Pilot Study of Gut Commensals in Antiphospholipid Syndrome

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.

Inclusion Criteria: * 18-70 years of age * One of the following groups below: Group 1a: Persistently positive anti-β2GPI on Coumadin (n: 10) Group 1b: Persistently positive anti-β2GPI not on Coumadin (n: 10) Group 2a: Negative aPL on Coumadin (n: 10) Group 2b: Negative aPL not on Coumadin (n: 10) Persistently positive aβ2GPI will be defined as anti-β2GPI immunoglobulin G (IgG)/IgM/IgA ≥ 40 SGU/SMU at two separate time points at least 12 weeks apart. Negative aPL will be defined as negative Lupus anticoagulant test, aCL IgG/IgM/IgA, and anti-β2GPI IgG/IgM/IgA within 12 months of the study entry. Exclusion Criteria: * Any autoimmune diseases including Rheumatoid Arthritis, Spondylarthropathy, Inflammatory Muscle Disease, and Sarcoidosis * Steroid use greater than 10 mg/d prednisone or equivalent 30 days prior to enrollment * Any immunosuppressive drug use within 3 months prior to screening (mycophenolate mofetil, azathioprine, methotrexate, leflunomide, rituximab, cyclophosphamide, intravenous immunoglobulin, plasmapheresis). * Ongoing chronic infection (viral, bacterial or fungal) including known HIV, Hepatitis B/C * Acute infection receiving any antibiotics within 30 days prior to screening * Acute thrombosis within 2 days prior to screening * Major gastrointestinal surgery less than 5 years prior to enrollment (with the exception of appendectomy) * Any Gastrointestinal bleeding history * Inflammatory Bowel Disease diagnosed by biopsy * Celiac Disease diagnosed by biopsy * Bulimia or anorexia nervosa * Probiotics (greater than estimated 10\^9 cfu or organisms per day) within 30 days prior to enrollment (with the exception of fermented beverages, milks or yogurts). * Morbid obesity (BMI ≥ 40) * Diabetes Mellitus Type I or II on medical therapy * Malignancy within one year prior to screening (with the exception of non-metastatic squamous or basal cell skin carcinomas and cervical carcinoma if received curative surgical treatment) * Known alcohol abuse * Pregnancy