title: Elevated serum prolactin levels as a marker of inflammatory arthritis in psoriasis vulgaris.
abstract: OBJECTIVE
  Psoriasis vulgaris (PV) is complicated in up to 40% patients by the inflammatory joint disease psoriatic arthritis (PsA). Neither the aetiology of the arthritis nor specific laboratory markers for its disease activity have been clearly elucidated. Prolactin (PRL) acts as a cytokine with immunomodulatory functions and plays a role in skin and joint biology. The results on PRL however as a marker are unclear. The aim of this study was to confirm whether serum PRL levels reflect systemic complications of PV, like inflammatory joint disease and/or can serve as a marker of disease activity in both cases.
  
  
  METHODS
  A total of 70 patients with PV without arthritis and 40 patients suffering from PsA were included. In all patients, we determined skin disease activity according to the PASI index and in PsA, active disease assessed as swollen or tender joints. The control group included 27 age and sex matched healthy individuals. The concentration of PRL in the serum was measured by immunoradiometric assays.
  
  
  RESULTS
  The PRL serum levels were significantly increased in PsA patients (299.2±28.29 mIU/L) compared to PV only patients (201.4.2±11.72 mIU/L), P = 0.0003 and healthy individuals (198.2±15.31 mIU/L), P = 0.007. The serum PRL levels in PsA with active disease 336.8±42.50 (mIU/L) were higher than in PV and controls, P < 0.0001 and P = 0.002 respectively. In PV only patients, there was no correlation between PASI and PRL levels.
  
  
  CONCLUSIONS
  Our results showed that PRL serum levels are a marker of active arthritis in PsA and reflects systemic complication rather than local skin activity.
authors.affiliation: Institute of Rheumatology, Na Slupi 4, 12850 Prague 2, Czech Republic.
authors.forename: Marketa
authors.initials: M
authors.lastname: Husakova
authors.affiliation: Department of Dermatology, Stadt. Klinikum Gorlitz, Girbingsdorfer Strasse 1-3, Gorlitz, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Lippert
authors.affiliation: Institute of Rheumatology, Na Slupi 4, 12850 Prague 2, Czech Republic.
authors.forename: Jiri
authors.initials: J
authors.lastname: Stolfa
authors.affiliation: Institute of Rheumatology, Na Slupi 4, 12850 Prague 2, Czech Republic.
authors.forename: Liliana
authors.initials: L
authors.lastname: Sedova
authors.affiliation: The Clinic of Dermatology and Venereology, 3rd Faculty of Medicine, Charles University in Prague and Faculty Hospital of Kralovske Vinohrady, Prague.
authors.forename: Petr
authors.initials: P
authors.lastname: Arenberger
authors.affiliation: 3rd Department of Internal Medicine - Department of Endocrinology and Metabolism, 1st Faculty of Medicine, Charles University in Prague and General University Hospital in Prague.
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Lacinova
authors.affiliation: Institute of Rheumatology, Na Slupi 4, 12850 Prague 2, Czech Republic.
authors.forename: Karel
authors.initials: K
authors.lastname: Pavelka
mesh_terms: D000328:Adult; D015535:Arthritis, Psoriatic / Q000175:diagnosis; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015592:Immunoradiometric Assay; D008297:Male; D011388:Prolactin / Q000378:metabolism*; D011565:Psoriasis / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; D011388:Prolactin
keywords: arthritis; immune cells; prolactin; psoriasis vulgaris; psoriatic arthritis; serum levels