PROCR and systemic lupus erythematosus: Anti-EPCR activity was detected in 1 of 18 patients with Sjögren’s syndrome and 4 of 93 patients with systemic lupus erythematosus (SLE); anti-SR-BI activity was detected in 1 of 14 patients with microscopic polyangiitis and 4 of 93 patients with SLE.