GADD34 (Growth Arrest and DNA Damage inducible-protein) is a regulatory subunit of PP1 (phosphatase 1) phosphatase which dephosphorylates eIF2alpha (eucaryotic initiation factor 2 alpha subunit), representing a negative feedback loop of the unfolded protein response (UPR). Moreover, GADD34 is necessary for type I interferon (IFN) production in response to viral infection in murine models. We investigate here the expression of GADD34 in systemic lupus erythematosus (SLE), in which type I IFN has an important pathogenic role.

We report a case-control study on GADD34 gene expression in PBMC (peripheral blood mononuclear cells) of SLE patients (n=60) and age- and sex-matched healthy controls (n=30). The level of GADD34 gene expression, as well as of type-I IFN response genes in PBMC is measured by quantitative PCR.

Inclusion Criteria:

• Man and woman over 18 years old.
• Patients suffering from SLE (SLICC criteria)
• Patients having given their "Non-opposition"
• Patients with social security affiliation (required in France)

Exclusion Criteria:

• Patients suffering from other auto-immune disease (except SAPL, thyroiditis, and Gougerot Sjogren syndrome)
• Patients with viral infection within 15 days
• People with special protection (defined in articles L1121-§5-8 and articles L3212-§1-3 of French health care law)

Patients suffering from systemic lupus erythematosus