title: Effect of Vitamin D on Peripheral Blood Mononuclear Cells from Patients with Psoriasis Vulgaris and Psoriatic Arthritis.
abstract: BACKGROUND
  Psoriasis, a chronic skin disease with or without joint inflammation, has increased circulating proinflammatory cytokine levels. Vitamin D is involved in calcium homeostasis, bone formation, osteoclastogenesis and osteoclast activity, as well as regulation of immune response. We aimed to study osteoclast differentiation and cytokine secretion of peripheral blood mononuclear cells (PBMCs) from patients with psoriasis vulgaris and psoriatic arthritis, in response to 1,25(OH)2D3.
  
  
  METHODS
  Serum levels of bone turnover markers were measured by ELISA in patients with psoriasis vulgaris and psoriatic arthritis, and healthy controls. PBMCs were isolated and cultured with or without RANKL/M-CSF and 1,25(OH)2D3. Osteoclast differentiation and cytokine secretion were assessed.
  
  
  RESULTS
  Psoriatic arthritis patients had lower osteocalcin, as well as higher C-telopeptide of type I collagen and cathepsin K serum levels compared with psoriasis vulgaris patients and controls. RANKL/M-CSF-stimulated PBMCs from psoriatic arthritis patients produced higher proinflammatory cytokine levels and had a differential secretion profile in response to 1,25(OH)2D3, compared with psoriasis vulgaris and control PBMCs.
  
  
  CONCLUSIONS
  Our data confirmed altered bone turnover in psoriatic arthritis patients, and demonstrated increased osteoclastogenic potential and proinflammatory cytokine secretion capacity of these PBMCs compared with psoriasis vulgaris and controls. 1,25(OH)2D3 abrogated these effects.
authors.affiliation: Department of Dermatology, Jena University Hospital, Jena, Thüringen, Germany.
authors.forename: Susana
authors.initials: S
authors.lastname: Cubillos
authors.affiliation: Department of Dermatology, Jena University Hospital, Jena, Thüringen, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Krieg
authors.affiliation: Department of Dermatology, Jena University Hospital, Jena, Thüringen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Norgauer
mesh_terms: D015535:Arthritis, Psoriatic / Q000097:blood*; D002116:Calcitonin / Q000097:blood; D002117:Calcitriol / Q000494:pharmacology*; D002118:Calcium / Q000097:blood; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D009000:Monocytes / Q000187:drug effects*; D010010:Osteoclasts / Q000473:pathology; D011565:Psoriasis / Q000097:blood*
chemical_list: D016207:Cytokines; D002116:Calcitonin; D002117:Calcitriol; D002118:Calcium