C4A and systemic lupus erythematosus: The elevated CVD risk in SLE patients has been attributed in large part to its pro-inflammatory state [45] and this is reflected in the SLE-related variables that were selected for SLECRISK: increased disease duration, disease activity, renal dysfunction, positive anti-dsDNA, -RNP,- Ro antibodies, lupus anticoagulant, and low C4.