Pilot Study of Gut Commensals in Antiphospholipid Syndrome

Overview

The purpose of this study is to explore if certain commensals within the gut microbiota (the collection of all microbes that live inside the gut) correlate with autoantibodies in the autoimmune clotting disorder called antiphospholipid syndrome. The study hypothesis is that particular commensals induce the autoantibodies (immune molecules that bind to self structures) and thus correlate with the level of immune cells and antibodies that are self-reactive. Participants are patients with antiphospholipid syndrome and individuals who have tested positive on a prior blood test for anti-beta2-glycoprotein I antibodies or those that have tested negative for antiphospholipid antibodies in their blood, but had a clotting event or a health problem that puts them at risk to form blood clots.

Antiphospholipid syndrome (APS) is an autoimmune disorder in which people are at risk to form blood clots. Having a positive antiphospholipid antibody (aPL) test does not mean the person has APS; but a small number of people do develop APS. These antibodies can also occur in otherwise healthy people. We believe certain bacteria in the gut may cause these antibodies to be produced. Current treatments in APS target the blood clotting system and the goal is to prevent future blood clots. Many patients require this therapy for their entire life. If an persistent trigger can be found within the gut microbiota, it may help in developing other treatments. This study is being conducted at two centers, Yale University School of Medicine in New Haven, CT, and The Hospital for Special Surgery in Manhattan, New York. We expect to enroll a total of 40 subjects in this study at these study sites. Visits will be as follows: Visit 1: Initial screening visit: Review of medical records and questionnaire completion. Visit 2 (one month after initial visit) \& Visit 3 (2 months after initial visit): Questionnaire relating to any changes that may have taken place since recruitment. Brief physical examination by the study doctor. Overall participation: Over a period of 8 weeks. Sample Collection: At each study visit, a sample of blood will be obtained (approximately 6.5 tablespoons of whole blood) via one needle stick. A take-home stool sample collection kit will be provided. Stool samples will be obtained within 24 hours before or after blood collection and delivered (or mailed) to a study site. 2 kits will be provided at the initial visit, 1 kit will be provided at the follow up visit at month 1.