Role of CXCR4/CXCL12 Axis on the Control of Humoral Immunity and Auto-immunity in Lupus Patients After Influenza Vaccine Challenge

SLE is a chronic autoimmune disease associated with the production of pathogenic anti-nuclear autoantibodies (ANAs) and characterized by the loss of self tolerance and the overexpression of B cells, leading to a high immunoglobulin production, 90% being autoantibodies.

There have been concerns about the safety of vaccination in patients with autoimmune diseases as it has been hypothesised that stimulation of the immune system via vaccination may lead to an increase in disease activity. Furthermore, SLE patients display a variety of immune dysfunctions which may influence their response to influenza vaccination.

Studies indicate that, although influenza vaccination in SLE may generate autoimmune phenomena, no clinically significant increase in SLE disease activity can be expected. Therefore, influenza vaccination can be considered safe in quiescent SLE, in accordance with previous reviews on this subject

The aim of this study is to evaluate if the level of CXCR4 on leucocytes of patients with SLE could be a good prognostic marker for the efficacy and the safety of influenza vaccine in SLE patients. For that purpose, we will assay in lupus patients the cellular level of CXCR4 before and after administration of influenza vaccine and correlate the expression levels of CXCR4 with: 1) the evolution of clinical and biological signs of autoimmunity and 2) the humoral immune response towards influenza. If influenza vaccine has not been associated so far with increased risk of lupus flare, it is important to determine if patients with elevated leucocytes levels of CXCR4, (due to the impact of this molecule in humoral immunity), are more at risk of vaccine side effects particularly of autoimmune origin.