The objective of the resarch is to study the cytokine profile of patients with psoriatic arthritis and psoriasis in order to better understand the pathophysiology of the disease and the contribution of cytokines to the presence or absence of joint involvement. This research will compare cytokines levels in sera, in PBMC culture after LPS or CD3/CD28 agonist antibodies, and in skin biopsy.

Psoriatic arthritis and Cutaneous Psoriasis are polygenic inflammatory disorders with high burden on the quality of life of patients. Pathophysiology of those disease remain incompletely understood. Recent publications seem to demonstrate an implication of IL-1 family cytokines in the pathogenesis of both diseases. In the literature, results are discordant and focus mainly on cytokines levels in serum of patients. Moreover, few studies compare psoriatic arthritis patients with cutaneous psoriasis patients. We propose here to study cytokines profiles of patients with those conditions in sera, after ex-vivo stimulation of peripheral blood mononuclear cells, and in skin biopsies.

Inclusion criteria:

• For psoriasis patients :

  • Age over 18 years old
  • Signed informed consent
  • 5 year old psoriasis at least
  • At least one skin lesion over 2 cm
  • Without any articular symptoms
  • Without any DMARDs
  • Without anticoagulant treatments or coagulation disease
  • With normal articular and enthesis sonography

• For psoriatic arthritis patients :

  • Age over 18 years old
  • Signed informed consent
  • Psoriatic arthritis according to CASPAR criteria
  • Without any DMARDs
  • Without anticoagulant treatments or coagulation disease
  • With at least one synovitis at inclusion

• For controls

  • Age and sex matched with a patient without any rheumatic or dermatologic medical conditions
  • No treatment with corticosteroïds or non-steroïdial anti-inflammatory drugsAge over 18 years old

Exclusion criteria:

▪ For psoriasis patients :

• Joint damage according to CASPAR criteria
• Echography activity in favor of chronic inflammatory rheumatism
• For patients and controls:
• Without social protection rights
• People under judiciary protection, of less than 18 years old, pregnant woman, breast feeding women, jailed patients.

Publication of the results

Results will be published in a scientific journal

Upon reasonable request to authors after article publication