drugs, seems advisable. Those with baseline electrocardiogram abnormalities or additional risk factors should undergo electrocardiographic monitoring.

Cardiac conduction diseases: understanding the molecular mechanisms to uncover targets for future treatments

INTRODUCTION

The cardiac conduction system (CCS) is crucial for maintaining adequate cardiac frequency at rest and modulation during exercise. Furthermore, the atrioventricular node and His-Purkinje system are essential for maintaining atrioventricular and interventricular synchrony and consequently maintaining an adequate cardiac output.

AREAS COVERED

In this review article, we examine the anatomy, physiology, and pathophysiology of the CCS. We then discuss in detail the most common genetic mutations and the molecular mechanisms of cardiac conduction disease (CCD) and provide our perspectives on future research and therapeutic opportunities in this field.

EXPERT OPINION

Significant advancement has been made in understanding the molecular mechanisms of CCD, including the recognition of the heterogeneous signaling at the subcellular levels of sinoatrial node, the involvement of inflammatory and autoimmune mechanisms, and the potential impact of epigenetic regulations on CCD. However, the current treatment of CCD manifested as bradycardia still relies primarily on cardiovascular implantable electronic devices (CIEDs). On the other hand, an If specific inhibitor was developed to treat inappropriate sinus tachycardia and sinus tachycardia in heart failure patients with reduced ejection fraction. More work is needed to translate current knowledge into pharmacologic or genetic interventions for the management of CCDs.

Autoimmune congenital heart block: a case report and review of the literature related to pathogenesis and pregnancy management

Autoimmune congenital heart block (ACHB) is a passively acquired immune-mediated disease characterized by the presence of maternal antibodies against components of the Ro/SSA and La/SSB ribonucleoprotein complex that mainly affects the cardiac conducting system. ACHB occurs in 2% of women with positive anti-Ro/SSA and anti-La/SSB antibodies and causes a high risk of intrauterine fetal death, neonatal mortality, and long-term sequelae. In this review, we first describe a case of ACHB to provide preliminary knowledge. Then, we discuss the possible pathogenic mechanisms of ACHB; summarize the pregnancy management of patients with positive anti-Ro/SSA and anti-La/SSB antibodies and/or rheumatic diseases, the prevention of ACHB, and the treatment of ACHB fetuses; and propose routine screening of these antibodies for the general population. Careful follow-up, which consists of monitoring the fetal heart rate, is feasible and reassuring for pregnant women with positive anti-Ro/SSA and/or anti-La/SSB antibodies to lower the risk of ACHB in fetuses. Moreover, maternal administration of hydroxychloroquine may be useful in preventing ACHB in pregnant women with anti-Ro/SSA and/or anti-La/SSB antibodies.