Anti-Ro/SSA antibodies and cardiac rhythm disturbances: Present and future perspectives

Anti-Ro and anti-La seropositivity is associated with increased rates of ischemic heart disease in adults: Results from a large population-based study

BACKGROUND AND AIMS

Emerging evidence suggests an arrhythmogenic effect of Anti-Ro/SSA (anti-Ro) and anti-La/SSB (anti-La) antibodies in adults, potentially involving a subclinical intracardiac inflammatory process. Despite the established association between inflammation and ischemic heart disease (IHD), it is noteworthy that as of now no study has delved into the potential link between these antibodies and IHD. This population-based study aimed to examine the association between anti-Ro/La seropositivity and IHD in the general adult population.

METHODS

We conducted a retrospective study using electronic medical records from the largest health maintenance organization in Israel. Patients with positive serology for either or both anti-Ro and anti-La antibodies were included, along with matched controls. Multivariate logistic regression models were utilized to assess the odds of IHD in seropositive patients compared to controls.

RESULTS

Among 17,231 seropositive patients and 84,368 controls, the rate of IHD was significantly higher in the seropositive group (9.7 % vs. 8.1 %,OR = 1.23; 95%CI 1.14-1.31; p<0.001). The association was more pronounced in younger patients [<40 years old (OR = 3.36; 95%CI 1.66-6.82; p<0.001), 40-49 years old (OR = 1.85; 95%CI 1.26-2.73; p<0.01), 50-59 years old (OR = 1.87; 95%CI 1.55-2.26; p<0.001), 60-69 years old (OR = 1.26; 95%CI 1.11-1.42; p<0.001), ≥70 years old (OR = 1.11; 95%CI 1.03-1.20; p<0.01)], as well as in patients with fewer traditional cardiovascular risk-factors (none:OR = 1.29; 95 % CI 1.09 to 1.77; p<0.01, 1-2:OR = 1.30; 95 % CI 1.19 to 1.41; p<0.001, ≥3:OR = 1.09; 95 % CI 0.99 to 1.21; p=0.076).

CONCLUSIONS

Our study demonstrates for the first time a positive association between anti-Ro/La seropositivity and IHD in the general adult population, especially among younger individuals with fewer traditional cardiovascular risk factors.

Experience of treating congenital complete atrioventricular block with epicardial pacemaker in infants and young children: a retrospective study

BACKGROUND

This article summarizes the treatment experience for congenital complete atrioventricular block (CCAVB) in newborns and infants, and discusses the necessity and feasibility of treating CCAVB with permanent pacemaker implantation in this population.

METHODS

In this study, the clinical data and follow-up results of nine children admitted at our center with CCAVB from January 2005 to March 2023 were retrospectively analyzed. Among them, two children received early implantation of permanent pacemakers (within 1 year of age), two children received non-early implantation (1 year or older), and the remaining five children received no pacemaker implantation. CCAVB diagnosis was confirmed by clinical symptoms and clinical examinations, including electrocardiography and echocardiography before surgery. After surgery, the pacing and sensing functions of the pacemaker were observed using electrocardiography, echocardiography, and pacing threshold monitoring. A comprehensive assessment of the treatment efficacy was conducted, encompassing improvements in clinical symptoms, growth and development, as well as the absence of any additional potential complications. The children who did not receive pacemaker implantation were followed up.

RESULTS

Among the four children who successfully received pacemaker implantation, one child who received non-early implantation died. For the remaining three children, the threshold level, amplitude, impedance, and minute ventilation sensor function of the pacemaker were good during the follow-up period, with a heart rate at the pacing rate. The growth and development of the aforementioned patients who received pacemaker implantation demonstrated adherence to the percentile curve, and their motor and cognitive development remained unaffected. However, among the children who did not undergo pacemaker implantation, two experienced death, while three were lost to follow-up, thereby limiting the evaluation of their long-term outcomes.

CONCLUSIONS

Early implantation of an epicardial pacemaker at an early stage in newborns and infants diagnosed with CCAVB can significantly improve clinical symptoms without affecting their growth and development. These data are in line with current literature and suggest that early implantation of an epicardial pacemaker in newborns and infants diagnosed with CCAVB but further studies are needed.

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

BACKGROUND

In ∼50% of severe atrioventricular blocks (AVBs) occurring in adults <50 years, the underlying etiology remains unknown. Preliminary evidence from case reports suggests that autoimmunity, specifically the presence of circulating anti-Ro/SSA antibodies in the patient (acquired form), in the patient's mother (late-progressive congenital form), or in both (mixed form), could be involved in a fraction of idiopathic AVBs in adults by possibly targeting the L-type calcium channel (Cav1.2) and inhibiting the related current (ICaL).

OBJECTIVES

The purpose of this study was to evaluate whether anti-Ro/SSA antibodies are causally implicated in the development of isolated AVBs in adults.

METHODS

Thirty-four consecutive patients with isolated AVB of unknown origin and 17 available mothers were prospectively enrolled in a cross-sectional study. Anti-Ro/SSA antibodies were assessed by fluoroenzyme-immunoassay, immuno-Western blotting, and line-blot immunoassay. Purified immunoglobulin-G (IgG) from anti-Ro/SSA-positive and anti-Ro/SSA-negative subjects were tested on ICaL and Cav1.2 expression using tSA201 and HEK293 cells, respectively. Moreover, in 13 AVB patients, the impact of a short course of steroid therapy on AV conduction was evaluated.

RESULTS

Anti-Ro/SSA antibodies, particularly anti-Ro/SSA-52kD, were found in 53% of AVB-patients and/or in their mothers, most commonly an acquired or mixed form (two-thirds of cases) without history of autoimmune diseases. Purified IgG from anti-Ro/SSA-positive but not anti-Ro/SSA-negative AVB patients acutely inhibited ICaL and chronically down-regulated Cav1.2 expression. Moreover, anti-Ro/SSA-positive sera showed high reactivity with peptides corresponding to the Cav1.2 channel pore-forming region. Finally, steroid therapy rapidly improved AV conduction in AVB-patients with circulating anti-Ro/SSA antibodies but not in those without.

CONCLUSIONS

Our study points to anti-Ro/SSA antibodies as a novel, epidemiologically relevant and potentially reversible cause of isolated AVB in adults, via an autoimmune-mediated functional interference with the L-type calcium channels. These findings have significant impact on antiarrhythmic therapies by avoiding or delaying pacemaker implantation.

Association of anti-Ro seropositivity with cardiac rhythm and conduction disturbances

AIMS

Anti-Ro/La autoantibodies are especially prevalent in autoimmune diseases but are also relatively frequent in healthy adults. Their arrhythmogenic effect on the immature cardiac conductive system is well established, with substantial evidence demonstrating an increased risk for congenital atrioventricular block in neonates of seropositive mothers. Despite their wide distribution and their arrhythmogenic potential effect, there are no large population studies conducted in seropositive adults. Thus, this is the first large population-based study to examine the association of anti-Ro/La seropositivity with cardiac rhythm and conduction disturbances.

METHODS AND RESULTS

This cross-sectional designed study involved the electronic health records of the largest health maintenance organization in Israel. All subjects that were tested positive for anti-Ro/anti-La antibodies between the years 2002 and 2019 were included and were matched by age, gender, and place of residence, with controls. Rates of different cardiac rhythm and conduction disturbances were compared between groups. Sensitivity analyses were performed using propensity score matching. The study population included 17 231 anti-Ro/La seropositive subjects and 84 368 controls. Anti-Ro seropositive patients had higher rates of conduction disturbances (3.0 vs. 1.7%, P < 0.001) and rhythm disturbances (10.5 vs. 7.0%, P < 0.001). Patients who tested positive for anti-La alone did not demonstrate a significant association with arrhythmias. Multivariate logistic regression analysis, controlling for possible confounders, showed an increased risk for cardiac conduction disturbances [odds ratio (OR) 1.44, 95% confidence interval (CI) 1.25-1.66, P < 0.001], as well as for cardiac rhythm disturbances (OR 1.21, 95% CI 1.11-1.31, P < 0.001) among anti-Ro seropositive patients. However, the association with rhythm disturbances was more robust in certain subgroup analyses.

CONCLUSIONS

Anti-Ro seropositivity is positively associated with adult cardiac conduction disturbances and, to a lesser extent, cardiac rhythm disturbances, regardless of the presence of concurrent autoimmune disease.

Systemic lupus erythematosus increases risk of incident atrial fibrillation: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Patients with systemic lupus erythematosus (SLE) might have increased risk of atrial fibrillation (AF) as a result of initiating chronic and systematic inflammation. However, the prevalence of AF in patients with SLE have not been well quantified. The aim of this systematic review and meta-analysis was to collect and identify available clinical data to explore this possible correlation.

METHODS

Articles were searched based on electronic databases (PubMed, Scopus, ScienceDirect, Cochrane Library, Web of Science). Review Manager 5.4 was used to perform meta-analysis of all selected studies and subgroup analyses (pooled separately by geographical distribution). Pooled risk ratio (RR) and 95% confidence intervals (95% CI) were calculated by random-effect model or fix-effect model.

RESULTS

Six cohort studies were involved in this meta-analysis, including 311 844 participants, 78 134 cases of SLE and 347 883 non-SLE controls. Pooled studies indicated increased risk of AF development in patients with SLE compared to participants without SLE (I²  = 96%, RR = 1.85; 95% CI: 1.23-2.79; P = .003). Four clinical trials including only European/ American populations were analyzed in subgroups. Heterogeneity analysis showed that I²  = 9% and there was an increase in the risk of AF development in European/ American patients with SLE (RR = 1.79; 95% CI: 1.61-1.98; P < .001), while in 2 Korean studies, the heterogeneity was 98% and there was no correlation between AF and SLE (RR = 1.81, 95% CI: 0.39-8.43). Five clinical studies were involved in subgroup analysis after excluding the Beak study, with I²  = 96% and they suggested that SLE increased the risk of AF development (RR = 2.13, 95% CI: 1.42-3.21, P = .002).

CONCLUSION

This meta-analysis suggested that SLE may be a risk factor for AF development and the results may vary with geographic distribution.

Unusual course of congenital complete heart block in an adult: A case report

BACKGROUND

Congenital complete heart block (CCHB) with normal cardiac structure and negativity for anti-Ro/La antibody is rare. Additionally, CCHB is much less frequently diagnosed in adults, and its natural history in adults is less well known.

CASE SUMMARY

A 23-year-old woman was admitted to our hospital for frequent syncopal episodes. She had bradycardia at the age of 1 year but had never had impaired exercise capacity or a syncopal episode before admission. The possible diagnosis of acquired complete atrioventricular block was carefully ruled out, and then the diagnosis of CCHB was made. According to existing guidelines, permanent pacemaker implantation was recommended, but the patient declined. With regular follow-up for 28 years, the patient had an unusually good outcome without any invasive intervention or medicine. She had an uneventful pregnancy and led a normally active life without any symptoms of low cardiac output or syncopal recurrence.

CONCLUSION

This case implies that CCHB in adulthood may have good clinical outcomes and does not always require permanent pacemaker implantation.

Usefulness of cardiac screening in patients with systemic lupus erythematosus and anti-Ro/SSA antibodies

OBJECTIVES

Recent data suggest that some adult patients with autoimmune rheumatic diseases may develop cardiac conduction and repolarization abnormalities mediated by anti-Ro/SSA antibodies. We aim to investigate the utility of a cardiac screening in patients with systemic lupus erythematous (SLE) and anti-Ro/SSA positivity.

METHODS

SLE patients who consecutively attended a Rheumatology clinic during 1 year where evaluated for the presence and levels of anti-Ro/SSA antibodies, and clinical and biological markers of organ damage and disease activity. All participants underwent a cardiovascular anamnesis and physical examination, ECG, echocardiography, and 24-hour Holter.

RESULTS

Of the 145 recruited patients, 49 (32%) had anti-Ro/SSA positivity. None had any degree of atrioventricular block in the ECG or Holter monitoring. No significant differences were observed between anti-Ro/SSA-positive vs. negative patients in terms of PR, QRS or QTc intervals. No clinically significant arrhythmias were recorded during Holter monitoring and no differences in average heart rate, heart rate variability, or atrial or ventricular ectopy burden were observed. Finally, no differences were found in echocardiographic measurements.

CONCLUSIONS

In this study of SLE patients, anti-Ro/SSA positivity was not associated with significant alterations in ECG, echocardiography, or 24-hour Holter. These findings do not support ordinary cardiac evaluation in these patients. (Clinicaltrials.gov registration number: NCT02162992).

Outcomes of atrial fibrillation hospitalizations in patients with systemic lupus erythematosus: a report from the national inpatient sample

This study compares outcomes of patients admitted for atrial fibrillation (AF) with and without coexisting systemic lupus erythematosus (SLE). The primary outcome was inpatient mortality. Hospital length of stay (LOS), total hospital charges, odds of undergoing ablation, pharmacologic cardioversion and electrical cardioversion were secondary outcomes of interest. Data were abstracted from the National Inpatient Sample (NIS) 2016 and 2017 database. The NIS was searched for adult hospitalizations with AF as principal diagnosis with and without SLE as secondary diagnosis using International Classification of Diseases, Tenth Revision, Clinical Modification codes. Multivariate logistic and linear regression analysis was used accordingly to adjust for confounders. There were over 71 million discharges included in the combined 2016 and 2017 NIS database. 821,630 hospitalizations were for adult patients, who had a principal diagnosis of AF, out of which, 2645 (0.3%) had SLE as secondary diagnosis. Hospitalizations for AF with SLE had similar inpatient mortality (1.5% vs 0.91%, adjusted OR (AOR): 1.0, 95% CI 0.47 to 2.14, p=0.991), LOS (4.2 vs 3.4 days, p=0.525), total hospital charges ($51,351 vs $39,121, p=0.056), odds of undergoing pharmacologic cardioversion (0.38% vs 0.38%, AOR: 0.90, 95% CI 0.22 to 3.69, p=0.880) and electrical cardioversion (12.9% vs 17.5%, AOR 0.87, 95% CI 0.66 to 1.15, p=0.324) compared with those without SLE. However, SLE group had increased odds of undergoing ablation (6.8% vs 4.2%, AOR: 1.9, 95% CI 1.3 to 2.7, p<0.0001). Patients admitted for AF with SLE had similar inpatient mortality, LOS, total hospital charges, likelihood of undergoing pharmacologic and electrical cardioversion compared with those without SLE. However, SLE group had greater odds of undergoing ablation.

Cardiac Arrhythmias in Autoimmune Diseases

Autoimmune diseases (ADs) affect approximately 10% of the world's population. Because ADs are frequently systemic disorders, cardiac involvement is common. In this review we focus on typical arrhythmias and their pathogenesis, arrhythmia-associated mortality, and possible treatment options among selected ADs (sarcoidosis, systemic lupus erythematosus, scleroderma, type 1 diabetes, Graves' disease, rheumatoid arthritis, ankylosing spondylitis [AS], psoriasis, celiac disease [CD], and inflammatory bowel disease [IBD]). Rhythm disorders have different underlying pathophysiologies; myocardial inflammation and fibrosis seem to be the most important factors. Inflammatory processes and oxidative stress lead to cardiomyocyte necrosis, with subsequent electrical and structural remodeling. Furthermore, chronic inflammation is the pathophysiological basis linking AD to autonomic dysfunction, including sympathetic overactivation and a decline in parasympathetic function. Autoantibody-mediated inhibitory effects of cellular events (i.e., potassium or L-type calcium currents, M₂muscarinic cholinergic or β₁-adrenergic receptor signaling) can also lead to cardiac arrhythmia. Drug-induced arrhythmias, caused, for example, by corticosteroids, methotrexate, chloroquine, are also observed among AD patients. The most common arrhythmia in most AD presentations is atrial arrhythmia (primarily atrial fibrillation), expect for sarcoidosis and scleroderma, which are characterized by a higher burden of ventricular arrhythmia. Arrhythmia-associated mortality is highest among patients with sarcoidosis and lowest among those with AS; there are scant data related to mortality in patients with psoriasis, CD, and IBD.

Arrhythmia and/or Cardiomyopathy Related to Maternal Autoantibodies: Descriptive Analysis of a Series of 16 Cases From a Single Center

Objective: To describe the clinical characteristics of maternal autoantibody-mediated arrhythmia and/or cardiomyopathy, and to explore the therapeutic role of glucocorticoids in these diseases. Methods: This was a retrospective observational study of 2 fetuses and 14 children who presented with autoantibody-mediated arrhythmia and/or cardiomyopathy in our hospital from September 2010 to December 2018. Results: In total, 16 patients were identified, including 2 fetuses, and 14 children. One mother suffered from Sjogren's syndrome, two suffered from systemic lupus erythematosus (SLE), and the remaining 13 were asymptomatic carriers of autoantibodies. Two fetuses were diagnosed with complete congenital heart block (CHB) and had mean heart rates of 45 and 50 bpm. In the 14 surviving children, third-degree CHB was detected in 4 children, second- to third-degree CHB in 4, corrected QT interval (QTc) prolongation in 1, atrioventricular dissociation, and junctional ectopic tachycardia in 1, complete left bundle branch block (CLBBB) with dilated cardiomyopathy (DCM) in 3, and endocardial fibroelastosis (EFE) in 1. All of the 14 surviving babies received intravenous immunoglobulin and glucocorticoids. None of the children received pacemaker implantation. During the follow-up, one 3-month-old girl who had complete CHB, DCM, and Torsades de pointes almost recovered after the administration of prednisone for ~8 years. Three cases with complete CHB had no improvement after 3-5 years of follow-up. One case with EFE and three cases with CLBBB and DCM were in stable condition now. Children with QTc prolongation and junctional ectopic tachycardia returned to a regular rhythm. Conclusions: Autoantibody-mediated arrhythmias and/or cardiomyopathy are severe complications related to maternal autoantibodies, and the administration of steroid may be beneficial in reversing complete CHB.

Association of Anti-Ro/Sjögren's syndrome type A Antibodies and Complete Atrioventricular Block in an Adult With Sjögren's Syndrome

A 57-year-old female patient with underlying hypertension, dyslipidemia, membranous glomerulonephritis, and Sjögren's syndrome presented to our clinic with near-syncope and dizziness symptoms. We detected non-conducted sinus beat in 12-lead electrocardiography. An echocardiography showed that the left ventricular systolic function was preserved without a regional wall abnormality. The patient did not have symptoms of congestive heart failure or recent myocardial infarction. We observed complete atrioventricular block with longest pause of 6.2 seconds in a 24-hour Holter electrocardiography, and subsequently implanted a permanent pacemaker. Anti-Ro/Sjögren's syndrome type A antibodies are commonly seen in Sjögren's syndrome and associated with a neonatal complete heart block. The pathogenesis of anti-Ro/Sjögren's syndrome type A antibodies in the conduction system of an adult heart is still uncertain. In this article, we report Sjögren's syndrome in an adult patient with complete atrioventricular block and membranous glomerulonephritis, which may be associated with a positive titer of anti-Ro/Sjögren's syndrome type A antibodies.

Prolonged Tpeak-Tend interval in anti-Ro52 antibody-positive connective tissue diseases

Patients with connective tissue diseases (CTDs) may have prolonged corrected QT interval which indicates increased risk for ventricular arrhythmias. However, a more sensitive measure of ventricular repolarization, T-peak-to-end (Tpe) interval, has not been studied in CTDs. We aimed to investigate the relationship between ventricular repolarization abnormalities and anti-Ro52-positivity in subjects with connective tissue diseases (CTDs). We enrolled patients with anti-Ro52-positive CTDs, ANA-positive CTDs, and healthy subjects in this cross-sectional study. We excluded conditions potentially affecting the QT interval. We compared the ECG measures between the groups and performed analyses to define factors associated with ventricular repolarization measures. 15 ANA and anti-Ro52-positive, 39 ANA-positive and anti-Ro52-negative, and 22 healthy subjects were enrolled. None of the subjects had rhythm or conduction disturbances. Corrected QT intervals were similar between the groups. Tpe (84, 77.3, and 69.4 msn, respectively) and QT-dispersion (40, 27.2, and 20.1 msn, respectively) were higher in anti-Ro52-positive subjects compared with the ANA-positive and healthy subjects. Anti-Ro52 titers were correlated with Tpe and QT-dispersion (r = 0.52 and p < 0.001 for each). ANA and anti-Ro52-positivity were independently associated with higher Tpe (OR = 7.7, p = 0.001 and OR = 6.9, p = 0.001, respectively), corrected Tpe (OR = 11.3, p = 0.001 and OR = 8.4, p = 0.003, respectively), QT dispersion (OR = 7, p = 0.008 and OR = 13, p < 0.001, respectively), and QTc dispersion (OR = 9.1, p = 0.001 and OR = 14.1, p < 0.001, respectively). This study provides evidence that ANA positivity, especially when concomitant anti-Ro52-positivity is present, significantly deteriorates ventricular repolarization. The aforementioned ventricular repolarization abnormalities may render these subjects susceptible to serious rhythm or conduction disorders in the setting of predisposing conditions.

Long QT Syndrome: An Emerging Role for Inflammation and Immunity

The long QT syndrome (LQTS), classified as congenital or acquired, is a multi-factorial disorder of myocardial repolarization predisposing to life-threatening ventricular arrhythmias, particularly torsades de pointes. In the latest years, inflammation and immunity have been increasingly recognized as novel factors crucially involved in modulating ventricular repolarization. In the present paper, we critically review the available information on this topic, also analyzing putative mechanisms and potential interplays with the other etiologic factors, either acquired or inherited. Accumulating data indicate inflammatory activation as a potential cause of acquired LQTS. The putative underlying mechanisms are complex but essentially cytokine-mediated, including both direct actions on cardiomyocyte ion channels expression and function, and indirect effects resulting from an increased central nervous system sympathetic drive on the heart. Autoimmunity represents another recently arising cause of acquired LQTS. Indeed, increasing evidence demonstrates that autoantibodies may affect myocardial electric properties by directly cross-reacting with the cardiomyocyte and interfering with specific ion currents as a result of molecular mimicry mechanisms. Intriguingly, recent data suggest that inflammation and immunity may be also involved in modulating the clinical expression of congenital forms of LQTS, possibly triggering or enhancing electrical instability in patients who already are genetically predisposed to arrhythmias. In this view, targeting immuno-inflammatory pathways may in the future represent an attractive therapeutic approach in a number of LQTS patients, thus opening new exciting avenues in antiarrhythmic therapy.