Systemic Sclerosis and Innate T Cells

Role of Innate T Cells in Physiopathology of Systemic Sclerosis

Innate T cells (ITC) are decreased in systemic sclerosis (SS) and an early lymphocyte innateness has been reported. In the other part, ITC are implicated on inflammatory process, including the IL-33/ST2 axis, which is also involved in ScS endotheliopathy.

Data are however scarce and physiopathological mechanisms have not been assessed to date.

The investigators hypothesize a global lymphocyte innateness in SSc, linked to a chronic ITC stimulation by innate signals leading to ITC exhaustion, and their potential role in endotheliopathy and fibroblast activation in SSc.

Inclusion Criteria:

• SSc according to the 2013 ACR/EULAR 2013 criteria (or the 2001 Leroy's criteria for early SSc)

• Patients with others connective tissue disease:

  • Systemic erythematosus lupus (SLE) according to the 2019 ACR/EULAR criteria
  • Primary Sjögren syndrome (pSS) according to the 2016 ACR/EULAR criteria
  • Rheumatoid arthritis according to the 2010 ACR/EULAR criteria
  • Idiopathic inflammatory myopathy (IIM) according to the 2017 ACR/EULAR criteria

• Healthy subjects from general population without known autoimmune disease or connective tissue disease

• ≥18 years-old

Exclusion Criteria:

• Overlap syndrome (including secondary Sjögren syndrome)
• Weight <55 kgs
• Known primary cell immunodeficiency
• Past of autologous or allogenic hematopoietic stem cell transplantation
• Solid neoplasia or malignant hemopathy in remission for less than 12 months an
• Chemotherapy and/or immune checkpoint inhibitors in the last 12 months
• Systemic retinoids
• Active infection and/or antibiotics in the last 2 weeks
• Known active chronic infection among HIV, HTLV, viral hepatitis, syphilis
• Vaccination in the last 4 weeks
• Subject refusing genetic analysis for the present study
• Pregnancy or breastfeeding