Conditions: Rheumatoid Arthritis Psoriatic Arthritis Periodontal Disease
Keywords: rheumatoid arthritis psoriatic arthritis periodontitis microbiota microbiome vancomycin doxycycline T cell Th17
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 178
Healthy volunteers: yes

Brief summary:
Rheumatoid arthritis (RA) is an inflammatory form of arthritis that causes joint pain and damage. RA attacks the lining of the joints (synovium), causing swelling that can result in aching and throbbing, and eventually deformity. Even though there have been many advances in the treatment of RA, psoriatic arthritis (PsA), and other inflammatory arthritis, doctors still do not know what causes this inflammation in joints. It is likely that RA occurs as a result of a complex combination of factors, including a person's genes; lifestyle choices, such as smoking and diet; and things in a person's environment, including bacteria or viruses. This study investigates the hypothesis that bacteria living in a person's mouth and/or intestinal tract are responsible, at least in part, for the development of Rheumatoid Arthritis. The investigators believe that by killing those bacteria with antibiotics, they might be able to understand how the immune system works and, maybe, what causes RA.

Detailed description:
If you would like to participate in this study, we will first ask you several questions regarding the status of your arthritis, the medications you use or have used in the recent past, your social and dietary habits, and your medical and surgical history. If your answers tell us that you are the right patient for our study, we will go over a consent form which describes in more detail how we will study your intestinal and mouth bacteria, the immune cells in your blood and other genes, enzymes and proteins that tell us about your disease status.

If you have Psoriatic Arthritis (PsA) or are healthy with no history of arthritis, and would like to participate in this study, your participation would involve only one or two visits, and no treatment.

If you have Rheumatoid Arthritis (RA), your participation would involve six visits, and you would be randomly assigned to receive treatment with the antibiotic doxycycline, or the antibiotic vancomycin, or no antibiotic treatment.

Arms:
arm 1: Patients with rheumatoid arthritis (RA) meeting inclusion criteria, randomized to receive doxycycline, 100 mg twice a day, for 2 months. arm 2: Patients with rheumatoid arthritis (RA) meeting inclusion criteria, randomized to receive vancomycin, 250 mg four times a day, for 2 weeks arm 3: Patients with rheumatoid arthritis (RA) meeting inclusion criteria, randomized to receive no antibiotic treatment for comparison with Doxycycline- and Vancomycin-treated patients.

Patients with psoriatic arthritis (PsA), to provide baseline samples of oral and intestinal microbiota for comparison with RA patients.

Healthy individuals with no history of arthritis, to provide baseline samples of oral and intestinal microbiota for comparison with RA patients.

Interventions: intervention 1: doxycycline intervention 2: vancomycin
Intervention descriptions: intervention 1: doxycycline - 100 mg twice per day, for 2 months intervention 2: vancomycin, 250 mg four times a day, for 2 weeks

Protocol document: