French protocol for the diagnosis and management of familial Mediterranean fever.

Familial Mediterranean fever is the most common monogenic auto-inflammatory disease in the world. It mainly affects people originating from the Mediterranean region. The mutated gene is MEFV, which codes for pyrin. Transmission is autosomal recessive. Patients present with recurrent attacks of fever since childhood associated with abdominal and/or thoracic pain lasting an average of 2-3days and a biological inflammatory syndrome. Other symptoms include arthralgia or arthritis in large joints such as the knees and ankles, myalgia in the lower limbs and pseudo-erysipelas in the ankles. The most serious complication is inflammatory amyloidosis, which can lead to kidney failure. Treatment is based on colchicine, which helps to prevent flares and the onset of renal amyloidosis. This paper proposes national guidelines for the diagnosis, management and follow-up of familial Mediterranean fever in France, where we estimate there are between 5000 and 10,000 patients with the disease at all stages of life. The diagnosis is suspected on the basis of clinical and anamnestic factors and confirmed by genetic analysis. These guidelines also suggest a "treat-to-target" approach to disease management, particularly in case of suspected colchicine resistance - a very rare situation that should remain a diagnosis of elimination, especially after colchicine compliance has been verified. Two special situations are also addressed in these guidelines: kidney failure and pregnancy.

Further characterization of clinical and laboratory features in VEXAS syndrome: large-scale analysis of a multicentre case series of 116 French patients.

BACKGROUND: A new autoinflammatory syndrome related to somatic mutations of UBA1 was recently described and called VEXAS syndrome ('Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic syndrome'). OBJECTIVES: To describe clinical characteristics, laboratory findings and outcomes of VEXAS syndrome. METHODS: One hundred and sixteen patients with VEXAS syndrome were referred to a French multicentre registry between November 2020 and May 2021. The frequency and median of parameters and vital status, from diagnosis to the end of the follow-up, were recorded. RESULTS: The main clinical features of VEXAS syndrome were found to be skin lesions (83%), noninfectious fever (64%), weight loss (62%), lung involvement (50%), ocular symptoms (39%), relapsing chondritis (36%), venous thrombosis (35%), lymph nodes (34%) and arthralgia (27%). Haematological disease was present in 58 cases (50%): myelodysplastic syndrome (MDS; n = 58) and monoclonal gammopathy of unknown significance (n = 12; all patients with MGUS also have a MDS). UBA1 mutations included p.M41T (45%), p.M41V (30%), p.M41L (18%) and splice mutations (7%). After a median follow-up of 3 years, 18 patients died (15·5%; nine of infection and three due to MDS progression). Unsupervised analysis identified three clusters: cluster 1 (47%; mild-to-moderate disease); cluster 2 (16%; underlying MDS and higher mortality rates); and cluster 3 (37%; constitutional manifestations, higher C-reactive protein levels and less frequent chondritis). The 5-year probability of survival was 84·2% in cluster 1, 50·5% in cluster 2 and 89·6% in cluster 3. The UBA1 p.Met41Leu mutation was associated with a better prognosis. CONCLUSIONS: VEXAS syndrome has a large spectrum of organ manifestations and shows different clinical and prognostic profiles. It also raises a potential impact of the identified UBA1 mutation.

[Periodic fever syndrome associated with mutations in the TNF type 1 receptor gene: A differential diagnosis of familial Mediterranean fever that should not be overlooked in patients of Mediterranean origin]. / Le syndrome de fièvre prolongée associée aux mutations du gène du récepteur au TNF de type 1 : un diagnostic différentiel de la fièvre méditerranéenne familiale à ne pas méconnaître chez les patients d'origine méditerranéenne.

INTRODUCTION: Tumor Necrosis Factor Type 1 Receptor Associated Periodic Syndrome (TRAPS) is a rare autosomal dominant autosomal autoinflammatory disease associated with mutations in the TNF type 1 receptor gene (TNFRSF1A). It is characterized by relatively long recurrent febrile seizures with an average duration of 7 days accompanied by arthralgia, myalgia, and usually a rash. In a patient of Mediterranean origin with recurrent fever, familial Mediterranean fever is the first diagnosis to be suspected by argument of frequency. METHODS: A retrospective observational study was conducted on patients from Mediterranean origin followed for TRAPS and included in the "Juvenile Inflammatory Rheumatism" (JIR) observational cohort in the national French autoinflammatory center. The age of onset of symptoms, age of diagnosis, number of years of wandering and treatments received were collected for each index case. RESULTS: Nine patients from 6 families of Mediterranean origin were included. A molecular diagnosis confirmed TRAPS in all patients. The median age at diagnosis was 26 years, the mean number of years of wandering was 17 years. The diagnosis of FMF was made first in all patients. AA amyloidosis revealed TRAPS in 2 patients. Colchicine was started without any efficacy in all cases. Five patients were treated with interleukin-1 inhibitory biotherapy with 100% efficacy. CONCLUSION: In a patient of Mediterranean origin presenting with recurrent febrile abdominal pain of AA amyloidosis, the first diagnosis to be suspected is FMF. Long relapses, dominant transmission, a non-Mediterranean relative, and the ineffectiveness of colchicine should evoke TRAPS.