It's clearly known that lymphocyte activation in particular Th17 response, plays a major role in the development of plaque psoriasis. New therapies targeting this pathway are showing great clinical efficacy in patients with moderate to severe plaque psoriasis.

Pioneering observations have shown that the expression of Cav1.4 channels in Th17 lymphocytes and they're functional role is supported by the inhibition of IL-17 production by a pharmacological inhibitor of Cav1 channels that is effective in a mouse model of Psoriasis.

This data strongly suggest that the Cav1.4 channel, via its involvement in the signalling responsible for the production of Th17 cytokines represents an interesting therapeutic target in Psoriasis.

The aim of the study is to explore biological functions related to the activation of the Cav1.4 pathway in Psoriasis.

• Evaluate the expression of Cav1.4 calcium channels by Th17 lymphocytes from plaque psoriasis.

• To assess:

  • The role of Cav1.4 channels on the activation of Th17 lymphocytes
  • The transcriptomic signature relating to the signalling channel Cav1.4
  • The epigenetic signature, in particular changes in overall methylation and specific promoter methylation

Inclusion Criteria:

• Group 1 : Subject with plaque psoriasis (diagnosis confirmed by dermatologist) with a plaque IGA score ≥ 3
• Group 2 : Subject with atopic dermatitis according to the UK Working party criteria with an IGA plaque score ≥3

Exlusion Criteria:

• Group 1 : Other chronic inflammatory dermatosis than plaque psoriasis at the sites to be sampled
• Group 2 : Other chronic inflammatory dermatosis than Atopic Dermatitis at the sites to be sampled
• For both groups: Ongoing treatment with calcium channel blockers
• For both groups: Any current topical treatment on the biopsied or systemic plaque for psoriasis or AD (including phototherapy)