Genome sequencing unveils mutational landscape of the familial Mediterranean fever: Potential implications of IL33/ST2 signalling

Evaluation of periodontal status and cytokine response in children with familial Mediterranean fever or systemic juvenile idiopathic arthritis

OBJECTIVES

Familial Mediterranean fever (FMF) and systemic juvenile idiopathic arthritis (sJIA) are chronic inflammatory diseases and anti-inflammatory agents are used in their treatment. This study evaluates the periodontal status and cytokine response in pediatric patients with FMF or sJIA.

MATERIALS AND METHODS

Forty-eight FMF/sJIA patients were under treatment/control and in attack-free period; 20 systemically healthy children participated in the study. FMF/sJIA patients were divided into two subgroups based on the treatment they received: receiving anti-IL-1 therapy (anti-IL-1 ( +)) and not receiving anti-IL-1 therapy (anti-IL-1 ( -)). The clinical periodontal indices were recorded. Gingival crevicular fluid (GCF) and serum samples were collected. Cytokine levels (IL-1β, IL-1α, TNF-α, IL-6, IL-8, IL-10, IL-17, IL-33) in GCF and serum were measured using ELISA kits.

RESULTS

There was no significant difference between the groups in terms of GCF IL-1β and IL-1α levels although, BoP and GI were significantly lower in the anti-IL-1 ( +) group compared to the control group. GCF IL-10 level was higher in the anti-IL-1 ( -) group than in the control group; GCF IL-8 levels were lower in both FMF/sJIA subgroups versus controls. There was no significant difference between serum cytokine levels of FMF/sJIA subgroups.

CONCLUSIONS

Considering the significant decrease in GI, BoP, and GCF IL-8 levels in the anti-IL-1 ( +) group, it can be concluded that anti-IL-1 medications may suppress periodontal inflammation clinically and immunologically.

CLINICAL RELEVANCE

Anti-IL agents are not currently used in periodontal therapy. However, this study demonstrated the positive effect of anti-IL-1 medications on periodontal inflammation in pediatric patients with FMF or sJIA.

Genotype-phenotype associations in familial Mediterranean fever: a study of 500 Egyptian pediatric patients

INTRODUCTION

Familial Mediterranean fever (FMF) is the most prevalent monogenic autoinflammatory disease, caused by recessively inherited MEFV gene mutations. The most frequent MEFV mutations differ in penetrance and disease severity. We investigated the genotype-phenotype associations of the three most frequent MEFV gene mutations (M680I, M694V, and V726A) in Egyptian FMF children, regarding clinical features, severity, and colchicine response.

METHODS

We conducted a retrospective analysis of the medical registries of 500 FMF pediatric patients from Metropolitan Cairo between 2010 and 2015. The diagnosis was based on the Tel-Hashomer clinical diagnostic criteria. Clinical data and baseline investigations were collected. Mutation analysis was performed by the amplification-refractory mutation system (ARMS)-PCR method.

RESULTS

Males represented 54% and ages ranged from 2 to 18 years. The most frequent symptoms were abdominal pain, fever, and arthralgia. Clinical features mostly associated with M694V mutation either homozygous or heterozygous whether simple, double, or triple. Of the patients, 94.6% completely responded to colchicine. Among patients benefiting from colchicine, 42.5% had M694V/V726A, 21.6% had M694V/V726A/M680I, and 21.1% had M694V genotype. Simple heterozygous M694V or V726A mutations conveyed a moderate phenotype in 57.1% and 50% of cases, respectively. Homozygous M694V mutation showed moderate and severe phenotypes in 21.7% and 65.2% of cases, respectively. Compound M694V/V726A mutation associated with moderate or severe disease in 48.3% and 33.8% of cases, respectively.

CONCLUSION

This study encompasses the largest group of Egyptian pediatric FMF up to date to explore their genotype-phenotype associations. Our results support the notion that the genotype influences the phenotype as regards clinical manifestations, disease severity, and colchicine response.

KEY POINTS

• This study encompasses the largest group of Egyptian pediatric patients affected by FMF up to date to explore their genotype-phenotype associations. • Our results support the notion that the genotype influences the phenotype as regards the clinical manifestations, the disease severity, and the response to colchicine treatment.

Expression and significance of inflammatory reactions mediated by the IL-33/ST2 signaling pathway in the serum of heart failure patients

OBJECTIVE

This research aimed to explore the clinical significance of inflammatory reactions mediated by the IL-33/ST2 signaling pathway in heart failure (HF) patients.

METHODS

A total of 100 HF patients treated in the Department of Cardiology in our hospital were prospectively regarded as the observation group, and 100 healthy age and gender matched patients who were undergoing physical examination were considered as the control group. The levels of interleukin-33 (IL-33), ST2, tumor necrosis factor-α (TNF-α) and pro B-type natriuretic peptide (pro-BNP) in the peripheral blood of patients were detected. The potential correlation between IL-33 and ST2, TNF-α and pro-BNP was analyzed by Pearson.

RESULTS

The levels of IL-33, IL-10, ST2 and pro-BNP in the peripheral blood of patients in the observation group were higher than those in the control group; and they increased with the rise of cardiac function grade (all P<0.05). In addition, IL-33 was positively correlated with TNF-α, ST2 and pro-BNP (r=0.863, 0.879, 0.945; all P<0.05). Multivariate Logistic analysis revealed that the increase of IL-33 and ST2 were independent risk factors of HF.

CONCLUSION

The IL-33 and ST2 levels in the peripheral serum of HF patients are correlated with TNF-α and BNP, the finding of which can assist in clinical diagnosis and treatment.

Update in familial Mediterranean fever

PURPOSE OF REVIEW

Familial Mediterranean fever (FMF) is the prototypic autoinflammatory disease. Although the gene associated with the disease was identified 24 years ago, we still have to learn about the pathogenesis of its inflammation and the variation in the phenotype. In this review, we discuss some recent findings in FMF, such as changes in our understanding of the genetics, aims to define new criteria, and factors contributing to the disease presentation.

RECENT FINDINGS

We finally have learned why a mutation causing this disease was selected in ancient times; MEFV gene mutations confer resistance to the microbe of plague. A group of experts have outlined recommendations for the analysis of the genetics of FMF. These recommendations complement the new classification criteria, which includes genetic results. In the past year, a number of studies have addressed the contributing factors to the inflammation caused by the mutations in pyrin; this has included epigenetic studies as well. Finally, we have long-term data for the use of anti-IL1 treatment in colchicine-resistant patients.

SUMMARY

We now have recommendations for assessing genetic analysis of the MEFV gene and how to reliably classify a patient as FMF. We await further data to understand the contributing genetic and environmental factors that affect the inflammation and final phenotype in FMF and the extent of the disease presentation.

Genome sequencing unveils mutational landscape of the familial Mediterranean fever: Potential implications of IL33/ST2 signalling

Familial Mediterranean fever (FMF) is the most common auto-inflammatory disease. It is transmitted as autosomal recessive trait with mutations in MEditerranean FeVer (MEFV) gene. Despite a typical clinical expression, many patients have either a single or no mutation in MEFV. The current work is aimed to revisit the genetic landscape of FMF disease using high-coverage whole genome sequencing. In atypical patients (carrying a single or no mutation in MEFV), we revealed many rare variants in genes associated with auto-inflammatory disorders, and more interestingly, we discovered a novel variant ( a 2.1-Kb deletion) in exon 11 of IL1RL1 gene, present only in patients. To validate and screen this patient-specific variant, a tandem of allele-specific PCR and quantitative real-time PCR was performed in 184 FMF patients and 218 healthy controls and we demonstrated that the novel deletion was absent in controls and was present in more than 19% of patients. This study sheds more light on the mutational landscape of FMF. Our discovery of a disease-specific variant in IL1RL1 gene may constitute a novel genetic marker for FMF. This finding suggesting a potential role of the IL33/ST2 signalling in the disease pathogenicity highlights a new paradigm in FMF pathophysiology.