Characteristics and survival of patients with anti-U1RNP antibodies in connective tissue disease associated pulmonary arterial hypertension.

Abstract Pulmonary arterial hypertension (PAH) is a severe complication of connective tissue diseases (CTDs). This study aimed to study the clinical and hemodynamic characteristics and survival of patients with anti-U1RNP antibodies in CTD-PAH, with a focus on systemic sclerosis (SSc)-PAH. We implemented a prospective database that included CTD-PAH patients with clinical, autoantibody and mortality data. We compared clinical and hemodynamic characteristics accordingly to anti-U1RNP antibodies status. We then assessed whether anti-U1RNP antibodies could be a prognostic factor in CTD-PAH with a focus on SSc-PAH. A total of 342 CTD-PAH patients were studied, of whom 36 (11%) were anti-U1RNP antibodies positive. Patients with anti-U1RNP antibodies were younger and less functionally impaired than anti-U1RNP negative patients in CTD- and SSc-PAH. Hemodynamic parameters were similar between anti-U1RNP positive and negative patients. In CTD-PAH, anti-U1RNP positivity was associated with a decreased mortality in univariable analysis (HR 0.34 [95% CI: 0.18-0.65]; p