Guidelines for the genetic diagnosis of hereditary recurrent fevers

Update on the management of colchicine resistant Familial Mediterranean Fever (FMF)

Background

Familial Mediterranean Fever (FMF), an autoinflammatory disease, is characterized by self-limited inflammatory attacks of fever and polyserositis along with high acute phase response. Although colchicine remains the mainstay in treatment, intolerance and resistance in a certain portion of patients have been posing a problem for physicians.

Main body

Like many autoimmune and autoinflammatory diseases, many colchicine-resistant or intolerant FMF cases have been successfully treated with biologics. In addition, many studies have tested the efficacy of biologics in treating FMF manifestations.

Conclusion

Since carriers of FMF show significantly elevated levels of serum TNF alpha, IL-1, and IL-6, FMF patients who failed colchicine were successfully treated with anti IL-1, anti IL-6, or TNF inhibitors drugs. It is best to use colchicine in combination with biologics.

Pyrin dephosphorylation is sufficient to trigger inflammasome activation in familial Mediterranean fever patients

Familial Mediterranean fever (FMF) is the most frequent hereditary systemic autoinflammatory syndrome. FMF is usually caused by biallelic mutations in the MEFV gene, encoding Pyrin. Conclusive genetic evidence lacks for about 30% of patients diagnosed with clinical FMF. Pyrin is an inflammasome sensor maintained inactive by two kinases (PKN1/2). The consequences of MEFV mutations on inflammasome activation are still poorly understood. Here, we demonstrate that PKC superfamily inhibitors trigger inflammasome activation in monocytes from FMF patients while they trigger a delayed apoptosis in monocytes from healthy donors. The expression of the pathogenic p.M694V MEFV allele is necessary and sufficient for PKC inhibitors (or mutations precluding Pyrin phosphorylation) to trigger caspase‐1‐ and gasdermin D‐mediated pyroptosis. In line with colchicine efficacy in patients, colchicine fully blocks this response in FMF patients’ monocytes. These results indicate that Pyrin inflammasome activation is solely controlled by Pyrin (de)phosphorylation in FMF patients while a second control mechanism restricts its activation in healthy donors/non‐FMF patients. This study paves the way toward a functional characterization of MEFV variants and a functional test to diagnose FMF.

Clinical characteristics and genetic analyses of 187 patients with undefined autoinflammatory diseases

OBJECTIVES

To describe the clinical characteristics, treatment response and genetic findings in a large cohort of patients with undefined systemic autoinflammatory diseases (SAIDs).

METHODS

Clinical and genetic data from patients with undefined SAIDs were extracted from the Eurofever registry, an international web-based registry that retrospectively collects clinical information on patients with autoinflammatory diseases.

RESULTS

This study included 187 patients. Seven patients had a chronic disease course, 180 patients had a recurrent disease course. The median age at disease onset was 4.3 years. Patients had a median of 12 episodes per year, with a median duration of 4 days. Most commonly reported symptoms were arthralgia (n=113), myalgia (n=86), abdominal pain (n=89), fatigue (n=111), malaise (n=104) and mucocutaneous manifestations (n=128). In 24 patients, relatives were affected as well. In 15 patients, genetic variants were found in autoinflammatory genes. Patients with genetic variants more often had affected relatives compared with patients without genetic variants (p=0.005). Most patients responded well to non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, colchicine and anakinra. Complete remission was rarely achieved with NSAIDs alone. Notable patterns were found in patients with distinctive symptoms. Patients with pericarditis (n=11) were older at disease onset (33.8 years) and had fewer episodes per year (3.0/year) compared with other patients. Patients with an intellectual impairment (n=8) were younger at disease onset (2.2 years) and often had relatives affected (28.6%).

CONCLUSION

This study describes the clinical characteristics of a large cohort of patients with undefined SAIDs. Among these, patients with pericarditis and intellectual impairment appear to comprise distinct subsets.

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.

Successful management of colchicine resistant familial Mediterranean fever patients with a standardized canakinumab treatment protocol: a case series and literature review

Familial Mediterranean fever (FMF) is the most common monogenic auto-inflammatory disease characterized by recurrent attacks of fever and serositis. Although colchicine is the first line treatment in FMF, 5-10% of patients do not respond to colchicine. Canakinumab, an anti-IL-1β monoclonal antibody, has been reported to be effective and safe in colchicine-resistant FMF patients, but the adequate duration and interval of treatment is still a matter of debate. Aim of this study was to evaluate the success of the standardized treatment protocol for canakinumab applied in our Pediatric Rheumatology Department in colchicine-resistant FMF cases with a review of the literature. Nine patients included in this study had indications for canakinumab use as colchicine resistance and recurrent corticosteroid need for pleural/pericardial effusions. Canakinumab was administered monthly for 6 months (initial treatment), bimonthly for 6 months (maintenance treatment), then treatment was discontinued. For the patients who developed a new attack after one-year treatment period, canakinumab was readministered with 3-month intervals (continuation treatment). The mean follow-up time beginning from the first canakinumab injection was 24.3 ± 10.2 (6-33) months. None of the patients had an attack during the first-year treatment. Four of the patients developed an attack 9.0 ± 2.9 (6-12) months after discontinuation of treatment and switched to the continuation treatment period, with no more attacks. We suggest that this standard protocol may be used successfully in colchicine-resistant FMF patients.

Current practices for the genetic diagnosis of autoinflammatory diseases: results of a European Molecular Genetics Quality Network Survey

Monogenic autoinflammatory disorders (AIDs) are rare diseases caused by variants in genes regulating the innate immune system. The identification of the first four genes responsible for the prototype group of hereditary recurrent fevers prompted the development of genetic diagnosis, followed by external quality assessment and guidelines for the interpretation of sequence variants in these diseases. Recent changes in the diagnosis of genetic diseases, namely the implementation of next-generation sequencing (NGS), lead to discovery of the new genes associated with at least 40 novel AIDs, which revolutionized patient care and prognosis. However, these rapid advances resulted in nonstandardized molecular strategies that can influence genetic diagnosis and reporting of results. In order to assess factors, which may have an impact on performance and quality of results in the NGS era, we carried out an online survey among member laboratories of the European Molecular Genetics Quality Network, which highlighted different strategies being used and identified pitfalls that deserve discussion and improvement.

Molecular genetic evaluation of NLRP3, MVK and TNFRSF1A associated periodic fever syndromes

Periodic fever syndromes (PFSs) are a family of clinical disorders, which are characterized by recurrent episodes of fever in the absence of microbial, autoimmune or malign conditions. Most common types of PFSs are associated with four genes: MEFV, MVK, TNFRSF1A and NLRP3. This paper aims to add new data to the genotype-phenotype association of MVK-, TNFRSF-1A- and NLRP3-associated PFSs. A total number of 211 patients were evaluated. Two different approaches were used for the molecular genetic evaluation of MVK-, TNFRSF-1A- and NLRP3-associated PFSs. For the first 147 patients, Sanger sequence analysis of selected exons of MVK, TNFRSF1A and NLRP3 genes was done. For subsequent 64 patients, targeted NGS panel analysis, covering all exons of MVK, TNFRSF1A and NLRP3 genes, was used. A total number of 48 variants were detected. The "variant detection rate in index patients" was higher in the NGS group than Sanger sequencing group (19% vs. 15,1%). For the variant positive patients, a detailed genotype-phenotype table was built. In PFSs, lack of correlation exists between genotype and phenotype in the general population and even within the families. In some cases, mutations behave differently and yield unexpected phenotypes. In this study, we discussed the clinical effects of eight different variants we have detected in the MVK, TNFRSF1A and NLRP3 genes. Four of them were previously identified in patients with PFS. The remaining four were not reported in patients with PFS. Thus, we had to interpret their clinical effects by analysing their frequencies and in silico analysis predictions. We suggest that new studies are needed to evaluate the effects of these variants more clearly. To be able to demonstrate a clearer genotype-phenotype relationship, all PFS-related genes should be analysed together and the possibility of polygenic inheritance should be considered.

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.

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.

Association of pyrin mutations and autoinflammation with complex phenotype hidradenitis suppurativa: a case-control study

BACKGROUND

Hidradenitis suppurativa (HS) is a rare, debilitating neutrophilic dermatosis characterized by chronic inflammation of hair follicles. Many inflammatory conditions may accompany HS.

OBJECTIVES

To investigate the association of variants of the MEFV gene with a complex HS phenotype.

METHODS

Firstly, we identified the clinical characteristics of 119 patients with HS with a complex phenotype (Hurley stage III disease and/or additional inflammatory symptoms). Then, we searched for MEFV variants among these patients. The odds ratios (ORs) for pathogenic MEFV mutations were calculated using data from these patients with HS and 191 healthy controls.

RESULTS

The male/female ratio was higher, and the mean age of onset was earlier, in our complex HS group compared with patients with HS in general. Five of the patients with HS (4·2%) had a diagnosis of familial Mediterranean fever (FMF) with a standardized morbidity ratio of 45 [95% confidence interval (CI) 16·50-99·84, P < 0·001] when compared with the frequency of FMF in the general Turkish population. Of the patients with complex HS, 38% were positive for pathogenic variants of MEFV. The OR for carrying a pathogenic MEFV allele was 2·80 (95% CI 1·31-5·97, P < 0·001).

CONCLUSIONS

The frequency of MEFV mutations in the group of patients with complex HS was higher than that in healthy controls, suggesting that MEFV mutations may contribute to the pathogenesis of HS. Understanding the role of autoinflammation in HS is of fundamental importance for the development of novel therapies.

How to prescribe a genetic test for the diagnosis of autoinflammatory diseases?

The systemic autoinflammatory disorders (SAIDs) are associated with dysregulation of the innate immune system, affecting pro-inflammatory cytokines and apoptosis pathways. The spectrum of SAIDs continues to grow with over 30 different disorders identified to date. The main indication for genetic referral is when a patient presents with clinical symptoms consistent with one or more of the SAIDs. Thus, in making a referral for DNA screening, clinical information that supports the choice for screening of one or more SAIDs genes is required. Many of the SAIDs can display overlapping, partial or atypical symptoms, which makes the differential diagnosis extremely difficult and thus heavily dependent on genetic testing. Various attempts have been aimed at improving the efficiency of SAIDs diagnosis by proposing a set of clinical criteria to guide the genetic analysis of the SAIDs. In the last decade, due to application of the next-generation sequencing (NGS) the genetic diagnosis in patients with SAIDs have greatly improved; novel diseases and disease-associated genes have been identified and remarkable progress has been made in the genetic characterization of the undiagnosed patients and the sporadic cases. To date more than 800 variants have been recorded on the Infevers database, an online repository for DNA changes in genes associated with SAIDs (http://fmf.igh.cnrs.fr/ISSAID/infevers/). Recently, it has been updated with the new guidelines for classification of genetic variants pathogenicity in the in four most recognised SAIDs genes: MEFV, TNFRSF1A, NLRP3 and MVK.

Hereditary Autoinflammatory Disorders: Recognition and Treatment

The autoinflammatory diseases encompass approximately 30 monogenic disorders in which inborn errors in the innate immune system lead to episodic systemic inflammation. Largely mediated by dysregulation of myeloid cells, interleukin (IL)-1β, type I interferon, and NF-κB, these disorders have rapidly expanded over the past several years, and increasing numbers of patients identified. Crossover disorders, bridging autoinflammation and immunodeficiency, have recently been described. This article focuses on the clinical presentation of IL-1 and interferon-driven autoinflammatory disorders, and discusses novel diseases with features of immunodeficiency. Approaches to the clinical diagnosis, genetic testing, and treatment of these disorders are addressed.

Familial Mediterranean fever: overview of pathogenesis, clinical features and management

Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease, and is characterized by recurrent attacks of fever and polyserositis. It is associated with mutations in the MEFV gene encoding pyrin, which result in inflammasome activation and the uncontrolled production of IL-1β. FMF mainly affects individuals originating from the Mediterranean basin; however, a Japanese nationwide survey demonstrated that FMF is not uncommon in Japan. The survey also indicated that Japanese FMF patients are clinically or genetically distinct from Mediterranean FMF patients, suggesting a genotype-phenotype correlation. In Japanese patients with FMF, MEFV exon 10 mutations are associated with the more typical FMF phenotype. Conversely, Japanese FMF patients with mutations in MEFV exons 2 or 3 present with an atypical FMF phenotype. Colchicine is the mainstay of FMF treatment, and its regular use prevents febrile attacks and decreases the long-term risk of AA amyloidosis. However, a minority of FMF patients are colchicine-resistant, and anti-IL-1 treatment has proven beneficial in suppressing inflammation in these patients. Although Japanese FMF patients may develop less severe disease compared with Mediterranean FMF patients, they should nevertheless be treated early to prevent recurrent attacks and the subsequent development of AA amyloidosis.

A clinical update on inflammasomopathies

Inflammasomes are important elements of the innate immune defense. The most common autoinflammatory syndromes, as well a number of rare ones, are due to hereditary defects in the inflammasomes, hence are called inflammasomopathies. The recent clinical advances in these diseases will be reviewed, with special emphasis on reflecting the international collaborative work in the field. Recent recommendations for familial Mediterranean fever, cryopyrin-associated periodic syndromes and hyper-IgD syndrome/mevalonate kinase deficiency will be presented and diagnostics tests, treatment alternatives and follow-up recommendations will be summarized. The other rare inflammasomopathies will be briefly discussed based on clinical features; these diseases are pyogenic arthritis, pyoderma gangrenosum and acne, NLRC4-related macrophage-activation syndrome of enterocolitis, mutations in NLRP12 that cause hereditary periodic fever syndromes (familial cold inflammatory syndrome 2) and NLRP1-associated autoinflammation with arthritis and dyskeratosis.

Canakinumab for the Treatment of Autoinflammatory Recurrent Fever Syndromes

BACKGROUND

Familial Mediterranean fever, mevalonate kinase deficiency (also known as the hyperimmunoglobulinemia D syndrome), and the tumor necrosis factor receptor-associated periodic syndrome (TRAPS) are monogenic autoinflammatory diseases characterized by recurrent fever flares.

METHODS

We randomly assigned patients with genetically confirmed colchicine-resistant familial Mediterranean fever, mevalonate kinase deficiency, or TRAPS at the time of a flare to receive 150 mg of canakinumab subcutaneously or placebo every 4 weeks. Patients who did not have a resolution of their flare received an add-on injection of 150 mg of canakinumab. The primary outcome was complete response (resolution of flare and no flare until week 16). In the subsequent phase up to week 40, patients who had a complete response underwent a second randomization to receive canakinumab or placebo every 8 weeks. Patients who underwent a second randomization and had a subsequent flare and all other patients received open-label canakinumab.

RESULTS

At week 16, significantly more patients receiving canakinumab had a complete response than those receiving placebo: 61% vs. 6% of patients with colchicine-resistant familial Mediterranean fever (P<0.001), 35% versus 6% of those with mevalonate kinase deficiency (P=0.003), and 45% versus 8% of those with TRAPS (P=0.006). The inclusion of patients whose dose was increased to 300 mg every 4 weeks yielded a complete response in 71% of those with colchicine-resistant familial Mediterranean fever, 57% of those with mevalonate kinase deficiency, and 73% of those with TRAPS. After week 16, an extended dosing regimen (every 8 weeks) maintained disease control in 46% of patients with colchicine-resistant familial Mediterranean fever, 23% of those with mevalonate kinase deficiency, and 53% of those with TRAPS. Among patients who received canakinumab, the most frequently reported adverse events were infections (173.3, 313.5, and 148.0 per 100 patient-years among patients with colchicine-resistant familial Mediterranean fever, those with mevalonate kinase deficiency, and those with TRAPS, respectively), with a few being serious infections (6.6, 13.7, and 0.0 per 100 patient-years).

CONCLUSIONS

In this trial, canakinumab was effective in controlling and preventing flares in patients with colchicine-resistant familial Mediterranean fever, mevalonate kinase deficiency, and TRAPS. (Funded by Novartis; CLUSTER ClinicalTrials.gov number, NCT02059291 .).

Autoinflammatory Diseases with Periodic Fevers

PURPOSE OF REVIEW

One purpose of this review was to raise awareness for the new autoinflammatory syndromes. These diseases are increasingly recognized and are in the differential diagnosis of many disease states. We also aimed to review the latest recommendations for the diagnosis, management, and treatment of these patients.

RECENT FINDINGS

Familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS), and hyperimmunoglobulinemia D and periodic fever syndrome/mevalonate kinase deficiency (HIDS/MVKD) are the more common autoinflammatory diseases that are characterized by periodic fevers and attacks of inflammation. Recently much collaborative work has been done to understand the characteristics of these patients and to develop recommendations to guide the physicians in the care of these patients. These recent recommendations will be summarized for all four diseases. FMF is the most common periodic fever disease. We need to further understand the pathogenesis and the role of single mutations in the disease. Recently, the management and treatment of the disease have been nicely reviewed. CAPS is another interesting disease associated with severe complications. Anti-interleukin-1 (anti-IL-1) treatment provides cure for these patients. TRAPS is characterized by the longest delay in diagnosis; thus, both pediatricians and internists should be aware of the characteristic features and the follow-up of these patients. HIDS/MVKD is another autoinflammatory diseases characterized with fever attacks. The spectrum of disease manifestation is rather large in this disease, and we need further research on biomarkers for the optimal management of these patients.

A case of adult onset Still's disease with mutations of the MEFV gene who is partially responsive to colchicine

RATIONALE

Familial Mediterranean fever (FMF) and adult onset Still's disease (AOSD) have overlapping features, and are categorized as being on the spectrum of autoinflammatory diseases (AIDs). FMF is more prevalent in the Mediterranean region but rarely, described in the Chinese population.

PATIENT CONCERNS

We present an interesting case of a Han Chinese AOSD patient with episodic fever, wheals, and polyarthritis for 2 years.

DIAGNOSIS

Sequencing analysis found exon 2 mutations of the MEFV gene (c.329T>C [L110P], and c.442G>C [E148Q]).

INTERVENTION

Her arthritis was well-controlled with colchicine treatment, but fever, and rashes were not.

OUTCOMES

She eventually received tocilizumab, in addition to colchicine, and her symptoms completely disappeared.

LESSONS

MEFV mutations may exist in AOSD patients, and treatment with colchicine might be helpful in such patients.

New workflow for classification of genetic variants' pathogenicity applied to hereditary recurrent fevers by the International Study Group for Systemic Autoinflammatory Diseases (INSAID)

BACKGROUND

Hereditary recurrent fevers (HRFs) are rare inflammatory diseases sharing similar clinical symptoms and effectively treated with anti-inflammatory biological drugs. Accurate diagnosis of HRF relies heavily on genetic testing.

OBJECTIVES

This study aimed to obtain an experts' consensus on the clinical significance of gene variants in four well-known HRF genes: MEFV, TNFRSF1A, NLRP3 and MVK.

METHODS

We configured a MOLGENIS web platform to share and analyse pathogenicity classifications of the variants and to manage a consensus-based classification process. Four experts in HRF genetics submitted independent classifications of 858 variants. Classifications were driven to consensus by recruiting four more expert opinions and by targeting discordant classifications in five iterative rounds.

RESULTS

Consensus classification was reached for 804/858 variants (94%). None of the unsolved variants (6%) remained with opposite classifications (eg, pathogenic vs benign). New mutational hotspots were found in all genes. We noted a lower pathogenic variant load and a higher fraction of variants with unknown or unsolved clinical significance in the MEFV gene.

CONCLUSION

Applying a consensus-driven process on the pathogenicity assessment of experts yielded rapid classification of almost all variants of four HRF genes. The high-throughput database will profoundly assist clinicians and geneticists in the diagnosis of HRFs. The configured MOLGENIS platform and consensus evolution protocol are usable for assembly of other variant pathogenicity databases. The MOLGENIS software is available for reuse at http://github.com/molgenis/molgenis; the specific HRF configuration is available at http://molgenis.org/said/. The HRF pathogenicity classifications will be published on the INFEVERS database at https://fmf.igh.cnrs.fr/ISSAID/infevers/.

[Familial Mediterranean fever]

Familial Mediterranean Fever (FMF) is the most frequent monogenic auto-inflammatory disease. FMF is an autosomal recessive disease, which affects populations from Mediterranean origin and is associated with MEFV gene mutations encoding for the protein pyrin. Pyrin activation enhances the secretion of interleukin 1 by myelo-monocytic cells. Main features of the disease are acute attacks of serositis mainly located on the abdomen, less frequently on chest and joints, accompanied by fever and biological inflammatory markers elevation. Usually attacks last 1 to 3 days and spontaneously stop. A daily oral colchicine intake of 1 to 2mg/day is able to prevent attack's occurrence, frequency, intensity and duration among most patients. Colchicine is also able to prevent the development of inflammatory amyloidosis, the most severe complication of FMF. This state of the art article will focus on the diagnosis of FMF, the treatment and an update on the pathophysiology including the recent described dominant form of MEFV-associated new auto-inflammatory diseases.

Neither hereditary periodic fever nor periodic fever, aphthae, pharingitis, adenitis: Undifferentiated periodic fever in a tertiary pediatric center

AIM

To describe the frequency and clinical characteristics of patients with undifferentiated periodic fever (UPF) and to investigate whether a clinical classification of UPF based on the PRINTO-Eurofever score can help predicting the response to treatment and the outcome at follow-up.

METHODS

Clinical and therapeutic information of patients with recurrent fever who presented at a single pediatric rheumatology center from January 2006 through April 2016 were retrospectively collected. Patients with a clinical suspicion of hereditary periodic fever (HPF) syndrome and patients with clinical picture of periodic fever, aphthae, pharingitis, adenitis (PFAPA) who were refractory to tonsillectomy underwent molecular analysis of five HPF-related genes: MEFV (NM_000243.2), MVK (NM_000431.3), TNFRSF1A (NM_001065.3), NLRP3 (NM_001079821.2), NLRP12 (NM_001277126.1). All patients who had a negative genetic result were defined as UPF and further investigated. PRINTO-Eurofever score for clinical diagnosis of HPF was calculated in all cases.

RESULTS

Of the 221 patients evaluated for periodic fever, twelve subjects with a clinical picture of PFAPA who were refractory to tonsillectomy and 22 subjects with a clinical suspicion of HPF underwent genetic analysis. Twenty-three patients (10.4%) resulted negative and were classified as UPF. The median age at presentation of patients with UPF was 9.5 mo (IQR 4-24). Patients with UPF had a higher frequency of aphthae (52.2% vs 0%, P = 0.0026) and musculoskeletal pain (65.2% vs 18.2%, P = 0.0255) than patients with genetic confirmed HPF. Also, patients with UPF had a higher frequency of aphthous stomatitis (52.2% vs 10.7%, P < 0.0001), musculoskeletal pain (65.2% vs 8,0%, P < 0.0001), and abdominal pain (52.2% vs 4.8%, P < 0.0001) and a lower frequency of pharyngitis (56.6% vs 81.3%, P = 0.0127) compared with typical PFAPA in the same cohort. Twenty-one of 23 patients with UPF (91.3%) received steroids, being effective in 16; 13 (56.2%) were given colchicine, which was effective in 6. Symptoms resolution occurred in 2 patients with UPF at last follow-up. Classification according to the PRINTO-Eurofever score did not correlate with treatment response and prognosis.

CONCLUSION

UPF is not a rare diagnosis among patients with periodic fever. Clinical presentation place UPF half way on a clinical spectrum between PFAPA and HPF. The PRINTO-Eurofever score is not useful to predict clinical outcome and treatment response in these patients.

Familial Mediterranean fever mutations are hypermorphic mutations that specifically decrease the activation threshold of the Pyrin inflammasome

Objectives

FMF is the most frequent autoinflammatory disease and is associated in most patients with bi-allelic MEFV mutations. MEFV encodes Pyrin, an inflammasome sensor activated following RhoGTPase inhibition. The functional consequences of MEFV mutations on the ability of Pyrin variants to act as inflammasome sensors are largely unknown. The aim of this study was to assess whether MEFV mutations affect the ability of Pyrin to detect RhoGTPase inhibition and other inflammasome stimuli.

Methods

IL-1β and IL-18 released by monocytes from healthy donors (HDs) and FMF patients were measured upon specific engagement of the Pyrin, NLRP3 and NLRC4 inflammasomes. Cell death kinetics following Pyrin activation was monitored in real time.

Results

Monocytes from FMF patients secreted significantly more IL-1β and IL-18 and died significantly faster than HD monocytes in response to low concentrations of Clostridium difficile toxin B (TcdB), a Pyrin-activating stimulus. Monocytes from patients bearing two MEFV exon 10 pathogenic variants displayed an increased Pyrin inflammasome response compared with monocytes from patients with a single exon 10 pathogenic variant indicating a gene-dosage effect. Using a short priming step, the response of monocytes from FMF patients to NLRP3- and NLRC4-activating stimuli was normal indicating that MEFV mutations trigger a specific hypersensitivity of monocytes to low doses of a Pyrin-engaging stimulus.

Conclusion

Contrary to the NLRP3 mutations described in cryopyrin-associated periodic syndrome, FMF-associated MEFV mutations do not lead to a constitutive activation of Pyrin. Rather, FMF-associated mutations are hypermorphic mutations that specifically decrease the activation threshold of the Pyrin inflammasome without affecting other canonical inflammasomes.

Does thiol-disulphide balance show oxidative stress in different MEFV mutations?

Many studies have shown that oxidative stress levels increase in patients with Familial Mediterranean Fever (FMF). Thiols are a class of compounds that include a sulfhydryl group (-SH) and can react with free oxygen radicals to protect tissues. We aimed to investigate thiol-disulphide homeostatic status in FMF patients and examined the effect of different mutations in the MEFV gene on the thiol-disulphide balance. We investigated thiol-disulphide parameters in patients with FMF and healthy controls. To determine the differential effect of MEFV gene mutations on thiol-disulphide balance, subjects were divided into five groups based on homozygous or compound heterozygous exon 10 and nonexon 10 mutations. Tests of thiol-disulphide homeostasis were conducted using the automated spectrophotometric method. Patients with FMF had significantly lower native thiol [433.8 µmol/l (243.3-536.4) vs. 484.1 µmol/L (340.2-612.3), p  < 0.001], total thiol levels [459.7 µmol/L (281.3-575.4) vs. 529.9 µmol/L (363-669.5), p < 0.001], and disulphide levels [14.0 µmol/l (2.7-33.3) vs. 24.4 µmol/l (7.2-36.6), p < 0.001] compared to the control group. Moreover, disulphide/native thiol (3.4 ± 1.7 vs. 4.7 ± 1.3, p < 0.001) and disulphide/total thiol (3.1 ± 1.4 vs. 4.3 ± 1.0 p < 0.001) were also detected lower in the FMF group compared to the control group. But the native thiol/total thiol ratios (93.6 ± 2.9 vs. 91.3 ± 2.1, p < 0.001) were higher in the FMF group. There was no significant difference between the native thiol, total thiol, and disulphide levels of individuals with nonexon 10 homozygous or compound heterozygous (Group 1), nonexon 10-exon 10 compound heterozygous (Group 2), exon 10 homozygous or compound heterozygous (Group 3), and heterozygous (Group 4) mutations. However, these parameters significantly differed from those of the healthy control group. Since no differences were found in our study between thiol and disulfide levels of Groups 1, 2 and 3, we believe that this rate cannot be shown as an indicator of oxidative damage in different mutations of FMFs. To the best of our knowledge, this study is the first study that demonstrates the effect of different FMF mutations on the thiol-disulphide balance.

Efficacy of anakinra in a patient with systemic amyloidosis presenting as amyloidoma

Amyloidosis is a heterogeneous group of disorders characterized by extracellular deposition of unique protein fibrils. The least common presentation of an amyloid deposition is as a discrete mass called amyloidoma or amyloid tumor. We report a case of a soft tissue amyloidoma in the abdomen of a 16-year-old girl who was diagnosed as having systemic amyloidosis. A girl aged 16 years was referred to our hospital with a pre-diagnosis of a retroperitoneal mass documented with abdominal ultrasonography and tomography. A laboratory examination revealed nephrotic syndrome. She underwent surgery for a complete resection of the lesion. A histopathologic examination with Congo red and crystal violet dyes verified the diagnosis of amyloidoma. An immunohistochemical study for amyloid A protein was positive. A renal biopsy was also compatible with AA amyloidosis. A detailed search for the etiology of systemic amyloidosis revealed heterozygous mutation in the Mediterranean fever gene. Treatment with colchicine and anakinra were started with the diagnosis of familial Mediterranean fever because the other causes of secondary amyloidosis were ruled out. After 3 months of anakinra treatment, the laboratory findings returned to normal and excessive proteinuria disappeared. In countries where FMF and other autoinflammatory diseases are prevelant, systemic amyloidosis should be kept in mind in the differential diagnosis of children who present with nephrotic syndrome and abdominal mass. Taking previously reported cases and our case together, it appears that anti-interleukin-1 treatment represents a promising new approach in a subset of patients with systemic amyloidosis secondary to autoinflammatory diseases.

A web-based collection of genotype-phenotype associations in hereditary recurrent fevers from the Eurofever registry

Background

Hereditary recurrent fevers (HRF) are a group of rare monogenic diseases leading to recurrent inflammatory flares. A large number of variants has been described for the four genes associated with the best known HRF, namely MEFV, NLRP3, MVK, TNFRSF1A. The Infevers database (http://fmf.igh.cnrs.fr/ISSAID/infevers) is a large international registry collecting variants reported in these genes. However, no genotype-phenotype associations are provided, but only the clinical phenotype of the first patient(s) described for each mutation. The aim of this study is to develop a registry of genotype-phenotype associations observed in patients with HRF, enrolled and validated in the Eurofever registry.

Results

Genotype-phenotype associations observed in all the patients with HRF enrolled in the Eurofever registry were retrospectively analyzed. For autosomal dominant diseases (CAPS and TRAPS), all mutations were individually analyzed. For autosomal recessive diseases (FMF and MKD), homozygous and heterozygous combinations were described. Mean age of onset, disease course (recurrent or chronic), mean duration of fever episodes, clinical manifestations associated with fever episodes, atypical manifestations, complications and response to treatment were also studied.

Data observed in 751 patients (346 FMF, 133 CAPS, 114 MKD, 158 TRAPS) included in the Eurofever registry and validated by experts were summarized in Tables. A total of 149 variants were described: 46 TNFRSF1A and 27 NLRP3 variants, as well as various combinations of 48 MVK and 28 MEFV variants were available.

Conclusions

We provide a potentially useful tool for physicians dealing with HRF, namely a registry of genotype-phenotype associations for patients enrolled in the Eurofever registry. This tool is complementary to the Infevers database and will be available at the Eurofever and Infevers websites.

Monogenic autoinflammatory diseases: General concepts and presentation in adult patients

Monogenic autoinflammatory diseases (AIFD) are rare disorders characterized by an uncontrolled increase of the systemic inflammatory response, which is caused by mutations in genes involved in inflammatory pathways. Over the last few years, new genes and proteins responsible for new monogenic AIFD have been identified and a substantial improvement in their treatment has been achieved. Monogenic AIFD manifestations typically begin during childhood, but they can also occur in adults. Compared to pediatric patients, adults usually present with a less severe disease and fewer long-term complications. In addition, patients with adult-onset disease carry low-penetrance mutations more often than pathogenic variants. A late-onset of AIFD may be occasionally associated with the presence of somatic mutations. In this study, we review the most frequent monogenic AIFD, and others recently described, which may occur during adulthood.

Monogenic Periodic Fever Syndromes: Treatment Options for the Pediatric Patient

Autoinflammatory diseases are disorders of the innate immune system characterized by uncontrolled inflammation. The most commonly encountered autoinflammatory diseases are the hereditary periodic fever syndromes, which present with fever and other features of the skin, serosal membranes, and musculoskeletal system. The main inherited (monogenic) periodic fever syndromes are familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), tumor necrosis factor receptor-associated periodic syndrome (TRAPS), and hyperimmunoglobulin D syndrome (HIDS)/mevalonate kinase deficiency (MKD). Recent advances in our understanding of the molecular and pathophysiological basis of autoinflammatory diseases have provided new treatment strategies. Patients with periodic fever syndromes have clearly benefited from anti-interleukin (IL)-1 treatment. Colchicine is still the mainstay of FMF therapy, but IL-1 blockade is also effective if colchicine fails. Early diagnosis and effective treatment can prevent irreversible organ damage. The scope of pathogenic mutations and more targeted therapy for better management of these rare diseases remains to be defined.

Evidence of digenic inheritance in autoinflammation-associated genes

Familial Mediterranean fever (FMF) has traditionally been considered as a monogenic autosomal recessive disorder caused by mutations in the MEFV gene with highest incidence among Mediterranean populations. In a considerable number of patients with typical FMF, only one MEFV mutation was identified and the possibility that more than one autoinflammatory gene may be responsible for their disease was investigated. In the present study, an extensive search for possible mutations in three hereditary recurrent fever (HRF) genes was performed in 128 MEFV heterozygous Greek-Cypriots clinically diagnosed based on their phenotype with FMF-like disease from a previous study. Sequence analysis was performed for MVK, TNFRSF1A and NLRP3 genes which is also known to cause HRFs. In total, three patients were identified with heterozygous mutations and a second mutation in an autoinflammatory gene. Two patients carried a MEFV mutation and a NLRP3 mutation, and an additional third carried a MEFV mutation and a TNFRSF1A mutation. Patient 1 carried MEFV p.[Val726Ala] (NM_000243.2:c.2177T>C) and NLRP3 p.[Val198Met] (NM_001243133.1:c.592G>A) variants and patient 2 carried MEFV p.[Glu148Gln] (NM_000243.2:c.442G>C) variant which is of uncertain significance and NLRP3 p.[Arg176Trp] (NM_001243133.1:c.526C>T). Lastly, patient 3 was identified to carry MEFV p.[Met694Val] (NM_000243.2:c.2080A>G) and TNFRSF1A p.[Arg121Gln] (NM_001065.3:c.362G>A) variants. The results from this study indicate that screening of genes known to cause HRFs in patients already identified with a single MEFV mutation, can reveal quite rare but potentially causative mutational combinations at different loci. Such interaction provide further evidence for possible locus-locus interactions and phenotypes resulting from digenic inheritance.

Disease Phenotype and Outcome Depending on the Age at Disease Onset in Patients Carrying the R92Q Low-Penetrance Variant in TNFRSF1A Gene

Background

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is an autosomal-dominant autoinflammatory disease caused by mutations in the TNFRSF1A gene. R92Q, a low-penetrance variant, is usually associated with a milder TRAPS phenotype than structural or pathogenic mutations. No studies differentiating R92Q-related disease in patients with pediatric and adult onset have been performed to date.

Objective

To analyze clinical features and disease outcomes in patients diagnosed with TRAPS associated with R92Q variant and to investigate differences between patients with pediatric and adult disease onset.

Methods

A retrospective review of patients with R92Q-related disease from four reference centers for autoinflammatory diseases was performed. Clinical and laboratory features, family history of autoinflammatory diseases, treatments received, and outcomes during follow-up were recorded and separately analyzed in pediatric and adult patients. Our results were included in the analysis with other reported pediatric and adult R92Q-related disease series.

Results

Our series encompassed 18 patients (9 females and 9 males) with R92Q variant. In 61% of patients, disease onset occurred during infancy and in 39%, during adulthood, with a median diagnostic delay of 5 years and a follow-up of 5.4 years. A positive family history of autoinflammatory disease was detected in 28% of patients. All patients presented with febrile recurrent episodes. Other common symptoms included arthralgia/arthritis (61%), myalgia (39%), asthenia/fatigue (44%), abdominal pain (39%), headache (33%), odynophagia (33%), skin rash (28%), and chest pain (22%). During attacks, 80% of patients increased acute phase reactants levels. No patient had developed amyloidosis during the study period. At the end of follow-up, 28% of patients were asymptomatic and treatment free, 50% were receiving non-steroidal anti-inflammatory drugs or glucocorticoids on demand, and 22% were being treated with biologic agents. When differences between pediatric and adult patients were globally analyzed, adults tended to have longer attacks duration and presented more frequently with chest pain and headache, while abdominal pain, vomiting, cervical adenitis, and pharyngitis predominated in pediatric patients. No differences in outcomes and treatment requirements were observed in both age groups.

Conclusion

This study has contributed to characterize R92Q-related disease by identifying trends in disease phenotypes depending on the age at disease onset.

Familial Mediterranean Fever: Recent Developments in Pathogenesis and New Recommendations for Management

Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease (AID) affecting mainly the ethnic groups originating from Mediterranean basin. The disease is characterized by self-limited inflammatory attacks of fever and polyserositis along with elevated acute phase reactants. FMF is inherited autosomal recessively; however, a significant proportion of heterozygotes also express the phenotype. FMF is caused by mutations in the MEFV gene coding for pyrin, which is a component of inflammasome functioning in inflammatory response and production of interleukin-1β (IL-1β). Recent studies have shown that pyrin recognizes bacterial modifications in Rho GTPases, which results in inflammasome activation and increase in IL-1β. Pyrin does not directly recognize Rho modification but probably affected by Rho effector kinase, which is a downstream event in the actin cytoskeleton pathway. Recently, an international group of experts has published the recommendations for the management of FMF. Colchicine is the mainstay of FMF treatment, and its regular use prevents attacks and controls subclinical inflammation in the majority of patients. Furthermore, it decreases the long-term risk of amyloidosis. However, a minority of FMF patients fail to response or tolerate colchicine treatment. Anti-interleukin-1 drugs could be considered in these patients. One should keep in mind the possibility of non-compliance in colchicine-non-responders. Although FMF is a relatively well-described AID and almost 20 years has passed since the discovery of the MEFV gene, there are still a number of unsolved problems about it such as the exact mechanism of the disease, symptomatic heterozygotes and their treatment, and the optimal management of colchicine resistance.

Longterm Beneficial Effect of Canakinumab in Colchicine-resistant Familial Mediterranean Fever

Objective.

To assess the efficacy and safety of the interleukin-1β (IL-1β) inhibitor canakinumab in all adolescent and adult patients with familial Mediterranean fever (FMF) identified from the Greek National Registry for off-label drug use between 2010 and 2015.

Methods.

In this retrospective longitudinal outcome study, clinical and laboratory data were collected from 14 patients (7 men) aged median 38.5 years (range 13–70), with median disease duration of 14 years, and active FMF despite colchicine (n = 9) or both colchicine and anakinra (n = 5).

Results.

All patients continued to receive canakinumab at last visit (median of 18 mos, range 13–53), which was initially given as monotherapy (n = 8) or in combination with colchicine and/or corticosteroids, every 4 (n = 7), 6 (n = 2), or 8 weeks (n = 5). Eleven patients (79%), including 6 receiving monotherapy, achieved complete clinical remission within 2 months (median), while normalization of all laboratory variables denoting inflammation occurred in 92% at 3 months (median). The remaining 3 patients achieved partial responses. Responses were sustained in all but 4 patients, who relapsed. Reducing the canakinumab administration interval from 8 or 6 weeks to 4 weeks led to suppression of disease activity in the relapsing patients. On the other hand, drug administration interval could be safely increased in 2 patients in remission. Corticosteroid doses were significantly reduced during followup. Canakinumab was well tolerated; 1 patient experienced a urinary tract infection and another one a viral gastroenteritis.

Conclusion.

Treatment with canakinumab in an individualized dosing scheme results in rapid and sustained remission in colchicine-resistant FMF.

Review of autoinflammatory diseases, with a special focus on periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome

There have been remarkable developments in the field of autoinflammatory diseases over the last 20 years. Research has led to definitions of new conditions, increased understanding of disease mechanisms and specific treatment. The polygenic autoinflammatory condition of periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) is the most common autoinflammatory disorder among children in many parts of the world. The clinical features often include clockwork regularity of episodes, prompt responses to corticosteroids and therapeutic effects of tonsillectomy, but the disease mechanisms are largely unknown.

Conclusion

This review discusses the emerging understanding of autoinflammatory diseases, with special emphasis on PFAPA.

Discontinuing colchicine in symptomatic carriers for MEFV (Mediterranean FeVer) variants

Familial Mediterranean fever (FMF) is inherited autosomal recessively; however, heterozygotes may express FMF phenotype. We aimed to define the characteristics of FMF patients heterozygous for MEFV (MEditerranean FeVer) mutations in whom colchicine was stopped after a period of treatment, with close follow-up. We reviewed the charts of 182 children who were heterozygous for MEFV variants. We excluded the patients (n = 34) heterozygous for MEFV variants of unknown significance and patients with typical periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis syndrome (n = 2). All patients were followed up with their routine analysis and serum amyloid A levels every 6 months while on colchicine treatment and every 3-6 months thereafter. MEFV gene variant analysis was performed with Sanger sequencing. Twenty-two out of 146 heterozygotes initially had FMF phenotype, but colchicine was discontinued after a treatment period. The most common MEFV variant was M694V (86.3 %). The median age at diagnosis/initiation of colchicine was 76 (24-144) months. The median duration of colchicine treatment was 36 (24-110) months. The median age at colchicine cessation was 120 (55-172) months. At the time of colchicine cessation, the median attack- and inflammation-free period was 27 (24-84) months. The median follow-up after colchicine cessation was 22.5 (6-102) months. We re-started colchicine in only two patients because of recurrence of symptoms. Individuals with one mutation only can display FMF phenotype and require colchicine for the clinical and laboratory inflammation. However, in some of these patients, colchicine may be discontinued with very careful follow-up.

Familial Mediterranean fever patients homozygous for E148Q variant may have milder disease

AIM

Familial Mediterranean fever (FMF) results from MEFV gene mutations. E148Q is a variant of unknown significance in MEFV. We aimed to define characteristics of FMF patients homozygous for E148Q, check for other MEFV variants in a subgroup, and compare the characteristics with FMF patients carrying other mutations.

METHODS

Thirty FMF patients homozygous for E148Q were reviewed. MEFV variant analysis was performed with strip assay. All MEFV exons were screened by direct DNA sequencing in 14 randomly selected E148Q/E148Q patients. E148Q was also checked in 100 healthy adolescents. We compared the characteristics of FMF patients between three groups: E148Q/E148Q (n = 30), M694V/E148Q (n = 19) and exon 10/exon 10 MEFV mutations (n = 48).

RESULTS

Among 30 FMF patients (E148Q/E148Q), the median age at disease onset and diagnosis were 60 (12-168) and 94 (41-196) months, respectively. Fifteen (50%) patients had mild, 14 (46.7%) moderate and one (3.3%) had severe disease. Twenty-two (73.3%) patients had complete, seven (23.3%) had incomplete response to colchicine, while only one was unresponsive. The detected MEFV variants in 14 E148Q/E148Q FMF patients were as follows: R314R (n = 9; 64.3%), E474E (n = 13; 92.9%), Q476Q (n = 13; 92.9%), D510D (n = 13; 92.9%), and P588P (n = 8; 57.1%). The E148Q allele frequency was 6.5% in healthy adolescents. When compared to FMF patients with other MEFV mutations, disease onset was later, disease was less severe and the ratio of patients responding completely to colchicine was higher in E148Q/E148Q patients.

CONCLUSION

Patients homozygous for E148Q and negative for other pathogenic MEFV variants may display FMF phenotype and may experience moderate/severe disease activity, although the disease may be milder when compared to FMF patients with other mutations.

Distribution of MEFV gene mutations and R202Q polymorphism in the Serbian population and their influence on oxidative stress and clinical manifestations of inflammation

BACKGROUND

The Mediterranean fever (MEFV) gene codes for protein pyrin, one of the regulators of inflammasome activity in innate immune cells. Mutations in this gene are considered the primary cause of Familial Mediterranean fever, but are also found in other monogenic and multifactorial autoinflammatory diseases. The aim of the study was to determine if healthy carriers of MEFV gene mutations and R202Q polymorphism have clinical manifestations of inflammation and impaired oxidative stress parameters.

METHODS

One hundred DNA samples from healthy volunteers (13.3 ± 8.87 years of age (mean ± SD); range 2-35) were sequenced by ABI PRISM 310 automated sequencer (PE Applied Biosystems, Norwalk, USA). The Eurofever questionnaire was used to collect retrospectively medical history data. Oxidative stress was determined by measuring spectrophotometrically thiobarbituric acid reactive substances (TBARS) in plasma and erythrocytes, as well as advanced oxidation protein products in plasma. Superoxide dismutase (SOD) activity was determined by McCord and Fridovich method in plasma and erythrocytes, while the catalase erythrocyte activity was assessed using a catalase ELISA kit.

RESULTS

We found heterozygous carriers of K695R/N mutations in 5 %, E148Q/N mutations in 6 %, R202Q homozygous polymorphism in 10 % and heterozygous R202Q alterations in 45 % of healthy volunteers. The MEFV mutation carriers and R202Q polymorphism homozygotes reported significantly more often recurrent febrile episodes (p = 0.009), diffuse abdominal pain (p = 0.025), and malaise (p = 0.012) compared to non-carriers. Erythrocyte TBARS levels and plasma SOD activity were higher in persons with MEFV mutations and R202Q/R202Q (p = 0.03 and p = 0.049, respectively).

CONCLUSIONS

Healthy individuals may bear E148Q and K695R MEFV gene mutations, as well as R202Q polymorphism in homozygous state. The determined gene alterations contribute to a subtle oxidative stress and may be associated with more frequent episodes of fever and unspecific inflammatory manifestations. An incomplete penetrance or variable expressivity of R202Q in populations of different ethnicity could influence the expression of autoinflammatory diseases phenotype.

Identification of a Novel NLRP12 Nonsense Mutation (Trp408X) in the Extremely Rare Disease FCAS by Exome Sequencing

Familial cold autoinflammatory syndrome (FCAS) is an extremely rare autosomal dominant inherited disease. Although there are four genes that have been linked with FCAS, its molecular diagnosis has been challenging in a relatively large proportion of cases. In this study, we aimed to investigate the genetic defect of a recruited FCAS family using exome sequencing followed by in-depth bioinformatics analysis. As a result, a novel heterozygous stop-gain mutation (Trp408X) in NLRP12 was identified in autosomal dominant inherited FCAS with clinical features of recurrent fever and skin urticaria due to cold conditions. When combined with previous studies, all of the reported mutations were found to have occurred in a highly conserved region in the NACHT domain coding sequence in NLRP12 exon 3, suggesting that a screening strategy for FCAS should focus on this area of the gene. In conclusion, this study demonstrates the importance of exome sequencing for clinical diagnosis of genetic disorders and provides molecular insight into FCAS treatment and diagnosis.

Clinical Characteristics of Patients Carrying the Q703K Variant of the NLRP3 Gene: A 10-year Multicentric National Study

Objective.

The aim of our study was to analyze the clinical and functional effect of the p.Q703K (p. Q705K, c. 2107C>A) variant of the NLRP3 gene in a population of patients screened for suspected cryopyrin-associated periodic syndrome (CAPS).

Methods.

Since 2002, 580 patients underwent molecular analysis for NLRP3. Data on clinical presentation, response to treatment, and longterm followup were collected using a uniform questionnaire. The pattern of cytokine secretion after lipopolysaccharide stimulation from isolated monocytes was analyzed in 3 patients carrying the p.Q703K variant and 1 patient with a chronic infantile neurologic, cutaneous, articular syndrome phenotype carrying both the p.M406I and p.Q703K, and compared with 7 patients with CAPS with sure pathogenic variants and 6 healthy controls.

Results.

The p.Q703K variant was found in 57 screened patients with an overall allelic frequency of 5%. The frequency in normal controls was 5.5%. Clinical data at the moment of molecular analysis and at followup were available in 36 patients. Two patients displayed additional mutations of NLRP3. The mean followup was 2.5 years. Thirteen patients (39%) had a final diagnosis different from the original suspicion of CAPS. The remaining 21 patients displayed a mild phenotype mainly characterized by recurrent episodes of urticarial rash and arthralgia. Only 8 patients were treated with anti-interleukin (IL)-1 treatment, with a complete response in 5 patients. The pattern of secretion of IL-1β and other cytokines (IL-6 and IL-1 receptor antagonist) in patients did not display the aberrancies observed in patients with CAPS and was similar to that observed in healthy controls.

Conclusion.

The present study confirms the weak clinical and functional effect of the p.Q703K variant.

Perinatal manifestation of mevalonate kinase deficiency and efficacy of anakinra

BACKGROUND

Mevalonate kinase deficiency is a metabolic autoinflammatory syndrome caused by mutations in the MVK gene, mevalonate kinase, the key enzyme in the non-sterol isoprenoid biosynthesis pathway. Two phenotypes of mevalonate kinase deficiency are known based on the level of enzymatic deficiency, mevalonic aciduria and hyperimmunoglobulinemia D syndrome, but a wide spectrum of intermediate phenotypes has been reported. Currently one of the most effective treatments is biological therapy (with interleukin-1 antagonist anakinra or tumour necrosis factor-α inhibitor etanercept).

CASE PRESENTATION

The patient in this case has a phenotype contributing to a severe disease that caused the symptoms to manifest very early, in the prenatal period. Mevalonate kinase deficiency was suspected on the basis of clinical (hydrops fetalis, hepatosplenomegaly, hypotonia) and laboratory signs (anaemia, intense acute phase reaction, increased urinary excretion of mevalonic acid). Mutation analysis of the MVK gene confirmed the biochemical diagnosis. Treatment with the interleukin-1 antagonist anakinra was started (minimal dose of 1 mg/kg/day) and revealed its efficacy after three days.

CONCLUSIONS

Our case highlights the need for a very detailed clinical and laboratory assessment in new-borns with any suggestion of autoinflammatory disorders. It is important that patients are diagnosed as early as possible to provide better multidisciplinary follow-up and therapy when needed.

Familial Mediterranean fever: current perspectives

Familial Mediterranean fever (FMF) is the most frequent monogenic autoinflammatory disease, and it is characterized by recurrent attacks of fever and polyserositis. The disease is associated with mutations in the MEFV gene encoding pyrin, which causes exaggerated inflammatory response through uncontrolled production of interleukin 1. The major long-term complication of FMF is amyloidosis. Colchicine remains the principle therapy, and the aim of treatment is to prevent acute attacks and the consequences of chronic inflammation. With the evolution in the concepts about the etiopathogenesis and genetics of the disease, we have understood that FMF is more complicated than an ordinary autosomal recessive monogenic disorder. Recently, recommendation sets have been generated for interpretation of genetic testing and genetic diagnosis of FMF. Here, we have reviewed the current perspectives in FMF in light of recent recommendations.

EULAR recommendations for the management of familial Mediterranean fever

Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease, but many rheumatologists are not well acquainted with its management. The objective of this report is to produce evidence-based recommendations to guide rheumatologists and other health professionals in the treatment and follow-up of patients with FMF. A multidisciplinary panel, including rheumatologists, internists, paediatricians, a nurse, a methodologist and a patient representative, was assembled. Panellists came from the Eastern Mediterranean area, Europe and North America. A preliminary systematic literature search on the pharmacological treatment of FMF was performed following which the expert group convened to define aims, scope and users of the guidelines and established the need for additional reviews on controversial topics. In a second meeting, recommendations were discussed and refined in light of available evidence. Finally, agreement with the recommendations was obtained from a larger group of experts through a Delphi survey. The level of evidence (LoE) and grade of recommendation (GR) were then incorporated. The final document comprises 18 recommendations, each presented with its degree of agreement (0–10), LoE, GR and rationale. The degree of agreement was greater than 7/10 in all instances. The more controversial statements were those related to follow-up and dose change, for which supporting evidence is limited. A set of widely accepted recommendations for the treatment and monitoring of FMF is presented, supported by the best available evidence and expert opinion. It is believed that these recommendations will be useful in guiding physicians in the care of patients with FMF.

Killer Cell Immunoglobulin-Like Receptor (KIR) Genotype Distribution in Familial Mediterranean Fever (FMF) Patients

BACKGROUND Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disease predominantly affecting Mediterranean populations. The gene associated with FMF is the MEFV gene, which encodes for a protein called pyrin. Mutations of pyrin lead to uncontrolled attacks of inflammation, and subclinical inflammation continues during attack-free intervals. Killer cell immunoglobulin-like receptor (KIR) genes encode HLA class I receptors expressed by NK cells. The aim this study was to look for immunogenetic determinants in the pathogenesis of FMF and find out if KIR are related to susceptibility to disease or complications like renal amyloidosis. MATERIAL AND METHODS One hundred and five patients with FMF and 100 healthy individuals were involved in the study. Isolated DNA from peripheral blood was amplified by sequence specific PCR probes and analyzed by Luminex for KIR genotypes. Fisher Exact test was used to evaluate the variation of KIR gene distribution. RESULTS All patients and healthy controls expressed the framework genes. An activator KIR gene, KIR2DS2, was significantly more frequent in FMF patients (p=0.036). Renal amyloidosis and presence of arthritis were not associated with KIR genes and genotype. KIR3DL1 gene was more common in patients with high serum CRP (p=0.016). CONCLUSIONS According to our findings, we suggest that presence of KIR2DS2, which is an activator gene for NK cell functions, might be related to the autoinflammation in FMF. The potential effect of KIR genes on amyloidosis and other clinical features requires studies with larger sample sizes.