Recombinant Interleukin-1 Receptor Antagonist Is an Effective First-Line Treatment Strategy in New-Onset Systemic Juvenile Idiopathic Arthritis, Irrespective of HLA-DRB1 Background and IL1RN Variants.

OBJECTIVE: Human leukocyte antigen (HLA)-DRB1*15:01 has been recently associated with interstitial lung disease (LD), eosinophilia, and drug reactions in systemic juvenile idiopathic arthritis (sJIA). Additionally, genetic variants in IL1RN have been linked to poor response to anakinra. We sought to reproduce these findings in a prospective cohort study of patients with new-onset sJIA treated with anakinra as first-line therapy. METHODS: HLA and IL1RN risk alleles were identified via whole-genome sequencing. Treatment responses and complications were compared between carriers versus noncarriers. RESULTS: Seventeen of 65 patients (26%) carried HLA-DRB1*15:01, comparable with the general population, and there was enrichment for HLA-DRB1*11:01, a known risk locus for sJIA. The rates of clinical inactive disease (CID) at 6 months, 1 year, and 2 years were generally high, irrespective of HLA-DRB1 or IL1RN variants, but significantly lower in carriers of an HLA-DRB1*11:01 allele. One patient, an HLA-DRB1*15:01 carrier, developed sJIA-LD. Of the three patients with severe drug reactions to biologics, one carried HLA-DRB1*15:01. The prevalence of eosinophilia did not significantly differ between HLA-DRB1*15:01 carriers and noncarriers at disease onset (6.2% vs 14.9%, P = 0.67) nor after the start of anakinra (35.3% vs 37.5% in the first 2 years of disease). CONCLUSION: We observed high rates of CID using anakinra as first-line treatment irrespective of HLA-DRB1 or IL1RN variants. Only one of the 17 HLA-DRB1*15:01 carriers developed sJIA-LD, and of the three patients with drug reactions to biologics, only one carried HLA-DRB1*15:01. Although thorough monitoring for the development of drug hypersensitivity and refractory disease courses in sJIA, including sJIA-LD, remains important, our data support the early start of biologic therapy in patients with new-onset sJIA irrespective of HLA-DRB1 background or IL1RN variants.

Developing Entrustable Professional Activities for the Training of Translational Scientists: A Modified Delphi Study.

PURPOSE: Improved training for translational scientists is important to help address the waste of resources and irreproducibility of research outcomes in current translational medicine. However, there are a lack of training programs that cover the full range of knowledge and skills translational scientists need to develop, and many translational research training programs struggle to develop competency frameworks and assessment tools. Entrustable professional activities (EPAs) have been successfully implemented to link competencies with everyday practice in training health care professionals but have not yet been developed for research training. The purpose of the current study was to develop EPAs for translational scientists that could be used for their training and assessment and help increase the transparency and reproducibility of research outcomes and methods by providing best practices for translational research. METHOD: In 2019, a modified Delphi technique, preceded by a focus group held in 2018 using a nominal group technique, was used to reach consensus on EPA titles and content among an international panel of 22 translational experts. Mean, standard deviation, and level of agreement were calculated after each round. Consensus was defined as ≥ 80% agreement. RESULTS: Consensus was reached on 89% of the items after the first round and 100% after the second round. The final list of EPAs consists of 17 EPAs divided over 7 sections. CONCLUSIONS: The concept of EPAs is new to the field of research training. The 17 EPA titles and their descriptions developed in this study may be used as a framework for improved training for translational scientists with the ultimate goal to contribute to closing the gap between bench and bedside, reducing resource waste in science, and increasing the reproducibility of research outcomes.

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.

Treatment to Target Using Recombinant Interleukin-1 Receptor Antagonist as First-Line Monotherapy in New-Onset Systemic Juvenile Idiopathic Arthritis: Results From a Five-Year Follow-Up Study.

OBJECTIVE: Systemic juvenile idiopathic arthritis (JIA) is a multifactorial autoinflammatory disease with a historically poor prognosis. With current treatment regimens, approximately half of patients still experience active disease after 1 year of therapy. This study was undertaken to evaluate a treat-to-target approach using recombinant interleukin-1 receptor antagonist (rIL-1Ra; anakinra) as first-line monotherapy to achieve early inactive disease and prevent damage. METHODS: In this single-center, prospective study, patients with new-onset systemic JIA with an unsatisfactory response to nonsteroidal antiinflammatory drugs received rIL-1Ra monotherapy according to a treat-to-target strategy. Patients with an incomplete response to 2 mg/kg rIL-1Ra subsequently received 4 mg/kg rIL-1Ra or additional prednisolone, or switched to alternative therapy. For patients in whom inactive disease was achieved, rIL-1Ra was tapered after 3 months and subsequently stopped. RESULTS: Forty-two patients, including 12 who had no arthritis at disease onset, were followed up for a median of 5.8 years. The median time to achieve inactive disease was 33 days. At 1 year, 76% had inactive disease, and 52% had inactive disease while not receiving medication. High neutrophil counts at baseline and a complete response after 1 month of rIL-1Ra were highly associated with inactive disease at 1 year. After 5 years of follow-up, 96% of the patients included had inactive disease, and 75% had inactive disease while not receiving medication. Articular or extraarticular damage was reported in <5%, and only 33% of the patients received glucocorticoids. Treatment with rIL-1Ra was equally effective in systemic JIA patients without arthritis at disease onset. CONCLUSION: Treatment to target, starting with first-line, short-course monotherapy with rIL-1Ra, is a highly efficacious strategy to induce and sustain inactive disease and to prevent disease- and glucocorticoid-related damage in systemic JIA.

Microbiome Analytics of the Gut Microbiota in Patients With Juvenile Idiopathic Arthritis: A Longitudinal Observational Cohort Study.

OBJECTIVE: To assess the composition of gut microbiota in Italian and Dutch patients with juvenile idiopathic arthritis (JIA) at baseline, with inactive disease, and with persistent activity compared to healthy controls. METHODS: In a multicenter, prospective, observational cohort study, fecal samples were collected at baseline from 78 Italian and 21 Dutch treatment-naive JIA patients with <6 months of disease duration and compared to 107 geographically matched samples from healthy children. Forty-four follow-up samples from patients with inactive disease and 25 follow-up samples from patients with persistent activity were analyzed. Gut microbiota composition was determined by 16S ribosomal RNA-based metagenomics. Alpha- and ß-diversity were computed, and log ratios of relative abundance were compared between patients and healthy controls using random forest models and logistic regression. RESULTS: Baseline samples from Italian patients showed reduced richness compared to healthy controls (P < 0.001). Random forest models distinguished between Italian patient baseline samples and healthy controls and suggested differences between Dutch patient samples and healthy controls (areas under the curve >0.99 and 0.71, respectively). The operational taxonomic units (OTUs) of Erysipelotrichaceae (increased in patients), Allobaculum (decreased in patients), and Faecalibacterium prausnitzii (increased in patients) showed different relative abundance in Italian patient baseline samples compared to controls after controlling for multiple comparisons. Some OTUs differed between Dutch patient samples and healthy controls, but no evidence remained after controlling for multiple comparisons. No differences were found in paired analysis between Italian patient baseline and inactive disease samples. CONCLUSION: Our findings show evidence for dysbiosis in JIA patients. Only patient/control status, age, and geographic origin appear to be drivers of the microbiota profiles, regardless of disease activity stage, inflammation, and markers of autoimmunity.

In silico validation of the Autoinflammatory Disease Damage Index.

INTRODUCTION: Autoinflammatory diseases can cause irreversible tissue damage due to systemic inflammation. Recently, the Autoinflammatory Disease Damage Index (ADDI) was developed. The ADDI is the first instrument to quantify damage in familial Mediterranean fever, cryopyrin-associated periodic syndromes, mevalonate kinase deficiency and tumour necrosis factor receptor-associated periodic syndrome. The aim of this study was to validate this tool for its intended use in a clinical/research setting. METHODS: The ADDI was scored on paper clinical cases by at least three physicians per case, independently of each other. Face and content validity were assessed by requesting comments on the ADDI. Reliability was tested by calculating the intraclass correlation coefficient (ICC) using an 'observer-nested-within-subject' design. Construct validity was determined by correlating the ADDI score to the Physician Global Assessment (PGA) of damage and disease activity. Redundancy of individual items was determined with Cronbach's alpha. RESULTS: The ADDI was validated on a total of 110 paper clinical cases by 37 experts in autoinflammatory diseases. This yielded an ICC of 0.84 (95% CI 0.78 to 0.89). The ADDI score correlated strongly with PGA-damage (r=0.92, 95% CI 0.88 to 0.95) and was not strongly influenced by disease activity (r=0.395, 95% CI 0.21 to 0.55). After comments from disease experts, some item definitions were refined. The interitem correlation in all different categories was lower than 0.7, indicating that there was no redundancy between individual damage items. CONCLUSION: The ADDI is a reliable and valid instrument to quantify damage in individual patients and can be used to compare disease outcomes in clinical studies.

Prediction of inactive disease in juvenile idiopathic arthritis: a multicentre observational cohort study.

Objectives: To predict the occurrence of inactive disease in JIA in the first 2 years of disease. Methods: An inception cohort of 152 treatment-naïve JIA patients with disease duration <6 months was analysed. Potential predictors were baseline clinical variables, joint US, gut microbiota composition and a panel of inflammation-related compounds in blood plasma. Various algorithms were employed to predict inactive disease according to Wallace criteria at 6-month intervals in the first 2 years. Performance of the models was evaluated using the split-cohort technique. The cohort was analysed in its entirety, and separate models were developed for oligoarticular patients, polyarticular RF negative patients and ANA positive patients. Results: All models analysing the cohort as a whole showed poor performance in test data [area under the curve (AUC): <0.65]. The subgroup models performed better. Inactive disease was predicted by lower baseline juvenile arthritis DAS (JADAS)-71 and lower relative abundance of the operational taxonomic unit Mogibacteriaceae for oligoarticular patients (AUC in test data: 0.69); shorter duration of morning stiffness, higher haemoglobin and lower CXCL-9 levels at baseline for polyarticular RF negative patients (AUC in test data: 0.69); and shorter duration of morning stiffness and higher baseline haemoglobin for ANA positive patients (AUC in test data: 0.72). Conclusion: Inactive disease could not be predicted with satisfactory accuracy in the whole cohort, likely due to disease heterogeneity. Interesting predictors were found in more homogeneous subgroups. These need to be validated in future studies.

The safety of live-attenuated vaccines in patients using IL-1 or IL-6 blockade: an international survey.

BACKGROUND: Withholding live-attenuated vaccines in patients using interleukin (IL)-1 or IL-6 blocking agents is recommended by guidelines for both pediatric and adult rheumatic diseases, since there is a risk of infection in an immune suppressed host. However, this has never been studied. This retrospective, multicenter survey aimed to evaluate the safety of live-attenuated vaccines in patients using IL-1 or IL-6 blockade. METHODS: We contacted physicians involved in the treatment of autoinflammatory diseases to investigate potential cases. Patients were included if a live-attenuated vaccine had been administered while they were on IL-1 or IL-6 blockade. RESULTS: Seventeen patients were included in this survey (7 systemic juvenile idiopathic arthritis (sJIA), 5 cryopyrin associated periodic syndrome (CAPS), 4 mevalonate kinase deficiency (MKD) and 1 familial Mediterranean fever (FMF). Three patients experienced an adverse event, of which two were serious adverse events (a varicella zoster infection after varicella zoster booster vaccination, and a pneumonia after MMR booster). One additional patient had diarrhea after oral polio vaccine. Further, seven patients experienced a flare of their disease, which were generally mild. Eight patients did not experience an adverse event or a flare. CONCLUSION: We have described a case series of seventeen patients who received a live-attenuated vaccine while using IL-1 or IL-6 blocking medication. The findings of this survey are not a reason to adapt the existing guidelines. Prospective trials are needed in order to acquire more evidence about the safety and efficacy before considering adaptation of guidelines.

Reversal of Sepsis-Like Features of Neutrophils by Interleukin-1 Blockade in Patients With Systemic-Onset Juvenile Idiopathic Arthritis.

OBJECTIVE: Neutrophils are the most abundant innate immune cells in the blood, but little is known about their role in (acquired) chronic autoinflammatory diseases. This study was undertaken to investigate the role of neutrophils in systemic-onset juvenile idiopathic arthritis (JIA), a prototypical multifactorial autoinflammatory disease that is characterized by arthritis and severe systemic inflammation. METHODS: Fifty patients with systemic-onset JIA who were receiving treatment with recombinant interleukin-1 receptor antagonist (rIL-1Ra; anakinra) were analyzed at disease onset and during remission. RNA sequencing was performed on fluorescence-activated cell-sorted neutrophils from 3 patients with active systemic-onset JIA and 3 healthy controls. Expression of activation markers, apoptosis, production of reactive oxygen species (ROS), and degranulation of secretory vesicles from neutrophils were assessed by flow cytometry in serum samples from 17 patients with systemic-onset JIA and 15 healthy controls. RESULTS: Neutrophil counts were markedly increased at disease onset, and this correlated with the levels of inflammatory mediators. The neutrophil counts normalized within days after the initiation of rIL-1Ra therapy. RNA-sequencing analysis revealed a substantial up-regulation of inflammatory processes in neutrophils from patients with active systemic-onset JIA, significantly overlapping with the transcriptome of sepsis. Correspondingly, neutrophils from patients with active systemic-onset JIA displayed a primed phenotype that was characterized by increased ROS production, CD62L shedding, and secretory vesicle degranulation, which was reversed by rIL-1Ra treatment in patients who had achieved clinical remission. Patients with a short disease duration had high neutrophil counts, more immature neutrophils, and a complete response to rIL-1Ra, whereas patients with symptoms for >1 month had normal neutrophil counts and an unsatisfactory response to rIL-1Ra. In vitro, rIL-1Ra antagonized the priming effect of IL-1ß on neutrophils from healthy subjects. CONCLUSION: These results strongly support the notion that neutrophils play an important role in systemic-onset JIA, especially in the early inflammatory phase of the disease. The findings also demonstrate that neutrophil numbers and the inflammatory activity of systemic-onset JIA are both susceptible to IL-1 blockade.

Development of the autoinflammatory disease damage index (ADDI).

OBJECTIVES: Autoinflammatory diseases cause systemic inflammation that can result in damage to multiple organs. A validated instrument is essential to quantify damage in individual patients and to compare disease outcomes in clinical studies. Currently, there is no such tool. Our objective was to develop a common autoinflammatory disease damage index (ADDI) for familial Mediterranean fever, cryopyrin-associated periodic syndromes, tumour necrosis factor receptor-associated periodic fever syndrome and mevalonate kinase deficiency. METHODS: We developed the ADDI by consensus building. The top 40 enrollers of patients in the Eurofever Registry and 9 experts from the Americas participated in multiple rounds of online surveys to select items and definitions. Further, 22 (parents of) patients rated damage items and suggested new items. A consensus meeting was held to refine the items and definitions, which were then formally weighted in a scoring system derived using decision-making software, known as 1000minds. RESULTS: More than 80% of the experts and patients completed the online surveys. The preliminary ADDI contains 18 items, categorised in the following eight organ systems: reproductive, renal/amyloidosis, developmental, serosal, neurological, ears, ocular and musculoskeletal damage. The categories renal/amyloidosis and neurological damage were assigned the highest number of points, serosal damage the lowest number of points. The involvement of (parents of) patients resulted in the inclusion of, for example, chronic musculoskeletal pain. CONCLUSIONS: An instrument to measure damage caused by autoinflammatory diseases is developed based on consensus building. Patients fulfilled a significant role in this process.

The human microbiome and juvenile idiopathic arthritis.

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood. The pathogenesis of JIA is thought to be the result of a combination of host genetic and environmental triggers. However, the precise factors that determine one's susceptibility to JIA remain to be unravelled. The microbiome has received increasing attention as a potential contributing factor to the development of a wide array of immune-mediated diseases, including inflammatory bowel disease, type 1 diabetes and rheumatoid arthritis. Also in JIA, there is accumulating evidence that the composition of the microbiome is different from healthy individuals. A growing body of evidence indeed suggests that, among others, the microbiome may influence the development of the immune system, the integrity of the intestinal mucosal barrier, and the differentiation of T cell subsets. In turn, this might lead to dysregulation of the immune system, thereby possibly playing a role in the development of JIA. The potential to manipulate the microbiome, for example by faecal microbial transplantation, might then offer perspectives for future therapeutic interventions. Before we can think of such interventions, we need to first obtain a deeper understanding of the cause and effect relationship between JIA and the microbiome. In this review, we discuss the existing evidence for the involvement of the microbiome in JIA pathogenesis and explore the potential mechanisms through which the microbiome may influence the development of autoimmunity in general and JIA specifically.

The Phenotype and Genotype of Mevalonate Kinase Deficiency: A Series of 114 Cases From the Eurofever Registry.

OBJECTIVE: Mevalonate kinase deficiency (MKD) is a rare metabolic disease characterized by recurrent inflammatory episodes. This study was undertaken to describe the genotype, phenotype, and response to treatment in an international cohort of MKD patients. METHODS: All MKD cases were extracted from the Eurofever registry (Executive Agency for Health and Consumers project no. 2007332), an international, multicenter registry that retrospectively collects data on children and adults with autoinflammatory diseases. RESULTS: The study included 114 MKD patients. The median age at onset was 0.5 years. Patients had on average 12 episodes per year. Most patients had gastrointestinal symptoms (n = 112), mucocutaneous involvement (n = 99), lymphadenopathy (n = 102), or musculoskeletal symptoms (n = 89). Neurologic symptoms included headache (n = 43), cerebellar syndrome (n = 2), and mental retardation (n = 4). AA amyloidosis was noted in 5 patients, almost twice as many as expected from findings in previous cohorts. Macrophage activation syndrome occurred in 1 patient. Patients were generally well between attacks, but 10-20% of the patients had constitutional symptoms, such as fatigue, between fever episodes. Patients with p.V377I/p.I268T compound heterozygosity had AA amyloidosis significantly more often. Patients without a p.V377I mutation more often had severe musculoskeletal involvement. Treatment with nonsteroidal antiinflammatory drugs relieved symptoms. Steroids given during attacks, anakinra, and etanercept appeared to improve symptoms and could induce complete remission in patients with MKD. CONCLUSION: We describe the clinical and genetic characteristics of 114 MKD patients, which is the largest cohort studied so far. The clinical manifestations confirm earlier reports. However, the prevalence of AA amyloidosis is far higher than expected.

Diagnostic Value of Urinary Mevalonic Acid Excretion in Patients with a Clinical Suspicion of Mevalonate Kinase Deficiency (MKD).

OBJECTIVE: In patients suffering from mevalonate kinase deficiency (MKD), the reduced enzyme activity leads to an accumulation of mevalonic acid which is excreted in the urine. This study aims to evaluate the diagnostic value of urinary mevalonic acid measurement in patients with a clinical suspicion of mevalonate kinase deficiency. METHODS: In this single-center, retrospective analysis, all patients in whom both measurement of mevalonic acid and genetic testing had been performed in the preceding 17 years have been included. The presence of two pathogenic MVK mutations or demonstration of decreased enzyme activity was considered to be the gold standard for the diagnosis of MKD. RESULTS: Sixty-one patients were included in this study. Thirteen of them harbored two MVK mutations; twelve of them showed elevated levels of mevalonic acid. Forty-eight patients did not harbor any MVK mutations, yet five of them excreted increased amounts of mevalonic acid. This corresponds to a sensitivity of 92%, a specificity of 90%, a positive predictive value of 71%, and a negative predictive value of 98%. The positive likelihood ratio is 10 and the negative likelihood ratio is 0.09. CONCLUSION: MKD seems very unlikely in patients with a normal mevalonic acid excretion, but it cannot be excluded completely. Further, a positive urinary mevalonic acid excretion still requires MVK analysis to confirm the diagnosis of MKD. Therefore, detection of urinary mevalonic acid should not be mandatory before genetic testing. However, as long as genetic testing is not widely available and affordable, measurement of urinary mevalonic acid is a fair way to select patients for MVK gene analysis or enzyme assay.

Recommendations for the management of autoinflammatory diseases.

: Autoinflammatory diseases are characterised by fever and systemic inflammation, with potentially serious complications. Owing to the rarity of these diseases, evidence-based guidelines are lacking. In 2012, the European project Single Hub and Access point for paediatric Rheumatology in Europe (SHARE) was launched to optimise and disseminate regimens for the management of children and young adults with rheumatic diseases, facilitating the clinical practice of paediatricians and (paediatric) rheumatologists. One of the aims of SHARE was to provide evidence-based recommendations for the management of the autoinflammatory diseases cryopyrin-associated periodic syndromes (CAPS), tumour necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) and mevalonate kinase deficiency (MKD). These recommendations were developed using the European League Against Rheumatism standard operating procedure. An expert committee of paediatric and adult rheumatologists was convened. Recommendations derived from the systematic literature review were evaluated by an online survey and subsequently discussed at a consensus meeting using Nominal Group Technique. Recommendations were accepted if more than 80% agreement was reached. In total, four overarching principles, 20 recommendations on therapy and 14 recommendations on monitoring were accepted with ≥80% agreement among the experts. Topics included (but were not limited to) validated disease activity scores, therapy and items to assess in monitoring of a patient. By developing these recommendations, we aim to optimise the management of patients with CAPS, TRAPS and MKD.

Evidence-based recommendations for genetic diagnosis of familial Mediterranean fever.

Familial Mediterranean fever (FMF) is a disease of early onset which can lead to significant morbidity. In 2012, Single Hub and Access point for pediatric Rheumatology in Europe (SHARE) was launched with the aim of optimising and disseminating diagnostic and management regimens for children and young adults with rheumatic diseases. The objective was to establish recommendations for FMF focusing on provision of diagnostic tools for inexperienced clinicians particularly regarding interpretation of MEFV mutations. Evidence-based recommendations were developed using the European League against Rheumatism standard operating procedure. An expert committee of paediatric rheumatologists defined search terms for the systematic literature review. Two independent experts scored articles for validity and level of evidence. Recommendations derived from the literature were evaluated by an online survey and statements with less than 80% agreement were reformulated. Subsequently, all recommendations were discussed at a consensus meeting using the nominal group technique and were accepted if more than 80% agreement was reached. The literature search yielded 3386 articles, of which 25 were considered relevant and scored for validity and level of evidence. In total, 17 articles were scored valid and used to formulate the recommendations. Eight recommendations were accepted with 100% agreement after the consensus meeting. Topics covered were clinical versus genetic diagnosis of FMF, genotype-phenotype correlation, genotype-age at onset correlation, silent carriers and risk of amyloid A (AA) amyloidosis, and role of the specialist in FMF diagnosis. The SHARE initiative provides recommendations for diagnosing FMF aimed at facilitating improved and uniform care throughout Europe.

Treatment of hereditary autoinflammatory diseases.

PURPOSE OF REVIEW: The purpose of this review is to summarize recent advances in the treatment of the hereditary autoinflammatory diseases, focusing on Familial Mediterranean fever (FMF), tumor necrosis factor receptor-associated periodic syndrome (TRAPS), cryopyrin-associated periodic syndromes (CAPS) and mevalonate kinase deficiency (MKD). We discuss recently published studies and their implications for current patient care and future clinical research. RECENT FINDINGS: Interleukin (IL)-1 blockade is effective in most autoinflammatory conditions. Younger patients require a higher dose per kg of body weight. In FMF, colchicine remains the treatment of choice. Single daily dosing appears adequate. When colchicine fails, IL-1 blockade is effective. In CAPS, the beneficial effect of IL-1 blockade is sustained, and side-effects are limited. There is no evidence that one IL-1 blocker is superior to the other. In TRAPS and MKD, IL-1 blockade appears effective. Some patients have sufficient suppression of inflammatory symptoms with NSAIDs or corticosteroids. SUMMARY: Apart from CAPS and FMF, therapy of autoinflammatory diseases is based on small and retrospective studies. IL-1 blockade appears effective, but larger prospective trials are needed, especially in MKD, TRAPS and colchicine-resistant FMF patients.

Mevalonate kinase deficiency, a metabolic autoinflammatory disease.

Mevalonate kinase deficiency is a rare autosomal recessive inborn error of metabolism with an autoinflammatory phenotype. In this review we discuss its pathogenesis, clinical presentation and treatment. Mutations in both copies of the MVK-gene lead to a block in the mevalonate pathway. Interleukin-1beta mediates the inflammatory phenotype. Shortage of a non-sterol isoprenoid product of the mevalonate pathway, Geranylgeranylpyrophosphate leads to aberrant activation of the small GTPase Rac1, and inflammasome activation. The clinical phenotype ranges widely, depending on the severity of the enzyme defect. All patients show recurrent fevers, lymphadenopathy and high acute phase proteins. Severely affected patients have antenatal disease onset, dysmorphic features, growth retardation, cognitive impairment and progressive ataxia. Diagnosis relies on mutation analysis of the MVK-gene. There is no evidence based therapy. IL-1 blockade is usually effective. Severe cases require allogeneic stem cell transplantation. Targeted therapies are needed.

[DIRA: life-threatening but treatable inherited inflammatory disease]. / DIRA: levensbedreigende, maar behandelbare aangeboren ontstekingsziekte.

Deficiency of interleukin(IL)-1 receptor antagonist (DIRA) is an autosomal recessive inherited inflammatory disease, characterised by pustular skin rash and characteristic osteolytic and hypertrophic bone lesions. If left untreated, the disease may progress to a fatal sepsis with multiple organ failure. The symptoms result from an uncontrolled activity of the pro-inflammatory cytokines IL-1 alpha and IL-1 beta, due to the genetic lacking of the natural antagonist, IL-1 receptor antagonist (IL-1RA). Suppletion of the deficient protein induces rapid complete remission. Two cases from one family, both female neonates, illustrate the fatal natural progression, as well as the course under suppletion of IL-1RA (anakinra). Early recognition of this rare disorder can be life saving.