Clinical value of anti-DSG2 antibodies in arrhythmogenic right ventricular cardiomyopathy: a real-life experience

Abstract Background/Introduction Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease leading to ventricular arrhythmias and heart failure. The diagnosis is challenging and currently based on a set of clinical criteria with limited sensitivity and specificity. Anti-desmoglein-2 (DSG2) antibodies were previously found in patients diagnosed with ARVC, while they were absent in both healthy controls and athletes. Purpose The study aimed to evaluate the diagnostic value of anti-DSG2 antibodies by comparing their concentration in patients with ARVC and other right ventricular diseases. Additionally, the prognostic value of the biomarker was assessed. Methods A cohort of 101 patients with a definite diagnosis of ARVC according to the 2010 Task Force criteria was enrolled (64 males, mean age 47 ± 16 years). The control group included patients with Ebstein anomaly and Eisenmenger syndrome (16 and 21 subjects, respectively). Anti-DSG2 antibody concentration was assessed using enzyme-linked immunosorbent assay (ELISA). After that, an ARVC cohort was followed for 3.9 ± 1.6 years for the occurrence of the primary endpoint of cardiac death or heart transplantation (HTx) and major arrhythmic events (MAEs) defined as ventricular fibrillation, sustained ventricular tachycardia (sVT) or appropriate implantable cardioverter-defibrillator intervention. Results The median anti-DSG2 antibody concentration presented as ELISA optical density (OD) reached 1.36 [0.54-2.15] in the ARVC cohort, while it was 0.4 [0.34-0.54] in Ebstein anomaly group and 0.36 [0.28-0.58] in the Eisenmenger syndrome group. There was a significant difference in antibody levels between ARVC and both control groups (p < 0.001, Figure 1). The cutoff value for the diagnosis of ARVC was 0.774, with 72.3% sensitivity and 100% specificity (AUC = 0.823). After dividing the ARVC cohort according to the designated cutoff point, the anti-DSG2-positive subgroup was significantly younger (44.5 ± 15.4 vs. 52.8 ± 15.5 years, p = 0.017) and more likely to have a history of sVT (68.5% vs. 46.4%, p = 0.041). There was no difference regarding sex, presence of PKP2 or DSG2 mutations, previous sports activities, history of sudden cardiac arrest or syncope, right ventricular dimensions and systolic function, left ventricular ejection fraction and heart failure symptoms. This threshold was not predictive for the primary endpoint and MAEs. However, a more stringent cutoff value for anti-DSG2 level (1.021) was found to predict death or HTx (HR [95% CI] 4.56 [1.05-19.76], p = 0.026, Figure 2). Conclusions The concentration of anti-DSG2 antibodies is significantly higher in ARVC compared to other right ventricular diseases. A high antibody level is prognostic for death or HTx in ARVC.Figure 1Figure 2