Familial Mediterranean fever (FMF) is the most common auto-inflammatory disease (prevalence: 1-5 / 10,000 inhabitants). It is caused by mutations in the MEFV gene, which encodes variants of the Pyrine inflammasome. Inflammasomes are protein complexes of the innate immunity that produce pro-inflammatory cytokines (interleukin-1β).

In vitro, our preliminary results demonstrated that the activation of the inflammatory pyrine (measured by the concentration of interleukin-1β) by kinase inhibitors is significantly increased in FMF patients compared to healthy subjects. Furthermore, a measurement of cell death gave significant results in differentiating the patients from the controls.

The performance of this functional has been tested, fast and simple diagnostic test on common mutations and wish to assess its characteristics for MEFV mutations.

The investigators hypothesize that this quick and simple functional test can serve as a diagnostic tool for FMF and can quantitatively discriminate against patients with different mutations (genotypes).

Inclusion Criteria:

• Children 4 years of age or older or adults
• Having a clinical picture compatible with an FMF and a previous genetic analysis finding at least one mutation of the MEFV gene pathogenic or possibly pathogenic for the FMF group;
• Newly diagnosed or in the process of follow-up (with no time limit or evolutionary criteria);
• During specific or non-specific treatment of the disease or without treatment;
• For whom a blood test is planned as part of routine care;
• Whose informed non-opposition has been collected (or parental non-opposition in the case of a minor patient);

Exclusion Criteria:

• Person under legal protection or under the protection of justice or any other protective measures;
• Person out of state to express their consent;
• Person in emergency situation, vital or not;
• Known infections with HIV and / or HBV and / or HCV;

This study will involve 80 patients with Familial Mediterranean fever, presenting a previous genetic analysis finding at least one mutation of the MEFV gene, considered pathogenic or possibly pathogenic (60 heterozygotes or complex mutations and 20 homozygotes). The controls will be 80 healthy subjects (French national medical and scientific center (INSERM) and French blood bank (EFS) convention).