Recirculating Memory T Cells in the Pathogenesis of Psoriatic Arthritis and Cutaneous Psoriasis

Study Overview
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Brief Summary
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The aim of the study is to investigate the link between pro-inflammatory T cells responses arising in the skin in patients with cutaneous psoriasis and those present in the joints of patients developing psoriatic arthritis. The study is based on the hypothesis that a fraction of T cells with memory phenotype can recirculate from the skin and relocalize at extracutaneous sites including enthesis or synovial tissue thus propagating the pro-inflammatory cycle. This could represent a pathogenic mechanism in the development of PsA. The main aim of the study is to define the phenotypic and functional differences of circulating T cells in patients cutaneous psoriasis, patients with psoriatic arthritis and in control group of healthy subject. To this end the investigators analyze the expression of cell surface markers of central memory (TCM), effector memory (TEM) and effector (Teff) cells, within this subsets the investigators evaluate the expression of chemokine receptors as well as skin and tissue homing molecules. There will be also an evaluation of the T cell polarization towards Th1/Tc1 or Th17/Tc17 phenotype by evaluating the cytokine expression profile. In selected patients with PsA the researchers analyze in parallel the phenotype and the cytokine profile of T cell subpopulations in peripheral blood and in synovial fluid, The results of this study could possibly allow to define distinctive features of circulating T cells in patients with PsA and to understand the link between circulating and synovial fluid T cells in patients with PsA.

Official Title
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Recirculating Memory T Cells in the Pathogenesis of Psoriatic Arthritis and Cutaneous Psoriasis

Conditions
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Psoriasis, Psoriatic Arthritis

Intervention / Treatment
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* Other: blood sample collection
* Procedure: Synovial Fluid collection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with a diagnosis of cutaneous psoriasis without clinical signs of PsA, Patients with a diagnosis of PsA Healthy subjects with a negative family and personal anamnesis for psoriasis. Absence of acute and chronic systemic or cutaneous infections during sample collections. Exclusion Criteria: Treatment with cyclosporin A, methotrexate, systemic corticosteroids or any other immunosuppressant agent within 3 weeks before the blood samples collections.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Psoriasis<br>Patients with psoriasis vulgarism without clinical signs of PsA | Other: blood sample collection<br>* Blood samples are collected from patients with psoriasis vulgaris and patients with psoriatic arthritis following the routine procedure. Blood samples will also be collected from healthy control subjects.<br>|
| Psoriatic Arthritis (PsA)<br>Patients with a diagnosis of psoriatic arthritis and cutaneous psoriasis | Other: blood sample collection<br>* Blood samples are collected from patients with psoriasis vulgaris and patients with psoriatic arthritis following the routine procedure. Blood samples will also be collected from healthy control subjects.<br>Procedure: Synovial Fluid collection<br>* Synovial fluid is collected when prescribed in patients with psoriatic arthritis<br>|
| Control group<br>Healthy subjects | Other: blood sample collection<br>* Blood samples are collected from patients with psoriasis vulgaris and patients with psoriatic arthritis following the routine procedure. Blood samples will also be collected from healthy control subjects.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of the percentage of different subsets of memory T cells in the circulation of patients with psoriasis, patients with psoriatic arthritis and a control group of healthy subject. | Central memory, Effector memory and Effector cell markers are evaluated in circulating CD4 and CD8 T cells. Within these subsets the expression of chemokine receptors is also evaluated and we define the cytokine secretion profile for each subset. | At time of blood collection | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation between the circulating percentage of individual subsets of CD4 and CD8 T cells and the clinical disease parameters: Psoriasis Area and Severity Index (PASI) Score and serum level of C reactive protein (CRP) | For each subsets it is calculated the correlation between the percentage in the circulation and either the Psoriasis Area and Severity Index (PASI) score or the serum level of C reactive protein | At time of blood collection | 
| Parallel analysis of the phenotype of CD4 and CD8 T cells in the circulation and in synovial fluid of patients with psoriatic arthritis. | Phenotype and functional analysis of T Cells | At time of blood and synovial fluid collection | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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T-cells, circulation, synovial fluid, psoriasis, psoriatic arthritis