MEFV Gene-Related Enterocolitis Account for Some Cases Diagnosed as Inflammatory Bowel Disease Unclassified

Single Nucleotide Polymorphisms of the MEFV Gene E148Q Are Highly Associated With Disease Phenotype in Crohn's Disease

BACKGROUND

Single nucleotide polymorphisms (SNPs) of the MEFV gene may modify inflammatory bowel disease (IBD) activity. The prevalence of MEFV gene SNPs in IBD patients and their involvement in IBD pathophysiology remains unclear.

METHODS

We analyzed 12 MEFV gene SNPs in peripheral leukocytes of Japanese IBD patients (Crohn's disease [CD]: 69 patients, ulcerative colitis: 32 patients) by polymerase chain reaction using next-generation DNA sequencing and evaluated their prevalence and association with the disease characteristics. Inflammasome activity and mature interleukin (IL)-1β and IL-18 production were evaluated in peripheral blood mononuclear cells obtained from CD patients stimulated with lipopolysaccharides and adenosine triphosphate, and compared between those with and without the E148Q SNP. COL1A1 and HSP47 gene expression was analyzed in CCD-18Co cells costimulated with IL-1β and other inflammatory cytokines.

RESULTS

The prevalence of MEFV gene SNPs in IBD patients was similar to that in the human gene database. E148Q was the most common SNP. Compared with CD patients without E148Q, those with E148Q had a significantly greater frequency of the stricture phenotype, and their peripheral blood mononuclear cells exhibited significantly higher IL-1β and IL-18 levels and higher caspase-1 activity. IL-1β and IL-17A synergistically increased COL1A1 and HSP47 gene expression.

CONCLUSIONS

MEFV gene SNPs, including E148Q, modify the behavior of CD. IL-1β and IL-18 are produced through enhanced caspase-1 activity in monocytes of CD patients with E148Q. IL-1β promotes gene expression of fibrosis-related genes by cooperating with IL-17A in myofibroblasts. Therefore, E148Q might be a disease-modifying gene associated with the fibrostenosis phenotype in CD patients.

High frequency of MEFV disease-causing variants in children with very-early-onset inflammatory bowel disease

BACKGROUND

Biological similarities between inflammatory bowel disease (IBD) and familial Mediterranean fever (FMF) have been described in humans and animal models suggesting a possible common genetic basis. FMF is caused by variants in the MEFV gene which encodes pyrin, an immune regulator. This study aimed to investigate the carrier rate of disease-causing MEFV variants in children of different ethnicities diagnosed with very-early-onset IBD (VEO-IBD).

METHODS

The study included 23 children diagnosed with VEO-IBD who had undergone whole exome sequencing. The exomes were evaluated for MEFV monoallelic and biallelic disease-causing variants and compared to exome sequencing data of 250 probands with suspected monogenic diseases other than IBD.

RESULTS

Of the 23 children diagnosed with VEO-IBD, 12 (52%) were carriers of at least one MEFV disease-causing variant, which was threefold higher than in individuals without IBD. The most frequent variants identified were p.M694V and p.E148Q (42% each). The allelic frequency of MEFV variants was found to be higher across the VEO-IBD group in 13 of 14 ethnicities compared to the control group.

CONCLUSION

The study suggests that disease-causing variants in the MEFV gene should be sought in cases of VEO-IBD. However, the clinical importance of this finding is yet to be defined.

IMPACT

There are biological similarities between inflammatory bowel disease and familial Mediterranean fever, suggesting a possible genetic relationship. Children less than 6 years old clinically diagnosed with inflammatory bowel disease have a threefold higher rate of disease-causing variants in the MEFV gene than controls. Monogenic testing in children with very-early-onset inflammatory bowel disease should include a search for MEFV variants.

Pyrin variant E148Q potentiates inflammasome activation and the effect of pathogenic mutations in cis

OBJECTIVE

The p.E148Q variant in pyrin is present in different populations at a frequency of up to 29%, and has been associated with diseases, including vasculitis and FMF. The pathogenicity of p.E148Q in FMF is unclear, even when observed in cis or in trans to a single, typically recessive, pathogenic mutation. We performed functional validation to determine whether p.E148Q increases the ability of pyrin to form an active inflammasome complex in cell lines.

METHODS

We interrogated the Australian Autoinflammatory Disease RegistrY (AADRY) to find candidate inheritance patterns for the p.E148Q variant in pyrin. Different pyrin variant combinations were tested in HEK293T cells stably expressing the adaptor protein apoptosis-associated speck-like (ASC), which were analysed by flow cytometry to visualize inflammasome formation, with and without stimulation by Clostridioides difficile toxin B (TcdB). Inflammasome-dependent cytokine secretion was also quantified by ELISA of supernatants from THP-1 cells transduced with lentiviral expression vectors.

RESULTS

In AADRY, we observed the p.E148Q allele in individuals with autoinflammatory diseases alone or in conjunction with other pyrin variants. Two FMF families harboured the allele p.E148Q-M694I in cis with dominant heritability. In vitro, p.E148Q pyrin could spontaneously potentiate inflammasome formation, with increased IL-1β and IL-18 secretion. p.E148Q in cis to classical FMF mutations provided significant potentiation of inflammasome formation.

CONCLUSION

The p.E148Q variant in pyrin potentiates inflammasome activation in vitro. In cis, this effect is additive to known pathogenic FMF mutations. In some families, this increased effect could explain why FMF segregates as an apparently dominant disease.

Familial Mediterranean fever in Armenian children with inflammatory bowel disease

Inflammatory bowel disease (IBD) and familial Mediterranean fever (FMF) are inflammatory diseases with complex interactions among genetic, immune, and environmental factors. FMF is a monogenic autoinflammatory disease, characterized by recurrent febrile attacks and polyserositis, and is manifested mainly in childhood. FMF is widespread in Armenia. There are reports on the concurrent occurrence of FMF and IBD. MEFV gene mutations may have a disease-modifying effect on IBD. We have investigated the frequency of MEFV mutations and FMF in Armenian children with IBD and their influence on the clinical course. A total of 69 untreated IBD patients under 18 years of age were enrolled: 52.1% (36) had ulcerative colitis (UC), 21.7% (15) had Crohn's disease (CD), and 26.0% (18) had unclassified colitis (IBD-U). The frequency of FMF among them was 36.2% (25/69), and MEFV mutations were identified in 53.6% (37/69). The highest rate of MEFV mutations and FMF was in UC patients (61.1% and 41.6% respectively). In all, 56.7% (21/37) of IBD patients with MEFV mutations had M694V mutated alleles, mainly in compound heterozygous and heterozygous states. There were no associations in the group of IBD patients with coexisting FMF (25), either between any MEFV mutation and type of IBD or coexistence of FMF. Overall, 36.0% (9/25) of them developed VEO IBD and carried mainly the M694V mutation. We concluded that the carrier frequency of MEFV mutations among Armenian pediatric IBD patients was rather high (53.6%), especially for UC. It was suggested that the MEFV gene is not necessarily a susceptibility gene but most likely modifies the course of IBD. MEFV genetic testing was recommended for Armenian pediatric IBD patients, especially for VEO UC and IBD-U, atypical IBD course, or resistance to the conventional treatment. They should also be asked for isolated febrile attacks, recurrent arthritis, and family history, even in the absence of FMF typical symptoms, to rule out FMF and its complications.

Recurrent Bouts of Fever and Transient Hydrosalpinx Manifested in a Female Carrying MEFV G304R Gene Variant: A Case Report

Familial Mediterranean fever (FMF) is an inherited autoinflammatory disease characterized by recurrent bouts of fever and serositis. Mediterranean Fever (MEFV) gene mutations may cause not just FMF but various serositis including arthritis, enterocolitis, aseptic meningitis, pulmonary disease, and pericarditis. In this report, we present a 44-year-old female carrying MEFV gene variant. She was admitted to our hospital with a high fever, right back pain during inspiration, and lower-left abdominal pain. Laboratory findings showed high inflammatory response. Computed tomography (CT) indicated pleurisy of the right lobe and inflammation of the left uterine appendage. Transvaginal sonography and magnetic resonance imaging (MRI) indicated hydrosalpinx of the left oviduct. The symptoms of recurrent fever and transient serositis suggested FMF, and abdominal pain was resolved after taking colchicine. Later, it turned out that she had MEFV gene mutation (exon2 G304R heterozygous). Although she did not meet the criteria of FMF, this is the first reported MEFV variant carrier with transient hydrosalpinx. Attacks in female patients with FMF are triggered by menstruation. Moreover, FMF and associated amyloidosis may cause both male and female infertility. Although male patients with FMF may present with acute scrotum, diagnostic criteria of FMF do not include inflammation of uterine appendages. Internal medicine physicians need to cooperate with gynecologists to diagnose female patients carrying MEFV gene variants.

Next generation sequencing (NGS)-based approach to diagnosing Algerian patients with suspected inborn errors of immunity (IEIs)

The advent of next-generation sequencing (NGS) technologies has greatly expanded our understanding of both the clinical spectra and genetic landscape of inborn errors of immunity (IEIs). Endogamous populations may be enriched for unique, ancestry-specific disease-causing variants, a consideration that significantly impacts molecular testing and analysis strategies. Herein, we report on the application of a 2-step NGS-based testing approach beginning with targeted gene panels (TGPs) tailored to specific IEI subtypes and reflexing to whole exome sequencing (WES) if negative for Northwest Algerian patients with suspected IEIs. Our overall diagnostic yield of 57% is comparable to others broadly applying short-read NGS to IEI detection, but data from our localized cohort show some similarities and differences from NGS studies performed on larger regional IEI cohorts. This suggests the importance of tailoring diagnostic strategies to local demographics and needs, but also highlights ongoing concerns inherent to the application of genomics for clinical IEI diagnostics.

Possible Association of Mutations in the MEFV Gene with the Intestinal Phenotype of Behçet's Disease and Refractoriness to Treatment

BACKGROUND

Mediterranean fever (MEFV) gene mutations are responsible for familial Mediterranean fever (FMF) and associated with other inflammatory diseases. However, the effects of MEFV gene mutations on intestinal Behçet's disease (BD) are unknown. In this study, we investigated these mutations and clinical features in patients with intestinal BD.

METHODS

MEFV gene analysis was performed in 16 patients with intestinal BD, 10 with BD without intestinal lesions, and 50 healthy controls. Clinical features of patients with intestinal BD were retrospectively assessed.

RESULTS

The rates of MEFV gene mutations in patients with intestinal BD, BD without intestinal lesions, and healthy controls were 75%, 50%, and 38%, respectively. Only 2 of 12 patients with intestinal BD harboring MEFV gene mutations (17%) were controlled without immunosuppressive treatment, while 8 patients (67%) required therapy with tumor necrosis factor (TNF) inhibitors. Among patients with intestinal BD without MEFV gene mutations (four patients), three (75%) were controlled by the administration of 5-aminosalicylic acid with or without colchicine, and one (25%) required TNF inhibitors. All patients who underwent intestinal resection had MEFV gene mutations. Immunohistochemical analysis and in situ hybridization with interleukin-1β (IL-1β) showed a high expression of IL-1β only in injured areas, suggesting that IL-1β may be involved in the formation of ulcers in patients with intestinal BD carrying MEFV gene mutations.

CONCLUSION

Mutations in the MEFV gene may be associated with intestinal lesions of BD and refractoriness to treatment.

A patient with familial Mediterranean fever mimicking diarrhea-dominant irritable bowel syndrome who successfully responded to treatment with colchicine: a case report

Background

Irritable bowel syndrome is a functional gastrointestinal disease. Visceral hypersensitivity is the most important pathophysiology in irritable bowel syndrome. Currently, diagnosis of irritable bowel syndrome is based on symptoms and exclusion of other organic diseases. Although the diagnosis of irritable bowel syndrome can be made based on the Rome IV criteria, one may speculate that complete exclusion of other organic diseases is not so easy, especially in cases uncontrolled with standard therapies.

Case presentation

We present herein a case of familial Mediterranean fever in a young Japanese patient who had been suffering from an irritable bowel syndrome-like clinical course. A 25-year-old Japanese male had been diagnosed as having diarrhea-predominant irritable bowel syndrome 5 years earlier. Unfortunately, standard therapies failed to improve irritable bowel syndrome symptoms. After careful medical history-taking, we understood that he had also experienced periodic fever since 10 years ago. Although no mutation was identified in the Mediterranean fever gene, not only periodic fever but abdominal symptoms improved completely after colchicine administration. He was therefore diagnosed as having familial Mediterranean fever and that the abdominal symptoms may be related to the disease.

Conclusions

Familial Mediterranean fever should be considered as a cause of irritable bowel syndrome-like symptoms.

Advanced endoscopy for the management of inflammatory digestive diseases: Review of the Japan Gastroenterological Endoscopy Society core session

A series of workshops entitled "Advanced endoscopy in the management of inflammatory digestive disease" was held at the 97^th to 100^th biannual meeting of the Japan Gastroenterological Endoscopy Society. During these core sessions, research findings concerning various endoscopic practices in the field of inflammatory bowel disease (IBD) were presented, and meaningful discussions were shared on the evolving role and future challenges of endoscopy in IBD. This article reviews these core sessions and discusses current topics on the role of endoscopy, focusing on the diagnosis, disease monitoring, mucosal healing assessments, cancer surveillance, and therapeutic interventions in IBD.

Clinical and molecular evaluation of MEFV gene variants in the Turkish population: a study by the National Genetics Consortium

Familial Mediterranean fever (FMF) is a monogenic autoinflammatory disorder with recurrent fever, abdominal pain, serositis, articular manifestations, erysipelas-like erythema, and renal complications as its main features. Caused by the mutations in the MEditerranean FeVer (MEFV) gene, it mainly affects people of Mediterranean descent with a higher incidence in the Turkish, Jewish, Arabic, and Armenian populations. As our understanding of FMF improves, it becomes clearer that we are facing with a more complex picture of FMF with respect to its pathogenesis, penetrance, variant type (gain-of-function vs. loss-of-function), and inheritance. In this study, MEFV gene analysis results and clinical findings of 27,504 patients from 35 universities and institutions in Turkey and Northern Cyprus are combined in an effort to provide a better insight into the genotype-phenotype correlation and how a specific variant contributes to certain clinical findings in FMF patients. Our results may help better understand this complex disease and how the genotype may sometimes contribute to phenotype. Unlike many studies in the literature, our study investigated a broader symptomatic spectrum and the relationship between the genotype and phenotype data. In this sense, we aimed to guide all clinicians and academicians who work in this field to better establish a comprehensive data set for the patients. One of the biggest messages of our study is that lack of uniformity in some clinical and demographic data of participants may become an obstacle in approaching FMF patients and understanding this complex disease.

Evaluation of the Clinical Effects and Frequency of MEFV Gene Mutation in Patients with Inflammatory Bowel Disease

Background

The clinical and pathological features of inflammatory bowel disease (IBD) and Familial Mediterranean Fever (FMF) are similar.

Objective

Here, the frequency of Mediterranean Fever (MEFV) gene mutation and its effect on the outcome of IBD were evaluated.

Methods

DNA sequence analysis detected the variants on the MEFV gene in patients with IBD. The relationship between mutations and the need for steroids, immunomodulators, biologics, and surgery was assessed.

Results

We evaluated 100 patients with IBD (55 with ulcerative colitis (UC) and 45 with Crohn's disease (CD)) and 60 healthy individuals as controls. The frequency of MEFV gene mutation was 26.7% (n = 12) and 14.5% (n = 8) for UC and CD, respectively. No relationship was found between MEFV gene mutation and the need for steroids, immunomodulators, and biologics (p = 0.446; p = 0.708; p > 0.999, resp.); however, in UC, the need for surgery in those with mutation (p = 0.018) and E148Q mutation alone was significant (p = 0.037).

Conclusion

The rate of MEFV gene mutations was high in patients with UC who required surgery. These patients have frequent and severe attacks, indicating that the mutations are related to disease severity. MEFV mutation as a modifier factor of IBD should be considered.

Mediterranean fever gene-associated enterocolitis in an elderly Japanese woman

An 86-year-old woman was admitted to our hospital with anemia. She had never experienced symptoms of serositis. Colonoscopy revealed colitis with erosions and a friable mucosa. First, she was diagnosed with unclassified inflammatory bowel disease (IBD-U). We suspected familial Mediterranean fever as a differential diagnosis of IBD-U, and MEFV gene analysis showed heterozygosity for Exon2 R202Q. The patient was treated with colchicine 0.5 mg. After 4 months, a follow-up colonoscopy showed remarkable improvement of the mucosal inflammation throughout the entire colon. MEFV gene-associated enterocolitis responding to colchicine may be observed in patients with IBD-U and elucidating the role of MEFV gene mutations in intestinal inflammation is a future challenge.

Gastrointestinal involvement in a patient with familial Mediterranean fever mimicking Crohn's disease: a case report

Familial Mediterranean fever (FMF) in gastrointestinal involvement has been considered rare, but resent reports suggest that FMF causes enterocolitis which is similar endoscopic findings to inflammatory bowel disease. The clinical characteristics and endoscopic findings of FMF with enterocolitis remain unclear. Here, we report a case of an FMF patient who had enterocolitis with stricture of the terminal ileum whose endoscopic and clinical features mimicked Crohn’s disease. A 23-year-old man who was diagnosed with FMF 10 years ago presented with abdominal pain and diarrhea. Colonoscopy showed terminal ileitis and aphthous colitis; however, these findings, including the histopathology, did not confirm Crohn’s disease. Therefore, we diagnosed FMF with enterocolitis and administered anti-interleukin-1β monoclonal antibody (canakinumab). The patient’s symptoms improved with treatment, but after 1 year, lower abdominal pain recurred. Colonoscopy revealed a stricture of the terminal ileum. Endoscopic balloon dilation relieved his symptoms. At present, he has been followed up without surgical treatment by endoscopic balloon dilation every 6 month. Clinicians should be aware that FMF accompanied with enterocolitis may resemble Crohn’s disease.

Contradictory Effects of NLRP3 Inflammasome Regulatory Mechanisms in Colitis

The inflammasome is an intracellular molecular complex, which is mainly involved in innate immunity. Inflammasomes are formed in response to danger signals, associated with infection and injury, and mainly regulate the secretion of interleukin-1β and interleukin-18. Inflammasome dysregulation is known to be associated with various diseases and conditions, and its regulatory mechanisms have become of great interest in recent years. In the colon, inflammasomes have been reported to be associated with autophagy and the microbiota, and their dysregulation contributes to colitis and. However, the detailed role of inflammasomes in inflammatory bowel disease is still under debate because the mechanisms that regulate the inflammasome are complex and the inflammasome components and cytokines show seemingly contradictory multiple effects. Herein, we comprehensively review the literature on inflammasome functioning in the colon and describe the complex interactions of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome components with inflammatory cytokines, autophagy, and the microbiota in experimental colitis models and patients with inflammatory bowel disease.

Amyloid A amyloidosis in a patient with Caplan's syndrome, with special reference to genetic predisposition

Secondary amyloid A (AA) amyloidosis, which is a disorder of protein conformation and metabolism, is an important serious complication of inflammatory diseases, especially rheumatoid arthritis (RA). AA amyloidosis develops when AA fibrils, which are derived from the acute-phase reactant, serum amyloid AA (SAA) protein, in the circulation, are deposited in organs and cause systemic organ dysfunction. Caplan's syndrome, or rheumatoid pneumoconiosis, is a rare type of lung disease in which individuals suffering from RA develop lung nodules that are associated with occupational exposure to silica and coal dust. Confirmation of diagnosing as Caplan's syndrome requires the patient's occupational history, imaging studies, and serology. A 72-year-old male, working as a tunnel construction worker for 38 years, with RA who had both chronic cardiac and renal dysfunction was referred to our hospital. He received a diagnosis of pneumoconiosis about 20 years ago, after which he was also diagnosed with RA. So far we performed medical English literature searches on the combination of Caplan's syndrome with AA amyloidosis; there were no articles in relation to such association. Although RA is one of the most common underlying diseases that occur with AA amyloidosis, our report here is the first description of a case of Caplan's syndrome associated with AA amyloidosis. In this report, we provide details about this rare disease occurring with AA amyloidosis and discuss on the possible pathogenesis of AA amyloidosis from a genetic point of aetiological view.