CALR and systemic lupus erythematosus: Autoantibodies against surface-exposed Ro epitopes are specific for a subset of SLE patients showing positivity of anti-Ro60 without anti-La, whereas double-positivity of anti-Ro60 and anti-La is consequent to intermolecular spreading from Ro to La, in which antigens are exposed on late ACs or released from necrotic ACs [48].