To analyse the prevalence, the clinical characteristics, the overall survival and the event-free survival (EFS) of Systemic Sclerosis (SSc) patients who express anti- U11/U12 RNP (RNPC-3) antibodies.A total of 447 SSc patients from Barcelona (n = 286) and Milan (n = 161) were selected. All samples were tested using a particle-based multi-analyte technology. We compared anti-RNPC-3 positive and negative patients. Epidemiological, clinical features and survival were analyzed. End-stage lung disease (ESLD) was defined if the patient developed FVC < 50% of predicted, needed oxygen therapy or lung transplantation. EFS was defined as the period of time free of either ESLD or death.Nineteen of 447 (4.3%) patients had anti-RNPC-3 antibodies and interstitial lung disease (ILD) was more frequent (11, 57.9% vs. 144, 33.6%, p = 0.030) in individuals with anti-RNPC-3 antibodies. More patients reached ESLD in the positive group (7, 36.8% vs. 74, 17.3%, p = 0.006), and a higher use of non-glucocorticoid immunosuppressive drugs was observed (11, 57.9% vs. 130, 30.4%, p = 0.012). Anti-RNPC-3 positive patients had lower EFS, both in the total cohort (log-rank p=0.001), as well as in patients with ILD (log-rank p=0.002). In multivariate Cox regression analysis diffuse cutaneous subtype, age at onset, the presence of ILD or pulmonary arterial hypertension, and the expression of anti-RNPC-3 positivity or anti-topoisomerase I were independently associated with worse EFS.The presence of anti-RNPC-3 was associated with higher frequency of ILD and either ESLD or death. These data suggest anti-RNPC-3 is an independent poor prognosis antibody in SSc, especially if ILD is also present.
Authors' Names Eduardo Luis Callejas-Moraga, Alfredo Guillén- Del-Castillo, Janire Perurena-Prieto, Maria Teresa Sanz-Martínez, Vicente Fonollosa-Pla, Karen Lorite-Gomez, Adriana Severino, Chiara Bellocchi, Lorenzo Beretta, Michael Mahler, Carmen P Simeón-Aznar