Characterization of Cutaneous Microbiota in the Psoriasis Pathogenesis

Study Overview
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Brief Summary
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The skin harbors a complex and dynamic microbiota constituted by numerous microorganisms that live in symbiosis with the host. The specific etiology of psoriasis is still not-well understood; nonetheless several studies highlighted that that the skin microbiota could have a pivotal role in the maintenance and/or progression of the disease, acting as microbial predictor of psoriasis however. The aim of the present study was to characterize the microbiota of cutaneous biopsies associated to guttate and vulgaris psoriasis, both considering lesion and healthy skin belonging to the same psoriatic subject.

Detailed Description
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Twelve individuals with guttate psoriasis and 12 individuals with vulgaris psoriasis have been enrolled at Dermatological Unit of IRCCS Galeazzi Institute, Milan. Patients selected for the psoriasis vulgaris group had a course of disease stable for at least 1 month before collection. The second group presented guttate psoriasis, defined as eruptive, that is characterized by a rapid appearance and worsening of the clinical presentation within the month preceding the visit. From each participant, a punch was used to obtain a cutaneous sample from both a lesion and healthy skin area of 2 mm2 belonging to the left gluteus, for a total of 48 biological samples. Participants were selected and included in the study according to the following criteria: i) over 18 years of age; ii) use of a free-preservatives soap with moisturizing function; iii) no use of probiotics; iv) no use of antibiotics; v) no treatment with corticosteroids, biological drugs, methotrexate or retinoids in the month prior the sampling; vi) no use of topical corticosteroids, vitamin D derivatives or phototherapy; vi) no chronic or systemic infections; vii) no cutaneous acute infections; viii) no allergy to pollen, food and drugs ix) no pets. Informed consent was obtained from all subjects. A metagenomics approach, performed by the use of Ion torrent Personal machine, were used to investigate the bacterial composition of the skin microbiota associated to each samples collected. After sequencing, the data analysis were focused on the bacterial biodiversity and microbial networks existing in the skin microbiota to evaluate a hypothetical role of bacteria in the complex pathophysiological mechanisms involved in psoriasis.

Official Title
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Characterization of Cutaneous Microbiota and Evaluation of the Antimicrobial Peptides Roles in the Psoriasis Etiopathogenesis

Conditions
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Psoriasis

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: over 18 years of age; use of a free-preservatives soap with moisturizing function, applied once a day;pets. Exclusion Criteria: no use of probiotics in the month prior the sampling; no use of antibiotics in the month prior the sampling; no treatment with corticosteroids, biological drugs, methotrexate or retinoids in the month prior the sampling; no use of topical corticosteroids, vitamin D derivatives or phototherapy in the month prior the sampling; no chronic or systemic infections; no cutaneous acute infections during sampling; no allergy to pollen, food and drugs no pets.

Ages Eligible for Study
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Minimum Age: 18 Years


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 vulgaris<br>Pathological conditions stable for at least 1 month before collection. One punch biopsy from each patient, was taken from a big reddish and scaly plaque and another punch biopsy from the perilesional healthy skin. | |
| Psoriasis guttate<br>One punch biopsy from each patient, was taken from a small reddish and scaly plaque and another punch biopsy from the perilesional healthy skin. | |
| Healthy skin of psoriasis vulgaris<br>Healthy skin area of 2mm2 belonging to the left gluteus from patients affected by psoriasis vulgaris | |
| Healthy skin of psoriasis guttate<br>Healthy skin area of 2mm2 belonging to the left gluteus rom patients affected by psoriasis guttate | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of the Psoriasis Area and Severity Index (PASI) | It is a measurement of psoriasis severity . | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Chao's index | It is a measure of bacterial biodiversity | 1 year | 
| Microbial abundance | It is a measure of bacterial amount | 1 year | 
| Spearman's correlation | It a measure of the bacterial interactions | 1 year | 
| Shannon's index | It is a measure of bacterial biodiversity | At the beginning of the study | 
| Simpson's index | It is a measure of bacterial biodiversity | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Psoriasis Guttate, Psoriasis vulgaris