Biological treatments: new weapons in the management of monogenic autoinflammatory disorders

Long-term safety and effectiveness of canakinumab in patients with monogenic autoinflammatory diseases: results from the interim analysis of the RELIANCE registry

OBJECTIVE

Interim analysis of the RELIANCE registry, an on-going, non-interventional, open-label, multicentre, prospective study evaluating the long-term safety, dosing regimens and effectiveness of canakinumab in patients with cryopyrin-associated periodic syndromes (CAPS), familial Mediterranean fever (FMF), tumour-necrosis factor receptor-associated periodic syndrome (TRAPS) or mevalonate-kinase deficiency (MKD)/hyperimmunoglobulin-D syndrome (HIDS).

METHODS

From September 2017 for patients with CAPS, and June 2018 for patients with FMF, TRAPS or MKD/HIDS, the registry enrolled paediatric (aged ≥2 years) and adult patients (aged ≥18 years) receiving canakinumab as part of their routine medical care. Safety, canakinumab dose, disease activity and quality of life outcome measures were evaluated at baseline and every 6 months until end of study visit.

RESULTS

At the analysis cut-off date (December 2020), 168 patients (91 CAPS, 54 FMF, 16 TRAPS and 7 MKD/HIDS) were enrolled. 85 (50.9%) patients were female and 72 (43.1%) were children (<18 years). The median patient age was 20.0 years (range 2.0-79.0 years). In the CAPS cohort, serious infections and serious adverse drug-reactions were more common in patients receiving higher than the recommended starting dose (SD) of canakinumab. A trend to receive >SD of canakinumab was observed in the pooled population. The majority of patients were reported as having either absent or mild/moderate disease activity (physician's global assessment) from baseline to Month 30, with a stable proportion of patients (~70%) in remission under canakinumab treatment. Patient-reported disease activity (Visual Analogue Scale (VAS), Autoinflammatory Disease Activity Index), fatigue (VAS); markers of inflammation (C-reactive protein, serum amyloid A and erythrocyte sedimentation rate) remained well-controlled throughout.

CONCLUSION

Data from this analysis confirm the long-term safety and effectiveness of canakinumab for the treatment of CAPS, FMF, TRAPS and MKD/HIDS.

Overview of the rarest causes of fever in newborns: handy hints for the neonatologist

Neonatal causes of fever are a major source of concern for clinicians. If fever is combined with organ-specific sterile inflammatory manifestations the suspicion of autoinflammatory disorders should be considered, and the list of such conditions starting in the neonatal period includes chronic infantile neurological cutaneous articular syndrome, mevalonate kinase deficiency, deficiency of the interleukin-1 receptor antagonist, otulipenia, STING-associated vasculopathy with onset in infancy and Blau syndrome. Other causes of noninfectious fever that can rarely occur in newborns are Kawasaki disease, Behçet's disease, and hemophagocytic lymphohistiocytosis. Diagnosis of these exceptionally rare disorders is challenging for neonatologists. An early recognition of these complex diseases might lead to use more specific or rational drugs preventing permanent consequences. This review focuses on the rarest causes of fever occurring in the neonatal age with the aim of portraying many protean clinical pictures associated with fever and reviewing the potential available treatments.

Autoinflammatory syndromes

Autoinflammatory syndromes are a steadily growing group of inflammatory diseases caused by abnormal regulations of the innate immune system. The clinical presentation is multifaceted, but recurrent fever, skin involvement, joint inflammation and other systemic symptoms of inflammation are characteristic. In contrast to classic autoimmune diseases, autoantibodies or specific T cells are not involved in the pathogenesis. In fact, innate immunity plays the most important role in autoinflammation. While activation of the innate immune system is usually self-limiting in healthy individuals, mutations and dysregulation can lead to chronic and excessive activation of innate immune responses and to the development of autoinflammatory diseases.

Ocular manifestations of Blau syndrome

PURPOSE OF REVIEW

This article summarizes the systemic and ocular manifestations of Blau syndrome, its genetic basis, and reviews recently published literature.

RECENT FINDINGS

A large multicenter prospective case series is underway, with 3-year preliminary results indicating the prevalence of uveitis, clinical characteristics and early data on its visual prognosis. Case reports have demonstrated the successful use of newer biologic agents.

SUMMARY

Blau syndrome is an exceedingly rare autoinflammatory disorder with skin, joint and eye manifestations. It is caused by autosomal dominant mutations of the NOD2 protein. Eye involvement is typically a chronic bilateral granulomatous iridocyclitis, often with multifocal choroiditis in the posterior segment. Treatment starts with topical and systemic steroids and often requires antimetabolites or biologic agents.

Persistent Tenosynovitis, Steroid Dependency and a Hyperpigmented Scaly Macular Rash in a Child With Juvenile Idiopathic Arthritis

Blau syndrome is a rare autoinflammatory disease, characterized by granulomatous symmetric arthritis, skin rash and uveitis. It is caused by mutations in the CARD15/NOD2 gene, which is a significant part of innate immunity. We describe the case of a patient with Blau syndrome, initially misdiagnosed as juvenile idiopathic arthritis. Genetic analysis showed R334Q mutation in the NOD2 gene that is known to be linked to Blau syndrome. Our patient was successfully treated with the IL-1β blocking agent canakinumab, with clinical and laboratory remission without any adverse effects. To our knowledge this is one of the rare cases of Blau syndrome successfully treated with canakinumab. After moving abroad, canakinumab was discontinued and she was treated with adalimumab instead. Change in her treatment resulted in a relapse of her disease. Prompt recognition of Blau syndrome and the optimal treatment, are vital for the prevention of severe sequelae such as vision loss and joint deformities. Canakinumab constitutes a promising therapeutic approach for Blau syndrome and requires further investigation.

Phenotype variability of autoinflammatory disorders in the pediatric patient: A pictorial overview

Disruption of innate immunity leading to systemic inflammation and multi-organ dysfunction is the basilar footprint of autoinflammatory disorders (AIDs), ranging from rare hereditary monogenic diseases to a large number of common chronic inflammatory conditions in which there is a simultaneous participation of multiple genetic components and environmental factors, sometimes combined with autoimmune phenomena and immunodeficiency. Whatever their molecular mechanism, hereditary AIDs are caused by mutations in regulatory molecules or sensors proteins leading to dysregulated production of proinflammatory cytokines or cytokine-inducing transcription factors, fever, elevation of acute phase reactants, and a portfolio of manifold inflammatory signs which might occur in a stereotyped manner, mostly with overactivity or misactivation of different inflammasomes. Symptoms might overlap in the pediatric patient, obscuring the final diagnosis of AIDs and delaying the most appropriate treatment. Actually, the fast-paced evolution of scientific knowledge has led to recognize or reclassify an overgrowing number of multifactorial diseases, which share the basic pathogenetic mechanisms with AIDs. The wide framework of classic hereditary periodic fevers, AIDs with prominent skin involvement, disorders of the ubiquitin-proteasome system, defects of actin cytoskeleton dynamics, and also idiopathic nonhereditary febrile syndromes occurring in children is herein presented. Interleukin-1 dependence of these diseases or involvement of other predominating molecules is also discussed.

Current Therapeutic Options for the Main Monogenic Autoinflammatory Diseases and PFAPA Syndrome: Evidence-Based Approach and Proposal of a Practical Guide

Monogenic autoinflammatory diseases are rare conditions caused by genetic abnormalities affecting the innate immunity. Previous therapeutic strategies had been mainly based on results from retrospective studies and physicians' experience. However, during the last years, the significant improvement in their genetic and pathogenic knowledge has been accompanied by a remarkable progress in their management. The relatively recent identification of the inflammasome as the crucial pathogenic mechanism causing an aberrant production of interleukin 1β (IL-1β) in the most frequent monogenic autoinflammatory diseases led to the introduction of anti-IL-1 agents and other biologic drugs as part of the previously limited therapeutic armamentarium available. Advances in the treatment of autoinflammatory diseases have been favored by the use of new biologic agents and the performance of a notable number of randomized clinical trials exploring the efficacy and safety of these agents. Clinical trials have contributed to increase the level of evidence and provided more robust therapeutic recommendations. This review analyzes the treatment of the most frequent monogenic autoinflammatory diseases, namely, familial Mediterranean fever, tumor necrosis factor receptor-associated periodic fever syndrome, hyperimmunoglobulin D syndrome/mevalonate kinase deficiency, and cryopyrin-associated periodic syndromes, together with periodic fever with aphthous stomatitis, pharyngitis, and cervical adenitis syndrome, which is the most common polygenic autoinflammatory disease in children, also occurring in adult patients. Finally, based on the available expert consensus recommendations and the highest level of evidence of the published studies, a practical evidence-based guideline for the treatment of these autoinflammatory diseases is proposed.

Innate immune response in retinal homeostasis and inflammatory disorders

Innate immune cells such as neutrophils, monocyte-macrophages and microglial cells are pivotal for the health and disease of the retina. For the maintenance of retinal homeostasis, these cells and immunosuppressive molecules in the eye actively regulate the induction and the expression of inflammation in order to prevent excessive activation and subsequent tissue damage. In the disease context, these regulatory mechanisms are modulated genetically and/or by environmental stimuli such as damage-associated molecular patterns (DAMPs), and a chronic innate immune response regulates or contributes to the formation of diverse retinal disorders such as uveitis, retinitis pigmentosa, retinal vascular diseases and retinal fibrosis. Here we summarize the recent knowledge regarding the innate immune response in both ocular immune regulation and inflammatory retinal diseases, and we describe the potential of the innate immune response as a biomarker and therapeutic target.

Treating TNF Receptor Associated Periodic Fever Syndrome in End-Stage Renal Failure

Tumor necrosis factor receptor associated periodic syndrome (TRAPS) is a rare monogenic autoinflammatory disease. Its most severe manifestation is secondary amyloidosis. A 44-year-old male presented with nephrotic syndrome. Kidney biopsy was conclusive for secondary amyloidosis. The patient and his children had a history of recurrent febrile periods since infancy. All subjects were positive for a heterozygous variant of the TNFRSF1A gene, confirming TRAPS diagnosis. The patient progressed to end-stage renal failure and developed recurrent pericarditis episodes. He was started on anakinra while on hemodialysis with marked reduction of his serum amyloid A protein (SAA) levels. Meanwhile he received a cadaveric renal transplant and maintains anakinra treatment. Despite renal failure being the most feared complication of AA amyloidosis caused by TRAPS, little data is available about safety of anti-IL-1 treatment in patients with severe kidney failure. The authors report this case of a patient on dialysis treated with anakinra in which no complications were registered. Though amyloidosis is established, the authors believe containing its progression and reducing inflammatory activity can improve patient prognosis and reduce recurrence of amyloidosis in kidney transplant, as has been demonstrated in transplanted patients due to familial Mediterranean fever amyloidosis.

The Presence of Uveitis Is Associated with a Sustained Response to the Interleukin (IL)-1 Inhibitors Anakinra and Canakinumab in Behçet's Disease

Purpose: To identify factors associated with sustained response to interleukin (IL)-1 inhibition among demographic, clinical and therapeutic data in patients with Behçet disease (BD).Methods: BD patients treated with anakinra or canakinumab were enrolled. Patients were divided into two groups according to the clinical response: group 1 included subjects showing a treatment duration of at least 52 weeks and no secondary inefficacy during the first follow-up year; the remaining patients were included in the group 2. Demographic, clinical and therapeutic data were analyzed to identify significant differences between groups.Results: Eighteen patients were included in group 1 and 18 patients in group 2. A better response to IL-1 inhibitors was significantly more common among patients with BD-related uveitis (p = 0.006) and patients with a longer disease duration (p = 0.03).Conclusion: IL-1 blockade is effective in BD, especially in the subset of patients presenting eye involvement and in those with long-lasting disease.

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.

From autoinflammation to autoimmunity: old and recent findings

Autoimmune diseases and autoinflammatory diseases have a number of similar etiopathogenetic and clinical characteristics, including genetic predisposition and recurrent systemic inflammatory flares. The first phase of ADs involves innate immunity: by means of TLRs, autoantigen presentation, B and T cell recruitment and autoantibody synthesis. The second phase involves adaptive immunity, a self-sustaining process in which immune complexes containing nucleic acids and autoantibodies activate self-directed inflammation. The link between autoimmunity and autoinflammation is IL-1ß, which is crucial in connecting the innate immune response due to NLR activation and the adaptive immune responses of T and B cells. In conclusion, although ADs are still considered adaptive immunity-mediated disorders, there is increasing evidence that innate immunity and inflammasomes are also involved. The aim of this review is to highlight the link between the innate and adaptive immune mechanisms involved in autoimmune diseases.

New mosaic tiles in childhood hereditary autoinflammatory disorders

The protean clinical phenotypes of hereditary autoinflammatory disorders (HAID) are caused by abnormal activation of innate immunity and consist of seemingly unprovoked inflammatory flares localized to multiple organs, such as the skin, joints, serosal membranes, gut, and central nervous system. Different mutations in genes implied in activation of the interleukin-1 (IL-1)-structured inflammasome, cytoskeletal signaling and apoptosis contribute to the pathogenesis of different HAID, which mostly start in childhood with self-limited flares unrelated to infectious agents, autoantibody production or autoreactive cells. Though IL-1 remains pivotal in many inflammasome-mediated diseases, other cytokinopathies involving IL-18, nuclear factorκ-B, interferons, and tumor necrosis factor have provided new horizons in the definition of HAID of children: the list of HAID has expanded as a consequence of a better understanding of their pathogenetic molecular mechanisms and also application of new genetic technologies. However, diagnosis of most HAID is clinical and focused on several evidence-based criteria sets: their discrimination remains challenging for unexperienced pediatricians as there are no universally accepted algorithms, and a still relevant number of patients may linger without any clarifying genetic analysis, whose interpretation combined with processing of treatment options should be discussed on a multidisciplinary basis.

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.

Human RELA haploinsufficiency results in autosomal-dominant chronic mucocutaneous ulceration

Badran et al. demonstrate an essential contribution of biallelic RELA expression in protecting stromal and epithelial cells from TNF-mediated cell death in patients with chronic mucocutaneous ulceration.

The treatment of chronic mucocutaneous ulceration is challenging, and only some patients respond selectively to inhibitors of tumor necrosis factor-α (TNF). TNF activates opposing pathways leading to caspase-8–mediated apoptosis as well as nuclear factor κB (NF-κB)–dependent cell survival. We investigated the etiology of autosomal-dominant, mucocutaneous ulceration in a family whose proband was dependent on anti-TNF therapy for sustained remission. A heterozygous mutation in RELA, encoding the NF-κB subunit RelA, segregated with the disease phenotype and resulted in RelA haploinsufficiency. The patients’ fibroblasts exhibited increased apoptosis in response to TNF, impaired NF-κB activation, and defective expression of NF-κB–dependent antiapoptotic genes. Rela^+/− mice have similarly impaired NF-κB activation, develop cutaneous ulceration from TNF exposure, and exhibit severe dextran sodium sulfate–induced colitis, ameliorated by TNF inhibition. These findings demonstrate an essential contribution of biallelic RELA expression in protecting stromal cells from TNF-mediated cell death, thus delineating the mechanisms driving the effectiveness of TNF inhibition in this disease.

Autoinflammatory Diseases in Pediatric Dermatology-Part 2: Histiocytic, Macrophage Activation, and Vasculitis Syndromes

The discovery of new autoinflammatory syndromes and novel mutations has advanced at breakneck speed in recent years. Part 2 of this review focuses on vasculitis syndromes and the group of histiocytic and macrophage activation syndromes. We also include a table showing the mutations associated with these autoinflammatory syndromes and treatment alternatives.

Lung Involvement in Children with Hereditary Autoinflammatory Disorders

Short-lived systemic inflammatory reactions arising from disrupted rules in the innate immune system are the operating platforms of hereditary autoinflammatory disorders (HAIDs). Multiple organs may be involved and aseptic inflammation leading to disease-specific phenotypes defines most HAIDs. Lungs are infrequently involved in children with HAIDs: the most common pulmonary manifestation is pleuritis in familial Mediterranean fever (FMF) and tumor necrosis factor receptor-associated periodic syndrome (TRAPS), respectively caused by mutations in the MEFV and TNFRSF1A genes, while interstitial lung disease can be observed in STING-associated vasculopathy with onset in infancy (SAVI), caused by mutations in the TMEM173 gene. The specific pleuropulmonary diseases may range from sub-clinical abnormalities during inflammatory flares of FMF and TRAPS to a severe life-threatening disorder in children with SAVI.

Systemic and organ involvement in monogenic autoinflammatory disorders: a global review filtered through internists' lens

Monogenic autoinflammatory disorders (AIDs) are rare diseases driven by cytokine-mediated extraordinary sterile inflammation that results from the activation of innate immune pathways. The clinical hallmark of these diseases is the recurrence of stereotyped episodes of systemic- and organ-specific inflammation; the most common systems involved being the skin, musculoskeletal system, gastrointestinal tract, and central nervous system. The autoinflammatory disorders may have a profound impact on the quality of life of the affected patients, and a delayed diagnosis may lead to severe complications, the most dreadful of which is AA-Amyloidosis. This review gives an overview on the four main AIDs, namely familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, cryopyrinopathies, and mevalonate kinase deficiency, focusing on their clinical phenotype in adults and differential diagnosis, suggesting a diagnostic algorithm, and reviewing the available treatments.

Canakinumab reverses overexpression of inflammatory response genes in tumour necrosis factor receptor-associated periodic syndrome

Objective

To explore whether gene expression profiling can identify a molecular mechanism for the clinical benefit of canakinumab treatment in patents with tumour necrosis factor receptor-associated periodic syndrome (TRAPS).

Methods

Blood samples were collected from 20 patients with active TRAPS who received canakinumab 150 mg every 4 weeks for 4 months in an open-label proof-of-concept phase II study, and from 20 aged-matched healthy volunteers. Gene expression levels were evaluated in whole blood samples by microarray analysis for arrays passing quality control checks.

Results

Patients with TRAPS exhibited a gene expression signature in blood that differed from that in healthy volunteers. Upon treatment with canakinumab, many genes relevant to disease pathogenesis moved towards levels seen in the healthy volunteers. Canakinumab downregulated the TRAPS-causing gene (TNF super family receptor 1A (TNFRSF1A)), the drug-target gene (interleukin (IL)-1B) and other inflammation-related genes (eg, MAPK14). In addition, several inflammation-related pathways were evident among the differentially expressed genes. Canakinumab treatment reduced neutrophil counts, but the observed expression differences remained after correction for this.

Conclusions

These gene expression data support a model in which canakinumab produces clinical benefit in TRAPS by increasing neutrophil apoptosis and reducing pro-inflammatory signals resulting from the inhibition of IL-1β. Notably, treatment normalised the overexpression of TNFRSF1A, suggesting that canakinumab has a direct impact on the main pathogenic mechanism in TRAPS.

Trial registration number

NCT01242813.

The Use of IL-1 Receptor Antagonist (Anakinra) in Idiopathic Recurrent Pericarditis: A Narrative Review

Recurrent pericarditis is a complication of acute pericarditis in 20–30% of the patients and is usually idiopathic in nature. The underlying pathogenesis of this condition remains unclear, although immune-mediated mechanisms seem likely. A subgroup of these patients with refractory symptoms can be challenging to manage, and multiple immunosuppressive medications have been used without consistent benefit. Anakinra, an interleukin-1 receptor antagonist, has been used in treatment of rheumatoid arthritis and autoinflammatory syndromes. Preliminary evidence suggests that anakinra could be a promising therapy for idiopathic recurrent pericarditis. In this narrative review, we summarize the current understanding of the etiopathogenesis of idiopathic recurrent pericarditis, mechanism of action of anakinra, and the preliminary evidence, supporting the use of anakinra in pericarditis.

Lights and shadows in autoinflammatory syndromes from the childhood and adulthood perspective

In a high percentage of cases, the monogenic autoinflammatory syndromes (AIS), caused by subversion in the inflammasome homeostasis leading to cytokine oversecretion and characterized by multiple inflammatory pictures, start in childhood. However, the description of tardive manifestations, veiled phenotypes, and atypical clinical signs beginning in adulthood has been more and more reported in recent times, requiring that many specialists become confident with concepts, details, and management strategies of AIS. Differences between child- and adult-onset syndromes raise the question of whether pathogenic mechanisms might differ when the timetable of AIS onset diverges, but show that carefulness is needed to establish a straightforward diagnosis.

Practice parameter for the diagnosis and management of primary immunodeficiency

The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) have jointly accepted responsibility for establishing the "Practice parameter for the diagnosis and management of primary immunodeficiency." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Basic Characteristics of Adults with Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenopathy Syndrome in Comparison with the Typical Pediatric Expression of Disease

Autoinflammatory diseases are caused by inflammasome dysregulation leading to overproduction of proinflammatory cytokines and a pathological delay in the inflammation switching off. The progress of cellular biology has partially clarified pathogenic mechanisms behind monogenic autoinflammatory diseases, whereas little is known about the polygenic ones. Although the genetic susceptibility of periodic fever, aphthous stomatitis, pharyngitis, and adenopathy (PFAPA) syndrome is still obscure, the presence of overlapping symptoms with monogenic periodic fevers, the recurrence in family members, the important role played by dysregulated interleukin- (IL-) 1β secretion during flares, the overexpression of inflammasome-associated genes during attacks, and, last but not least, the therapeutic efficacy of IL-1β blockade strongly indicate a potential genetic involvement in its pathogenesis, probably linked with environmental factors. PFAPA syndrome has a typical inception in the pediatric age, but a delayed onset during adulthood has been described as well. Treatments required as well as effectiveness of tonsillectomy remain controversial, even if the disease seems to have a self-limited course mostly in children. The purpose of this review is to provide an overview of this complex polygenic/multifactorial autoinflammatory disorder in which the innate immune system undoubtedly plays a basic role.

Autoinflammatory granulomatous diseases: from Blau syndrome and early-onset sarcoidosis to NOD2-mediated disease and Crohn's disease

The recent identification of genetic mutations leading to dysfunction of inflammatory and apoptotic pathways, has allowed to characterise a group of diseases, recognised as monogenic autoinflammatory syndromes. Among those, Blau syndrome (BS) and early-onset sarcoidosis (EOS) have been identified as familial and sporadic phenotypes of the same non-caseating granulomatous form. Both the diseases are caused by mutations in the CARD15/NOD2 gene, encoding the cytosolic NOD2 protein, one of the key molecules in the regulation of innate immunity. Clinical onset is typically located in the first years of life and phenotype is characterised by simultaneous or less articular, cutaneous and ocular non-caseating granulomatous inflammation, which can be variably associated with a heterogeneous systemic spectrum. The CARD15/NOD2 gene has also been identified as one of the genes linked to susceptibility to Crohn's disease (CD), a common polygenic inflammatory granulomatous bowel disease. The heightened nuclear factor-κB activity, found in the intestinal tissue of patients affected by CD, has probably a genetic cause related to several CARD15/NOD2 polymorphisms. Other substitutions in the CARD15/NOD2 gene have also been found in a recently described disorder, called NOD2-associated autoinflammatory disease, which shares several clinical characteristics with BS and EOS. This review attempts to describe these diseases on the basis of the most recent evidences. We described genetic and clinical aspects, mainly focusing on BS and EOS, the most representative diseases of autoinflammatory granulomatous diseases, with the ultimate purpose to expand their knowledge.

Canakinumab efficacy and long-term tocilizumab administration in tumor necrosis factor receptor-associated periodic syndrome (TRAPS)

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is an autosomal dominantly inherited autoinflammatory disease caused by mutations in the TNFRSF1A gene. Treatment is aimed at preventing acute disease attacks, improving quality of life, and preventing long-term complications such as systemic reactive amyloidosis. Biologic agents have significantly improved TRAPS management. In particular, interleukin 1 (IL-1) inhibition either with the recombinant IL-1 receptor antagonist anakinra or with the human IgG1 anti-IL-1β monoclonal antibody canakinumab has recently shown to induce a prompt and stable disease remission. Conversely, the successful experience with IL-6 inhibition is nowadays limited to a single patient. Anyway, introduction of new treatment options for patients requiring a lifelong therapy is desirable. We describe two TRAPS patients (son and father) successfully treated with canakinumab and tocilizumab, respectively. In particular, we highlight the clinical and laboratory efficacy as well as the good safety profile of tocilizumab during a 42-month follow-up period.

Republished: new age of biological therapies in paediatric rheumatology

Many paediatric rheumatic diseases result from the abnormal activation or control of the immune system. Biologic drugs, which are synthesised within a biological system, have been designed to target specific molecules involved in cytokine signalling or cell-cell interactions. The past 15 years have seen a revolution in the range of effective treatments for rheumatic diseases, particularly juvenile idiopathic arthritis (JIA). As a result, the target of inactive disease and minimal long-term disease-associated damage is increasingly becoming achievable. In this article we review evidence from recent trials of the use of biologic drugs in the treatment of systemic JIA, juvenile dermatomyositis and juvenile systemic lupus erythematosus. We also highlight novel agents currently undergoing investigation which may broaden our therapeutic armamentarium over the coming decade. Key to these developments are well-designed multicentre controlled clinical trials and long-term safety monitoring as part of international drug registries.

The protean ocular involvement in monogenic autoinflammatory diseases: state of the art

Ocular involvement is frequent in the monogenic autoinflammatory disorders and generally occurs as spontaneously recurring inflammatory events at different ocular sites caused by the aberrant release of proinflammatory cytokines, mainly IL-1β. Over the past decade, we witnessed a significant growth of eye abnormalities associated with idiopathic granulomatous disorders, familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, mevalonate kinase deficiency, and cryopyrin-associated periodic syndrome. The pathogenetic mechanisms of these disorders have shown the evidence of disrupted cytokine signaling, but the explanation for the heterogeneous ocular involvement remains to be elucidated. We herein review the monogenic autoinflammatory disorders affecting the eye, describing their main clinical features with specific regard to the ocular involvement, which can lead to decreased visual acuity and even blindness, if the primary disorder is undetected or left untreated.

Monogenic autoinflammatory diseases: Cytokinopathies

Rapid advances in genetics are providing unprecedented insight into functions of the innate immune system with identification of the mutations that cause monogenic autoinflammatory disease. Cytokine antagonism is profoundly effective in a subset of these conditions, particularly those associated with increased interleukin-1 (IL-1) activity, the inflammasomopathies. These include syndromes where the production of IL-1 is increased by mutation of innate immune sensors such as NLRP3, upstream signalling molecules such as PSTPIP1 and receptors or downstream signalling molecules, such as IL-1Ra. Another example of this is interferon (IFN) and the interferonopathies, with mutations in the sensors STING and MDA5, the upstream signalling regulator AP1S3, and a downstream inhibitor of IFN signalling, ISG15. We propose that this can be extended to cytokines such as IL-36, with mutations in IL-36Ra, and IL-10, with mutations in IL-10RA and IL-10RB, however mutations in sensors or upstream signalling molecules are yet to be described in these instances. Additionally, autoinflammatory diseases can be caused by multiple cytokines, for example with the activation of NF-κB/Rel, for which we propose the term Relopathies. This nosology is limited in that some cytokine pathways may be degenerate in their generation or execution, however provides insight into likely autoinflammatory disease candidates and the cytokines with which newly identified mutations may be associated, and therefore targeted.

Current advances in the understanding and treatment of mevalonate kinase deficiency

Mevalonate kinase deficiency (MKD) is a rare autosomal recessive autoinflammatory metabolic disease that is caused by mutations in the MVK gene. Patients with MKD typically have an early onset in infancy. MKD is characterized by recurrent episodes of high fever, abdominal distress, diffuse joint pain, and skin rashes. In a subset of patients, MKD is also associated with elevated serum immunoglobulin D (IgD) levels (hyperimmunoglobulinemia D syndrome, HIDS). The clinical phenotype of MKD varies widely and depends on the severity of the impaired mevalonate kinase activity. Complete impairment results in the severe metabolic disease, mevalonic aciduria, while a partial deficiency results in a broad spectrum of clinical presentation, including HIDS. The precise molecular mechanisms behind the elevated serum IgD levels and inflammation that occurs in MKD remain unknown. Children who exhibit symptoms of MKD should be tested for mutations in the MKD gene. However, the complexity of MKD often results in delays in its definitive diagnosis and the outcome in adult age is not completely known. Therapeutic options for MKD are based on limited data and include non-steroidal anti-inflammatory drugs, corticosteroids, and biological agents that target specific cytokine pathways. In recent years, some studies have reported promising results for new biological drugs; however, these cases have failed to achieve satisfactory remission. Therefore, further studies are needed to understand the pathogenesis of MKD and identify innovative therapeutic tools for its management.

Interleukin-1 as a common denominator from autoinflammatory to autoimmune disorders: premises, perils, and perspectives

A complex web of dynamic relationships between innate and adaptive immunity is now evident for many autoinflammatory and autoimmune disorders, the first deriving from abnormal activation of innate immune system without any conventional danger triggers and the latter from self-/non-self-discrimination loss of tolerance, and systemic inflammation. Due to clinical and pathophysiologic similarities giving a crucial role to the multifunctional cytokine interleukin-1, the concept of autoinflammation has been expanded to include nonhereditary collagen-like diseases, idiopathic inflammatory diseases, and metabolic diseases. As more patients are reported to have clinical features of autoinflammation and autoimmunity, the boundary between these two pathologic ends is becoming blurred. An overview of monogenic autoinflammatory disorders, PFAPA syndrome, rheumatoid arthritis, type 2 diabetes mellitus, uveitis, pericarditis, Behçet's disease, gout, Sjögren's syndrome, interstitial lung diseases, and Still's disease is presented to highlight the fundamental points that interleukin-1 displays in the cryptic interplay between innate and adaptive immune systems.

Autoimmunity and autoinflammation as the yin and yang of idiopathic recurrent acute pericarditis

Autoimmunity and autoinflammation are generally considered as mutually exclusive mechanisms of diseases but may concur to specific syndromes. Idiopathic recurrent acute pericarditis (IRAP) is defined as the recurrence of pericardial symptoms at any point following the prior cessation of acute pericarditis, and the latency is generally 6 weeks. Manifestations of pericarditis such as pericardial friction rub, electrocardiographic changes, and pericardial effusion are less frequent in the subsequent episodes compared to the index attack, and in some cases the only clinical sign is represented by a suggestive chest pain. Several autoimmune diseases may manifest with pericarditis which is often related to viral infections, while postviral pericarditis may in turn display a nonspecific autoimmune background. Similarly, autoinflammatory syndromes such as familial Mediterranean fever and tumor necrosis factor receptor-associated periodic syndrome are characterized by self-limiting pericardial symptoms. Corticosteroids are generally effective, thus supporting the autoimmune nature of IRAP, but dramatic results are obtained with interleukin-1 blocking agents in corticosteroid-dependent cases, pointing to a pathogenic role for the inflammasome. Based on these observations, we submit that IRAP represents a paradigmatic example of the putative coexistence of autoimmunity and autoinflammation: the main aim of this review is to critically discuss the hypothesis as well as the current understanding of this enigmatic clinical condition.

Caveats and truths in genetic, clinical, autoimmune and autoinflammatory issues in Blau syndrome and early onset sarcoidosis

Blau syndrome (BS) and early onset sarcoidosis (EOS) are, respectively, the familial and sporadic forms of the pediatric granulomatous autoinflammatory disease, which belong to the group of monogenic autoinflammatory syndromes. Both of these conditions are caused by mutations in the NOD2 gene, which encodes the cytosolic NOD2 protein, one of the pivotal molecules in the regulation of innate immunity, primarily expressed in the antigen-presenting cells. Clinical onset of BS and EOS is usually in the first years of life with noncaseating epithelioid granulomas mainly affecting joints, skin, and uveal tract, variably associated with heterogeneous systemic features. The dividing line between autoinflammatory and autoimmune mechanisms is probably not so clear-cut, and the relationship existing between BS or EOS and autoimmune phenomena remains unclear. There is no established therapy for the management of BS and EOS, and the main treatment aim is to prevent ocular manifestations entailing the risk of potential blindness and to avoid joint deformities. Nonsteroidal anti-inflammatory drugs, corticosteroids and immunosuppressive drugs, such as methotrexate or azathioprine, may be helpful; when patients are unresponsive to the combination of corticosteroids and immunosuppressant agents, the tumor necrosis factor-α inhibitor infliximab should be considered. Data on anti-interleukin-1 inhibition with anakinra and canakinumab is still limited and further corroboration is required. The aim of this paper is to describe BS and EOS, focusing on their genetic, clinical, and therapeutic issues, with the ultimate goal of increasing clinicians' awareness of both of these rare but serious disorders.

Untangling the web of systemic autoinflammatory diseases

The innate immune system is involved in the pathophysiology of systemic autoinflammatory diseases (SAIDs), an enlarging group of disorders caused by dysregulated production of proinflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α, in which autoreactive T-lymphocytes and autoantibodies are indeed absent. A widely deranged innate immunity leads to overactivity of proinflammatory cytokines and subsequent multisite inflammatory symptoms depicting various conditions, such as hereditary periodic fevers, granulomatous disorders, and pyogenic diseases, collectively described in this review. Further research should enhance our understanding of the genetics behind SAIDs, unearth triggers of inflammatory attacks, and result in improvement for their diagnosis and treatment.

New age of biological therapies in paediatric rheumatology

Many paediatric rheumatic diseases result from the abnormal activation or control of the immune system. Biologic drugs, which are synthesised within a biological system, have been designed to target specific molecules involved in cytokine signalling or cell-cell interactions. The past 15 years have seen a revolution in the range of effective treatments for rheumatic diseases, particularly juvenile idiopathic arthritis (JIA). As a result, the target of inactive disease and minimal long-term disease-associated damage is increasingly becoming achievable. In this article we review evidence from recent trials of the use of biologic drugs in the treatment of systemic JIA, juvenile dermatomyositis and juvenile systemic lupus erythematosus. We also highlight novel agents currently undergoing investigation which may broaden our therapeutic armamentarium over the coming decade. Key to these developments are well-designed multicentre controlled clinical trials and long-term safety monitoring as part of international drug registries.

Biological treatments in Behçet's disease: beyond anti-TNF therapy

Behçet's disease (BD) is universally recognized as a multisystemic inflammatory disease of unknown etiology with chronic course and unpredictable exacerbations: its clinical spectrum varies from pure vasculitic manifestations with thrombotic complications to protean inflammatory involvement of multiple organs and tissues. Treatment has been revolutionized by the progressed knowledge in the pathogenetic mechanisms of BD, involving dysfunction and oversecretion of multiple proinflammatory molecules, chiefly tumor necrosis factor- (TNF-) α, interleukin- (IL-) 1β, and IL-6. However, although biological treatment with anti-TNF-α agents has been largely demonstrated to be effective in BD, not all patients are definite responders, and this beneficial response might drop off over time. Therefore, additional therapies for a subset of refractory patients with BD are inevitably needed. Different agents targeting various cytokines and their receptors or cell surface molecules have been studied: the IL-1 receptor has been targeted by anakinra, the IL-1 by canakinumab and gevokizumab, the IL-6 receptor by tocilizumab, the IL12/23 receptor by ustekinumab, and the B-lymphocyte antigen CD-20 by rituximab. The aim of this review is to summarize all current experiences and the most recent evidence regarding these novel approaches with biological drugs other than TNF-α blockers in BD, providing a valuable addition to the actually available therapeutic armamentarium.

The labyrinth of autoinflammatory disorders: a snapshot on the activity of a third-level center in Italy

Autoinflammatory disorders (AIDs) are a novel class of diseases elicited by mutations in genes regulating the homeostasis of innate immune complexes, named inflammasomes, which lead to uncontrolled oversecretion of the proinflammatory cytokine interleukin-1β. Protean inflammatory symptoms are variably associated with periodic fever, depicting multiple specific conditions. Childhood is usually the lifetime in which most hereditary AIDs start, though still a relevant number of patients may experience a delayed disease onset and receive a definite diagnosis during adulthood. As a major referral laboratory for patients with recurrent fevers, we have tested samples from 787 patients in the period September 2007-March 2014, with a total of 1,328 AID-related genes evaluated and a gene/patient ratio of 1.69. In this report, we describe our experience in the clinical approach to AIDs, highlight the most striking differences between child and adult-onset AIDs, and shed an eye-opening insight into their diagnostic process.