CRP and immunoglobulin G4-related sclerosing disease: Compared to patients with IgG4-RD who lack periaortitis or periarteritis, those with IgG4-related PAO/PA typically present with higher white blood cell counts, erythrocyte sedimentation rate (ESR), and high-sensitivity CRP levels but have lower levels of blood hemoglobin, serum IgG4, and IgE (20).