The efficacy of TNF alfa inhibitors in the treatment of psoriasis has been documented in many studies.

Their effect on dendritic cells has been scarcely studied. TNF- α has a central role in dendritic cell biology, both for their maturity and mobilization of peripheral tissues to secondary lymphoid organs.

The primary objectives of this study are:

• To document absolute number, density of immune infiltrate and dendritic cells and inflammatory cytokines expression pattern (particularly IFN α and IL-32) in psoriasic lesions vs normal skin of the same patient
• To describe changes in such cell numbers and expression patterns upon 16 weeks treatment with TNF alfa inhibitors.

Inclusion Criteria:

• Male and female subjects > 18 years of age, affected by moderate to severe psoriasis

• Subject has had clinical diagnosis of psoriasis for at least 12 months, stable plaque psoriasis for at least 2 months before screening (subjects with concurrent psoriatic arthritis may be enrolled).

• Subject is naıve to TNF-antagonist therapy and efalizumab.

• Subjects are considered eligible according to the following tuberculosis screening criteria:

  1. Have no history of latent or active TB prior to screening;
  2. Have no signs or symptoms suggestive of active TB upon medical history and/or physical examination;
  3. Within 1 month prior to the first administration of study medication, have negative diagnostic tuberculin skin test.

• Normal chest X-ray within 3 months prior to screening with no evidence of malignancy, infection, current or old TB.

• Subjects' screening and baseline clinical data must be within the normal limit, including the results of medical history, physical examination and laboratory evaluation (complete blood count, serum values for liver enzymes, bilirubin, glucose, albumin, creatinine and urine analysis).

• Willing and able to comply with the protocol requirements for the duration of the study.

• Women of childbearing potential must be using adequate birth control measure throughout the study and for 150 days (5 months) after study completion.

Exclusion Criteria:

• Pregnant or breast-feeding women, or women who are planning pregnancy.
• Patients not suitable for TNF alfa inhibitors therapy