Gut microbiota alterations are associated with phenotype and genotype in familial Mediterranean fever.

OBJECTIVE: FMF is the most common monogenic autoinflammatory disease associated with MEFV mutations. Disease phenotype and response to treatment vary from one patient to another, despite similar genotype, suggesting the role of environmental factors. The objective of this study was to analyse the gut microbiota of a large cohort of FMF patients in relation to disease characteristics. METHODS: The gut microbiotas of 119 FMF patients and 61 healthy controls were analysed using 16 s rRNA gene sequencing. Associations between bacterial taxa, clinical characteristics, and genotypes were evaluated using multivariable association with linear models (MaAslin2), adjusting on age, sex, genotype, presence of AA amyloidosis (n = 17), hepatopathy (n = 5), colchicine intake, colchicine resistance (n = 27), use of biotherapy (n = 10), CRP levels, and number of daily faeces. Bacterial network structures were also analysed. RESULTS: The gut microbiotas of FMF patients differ from those of controls in having increased pro-inflammatory bacteria, such as the Enterobacter, Klebsiella and Ruminococcus gnavus group. Disease characteristics and resistance to colchicine correlated with homozygous mutations and were associated with specific microbiota alteration. Colchicine treatment was associated with the expansion of anti-inflammatory taxa such as Faecalibacterium and Roseburia, while FMF severity was associated with expansion of the Ruminococcus gnavus group and Paracoccus. Colchicine-resistant patients exhibited an alteration of the bacterial network structure, with decreased intertaxa connectivity. CONCLUSION: The gut microbiota of FMF patients correlates with disease characteristics and severity, with an increase in pro-inflammatory taxa in the most severe patients. This suggests a specific role for the gut microbiota in shaping FMF outcomes and response to treatment.

Diagnostic and therapeutic algorithms for monogenic autoinflammatory diseases presenting with recurrent fevers among adults.

Autoinflammatory diseases (AIDs) are defined as disorders of innate immunity. They were initially defined in contrast to autoimmune diseases because of the lack of involvement of the adaptive immune system and circulating autoantibodies. The four monogenic AIDs first described are called the 'historical' AIDs and include FMF (associated with MEFV mutations), cryopyrinopathies (associated with NLRP3 mutations), TNF receptor-associated periodic syndrome (associated with TNFRSF1A mutations) and mevalonate kinase deficiency (MKD; associated with MVK mutations). In the last 10 years, >50 new monogenic AIDs have been discovered due to genetic advances. The most important discovery for adult patients is VEXAS syndrome associated with somatic UBA1 mutations leading to an AID affecting mostly elderly men. Diagnosis of monogenic AIDs is based on personal and family history and detailed analysis of symptoms associated with febrile attacks in the context of elevated peripheral inflammatory markers. This review proposes a practical approach for the diagnosis of the main monogenic AIDs among adult patients.

Response letter to "Latent class analysis of 216 patients with adult-onset Still's disease" by Sugiyama et al.

Sugiyama et al. recently described in "Latent class analysis of 216 patients with adult-onset Still's disease," baseline characteristics, laboratory tests, treatment, relapse, and death of adult-onset Still's disease (AOSD) patients from a Japanese hospital. They identified two subgroups: Class 1 (n=155) with a younger age and typical symptoms of AOSD and Class 2 (n=61) with older patients and fewer typical symptoms of AOSD. In 2022, VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, an established X-linked disease associated with a somatic mutation in UBA1, is considered as a differential diagnosis for AOSD particularly in elderly. These patients from Class 2 could benefit from more explorations for mild myelodysplasia and VEXAS.

USAID Associated with Myeloid Neoplasm and VEXAS Syndrome: Two Differential Diagnoses of Suspected Adult Onset Still's Disease in Elderly Patients.

BACKGROUND: Patients with solid cancers and hematopoietic malignancy can experience systemic symptoms compatible with adult-onset Still's disease (AOSD). The newly described VEXAS, associated with somatic UBA1 mutations, exhibits an overlap of clinical and/or biological pictures with auto inflammatory signs and myelodysplastic syndrome (MDS). OBJECTIVES: To describe a cohort of patients with signs of undifferentiated systemic autoinflammatory disorder (USAID) concordant with AOSD and MDS/chronic myelomonocytic leukemia (CMML) and the prevalence of VEXAS proposed management and outcome. METHODS: A French multicenter retrospective study from the MINHEMON study group also used for other published works with the support of multidisciplinary and complementary networks of physicians and a control group of 104 MDS/CMML. RESULTS: Twenty-six patients were included with a median age at first signs of USAID of 70.5 years with male predominance (4:1). Five patients met the criteria for confirmed AOSD. The most frequent subtypes were MDS with a blast excess (31%) and MDS with multilineage dysplasia (18%). Seven patients presented with acute myeloid leukemia and twelve died during a median follow-up of 2.5 years. Six out of 18 tested patients displayed a somatic UBA1 mutation concordant with VEXAS, including one woman. High-dose corticosteroids led to a response in 13/16 cases and targeted biological therapy alone or in association in 10/12 patients (anakinra, tocilizumab, and infliximab). Azacytidine resulted in complete or partial response in systemic symptoms for 10/12 (83%) patients including 3 VEXAS. CONCLUSIONS: Systemic form of VEXAS syndrome can mimic AOSD. The suspicion of USAID or AOSD in older males with atypia should prompt an evaluation of underlying MDS and assessment of somatic UBA1 mutation.

AA Amyloidosis Secondary to Primary Immune Deficiency: About 40 Cases Including 2 New French Cases and a Systematic Literature Review.

BACKGROUND: Primary immune deficiencies (PIDs) are a heterogeneous group of disorders resulting from defects in immune system. They lead to increased susceptibility to infections and immune dysregulation. The resulting chronic inflammation can induce long-term complications, including AA amyloidosis (AAA). OBJECTIVES: To present the French cases of PID-related AAA and perform a systematic literature review to determine its main features and predisposing factors. METHODS: A systematic literature review was performed by searching MEDLINE up until 2019. New French cases were identified with the help of the Reference Center for Auto-Inflammatory Diseases and AA Amyloidosis and the Reference Center for Hereditary Immune Deficiencies. RESULTS: Forty patients were identified including 2 new French cases. PIDs were varied: immunoglobulin deficits (n = 30), chronic granulomatous disease (n = 3), hyper-IgM syndrome (n = 3), hereditary complete C4 deficiency (n = 1), leucocyte adhesion deficiency type 1 (n = 1), hyper-IgE syndrome (n = 1), and Chediak-Higashi syndrome (n = 1). The mean age at PID diagnosis was 22.2 ± 16.02 years. Renal involvement was the most common manifestation of AAA (80%). Infections were extremely heterogeneous; bacterial infection with pulmonary involvement was the most frequent. Bronchiectasis was particularly common (52.5%). The delay between the first symptoms of PID and AAA diagnosis was 16.18 ± 7 years. Thirteen concomitant diagnoses were made. Twenty patients died during follow-up. CONCLUSION: AAA is a rare life-threatening complication of PID, especially in cases of long diagnostic and therapeutic delays. Bronchiectasis should be considered as a warning sign of chronic inflammation and increased risk of AAA.