Adipose Derived Mesenchymal Stem Cell Characteristics in Anal Fistulas

Study Overview
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Brief Summary
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This study investigated the cellular and molecular characteristics of AT-MSCs obtained from autologous AT therapy in patients with high transphincteric perianal fistulas of crytoglandular origin. Adipose tissue was injected into anal fistulas. Characteristics of adipose tissue mesenchymal stemcells (AT-MSC) was investigated and compared in patients with fistula that healed after the treatment (responders) to patients who failed to heal (non-responders)

Detailed Description
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Injection with allogene or autologous stem cells has been reported to be efficient treatment of perianal fistulas. An alternative to this treatment could be injection with freshly collected autologous adipose tissue. In this study 27 patients with cryptoglandular anal fistulas were treated with freshly collected autologous adipose tissue.A clinical assessment of the patient prior to inclusion was undertaken and a loose seton placed for at least 6 weeks prior to fat injection. An MRI of the pelvis was performed before inclusion. Fistulas with secondary tracts and/or cavities were excluded. The operation was performed in one procedure including liposuction and injection of adipose tissue. A sample of adipose tissue from all 27 patients was analyzed. AT-MSCs were isolated and characterized using cellular and molecular analyses. Clinical and MRI-scanning evaluation of fistula healing and evaluation of ano-rectal function was performed after 6 months. AT-MSCs phenotype was compared between responders and non-responders with respect to fistula healing. The evaluation of the AT-MSCs was performed in a blinded manner.

Official Title
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Identification of Molecular Differences of Adipose-derived Mesenchymal Stem Cells Between Non- Responders and Responders in Treatment of Transsphincteric Perianal Fistulas Using Autologous Fat Graft Injection

Conditions
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Perianal Fistula, Adipose Tissue, Tissue Transplantation

Intervention / Treatment
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* Procedure: Injection of autologous adipose tissue in anal fistula


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: high trans-sphincteric fistulas fistula confirmed and classified by an MRI. seton (> 6 weeks) prior to fat injection informed, written consent. Exclusion Criteria: Anovaginal fistula Active sepsis IBD, immunodeficiency, prior pelvic irradiation and malignancy Insulin dependent diabetes More than 4 prior attempts of fistula closure Tobacco smoking or nicotine substitution 8 weeks prior to fat injection. Pregnancy Psychiatric disorders BMI ≥ 35 or BMI<20 Active tuberculosis Patient less than 18 years Unable to undergo MRI

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Injection with adipose tissue<br>Injection of freshly collected autologous adipose tissue | Procedure: Injection of autologous adipose tissue in anal fistula<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Investigation of cell proliferation of AT-MSCs | Cell proliferation of AT-MSCs evaluated as number of cells/per day | At start of treatment | 
| Investigation of differentiation potential of AT-MSCs to differentiate into adipocyte | Differentiation potential of AT-MSCs: to differentiate into adipocyte measured by Oil-Red O staining and gene expression of adipogenic markers (PPARg and LPL normalized to housekeeping gene beta actin) presented as a Fold change to undifferentiated cells (arbitrary units) | At start of treatment | 
| Investigation of differentiation potential of AT-MSCs to differentiate into osteoblast | Differentiation potential of AT-MSCs: to differentiate into osteoblast measured by Alizarin S staining and gene expression of osteogenic markers (BGALP and RUNX2 normalized to housekeeping gene beta actin) presented as a Fold change to undifferentiated cells (arbitrary units) | At start of treatment | 
| Measurement of gene expression profile of AT-MSCs | Gene expression of proinflammatory (NFKB, TNFa, IL1B, IL6) and senescence associated molecules(CDKN2A, TP53, TGFB1, VEGFA, IFNG, IL6) of AT-MSCs in relation to the outcome of fistula treatment (i.e. comparison between responders and non-responders). The data are normalized to housekeeping gene beta actin (arbitrary units) | At start of treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Healing of anal fistula after treatment | Clinical healing defined as closure of the internal and external fistula opening and no discharge evaluated as success rate of the healing in (%) | 6 months after last injection of autologous adipose tissue | 
| Evaluation of fistula healing after treatment | A combination of Clinical and MRI healing defined as closure of the internal and external fistula opening and no discharge and no fluid filled fistula tracts on evaluated as success rate of the healing in (%) | 6 months after last injection of autologous adipose tissue | 
| Functional gastroenterological outcome after treatment | Anal continence evaluated as the St. Mark's Score (0-24) | 6 months after last injection of autologous adipose tissue | 
| Defecation disorder evaluation after treatment | Defecation disorders evaluated as Altomare Obstructed Defecation Score (0-31) | 6 months after last injection of autologous adipose tissue | 
| Functional urological outcome after treatment | Urinary incontinence evaluated as ICIQ-UI-SF (0-21) | 6 months after last injection of autologous adipose tissue | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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autologous adipose tissue, mesenchymal stem cells, perianal fistula