Anti-Ro/SSA Antibodies and the Autoimmune Long-QT Syndrome

Advanced Atrioventricular Block in Athletes: Prevalence and Role of Anti-Ro/Sjögren Syndrome-Related Antigen A Antibodies

BACKGROUND

Advanced atrioventricular block (AVB), that is, higher than second-degree Mobitz-1, is an abnormal finding in athletes. Despite intensive investigation, in several cases the pathogenesis remains unknown, but frequently pacemaker implantation is still indicated. Increasing evidence points to circulating anti-Ro/Sjögren syndrome-related antigen A (SSA) antibodies cross-reacting with L-type calcium channel and inhibiting the related current as an epidemiologically relevant and potentially reversible cause of isolated AVB in adults. The aim of the study was to determine the prevalence of anti-Ro/SSA-associated advanced AVBs in a large sample of young athletes.

METHODS AND RESULTS

A total of 2536 consecutive athletes aged <40 years without a history of cardiac diseases/interventions were enrolled in a cross-sectional study. Resting and exercise electrocardiography was performed, and those presenting any AVB were further evaluated by 24-hour Holter ECG. Athletes with second-degree AVBs and their mothers underwent anti-Ro/SSA testing. Moreover, purified immunoglobulin G from subjects with anti-Ro/SSA-positive and anti-Ro/SSA-negative advanced AVB were tested on L-type calcium current and L-type-calcium channel expression using tSA201 cells. The global prevalence of advanced AVB in the overall sample was ≈0.1%, but the risk considerably increased (2%) when intensely trained postpubertal male subjects were selectively considered. While none of the athletes with advanced AVB showed heart abnormalities, in 100% of cases anti-Ro/SSA antibodies were detected. Ex vivo experiments showed that immunoglobulin G from anti-Ro/SSA-positive but not -negative subjects with advanced AVB acutely inhibit L-type calcium current and chronically downregulate L-type-calcium channel expression.

CONCLUSIONS

Our study provides evidence that advanced AVB occurs in young athletes, in most cases associated with anti-Ro/SSA antibodies blocking L-type calcium channels. These findings may open new avenues for immunomodulating therapies to reduce the risk of life-threatening events in athletes, avoiding or delaying pacemaker implantation.

Case report: A 56-year-old woman presenting with torsades de pointes and cardiac arrest associated with levosimendan administration and underlying congenital long QT syndrome type 1

Torsades de Pointes (TdP) is a malignant polymorphic ventricular tachycardia with heart rate corrected QT interval (QTc) prolongation, which may be attributed to congenital and acquired factors. Although various acquired factors for TdP have been summarized, levosimendan administration in complex postoperative settings is relatively uncommon. Timely identification of potential causes and appropriate management may improve the outcome. Herein, we describe the postoperative case of a 56-year-old female with initial normal QTc who accepted the administration of levosimendan for heart failure, suffered TdP, cardiac arrest, and possible Takotsubo cardiomyopathy, further genetically confirmed as long QT syndrome type 1 (LQT1). The patient was successfully treated with magnesium sulfate, atenolol, and implantable cardioverter defibrillator implantation. There should be a careful evaluation of the at-risk populations and close monitoring of the electrocardiograms, particularly the QT interval, to reduce the risk of near-fatal arrhythmias during the use of levosimendan.

Risk factors for cardiovascular disease in primary Sjögren's syndrome (pSS): a 20-year follow-up study

INTRODUCTION

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by a chronic grade of inflammation. Cardiovascular events represent the major causes of morbidity and mortality in patients with inflammatory rheumatic diseases; however, the significance and prevalence of cardiovascular disease in patients with pSS remain unclear.

OBJECTIVE

To determine the clinical significance of cardiovascular disease in pSS and analyze the risk of cardiovascular disease according to glandular/extraglandular involvement and positivity to anti-Ro/SSA and/or anti-La/SSB autoantibodies.

METHODS

A retrospective study including patients diagnosed with pSS fulfilling the 2016 ACR/EULAR classification criteria was followed and evaluated in our outpatient clinic between 2000 and 2022. The prevalence of cardiovascular risk factors with pSS was evaluated, and a possible association with clinical and immunological characteristics, the treatments received, and the impact on cardiovascular disease were determined. Univariate and multivariate regression analyses were performed in an attempt to determine potential risk factors associated with cardiovascular involvement.

RESULTS

A total of 102 pSS patients were included. Eighty-two percent were female, with a mean age of 65±24 years and a disease duration of 12.5 ±6 years. Thirty-six patients (36%) had at least one cardiovascular risk factor. Arterial hypertension was diagnosed in 60 (59%) patients, dyslipidemia in 28 (27%), diabetes in 15 (15%), obesity in 22 (22%), and hyperuricemia in 19 (18%). History of arrhythmia was found in 25 (25%), conduction defects in 10 (10%), arterial peripheral vascular disease in 7 (7%), venous thrombosis in 10 (10%), coronary artery disease in 24 (24%), and cerebrovascular disease in 22 (22%) of patients. Patients with extraglandular involvement had a higher prevalence of arterial hypertension (p=0.04), dyslipidemia (p=0.003), LDL mean values (p=0.038), hyperuricemia (p=0.03), and coronary artery disease (p=0.01) after adjusting for age, sex, disease duration, and the significant variables in the univariate analysis. Patients with Ro/SSA and La/SSB autoantibodies had a substantially higher risk of hyperuricemia (p=0.01), arrhythmia (p=0.01), coronary artery disease (p=0.02), cerebrovascular disease (p=0.02), and venous thrombosis (p =0.03). In the multivariate logistic regression analysis, higher odds of cardiovascular risk factors were associated with extraglandular involvement (p=0.02), treatment with corticosteroids (p=0.02), ESSDAI>13 (p=0.02), inflammatory markers including ESR levels (p 0.007), and serologic markers such as low C3 levels (p=0.03) and hypergammaglobulinemia (p=0.02).

CONCLUSIONS

Extraglandular involvement was associated with a higher prevalence of arterial hypertension, dyslipidemia, hyperuricemia, and coronary artery disease. Anti-Ro/SSA and anti-La/SSB seropositivity was associated with a higher prevalence of cardiac rhythm abnormalities, hyperuricemia, venous thrombosis, coronary artery disease, and cerebrovascular disease. Raised inflammatory markers, disease activity measured by ESSDAI, extraglandular involvement, serologic markers including hypergammaglobulinemia and low C3, and treatment with corticosteroids were associated with a higher risk for cardiovascular comorbidities. Key Points • Patients with pSS are vulnerable to cardiovascular risk factors. There is an interconnection between extraglandular involvement, disease activity, inflammatory markers, and cardiovascular risk comorbidities. • Anti-Ro/SSA and anti-La/SSB seropositivity was associated with a higher frequency of cardiac conduction abnormalities, coronary artery disease, venous thrombosis, and stroke. • Hypergammaglobulinemia, elevated ESR, and low C3 are associated with a higher prevalence of cardiovascular comorbidities. • Valid risk stratification tools to help with prevention and consensus on the management of CVDs in pSS patients are warranted.

The Spectrum of Extraglandular Manifestations in Primary Sjögren's Syndrome

Extraglandular manifestations (EGMs) in primary Sjogren's syndrome (pSS) represent the clinical expression of the systemic involvement in this disease. EGMs are characterized by a wide heterogeneity; virtually any organ or system can be affected, with various degrees of dysfunction. The existing gaps of knowledge in this complex domain of extraglandular extension in pSS need to be overcome in order to increase the diagnostic accuracy of EGMs in pSS. The timely identification of EGMs, as early as from subclinical stages, can be facilitated using highly specific biomarkers, thus preventing decompensated disease and severe complications. To date, there is no general consensus on the diagnostic criteria for the wide range of extraglandular involvement in pSS, which associates important underdiagnosing of EGMs, subsequent undertreatment and progression to severe organ dysfunction in these patients. This review article presents the most recent basic and clinical science research conducted to investigate pathogenic mechanisms leading to EGMs in pSS patients. In addition, it presents the current diagnostic and treatment recommendations and the trends for future therapeutic strategies based on personalized treatment, as well as the latest research in the field of diagnostic and prognostic biomarkers for extraglandular involvement in pSS.

Pathophysiology of Cav1.3 L-type calcium channels in the heart

Ca²⁺ plays a crucial role in excitation-contraction coupling in cardiac myocytes. Dysfunctional Ca²⁺ regulation alters the force of contraction and causes cardiac arrhythmias. Ca²⁺ entry into cardiomyocytes is mediated mainly through L-type Ca²⁺ channels, leading to the subsequent Ca²⁺ release from the sarcoplasmic reticulum. L-type Ca²⁺ channels are composed of the conventional Ca_v1.2, ubiquitously expressed in all heart chambers, and the developmentally regulated Ca_v1.3, exclusively expressed in the atria, sinoatrial node, and atrioventricular node in the adult heart. As such, Ca_v1.3 is implicated in the pathogenesis of sinoatrial and atrioventricular node dysfunction as well as atrial fibrillation. More recently, Ca_v1.3 de novo expression was suggested in heart failure. Here, we review the functional role, expression levels, and regulation of Ca_v1.3 in the heart, including in the context of cardiac diseases. We believe that the elucidation of the functional and molecular pathways regulating Ca_v1.3 in the heart will assist in developing novel targeted therapeutic interventions for the aforementioned arrhythmias.