Gut bacteria eyed as hidden trigger in autoimmune clotting disorder

NCT ID NCT01787305

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By invitation only
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Cancelled before anyone took part.

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First seen Sep 15, 2026 · Last updated Sep 16, 2026 · Updated 1 time

Summary

Researchers at Yale University are studying whether certain gut bacteria are linked to the autoantibodies that drive antiphospholipid syndrome, an autoimmune disorder that causes dangerous blood clots. The study follows 16 adults, including patients with the syndrome, people who test positive for anti-beta2-glycoprotein I antibodies, and people without those antibodies who have had a clotting event or are at risk. By comparing stool samples and blood markers over time, the team looks for patterns between specific microbes and the immune cells and antibodies that target the body's own tissues.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

What this could lead to
If researchers find a link between specific gut bacteria and the antibodies behind antiphospholipid syndrome, that could point toward new ways to predict or treat the disorder.
What could go wrong
This is a small observational study of 16 people, so it can only show correlations, not cause and effect. The findings may not apply to other patients or lead to a treatment.

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Study facts

What this study's own registry entry says, in plain language.

Participants

16 people

The number who actually took part.

Started

Feb 2013

Finished

Jan 2017

Lead sponsor

Other sponsor

The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Who is studied

Yale New Haven Hospital and affiliated outpatient clinics Hospital for Special Surgery and affiliated outpatient clinics

Ages

18 to 70 years

Sex

Anyone

Healthy volunteers

Accepted

You do not need to have the condition being studied to take part.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

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

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Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Yale University School of Medicine; Yale-New Haven Hospital

    New Haven, Connecticut, 06511, United States

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