The familial Mediterranean fever (MEVF) gene as a modifier of Crohn's disease

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.

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.

The Influence of Coexisting Familial Mediterranean Fever on Crohn's Disease: Data From an FMF Endemic Area

GOAL

The goal of this study was to evaluate the impact of coexisting familial Mediterranean fever (FMF) on Crohn's disease (CD) patients' phenotype and disease course in an endemic region for FMF.

BACKGROUND

CD and FMF are inflammatory diseases characterized by recurrent abdominal pain and fever attacks. The impact of coexisting FMF on CD patients' phenotype and disease course is currently unknown.

MATERIALS AND METHODS

We reviewed the medical records of 210 adult CD patients who were regularly followed up at a tertiary gastroenterology clinic between November 2006 and April 2018. The patients were divided into FMF positive (CD-FMF) and FMF negative (CD-control) groups. The severity of CD was assessed by the rate of hospitalization because of CD, the need for biological therapy, and whether surgery was performed for CD.

RESULTS

Eight (3.8%) of 210 CD patients have concomitant FMF, which is 35 to 40 times higher than expected in an endemic region for FMF. Baseline demographic parameters, location/behavior of the CD, and initial therapeutic regimens were similar between the 2 groups. The prevalence of peripheral arthritis was significantly higher in CD-FMF group (37.5% vs. 10.4%, respectively, P =0.04). A significantly greater proportion of the CD-FMF patients had received biological therapy (50% vs. 11.9%; P =0.012). Steroid dependence and CD-related hospitalization rates in the CD-FMF group were relatively higher but were not statistically significant (37.5% vs. 15.3 and 62.5% vs. 41.1%).

CONCLUSIONS

Our findings indicate that the disease course of CD tends to be more severe in patients with coexisting FMF.

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.

Tripartite motif family proteins in inflammatory bowel disease: Mechanisms and potential for interventions

Inflammatory bowel disease (IBD) is a chronic recurrent gastrointestinal inflammatory disease that poses a heavy burden to the global healthcare system. However, the current paucity of mechanistic understanding of IBD pathogenesis hampers the development of aetiology‐directed therapies. Novel therapeutic options based on IBD pathogenesis are urgently needed for attaining better long‐term prognosis for IBD patients. The tripartite motif (TRIM) family is a large protein family including more than 70 structurally conservative members, typically characterized by their RBCC structure, which primarily function as E3 ubiquitin ligases in post‐translational modification. They have emerged as regulators of a broad range of cellular mechanisms, including proliferation, differentiation, transcription and immune regulation. TRIM family proteins are involved in multiple diseases, such as viral infection, cancer and autoimmune disorders, including inflammatory bowel disease. This review provides a comprehensive perspective on TRIM proteins' involvement in the pathophysiology and progression of IBD, in particular, on intestinal mucosal barriers, gene susceptibility and opportunistic infections, thus providing novel therapeutic targets for this complicated disease. However, the exact mechanisms of TRIM proteins in IBD pathogenesis and IBD‐related carcinogenesis are still unknown, and more studies are warranted to explore potential therapeutic targets of TRIM proteins in IBD.

NOD2 Versus MEFV: Differential Diagnosis of Yao Syndrome and Familial Mediterranean Fever

OBJECTIVES

Yao syndrome (YAOS, OMIM 617321) was formerly designated as nucleotide-binding oligomerization domain-containing protein-2 (NOD2)-associated autoinflammatory disease (NAID). This disorder shares similar clinical phenotypes with hereditary periodic fever syndromes (HPFS). This study aimed to compare YAOS with familial Mediterranean fever (FMF).

METHODS

In this retrospective study, electronic medical records of a case series of YAOS were reviewed and data were analyzed. All patients underwent genetic testing for periodic fever syndrome 6-gene panel.

RESULTS

A total of 6 cases were presented. These patients were initially thought to have MEditerranean FeVer (MEFV)-negative FMF and received treatment with colchicine. They were eventually diagnosed with YAOS. The differences between these diseases were illustrated. In addition, both MEFV and NOD2 mutations were detected in some patients and family members. Patients with carriage of both gene mutations may present with heterogeneous disease expression. A close correlation between phenotypes and genotypes is needed to make a diagnosis.

CONCLUSIONS

YAOS may mimic FMF. Molecular analysis should cover NOD2 whole gene sequencing to help distinguish these diseases. Both NOD2 and MEFV mutations may contribute to disease expression in an individual.

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.

Familial Mediterranean Fever Gene Mutations and Gout as an Auto-Inflammatory Arthropathy

Introduction:

The auto-inflammatory diseases (AID) are a heterogeneous group of multi-system disorders of innate immunity dysregulation. MEFV gene has major role in AID.

Aim:

The aim of this study is to investigate the frequency of MEFV variant alleles in gout patients as an AID and their genotype-phenotype relationship.

Methods:

Total amount of 224 of the healthy people as a control group (113 male and 111 female) and 24 gouty arthritis patients (20 male and 4 female) entered this study. Blood samples screened for the 12 common pathogenic mutations according to manufacturer’s instructions.

Results:

The mean age of patients was 54 years. MTP joint was the most involved joint (91.66%). Mutations were shown in 5 patients (20.83%) that were not different from healthy population (25%). Five patients carry one mutated MEFV allele, E148Q in 4 patients and V726A in 1 patient. Control group showed 25% mutations as E148Q (18.3%), P369S (3.1%), V726A (2.2%), A744S (1.3%) respectively. The most common mutation detected in patients was E148Q (16.66%) and all of them were males. No significant and meaningful associations were detected between the MEFV gene mutations and gouty arthritis patients.

Conclusion:

There was not any correlation between MEFV gene mutations carriage with age, sex, the number of joint involvement and the course of disease in gouty arthritis. MEFV gene mutations were more frequent in men than women, but this is not statistically significant.

Fecal calprotectin in children with familial Mediterranean fever in the attack-free period

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by recurrent episodes of fever and serosal inflammation. The aim of this study was to evaluate fecal calprotectin (FC) in children with FMF during the non-attack period.

METHODS

A retrospective evaluation was made of the data of a total 66 patients diagnosed with FMF in an attack-free period and without amyloidosis or inflammatory bowel disease (IBD). FC level in the FMF patients was compared with that in the patients with IBD and healthy control subjects.

RESULTS

The FMF patients consisted of 37 boys (56.1%) with a mean age of 10.1 ± 3.9 years. Mean FC was 192.5 μg/g (range, 19.5-800 μg/g) in the FMF group, 597.9 μg/g (range, 180-800 μg/g) in the IBD group, and 43.8 μg/g (range, 19.5-144 μg/g) in the control group. The FC level in the children with FMF was higher than in the control group (P < 0.001), and the FC level of the IBD patients was higher than both the FMF and the control groups (P = 0.020, P < 0.001, respectively).

CONCLUSIONS

FC was higher in FMF patients compared with healthy children even in the absence of IBD/amyloidosis. Even though colonoscopy is the gold standard in identifying intestinal inflammation in FMF patients, FC, a non-invasive and inexpensive method, can be used for screening. The presence of subclinical intestinal inflammation was also quantitatively identified in children with FMF.

The influence of carrying MEFV gene variants on juvenile systemic lupus erythematosus

Juvenile-onset systemic lupus erythematosus (jSLE) patients typically have a more severe disease course than adults with SLE. We aimed to assess the prevalence and disease course of jSLE patients carrying MEFV variants. MEFV variant analyses were performed in 44 jSLE patients and effect of these variants on disease severity and course was analyzed by SLEDAI score and SLICC/ACR index. Ten of the patients (22.7%) had a MEFV variant. The median (min-max) SLEDAI score and SLICC/ACR index were 2(0-13) and 0(0-3), respectively. Median age at disease onset, disease duration, SLICC/ACR indexes, SLEDAI scores, clinical and laboratory findings of the patients were comparable in carriers of variants and non-carriers. Nineteen patients (43.2%) had biopsy-proven lupus nephritis and four of these patients had MEFV variants. There was no significant difference between patients with and without MEFV carriers in terms of lupus nephritis. Even though not significant statistically, renal involvement was milder in MEFV carriers than non-carriers. The presence of MEFV variants does not increase the overall susceptibility to jSLE in our cohort, while larger number of patients is required to display the protective role of MEFV variants in jSLE.

Periodic fever syndromes: beyond the single gene paradigm

Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease in Canada and is characterized by a clinical syndrome of episodic inflammatory symptoms. Traditionally, the disease is defined by autosomal recessive inheritance of MEFV gene variants, yet FMF also not uncommonly manifests in individuals with only one identified disease-associated allele. Increasing availability and affordability of gene sequencing has led to the identification of multiple MEFV variants; however, they are often of unknown clinical significance. Variants in other genes affecting overlapping or distinct inflammatory signaling pathways - together with gene-environment interactions including epigenetic modulation - likely underlie the significant genetic and phenotypic heterogeneity seen among patients with this disease. We review recent evidence of the expanding spectrum of FMF genotype and phenotype and suggest that current drug funding schemes restricting biologic agents to patients with homozygous mutations have not kept pace with our biological understanding of the disease.

Autoinflammatory disease with focus on NOD2-associated disease in the era of genomic medicine

Systemic autoinflammatory diseases (SAIDs) represent a spectrum of genetically heterogeneous inflammatory disorders. Some SAID-associated genes are located in chromosome 16, including familial Mediterranean fever gene (MEFV) and nucleotide-binding oligomerization domain 2 [NOD2] gene that are linked to Crohn's disease, Blau syndrome, and Yao syndrome. These disorders share overlapping clinical phenotypes, and genotyping is diagnostically helpful and distinctive. Using next generation sequencing in SAIDs, digenic variants or combinations of more genetic variants in different genes can be detected, and they may be related to the MEFV and NOD2 genes. These variants may contribute to heterogeneous phenotypes in an individual, complicating the diagnosis and therapy. An awareness of the clinical significance of the digenic or combined gene variants is important in the era of genomic medicine.

A Rare Case of Cryopyrin-associated Periodic Syndrome in an Elderly Woman with NLRP3 and MEFV Mutations

We herein report a case of a 75-year-old woman who presented with a low-grade fever, repeated cold-induced urticaria, and painful leg edemas with neutrocytosis. Because her mother also had cold-induced urticaria and her skin lesions histologically showed neutrophilic dermatitis, we suspected that she had familial cold autoinflammatory syndrome, a subtype of cryopyrin-associated periodic syndromes. Sequencing of the NLRP3 and MEFV genes revealed that she carried both the p.A439V missense mutation and p.E148Q homozygous mutation, which is commonly detected in familial Mediterranean fever patients. The administration of colchicine reduced the frequency and severity of her skin rash and leg edema.

Bile acid analogues are activators of pyrin inflammasome

Bile acids are critical metabolites in the gastrointestinal tract and contribute to maintaining intestinal immune homeostasis through cross-talk with the gut microbiota. The conversion of bile acids by the gut microbiome is now recognized as a factor affecting both host metabolism and immune responses, but its physiological roles remain unclear. We conducted a screen for microbiome metabolites that would function as inflammasome activators and herein report the identification of 12-oxo-lithocholic acid (BAA485), a potential microbiome-derived bile acid metabolite. We demonstrate that the more potent analogue 11-oxo-12S-hydroxylithocholic acid methyl ester (BAA473) can induce secretion of interleukin-18 (IL-18) through activation of the inflammasome in both myeloid and intestinal epithelial cells. Using a genome-wide CRISPR screen with compound induced pyroptosis in THP-1 cells, we identified that inflammasome activation by BAA473 is pyrin-dependent (MEFV). To our knowledge, the bile acid analogues BAA485 and BAA473 are the first small molecule activators of the pyrin inflammasome. We surmise that pyrin inflammasome activation through microbiota-modified bile acid metabolites such as BAA473 and BAA485 plays a role in gut microbiota regulated intestinal immune response. The discovery of these two bioactive compounds may help to further unveil the importance of pyrin in gut homeostasis and autoimmune diseases.

Endoscopic findings in patients with familial Mediterranean fever and dyspeptic symptoms

Aim

The aim of the study was to evaluate the clinical, endoscopic, histopathological, laboratory, and imaging findings of patients with familial Mediterranean fever (FMF) presenting with dyspeptic symptoms.

Material and methods

Endoscopy was performed in 28 patients with FMF undergoing colchicine therapy, who presented to our hospital between 2012 and 2014 with abdominal pain, diarrhoea, and dyspeptic complaints. Upper gastrointestinal system endoscopy was performed in all patients; 16 of these underwent colonoscopy. Demographic characteristics, clinical and laboratory data, genetic analysis, imaging data, and endoscopy and colonoscopy findings were evaluated in all patients.

Results

Histopathological analysis of biopsy specimens revealed gastrointestinal pathology in 21 (75%) patients. Upper endoscopy analysis revealed that 14 (50%) patients had antral gastritis (8 Helicobacter pylori (–) antral gastritis and 6 H. pylori (+) chronic active gastritis) and 2 (7%) cases had giardiasis. Four antral gastritis cases had concomitant esophagitis, and 2 patients had widespread ulcers in the terminal ileum. The rest had a normal colonic appearance; however, three patients with normal colonoscopic findings were found to have chronic active colitis on histopathological examination.

Conclusions

In this study, most patients with FMF presenting with dyspeptic complaints had gastrointestinal pathology. Furthermore, there was higher inflammatory bowel disease incidence in these patients.

Genetic epidemiology of familial Mediterranean fever through integrative analysis of whole genome and exome sequences from Middle East and North Africa

Familial Mediterranean fever (FMF), an autosomal recessive and rare autoinflammatory disease is caused by genetic mutations in the MEFV gene and is highly prevalent in the Mediterranean basin. Although the carrier frequency of specific disease variants in the MEFV gene has been reported from isolated studies, a comprehensive view of variants in the Mediterranean region has not been possible due to paucity of data. The recent availability of whole-genome and whole-exome datasets prompted us to study the genetic epidemiology of MEFV variants in the region. We assembled data from 5 datasets encompassing whole-genome and whole-exome datasets for 2115 individuals from multiple subpopulations in the region and also created a compendium for MEFV genetic variants, which were further systematically annotated as per the American College of Medical Genetics and Genomics (ACMG) guidelines. Our analysis points to significant differences in allele frequencies in the subpopulations, and the carrier frequency for MEFV genetic variants in the population to be about 8%. The MEFV gene appears to be under natural selection from our analysis. To the best of our knowledge, this is the most comprehensive study and analysis of population epidemiology of MEFV gene variants in the Middle East and North African populations.

Treatment of Crohn’s disease and familial Mediterranean fever by leukopheresis: Single shot for two targets

Coexistence of Crohn's disease (CD) and familial Mediterranean fever (FMF) is a rare condition and knowledge about this clinical situation is limited with a few case reports in the literature. The treatment of both diseases depends on their individual therapies. However, it is very hard to deal with this coexistence when CD is refractory to standard therapies. Ongoing activity of CD triggers the clinical attacks of FMF and the symptoms like abdominal pain interfere with both disease presentations which can cause problems about diagnostic and therapeutic approach. The main therapeutic agent for FMF is colchicine and diarrhea is the most common side effect of this drug. This side effect also causes problems about management of these diseases when both of them are clinically active. Here we report probably the first case in the literature with coexisting CD and FMF who was successfully treated by leukopheresis since he was refractory to conventional therapies for CD.

Exertional leg pain in familial Mediterranean fever: a manifestation of an underlying enthesopathy and a marker of more severe disease

OBJECTIVE

Exertional leg pain is a characteristic musculoskeletal manifestation of familial Mediterranean fever (FMF). We aimed to define the frequency and characteristics of exertional leg pain in a large cohort of FMF patients and to evaluate for additional signs and symptoms of spondyloarthritis (SpA) in this patient population.

METHODS

FMF patients were allocated into study or control groups based on the presence or absence of exertional leg pain. Randomly selected patients underwent magnetic resonance imaging (MRI) of the ankle as well as plain radiography of the sacroiliac joints.

RESULTS

The prevalence of exertional leg pain among the 170 FMF patients included in the study was 58.2%. Patients with exertional leg pain had significantly more joint attacks (74.7% versus 40.8%; P < 0.0001), fever attacks (35.4% versus 15.5%; P = 0.004), and pleuritis attacks (48.5% versus 29.6%; P = 0.013) as well as more attacks per year. Elevations of inflammation markers were significantly more frequent among the study group (for the erythrocyte sedimentation rate, 44.4% of patients versus 21.1% of patients; P = 0.016) (for the C-reactive protein level, 48.4% of patients versus 31.8% of patients; P = 0.013), and M694V homozygosity was more prevalent among the study group (45.5% versus 21.1%; P = 0.001). Signs compatible with enthesopathy on MRI were observed in 73.5% of patients in the study group and in 33.3% of patients in the control group (P = 0.046). Definite SpA was diagnosed in 41.2% of the patients in the study group compared to none of the controls (P = 0.07) (odds ratio 1.7 [95% confidence interval 1.2-2.3]).

CONCLUSION

Exertional leg pain is a common manifestation of FMF and is a marker of a more severe disease phenotype. Additionally, exertional leg pain is frequently associated with sacroiliitis and an underlying ankle enthesopathy and should therefore be considered a new feature of SpA.

Familial Mediterranean fever gene (MEFV) mutations and disease severity in systemic lupus erythematosus (SLE): implications for the role of the E148Q MEFV allele in inflammation

OBJECTIVE

Observed low prevalence of SLE among familial Mediterranean fever (FMF) patients in several large cohorts suggests a possible protective effect of the MEFV mutations from SLE. In contrast, SLE patient carriers for the common MEFV mutations had rather complex disease expression with an increased frequency of febrile episodes and pleurisy and a decreased renal complication rate. Our aim was to investigate the prevalence of MEFV gene mutations in patients with SLE and their effect on organ involvement in a well-defined group of biopsy-proven SLE nephritis patients.

MATERIAL AND METHOD

The prevalence of four MEFV gene mutations (M694V, M680I, V726A and E148Q) was investigated in 114 SLE patients and effect on disease severity was analyzed in patients with biopsy-proven SLE nephritis.

RESULTS

None of the SLE patients fulfilled the revised Tel-Hashomer criteria. Fourteen of 114 SLE patients (12.2%) were found to carry at least one MEFV mutation. A single patient in the SLE-Nephritis group was compound heterozygous for M694V/M680I mutations and only one patient in the SLE-Mild group was homozygous for E148Q mutation. Carrier frequency was similar to controls in SLE patients (12.2 vs 18.8%, p = 0.34). After the exclusion of the less penetrant E148Q mutation, re-analysis revealed an association between exon 10 mutations and SLE nephritis (p = 0.050, odds ratio (OR) = 4.16, 95% confidence interval (CI) = 1.04-16.6). Carrier rate for the E148Q mutation decreased in the SLE group (controls vs. SLE = 20/186 vs. 3/114, p = 0.08) and E148Q mutation was absent in SLE nephritis (controls vs. SLE nephritis = 20/186 vs. 0/47, p = 0.016, OR = 11.69, 95% CI = 0.69-197.13).

CONCLUSIONS

Carrier rate for the studied MEFV mutations was slightly lower in the SLE group, which is in agreement with previous observations that FMF may confer some protection from SLE. Exon 10 mutations were associated with SLE nephritis after the exclusion of the E148Q mutation. The significance of the E148Q as a disease-causing mutation is controversial, and whether E148Q substitution is a polymorphism generally affecting inflammatory pathways is not addressed in the current literature. In this regard, absence of the E148Q mutation in SLE nephritis may serve as a clue for further investigation into its role as a general modulatory polymorphism for inflammation. This clarification is necessary to conclude whether other more penetrant MEFV gene mutations confer susceptibility to nephritis in SLE.

Auto-inflammatory diseases in ileal pouch patients with NOD2/CARD15 mutations

Pouchitis is common in ulcerative colitis patients undergoing total proctocolectomy with ileal pouch-anal anastomosis, and chronic antibiotic-refractory pouchitis occurs in a subgroup of the patients. Auto-inflammatory diseases are characterized by systemic inflammation, manifesting as periodic fever, rash, arthritis, and serositis. We describe two cases with ulcerative colitis and an ileal pouch, who presented with extra-intestinal manifestations and genetic features atypical for inflammatory bowel disease alone. Case 1 had a spectrum of clinical manifestations including refractory pouchitis, intermittent fevers, polyarthralgia, and pericarditis. Case 2 presented with oral ulcers, migratory oligoarthritis, and periodic papular rash. Genetic testing in both cases revealed mutations of the NOD2/CARD15 gene, including the IVS8⁺¹⁵⁸ mutation commonly detected among patients with NOD2-associated auto-inflammatory disease. Both of the patients demonstrated clinical improvement of these diverse systemic complaints following treatment with immunosuppressive and anti-inflammatory therapies.

Detection of Mediterranean fever gene mutations in Egyptian children with inflammatory bowel disease

AIM

The aim of the current study is to investigate the prevalence of familial Mediterranean fever gene (MEFV) mutations in a cohort of Egyptian children with inflammatory bowel disease (IBD), and to characterize familial Mediterranean fever (FMF)-IBD patients, helping better understanding of IBD pathogenesis.

METHODS

The study enrolled 17 patients with ulcerative colitis (UC), 15 with Crohn's disease(CD), 10 with indeterminate colitis (IC) and 33 healthy children as controls. All cases and controls were tested for 12 FMF gene mutations by reverse hybridization after multiplex polymerase chain reaction amplification and DNA sampling.

RESULTS

Eighty-eight percent of the IBD patients carried the mutations, with Sequence variant V627A being the commonest versus 42.4% of controls. No associations were found between MEFV gene mutations, and phenotypic characteristics of IBD patients.

CONCLUSION

IBD patients, in populations with a high background carrier rate of MEFV variants, should be screened for MEFV gene mutations, especially those diagnosed as indeterminate colitis. Testing larger numbers of healthy Egyptian children for MEFV gene mutation is important to further determine the allele frequency in Egypt.

Ron receptor-dependent gene regulation of Kupffer cells during endotoxemia

BACKGROUND

Ron receptor tyrosine kinase signaling in macrophages, including Kupffer cells and alveolar macrophages, suppresses endotoxin-induced proinflammatory cytokine/chemokine production. Further, we have also identified genes from Ron replete and Ron deplete livers that were differentially expressed during the progression of liver inflammation associated with acute liver failure in mice by microarray analyses. While important genes and signaling pathways have been identified downstream of Ron signaling during progression of inflammation by this approach, the precise role that Ron receptor plays in regulating the transcriptional landscape in macrophages, and particular in isolated Kupffer cells, has still not been investigated.

METHODS

Kupffer cells were isolated from wild-type (TK+/+) and Ron tyrosine kinase deficient (TK-/-) mice. Ex vivo, the cells were treated with lipopolysaccharide (LPS) in the presence or absence of the Ron ligand, hepatocyte growth factor-like protein (HGFL). Microarray and qRT-PCR analyses were utilized to identify alterations in gene expression between genotypes.

RESULTS

Microarray analyses identified genes expressed differentially in TK+/+ and TK-/- Kupffer cells basally as well as after HGFL and LPS treatment. Interestingly, our studies identified Mefv, a gene that codes for the anti-inflammatory protein pyrin, as an HGFL-stimulated Ron-dependent gene. Moreover, lipocalin 2, a proinflammatory gene, which is induced by LPS, was significantly suppressed by HGFL treatment. Microarray results were validated by qRT-PCR studies on Kupffer cells treated with LPS and HGFL.

CONCLUSION

The studies herein suggest a novel mechanism whereby HGFL-induced Ron receptor activation promotes the expression of anti-inflammatory genes while inhibiting genes involved in inflammation with a net effect of diminished inflammation in macrophages.

The association between autoimmunity and pouchitis

: Restorative proctocolectomy with ileal pouch-anal anastomosis is commonly used in the management of ulcerative colitis. Inflammation of the ileal pouch reservoir, or pouchitis, is a common complication of ileal pouch-anal anastomosis that is incompletely understood. Risk factors including nonsmoker status and primary sclerosing cholangitis have been linked with pouchitis development, but the etiopathogenesis of pouchitis remains poorly defined. Pouchitis is more commonly a complication of ileal pouch-anal anastomosis performed in patients with ulcerative colitis, and similar to ulcerative colitis, chronic pouchitis is associated with extraintestinal manifestations and other diseases of immune origin, suggesting overlap in the disease pathogenesis. It is becoming apparent that pouchitis encompasses clinically distinct subtypes based on the response or lack of response to antibiotic therapy. There is also emerging evidence of the role of autoimmunity in a subgroup of patients with pouchitis, including patients with concurrent primary sclerosing cholangitis, seropositivity for immunoglobulin G4, or infiltration of immunoglobulin G4-expressing plasma cells in the pouch mucosa. The identification of underlying autoimmunity may have important clinical implications in the diagnosis, subclassification, and management of pouchitis.

Association between MEFV gene mutations and recurrent aphthous stomatitis in a cohort of Turkish patients

Recurrent aphthous stomatitis (RAS) has a multifactorial etiopathogenesis, an interaction between predisposing factors and/or systemic conditions and immunological components in genetically predisposed subjects. The Mediterranean fever (MEFV) gene has already been identified as being responsible for familial Mediterranean fever. Because the association between MEFV gene mutations and Behçet's disease has been reported before in several studies, we considered that the role of MEFV gene mutations should be studied in patients with RAS, because of the clinical similarities of both diseases. The aim of this study was to explore the frequency and clinical significance of MEFV gene mutations in a cohort of Turkish patients with RAS. The study population comprised 100 unrelated patients with a clinical diagnosis of RAS and 156 healthy controls. Genomic DNA was isolated and genotyped using polymerase chain reaction and restriction fragment length polymorphism for the four MEFV gene mutations (M694V, M680I, V726A and E148Q). There were statistically significant differences of the MEFV gene mutation carrier rates and allele frequencies between RAS patients and healthy controls (P = 0.042, odds ratio [OR] = 1.9, 95% confidence interval [CI] = 1.01-3.41; and P = 0.039, OR = 1.8, 95% CI = 1.02-3.14, respectively). Even if it is not statistically significant, the E148Q allele frequency was higher in patients with RAS than the control group. A statistically significant increased prevalence of MEFV variants in RAS patients was found. This is the first study to report that missense mutations of MEFV is associated with RAS in the Turkish population.

Association of the MEFV gene variations with inflammatory bowel disease in Turkey

BACKGROUND

Association of NOD2 (CARD15) gene mutations with inflammatory bowel diseases (IBD) is well known. We herein aimed to investigate the role of familial Mediterranean fever-associated MEFV variations in IBD patients as additional regional-specific risk factor.

STUDY

One hundred thirty-seven (78 female, 56.9%) IBD patients [62 Crohn's disease (CD), 75 ulcerative colitis (UC)] were enrolled into the study. The diagnosis of all patients was confirmed by colonoscopy, histopathology, and the clinical findings. One hundred one healthy donors' samples were used as healthy controls. All patients were genotyped for the most common E148Q, M608I, M694V, and V726A variations of the MEFV and R702W, G908R, and 1007fs of the NOD2.

RESULTS

The overall MEFV variation frequency was found to be higher in the IBD (25.5%) patients (28% in UC, 22.6% in CD) compared with controls (9.9%, P=0.006). This association was stronger with the penetrant exon 10 variations (M694V, M680I, V726A; odds ratio =4.5, P=0.001). Contribution of M694V was higher compared with the other variations (14.5% in CD, 17.3% in UC and 3% in controls, odds ratio =6.039, 95% confidence intervals, 1.7-20.7, P=0.002). The overall frequency of 3 NOD2 variants in the IBD group was not different from that of controls.

CONCLUSIONS

The results of this study suggest that the MEFV variations may be an additional susceptibility factor for IBD in certain parts of the world where the carrier rate is high, and the genetic background of the IBD patients may show regional changes.

Familial Mediterranean fever gene (MEFV) mutations as a modifier of systemic lupus erythematosus

The objective of this study was to assess the prevalence of the Mediterranean FeVer ( MEFV) gene mutations in systemic lupus erythematosus (SLE) patients and their effect on organ involvement, as well as disease activity and severity. The frequencies of three familial Mediterranean fever-related MEFV gene mutations ( M694V, V726A and E148Q) were investigated in 70 SLE patients. Organ involvement, Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores were correlated with mutation carriage. Eleven of 70 patients (15.7%) were found to carry an MEFV mutation. A single patient harbored two mutations, E148Q and V726A, without overt familial Mediterranean fever while the rest were heterozygous carriers. Four of the 11 carried an M694V mutation, four carried V726A and two carried E148Q. The majority of MEFV mutation carriers were Sephardic while non-carriers were mainly of Ashkenazi origin (72.7% vs. 45.7% and 47.4% vs. 9.1%, respectively, p = 0.02). SLE onset was significantly earlier in MEFV carriers (27.6 ± 9.7 vs. 38.2 ± 15.5 years, in carriers vs. non-carriers, p = 0.02). Hematologic and serologic parameters were comparable among mutation carriers and non-carriers. Febrile episodes were more common among MEFV mutation carriers (45.4% vs. 15.2%, p = 0.035) and there was a trend for excess episodes of pleuritis as well (54.5% vs. 23.7%, p = 0.06 in carriers vs. non-carriers, respectively). The frequency of secondary anti-phospholipid antibody syndrome was equivalent among the groups. Conversely, compound urinary abnormalities and renal failure was not observed among MEFV carriers yet was present in 33.4% and 18.6% of non-carriers ( p = 0.027 and 0.19, respectively). SLICC damage index and SLEDAI activity index did not differ significantly between the groups. MEFV mutation carriage appears to modify the SLE disease phenotype in that it contributes to an excess of inflammatory manifestations such as fever and pleuritis on the one hand, while thwarting more severe renal involvement on the other.

Prevalence of MEFV gene mutations and their clinical correlations in Turkish children with Henoch-Schönlein purpura

AIM

To investigate the frequency of MEFV mutations and their associations with the clinical and laboratory findings in children with Henoch-Schönlein purpura (HSP).

METHODS

One hundred and seven children with HSP were investigated for 12 common MEFV mutations.

RESULTS

Forty-seven patients (43.9%) were found to have one of the MEFV mutations. Eight patients (7.5%) were homozygous for one mutation, 33 (30.8%) were heterozygous for one and six (5.6%) were compound heterozygous for two mutations. There were no age and sex differences between patients with or without mutations. Scrotal involvement was statistically more frequent in patients with mutations. Leucocyte counts, erythrocyte sedimentation rates, serum C-reactive protein (CRP) concentrations, number of patients with increased CRP levels and number of patients with increased immunoglobulin A concentrations were found to be higher in patients with MEFV mutations. p.M694V was the most frequent mutation and was found to have effects on clinical and laboratory findings in children with HSP. Fifteen patients were started on colchicine with the diagnosis of familial Mediterranean fever (FMF).

CONCLUSION

MEFV mutations are more frequent in HSP than in the general population, and mutation carriers may have more severe clinical findings with higher inflammatory response, suggesting a dysregulation of the inflammatory response because of defective gene encoding the protein pyrine. Investigation of these mutations may be beneficial to follow-up the susceptible patients more closely leading to early diagnosis and treatment of FMF.

The association of inflammatory bowel disease and Mediterranean fever gene (MEFV) mutations in Turkish children

BACKGROUND AND AIMS

Familial Mediterranean fever (FMF) and inflammatory bowel disease (IBD) concordance has been investigated in a few studies. We investigated MEFV mutations and prevalence of FMF disease in Turkish children with IBD and their relationship with the disease severity.

METHODS

Sixteen patients with ulcerative colitis (UC), 14 with Crohn's disease (CD) and three with indeterminate colitis (IC) were enrolled in the study (median age 13 years, range 0.6-16 years, n = 19 boys). Demographic, clinical and laboratory characteristics of the patients were evaluated as well as the parameters of disease severity. All patients were screened for 12 common MEFV mutations.

RESULTS

MEFV mutations were detected in 17 of 66 (25.7%) alleles. Seven patients (four patients with CD, two with IC, and one with UC) were also diagnosed as FMF. FMF disease was found in seven of all IBD patients (21.2%) and four of them had CD. M694V was the leading mutation, and as a disease-causing mutation, it was found to be significantly more frequent in CD patients than UC patients (Fisher's exact test P = 0.03). Demographics, laboratory evaluations, growth parameters, extraintestinal manifestations, and treatment with immunosuppressive agents other than steroids were comparable between the patients with and without FMF in most aspects.

CONCLUSIONS

Although this is a small cohort, disease-causing MEFV mutations and FMF disease rate were increased among our patients with IBD. The increase was prominent among CD patients, whereas in UC the rate was similar to the Turkish healthy control population.

Association of familial Mediterranean fever-related MEFV variations with ankylosing spondylitis

OBJECTIVE

The pathogenesis of ankylosing spondylitis (AS) has a strong genetic contribution. Familial Mediterranean fever (FMF) is an autosomal recessively inherited autoinflammatory disorder caused by MEFV gene missense variations, and a clinical association between FMF and AS has been reported previously. The aim of this study was to analyze the association of common MEFV variations (M694V, M680I, V726A, and E148Q) with AS in a group of Turkish patients.

METHODS

The study group comprised 193 patients with AS and 103 matched healthy control subjects. All individuals were genotyped for 4 MEFV variations and HLA-B27 using genomic DNA, and association of the variations with the clinical and laboratory features of the patients was analyzed.

RESULTS

The MEFV missense variations were significantly more frequent in patients with AS (22.3%) compared with healthy control subjects (9.7%; odds ratio [OR] 2.67, 95% confidence interval [95% CI] 1.28-5.56). This difference was more prominent for exon 10 variations (M694V, V726A, M680I) (OR 3.75, 95% CI 1.41-9.97), especially for the most-penetrant variation M694V (OR 4.73, 95% CI 1.39-16.12). MEFV variations were more frequent in HLA-B27-negative patients with AS, and the difference was statistically significant in patients carrying exon 10 variants.

CONCLUSION

FMF-related MEFV variations are associated with AS, and these variations may contribute to the pathogenesis of AS, especially in populations in which the prevalence of FMF is high.

Systemic amyloidosis in inflammatory bowel disease: retrospective study on its prevalence, clinical presentation, and outcome

BACKGROUND

Systemic amyloidosis is a rare but life-threatening complication of inflammatory bowel disease (IBD), most cases being reported among Crohn's disease (CD) patients. The only two available retrospective studies showed a prevalence ranging from 0.9% to 3% among CD patients.

AIMS

To evaluate the prevalence of secondary systemic amyloidosis in a large IBD cohort of a referral centre, and to describe its clinical characteristics and outcome.

METHODS

Patients diagnosed with amyloidosis were identified among 1006 IBD patients included in the IBD database of our centre, and their medical records were carefully reviewed.

RESULTS

Among a total of 1006 IBD patients, 5 cases of amyloidosis were identified, all of them with CD, resulting in a prevalence of 0.5% for IBD and 1% for CD. Two patients died after developing renal failure. Two patients were treated with anti-TNF agents, showing a clinical improvement of their amyloidosis.

CONCLUSIONS

Secondary amyloidosis occurs mainly in long-lasting, complicated, Crohn's disease and seems to be as prevalent among IBD patients as previously reported.

An infant with severe refractory Crohn's disease and homozygous MEFV mutation who dramatically responded to colchicine

Previous studies have suggested that inflammatory bowel disease is particulary frequent and severe in familial Mediterranean fever (FMF) families. An 8-month-old boy was admitted to our hospital with chronic bloody diarrhea, failure to thrive and high-grade fever. He was diagnosed as Crohn's disease (CD) based on clinical, laboratory and histological findings and, corticosteroid therapy was started. The patient did not respond to intensive medical therapy including intravenous corticosteroid, mesalazine, azathioprine, intravenous cyclosporine and enteral feeding. MEFV gene mutation analysis revealed homozygous M694V mutation. In addition to azathioprine and cyclosporine therapy, with the diagnosis of FMF, colchicine therapy was started and partial remission was observed within 2 weeks. To the best of our knowledge, this is the first report of association of CD and FMF in an infant. In cases of CD resistant to medical therapy, possibility of underlying FMF should be considered, especially in countries where FMF is prevalent.

Coexistence of systemic lupus erythematosus and familial Mediterranean fever

Clinical symptoms and findings of familial Mediterranean fever (FMF), occur as a result of autoimmune inflammation of the serous membrane which is also seen in systemic lupus erythematosus (SLE). Difficulties are sometimes encountered in the differential diagnosis of FMF because of similar clinical features with other autoimmune inflammatory diseases, and very rarely it can be seen with SLE. The association of FMF and SLE has been reported in one childhood case in Turkey. As far as we know, there is no report in the adult age group. Here, we present the first FMF and SLE association in an adult and discuss the pertinent literature in Turkey.

Genetic variation in the familial Mediterranean fever gene (MEFV) and risk for Crohn's disease and ulcerative colitis

BACKGROUND AND AIMS

The familial Mediterranean fever (FMF) gene (MEFV) encodes pyrin, a major regulator of the inflammasome platform controlling caspase-1 activation and IL-1beta processing. Pyrin has been shown to interact with the gene product of NLRP3, NALP3/cryopyrin, also an important active member of the inflammasome. The NLRP3 region was recently reported to be associated with Crohn's disease (CD) susceptibility. We therefore sought to evaluate MEFV as an inflammatory bowel disease (IBD) susceptibility gene.

METHODOLOGY AND RESULTS

MEFV colonic mucosal gene expression was significantly increased in experimental colitis mice models (TNBS p<0.0003; DSS p<0.006), in biopsies from CD (p<0.02) and severe ulcerative colitis (UC) patients (p<0.008). Comprehensive genetic screening of the MEFV region in the Belgian exploratory sample set (440 CD trios, 137 UC trios, 239 CD cases, 96 UC cases, and 107 healthy controls) identified SNPs located in the MEFV 5' haplotype block that were significantly associated with UC (rs224217; p = 0.003; A allele frequency: 56% cases, 45% controls), while no CD associations were observed. Sequencing and subsequent genotyping of variants located in this associated haplotype block identified three synonymous variants (D102D/rs224225, G138G/rs224224, A165A/rs224223) and one non-synonymous variant (R202Q/rs224222) located in MEFV exon 2 that were significantly associated with UC (rs224222: p = 0.0005; A allele frequency: 32% in cases, 23% in controls). No consistent associations were observed in additional Canadian (256 CD trios, 91 UC trios) and Scottish (495 UC, 370 controls) sample sets. We note that rs224222 showed marginal association (p = 0.012; G allele frequency: 82% in cases, 70% in controls) in the Canadian sample, but with a different risk allele. None of the NLRP3 common variants were associated with UC in the Belgian-Canadian UC samples and no significant interactions were observed between NLRP3 and MEFV that could explain the observed flip-flop of the rs224222 risk allele.

CONCLUSION

The differences in association levels observed between the sample sets may be a consequence of distinct founder effects or of the relative small sample size of the cohorts evaluated in this study. However, the results suggest that common variants in the MEFV region do not contribute to CD and UC susceptibility.

Common FMF alleles may predispose to development of Behcet's disease with increased risk for venous thrombosis

BACKGROUND

Behcet's disease (BD) is an inflammatory disorder of unknown cause, associated with vasculitis. Arterial or venous thrombosis occurs in about 25% of BD patients. Familial Mediterranean fever (FMF) is another inflammatory disorder, which stems from mutations in the FMF gene (MEFV) and shares a number of features with BD.

OBJECTIVE

MEFV analysis in patients with BD suggests that mutated MEFV may act as a susceptibility gene in BD. We studied the rate and the clinical correlates of MEFV mutations in Israeli BD patients.

METHODS

Included were 54 BD patients who satisfied the International Study Group criteria for BD. All BD patients were genotyped using polymerase chain reaction (PCR) and restriction enzyme analysis for the three most common MEFV mutations (M694V, V726A, and E148Q). The association between BD manifestations and MEFV alleles was analysed.

RESULTS

Twenty-one BD patients were found to carry a single MEFV mutation and three additional patients were compound heterozygotes, a frequency significantly higher than that expected for ethnically matched healthy individuals. There were no statistically significant differences between carriers and non-carriers with respect to gender, frequency of HLA B5 antigen, cutaneous lesions, joint disease, and severity score. However, carriers did experience thrombosis more often [54% vs. 17%, p<0.005, odds ratio (OR) = 6.9, 95% confidence interval (CI) 1.75-26.9] and uveitis less often (20% vs. 40%, p<0.05, OR = 0.2, 95% CI 0.04-0.92).

CONCLUSIONS

MEFV appears to be a susceptibility and modifier gene in BD.

Current perspectives on familial Mediterranean fever

PURPOSE OF REVIEW

The gene responsible for familial Mediterranean Fever (FMF), MEditerranean FeVer (MEFV), was identified two decades ago; however, only recent studies have shed light on its pathogenesis. This review focuses on recent studies that have led us to more fully understand FMF pathogenesis.

RECENT FINDINGS

The vast majority of FMF-associated mutations are located in the B30.2 (SPRY) domain, which functions as a ligand binding or a signal transduction domain, at the carboxy terminus of the protein. As a result, B30.2 mutations may lead to postponed apoptosis and inflammation due to the reduced ability of pyrin to control interleukin-1beta (IL-1beta) activation. Development of AA amyloidosis is rare in FMF patients without amyloidogenic single nucleotide polymorphisms (SNPs) (713T allele) of the SAA1 gene. High macrophage inflammatory protein-1alpha levels during FMF attacks might be responsible for the enhancement of T-cell mediated immunity in FMF. IL-1beta-511 (C/T), IL-1beta+3953 (C/T) and IL-1Ra VNTR polymorphisms were not associated with the development of amyloid in FMF patients.

SUMMARY

Future studies should focus on defining the impact of MEFV and other mutations on the pathological course of FMF, and to understand the exact pathophysiology of those patients who are unresponsive to colchicine, which may help to develop novel therapeutic options for the management and improvement of prognosis.