Human Subcutaneous Inflammatory Response to Glucose Sensors

Study Overview
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Brief Summary
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The aim of the study is to describe the inflammatory response to enzimatic glucose sensors after 10 days of use and to evaluate the relationship between the magnitude of the FBR (foreign body response) with the accuracy of the sensor (MARD)

Detailed Description
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Eighteen Type 1 DM patients are going to be included. Primary Objectives To define the intra-individual and inter-individual variability of the macrophage count around the sensor To assess whether there is a relationship between the number of macrophages, fibrosis and MARD of the MCG registry. Secondary Objectives To describe the histology of tissue response. This description will include: HE stain: cell types, arrangement, vascular structures, signs of hemorrhage-clot. Giemsa stain: mast cells. Masson's trichrome stain: str. vascular. Immunohistochemistry: Vascular assessment, characterization of macrophages Each patient will have 1 glucose sensor inserted in the non-dominant arm. During the useful life of the sensor (10), a minimum of 4 capillary blood glucose determinations/day will be performed The sensor has a length of 8 mm and a diameter of 0.4 mm. All the necessary material will be provided, including a control diary to help the patient remember to carry out the self-control and set its time distribution. On the last day of sensor use, it will be removed and a 4-mm punch skin biopsy will be performed 5 minutes later. Tissue samples will be fixed in 4% formaldehyde solution, paraffin blocks made and sectioned. The resulting samples will be stained Semiquantitative determination of lymphocytes, neutrophils, mast cells, macrophages will be performed; fibrin, fibrosis, vascular proliferation and karyorrhexis In all cases, a quantitative immunohistochemical study will be performed with x40 field counting with photographs and grid (Dako omnis with envision system) for: Macrophages The monitor-glucometer will be recovered for download and study of the record. The interstitial glucose - blood pairs will be made with those recorded but not used for callibration. Glucose sensor values and insulin doses will be recover from tha medical application

Official Title
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Human Subcutaneous infLammatory Response to Glucose Sensors: Impact on the Quality of the Measure

Conditions
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Inflammatory Response to Glucose Sensors

Intervention / Treatment
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* Device: glucose sensor


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1. Type 1 diabetes of more than 6 months duration, confirmed by positivity for Ab antiGAD 65 2. Be a regular user of a continuous glucose monitoring system 2. To Understand the proposed protocol and acceptance of participation. Exclusion Criteria: Treatment with drugs that could potentially modify the inflammatory response during the 10 days prior to surgery (non-steroidal anti-inflammatory drugs or corticosteroids, antioxidants or platelet antiaggregants).

Ages Eligible for Study
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Minimum Age: 18 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Biopsy performed<br>after 10 days of use, the sensor is removed and the biopsy performed | Device: glucose sensor<br>* skin biopsy (punch)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Macrophages sourronding the sensor |  | 10 days | 
| MARD (CGM record for 10 days) | median absolute relative difference (BG- Sensor glucose) | 10 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Enzymatic glucose sensors, foreign body response