Clinical and Genetic Spectrum of Nine Cases of NLRP3-Associated Autoinflammatory Disease (NLRP3-AID) and Identification of One Novel NLRP3 Mutation by Genetic Variation Analyses.

Purpose: NLRP3-associated autoinflammatory disease (NLRP3-AID) is characterized by gain-of-function variants in the NLRP3 gene. Since there are little literature focusing on pediatric NLRP3-AID in China, we aimed to elucidate the phenotypic and genotypic profiles of Chinese patients with NLRP3-AID. Methods: Patients with NLRP3-AID at three rheumatology centers in China were genotyped through whole exome sequencing or gene panel sequencing. Sanger sequencing was performed on all patients and their parents. Clinical phenotype, treatment, and prognosis were analyzed. Results: Nine patients with NLRP3-AID were enrolled between December 2014 and October 2022 with an average follow-up period exceeding 30 months. The median age of onset was 12 months, and 66.7% were younger than 3 years old. The diagnosis was significantly delayed and the median delay duration was 115 months. The patients most commonly presented with rash (100%), arthritis/arthralgia (88.9%), lymphadenopathy (88.9%), fever (77.8%), and growth retardation (44.4%). During acute attack, white blood cell, C-reactive protein, and/or erythrocyte sedimentation rate all increased in all cases, and inflammatory markers remained elevated beyond 7 days postfever resolution in 57.1% of patients (4/7). Two cases of chronic infantile neurological cutaneous articular syndrome (CINCA) had clubbed fingers, one with interstitial lung disease, a finding rarely reported. Treatment with glucocorticoids (77.8%) and biologic agents (33.3%) yielded 66% complete remission and 33% partial remission. Genetic analysis identified eight pathogenic NLRP3 missense mutations, including one novel mutation. Conclusions: Our study illuminated the distinct clinical and genetic features of Chinese NLRP3-AID patients, emphasizing the significance of early genetic screening. Despite delayed diagnosis, treatment primarily with glucocorticoids and biologic agents, led to favorable outcomes. Genetic heterogeneity, including a novel mutation, highlighted the complexity of NLRP3-AID in this population.

Isoliquiritigenin inhibits NLRP3 inflammasome activation with CAPS mutations by suppressing caspase-1 activation and mutated NLRP3 aggregation.

The nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain containing 3 (NLRP3) inflammasome contributes to the development of inflammatory diseases. Cryopyrin-associated periodic syndrome (CAPS) is an autoinflammatory disease caused by NLRP3 gene mutations that results in excessive IL-1ß production. We previously identified isoliquiritigenin (ILG), a component of Glycyrrhiza uralensis extracts, as a potent inhibitor of the NLRP3 inflammasome. Here, we aimed to investigate whether ILG inhibits the activation of NLRP3 inflammasome caused by NLRP3 gene mutations. We demonstrated that ILG significantly inhibited NLRP3 inflammasome-mediated lactate dehydrogenase (LDH) release and IL-1ß production in two CAPS model THP-1 cell lines, NLRP3-D303N and NLRP3-L353P, in a dose-dependent manner. Interestingly, the NLRP3 inhibitor MCC950 inhibited LDH release and IL-1ß production in NLRP3-D303N cells, but not in NLRP3-L353P cells. Western blotting and caspase-1 activity assays showed that ILG, as well as caspase inhibitors, including Z-VAD and YVAD, suppressed caspase-1 activation. Notably, ILG prevented cryo-sensitive foci formation of NLRP3 without affecting the levels of intracellular Ca2+. We concluded that ILG effectively prevents the constitutive activation of the inflammasome associated with NLRP3 gene mutations by inhibiting the aggregation of cryo-sensitive mutated NLRP3.

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.

Practical Approach to Diagnosis and Management of IL-1-Mediated Autoinflammatory Diseases (CAPS, TRAPS, MKD, and DIRA).

Systemic autoinflammatory diseases (SAIDs) are a group of rare genetic and nongenetic immune dysregulatory disorders associated with high morbidity and mortality if left untreated. Therefore, early diagnosis and initiation of targeted treatment is vital in SAID patients to control the disease activity and prevent long-term immune-mediated damage. A specific group of genetically defined SAIDs is associated with increased inflammasome-mediated production of active interleukin (IL)-1. Even though progress in immunobiology and genetics has brought forth diagnostic tools and novel treatments that have been described in the literature extensively, many challenges remain in the clinical setting. Some challenges that health care providers may face on a day-to-day basis include the requirement of a multidisciplinary approach due to the complexity of these diseases, limited evidence-based treatment options, and barriers to access available therapies. Primarily, IL-1 inhibitors anakinra, canakinumab, and rilonacept are used to control the inflammation in these patients, with the goal of achieving sustainable remission. Recently published provisional points to consider from the European Alliance of Associations for Rheumatology (EULAR) and American College of Rheumatology (ACR) provide diagnosis, management, and monitoring recommendations for four IL-1-mediated autoinflammatory diseases: cryopyrin-associated periodic syndromes (CAPS), tumour necrosis factor receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD), and deficiency of the IL-1 receptor antagonist (DIRA). The goal of this paper is to aid health care professionals by providing a practical approach to diagnosis and management of these four IL-1 mediated SAIDs on the basis of the recent EULAR/ACR recommendations.

HSP90ß controls NLRP3 autoactivation.

Gain-of-function mutations in NLRP3 are linked to cryopyrin-associated periodic syndromes (CAPS). Although NLRP3 autoinflammasome assembly triggers inflammatory cytokine release, its activation mechanisms are not fully understood. Our study used a functional genetic approach to identify regulators of NLRP3 inflammasome formation. We identified the HSP90ß-SGT1 chaperone complex as crucial for autoinflammasome activation in CAPS. A deficiency in HSP90ß, but not in HSP90α, impaired the formation of ASC specks without affecting the priming and expression of inflammasome components. Conversely, activating NLRP3 with stimuli such as nigericin or alum bypassed the need for SGT1 and HSP90ß, suggesting the existence of alternative inflammasome assembly pathways. The role of HSP90ß was further demonstrated in PBMCs derived from CAPS patients. In these samples, the pathological constitutive secretion of IL-1ß could be suppressed using a pharmacological inhibitor of HSP90ß. This finding underscores the potential of SGT1-HSP90ß modulation as a therapeutic strategy in CAPS while preserving NLRP3's physiological functions.

Adult patient diagnosed with Muckle-Wells syndrome, antiphospholipid syndrome and glomerular haematuria.

Muckle-Wells syndrome (MWS) is a genetic periodic fever syndrome characterised by urticaria, fever and malaise starting in childhood with the development of perceptive hearing loss and risk of amyloidosis later in life.Patient A, in his 60s, was referred to a nephrologist because of glomerular haematuria and elevated erythrocyte sedimentation rate. He appeared to have periodic fevers since childhood, skin changes in cold circumstances and progressive deafness since he was 30 years of age. Genetic analysis revealed a pathogenic variant in the NLRP3 gene compatible with MWS. Treatment with anakinra (interleukin 1 antagonist) improved his symptoms, but only mild episodic arthralgia remained. Glomerular erythrocyturia diminished during treatment, supposing a relation between MWS and haematuria.This case report shows that rare genetic fever syndromes starting from early childhood can still be diagnosed in adult patients, with important therapeutic consequences. Symptoms can be relieved and amyloidosis with potential renal failure may be prevented.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of ZY-IL1 in Three Patients with Cryopyrin-Associated Periodic Syndromes.

We present the first results of the proof-of-concept phase 2a study of oral NLRP3 inflammasome inhibitor in subjects with cryopyrin-associated periodic syndromes (CAPS). Three adult subjects with a confirmed diagnosis of CAPS were enrolled and administered 50 mg of ZYIL1 twice daily for 7 days. A total of 5 treatment-emergent adverse events (TEAEs) were reported in 2 subjects. All 5 TEAEs were mild in severity and considered unrelated to the study drug. At steady state, the average plasma concentration and trough concentration ranged from 2.5 to 4.2 and 1.4 to 2.5 µg/mL, respectively. Inflammatory markers and disease activity (physician and patient global assessment score) decreased notably 12 hours post-last dose.

Discovery of a Novel Missense Variant in NLRP3 Causing Atypical Cryopyrin-Associated Periodic Syndromes With Hearing Loss as the Primary Presentation, Responsive to Anti-Interleukin-1 Therapy.

OBJECTIVE: Cryopyrin-associated periodic syndromes (CAPS), also known as NLRP3-associated autoinflammatory diseases, are a spectrum of rare autoinflammatory diseases caused by gain-of-function variants in the NLRP3 gene, resulting in inflammasome hyperactivation and dysregulated release of interleukin-1ß (IL-1ß). Many patients with CAPS develop progressive sensorineural hearing loss (SNHL) because of cochlear autoinflammation, which may be the sole manifestation in rare cases. This study was undertaken to establish the suspected diagnosis of CAPS in a family presenting with autosomal-dominant progressive/acute SNHL and a novel missense variant in the NLRP3 gene of unknown significance (NM_001079821.3:c.1784G>A p.Ser595Asn). METHODS: We conducted an ex vivo functional assessment of the NLRP3 inflammasome in heterozygous individuals (n = 10) and healthy family members (n = 5). RESULTS: The assay revealed hyperactivation of the inflammasome among heterozygous individuals, supporting the hypothesis that this missense variant is a pathogenic gain-of-function variant. Administration of IL-1 receptor antagonist resulted in a substantial clinical improvement among pediatric patients, who exhibited near resolution of hearing impairment within 1 to 3 months of treatment. CONCLUSION: Our findings highlight the crucial role of early diagnosis and treatment with an anti-IL-1 agent in reversing cochlear damage. Furthermore, our results suggest that high- and ultrahigh-frequency ranges need to be included in the auditory assessment to enable early detection of subclinical SNHL. Finally, incorporating functional inflammasome assessment as part of the clinical evaluation could establish the diagnosis in inconclusive cases.

The discovery of NLRP3 and its function in cryopyrin-associated periodic syndromes and innate immunity.

From studies of individual families to global collaborative efforts, the NLRP3 inflammasome is now recognized to be a key regulator of innate immunity. Activated by a panoply of pathogen-associated and endogenous triggers, NLRP3 serves as an intracellular sensor that drives carefully coordinated assembly of the inflammasome, and downstream inflammation mediated by IL-1 and IL-18. Initially discovered as the cause of the autoinflammatory spectrum of cryopyrin-associated periodic syndrome (CAPS), NLRP3 is now also known to play a role in more common diseases including cardiovascular disease, gout, and liver disease. We have seen cohesion in results from clinical studies in CAPS patients, ex vivo studies of human cells and murine cells, and in vivo murine models leading to our understanding of the downstream pathways, cytokine secretion, and cell death pathways that has solidified the role of autoinflammation in the pathogenesis of human disease. Recent advances in our understanding of the structure of the inflammasome have provided ways for us to visualize normal and mutant protein function and pharmacologic inhibition. The subsequent development of targeted therapies successfully used in the treatment of patients with CAPS completes the bench to bedside translational loop which has defined the study of this unique protein.

The genetic and clinical characteristics and effects of Canakinumab on cryopyrin-associated periodic syndrome: a large pediatric cohort study from China.

Cryopyrin-associated periodic syndrome (CAPS) comprises a group of disorders characterized by recurrent bouts of systemic inflammation related to overactivation of inflammasome. So far, neither large cases of the correlation between genotype and phenotype nor treatment strategies have been clearly stated in China. Here, we studied the clinical and genetic characteristics and their correlation from 30 CAPS patients in China. We identified the pathogenesis for novel mutations by activating NLRP3 inflammasome for peripheral cells with ATP plus LPS, compared characteristics with other case series, and analyzed treatment outcomes of these patients. The patients harbored 19 substitutions in NLRP3, and 8 of them were novel mutations. Among these novel mutations, percentages of severe musculoskeletal, ophthalmologic, and neurological symptoms were higher compared with other case serials. The correlation of phenotypes and their variants seemed different in our cases, such as T350M, S333G/I/R, and F311V (somatic mosaicism). Ten patients received Canakinumab treatment, which proved effective at alleviating musculoskeletal, neurological, auditory, visual manifestations, fever, and rash for 10-20 months follow-up. Patients treated with prednisolone or prednisolone plus thalidomide or methotrexate, tocilizumab, TNF inhibiting agents, and sirolimus achieved only partial remission. Importantly, we firstly identified somatic mosaicism mutation of F311V, which was severe. Our study extended the spectrum of genotype and phenotype and characteristics of their correlations and provided detailed responses to different treatment strategies. These data provide guidance for future diagnosis and management for CAPS.

Case Report: A de novo NLRP3 variant resulting in autoinflammatory disease in a Chinese newborn.

Background: Cryopyrin-associated periodic syndromes (CAPS) have been considered autoinflammatory diseases resulting from NLRP3 gene mutations. In recent years, these conditions have been redefined as NLRP3-associated autoinflammatory diseases (NLRP3-AID). Our previous study highlighted a case of a Chinese individual carrying the de novo NLRP3 mutation. Results: A female child carrying a de novo variant (c.1718T>G, p. L573W) in the NLRP3 gene was presented in this work. The patient manifested various symptoms, including recurrent fever, a rash resembling urticaria, arthritis, physical growth retardation, a notable prominence of the forehead, and a flat nose bridge. Additionally, inflammatory markers, like WBC count, PLT count, CRP, ESR, and IL-6 showed elevated levels. Additionally, we observed interstitial pulmonary disease in the patient, which is not frequently mentioned in previous studies. Notably, the proband did not present with any ocular, auditory, or neurological symptoms. After 12 weeks of subcutaneous canakinumab injection, there was a clear improvement in the patient's clinical manifestations and inflammatory markers. Conclusion: Our study contributes to broadening the clinical spectrum of established pathogenic variants of NLRP3 gene, which are related to NLRP3-AID.

NLRP12-associated autoinflammatory disease: much more than the FCAS phenotype.

OBJECTIVES: NLRP12-associated autoinflammatory disease (NLRP12-AID) is a rarely seen periodic fever syndrome also known as familial cold autoinflammatory syndrome-2 (FCAS2), caused by autosomal dominant inherited mutations in the NLRP12 gene. We aimed to present our clinical experience constituting one of the largest paediatric NLRP12-AID cohort. METHODS: The patients with preliminary diagnosis of systemic autoinflammatory disease (SAID) other than familial Mediterranean fever (FMF) and PFAPA syndrome were evaluated with the next-generation-sequence (NGS) genetic-panel analysis between January-2016 and January-2022. Among children carrying NLRP12-variant, patients with recurrent episodes of autoinflammatory disease manifestations were diagnosed with NLRP12-AID. Demographic, clinical and laboratory data, treatments and outcomes of patients were presented. RESULTS: Seventeen patients were diagnosed with NLRP12-AID. The mean age at diagnosis was 114.7±69.5 months. The most frequently seen clinical manifestations were respectively; fever (100%), arthritis/arthralgia (58.8%), rash (52.9%), abdominal pain (52.9%), diarrhoea (41.2%), myalgia/fatigue (53.2%) and, conjunctivitis (11.7%). Clinical manifestations were triggered by cold exposure in three patients (17.6%). Seven patients had pathogenic, one had likely pathogenic, seven had VUS, and two had novel heterozygous variants. The most common defined variant in the NLRP12 gene was R352C. Complete response was achieved in 5 patients and partial response was in 6 with colchicine treatment. Attacks were prevented with anti-IL-1 treatments in 6 patients unresponsive to colchicine. CONCLUSIONS: In conclusion, the disease can cause effects on various tissues, especially the musculoskeletal and gastrointestinal systems, apart from FCAS symptoms. We think that a patient who can be defined as syndrome of undifferentiated recurrent fever should also be evaluated genetically in terms of NLRP12 previously.

Ocular involvement in adult and paediatric patients with monogenic autoinflammatory diseases: a Spanish multicentre retrospective study.

OBJECTIVES: Ophthalmologic involvement in monogenic autoinflammatory diseases has been explored mainly in paediatric patients. The aim of this study is to characterise ophthalmologic manifestations, therapeutic management and visual outcomes in a Spanish (UVESAI) cohort of adult/paediatric patients with monogenic autoinflammatory diseases. METHODS: Multicentre and retrospective study of patients with monogenic autoinflammatory diseases and ocular involvement. Eye manifestations, structural complications, treatments used and visual outcomes were analysed, and compared with previous studies. RESULTS: Forty-six patients (44/2 adults/children; 21/25 adult/paediatric-onset) with monogenic autoinflammatory diseases [cryopyrin associated periodic syndromes (n=13/28.3%), mainly Muckle-Wells syndrome (MWS) (n=11/24%); familial Mediterranean fever (FMF) (n=12/26%); TNF receptor-associated periodic syndrome (TRAPS); (n=9/20%); Blau syndrome (n=8/17%); hyperimmunoglobulin D syndrome (HIDS) (n=2/4.3%), deficiency of adenosine deaminase-2 and NLRC4-Autoinflammatory disease] (one each) were included. Conjunctivitis (n=26/56.5%) and uveitis (n=23/50%) were the most frequent ocular manifestations. Twelve (26.1%) patients developed structural complications, being cataracts (n=11/24%) and posterior synechiae (n=10/22%) the most frequent. Conjunctivitis predominated in TRAPS, FMF, MWS and HIDS (mainly in adults), and uveitis, in Blau syndrome. Seven (8%) eyes (all with uveitis) presented with impaired visual acuity. Local and systemic treatment led to good visual outcomes in most patients. Compared with previous studies mainly including paediatric patients, less severe ocular involvement was observed in our adult/paediatric cohort. CONCLUSIONS: Conjunctivitis was the most common ocular manifestation in our TRAPS, FMF, MWS and HIDS patients, and uveitis predominated in Blau syndrome. Severe eye complications and poor visual prognosis were associated with uveitis. Adults with monogenic autoinflammatory diseases seem to exhibit a less severe ophthalmologic presentation than paediatric patients.

Subdural hemorrhage, macrocephaly, rash, and developmental delay in an infant: A pathogenic variant in NLRP3 causes CINCA/NOMID.

Subdural hemorrhages (SDHs) in children are most often observed in abusive head trauma (AHT), a distinct form of traumatic brain injury, but they may occur in other conditions as well, typically with clear signs and symptoms of an alternative diagnosis. We present a case of an infant whose SDH initially raised the question of AHT, but multidisciplinary evaluation identified multiple abnormalities, including rash, macrocephaly, growth failure, and elevated inflammatory markers, which were all atypical for trauma. These, along with significant cerebral atrophy, ventriculomegaly, and an absence of other injuries, raised concerns for a genetic disorder, prompting genetic consultation. Clinical trio exome sequencing identified a de novo likely pathogenic variant in NLRP3, which is associated with chronic infantile neurological, cutaneous, and articular (CINCA) syndrome, also known as neonatal-onset multisystem inflammatory disease (NOMID). He was successfully treated with interleukin-1 blockade, highlighting the importance of prompt treatment in CINCA/NOMID patients. This case also illustrates how atraumatic cases of SDH can be readily distinguished from AHT with multidisciplinary collaboration and careful consideration of the clinical history and exam findings.

A Knock-In Mouse Model of Cryopyrin-Associated Periodic Syndromes.

Autoinflammatory diseases are a group of distinct disorders characterized by recurrent fever and inflammatory manifestations predominantly mediated by cytokines of the innate immune system, particularly IL-1ß, without involvement of autoantibodies or autoreactive T lymphocytes. Cryopyrin-associated periodic syndromes (CAPS), due to NLRP3 gene mutations, represent the prototype of these diseases. Owing to their genetic nature, most of these disorders have an early onset, ranging from the first hours to the first decade of life. Due to the rarity of CAPS patients and to the limitations of working with pediatric samples, the development of animal models of this disease is of great help for studying both pathophysiology and therapeutic strategies. In this chapter, we review the generation and characterization of a knock-in mouse bearing the NLRP3 gene with the N475K mutation, associated with CINCA, the most severe form of human CAPS.

Socio-professional impact and quality of life of cryopyrin-associated periodic syndromes in 54 patients in adulthood.

OBJECTIVES: Cryopyrin-associated periodic syndromes (CAPS) belongs to the group of hereditary recurrent fever disorders characterised by interleukin1ß-mediated systemic inflammation. Specific treatment by IL-1 targeting drugs has significantly modified the disease evolution. We aimed to evaluate the socio-professional impact of CAPS in the long term and the influence of genetic variants in the phenotype. METHODS: We made a multicentre, observational and descriptive study and collected retrospective data from childhood to adulthood, and until the last year of follow-up. We assessed the quality of life (QoL) of the patients by phone interviews. We also used the SF36 questionnaire including 8 domains: physical function, physical role, body pain, general health, vitality, social function, emotional role and mental health. A high score means a better QoL. RESULTS: Fifty-four patients were evaluated (14 familial cold autoinflammatory syndrome, 27 Muckle-Wells syndrome, 7 chronic infantileneurological cutaneous and articular syndrome. The study showed improvement in symptoms in adulthood and good QoL in all domains apart from school (87%) and work (61%) absenteeism. The MWS group is intermediate in terms of symptoms but seems to describe a better QoL compared to the other groups. The genetic variant alone does not determine the expression of the disease. CONCLUSIONS: Our study shows that CAPS patients have an improvement of symptoms in adulthood and a satisfactory QoL for most of them. Anti-IL1 treatment is the main factor linked to this improvement and therefore early initiation should be encouraged.

Similarities and differences in autoinflammatory diseases with urticarial rash, cryopyrin-associated periodic syndrome and Schnitzler syndrome.

Cryopyrin-associated periodic syndromes (CAPS) and Schnitzler syndrome (SchS) are autoinflammatory diseases that present with urticaria-like rashes. CAPS is characterized by periodic or persistent systemic inflammation caused by the dysfunction of the NLRP3 gene. With the advent of IL-1-targeted therapies, the prognosis of CAPS has improved remarkably. SchS is considered an acquired form of autoinflammatory syndrome. Patients with SchS are adults of relatively older age. The pathogenesis of SchS remains unknown and is not associated with the NLRP3 gene. Previously, the p.L265P mutation in the MYD88 gene, which is frequently detected in Waldenström macroglobulinemia (WM) with IgM gammopathy, was identified in several cases of SchS. However, because persistent fever and fatigue are symptoms of WM that require therapeutic intervention, it is a challenge to determine whether these patients truly had SchS or whether advanced WM was misidentified as SchS. There are no established treatments for SchS. The treatment algorithm proposed with the diagnostic criteria is to use colchicine as first-line treatment, and systemic administration of steroids is not recommended due to concerns about side effects. In difficult-to-treat cases, treatment targeting IL-1 is recommended. If targeted IL-1 treatment does not improve symptoms, the diagnosis should be reconsidered. We hope that the efficacy of IL-1 therapy in clinical practice will serve as a stepping stone to elucidate the pathogenesis of SchS, focusing on its similarities and differences from CAPS.

Presentation of cryopyrin-associated periodic fever syndrome as chronic, afebrile urticaria in a 12-month-old female.

A healthy 12-month-old female presented with relapsing and remitting urticaria since birth that was resistant to treatment with antihistamines. A thorough history revealed extensive rheumatic disease on the father's side of the family, and subsequent genetic testing was positive for a missense variant of NLRP3, indicating cryopyrin-associated periodic fever syndrome (CAPS). CAPS encompasses a spectrum of diseases, all related to a defect in the same gene; manifestations vary in severity and presentation, but most are associated with recurrent rash and fever. Because the patient's only presenting symptom was rash, this case highlights the importance of having a high index of suspicion for cryopyrin-associated periodic fever syndrome in infants with persistent, early urticaria.

Diagnostic and therapeutic algorithms for monogenic autoinflammatory diseases presenting with recurrent fevers among adults.

Autoinflammatory diseases (AIDs) are defined as disorders of innate immunity. They were initially defined in contrast to autoimmune diseases because of the lack of involvement of the adaptive immune system and circulating autoantibodies. The four monogenic AIDs first described are called the 'historical' AIDs and include FMF (associated with MEFV mutations), cryopyrinopathies (associated with NLRP3 mutations), TNF receptor-associated periodic syndrome (associated with TNFRSF1A mutations) and mevalonate kinase deficiency (MKD; associated with MVK mutations). In the last 10 years, >50 new monogenic AIDs have been discovered due to genetic advances. The most important discovery for adult patients is VEXAS syndrome associated with somatic UBA1 mutations leading to an AID affecting mostly elderly men. Diagnosis of monogenic AIDs is based on personal and family history and detailed analysis of symptoms associated with febrile attacks in the context of elevated peripheral inflammatory markers. This review proposes a practical approach for the diagnosis of the main monogenic AIDs among adult patients.

NLRP3 inflammasome and NLRP3-related autoinflammatory diseases: From cryopyrin function to targeted therapies.

The NLRP3 inflammasome is one of the NOD-like receptor family members with the most functional characterization and acts as a key player in innate immune system, participating in several physiological processes including, among others, the modulation of the immune system response and the coordination of host defences. Activation of the inflammasome is a crucial signaling mechanism that promotes both an acute and a chronic inflammatory response, which can accelerate the production of pro-inflammatory cytokines, mainly Interleukin (IL)-1ß and IL-18, leading to an exacerbated inflammatory network. Cryopyrin associated periodic syndrome (CAPS) is a rare inherited autoinflammatory disorder, clinically characterized by cutaneous and systemic, musculoskeletal, and central nervous system inflammation. Gain-of-function mutations in NLRP3 gene are causative of signs and inflammatory symptoms in CAPS patients, in which an abnormal activation of the NLRP3 inflammasome, resulting in an inappropriate release of IL-1ß and gasdermin-D-dependent pyroptosis, has been demonstrated both in in vitro and in ex vivo studies. During recent years, two new hereditary NLRP3-related disorders have been described, deafness autosomal dominant 34 (DFN34) and keratitis fugax hereditaria (KFH), with an exclusive cochlear- and anterior eye- restricted autoinflammation, respectively, and caused by mutations in NLRP3 gene, thus expanding the clinical and genetic spectrum of NLRP3-associated autoinflammatory diseases. Several crucial mechanisms involved in the control of activation and regulation of the NLRP3 inflammasome have been identified and researchers took advantage of this to develop novel target therapies with a significant improvement of clinical signs and symptoms of NLRP3-associated diseases. This review provides a broad overview of NLRP3 inflammasome biology with particular emphasis on CAPS, whose clinical, genetic, and therapeutic aspects will be explored in depth. The latest evidence on two "new" diseases, DFN34 and KFH, caused by mutations in NLRP3 is also described.