Systemic lupus erythematosus (SLE) is a clinically and genetically heterogeneous autoimmune disease. The etiology of lupus and the contribution of genetic, environmental, infectious and hormonal factors to this phenotype have yet to be elucidated. The most straightforward approach to unravel the molecular pathogenesis of lupus may rely on studies of patients who present with early-onset severe phenotypes. Typically, they have at least one of the following clinical features: childhood onset of severe disease (<5 years), parental consanguinity, and presence of family history for autoimmune diseases in a first-degree relative. These patients account for a small proportion of patients with lupus but they inform considerable knowledge about cellular pathways contributing to this inflammatory phenotype. In recent years with the aid of new sequencing technologies, novel or rare pathogenic variants have been reported in over 30 genes predisposing to SLE and SLE-like diseases. Future studies will likely discover many more genes with private variants associated to lupus-like phenotypes. In addition, genome-wide association studies (GWAS) have identified a number of common alleles (SNPs), which increase the risk of developing lupus in adult age. Discovery of a possible shared immune pathway in SLE patients, either with rare or common variants, can provide important clues to better understand this complex disorder, it’s prognosis and can help guide new therapeutic approaches. The aim of this review is to summarize the current knowledge of the clinical presentation, genetic diagnosis and mechanisms of disease in patents with lupus and lupus-related phenotypes.

The aim of the study was to compare the clinical phenotype of patients with familial Mediterranean fever (FMF)-related AA amyloidosis, according to the age of FMF diagnosis and E148Q genotype. Patients with biopsy-confirmed FMF-related AA amyloidosis were included in the study. Tel-Hashomer criteria were applied in the diagnosis of FMF. All patients had detailed baseline assessment of clinical features, renal functions, genetic testing, histopathological diagnosis of amyloidosis, and treatment received. Multiple comparisons were performed according to the age of diagnosis, disease phenotype, mutation, and mortality. Our study included 169 patients with a diagnosis of AA amyloidosis. There were 101 patients diagnosed with FMF < 18 years of age and 68 patients diagnosed who were ≥18 years of age. The three most common clinical manifestations were fever (84.6%), abdominal pain (71.6%), and arthritis (66.9%). The most common allele among FMF patients was M694V (60.6%), followed by E148Q (21.4%), and M680I (10.3%). The most frequent genotypes were M694V/M694V (45.0%), M694V/E148Q (14.8%), and E148Q/E148Q (11.2%) among 169 patients in our cohort. During the follow-up period, 15 patients (10 male, 5 female) died, of whom 14 had M694V homozygous genotype and one was homozygous for E148Q. Clinicians should be aware of patients with homozygous E148Q genotype for close monitoring and further evaluation. The possible relationship between E148Q and AA amyloidosis needs to be confirmed in other ethnicities.

Paediatric Rheumatology; Authors: M. Romano, V. Gerloni, O. De Lucia, D. Piskin, T. Giani, M. Gattinara, M.O. Borghi, C. Bodio, M. Mahler, P.L. Meroni, R. Cimaz

Cardiovascular disease (CVD) remains underestimated in familial Mediterranean fever-associated AA amyloidosis (FMF-AA). We aimed to compare early markers of endothelial dysfunction and atherosclerosis in FMF-AA with a homozygous M694V mutation (Group 1 = 76 patients) in the Mediterranean fever (MEFV) gene and in patients with other genotypes (Group 2 = 93 patients). Measures of increased risk for future CVD events and endothelial dysfunction, including flow-mediated dilatation (FMD), pentraxin-3 (PTX3), and carotid intima-media thickness (cIMT), and fibroblast growth factor 23 (FGF23) as a marker of atherosclerotic vascular disease were compared between groups. The frequency of clinical FMF manifestations did not differ between the two groups apart from arthritis (76.3% in Group 1 and 59.1% in Group 2, p < 0.05). FMD was significantly lower in Group 1 when compared with Group 2 (MD [95% CI]: −0.6 [(−0.89)–(−0.31)]). cIMT, FGF23, and PTX3 levels were higher in Group 1 (cIMT MD [95% CI]: 0.12 [0.08–0.16]; FGF23 MD [95% CI]: 12.8 [5.9–19.6]; PTX3 MD [95% CI]: 13.3 [8.9–17.5]). In patients with FMF-AA, M694V homozygosity is associated with lower FMD values and higher cIMT, FGF23, and PTX3 levels, suggesting increased CVD risk profiles. These data suggest that a genotype–phenotype association exists in terms of endothelial dysfunction and atherosclerosis in patients with FMF-AA.