RNPC3 and arthritic joint disease: Multivariate Cox regression analysis revealed independent risk factors for AVN were age at SLE onset≤30, arthritis, positive anti-RNP antibody, existing organ damage (SDI≥1) at registration, and higher maximum daily dose of GC at registration, which were also included in the risk scoring predictive model to discriminate SLE patients with higher risk of AVN from those with lower risk.