Myeloid Derived Suppressor Cells in Systemic Lupus Erythematosus

Systemic Lupus Erythematosus (SLE) is a chronic invalidating chronic condition, with potential articular, cutaneous, renal, and neurologic involvement. Its pathophysiology is complex, and involves genetic, environmental and hormonal factors, leading to tolerance rupture. Among regulatory cells, Myeloid Derived Suppressor Cells (MDSCs) have been described as being increased during SLE, furthermore during flares. MDSCs are defined phenotypically as being HLA-DR-CD3-CD19-CD33+CD11b+, and either CD14+ (Monocytic MDSCs), CD15+ (Granulocytic MDSCs), or CD14-CD15- (Early-stage MDSCs). However, data regarding their immunosuppressive properties are conflicting, some studies identifying regulatory properties, while other have demonstrated a pro-inflammatory involvement through the induction of Th17 lymphocytes.

To gain insight into the involvement of MDSC in SLE, both deep phenotypical characterization of MDSC and functional assessment will be performed, as well as immunometabolic characterization. This data will be correlated to the clinical presentation and activity of SLE.

Inclusion criteria

• Active systemic lupus erythematosus (SLEDAI > or = 1)
• Written informed consent

Exclusion criteria

• Chronic or acute infection
• Other active auto-immune condition
• Active cancer
• Age below 18