Default of recruitment

This study will investigate whether inhibitors of the JAK / STAT signaling pathway can increase anti-inflammatory functions of B cells in patients with RA using in vitro and in vivo experiments.

This study will first analyze the effect of inhibitors of the JAK / STAT pathway in vitro on B-cell phenotypes and functions in 30 RA patients and 30 patients with osteoarthritis. It will also study the phenotypes and functions of B cells in RA patients for whom JAK / STAT inhibitor treatment has been prescribed by the patient's usual rheumatologist. The analysis will be done before the start of treatment and 3 months later. The phenotypes of B-cells will be assessed by flow cytometry with intra- and extra-cellular stainings. The functions of B cells will be assessed by their ability to differenciate naïve T cells in coculture.

Inclusion criteria:

• General criteria
• Patient, of 18 and more years old
• Subject affiliated to a social security system
• Subject not being in period of exclusion with regard to another protocol
• Absence of pregnancy in the inclusion (date of the last period, use of a contraceptive method, ß -HCG impulsive person in case of doubt)
• Informed consent
• Criteria of inclusion of the group rheumatoid arthritis (in vitro studies):
• Rheumatoid arthritis, corresponding to the the classification ACR / EULAR 2010 criteria
• Criteria of inclusion of the group arthritis (in vitro studies):
• Spinal degenerative osteoarthritis or degenerative osteoarthritis of the members, according to the clinical and radiological elements.
• Criteria of inclusion of the group rheumatoid arthritis, longitudinal study at the patients treated by JAK / STAT inhibitors :
• Rheumatoid Polyarthritis, corresponding to the classification ACR / EULAR 2010 criteria
• Patient to whom a treatment by inhibitor of the way JAK / STAT was proposed in current care of rheumatoid arthritis.

Exclusion criteria:

• General criteria
• Corticosteroid therapy superior to 10 mg / j
• Drip of corticoids in the previous month
• Pregnant or breast-feeding Patients
• Patient under protection(saving) of justice
• Under guardianship Patient or guardianship
• Current Infection
• Criteria of non-inclusion of the group rheumatoid polyarthritis ( in vitro studies):
• Treatment by immunomodulateur or biotherapics (anti-TNF alpha, tocilizumab, abatacept or rituximab) in the previous year
• Criteria of non-inclusion of the group arthritis ( in vitro studies):
• History of autoimmune disease or néoplasie
• Treatment by immunomodulateur or biotherapics (anti-TNF alpha, tocilizumab, abatacept or rituximab)
• Criteria of non-inclusion of the group rheumatoid arthritis, longitudinal study at the patients treated by JAK / STAT inhibitors :

Treatment by rituximab in the previous year