The investigators are undertaking a clinical blister model with or without dietary supplementation with omega-3 fatty acids (i.e., Lovaza) to determine the role of specialized pro-resolving mediators - endogenous lipids converted from omega-3 fatty acid precursors including those in Lovaza - on inflammation parameters and their resolution.
The specific aims of this study are based on the hypothesis that in health, natural pro-resolving mechanisms, including specialized pro-resolving mediators and cellular effectors, are generated to promote the resolution of acute inflammation. The specific aims are: Aim 1. Map the formation of specialized pro-resolving mediators and their relationship to acute tissue inflammation Aim 2. Determine the influence of omega-3 fatty acids on the formation and action of pro-resolving mediators during acute inflammation. Medical history and clinical information will be obtained from the participant's health record for study purposes to be sure that participants meet the appropriate inclusion and exclusion criteria. The phlebotomy and topical application of the cantharidin, the imaging and clinical assessment and sampling of blister exudates will be performed by Dr. Katherine Walker or Dr. Joseph Merola and clinical study team at Brigham and Women's Hospital in the Building For Transformative Medicine (3rd floor, 60 Fenwood Road, Boston, MA). The biochemical, immunological and histological analyses will be performed in the laboratories of Drs. Bruce Levy and Charles Serhan at BWH in the Building For Transformative Medicine (3rd floor, 60 Fenwood Road). The intervention protocol will involve simultaneous topical application of 12.5 mcl 0.1% cantharidin to two sites on the volar surface of one forearm. This dose is known to elicit a consistent, safe, localized reaction entailing redness (erythema), mild tenderness and warmth at the site, 2-3 cm in diameter. Subsequently, blister exudative fluid will be removed from each blister site, one during onset phase of inflammation (24 hrs after cantharidin) and the second during resolution phase (72 hrs after cantharidin). The blister exudates will be sampled by piercing the roof of the blister with a sterile needle to collect the exudate at designated time points. The site is disinfected prior to collection of the blister exudate and subsequently protected by a wound dressing after the sample collection step. The intervention protocol will be performed twice for each participant, under 2 distinct conditions: 1. without omega-3 fatty acid supplementation 2. with omega-3 fatty acid supplementation: the participant will take 4 capsules (1gram each) of Lovaza daily at 8pm, starting the evening before blister induction and continuing until the second blister fluid has been removed. This study is a crossover design to evaluate the production of pro-resolving mediators and resolution of experimental inflammation with and without additional omega-3 fatty acid supplementation, and to allow each subject to serve as an internal control by undergoing blister formation in both conditions. In order to reduce the influence of repeated cantharidin blister exposures on the outcome measurements, subjects will be randomized to start with either the Lovaza arm or the non-supplementation arm of the blister protocol.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
19
Lovaza contains ethyl esters of omega-3 fatty acids (EPA and DHA) obtained from the oil of several fish sources.
Cantharone is a clinical blistering agent for topical use to remove warts and molluscum contagiosum. We plan to use the drug to elicit a small skin blister and inflammatory response. This is a well described clinical inflammation research experimental model with multiple publications of its safety and utility in tracking the host inflammatory response.
Subjects will have blood drawn from the antecubital vein for not more than 15mL at each visit.
Brigham and Women's Hospital
Boston, Massachusetts, United States
Specialized Pro-Resolving Mediators in Acute Inflammation
Specialized Pro-Resolving Mediators (SPMs) in a participant's peripheral blood and blister fluid will be extracted and analyzed by targeted metabolo-lipidomics with liquid chromatography - tandem mass spectrometry to identify and quantify SPMs and related bioactive lipid mediators, namely leukotrienes and prostaglandins. Note that these fatty acids and bioactive mediators in blister exudates and peripheral blood will have the same units of measure.
Time frame: 24 hours after blister induction
Inflammatory Cells in Acute Blister Exudates
Blister exudate fluid will be collected for determination of the presence of inflammatory cells by total cell count, and wright-giemsa staining of cytospins. Flow cytometry will be performed to confirm cell identity.
Time frame: Change from 24 to 72 hours after blister induction
Inflammatory Cell Changes During Resolution of Acute Inflammation
Blister exudate fluid will be collected for determination of cell activation by flow cytometry, including SPM receptor expression and indicators of cell death.
Time frame: Change from 24 to 72 hours after blister induction
Peripheral Blood Inflammatory Cells During Acute Inflammation and Resolution
Peripheral blood mononuclear cells will be analyzed by flow cytometry to determine activation markers, including SPM receptor expression.
Time frame: Change from baseline to 24 hours and then to 72 hours after blister induction
Specialized Pro-Resolving Mediator Levels During Resolution of Acute Inflammation
Specialized Pro-Resolving Mediators (SPMs) in a participant's peripheral blood and blister fluid will be extracted and analyzed by targeted metabolo-lipidomics with liquid chromatography - tandem mass spectrometry to identify and quantify SPMs and related bioactive lipid mediators, namely leukotrienes and prostaglandins. Note that these fatty acids and bioactive mediators in blister exudates and peripheral blood will have the same units of measure.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Time frame: Change from 24 hours to 72 hours after blister induction