Genotype-phenotype correlation in Japanese patients with familial Mediterranean fever: differences in genotype and clinical features between Japanese and Mediterranean populations

A patient with P369S/R408Q variants in the MEFV gene presented with clinical features of Kikuchi disease and Mollaret meningitis, successfully treated with colchicine

BACKGROUND

This case report presents the case of a patient with P369S and R408Q variants in the MEFV gene who exhibited clinical features of Kikuchi disease and Mollaret meningitis. Furthermore, it discusses colchicine as a new potential treatment option for Kikuchi disease-associated meningitis.

CASE PRESENTATION

A 41-year-old Japanese woman presented with fever and headache. She had nuchal rigidity and bilateral cervical lymphadenopathies. Her past medical history included multiple episodes of aseptic meningitis and cervical lymphadenopathy for more than twenty years. Lumbar puncture showed increased lymphocytes and IL-6 level and pathognomonic Mollaret cells. Excisional lymph node biopsy revealed histiocytic necrotizing lymphadenitis, confirming the diagnosis of Kikuchi disease. Subsequently, her recurrent Kikuchi disease and meningitis were successfully treated with colchicine. Furthermore, genetic analysis of the MEFV gene revealed heterozygous P369S/R408Q variants in exon 3.

CONCLUSION

Mollaret meningitis can be associated with Kikuchi disease, and recurrence of both conditions may be suppressed by colchicine when these two coexist.

Elderly-onset familial Mediterranean Fever Carrying MEFV Exon 10 Variants in a Japanese Patient: A Case Report

Familial Mediterranean fever (FMF) is the most prevalent hereditary autoinflammatory disease and is caused by the MEFV gene. In patients carrying MEFV exon 10 variants, FMF usually develops at an early age. A 76-year-old Japanese man presented with a periodic fever lasting 2-3 days, chest pain, and abdominal pain. An MEFV gene analysis revealed compoundheterozygous M694I/E148Q/L110P. Colchicine treatment (0.5 mg/day) improved the patient's symptoms. This is the first case report of an elderly Japanese patient with FMF onset in the 70s carrying the MEFV exon 10 variant.

The significance of carrying MEFV variants in symptomatic and asymptomatic individuals

Familial Mediterranean fever (FMF) is an autoinflammatory disease characterized by recurrent attacks of fever, serositis (peritonitis, pleuritis, or synovitis), and erysipelas-like erythema. Genetic variants in the MEFV gene are associated with this disease. Familial Mediterranean fever is considered an autosomal recessive disease. However, in Middle Eastern countries, a third of the patients expressing FMF manifestations, carry a single mutation only. Moreover, some cases of pure dominant inheritance linked to specific single MEFV variants have also been described. This complex inheritance of MEFV-associated inflammatory diseases poses a serious challenge when interpreting the results of genetic testing in patients having recurrent fever syndromes. In addition, in certain situations, asymptomatic individuals may be incidentally found to carry MEFV variants. These cases pose the question of their exact diagnosis and whether they should be treated. Previous studies have focused on genetic results interpretations among symptomatic patients. In the current article, we would like to elaborate on the genetic interpretation in cases of symptomatic individuals suspected to have FMF and on asymptomatic individuals carrying MEFV variants. We aim to assist physicians unfamiliar with FMF to cope with genetic results interpretation when facing symptomatic and asymptomatic individuals carrying MEFV variants and suggest a management plan accordingly.

Impact of multiple MEFV variants of unknown significance on the diagnosis and clinical presentation of familial Mediterranean fever

The detection of variants of unknown significance (VUS) in familial Mediterranean fever (FMF) is common; however, their diagnostic value remains elusive, and the interpretation of multiple VUS remains difficult. Therefore, we examined FMF diagnosis-associated factors 1-year post-genetic testing in patients with only VUS and assessed the impact of multiple VUS on diagnosis and clinical features. A 1-year follow-up was conducted on patients clinically suspected of having FMF without confirmatory diagnosis owing to the presence of only VUS. Clinical features were compared between patients with a single VUS and those with multiple VUS among patients diagnosed with FMF. Among 261 patients followed up, 202 were diagnosed with FMF based on clinical judgment. No specific clinical symptoms or variant patterns at genetic testing were associated with diagnosis at 1 year. Multiple VUS was significantly and independently associated with a lower response to colchicine than single VUS among patients diagnosed with FMF. However, clinical symptoms showed no correlation with the number of VUS. In conclusion, predicting FMF diagnosis 1-year post-genetic testing in patients with only VUS remains challenging. Moreover, the impact of multiple VUS on FMF may be limited owing to the lack of correlation with clinical features, except colchicine response.

New and future perspectives in familial Mediterranean fever and other autoinflammatory diseases

Systemic autoinflammatory diseases are a group of disorders characterized by sterile episodes of inflammation resulting from defects in the innate immune system. In contrast to classical autoimmune diseases, where circulating autoantibodies and the adaptive immune system are involved, these conditions involve excessive presence of proinflammatory cytokines leading to inflammatory attacks. Excessive cytokine production, functional mutations in regulatory pathways, excessive interferon production, defects in the nuclear factor-kappa B signaling pathway, abnorARCHmal protein folding, and complement activation are the mechanisms leading to autoinflammatory diseases. A defect in the mTOR pathway and trained immunity are newly discovered possible causes in pathogenesis. Early onset and severe forms of classical rheumatological diseases have been more frequently associated with autoinflammatory diseases in the last decade. Therefore, monogenic autoinflammatory diseases should be considered in rheumatic diseases with family history, consanguinity, early onset, and severe disease. The combination of functional and genotyping research will help to identify unclassified patients. The optimal treatment strategy remains uncertain, functional studies such as interferon signature and cytokine profiling, may prove valuable in guiding the treatment process. Stem cell transplantation strategies in autoinflammatory diseases with partial response to biological therapies can be considered. Autoinflammatory diseases are becoming increasingly complex and are bringing new perspectives to already known rheumatic diseases. Although we have effective treatments, we are still far from personalized recommendations.

Molecular analyses of MEFV gene mutation variants in Turkish population

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disease primarily affecting individuals of Turkish, Armenian, Arab, and non-Ashkenazi Jewish descent, caused by mutations in the MEFV gene. The aim of this study was to review the common genotype distributions of MEFV variants and mutations in the Turkish population and evaluate rare mutations.

METHODS AND RESULTS

The study included 2984 patients who applied to Ankara University Ibni Sina Hospital Immunology Laboratory with clinical suspicion of FMF between 2004 and 2014. The data of patients from different regions of the country who were followed up in the immunology-rheumatology clinic with clinical suspicion and presumptive diagnosis of FMF were evaluated retrospectively. Patients were tested for all mutations in Exon 2 and Exon 10, including M694V, M680I, M694I, V726A, E148Q and R202Q. There were 2504 patients with FMF variant. According to genotyping, R202Q (n = 1567, 39.2%) was the most common mutation. The most common co-variant was the R202Q/M694V genotype (n = 507, 16.98%). Allele frequencies for MEFV mutations were as follows: R202Q (n = 1567, 39.2%), M694V (n = 1004, 25.1%), E148Q (n = 463, 11.5%), M680I (n = 354, 8.8%), V726A (n = 319, 7.9%), A744S (n = 51, 1.2%), R761H (N = 41, 1.0%), P706P (N = 25, 0.6%), E167D (N = 23, 0.5%), M694I (N = 23, 0.5%), and K695R (N = 20, 0.5%).

CONCLUSION

This research revealed the prevalence of both common and rare MEFV gene mutations in Turkish FMF patients in various age groups. R202Q was the most prevalent mutation.

Variables for differential diagnosis of familial Mediterranean fever: Multiple correspondence analysis of a large Japanese cohort

OBJECTIVES

We investigated differential diagnoses that should be noted with familial Mediterranean fever (FMF) and useful variables for differentiation in a large Japanese cohort.

METHODS

Patients aged ≥13 years who were clinically suspected of having FMF by Livneh criteria were studied 1 year after MEFV genetic testing. Patients ultimately diagnosed with other diseases were studied, and the association among each disease, patient characteristics, and clinical variables were analysed using multiple correspondence analysis.

RESULTS

In total, 504 patients were included in this study; 34 (6.7%) were diagnosed with a disease other than FMF. The most common diagnosis was Behçet's disease, followed by periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome, inflammatory bowel disease, myelodysplastic syndromes (MDS), and infectious diseases. Although none of the non-FMF patients had exon 10 variants, some responded to colchicine treatment. Multiple correspondence analysis suggested that atypical symptoms such as stomatitis were associated with Behçet's disease and PFAPA syndrome, whereas characteristic situations such as disease onset ≥40 years were associated with MDS and infectious diseases.

CONCLUSION

Careful follow-ups and reanalysis of the diagnosis should be performed for patients with atypical findings and no exon 10 variants, even if their symptoms meet the clinical criteria for FMF.

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.

Associations of MEFV gene variants, IL-33, and sST2 with the risk of Henoch-Schönlein purpura in children

Objective

Henoch-Schönlein purpura (HSP) is the most common systemic vasculitis in children. HSP is a multifactorial inflammatory disease, but its pathogenesis is still unclear. The pathogenicity of familial Mediterranean fever gene (MEFV) variants in HSP remains controversial. The objective of this study was to evaluate relationships between MEFV variants and susceptibility to HSP and their associations with clinical outcomes. We also investigated levels of IL-33 and soluble suppression of tumorigenicity 2 (sST2) in children with HSP and their clinical significance.

Methods

We selected 100 children with HSP as the case group. The control group consisted of 50 children who visited the hospital for physical health examinations. All subjects were screened for MEFV gene exon mutations, and levels of IL-33 and sST2 were measured.

Results

The frequency of MEFV variants was significantly greater in HSP patients than in healthy controls. The variant with the highest frequency was E148Q. The frequency of the C allele of the MEFV variant E148Q was 32 % in HSP patients and 18 % in controls (P-adjust = 0.04). Patients with the MEFV E148Q variant had more frequent joint involvement and recurrent purpura and higher levels of IL-33 and C-reactive protein (CRP). Levels of IL-33 and sST2 in children with HSP were significantly higher than those in the control group, and the sST2/IL-33 ratio in children with HSP was unbalanced (P-adjust <0.05). Logistic regression analysis revealed the presence of E148Q and an unbalanced sST2/IL-33 ratio to be independent risk factors for HSP.

Conclusion

The results of this study suggest that the MEFV variant E148Q is associated with HSP susceptibility in Chinese children and that carriers of the variant may have more severe clinical manifestations and greater inflammatory responses. E148Q and the sST2/IL-33 ratio may play important roles in the pathogenesis of HSP.

Old paradigms and new concepts in familial Mediterranean fever (FMF): an update 2023

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease characterized by recurrent attacks of fever and polyserositis. Its first description as a new entity was published by Siegal in 1945. Colchicine has been the treatment of choice for this disease since 1972. Significant progress has been made over the years in understanding FMF's clinical features, diagnosis, mode of inheritance, pathogenesis and therapeutic approach. However, many old paradigms related to FMF have proven inaccurate, leading to the emergence of new concepts that provide more precise insights. The term 'FMF' is no longer appropriate as the disease is found beyond the Mediterranean basin. The concept of diagnosis based only upon clinical ground proved to be wrong. The paradigm that MEFV mutations in FMF lead to loss of function of the encoded peptide pyrin turned out to be a gain of function mutation. Finally, the concept that as a genetic disease FMF should be treated for life was found to be inaccurate for the subpopulation of the heterozygote patients. Thus, the breakthroughs of identifying the gene associated with the disease (MEFV) and the deciphering of its pathogenesis revolutionized our old paradigms and replaced them with new and more precise insights.

Colchicine-resistant sacroiliitis in a Japanese patient with familial Mediterranean fever

The articular involvement in patients with familial Mediterranean fever (FMF) represents a clinical characteristic of acute monoarthritis with pain and hydrarthrosis, which always resolves spontaneously. Colchicine prevents painful arthritis attacks in most FMF cases. Spondyloarthritis is rarely associated with Japanese patients with FMF. Here, we report a Japanese male patient with FMF-related axial joint involvement. A 43-year-old male Japanese patient who presented with recurrent febrile episodes with hip joint and back pain was referred to our hospital. He carried heterozygous variants in exon 2 (L110P/E148Q) of the MEFV gene. FMF was suspected, and oral administration of colchicine (1 mg/day) was initiated. Colchicine treatment improved his febrile attack with hip joint pain. He was diagnosed as having FMF based on the Tel-Hashomer diagnostic criteria for FMF since he fulfilled one major criterion (repeated febrile attack accompanied by hip joint pain) and one minor criterion (improvement with colchicine treatment). Although the human leucocyte antigen-B27 allele was not detected, sacroiliitis-related symptoms progressed despite the ongoing colchicine treatment. Salazosulphapyridine and methotrexate were administered in addition to colchicine; however, these treatments were not effective. Canakinumab treatment successfully resolved this unique aspect of sacroiliitis, and the patient was finally diagnosed with FMF-associated axial joint involvement.

Genetic and clinical features of familial mediterranean fever (FMF) in a homogeneous cohort of patients from South-Eastern Italy

Familial Mediterranean Fever (FMF) is linked with the MEFV gene and is the commonest among monogenic autoinflammatory diseases, with high prevalence in the Mediterranean basin. Although the clinical presentation of FMF has a major role in diagnosis, genotype/phenotype correlations and the role of "benign" gene variants (as R202Q) appear highly variable and incompletely clear, making difficult to select the most effective strategy in the management of patients. Aim of the present study was to investigate the clinical presentation and the genetic background in a homogenous cohort of patients from Apulia (south eastern Italy). We investigated 217 patients with a clinical suspect of autoinflammatory diseases, who were characterized for the occurrence of specific symptoms and with next generation sequencing by a 4-gene panel including MEFV, MVK, NLRP3 and TNFRSF1A. A genetic change was identified in 122 (53.7%) patients, with 161 different MEFV variants recorded in 100 individuals, 10 variants in NLRP3, and 6 each in TNFRSF1A and MVK. The benign variant R202Q was largely prevalent (41.6% of all MEFV variants). When patients were selected according the number of pathogenic MEFV variants (0, 1, or 2 pathogenic variants), results failed to show significant links between the frequency of symptoms and the number of pathogenic variants. Only family history and Pras score (indicative for severity of disease) predicted the presence of pathogenic variants, as compared with carriers of variants considered of uncertain significance or benign. Fever >38 °C and arthralgias appeared more frequently in R202Q-positive patients than in non-R202Q carriers. These two subgroups showed comparable duration of fever, occurrence of myalgia, abdominal and chest pain, Pras, and IFFS scores. In conclusion, results confirm that FMF manifests in mild form in non-middle eastern patients. This possibility partly affects the reliability of clinical criteria/scores. Furthermore, the presence of the R202Q variant might not be completely neutral in selected groups of patients.

Familial Mediterranean Fever in Spain: Time Trend and Spatial Distribution of the Hospitalizations

Familial Mediterranean Fever (FMF) is a rare, hereditary, auto-inflammatory disease. The aims of this study were to explore the time trend and geographical distribution of hospitalizations in Spain from 2008 to 2015. We identified hospitalizations of FMF from the Spanish Minimum Basic Data Set at hospital discharge, using ICD-9-CM code 277.31. Age-specific and age-adjusted hospitalization rates were calculated. The time trend and the average percentage change were analyzed using Joinpoint regression. Standardized morbidity ratios were calculated and mapped by province. A total of 960 FMF-related hospitalizations (52% men) were identified across the period 2008-2015, with an increase in hospitalizations of 4.9% per year being detected (p < 0.05). The risk of hospitalization was higher than expected for the national total (SMR > 1) in 13 provinces (5 in the Mediterranean area), and lower (SMR < 1) in 14 provinces (3 in the Mediterranean area). There was an increase in hospitalizations of patients with FMF in Spain throughout the study period, with a risk of hospitalization that was higher, though not exclusively so, in provinces along the Mediterranean coast. These findings contribute to the visibility of FMF and provide useful information for health planning. Further research should take into account new population-based information, in order to continue monitoring this disease.

Two Cases of Familial Mediterranean Fever Involving MEFV Variants: The Importance of Differentiating the Diagnosis from COVID-19

Familial Mediterranean fever (FMF) is an inherited autoinflammatory disease associated with the MEFV gene. FMF is common in Mediterranean peoples but not highly recognized in Japan. We herein report two cases of Japanese FMF patients who were diagnosed by genetic testing for the MEFV gene during the coronavirus disease 2019 (COVID-19) pandemic. Both patients presented with symptoms similar to COVID-19, which delayed the definitive diagnosis. Patients with a confirmed diagnosis of FMF may be eligible for physical, emotional, and financial benefits. Therefore, the COVID-19 pandemic highlights the importance of differentiating the diagnosis by genetic testing.

＜Editors' Choice＞ Myelodysplastic syndrome with trisomy 8 presenting periodic fever and multiple MEFV gene variants outside exon 10: a case report

Myelodysplastic syndrome is associated with the development of autoinflammatory conditions, such as recurrent fever, polymyalgia, arthralgia, and erythema. Trisomy 8 is a common chromosomal abnormality in patients with myelodysplastic syndrome. Myelodysplastic syndrome with trisomy 8 involves autoinflammatory conditions, especially Behçet's disease-like symptoms with intestinal mucosal damage. MEFV variants, particularly those in exon 10, are pathogenic in familial Mediterranean fever, the most common autoinflammatory disease, presenting typical symptoms such as periodic fever and pleuritis/pericarditis/peritonitis. MEFV variants outside exon 10 are common in Japanese patients with familial Mediterranean fever and are associated with atypical symptoms, including myalgia and erythema. MEFV variants in myelodysplastic syndrome with trisomy 8 have rarely been investigated, although myelodysplastic syndrome with trisomy 8 might develop autoinflammatory conditions similar to those in familial Mediterranean fever. We encountered a 67-year-old man who had myelodysplastic syndrome with trisomy 8 and multiple MEFV variants outside exon 10. He presented with periodic fever, as well as chest/abdominal pain, myalgia, and erythema, although the symptoms did not fulfill the diagnostic criteria of familial Mediterranean fever. We discussed the possibility that these symptoms are modified by MEFV variants outside exon 10 in myelodysplastic syndrome with trisomy 8.

Investigation of Acceptance of Illness and Religious Coping in Patients with Familial Mediterranean Fever in Turkey

This study aimed to determine the Acceptance of Illness and use of religious coping in patients with Familial Mediterranean Fever (FMF). This descriptive and cross-sectional study was conducted with 209 FMF patients, who came to be examined in the Rheumatology outpatient clinic of a Training and Research Hospital in Turkey between June and October 2020. Data were obtained using a Patient Information Form, the Acceptance of Illness Scale, and the Religious Coping Styles Scale. The patients' mean Acceptance of Illness score was 21.14 ± 8.44 (moderate level), their mean positive religious coping score was 20.46 ± 5.97, and their mean negative religious coping score was 10.63 ± 5.01. There was a weak, negative correlation between the patients' Acceptance of Illness and their negative religious coping. Nurses should help patients to develop their Religious Coping Styles by taking into consideration their beliefs, values, cultural, and social backgrounds.

Clinical perspectives and therapeutic strategies: pediatric autoinflammatory disease-a multi-faceted approach to fever of unknown origin of childhood

Among the different etiologies for fever of unknown origin in children, infectious diseases are the most frequent final diagnosis, followed by autoimmune diseases and malignancies. Autoinflammatory diseases are relatively rare among children and are frequently overlooked as differential diagnoses for fever of unknown origin. Once the possibility of a particular autoimmune disease is considered by physicians, the diagnosis might be easily made by a genetic approach because many of autoinflammatory diseases are of monogenic origin. To reach the diagnosis, detailed history-taking, precise physical examinations, and cytokine profiling as well as extensive mutation analysis of candidate genes should be undertaken for febrile children. Such the approach will protect the patients, and their family to undergo “diagnostic odyssey” in which unnecessary and sometimes risky diagnostic and therapeutic interventions are taken.

This short review discusses the clinical and laboratory features of familial Mediterranean fever and systemic juvenile idiopathic arthritis, as representative illnesses of monogenic and polygenic autoinflammatory diseases, respectively. Cytokine profiling and mutation analyses both help to understand and decipher the heterogeneous pathologies in both disease categories.

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.

Familial Mediterranean Fever: How to Interpret Genetic Results? How to Treat? A Quarter of a Century After the Association with the Mefv Gene

PURPOSE OF REVIEW

To provide an up-to-date approach to diagnosis and management of FMF patients.

RECENT FINDINGS

Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease and prototype monogenic autoinflammatory recurrent fever syndrome. Although it is one of the well-known autoinflammatory disorders, evaluations in the etiopathogenesis and genetics of the disease have shown that FMF is more complex than previously known. Since the number of reported MEFV variants increased, evaluating the genetic test results has become more challenging. Here, we suggest a roadmap for clinicians to facilitate their decisions regarding diagnosis, treatment, and follow-up in FMF patients with different genotype-phenotype combinations. The correct interpretation of genetic test results is crucial for timely diagnosis, appropriate treatment, and follow-up of FMF patients.

The clinical effect of gene mutations in familial Mediterranean fever disease

BACKGROUND

Familial Mediterranean fever (FMF) is a self-limiting, autoinflammatory disease characterized by inflammation of the serosal surfaces and recurrent episodes of fever. The aim of this study is to determine the effect of genetic mutations on clinical features in children with FMF.

METHODS

A total of 303 patients aged 0-18 years, who were diagnosed with FMF, according to Yalcinkaya-Özen diagnostic criteria and whose Mediterranean fever gene (MEFV) analysis was studied, were evaluated retrospectively. The clinical and demographic characteristics of the patients and the relationship between common alleles and genotypes were investigated.

RESULTS

The most common mutation in patients was M694V heterozygous. When the patients were divided into four groups, M694V homozygous, M694V heterozygous, M694V/other allele combined heterozygous, and other mutations, Arthritis was statistically significantly higher in the group that was M694V homozygous compared to the other groups. It was observed that the presence of the M694V allele significantly increased the frequency of periodic fever, aphthous stomatitis, pharyngitis, adenitis syndrome. The frequency of arthritis was significantly higher in patients who were E148Q homozygous than in patients who were heterozygous. Appendectomy history was significantly higher in the group carrying the V726A allele.

CONCLUSIONS

FMF disease and the effect of genetics on the disease can be better understood, thanks to studies evaluating the genotype-phenotype relationship. In this regard, we believe that studies evaluating the clinical and genotype relationship with a large series are needed.

Role of E148Q in familial Mediterranean fever with an exon 10 mutation in MEFV

BACKGROUND

Familial Mediterranean fever (FMF) is an autosomal recessive disease caused by mutations in the MEFV gene. Mutations in exon 10 are associated with typical FMF. Most Japanese patients with typical FMF are compound heterozygotes of M694I in exon 10 and E148Q in exon 2. However, the pathogenic role of E148Q remains controversial.

METHODS

We assessed symptoms and serum cytokines among patients with FMF and their family members. They were divided into three subgroups, based on MEFV mutations: individuals carrying M694I and E148Q (group A, n = 14), individuals carrying M694I, but not E148Q (group B, n = 10), and individuals carrying E148Q, but not M694I (group C, n = 11).

RESULTS

All but one individual in group A had typical FMF phenotypes, whereas no individual in groups B and C exhibited any episodes of fever or serositis. The serum levels of interleukin-18 during the afebrile phase were significantly elevated in group A (2,806 ± 2,107 pg/mL), compared to those in groups B (499 ± 369 pg/mL) and C (427 ± 410 pg/mL). No difference in interleukin-6 levels was observed among the three groups.

CONCLUSIONS

These findings indicated that E148Q may contribute to disease development of FMF in Japanese patients carrying the heterozygous M694I mutation in MEFV and that genetic testing of both parents would lead to better counseling for their children.

Is there a role for 18F-FDG PET-CT in Familial Mediterranean fever? A case report and overview of the literature

Familial Mediterranean Fever (FMF) is an autosomal recessive disorder that is characterised by recurrent attacks of fever and painful polyserositis mainly affecting the peritoneum, synovium and pleura that usually begins in childhood. Even though diagnostic criteria have been proposed, conclusive imaging findings or haematological markers for the diagnosis or follow-up of FMF are still lacking. In this case report we present the ¹⁸F-FDG PET-CT findings in a 55 year old female during an attack of FMF. We briefly discuss the added value of ¹⁸F-FDG PET-CT in the diagnosis and the work-up of FMF, which may open up new applications for ¹⁸F-FDG PET-CT in non-infectious inflammatory diseases.

Atypical Familial Mediterranean Fever in a Japanese Boy with Heterozygous MEFV p.Ser503Cys Exon 5 Variant

Periodic fever syndromes are heterogeneous diseases. Familial Mediterranean fever (FMF) is one of the hereditary periodic fever diseases caused by a Mediterranean fever (MEFV) gene abnormality. FMF can be categorized as typical or atypical, based on clinical findings and genetic screening. Atypical FMF has a wide variation of clinical findings and disease-causing mutations of MEFV. Therefore, it is sometimes difficult to diagnose an unknown fever as FMF. To date, a large number of various typical and atypical FMF cases have been reported in Japan. Here, we describe a Japanese boy with heterozygous MEFV p.Ser503Cys exon 5 variant who developed periodic fever. He was treated with colchicine; a complete eradication of his fever and various accompanying symptoms have been subsequently achieved for more than a year. Given that there have been a few reports about patients with this variant, little is known about the genetic and phenotypic role of heterozygous MEFV p.Ser503Cys exon 5 variant. It is therefore imperative to consider atypical FMF as a differential diagnosis when a periodic fever is encountered. Furthermore, we suggest that it is worthwhile to integrate MEFV gene analysis with the potential effects of colchicine treatment in patients with periodic fever.

Rapid Flow Cytometry-Based Assay for the Functional Classification of MEFV Variants

PURPOSE

Pathogenic MEFV variants cause pyrin-associated autoinflammatory diseases (PAADs), which include familial Mediterranean fever (FMF), FMF-like disease, and pyrin-associated autoinflammation with neutrophilic dermatosis (PAAND). The diagnosis of PAADs is established by clinical phenotypic and genetic analyses. However, the pathogenicity of most MEFV variants remains controversial, as they have not been functionally evaluated. This study aimed to establish and validate a new functional assay to evaluate the pathogenicity of MEFV variants.

METHODS

We transfected THP-1 monocytes with 32 MEFV variants and analyzed their effects on cell death with or without stimulation with Clostridium difficile toxin A (TcdA) or UCN-01. These variants were classified using hierarchical cluster analysis. Macrophages were obtained from three healthy controls and two patients with a novel homozygous MEFV^P257L variant, for comparison of IL-1β secretion using a cell-based assay and a novel THP-1-based assay.

RESULTS

Disease-associated MEFV variants induced variable degrees of spontaneous or TcdA/UCN-01-induced cell death in THP-1. Cell death was caspase-1 dependent and was accompanied by ASC speck formation and IL-1β secretion, indicating that pathogenic MEFV variants induced abnormal pyrin inflammasome activation and subsequent pyroptotic cell deaths in this assay. The MEFV variants (n = 32) exhibiting distinct response signatures were classified into 6 clusters, which showed a good correlation with the clinical phenotypes. Regarding the pathogenicity of MEFV^P257L variants, the results were consistent between the cell-based assay and the THP-1-based assay.

CONCLUSION

Our assay facilitates a rapid and comprehensive assessment of the pathogenicity of MEFV variants and contributes to a refined definition of PAAD subtypes.

MEFV E148Q variant is more associated with familial Mediterranean fever when combined with other non-exon 10 MEFV variants in Japanese patients with recurrent fever

OBJECTIVE

To investigate the genetic characteristics of one of the MEFV gene variants, p.Glu148Gln (E148Q), in patients with familial Mediterranean fever (FMF) and examine its significance in Japanese patients with recurrent fever.

METHODS

The clinical phenotype and genomic variants of systemic autoinflammatory diseases (SAIDs), including MEFV, were analyzed in 211 Japanese patients with recurrent fever. Genetic analysis was performed via next-generation sequencing of exons, including exon-intron boundaries.

RESULTS

Twelve patients met the diagnostic criteria for SAIDs other than FMF. Considering 199 patients with recurrent fever, 137 cases (68.8%) were clinically diagnosed with FMF. Although Bonferroni-adjusted p-value did not reach significance level, the group containing heterozygous E148Q and other variants tended to be at higher risk of developing the FMF phenotype (nominal p = .036) than the group with heterozygous E148Q only. Comparison between the group with heterozygous E148Q and other variants and the heterozygous group containing non-E148Q showed no statistically significant difference in FMF phenotype expression (nominal p = 1.00).

CONCLUSION

Patients with heterozygous E148Q and other variants exhibited higher expression of FMF phenotype than those with heterozygous E148Q only, and suggested that other variants than E148Q as well as exon 10 variants might contribute to the FMF phenotype.

Comorbidities and phenotype-genotype correlation in children with familial Mediterranean fever

Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease manifesting with phenotypic heterogeneity. The phenotype-genotype correlation is not established clearly yet. Furthermore, some comorbidities such as vasculitis and inflammatory arthritis may accompany FMF. Herein, we aimed to define phenotype-genotype correlation and comorbid diseases of children with FMF. The medical records of 1687 children diagnosed and followed up as FMF were reviewed retrospectively. Disease severity was assessed by PRAS score. A total of 1687 children (841 girls, 846 boys) were involved in the study. The mean ± standard deviation of current age, age at symptom onset, and age at diagnosis were 13.1 ± 5.4, 5.4 ± 4, and 8 ± 4.2 years, respectively. Median (min-max) follow-up period was 3 (0.5-18) years. Among them, 118 (7%) patients had at least one concomitant disease and 72% of them were carrying at least one M694V mutation. Patients with a concomitant disease expressed a more severe course of disease when compared to ones without a concomitant disease (23.7% vs 8.8%, p < 0.001). Children carrying homozygous M694V mutation had significantly earlier age of disease onset and severe disease course (p < 0.001). Forty-four patients (2.6%) were colchicine resistant and most of them were carrying homozygous M694V mutation. Sixteen colchicine-resistant patients were treated with anakinra while 28 received canakinumab. Juvenile idiopathic arthritis (JIA) and immunoglobulin A vasculitis were the most commonly seen associated diseases and the patients with a concomitant disease demonstrated more severe course. This is the largest pediatric cohort studied and presented since now. We confirmed that carrying M694V mutation is associated both with a severe disease course and a predisposition to comorbidities.

The evaluation of gene polymorphisms associated with autoinflammatory syndrome in patients with palindromic rheumatism complicated by intermittent hydrarthrosis

OBJECTIVES

Palindromic rheumatism (PR) is a type of acute arthritis or periarthritis characterized by recurrence, paroxysmal, or intermittent disease attacks and occasionally progresses to other types of rheumatic disease. PR patients who are anti-citrullinated protein antibodies (ACPA)-negative have a high prevalence of MEFV gene polymorphisms, and intermittent hydrarthrosis (IH) is also associated with MEFV polymorphisms. The purpose of this study was to evaluate the clinical characteristics of and autoinflammatory syndrome-associated gene polymorphisms in patients with PR and IH and to identify predictive factors for developing other rheumatic diseases.

METHODS

Six PR patients (four females; median age at disease onset, 20.0 years; median age at evaluation, 47.0 years) were retrospectively evaluated for clinical features and polymorphisms in genes responsible for autoinflammatory diseases.

RESULTS

All six patients fulfilled the diagnostic criteria for PR and showed clinical feature of IH. Two presented with recurrent fever. All six patients were negative for rheumatoid factor and ACPA and had normal articular X-ray findings. Among the six patients, MEFV gene polymorphisms known to cause FMF were identified in four, CIAS1 mutation was observed in one, and TNFRSFIA mutation was observed in one. Colchicine was effective in three patients with MEFV polymorphisms. The other five patients continued to experience PR, although three patients achieved remission with medication.

CONCLUSIONS

PR presenting with IH might be associated with gene polymorphisms responsible for autoinflammatory diseases; colchicine appears to be effective in these patients.Key Point• Palindromic rheumatism with intermittent hydrarthrosis might be associated with gene polymorphisms responsible for autoinflammatory diseases.

MEFV gene mutations in neuro-Behçet's disease and neuro-Sweet disease

Mediterranean fever (MEFV) gene mutations are associated with familial Mediterranean fever (FMF). Recent studies have suggested that MEFV gene mutations may act as disease modifiers in neuro‐Behçet's (NBD) disease and neuro‐Sweet disease (NSD). We investigated MEFV genes and clinical features in 17 patients with NBD or NSD. MEFV gene mutations were frequently observed (70.6%). Headaches and exertional leg pain were associated with MEFV gene mutations (P < 0.05). Moreover, higher frequency of white matter lesions without sites predilection (P < 0.05) and non‐parenchymal lesions (P < 0.05) were also observed. MEFV gene mutations may be associated with particular findings and lesion sites.

Prevalence of MEFV gene mutations in a large cohort of patients with suspected familial Mediterranean fever in Central Anatolia

BACKGROUND

Familial Mediterranean fever (FMF), an autosomal recessive, autoinflammatory disease that is common in Arabs, Jews, Armenians and Turks, is caused by mutations in the MEFV gene, which encodes a protein called pyrin. The disease is characterised by recurrent fever, peritonitis, pleuritis, abdominal pain and arthralgia.

OBJECTIVE

Determine the distributions of MEFV mutations and their relationship with clinical manifestations.

DESIGN

Retrospective, descriptive.

SETTING

Turkish community.

SUBJECTS AND METHODS

The study included patients with complaints related to FMF who were admitted to the research hospital of Cumhuriyet University between 2005 and 2017. FMF was diagnosed by physical examination using the Tel-Hashomer criteria. MEFV mutations were detected by reverse hybridization strip assay and pyrosequencing.

MAIN OUTCOME MEASURE

The prevalence of specific MEFV gene mutations in a large cohort of Middle Anatolia.

SAMPLE SIZE

10 033 patients admitted, 1223 with confirmed mutations.

RESULTS

Of 1684 patients diagnosed by Tel-Hashomer criteria, mutation screening confirmed that 1223 patients (72.6%) had FMF. Male/female ratio of the FMF patients was 1.3:1. One or more FMF mutations were found in 4497 patients (44.8%). 3262 had heterozygous or carrier mutations, 821 had compound heterozygous mutation, 381 had homozygous mutations, and 21 had triple mutations. Sixty-six percent had a family history of the disease and 13.7% of the patients had parental consanguinity. Main symptoms found in the patients were abdominal pain (85.2%), fever (84%), chest pain (30.2%), arthralgia (28.6%), rash or erysipelas-like erythema (8.2%). The most common mutation in this population was M694V (39%) of 5753 alleles.

CONCLUSION

M694V was the most frequent mutation in our population (Middle Anatolia, Turkey) and cause severe forms of the disease. Patients with E148Q, V726A and R761H mutations may have milder FMF symptoms. There was a high rate of carriers in our study group.

LIMITATIONS

Amyloidosis, an important complication of the disease, needs to be analyzed.

CONFLICT OF INTEREST

None.

Atypical Familial Mediterranean Fever Presenting with Recurrent Migratory Polyarthritis

A 38-year-old Japanese man without any significant past medical history was referred to our clinic to undergo further examination for a "refractory infection in his joints". He suffered recurrent migratory polyarthritis starting from bilateral knees to his right elbow. Certain antibiotic therapies appeared to improve his symptoms, but the symptoms recurred due to the migratory nature of arthritis. A diagnosis of familial Mediterranean fever (FMF) was considered and diagnostic tests were performed. Not many differential diagnoses exist for migratory polyarthritis, particularly when it has a recurrent nature. The administration of antibiotics without sufficient diagnostic consideration can cause a delay in making an accurate diagnosis and thereby also cause a delay in administering appropriate treatment.

The grandfather's fever

An 86-year-old Caucasian man had prior episodes of fever (up to 38 °C), mild abdominal pain, tachycardia, and malaise in the last 3 months, lasting 2-3 days. He never suffered from abdominal or chest pain, rash, or arthralgia. Major causes of fever were excluded (pulmonary, urinary, abdomen, skin infections, neoplasms, and major rheumatologic disorders). The patient was native of Altamura with a family history of familial Mediterranean fever (FMF). The genetic testing confirmed the presence of MEFV gene variants c.442G>C (E148Q) on exon 2 and c.2282G>A (R761H) on exon 10, all in heterozygosity. Mildly elevated serum transaminases suggested an ongoing form of FMF hepatitis on nonalcoholic liver steatosis. The patient started colchicine 1 mg/day that induced symptom control and normalization of inflammatory markers, hyperbilirubinemia, and markers of cholestasis. Symptoms of FMF can appear at any age in life and our patient represents a very late-onset clinical case. The Apulian region has a consistent clustering of MEFV variants and FMF families with affected individuals in multiple consecutive generations. Families show unique clinical features and rare signs of secondary amyloidosis without kidney damage. Genetic and environmental bases of this phenotypic variant are under scrutiny. Colchicine lifetime remains the mainstay of treatment in FMF patients. KEY POINTS: • Familial Mediterranean fever (FMF) is the most frequent hereditary monogenic recurrent fever syndrome, and symptoms can appear at any age in life. • Late-onset FMF approaches 30% in late adulthood, but in general, onset of FMF after the age of 40 (late onset FMF) is rare, usually associated with M694V heterozygosity. • In a local cluster of FMF families (Altamura, Puglia, Southern Italy), we report a very late-onset FMF (variants E148Q, R761H) in an 86-year-old patient with a positive family history of FMF in two generations of descendants. • While lifetime colchicine remains the mainstay of treatment in FMF patients, prospective studies need to identify the characteristics of several phenotypic variants accounting for (very)-late onset FMF.

Arterial stiffness in Familial Mediterranean Fever: correlations with disease-related parameters and colchicine treatment

INTRODUCTION/OBJECTIVES

Familial Mediterranean Fever is the most common autoinflammatory disease. As chronic inflammation may result in increased arterial stiffness, we aimed to investigate indices of arterial stiffness in patients with Familial Mediterranean Fever and their associations with disease-related factors and colchicine treatment.

METHOD

The study was conducted with 43 patients with Familial Mediterranean Fever, including 30 children, in attack free period and 42 healthy controls. Arterial stiffness was assessed by carotid-femoral pulse wave velocity and augmentation index.

RESULTS

Patients with Familial Mediterranean Fever presented similar carotid-femoral pulse wave velocity values to controls, but significantly higher augmentation index values (patients versus controls, 19.76% and 9.96%, P < 0.05). Augmentation index, adjusted for age and sex, was associated with complete response compared with partial response to treatment (B = - 17.78, 95% CI - 31.17 to - 4.40, P < 0.05) and the presence of M694V.M680I genotype (B = - 16.75, 95% CI - 33.81 to 0.30, P = 0.05). Carotid-femoral pulse wave velocity presented an inverse relationship with colchicine treatment duration (B = - 0.003, 95% CI - 0.006 to - 0.00, P < 0.05). Pulse wave velocity values adjusted for age and systolic blood pressure were associated with attack frequency (B = 0.48, 95% CI 0.01 to 0.96, P < 0.05). Addition of colchicine treatment duration to the model attenuated the association between carotid-femoral pulse wave velocity and attack frequency supporting the protective role of colchicine.

CONCLUSIONS

The normal values of carotid-femoral pulse wave velocity in Familial Mediterranean Fever patients may reflect the compliance to colchicine treatment, which seems to have a protective role against arterial stiffness. However, the increased values of augmentation index need further investigation.

KEY POINTS

• FMF patients are prone to present increased cardiovascular risk possibly due to inflammation. • Colchicine treatment may have protective role against arterial stiffness in FMF. • The normal values of cf-PWV in FMF patients may reflect the compliance to colchicine.

Late-onset familial Mediterranean fever in Japan

Objectives: Most patients with familial Mediterranean fever (FMF) have their first attack at age < 20 years. Information about late-onset (age ≥40 years) FMF is limited. We aimed to evaluate the demographic, clinical, and genetic characteristics of late-onset FMF patients in the Japanese population.Methods: We retrospectively analyzed 292 patients with FMF. Patients were divided into three groups according to age of disease onset: Group I, ≤19 years; Group II, 20-39 years; and Group III, ≥40 years.Results: Of 292 patients, 44 (15.1%) experienced their first attack at age ≥40 years. While high fever (97.7%) and arthritis (45.5%) were common symptoms in Group III patients, peritonitis (40.9%) and pleuritis (25.0%) were significantly lower than in other groups. The frequency of patients carrying p.M694I (18.2%), which is the most representative mutation in Japan, was significantly lower in Group III than in Group I. The response to colchicine therapy was good (95.1%) and similar in all groups.Conclusions: In Japan, more patients than expected had late-onset FMF. They had a milder form of disease, with less frequent peritonitis and pleuritis. The response to colchicine treatment was good. Clinicians should consider FMF for patients with unexplained recurrent febrile episodes, regardless of age.

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.

Vertebral artery dissection associated with familial Mediterranean fever and Behçet's disease

Vertebral artery dissection and recurrent meningitis are rare complications in Behçet's disease. Behçet's disease may be associated with familial Mediterranean fever. Here, we describe a 52‐year‐old woman with severe headache who exhibited recurrent meningitis and vertebral artery dissection. Cerebrospinal fluid showed high levels of interleukin‐6. Magnetic resonance imaging revealed right vertebral artery dissection. The patient had three heterozygous mutations in the familial Mediterranean fever gene (MEFV) gene. She fulfilled criteria for diagnosis of Behçet's disease and familial Mediterranean fever. In conclusion, mutations of the MEFV gene may cause neuro‐inflammatory disorders and cerebrovascular disorders by reducing anti‐inflammatory activity of pyrin.

Familial Mediterranean Fever in Chinese Children: A Case Series

Background: Familial Mediterranean fever (FMF) is an inherited auto-inflammatory disorder and is extremely rare in Chinese. This study aimed to investigate the demographic, clinical, and genetic features of FMF in a series of Chinese pediatric patients. Methods: This was a retrospective case series of children with recurrent febrile or inflammatory episodes and referred to the Peking Union Medical College Hospital between 06/2013 and 06/2018. All suspected patients were genetically diagnosed and met the Tel-Hashomer criteria for FMF. Demographic, clinical, genetic, and treatment characteristics were collected. Descriptive statistics were used. Results: Eleven patients were included (seven boys and four girls). The median age at the time of disease onset was 7.1 (range, 3-12) years, while the median age at diagnosis was 10.9 (range, 6-15) years. The median delay in diagnosis was 2.1 years (range, 6 months to 6.7 years). Fever (100%, 11/11) was the most common symptom, followed by joint pain (63.6%, 7/11), rash (54.5%, 6/11), abdominal pain (36.4%, 4/11), and oral ulcers (18.2%, 2/11), without evidence of amyloidosis. C-reactive protein (81.8%, 9/11) and erythrocyte sedimentation (90.9%, 10/11) were increased during attacks. All patients harbored one to five different MEFV mutations, with E148Q and L110P being the most frequent. A novel non-synonymous mutation F636Y in exon 10 was discovered. Favorable responses to colchicine was observed in all six treated patients. Conclusion: The most common variants in our study were E148Q and L110P. F636Y may found for the first time. Colchicine led to favorable responses in all treated patients.

Familial Mediterranean fever in Chinese adult patients

Objectives

FMF is the most frequent monogenic auto-inflammatory disease worldwide. There have been hardly any cases reported in the Chinese population. We aimed to describe the first cohort of adult FMF patients in China.

Methods

We evaluated all the adult patients suffering from FMF referred to our centre from April 2015 through March 2017. Patients were diagnosed clinically according to the Tel Hashomer criteria. Whole exome sequencing was performed in each patient.

Results

A total of 11 adult patients were diagnosed as FMF in our centre. The mean age of onset was 29.4 years (s.d. 18.2). All patients were of Chinese Han ethnicity with no positive family history. All patients had intermittent febrile episodes. During attacks, seven patients had generalized abdominal pain, three experienced chest pain, four developed arthritis and none reported erysipelas-like skin changes. No patient had evidence of AA amyloidosis. Every patient carried at least one variant in the MEFV gene. All patients had good response to colchicine.

Conclusion

Our study is the first to suggest the presence of FMF in the Chinese adult population. The late onset, often atypical and mild clinical manifestations and absence of AA amyloidosis in our patients might be related to low-penetrance and heterozygous MEFV variants. Our results await to be confirmed on larger Chinese populations.

Musculoskeletal manifestations occur predominantly in patients with later-onset familial Mediterranean fever: Data from a multicenter, prospective national cohort study in Japan

Background

We showed previously that Japanese individuals with familial Mediterranean fever (FMF) have a more atypical phenotype compared to endemic areas. The clinical differences between young-onset FMF (YOFMF), adult-onset FMF (AOFMF), and late-onset FMF (LOFMF) in Japan are unclear.

Methods

We enrolled 395 consecutive patients. We defined YOFMF, AOFMF, and LOFMF as the onset of FMF at < 20, 20–39, and ≥ 40 years of age, respectively. We compared clinical manifestations and MEFV mutations patterns among these groups.

Results

Median ages at onset were YOFMF 12.5 years (n = 182), AOFMF 28 years (n = 115), and LOFMF 51 years (n = 90). A family history, MEFV mutations in exon 10, and more than two MEFV mutations were significantly more frequent in the earlier-onset groups (p < 0.01, p < 0.0001, and p < 0.001, respectively). In the accompanying manifestations, thoracic and abdominal pain were significantly more frequent in the earlier-onset groups (p < 0.01 and p < 0.0001, respectively), whereas arthritis and myalgia were significantly more frequent in the later-onset groups (p < 0.0001 and p < 0.01, respectively). The multiple logistic regression analysis revealed that the presence of MEFV exon 10 mutations and earlier onset were significantly associated with serositis, whereas the absence of MEFV exon 10 mutations, later onset, and the presence of erysipelas-like erythema were significantly associated with musculoskeletal manifestations. There was no significant between-group difference in the responsiveness to colchicine.

Conclusions

Our results indicate that the later-onset FMF patients had a lower percentage of MEFV mutations in exon 10 and predominantly presented arthritis and myalgia. It is important to distinguish their FMF from other inflammatory diseases.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1738-1) contains supplementary material, which is available to authorized users.

Familial Mediterranean Fever Mutations in a Patient with Periodic Episodes of Systemic Pain Deriving from Cancer Bone Metastases

Familial Mediterranean fever (FMF), the most common autoinflammatory disorder, is characterized by recurrent febrile attacks and polyserositis. FMF is caused by mutations in MEFV, which encodes pyrin. In this report, we present an atypical FMF case with E148Q/L110P mutations in MEFV. The patient experienced periodic episodes of systemic pain originating from prostate cancer bone metastases. The pain attacks were prevented by continuous prophylactic therapy with colchicine. In this case, the presence of atypical FMF may have modulated the clinical manifestations of cancer bone metastases. To our knowledge, this is the first report to demonstrate the potential modulatory effect of MEFV mutations on cancer manifestations.

Familial Mediterranean Gene (MEFV) Mutation in Parents of Children with Familial Mediterranean Fever: What Are the Exceptions?

Objectives

Familial Mediterranean Fever (FMF) is one of the most prevalent periodic fever syndromes; MEFV, the responsible gene for the disease, is in the short arm of chromosome16. In the considerable count of the FMF patients, only one mutation is found in the MEFV and parents, who were the obligatory carriers for that mutation, were asymptomatic. The aim of this study was to evaluate these asymptomatic parents in regard to mutation in MEFV gene and similarity between parents and offspring patients.

Methods

In this cross-sectional study, asymptomatic parents of FMF patients enrolled the study were referred to periodic fever clinic or pediatric rheumatology clinic of Tehran University of Medical Sciences. The patients should have at least one mutation in MEFV gene and none of them had any family history of autoinflammatory disease. Twelve mutations in MEFV gene were assessed in the parents by Vienna Lab FMF Strip Assay kit by MAS PCR/Reverse hybridization.

Results

Forty-three patients and their parents participated in the study. Sixty-three percent (27) of patients were male. Onset of disease symptoms in 31 patients (72%) was before 4 years of old. Nine (21%) of the patients had homozygote, 16 (37%) compound heterozygote, and 17(40%) heterozygote for MEFV mutation; there was a case of complex alleles mutations (2%). M694V/M694V in 4 patients (9%) was the most homozygote genotype, and M694V/R761H in 4 (9%) and E148Q in 7 (16%) were the most compound heterozygote and heterozygote genotype, respectively. M694V, M680I, and E148Q were the most mutation in the parents. Overall, 41 patients had mutations similar to their parents' mutation, except 2 whose parents had no mutation, but a patient did.

Conclusion

It seems that occurrence of new mutations in offspring is not prevalent among FMF patients and there are other reasons for different clinical presentation in similar mutation carriers. On the other hand, in ethnicities with high prevalence of FMF, new mutation in descendant may occur, infrequently.

Atypical type of familial Mediterranean fever: An underdiagnosed cause of chronic aseptic meningitis

We report an atypical case of familial Mediterranean fever (FMF) concomitant with chronic aseptic meningitis. The patient experienced fever, abdominal and back pain because of serositis, and headache because of aseptic meningitis for 4 weeks. Blood examinations revealed increased white blood cells and serum amyloid A level. Medications, including steroids, did not improve his symptoms. However, the patient experienced immediate relief after the administration of colchicine. We diagnosed him as having atypical FMF based on the symptoms, especially positive response to colchicine, and heterozygous mutations on exon2 and 5 (E148Q/S503C) in MEFV gene. Unlike typical FMF, a cause of recurrent aseptic meningitis, atypical FMF might be an underdiagnosed cause of chronic aseptic meningitis.

Five Cases of Familial Mediterranean Fever in Japan: The Relationship with MEFV Mutations

Familial Mediterranean fever (FMF) is the most common genetic autoinflammatory disease, but it has been considered a rare disease in Japan. We herein describe five patients with FMF who were diagnosed both clinically and genetically at a single Japanese institute. A genetic investigation of Mediterranean fever (MEFV) detected heterozygosity for the compound mutations L110P/E148Q (n=2) and L110P/148Q/P369S/R406Q (n=1), and heterozygosity for M694I (n=1) and S503C (n=1). Colchicine prevented febrile attacks and accompanying symptoms in four patients. One patient with an S503C mutation showed resistance. Physicians should be aware of the characteristic symptoms, as well as the more unusual symptoms such as headache, when diagnosing FMF.

Lack of clear and univocal genotype-phenotype correlation in familial Mediterranean fever patients: A systematic review

Familial Mediterranean fever (FMF) is the most common autosomal recessive autoinflammatory disease. To date, following the isolation of more than 280 MEFV sequence variants, the genotype-phenotype correlation in FMF patients has been intensively investigated; however, an univocal and clear consensus has not been yet reached. Thus, the aim of this systematic review was to analyze the available literature findings in order to provide to scientific community an indirect estimation of the impact of genetic factors on the phenotypic variability of FMF. This systematic review has been conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. The p.M694V mutation was reported to have a relatively severe clinical course, similarly, patients homozygous for M694I and M680I, or carrying a combination of both at codons 694 and 680, have a severe disease. Also, patients homozygous for M694V and V726A variants experienced more severe clinical picture. Conversely, heterozygous p.V726A and p.E148Q genotypes have been correlated with a milder disease course. At present, doubts remain on the potential pathogenic role of E148Q variant. The heterogenity in clinical FMF manifestations reflects the changes occuring in repertoire of mutations. We believe that clinical criteria and gene tests, enhancing each other, could better support the diagnosis of FMF.