RNPC3 and pulmonary arterial hypertension: K-means cluster analysis was used for clustering, with regression analyses predicting mortality.<h4>Result</h4>Analysing 111 SLE PAH patients revealed three clusters: Cluster 1 (CL1)-Sm-RNP positive (n=48), Cluster 2 (CL2)-no specific autoantibodies (n=36), and Cluster 3 (CL3)-multiple autoantibody positivity (n=27) (Smith, Sm-RNP, nucleosome, histone).