Systemic Lupus Erythematosus and Accelerated Aging

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease characterized by a breakdown of tolerance against nuclear antigens. Thanks to improvements during the last decades in diagnosis, therapeutics and medical care, the lifespan of SLE patients has remarkably increased. However, standardized mortality ratio are still high in this population, with an increased mortality and morbidity associated with cardiovascular events and infectious events. Interestingly, these conditions are more commonly found during old age in the general population, raising the question of the presence of an acceleration of the aging process in SLE patients.

It has been demonstrated that the aging of the immune system, i.e. immunosenescence, is a key player in the development of many age-related diseases. The acceleration of immunosenescence, as it is observed during chronic viral infections for example, could favor the premature occurrence of clinical manifestations of accelerated aging. The exact contribution of such phenomenon in the context of SLE has, so far, never been explored.

Here, the investigators propose to perform a comprehensive study of the phenomena of immune system aging in patients with SLE in comparison to age-matched healthy controls.

The study will recruit 50 SLE patients followed in Bordeaux University Hospital. Among classical disease activity information, blood samples will be collected at study visit to extensively evaluate immune system aging. Fundamental research will be realized on patients' samples. Patients will be included within their usual follow-up. No extra visit will be needed, and blood samples will be drawn at the same time as those drawn for clinical purposes.

• Absolute numbers of terminally differentiated T lymphocytes [Time frame: At baseline (Day 0)]
• Percentages of terminally differentiated T lymphocytes among total lymphocytes [Time frame: At baseline (Day 0)]
• Percentages of senescent lymphocytes among total lymphocytes [Time frame: At baseline (Day 0)]
• Telomere length in sorted CD4+ and CD8+ T lymphocytes subsets (naïve and memory) [Time frame: At baseline (Day 0)]
• Frequency and phenotype of ELA-specific CD8+ T-cells after 10 days of in vitro priming [Time frame: At baseline (Day 0)]
• Number of naïve T lymphocytes newly produced by thymus evaluated by T-cell receptor excision circles (TRECs) measurement [Time frame: At baseline (Day 0)]
• Concentrations of senescence-associated secretory phenotype (SASP) markers in patients sera [Time frame: At baseline (Day 0)]
• Presence or absence of anti-type I interferons autoantibodies in patients sera [Time frame: At baseline (Day 0)]
• Measurement of disease activity according to Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) [Time frame: At baseline (Day 0)]
• Measurement of disease activity according to British Lupus Assessment Group Index 2004 (BILAG-2004) [Time frame: At baseline (Day 0)]
• Quantification of organ damage according to SLICC/ACR Damage Index [Time frame: At baseline (Day 0)]
• Levels of anti-double stranded DNA in patients sera [Time frame: At baseline (Day 0)]