Phenotypic and genotypic characteristics of cryopyrin-associated periodic syndrome: a series of 136 patients from the Eurofever Registry

Optic disc changes in Chinese patients with NLRP3-associated autoinflammatory disease

OBJECTIVE

To investigate the optic disc changes (ODC) in Chinese patients with NLRP3-associated autoinflammatory disease (NLRP3-AID).

METHODS

Patients who were diagnosed with NLRP3-AID at the Department of Rheumatology, Peking Union Medical College Hospital between April 2015 and December 2022 were retrospectively reviewed and analyzed.

RESULTS

A total of 20 patients were enrolled in this retrospective study. All 20 patients had a moderate MWS NLRP3-AID phenotype. Thirteen patients (65%) had ocular involvements. The interval between symptoms onset and diagnosis was significantly longer in patients with ocular involvement than in patients without (p = 0.044). The incidence of hearing loss was significantly higher in patients with ocular involvement (p = 0.017), while the incidence of abdominal pain was significantly lower when compared to patients without ocular involvement (p = 0.007). Optic disc swelling (ODS) (50%) was the most common ODC. All of the four T348M mutation carriers within our cohort exhibited ODS with visual-field defects. There was a significant difference between patients with/without ODS regarding the number of patients carrying T348M mutation (p = 0.014). The occurrence of hearing loss and CNS involvement was significantly higher in the group with ODS compared to the group without (p = 0.0014, p = 0.0198). Of the eight patients who underwent lumbar puncture, five presented with intracranial hypertension (IH). ODS was observed in all patients with IH. The serum inflammatory markers were significantly higher in patients with ODS than in those without. Two patients receiving regular subcutaneous IL-1 inhibitor treatment showed improvements in ODC.

CONCLUSIONS

ODC is common among Chinese patients with NLRP3-AID, with ODS being the most common manifestation. Hearing loss and CNS involvement often accompany the occurrence of ODS. The serum inflammatory markers are associated with ODS. The T348M mutation is more likely to lead to ODC with visual-field defects.

4-octyl itaconate reduces human NLRP3 inflammasome constitutive activation with the cryopyrin-associated periodic syndrome p.R262W, p.D305N and p.T350M variants

Cryopyrin-associated periodic syndrome (CAPS) is a condition characterized by dominant genetic variants in the NLRP3 gene, which lead to the formation of constitutively active inflammasomes. These inflammasomes play a crucial role in CAPS patients' inflammatory episodes, these being primarily driven by the production of interleukin (IL)-1b. Although treatment with IL-1 blockers is effective for CAPS, some patients develop refractory responses and adverse reactions to these therapies. Consequently, there is a need for novel treatments for CAPS patients. Promising candidates are the derivatives of itaconate, which have been shown to impair NLRP3 inflammasome activation and IL-1β release in blood mononuclear cells from CAPS patients. In this study, we provide insight into the inhibitory mechanisms by which the itaconate derivative 4-octyl itaconate (4-OI) acts on NLRP3 that has different gain-of-function mutations (p.R262W, p.D305N and p.T350M) associated with CAPS. Notably, 4-OI effectively blocks the basal auto-activation of the inflammasome formed by NLRP3 p.R262W, p.D305N and p.T350M variants, which in turn reduces caspase-1 activation, gasdermin D processing, and IL-18 release. Furthermore, after lipopolysaccharide priming of macrophages, 4-OI also decreases IL-1β gene expression and release. Overall, 4-OI impairs CAPS-associated inflammasome function at multiple levels, meaning that therapeutic agents based on itaconate could be a promising therapeutic approach to managing inflammatory episodes in CAPS patients carrying p.R262W, p.D305N or p.T350M variants.

Supersulfides: A Promising Therapeutic Approach for Autoinflammatory Diseases

Supersulfides are molecular species characterized by catenated sulfur moieties, including low-molecular-weight and protein-bound supersulfides. Emerging evidence suggests that these molecules, abundantly present in diverse organisms, play essential roles far beyond their chemical properties, such as functions in energy metabolism, protein stabilization, and antiviral defense. Recent studies highlight their regulatory effects on pattern-recognition receptors (PRRs) and associated signaling pathways-such as nucleotide oligomerization domain-like receptor signaling, toll-like receptor signaling, and type I interferon receptor signaling-critical for innate immunity and inflammatory responses. Dysregulation of these pathways is implicated in a heterogeneous group of autoinflammatory diseases, including inflammasomopathies, relopathies, and type I interferonopathies, respectively. Notably, both endogenous and synthetic supersulfide donors have recently shown promising inhibitory effects on PRR signaling, offering their potential as targeted therapies for managing autoinflammatory conditions. This review summarizes the fundamental biology of supersulfides and typical autoinflammatory diseases, focusing on their roles in innate immune and inflammatory responses, while exploring their therapeutic potential in these diseases.

Otorhinolaryngological manifestations of autoinflammatory diseases. Systematic review

OBJECTIVES

To detail the main otorhinolaryngological manifestations of autoinflammatory diseases, aiming to contribute to early diagnosis and treatment.

DATA SOURCES

Searches were conducted in PubMed, LILACS, Cochrane Library.

REVIEW METHODS

A systematic review of the medical literature on autoinflammatory diseases was conducted to identify characteristic head and neck manifestations, using PRISMA criteria. Observational studies or systematic reviews with a minimum of 10 cases per disease were included. Qualitative synthesis and a risk assessment were carried out.

RESULTS

Our review included 29 articles that met the inclusion criteria, with 10 to 486 patients per study. Autoinflammatory diseases with characteristic head and neck manifestations included VEXAS syndrome (auricular, nasal, or laryngotracheal chondritis), NPRL3-AID (hearing loss), NPRL12-AID (cervical lymphadenopathies, hearing loss and oral ulcers), HIDSs syndrome (painful cervical nodes and oral ulcers), haploinsufficiency A20 (oral ulcers), TRAPS (pharyngitis, aphthous stomatitis, periorbital edema, and cervical lymphadenopathies), Behcet's disease (oral and pharyngeal ulcers), PFAPA syndrome (recurrent tonsillitis, oral ulcers, and painful cervical adenopathies), Kawasaki disease (cervical nodes, pharyngitis and changes in oral mucosa) and undefined periodic fever (pharyngitis, oral ulcers, and painful cervical nodes).

CONCLUSION

Given their complex diagnosis and unique head and neck manifestations, otolaryngologists must be well-versed in these diseases for early detection and treatment. ENT specialists should consider the possibility of an autoinflammatory disease when encountering symptoms such as auricular, nasal, or laryngeal chondritis, recurrent oral ulcers, painful inflammatory lymphadenopathies, periorbital edema, recurrent pharyngitis, or hearing loss within the context of compatible systemic conditions.

Nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing protein 3 inflammasome: From action mechanism to therapeutic target in clinical trials

The nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome is a critical modulator in inflammatory disease. Activation and mutation of NLRP3 can cause severe inflammation in diseases such as chronic infantile neurologic cutaneous and articular syndrome, Muckle-Wells syndrome, and familial cold autoinflammatory syndrome 1. To date, a great effort has been made to decode the underlying mechanisms of NLRP3 activation. The priming and activation of NLRP3 drive the maturation and release of active interleukin (IL)-18 and IL-1β to cause inflammation and pyroptosis, which can significantly trigger many diseases including inflammatory diseases, immune disorders, metabolic diseases, and neurodegenerative diseases. The investigation of NLRP3 as a therapeutic target for disease treatment is a hot topic in both preclinical studies and clinical trials. Developing potent NLRP3 inhibitors and downstream IL-1 inhibitors attracts wide-spectrum attention in both research and pharmaceutical fields. In this minireview, we first updated the molecular mechanisms involved in NLRP3 inflammasome activation and the associated downstream signaling pathways. We then reviewed the molecular and cellular pathways of NLRP3 in many diseases, including obesity, diabetes, and other metabolic diseases. In addition, we briefly reviewed the roles of NLRP3 in cancer growth and relative immune checkpoint therapy. Finally, clinical trials with treatments targeting NLRP3 and its downstream signaling pathways were summarized.

Recurrent Urticaria: A Rare Cryopyrin-Associated Periodic Syndrome - Muckle-Wells Syndrome

Introduction

Muckle-Wells syndrome (MWS) is a rare cryopyrin-associated periodic syndrome (CAPS), an autoinflammatory disorder due to a loss of function mutation in the NACHT domain of the NLRP3 gene. The loss of cryopyrin activity brought on by this deficiency eventually causes dysregulated inflammation and increased release of the proinflammatory cytokine interleukin (IL)-1 beta. It has an autosomal dominant inheritance.

Case Presentation

We present here an 8-year-old girl with recurrent fever, recurrent urticarial rash, sensorineural hearing loss, raised inflammatory markers and serum amyloid levels, which did not respond to the anti-histaminic drugs, was wrongly diagnosed as tuberculosis, which on further genetic evaluation was diagnosed as MWS.

Conclusion

Despite being uncommon, treating clinicians should take MWS into consideration given the specific clinical presentation. With the availability of appropriate medications, future complications can be prevented, and the prognosis is better.

Breaking the barriers: Overcoming cancer resistance by targeting the NLRP3 inflammasome

Inflammation has a pivotal role in the initiation and progression of various cancers, contributing to crucial processes such as metastasis, angiogenesis, cell proliferation and invasion. Moreover, the release of cytokines mediated by inflammation within the tumour microenvironment (TME) has a crucial role in orchestrating these events. The activation of inflammatory caspases, facilitated by the recruitment of caspase-1, is initiated by the activation of pattern recognition receptors on the immune cell membrane. This activation results in the production of proinflammatory cytokines, including IL-1β and IL-18, and participates in diverse biological processes with significant implications. The NOD-Like Receptor Protein 3 (NLRP3) inflammasome holds a central role in innate immunity and regulates inflammation through releasing IL-1β and IL-18. Moreover, it interacts with various cellular compartments. Recently, the mechanisms underlying NLRP3 inflammasome activation have garnered considerable attention. Disruption in NLRP3 inflammasome activation has been associated with a spectrum of inflammatory diseases, encompassing diabetes, enteritis, neurodegenerative diseases, obesity and tumours. The NLRP3 impact on tumorigenesis varies across different cancer types, with contrasting roles observed. For example, colorectal cancer associated with colitis can be suppressed by NLRP3, whereas gastric and skin cancers may be promoted by its activity. This review provides comprehensive insights into the structure, biological characteristics and mechanisms of the NLRP3 inflammasome, with a specific focus on the relationship between NLRP3 and tumour-related immune responses, and TME. Furthermore, the review explores potential strategies for targeting cancers via NLRP3 inflammasome modulation. This encompasses innovative approaches, including NLRP3-based nanoparticles, gene-targeted therapy and immune checkpoint inhibitors.

Genetic and epigenetic dysregulation of innate immune mechanisms in autoinflammatory diseases

Dysregulation and hyperactivation of innate immune responses can lead to the onset of systemic autoinflammatory diseases. Monogenic autoinflammatory diseases are caused by inborn genetic errors and based on molecular mechanisms at play, can be divided into inflammasomopathies, interferonopathies, relopathies, protein misfolding, and endogenous antagonist deficiencies. On the other hand, more common autoinflammatory diseases are multifactorial, with both genetic and non-genetic factors playing an important role. During the last decade, long-term memory characteristics of innate immune responses have been described (also called trained immunity) that in physiological conditions provide enhanced host protection from pathogenic re-infection. However, if dysregulated, induction of trained immunity can become maladaptive, perpetuating chronic inflammatory activation. Here, we describe the mechanisms of genetic and epigenetic dysregulation of the innate immune system and maladaptive trained immunity that leads to the onset and perpetuation of the most common and recently described systemic autoinflammatory diseases.

Coexistence of systemic sclerosis and cryopyrin-associated periodic syndrome

Systemic sclerosis (SSc) and cryopyrin-associated periodic syndrome (CAPS) are distinct clinical entities belonging to the autoimmune and autoinflammatory diseases, respectively. The coexistence of the two entities has rarely been reported and is poorly characterized. Here, we described a case of a 38-year-old Japanese woman diagnosed with anti-centromere antibody-positive SSc and CAPS carrying the pathogenic mutation in the NLRP3 gene, with a detailed autoantibody profile by a high-throughput comprehensive protein array covering approximately 90% of the human transcriptome. The clinical manifestations of the patient were typical of both SSc and CAPS. Comprehensive autoantibody profiling identified 65 autoantibodies in the patient's serum and 78 autoantibodies in the serum of her daughter with CAPS, who carried the same NLRP3 mutation as the patient. SSc-associated autoantibodies (anti-DBT, anti- CENP-B, and anti-CENP-A) and anti-CD320 antibody were detected at high levels only in the patient's serum, while autoantibodies to the following four proteins were detected in the sera of both the patient and her daughter: TRIM21, LIMS1, CLIP4, and KAT2A. The TRRUST enrichment analysis identified NF-κB1 and RelA as overlapping key transcription factors that regulate the genes encoding proteins to which autoantibodies were detected in the patient and her daughter, therefore the autoantibody profile of the patient cannot be solely attributed to SSc, but may also be influenced by CAPS. Although autoimmune and autoinflammatory diseases are considered to be at opposite ends of the immunological spectrum, detailed autoantibody profiling may reveal a unique immunological landscape in an overlapping case of the two entities.

Implication of the LRR Domain in the Regulation and Activation of the NLRP3 Inflammasome

The NLRP3 inflammasome is a critical component of the innate immune response. NLRP3 activation is a tightly controlled process involving an initial priming to express NLRP3, pro-IL-1 β, and pro-IL-18, followed by an activation signal. The precise mechanism of activation is not fully understood due to the diverse range of activators, yet it effectively orchestrates the activation of caspase-1, which subsequently triggers the release of proinflammatory cytokines IL-1β and IL-18. NLRP3 dysregulation can lead to a variety of inflammatory diseases, highlighting its significant role in immune response and disease pathogenesis. NLRP3 is divided into three domains: the PYD, the NACHT, and the LRR domains. This review focuses on the LRR domain of NLRP3, detailing its structural characteristics, its function in pathogen sensing, its role in the degradation process, and its involvement in inflammasome auto-inhibition and activation. Additionally, we discuss the impact of mutations within the LRR domain found in atypical Cryopyrin-Associated Periodic Syndromes (CAPS), highlighting the clinical relevance of this domain.

Long-term renal outcome of Cryopyrin-associated periodic syndrome (CAPS) under anti-Interleukin-1 therapy

Cryopyrin-associated periodic syndromes (CAPS) are orphan hereditary auto-inflammatory diseases with various phenotypes, including chronic kidney disease (CKD). Current therapies inhibit interleukin-1 (IL-1) to achieve clinical and serological remission; however, the effect on kidney involvement remains unclear. The objective of this study was to investigate the long-term efficacy of anti-IL-1 treatment with special emphasis on renal outcome. We retrospectively analysed clinical, genetic and laboratory data of patients with CAPS under anti-IL-1 therapy from a single-centre university outpatient clinic. Patients with CAPS (n = 28) were followed for a median of 11 (IQR 8.5-13) years. Four patients at various ages (19%), bearing the most common CAPS mutation R260W, had significant CKD at presentation. All affected patients were related; however, other family members with the same genetic variant did not develop CKD. While anti-IL-1 therapy was effective in lowering symptom burden and inflammatory parameters in all CAPS patients, two of the four individuals with significant CKD had persistent proteinuria and worsening kidney function. None of the patients without renal affection at therapy initiation developed relevant CKD in the follow-up period. We showed that in patients with CAPS: (1) CKD is a common complication; (2) renal involvement shows familial predisposition beyond the mutational status and is independent of age; (3) anti-IL-1 therapy results in sustained improvement of inflammatory parameters and symptom load and (4) may prevent development of CAPS-associated CKD but not affect kidney involvement when already present. Overall, early therapy initiation might sufficiently prevent renal disease manifestation and attenuate progression.

A case of cryopyrin-associated periodic syndrome due to somatic mosaic mutation complicated with recurrent circinate erythematous psoriasis

Cryopyrin-associated periotic syndrome (CAPS) is a rare autoinflammatory disease caused by genetic variants in innate immunity genes. Autoinflammatory diseases, including CAPS, mediate proinflammatory cytokines such as interleukin (IL)-1 and IL-18 and result in severe systemic inflammation. A gain-of-function mutation in the NLR family pyrin domain-containing 3 (NLRP3) gene, which encodes the protein cryopyrin, was identified to be responsible for CAPS in 2001, and since then several additional pathogenic mutations have been found. Moreover, other phenotypes have been identified based on severity and symptomatology, including familial cold autoinflammatory syndrome, Muckle-Wells syndrome, and neonatal-onset multisystem inflammatory disease/chronic neurologic cutaneous articular syndrome. Prompt diagnosis of CAPS remains challenging, however, due to unspecific, extensive clinical signs, and delayed diagnosis and treatment targeting IL-1 lead to multiorgan damage. Another factor complicating diagnosis is the existence of somatic mosaic mutations in the NLRP3 gene in some cases, resulting in symptoms and clinical courses that are atypical. The frequency of somatic mosaic mutations in CAPS was estimated to be 19% in a systematic review. Psoriasis is a chronic inflammatory skin disease that affects ∼3% of the global population. Although no reports have shown complication between CAPS and psoriasis, these diseases have several similarities and potential relationships, for instance activation of T helper 17 cells in the dermis and increased NLRP3 gene expression in psoriatic skin compared with normal skin. Here, we report a case of CAPS due to a somatic mosaic mutation with recurrent circinate erythematous psoriasis.

[Cryopyrin-associated periodic fever syndrome (CAPS) presenting as early-onset dementia, lacking typical recurrent fever or skin rash: a case report]

A 54-year-old man with a university degree was admitted to our hospital because of a two-year history of progressive dementia. He had familial sensorineural hearing loss and had been treated for epilepsy since his 30s. On admission, he showed severe dementia and parkinsonism without fever or skin rash. Systemic inflammation was evident, and the CSF cell count and IL-6 level were elevated to 53/μl and 307 ‍pg/ml, respectively. Brain MRI demonstrated diffuse brain atrophy. More detailed anamnesis revealed a history of rheumatoid arthritis in childhood and aseptic meningitis in his 20s. Genetic examination for autoinflammatory diseases demonstrated compound heterozygotic mutations in the NLRP3 gene, causing cryopyrin-associated periodic fever syndrome (CAPS). This case was atypical CAPS presenting as early-onset progressive dementia, without recurrent fever or urticaria-like eruption which are usually seen in this disease.

Clinical Characteristics of Cryopyrin-Associated Periodic Syndrome and Long-Term Real-World Efficacy and Tolerability of Canakinumab in Japan: Results of a Nationwide Survey

OBJECTIVE

We assess the clinical characteristics of patients with cryopyrin-associated periodic syndrome (CAPS) in Japan and evaluate the real-world efficacy and safety of interleukin-1 (IL-1) inhibitors, primarily canakinumab.

METHODS

Clinical information was collected retrospectively, and serum concentrations of canakinumab and cytokines were analyzed.

RESULTS

A total of 101 patients were included, with 86 and 15 carrying heterozygous germline and somatic mosaic mutations, respectively. We identified 39 mutation types, and the common CAPS-associated symptoms corresponded with those in previous reports. Six patients (5.9% of all patients) died, with four of the deaths caused by CAPS-associated symptoms. Notably, 73.7% of patients (100%, 79.6%, and 44.4% of familial cold autoinflammatory syndrome, Muckle-Wells syndrome, and chronic infantile neurological cutaneous articular syndrome/neonatal onset multisystem inflammatory disease, respectively) achieved complete remission with canakinumab, and early therapeutic intervention was associated with better auditory outcomes. In some patients, canakinumab treatment stabilized the progression of epiphysial overgrowth and improved height gain, visual acuity, and renal function. However, 23.7% of patients did not achieve inflammatory remission with crucial deterioration of organ damage, with two dying while receiving high-dose canakinumab treatment. Serological analysis of canakinumab and cytokine concentrations revealed that the poor response was not related to canakinumab shortage. Four inflammatory nonremitters developed inflammatory bowel disease (IBD)-unclassified during canakinumab treatment. Dual biologic therapy with canakinumab and anti-tumor necrosis factor-α agents was effective for IBD- and CAPS-associated symptoms not resolved by canakinumab monotherapy.

CONCLUSION

This study provides one of the largest epidemiologic data sets for CAPS. Although early initiation of anti-IL-1 treatment with canakinumab is beneficial for improving disease prognosis, some patients do not achieve remission despite a high serum concentration of canakinumab. Moreover, IBD may develop in CAPS after canakinumab treatment.

[The most frequent febrile syndromes and autoinflammatory diseases in adulthood]

Autoinflammatory diseases are characterized by inflammatory manifestations in various organ systems, whereby recurrent febrile episodes, musculoskeletal complaints, gastrointestinal and cutaneous symptoms frequently occur accompanied by serological signs of inflammation. Autoinflammatory diseases include rare monogenic entities and multifactorial or polygenic diseases, which can manifest as a variety of symptoms in the course of time. Examples of monogenic autoinflammatory diseases are familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) and the recently described VEXAS (vacuoles, E1 enzyme, X‑linked, autoinflammatory and somatic) syndrome. For non-monogenically determined autoinflammatory diseases, the most important representatives in adulthood are adult-onset Still's disease (AOSD) and the Schnitzler syndrome, in which a polygenic susceptibility and epigenetic factors are more likely to play a role.

Clinical Reasoning: A 24-Year-Old Man With Gait Impairment, Hearing Loss, and Recurrent Fever

We present a case study of a 24-year-old man who reported mild balance and walking difficulties for 2 years. He had a history of recurrent fever, skin lesions, headache, and elbow pain, but most of these events resolved spontaneously. There was no significant family history. On examination, we observed frontal bossing, sensorineural hearing loss, and gait ataxia. This case underscores the significance of identifying clinical indicators in patients with neurologic symptoms, particularly recurrent fever, to establish a precise and thorough differential diagnosis.

Phenotypic and genotypic characterization of Chinese adult patients with NLRP3-associated autoinflammatory disease with hearing loss

OBJECTIVES

Nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3-associated autoinflammatory disease (NLRP3-AID) is a rare autosomal dominant systemic autoinflammatory disease. We aimed to summarize the phenotypic and genotypic features of Chinese adult NLRP3-AID patients with hearing loss.

METHODS

A retrospective cohort study of twenty-one adult patients with NLRP3-AID was conducted in Peking Union Medical College Hospital between July 2015 and March 2023. All patients underwent whole exome sequencing and otorhinolaryngologic assessments. Clinical features and therapeutic data were collected and analysed.

RESULTS

We found that 13/21 (61.90%) of patients had hearing loss with high-frequency impairment in the majority, and most patients presented with vestibular dysfunction as a new finding. The NLRP3-AID patients with early-onset, cold or stress triggered episodes, red eyes, fatigue, hypopsia and mutations located in the NACHT domain of the NLRP3 protein were more likely to suffer from hearing loss, especially sensorineural hearing loss, perhaps as a result of pathogenic variants of high penetrance. By a series of audiological evaluations, TNF-α inhibitors were confirmed to improve or reverse hearing loss.

CONCLUSIONS

We reported the first cohort of Chinese adult NLRP3-AID patients with hearing loss and characterized vestibular dysfunction, highlighted the necessity for attention to high-frequency hearing and provided potential alternative treatment.

Case Report: Efficacy, safety, and favorable long-term outcome of early treatment with IL-1 inhibitors in a patient with chronic infantile neurological cutaneous articular (CINCA) syndrome caused by NLRP3 mosaicism

Chronic infantile neurological cutaneous articular (CINCA) syndrome is an autoinflammatory disease encompassed in the group of cryopyrin-associated periodic syndromes (CAPS). Patients suffering from CINCA have an elevated risk of developing chronic sequelae, including deforming arthropathy, chronic meningitis, neurodevelopmental delay, and neurosensorial hearing loss. The diagnosis of CINCA presents several difficulties, as the clinical phenotype could be difficult to recognize, and almost half of the patients have negative genetic testing. In this paper, we describe the case of a patient presenting with the typical phenotype of neonatal-onset CINCA who resulted negative for NLRP3 mutations. Based on the clinical judgment, the patient underwent treatment with anti-interleukin-1 (IL-1) agents (anakinra and, later, canakinumab) resulting in a complete clinical and laboratory response that allowed confirmation of the diagnosis. Additional genetic investigations performed after the introduction of anti-IL-1 therapy revealed a pathogenic mosaicism in the NLRP3 gene. After a 12-year follow-up, the patient has not experienced chronic complications. Although genetics is rapidly progressing, this case highlights the importance of early diagnosis of CINCA patients when the clinical and laboratory picture is highly suggestive in order to start the appropriate anti-cytokine treatment even in the absence of a genetic confirmation.

Optimized Treatment of Interleukin (IL-1)-Mediated Autoinflammatory Diseases: Impact of Disease Activity-Based Treatment Adjustments

Background: Effective control of disease activity in Interleukin-1 autoinflammatory diseases (IL-1 AID) is crucial to prevent damage. The aim was to longitudinally analyze the impact of protocolized disease activity-based treatment adjustments in a real-life cohort. Methods: A single-center study of consecutive children with IL-1 AID followed between January 2016 and December 2019 was performed. Demographics, phenotypes, genotypes, inflammatory markers, physician (PGA), and patient/parent (PPGA) global assessment were captured. Disease activity and treatment changes were assessed. The impact of distinct parameters on disease activity trajectories was analyzed. Results: A total of 56 children were included, median follow-up was 2.1 years reflecting 361 visits. Familial Mediterranean Fever was the most common IL-1 AID. At the first visit, 68% of the patients had moderate/severe disease activity. Disease activity-based treatment adjustments were required in 28/56 children (50%). At last follow-up, 79% had a well-controlled disease. Both PGA and PPGA decreased significantly over time (p < 0.001; p < 0.017, respectively), however, both differed statistically at last visit (p < 0.001). Only PGA showed a significant estimated mean decrease across all IL-1 AID over time. Conclusions: Disease activity-based treatment adjustments can effectively refine treat-to-target strategies, enable personalized precision health approaches, and improve outcomes in children with IL-1 AID.

Identifying high-risk neurological phenotypes in adult-onset classic monogenic autoinflammatory diseases: when should neurologists consider testing?

BACKGROUND

Monogenic autoinflammatory disorders result in a diverse range of neurological symptoms in adults, often leading to diagnostic delays. Despite the significance of early detection for effective treatment, the neurological manifestations of these disorders remain inadequately recognized.

METHODS

We conducted a systematic review searching Pubmed, Embase and Scopus for case reports and case series related to neurological manifestations in adult-onset monogenic autoinflammatory diseases. Selection criteria focused on the four most relevant adult-onset autoinflammatory diseases-deficiency of deaminase 2 (DADA2), tumor necrosis factor receptor associated periodic fever syndrome (TRAPS), cryopyrin associated periodic fever syndrome (CAPS), and familial mediterranean fever (FMF). We extracted clinical, laboratory and radiological features to propose the most common neurological phenotypes.

RESULTS

From 276 records, 28 articles were included. The median patient age was 38, with neurological symptoms appearing after a median disease duration of 5 years. Headaches, cranial nerve dysfunction, seizures, and focal neurological deficits were prevalent. Predominant phenotypes included stroke for DADA2 patients, demyelinating lesions and meningitis for FMF, and meningitis for CAPS. TRAPS had insufficient data for adequate phenotype characterization.

CONCLUSION

Neurologists should be proactive in diagnosing monogenic autoinflammatory diseases in young adults showcasing clinical and laboratory indications of inflammation, especially when symptoms align with recurrent or chronic meningitis, small vessel disease strokes, and demyelinating lesions.

Case report: Novel compound heterozygous IL1RN mutations as the likely cause of a lethal form of deficiency of interleukin-1 receptor antagonist

Undiagnosed monogenic diseases represent a challenging group of human conditions highly suspicious to have a genetic origin, but without conclusive evidences about it. We identified two brothers born prematurely from a non-consanguineous healthy couple, with a neonatal-onset, chronic disease characterized by severe skin and bone inflammatory manifestations and a fatal outcome in infancy. We conducted DNA and mRNA analyses in the patients' healthy relatives to identify the genetic cause of the patients' disease. DNA analyses were performed by both Sanger and next-generation sequencing, which identified two novel heterozygous IL1RN variants: the intronic c.318 + 2T>G variant in the father and a ≈2,600-bp intragenic deletion in the mother. IL1RN mRNA production was markedly decreased in both progenitors when compared with healthy subjects. The mRNA sequencing performed in each parent identified two novel, truncated IL1RN transcripts. Additional experiments revealed a perfect intrafamilial phenotype-genotype segregation following an autosomal recessive inheritance pattern. The evidences shown here supported for the presence of two novel loss-of-function (LoF) IL1RN pathogenic variants in the analyzed family. Biallelic LoF variants at the IL1RN gene cause the deficiency of interleukin-1 receptor antagonist (DIRA), a monogenic autoinflammatory disease with marked similarities with the patients described here. Despite the non-availability of the patients' samples representing the main limitation of this study, the collected evidences strongly suggest that the patients described here suffered from a lethal form of DIRA likely due to a compound heterozygous genotype at IL1RN, thus providing a reliable genetic diagnosis based on the integration of old medical information with currently obtained genetic data.

Neutrophilic Urticarial Dermatosis

Neutrophilic urticarial dermatosis (NUD) is a rare form of dermatosis that is poorly understood. It was first described by Kieffer and colleagues as an urticarial eruption that is histopathologically characterized by a perivascular and interstitial neutrophilic infiltrate with intense leukocytoclasia and without vasculitis or dermal edema. NUD clinically presents as a chronic or recurrent eruption that consists of nonpruritic macules, papules, or plaques that are pink to reddish and that resolve within 24 hours without residual pigmentation. NUD is often associated with systemic diseases such as Schnitzler syndrome, lupus erythematosus, adult-onset Still's disease, and cryopyrin-associated periodic syndromes.

Update on ocular manifestations of the main monogenic and polygenic autoinflammatory diseases

Autoinflammatory diseases include disorders with a genetic cause and also complex syndromes associated to polygenic or multifactorial factors. Eye involvement is present in many of them, with different extent and severity. The present review covers ophthalmological lesions in the most prevalent monogenic autoinflammatory diseases, including FMF (familial Mediterranean fever), TRAPS (TNF receptor-associated periodic syndrome), CAPS (cryopyrin-associated periodic syndromes), Blau syndrome, DADA2 (deficiency of adenosine deaminase 2), DITRA (deficiency of the interleukin-36 receptor antagonist), other monogenic disorders, including several ubiquitinopathies, interferonopathies, and the recently described ROSAH (retinal dystrophy, optic nerve edema, splenomegaly, anhidrosis, and headache) syndrome, and VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. Among polygenic autoinflammatory diseases, ocular manifestations have been reviewed in Behçet's disease, PFAPA (periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis) syndrome, Still's disease and autoinflammatory bone diseases, which encompass CRMO (chronic recurrent multifocal osteomyelitis) and SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) syndrome.

Pathogenic variants in the NLRP3 LRR domain at position 861 are responsible for a boost-dependent atypical CAPS phenotype

BACKGROUND

Cryopyrin-associated periodic syndrome (CAPS) is associated with NLRP3 pathogenic variants, mostly located in the NACHT (neuronal apoptosis inhibitor protein, MHC class 2 transcription activator, incompatibility locus protein from Podospora anserina, telomerase-associated protein) domain. Cold-induced urticarial rash is among the main clinical features. However, this study identified a series of 14 patients with pathogenic variants of the Y861 residue (p.Tyr861) of the LRR domain of NLRP3 and minimal prevalence of cold-induced urticarial rash.

OBJECTIVES

This study aimed to address a possible genotype/phenotype correlation for patients with CAPS and to investigate at the cellular levels the impact of the Y861C substitution (p.Tyr861Cys) on NLRP3 activation.

METHODS

Clinical features of 14 patients with CAPS and heterozygous substitution at position 861 in the LRR domain of NLRP3 were compared to clinical features of 48 patients with CAPS and pathogenic variants outside the LRR domain of NLRP3. IL-1β secretion by PBMCs and purified monocytes from patients and healthy donors was evaluated following LPS and monosodium urate crystal stimulation.

RESULTS

Patients with substitution at position 861 of NLRP3 demonstrated a higher prevalence of sensorineural hearing loss while being less prone to skin urticarial. In contrast to patients with classical CAPS, cells from patients with a pathogenic variant at position 861 required an activation signal to secrete IL-1β but produced more IL-1β during the early and late phase of secretion than cells from healthy donors.

CONCLUSIONS

Pathogenic variants of Y861 of NLRP3 drive a boost-dependent oversecretion of IL-1β associated with an atypical CAPS phenotype.

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.

The phenotype and genotype of Chinese adult patients with NLRP3-associated autoinflammatory disease

OBJECTIVES

NLRP3-associated autoinflammatory disease (NLRP3-AID) is a spectrum of autosomal dominant inherited diseases associated with NLRP3 gene mutations. Reports of Chinese NLRP3-AID cases are limited to date. In the present study, we aim to describe the phenotype and genotype of a cohort of Chinese adult NLRP3-AID patients METHODS: This single-center study included sixteen adult patients diagnosed with NLRP3-AID at Department of Rheumatology, Peking Union Medical College Hospital from April 2015 to September 2021. Whole-exome sequencing using next-generation sequencing was performed in each patient. Clinical data and mutational information were compared with a European cohort.

RESULTS

The median age of disease onset was 16 (0-46) years old, and adult-onset was observed in 4 patients (25%). The median time of diagnosis delay was 20 (0-39) years. Five patients (31.3%) had family history of similar symptoms. The most common clinical manifestations were recurrent fever (93.8%), arthralgia/arthritis (81.3%), skin rash (75%), myalgia (62.5%), and central nervous system manifestations (50%). Heterozygous NLRP3 variants detected in these patients were p.T348M (n = 4, 25%), Q703K, V70M, K129R, M116I, P38S, V442I, D303G, G326E, A439V, K829T, L632F and V198M (n = 1, separately). All the variants were missense mutations.

CONCLUSIONS

We reported the largest case series of Chinese adult NLRP3-AID patients. The distinct symptoms of NLRP3-AID patients suggest the heterogeneity of disease. P38S, M116I, K129R, V442I and K829T were identified as novel NLRP3 variants. These data expand the clinical phenotypic and genotypic profiles of NLRP3-AID. Key Points • We characterized the clinical and genetic features of sixteen Chinese adult NLRP3-AID patients. • Thirteen NLRP3 gene variants were confirmed in this cohort, and P38S, M116I, K129R, V442I and K829T were identified as novel variants. • Clinical data and mutation information were compared with a European cohort. • We hope these data would expand the phenotypic and genotypic profile of NLRP3-AID and raise the awareness of early diagnosis and accurate treatment among rheumatologists.

What General Neurologists Should Know about Autoinflammatory Syndromes?

Autoinflammatory disorders encompass a wide range of conditions with systemic and neurological symptoms, which can be acquired or inherited. These diseases are characterized by an abnormal response of the innate immune system, leading to an excessive inflammatory reaction. On the other hand, autoimmune diseases result from dysregulation of the adaptive immune response. Disease flares are characterized by systemic inflammation affecting the skin, muscles, joints, serosa, and eyes, accompanied by unexplained fever and elevated acute phase reactants. Autoinflammatory syndromes can present with various neurological manifestations, such as aseptic meningitis, meningoencephalitis, sensorineural hearing loss, and others. Early recognition of these manifestations by general neurologists can have a significant impact on the prognosis of patients. Timely and targeted therapy can prevent long-term disability by reducing chronic inflammation. This review provides an overview of recently reported neuroinflammatory phenotypes, with a specific focus on genetic factors, clinical manifestations, and treatment options. General neurologists should have a good understanding of these important diseases.

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.

New retinal findings in NLRP3-associated autoinflammatory disease

PURPOSE

To determine whether the rare NLRP3-Associated Autoinflammatory Disease (NLRP3-AID) is associated with retinal changes and to assess the ocular involvement.

METHODS

A retrospective cohort study of 20 patients(40 eyes) diagnosed with rare NLRP3-AID at Peking Union Medical College Hospital, from April 2015 to August 2022. Patients underwent a comprehensive ophthalmological examination, including visual acuity, intraocular pressure examination, slit-lamp examination, fundus photography, optical coherence tomography(OCT), and fluorescence angiography (FA). Some patients also underwent optical coherence tomography angiography (OCTA).

RESULTS

This study analyzed 40 eyes of 20 patients (11 [55.0%] male; median age, 25.0 years [range, 12-52 years]) and 13 patients (26 eyes, 65%) demonstrated ocular involvement. The most common ophthalmologic manifestation was conjunctivitis (22 eyes, 84.6%), followed by papilledema (14 eyes, 53.8%), retinopathy (10 eyes, 38.5%), optic atrophy (6 eyes, 23.1%), uveitis (4 eyes, 15.4%), reduced pupil light reflex (3 eyes, 11.5%) and cataracts (2 eyes, 7.7%). Ocular involvement was bilateral in 11 patients (55.0%). Five kinds of retinal lesions were seen in 5 patients (10 eyes, 25%) with NLRP3-AID, including peripheral retinal vascular leakage, microaneurysms, macular ischemia, macular epiretinal membrane formation and drusen.

CONCLUSIONS

Peripheral retinal vascular leakage, macular ischemia, microaneurysms and drusen are newly identified retinal findings in patients with NLRP3-AID, which suggests the importance of detailed retinal examination in these patients.

Inflammasomes and Atherosclerosis: a Mixed Picture

The CANTOS (Canakinumab Anti-inflammatory Thrombosis Outcome Study) and colchicine trials suggest an important role of inflammasomes and their major product IL-1β (interleukin 1β) in human atherosclerotic cardiovascular disease. Moreover, studies in mouse models indicate a causal role of inflammasomes and IL-1β in atherosclerosis. However, recent studies have led to a more granular view of the role of inflammasomes in atherosclerosis. Studies in hyperlipidemic mouse models suggest that prominent activation of the NLRP3 inflammasome requires a second hit such as defective cholesterol efflux, defective DNA repair, clonal hematopoiesis or diabetes. Similarly in humans some mutations promoting clonal hematopoiesis increase coronary artery disease risk in part by promoting inflammasome activation. Recent studies in mice and humans point to a wider role of the AIM2 (absent in melanoma 2) inflammasome in promoting cardiovascular disease including in some forms of clonal hematopoiesis and diabetes. These developments suggest a precision medicine approach in which treatments targeting inflammasomes or IL-1β might be best employed in clinical settings involving increased inflammasome activation.

The assessment of autoinflammatory disease classification criteria (Eurofever/PRINTO) in a real-life cohort

OBJECTIVE

The aim of the study was to determine the sensitivity and specificity rates of Eurofever/PRINTO autoinflammatory recurrent fever classification criteria with real-life data in patients with an autoinflammatory disease.

METHODS

A total of 119 patients were included in the study. Based on clinical symptoms, they were divided into four subgroups: cryopyrin-associated periodic syndromes (CAPS), TNF receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD), and syndrome of undifferentiated recurrent fever (SURF) using the Eurofever/PRINTO clinical classification criteria. In the last step, the patients were re-evaluated in the light of genetic results and their final diagnosis was reached.

RESULTS

A total of 119 patients, including 37 CAPS, 13 TRAPS, 8 MKD, 39 SURF, 14 NLRP12-related autoinflammatory disease (NLRP12-AID), and 8 familial Mediterranean fever (FMF) patients were evaluated in the study. While the sensitivity of the new clinical Eurofever/PRINTO criteria was 48% for CAPS, 77% for TRAPS, 87.5%for MKD, and the specificity of the clinical criteria was 86% for CAPS, 85% for TRAPS, and 60% for MKD. The sensitivity of the new mixed (genetic plus clinical variables) Eurofever/PRINTO criteria was 27% for CAPS, 61% forTRAPS, 85% for MKD, and the specificity of the mixed criteria for each group was 100%.

CONCLUSION

We found the sensitivity of the Eurofever/PRINTO classification criteria to be low as genotypic changes between populations cause phenotypic differences. For this reason, we think that patient-based evaluation is correct rather than standard classification criteria in real life. Key-points • In systemic autoinflammatory diseases, common variants in the populations may alter the phenotype, and making it difficult to classify some patients with the current classification criteria. • In populations with common genetic variants, the classification criteria should be modified according to the clinical phenotype.

Identification of a variant in NLRP3 gene in a patient with Muckle-Wells syndrome: a case report and review of literature

BACKGROUND

Cryopyrin-associated periodic syndrome (CAPS), a rare genetic autoimmune disease, is composed of familial cold autoinflammatory syndrome (FCAs), Muckle-Wells syndrome (MWS), and neonatal onset multisystem inflammatory disease (NOMID). MWS is caused by dominantly inherited or de novo gain-of-function mutations in the NOD-like receptor 3 (NLRP3) gene. At present, there is no report about the variation of R262W in China.

CASE PRESENTATION

We reported a 3-year-old Chinese boy who had recurrent fever without obvious inducement, bilateral conjunctival congestion, and urticarial-like rash. Laboratory examination showed elevation in leukocyte count, neutrophil count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) and serum amyloid protein (SAA) levels. Whole exome sequencing identified a missense variation c.784-786delinsTGG (p.R262W) in the coding region of the NLRP3 gene.

CONCLUSION

A classical variant of the NLRP3 gene in a patient with MWS was first reported in China.

A unique presentation of NLRP3-associated autoinflammatory disease: case report

BACKGROUND

NLRP3-associated autoinflammatory diseases (NLRP3-AID) are rare genetic autoinflammatory diseases characterized by chronic inflammation and an urticaria-like rash. We report an unusual presentation of severe NLRP3-AID resulting in a significant diagnostic delay of more than three decades.

CASE PRESENTATION

The patient presented with early-onset serositis as well as prominent peripheral eosinophilia with organ infiltration, in the absence of the classic urticaria-like rash. DNA analysis by next generation sequencing revealed a sporadic class 4 mutation c.1991T > C (p.Met662Thr) in the NLRP3 gene, confirming a diagnosis of NLRP3-AID at 36 years old. Although treatment with anti-interleukin 1 agent led to clinical remission, irreversible sequelae, namely intellectual disability and deafness, remained.

CONCLUSION

This case highlights unique manifestations of NLRP3-AID, namely the absence of urticaria-like rash, eosinophilic organ infiltration, and pseudoseptic serositis. In order to avoid diagnostic delay and its dire consequences, NLRP3-AID should be suspected in patients displaying autoinflammatory features combined with serum and tissue eosinophilia and/or marked serositis, regardless of skin involvement.

AA amyloidosis complicating cryopyrin-associated periodic syndrome: a study of 86 cases including 23 French patients and systematic review

OBJECTIVE

Cryopyrin-associated periodic syndrome (CAPS) is a rare but treatable inherited autoinflammatory condition including familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS) and chronic infantile neurologic cutaneous articular syndrome (CINCA). Our objective was to describe the main features of CAPS AA amyloidosis (AA-CAPS) associated and the efficacy of IL-1 inhibitors in this indication.

METHODS

Retrospective study in France associated with a systematic literature review.

RESULTS

Eighty-six patients were identified: 23 new French cases and 63 from the literature, with a median age at amyloidosis diagnosis of 39 years old. CAPS subtypes were MWS (n = 62), FCAS (n = 9), frontier forms between MWS and FCAS (n = 12) and between CINCA and MWS (n = 3). NLRP3 had been sequenced in 60 patients (70%) and the most frequent mutation was R260W (60%). Three AA-CAPS patients displayed somatic NLRP3 mutations. Death occurred in 35 patients (41%), none of whom having ever received IL-1 inhibitors. Twenty-eight patients (33%) received IL-1 inhibitors, with a >50% decrease in proteinuria in 89% of cases.

CONCLUSION

AA amyloidosis can occur in nearly all CAPS subtypes. IL-1 inhibitors are effective, underlining the necessity of an early diagnosis of CAPS in order to start this treatment as soon as possible among AA-CAPS patients.

The relation between C-reactive protein and serum amyloid A in patients with autoinflammatory diseases

BACKGROUND

Autoinflammatory diseases are rare disorders of the innate immune system characterized by fever and other signs of inflammation. A feared complication of autoinflammatory diseases is the development of AA amyloidosis. AA amyloidosis is caused by extracellular deposition of soluble serum amyloid A (SAA) proteins as insoluble amyloid fibrils leading to organ damage. Prolonged high levels of SAA are a prerequisite to develop AA amyloidosis. Since measurement of SAA is relatively expensive and sometimes unavailable, C-reactive protein (CRP) is often used as a surrogacy marker to test for inflammation.

OBJECTIVE

The aim of this research is to evaluate the possible relation between CRP and SAA.

METHODS

A retrospective cohort of patients with autoinflammatory diseases (n = 99) where SAA and CRP blood testing was performed in the period between 2015 and 2021 in the University Medical Centre in Groningen was used to investigate the correlation between CRP and SAA.

RESULTS

CRP and SAA have a high correlation (rho = 0.755, p < 0.001). A CRP value below 0.45 mg/L results in 100% sensitivity for SAA below 4 mg/L. CRP below 5 mg/L is a good predictor of SAA below 4 mg/L with 85.4% sensitivity and 83.6% specificity. Only prednisone and erythrocyte sedimentation rate (ESR) significantly influence the relation between CRP and log₁₀SAA.

CONCLUSION

There was a significant correlation between CRP and SAA in our retrospective cohort. CRP levels below 5 mg/L proved to be highly predictive of SAA levels below 4 mg/L. This may not be true for patients on steroids.

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)-1β 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-1β 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.

Tapering of biological treatment in autoinflammatory diseases: a scoping review

BACKGROUND

Biological treatment and treat-to-target approaches guide the achievement of inactive disease and clinical remission in Autoinflammatory Diseases (AID). However, there is limited evidence addressing optimal tapering strategies and/or discontinuation of biological treatment in AID. This study evaluates available evidence of tapering biological treatment and explores key factors for successful tapering.

METHODS

A systematic literature search was conducted in Embase, MEDLINE, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials using the OVID platform (1990-08/2020). Bibliographic search of relevant reviews was also performed. Studies/case series (n ≥ 5) in AID patients aged ≤ 18 years with biological treatment providing information on tapering/treatment discontinuation were included. After quality assessment aggregated data were extracted and synthesized. Tapering strategies were explored.

RESULTS

A total of 6035 records were identified. Four papers were deemed high quality, all focused on systemic juvenile idiopathic arthritis (sJIA) (1 open-label randomized trial, 2 prospective, 1 retrospective observational study). Biological treatment included anakinra (n = 2), canakinumab (n = 1) and tocilizumab (n = 1). Strategies in anakinra tapering included alternate-day regimen. Canakinumab tapering was performed randomized for dose reduction or interval prolongation, whereas tocilizumab was tapered by interval prolongation. Key factors identified included early start of biological treatment and sustained inactive disease.

CONCLUSION

Tapering of biological treatment after sustained inactive disease should be considered. Guidance for optimal strategies is limited. Future studies may leverage therapeutic drug monitoring in combination with pharmacometric modelling to further enhance personalized "taper-to-target" strategies respecting individual patients and diseases aspects.

Periodic Fever in Children: Etiology and Diagnostic Challenges

Periodic fever in children is an autoinflammatory illness with an unknown cause. Symptoms include frequent episodes of fever that are followed by an increase in inflammatory markers. A genetic background for periodic fever of unknown origin has been hypothesized, based on its family clustering and parallels to other autoinflammatory illnesses such as familial Mediterranean fever. Genome analysis has been used in studies to look for related gene variations in periodic fever of unknown origin in the pediatric population. 

Children with periodic fevers might be a diagnostic challenge. After ruling out the most prevalent causes, a wide variety of other possibilities are investigated. Infectious and noninfectious causes of periodic fever in children are discussed in this article.

Inflammasomes (intracellular proteins that activate interleukin (IL)-1b and IL-18) and genetic/hereditary variations are thought to be implicated in the pathogenesis of periodic fever. Evaluation and ruling out possible infective or noninfective causes is vital in the diagnosis of periodic fever in children. Investigations demonstrate that there isn't a single gene linked to it, suggesting that it may have a multifactorial or polygenic origin, with an environmental trigger causing inflammasome activation and fever flares. Treatment is usually symptomatic, with drugs such as colchicine and cimetidine having shown promising results in trials.

We explored the literature on periodic fever in children for its epidemiology, pathophysiology, the role of various genes and how they influence the disease and associated complications, and its various treatment modalities.

A three-generation Muckle-Wells syndrome family: Detailed family history, physical examination, and inter-departmental collaboration

Cryopyrin-associated periodic syndrome (CAPS) is a rare inherited autoinflammatory disease caused by gain-of-function mutations in the NLRP3 gene, with a genotype-phenotype correlation. The clinical presentation of each mutation has been previously studied. However, very few studies have reported on the clinical characteristics and treatment effectiveness across different generations within a family with the same mutation. A detailed investigation of family members of patients with CAPS may help in the appropriate diagnosis and treatment of undiagnosed CAPS. Herein, we report a 2-year-old boy (proband), his father, and his grandmother who presented with several symptoms of CAPS, such as persistently positive inflammatory reactions and hearing impairment. All three patients had the same pathogenic mutation in the NLRP3 gene (c.1049C > T (p.Thr350Met) heterozygous mutation) and were diagnosed with CAPS. With canakinumab treatment, the laboratory data of all three patients improved, the proband and father's skin rash disappeared, and his grandmother's arthropathy improved. The proband's hearing also showed slight improvement but not in his father or grandmother. Among the various non-specific symptoms associated with CAPS, chronic ocular hyperaemia is a finding that can be easily identified by non-ophthalmologists. Diagnosis of CAPS should be considered when eye symptoms are present in a combination of hyperinflammatory response, arthropathy, or skin symptoms. Thorough family history records, physical examinations, and close collaboration between paediatricians and adult rheumatologists are important for prompt diagnosis and appropriate treatment of inherited autoinflammatory diseases.

Clinical and genetic spectrum of 14 cases of NLRP3-associated autoinflammatory disease (NLRP3-AID) in China and a review of the literature

BACKGROUND

NLRP3-associated autoinflammatory disease (NLRP3-AID), caused by mutations of NLRP3, is one of the autoinflammatory diseases affecting inflammasomes. Since there are little cases of Chinese NLRP3-AID, we reported 14 Chinese NLRP3-AID patients in our center and summarized the clinical features of all Chinese patients by reviewing the literature.

RESULTS

Fourteen patients had been diagnosed as NLRP3-AID in our center. 12 different NLRP3 variants were identified, among which one is novel: p.Leu361Trp. Rash, recurrent fever, arthritis/arthralgia, uveitis, sensorineural deafness, symptoms of central neural systems (CNS), and increased inflammatory markers (including CRP, ESR, except Ferritin) were the common findings in Chinese patients. The frequencies of fever, neurological symptoms, musculoskeletal manifestations and ocular manifestations in Chinese patients might differ from that of patients from other regions. Besides, we also found clubbing fingers and optic neuritis in some NLRP3-AID patients, which were not commonly mentioned in previous reports.

CONCLUSION

In our study, we expanded the clinical spectrum as well as the genetic pathogenic variants of NLRP3-AID. We also found that there were some differences between Chinese patients and patients from other regions, and that Chinese patients were more likely to develop severe symptoms.

The 2021 EULAR/American College of Rheumatology Points to Consider for Diagnosis, Management and Monitoring of the Interleukin-1 Mediated Autoinflammatory Diseases: Cryopyrin-Associated Periodic Syndromes, Tumour Necrosis Factor Receptor-Associated Periodic Syndrome, Mevalonate Kinase Deficiency, and Deficiency of the Interleukin-1 Receptor Antagonist

BACKGROUND

The interleukin-1 (IL-1) mediated systemic autoinflammatory diseases, including the 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), belong to a group of rare immunodysregulatory diseases that primarily present in early childhood with variable multiorgan involvement. When untreated, patients with severe clinical phenotypes have a poor prognosis, and diagnosis and management of these patients can be challenging. However, approved treatments targeting the proinflammatory cytokine IL-1 have been life changing and have significantly improved patient outcomes.

OBJECTIVE

To establish evidence-based recommendations for diagnosis, treatment and monitoring of patients with IL-1 mediated autoinflammatory diseases to standardise their management.

METHODS

A multinational, multidisciplinary task force consisting of physician experts, including rheumatologists, patients or caregivers and allied healthcare professionals, was established. Evidence synthesis, including systematic literature review and expert consensus (Delphi) via surveys, was conducted. Consensus methodology was used to formulate and vote on statements to guide optimal patient care.

RESULTS

The task force devised five overarching principles, 14 statements related to diagnosis, 10 on therapy, and nine focused on long-term monitoring that were evidence and/or consensus-based for patients with IL-1 mediated diseases. An outline was developed for disease-specific monitoring of inflammation-induced organ damage progression and reported treatments of CAPS, TRAPS, MKD and DIRA.

CONCLUSION

The 2021 EULAR/American College of Rheumatology points to consider represent state-of-the-art knowledge based on published data and expert opinion to guide diagnostic evaluation, treatment and monitoring of patients with CAPS, TRAPS, MKD and DIRA, and to standardise and improve care, quality of life and disease outcomes.

The 2021 EULAR/American College of Rheumatology points to consider for diagnosis, management and monitoring of the interleukin-1 mediated autoinflammatory diseases: cryopyrin-associated periodic syndromes, tumour necrosis factor receptor-associated periodic syndrome, mevalonate kinase deficiency, and deficiency of the interleukin-1 receptor antagonist

BACKGROUND

The interleukin-1 (IL-1) mediated systemic autoinflammatory diseases, including the 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), belong to a group of rare immunodysregulatory diseases that primarily present in early childhood with variable multiorgan involvement. When untreated, patients with severe clinical phenotypes have a poor prognosis, and diagnosis and management of these patients can be challenging. However, approved treatments targeting the proinflammatory cytokine IL-1 have been life changing and have significantly improved patient outcomes.

OBJECTIVE

To establish evidence-based recommendations for diagnosis, treatment and monitoring of patients with IL-1 mediated autoinflammatory diseases to standardise their management.

METHODS

A multinational, multidisciplinary task force consisting of physician experts, including rheumatologists, patients or caregivers and allied healthcare professionals, was established. Evidence synthesis, including systematic literature review and expert consensus (Delphi) via surveys, was conducted. Consensus methodology was used to formulate and vote on statements to guide optimal patient care.

RESULTS

The task force devised five overarching principles, 14 statements related to diagnosis, 10 on therapy, and nine focused on long-term monitoring that were evidence and/or consensus-based for patients with IL-1 mediated diseases. An outline was developed for disease-specific monitoring of inflammation-induced organ damage progression and reported treatments of CAPS, TRAPS, MKD and DIRA.

CONCLUSION

The 2021 EULAR/American College of Rheumatology points to consider represent state-of-the-art knowledge based on published data and expert opinion to guide diagnostic evaluation, treatment and monitoring of patients with CAPS, TRAPS, MKD and DIRA, and to standardise and improve care, quality of life and disease outcomes.

Auditory and Vestibular Characteristics of NLRP3 Inflammasome Related Autoinflammatory Disorders: Monogenic Hearing Loss Can Be Improved by Anti-interleukin-1 Therapy

Inflammasomes are large multimeric protein complexes which regulate the activation of the proinflammatory cytokines interleukins-1β and−18 and inflammatory cell death called pyroptosis. NLRP1, NLRP3, NLRC4, AIM2, and pyrin can induce the formation of inflammasomes. Of these, the NLRP3 inflammasome is the most well-characterized. Recent studies revealed that variants of the NLRP3 gene cause genetic diseases, including systemic inflammatory syndrome called cryopyrin-associated periodic syndrome (CAPS) and non-syndromic sensorineural hearing loss DFNA34. NLRP3 variants cause CAPS and DFNA34 by constitutively activating the NLRP3 inflammasome and increasing IL-1β release. Patients with CAPS show systemic inflammatory symptoms, and hearing loss is a characteristic feature. Patients with CAPS and DFNA34 show progressive bilateral sensorineural hearing loss. Hearing loss has unique characteristics that can be improved or stabilized by anti-interluekin-1 therapy, although it is usually difficult to alleviate genetic hearing loss by drugs. However, it should be noted that there is a window of opportunity to respond to treatment, and younger patients are most likely to respond. It is important to know the characteristics of CAPS and DFNA34 for early diagnosis, and mutation analysis of NLRP3 will lead to a definite diagnosis. In this review, we summarize the current understanding of the mechanisms of the NLRP3 inflammasome and characteristics of patients with CAPS and DFNA34, especially focused on auditory and vestibular findings.

A 9-Year-Old Patient with Recurrent Fever, Urticarial Rash and Demyelinating Brain Lesions: NLRP3-Autoinflammatory Disease in Ecuador

Autoinflammatory diseases (AIDs) are a relatively new family disorders defined approximately 20 years ago. AIDs are caused by defect(s) or dysregulation of the innate immune system, characterized by recurrent or continuous inflammation and lack of a primary pathogenic role for the adaptive immune system. One AID, NLRP3-associated autoinflammatory disease (NLRP3-AID), involves a clinical presentation since the neonatal period or childhood, with multiple inflammatory recurrent symptoms that appear throughout the patient´s life. We present the first case of NLRP3-AID in Ecuador. The patient presented recurrent fever since 6 months of age associated with urticarial rash, arthralgias, and abdominal pain; recently, he had a seizure at 7 years of age. Brain MRI revealed demyelinating lesions, and genetic testing uncovered a de novo mutation in the NLRP3 gene. The patient had a good clinical response to treatment with canakinumab.

Neuroinflammation Associated With Inborn Errors of Immunity

The advent of high-throughput sequencing has facilitated genotype-phenotype correlations in congenital diseases. This has provided molecular diagnosis and benefited patient management but has also revealed substantial phenotypic heterogeneity. Although distinct neuroinflammatory diseases are scarce among the several thousands of established congenital diseases, elements of neuroinflammation are increasingly recognized in a substantial proportion of inborn errors of immunity, where it may even dominate the clinical picture at initial presentation. Although each disease entity is rare, they collectively can constitute a significant proportion of neuropediatric patients in tertiary care and may occasionally also explain adult neurology patients. We focus this review on the signs and symptoms of neuroinflammation that have been reported in association with established pathogenic variants in immune genes and suggest the following subdivision based on proposed underlying mechanisms: autoinflammatory disorders, tolerance defects, and immunodeficiency disorders. The large group of autoinflammatory disorders is further subdivided into IL-1β-mediated disorders, NF-κB dysregulation, type I interferonopathies, and hemophagocytic syndromes. We delineate emerging pathogenic themes underlying neuroinflammation in monogenic diseases and describe the breadth of the clinical spectrum to support decisions to screen for a genetic diagnosis and encourage further research on a neglected phenomenon.

Somatic Mutations in Rheumatologic Diseases: VEXAS Syndrome and Beyond

Discovery of the VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome demonstrates that somatic mutations in hematologic precursor cells can cause adult-onset, complex inflammatory disease. Unlike germline mutations, somatic mutations occur throughout the lifespan, are restricted to specific tissue types, and may play a causal role in non-heritable rheumatologic diseases, especially conditions that start in later life. Improvements in sequencing technology have enabled researchers and clinicians to detect somatic mutations in various tissue types, especially blood. Understanding the relationships between cell-specific acquired mutations and inflammation is likely to yield key insights into causal factors that underlie many rheumatologic diseases. The objective of this review is to detail how somatic mutations are likely to be relevant to clinicians who care for patients with rheumatologic diseases, with particular focus on the pathogenetic mechanisms of the VEXAS syndrome.

[Autoinflammation-differences between children and adults]

Autoinflammatory diseases present as multisystemic inflammation and often manifest in early childhood. In contrast, in a few diseases, e.g., the recently described VEXAS (vacuoles, E1 enzyme, X‑linked, autoinflammatory, somatic) syndrome, the first symptoms occur exclusively in adulthood. This article describes how the phenotypic expression and severity of individual autoinflammatory diseases differ depending on age. Furthermore, differences in the development of organ damage in children and adults are pointed out. In addition to the hereditary periodic fever syndromes, the clinical picture of deficiency of adenosine deaminase 2, the interferonopathies, periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome as well as VEXAS and Schnitzler syndromes are highlighted.