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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.

Objective: Cryopyrin-associated periodic syndrome (CAPS) is characterized by excessive IL-1β release resulting in systemic and organ inflammation. As an anti-IL-1 agent, canakinumab has been approved with all CAPS phenotypes in USA and European countries. However, the use of canakinumab in CAPS in Chinese patients was rarely reported. In this study, we aimed to assess the effectiveness and safety of canakinumab in Chinese patients with CAPS. Methods: Patients with CAPS treated with canakinumab were included. Clinical data were collected retrospectively from medical records. Treatment response was evaluated by CAPS disease activity score, C-reactive protein (CRP), and/or serum amyloid A (SAA) levels. Data was analyzed at canakinumab initiation, at months 1, 3, 6, 9, and 12, or the last follow-up. Results: A total of 10 CAPS patients were included. 40% of patients were males, the median age at disease onset was 2.5 (2.5, 6) days and the median duration of follow-up while on canakinumab was 22.5 (8.5, 27.5) months. 80% (8/10) of CAPS patients presented with moderate-severe disease activity before the canakinumab treatment. 30% (3/10) of patients required canakinumab dose increase to control disease activity. After treatments, 60% (6/10) of CAPS patients achieved complete remission without relapse and the rest showed minimal disease activity. Clinical symptoms such as fever and rash were improved significantly in most patients (80%). Although abnormal imaging in brain MRI remained in over half of those patients, neurological manifestations were all relieved. 60% (6/10) of patients received prednisone before starting canakinumab therapy and five of them discontinued prednisone later. The most common adverse event was infection (40%). No serious adverse events occurred during the treatment of canakinumab. Conclusions: Canakinumab may be effective and tolerable for Chinese CAPS patients, helping to reduce the dosage of corticosteroids. However, additional trials on large samples are required to further evaluate its efficacy and safety in China. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract Objective Cryopyrin-associated periodic syndrome (CAPS) is characterized by excessive IL-1β release resulting in systemic and organ inflammation. As an anti-IL-1 agent, canakinumab has been approved with all CAPS phenotypes in USA and European countries. However, the use of canakinumab in CAPS in Chinese patients was rarely reported. In this study, we aimed to assess the effectiveness and safety of canakinumab in Chinese patients with CAPS. Methods Patients with CAPS treated with canakinumab were included. Clinical data were collected retrospectively from medical records. Treatment response was evaluated by CAPS disease activity score, C-reactive protein (CRP), and/or serum amyloid A (SAA) levels. Data was analyzed at canakinumab initiation, at months 1, 3, 6, 9, and 12, or the last follow-up. Results A total of 10 CAPS patients were included. 40% of patients were males, the median age at disease onset was 2.5 (2.5, 6) days and the median duration of follow-up while on canakinumab was 22.5 (8.5, 27.5) months. 80% (8/10) of CAPS patients presented with moderate-severe disease activity before the canakinumab treatment. 30% (3/10) of patients required canakinumab dose increase to control disease activity. After treatments, 60% (6/10) of CAPS patients achieved complete remission without relapse and the rest showed minimal disease activity. Clinical symptoms such as fever and rash were improved significantly in most patients (80%). Although abnormal imaging in brain MRI remained in over half of those patients, neurological manifestations were all relieved. 60% (6/10) of patients received prednisone before starting canakinumab therapy and five of them discontinued prednisone later. The most common adverse event was infection (40%). No serious adverse events occurred during the treatment of canakinumab. Conclusions Canakinumab may be effective and tolerable for Chinese CAPS patients, helping to reduce the dosage of corticosteroids. However, additional trials on large samples are required to further evaluate its efficacy and safety in China.

This article discusses a case of cryopyrin-associated periodic syndrome (CAPS) and psoriasis in a 64-year-old man. CAPS is a rare autoinflammatory disease caused by genetic variants, and the article highlights the challenges in diagnosing it. The patient exhibited symptoms such as fever, arthritis, and skin rash, but not other typical CAPS symptoms. The article suggests a potential relationship between CAPS and psoriasis and calls for further research on this topic. Treatment with a Janus kinase inhibitor was effective against the skin rash but less effective against arthralgia. [Extracted from the article]

Granulomatous tubulointerstitial nephritis (GTIN) attributed to early onset sarcoidosis is an ultrarare finding in an allograft kidney biopsy. We present the case of a young man with allograft dysfunction who had GTIN upon biopsy. We performed a thorough case review based on recovered records from early childhood and reassessed genetic testing results. We revised his underlying diagnosis from cryopyrin-associated periodic syndrome to early-onset sarcoidosis with wild-type NOD2 and established a rationale to use the interleukin-6 (IL-6) receptor blocker tocilizumab (TCZ). This suppressed his inflammatory disease and stabilised kidney function. We performed a literature review related to the emerging role of IL-6 pathway blockade in kidney transplantation. We identified 18 reports with 417 unique patients treated with TCZ for indications including HLA-desensitisation, transplant immunosuppression induction, treatment of chronic antibody-mediated rejection, and treatment of subclinical rejection. Both TCZ and the direct IL-6 inhibitor clazakizumab are being studied in ongoing randomised control trials. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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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‐1β 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‐1β 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‐1β 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. [ABSTRACT FROM AUTHOR]

Objectives: Cryopyrin-associated periodic syndrome or NLRP3-associated autoinflammatory disease (NLRP3-AID) and NLRP12-AID are both Mendelian disorders with autosomal dominant inheritance. Both diseases are rare, primarily reported in the pediatric population, and are thought to be phenotypically indistinguishable. We provide the largest cohort of adult-onset patients and compared these diseases and the gene variant frequency to population controls. Methods: A cohort of adult patients with AIDs were retrospectively studied. All underwent molecular testing for periodic fever syndrome gene panels after extensive and negative workups for systemic autoimmune and other related diseases. Patients were divided into Group 1-NLRP3-AID patients with NLRP3 variants (N=15), Group 2-NLRP12-AID with NLRP12 variants (N=14) and Group 3-both NLRP3 and NLRP12 (N=9) variants. Exome sequence data of two large control populations including the ARIC study were used to compare gene variant distribution and frequency. Results: All 38 patients were Caucasian with women accounting for 82%. Median age at diagnosis was 41 ± 23 years and the disease duration at diagnosis was 14 ± 13 years. We identified statistically significant differences between the groups, notably that gastrointestinal symptoms as well as evaluations for same were significantly more frequent in patients with NLRP12 variants, and headaches/dizziness were less common among the NLRP12 patients. Livedo reticularis was noted in four patients, exclusively among NLRP12 carriers. Over 50% of patients in Groups 1 and 2 carry low-frequency disease-associated variants, while the remaining carry rare variants. We unprecedently identified digenic variants, i.e., the coexistence of NLRP3 and NLRP12, which were either both low frequency or low frequency/rare. Allele frequencies of all variants identified in our cohort were either absent or significantly lower in the control populations, further strengthening the evidence of susceptibility of these variants to SAID phenotypes. Conclusion: Our comparative study shows that both NLRP3-AID and NLRP12-AID share similar clinical phenotypes, yet there are significant differences between them with regard to gastrointestinal and neurological symptoms. A spectrum of high to low genetic variations in both genes can contribute to SAID individually or in combination. [ABSTRACT FROM AUTHOR]

NOD-like receptor family, pyrin domain-containing 3 (NLRP3) is a central protein contributing to human inflammatory disorders, including cryopyrin-associated periodic syndrome and sepsis. However, the molecular mechanisms and functions of NLRP3 activation in various diseases remain unknown. Here, we generated gain-of-function knock-in mice associated with Muckle–Wells syndromes using the Cre-LoxP system allowing for the constitutive T346M mutation of NLRP3 to be globally expressed in all cells under the control of tamoxifen. The mice were treated with tamoxifen for 4 days before determining their genotype by PCR and sequence analysis. In vitro, we found that bone marrow-derived macrophage from homozygous T346M mutation mice displayed a robust ability to produce IL-1β in response to lipopolysaccharide exposure. Moreover, ASC specks and oligomerization were observed in the homozygous mutant bone marrow-derived macrophages in the presence of lipopolysaccharides alone. Mechanistically, K+ and Ca2+ depletion and mitochondrial depolarization contribute to the hyperactivation of mutant NLRP3. In vivo, homozygous mice carrying the T346M mutation exhibit weight loss and mild inflammation in the resting state. In the lipopolysaccharide-mediated sepsis model, homozygous mutant mice exhibited higher mortality and increased serum circulating cytokine levels, accompanied by serious liver injury. Furthermore, an increase in myeloid cells in the spleen has been suggested to be a risk factor for inducing sepsis sensitivity. Altogether, we describe a cryopyrin-associated syndrome animal model with the T346M mutation of NLRP3 and suggest that the hyperactivated inflammasome aggregated by the mutant NLRP3 lowers the inflammatory response threshold both in vitro and in vivo. A novel tamoxifen-inducible Nlrp3 knock-in mouse line was generated using Cre-LoxP strategy. The hyperactive NLRP3 inflammasome caused by the missense mutation T346M exacerbated the immune response in macrophages and septic mice. Graphical Abstract [ABSTRACT FROM AUTHOR]

To investigate clinical symptoms and genetic variants in patients from the German anti-IL-1 registry for autoinflammatory orphan diseases (GARROD) between 2013 and 2022. Multicentre, retrospective analysis of demographic, clinical and genetic data of patients with autoinflammatory diseases (AID) who received anti-IL-1 targeted therapy. The cohort comprised 152 patients with familial Mediterranean fever (FMF; n = 71), cryopyrin-associated periodic syndromes (CAPS; n = 43), TNF-receptor associated periodic syndrome (TRAPS; n = 19), mevalonate kinase deficiency (MKD; n = 3) and unclassified AID (uAID; n = 16). Inflammatory attacks started in 61.2% of the patients before the age of 18 years. The delay between the first AID attack and anti-IL-1 therapy was 17.8 years. Monogenetic AIDs were diagnosed by clinical symptoms. Genetic analyses confirmed the diagnosis in 87.3% of patients with FMF, 65.2% with CAPS and 94.8% with TRAPS. Among this group, heterozygous MEFV variants and variants of unknown significance (VUS) were detected in 22.5% of patients with FMF, 51.2% with CAPS and 47.4% with TRAPS. Patients with VUS were older at disease onset which is consistent with a milder phenotype. Twenty-four patients had secondary AA amyloidosis (AA) at initiation of anti-IL-1 therapy. The mean age of these patients was 16.4 years at their first attack and 44.9 years at the time of AA diagnosis. Turkish-Armenian ancestry correlated with MEFV variants and higher FMF disease activity compared to German ancestry. Molecular genetic analyses should substantiate the clinical diagnosis of a monogenetic AID. Our data support the concept of variable penetrance of VUS which can be associated with late-onset AID. [ABSTRACT FROM AUTHOR]

In most of these unknown cases, it's not that I'm completely lost. I know in a general sense that there is an inflammatory disease present. I know that there doesn't appear to be cancer in the background, or infection. I have a lengthy list of conditions that the patient does not have. But one of my most difficult tasks when I sit down with a patient at a follow-visit is to take a deep breath, adjust my glasses and admit that I don't know what's wrong." Charles Radis. The rheumatologist as detective. The Rheumatologist, 1 Feb 2015. Patients with periodic inflammation who remain undiagnosed after initial rational and targeted investigation pose a clinical conundrum. This editorial presents an approach to these cases and focuses on the recognition and diagnosis of systemic autoinflammatory diseases (SAIDs). This approach utilises genetic testing for SAIDs, recognising the presentations of non-genetic SAIDs, and empiric trials of therapy in suspected inflammatory disease. Ultimately, not achieving a final diagnosis is very common and the clinician's role is to help manage the uncertainty around this through support, follow-up and reassurance. [ABSTRACT FROM AUTHOR]

Patients with systemic autoinflammatory diseases (sAIDs) are a section of the population at high risk of severe COVID-19 outcomes, but evidence on the efficacy of SARS-CoV-2 vaccination in this group of patients is scarce. To investigate the efficacy of SARS-CoV-2 vaccination in patients with sAIDs receiving interleukin-1 (IL-1) inhibition is important. Vaccination and infection responses from 100 sAID patients and 100 healthy controls (HCs) were analyzed. In total, 98% of patients were treated with IL-1 inhibitors at the time of vaccination (n = 98). After the second SARS-CoV-2 vaccination, sAID patients showed similar anti-SARS-CoV-2 antibody responses (mean (standard deviation (SD)): 6.7 (2.7)) compared to HCs (5.7 (2.4)) as well as similar neutralizing antibodies (85.1 ± 22.9% vs. 82.5 ± 19.7%). Anti-SARS-CoV-2 antibody responses and neutralizing antibodies were similar in sAID patients after SARS-CoV-2 infection and double vaccination. Furthermore, while antibodies increased after the first and second vaccination in sAID patients, they did not further increase after the third and fourth vaccination. No difference was found in antibody responses between anakinra and anti-IL-1 antibody treatment and the additional use of colchicine or other drugs did not impair vaccination responses. Primary and booster SARS-CoV-2 vaccinations led to protective antibody responses in sAID patients, which were at the same level of vaccination responses in HCs and in sAID patients after SARS-CoV-2 infection. Immunomodulatory treatments used in sAID do not seem to affect antibody responses to the SARS-CoV-2 vaccine. [ABSTRACT FROM AUTHOR]

ObjectivesCryopyrin-associated periodic syndrome or NLRP3-associated autoinflammatory disease (NLRP3-AID) and NLRP12-AID are both Mendelian disorders with autosomal dominant inheritance. Both diseases are rare, primarily reported in the pediatric population, and are thought to be phenotypically indistinguishable. We provide the largest cohort of adult-onset patients and compared these diseases and the gene variant frequency to population controls.MethodsA cohort of adult patients with AIDs were retrospectively studied. All underwent molecular testing for periodic fever syndrome gene panels after extensive and negative workups for systemic autoimmune and other related diseases. Patients were divided into Group 1- NLRP3-AID patients with NLRP3 variants (N=15), Group 2- NLRP12-AID with NLRP12 variants (N=14) and Group 3- both NLRP3 and NLRP12 (N=9) variants. Exome sequence data of two large control populations including the ARIC study were used to compare gene variant distribution and frequency.ResultsAll 38 patients were Caucasian with women accounting for 82%. Median age at diagnosis was 41 ± 23 years and the disease duration at diagnosis was 14 ± 13 years. We identified statistically significant differences between the groups, notably that gastrointestinal symptoms as well as evaluations for same were significantly more frequent in patients with NLRP12 variants, and headaches/dizziness were less common among the NLRP12 patients. Livedo reticularis was noted in four patients, exclusively among NLRP12 carriers. Over 50% of patients in Groups 1 and 2 carry low-frequency disease-associated variants, while the remaining carry rare variants. We unprecedently identified digenic variants, i.e., the coexistence of NLRP3 and NLRP12, which were either both low frequency or low frequency/rare. Allele frequencies of all variants identified in our cohort were either absent or significantly lower in the control populations, further strengthening the evidence of susceptibility of these variants to SAID phenotypes.ConclusionOur comparative study shows that both NLRP3-AID and NLRP12-AID share similar clinical phenotypes, yet there are significant differences between them with regard to gastrointestinal and neurological symptoms. A spectrum of high to low genetic variations in both genes can contribute to SAID individually or in combination.

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. [ABSTRACT FROM AUTHOR]

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.

Abstract 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.

Systemic autoinflammatory diseases (SAIDs) are defined by recurrent febrile attacks associated with protean manifestations involving joints, the gastrointestinal tract, skin, and the central nervous system, combined with elevated inflammatory markers, and are caused by a dysregulation of the innate immune system. From a clinical standpoint, the most known SAIDs are familial Mediterranean fever (FMF); cryopyrin-associated periodic syndrome (CAPS); mevalonate kinase deficiency (MKD); and periodic fever, aphthosis, pharyngitis, and adenitis (PFAPA) syndrome. Current guidelines recommend the regular sequential administration of vaccines for all individuals with SAIDs. However, these patients have a much lower vaccination coverage rates in 'real-world' epidemiological studies than the general population. The main purpose of this review was to evaluate the scientific evidence available on both the efficacy and safety of vaccines in patients with SAIDs. From this analysis, neither serious adverse effects nor poorer antibody responses have been observed after vaccination in patients with SAIDs on treatment with biologic agents. More specifically, no new-onset immune-mediated complications have been observed following immunizations. Post-vaccination acute flares were significantly less frequent in FMF patients treated with colchicine alone than in those treated with both colchicine and canakinumab. Conversely, a decreased risk of SARS-CoV-2 infection has been proved for patients with FMF after vaccination with the mRNA-based BNT162b2 vaccine. Canakinumab did not appear to affect the ability to produce antibodies against non-live vaccines in patients with CAPS, especially if administered with a time lag from the vaccination. On the other hand, our analysis has shown that immunization against Streptococcus pneumoniae, specifically with the pneumococcal polysaccharide vaccine, was associated with a higher incidence of adverse reactions in CAPS patients. In addition, disease flares might be elicited by vaccinations in children with MKD, though no adverse events have been noted despite concurrent treatment with either anakinra or canakinumab. PFAPA patients seem to be less responsive to measles, mumps, and rubella-vaccine, but have shown higher antibody response than healthy controls following vaccination against hepatitis A. In consideration of the clinical frailty of both children and adults with SAIDs, all vaccinations remain 'highly' recommended in this category of patients despite the paucity of data available. [ABSTRACT FROM AUTHOR]

Muckle-Wells syndrome (MWS) is an autosomal dominant autoinflammatory disease recognized as the intermediate phenotype of cryopyrin-associated periodic syndrome (CAPS) caused by NLRP3 gene mutation. It often takes a long time before the diagnosis is made because the clinical presentation of MWS is variable. We report a pediatric case who had had persistently elevated serum C-reactive protein (CRP) level since infancy and was diagnosed with MWS by the development of sensorineural hearing loss in school age. The patient had no periodic symptoms of MWS until the development of sensorineural hearing loss. It is important to differentiate MWS in patients with persistent serum CRP elevation, even if no periodic symptoms, including fever, arthralgia, myalgia and rash, are observed. Furthermore, in this patient, lipopolysaccharide (LPS)-induced monocytic cell death occurred, but to a lesser degree than has been reported in patients with chronic infantile neurological cutaneous, and articular syndrome (CINCA). Because CINCA and MWS are phenotypic variants on the same clinical spectrum, this suggests that a further large-scale study is desired to investigate the association between degree of monocytic cell death and disease severity in CAPS patients.

Familial cold autoinflammatory syndrome (FCAS) is the mildest subtype of cryopyrin-associated periodic syndrome (CAPS) and is a rare inherited systemic autoinflammatory disease (SAID). CAPS is the consequence of a rare group of genetic disorders that are mostly reported in European and American populations, but scarcely reported in Chinese populations. NLRP3, NLRP12, PLCG2, and NLRC4 are known pathogenic genes associated with FCAS, and the aim of this study was to identify pathogenic mutations in two intact pedigrees of Chinese FCAS. We performed Sanger sequencing of genomic DNA samples from 25 affected and 32 unaffected members of the two intact pedigrees and analyzed the pathogenic mutations for their conservativeness using multiple sequence alignment tools. In addition, we reviewed previously reported pathogenic genes of FCAS and their pathogenicity classification and summarized the characteristics of different genotypes and phenotypes of FCAS. This study reported two intact FCAS pedigrees with different genotypes and phenotypes, the heterozygous mutation (p.V72M) in NLRP3 in pedigree 1 and the heterozygous mutation (p.R754H) in NLRP12 in pedigree 2. There are no reports targeting p.V72M in NLRP3 in FCAS1, and there are relatively few relevant phenotypic data on the clinical manifestations identified in previous pedigrees. Multiple sequence comparisons of NLRP3 indicate that the p.V72M mutation is highly conserved during evolution. Our study has enriched the understanding of the pathogenesis of FCAS, a rare disease especially in Asian populations. Key Points: •The NLRP3 (p.V72M) variant was first discovered in the Chinese pedigree of FCAS1 •NLRP12 (p.R754H) variants are not conserved in multiple sequence alignments, but they are still co-segregated and expressed in the big Chinese diseased pedigree [ABSTRACT FROM AUTHOR]

Background: Cryopyrin‐associated periodic syndrome (CAPS) is an autoinflammatory disorder with a spectrum ranging from the milder familial cold auto‐inflammatory syndrome (FCAS) phenotype to the more severe Muckle–Wells Syndrome. Although headaches are the most common neurological symptoms, neuroinflammatory diseases such as multiple sclerosis (MS) have only been reported in the more severe phenotypes. Case Presentation: We describe a 43‐year‐old male diagnosed with relapse‐remitting MS who developed cold‐induced arthralgias and urticaria. He initially presented with facial numbness and arthralgias in his late teenage years, and brain magnetic resonance imaging (MRI) demonstrated multiple lesions with periventricular white matter extension. Oligoclonal bands were detected in the cerebrospinal fluid (CSF). Symptoms gradually improved, and a decade later he presented with numbness at upper limbs and tongue. Brain and spine MRI showed new lesions, but CSF was unremarkable. He was started on interferon β‐1a with symptomatic improvement until another flare around 13 years later. Treatment was changed to dimethyl fumarate. During this hospitalization, urticaria was problematic and particularly associated with cold temperatures. This raised suspicion for possible CAPS and subsequently confirmed with an A439V mutation in the NLRP3 gene, consistent with FCAS. Anakinra was started but was not tolerated because of localized reactions despite desensitization. His serum amyloid A was mildly elevated at 9 mg/L (reference range 0–6). He remains stable from a neurological perspective, including imaging, and continues dimethyl fumarate. Conclusions: To date, FCAS and possible association with MS has not been described. The case raises challenges in the diagnosis of concurrent disease processes. It also highlights that neurological sequelae should be considered in all spectrums of CAPS, and distinctions with MS should be made where possible. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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.

Abstract is missing (Short communication)

Systemic autoinflammatory diseases (SAIDs) are defined by recurrent febrile attacks associated with protean manifestations involving joints, the gastrointestinal tract, skin, and the central nervous system, combined with elevated inflammatory markers, and are caused by a dysregulation of the innate immune system. From a clinical standpoint, the most known SAIDs are familial Mediterranean fever (FMF); cryopyrin-associated periodic syndrome (CAPS); mevalonate kinase deficiency (MKD); and periodic fever, aphthosis, pharyngitis, and adenitis (PFAPA) syndrome. Current guidelines recommend the regular sequential administration of vaccines for all individuals with SAIDs. However, these patients have a much lower vaccination coverage rates in ‘real-world’ epidemiological studies than the general population. The main purpose of this review was to evaluate the scientific evidence available on both the efficacy and safety of vaccines in patients with SAIDs. From this analysis, neither serious adverse effects nor poorer antibody responses have been observed after vaccination in patients with SAIDs on treatment with biologic agents. More specifically, no new-onset immune-mediated complications have been observed following immunizations. Post-vaccination acute flares were significantly less frequent in FMF patients treated with colchicine alone than in those treated with both colchicine and canakinumab. Conversely, a decreased risk of SARS-CoV-2 infection has been proved for patients with FMF after vaccination with the mRNA-based BNT162b2 vaccine. Canakinumab did not appear to affect the ability to produce antibodies against non-live vaccines in patients with CAPS, especially if administered with a time lag from the vaccination. On the other hand, our analysis has shown that immunization against Streptococcus pneumoniae, specifically with the pneumococcal polysaccharide vaccine, was associated with a higher incidence of adverse reactions in CAPS patients. In addition, disease flares might be elicited by vaccinations in children with MKD, though no adverse events have been noted despite concurrent treatment with either anakinra or canakinumab. PFAPA patients seem to be less responsive to measles, mumps, and rubella-vaccine, but have shown higher antibody response than healthy controls following vaccination against hepatitis A. In consideration of the clinical frailty of both children and adults with SAIDs, all vaccinations remain ‘highly’ recommended in this category of patients despite the paucity of data available.

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., (© Japan College of Rheumatology 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: Cryopyrin-Associated Periodic Syndromes (CAPS) encompasses a spectrum of Interleukin-1 (IL-1) driven systemic diseases with dramatic individual and societal burden. The study aimed to identify parameters and instruments to refine real-life Treat-to-Target (T2T) strategies and control CAPS disease activity., Methods: A single-centre, longitudinal study of consecutive children and adults diagnosed with CAPS and treated with anti-IL-1 therapy was performed. Demographics, clinical phenotype and NLRP3 gene variants in addition to serial inflammatory markers and Physician and Patient/Parent Global Assessments (PGA/PPGA) were captured. Effectiveness of anti-IL-1 T2T strategies and factors associated with therapy escalation were determined., Results: A total of 54 CAPS patients with 759 follow-up visits were included; 31/54 (57%) were children; the median follow-up was 108 months (12-620). The moderate CAPS phenotype was present in 89%; overall 59% had pathogenic/likely pathogenic NLRP3 variants. Therapy adjustments were documented in 50/759 visits including 35 therapy escalations and 15 reductions; 74% of the therapy escalation visits were for children. At time of visit, 63% showed moderate, 37% severe clinical disease activity. Inflammatory markers remained largely normal. Significant improvement was observed in both PGA/PPGA throughout the study (p< 0.01). At the last follow-up, 96% of patients achieved remission., Conclusion: Guidance for refining real-life T2T strategies in CAPS cohorts can be drawn from serial assessments of PGA and PPGA reliably reflecting changes in disease activity. Individual parameters including age and NLRP3 gene variants are important predictors, while the sensitivity of inflammatory markers is limited due to the confounding anti-IL-1 therapy., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

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., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Background. Cryopyrin-associated periodic syndromes is a group of rare congenital autoinflammatory diseases such as familial cold autoinflammatory syndrome, Muckle-Wells syndrome and chronic infantile neurological cutaneous articular syndrome. These syndromes are considered as clinical variants of one disease with different intensity of clinical features and severity of pathologic process. The onset of these syndromes is usually on the first year of life, and they start with fever, urticarial rash, various variants of joint diseases (from arthralgia to residual and persistent arthritis) and nervous system disturbances. There are only single case reports of cryopyrin-associated periodic syndromes in Russia.Clinical Case Description. The disease onset was at the age of 1 year 8 months with fever and rash as well as generalized joint syndrome. Autoinflammatory syndrome was suspected due to to results of blood tests, MRI, molecular genetic testing. Exons 2, 3 and 4 of TNFRSF1A gene and exon 4 of NLRP3 gene with nearby introns were studied with the method of direct automated sequencing. The c.943A>G variant in heterozygous state in NLRP3 gene was revealed. The child was treated with IL-1 beta inhibitor (canakinumab) with positive effect.Conclusion. Diagnostics of cryopyrin-associated periodic syndrome in children is the serious challenge. Timely decision with help of molecular genetic methods is crucial for successful target therapy.

Objectives Gradually progressive sensorineural hearing loss (SNHL) is a prevalent sensory defect. It is generally untreatable, making rehabilitation by hearing aid or cochlear implantation the only option. However, SNHL as one of the symptoms of the hereditary autoinflammatory systemic disease cryopyrin-associated periodic syndrome, or as the only symptom of the cochlea-specific form (DFNA34), was suggested to respond to IL-1 antagonist (anakinra) therapy, which ameliorates NLRP3 variants-induced over-secretion of IL-1β. We analysed genotypic and phenotypic spectrum of cryopyrin-associated periodic syndrome or DFNA34, specifically focusing on the responsiveness of SNHL to anakinra. Methods Seventeen families diagnosed with either cryopyrin-associated periodic syndrome or DFNA34 were recruited. Genotyping and phenotyping including audiogram, MRI findings, and in vitro IL-1β assay were performed. Results Our cohort had an etiologic homogeneity of 94.1% to NLRP3 variants and a high de novo occurrence (84.6%). We identified the second DNFA34 pedigree worldwide with a novel NLRP3 variant supported by in vitro analysis. Significant improvement of hearing status against the natural course, showing response to anakinra, was identified in three probands, one of whom used to have severe SNHL. Hearing threshold worse than 60 dB at the start of anakinra and cochlear enhancement on brain MRI seemed to be related with poor audiologic prognosis and responsiveness to anakinra therapy despite stabilized systemic symptoms and inflammatory markers. Conclusion We propose a constellation of biomarkers comprising NLRP3 genotypes, hearing status at diagnosis, and cochlear radiological findings as prognostic factors of hearing status after anakinra treatment and possibly as sensitive parameters for treatment dosage adjustment. [ABSTRACT FROM AUTHOR]

Objectives: The major role of interleukin (IL)-1 in the pathogenesis of hereditary recurrent fever syndromes favored the employment of targeted therapies modulating IL-1 signaling. However the best use of IL1 inhibitors in terms of dosage is difficult to define at present.Methods: In order to better understand the use of IL1 inhibitors in a real-life setting, our study assessed the dosage regimens of French patients with one of the four main hereditary recurrent fever syndromes (Familial Mediterranean Fever (FMF), TNF receptor associated periodic syndrome (TRAPS), cryopyrin associated periodic fever (CAPS) and mevalonate kinase deficiency). The patients were retrieved retrospectively from the JIR cohort, an international platform gathering data of patients with pediatric inflammatory diseases.Results: Forty five patients of the JIR cohort with a hereditary recurrent fever syndrome had received at least once an IL1 inhibitor (anakinra or canakinumab). Of these, 43% received a lower dosage than the one suggested in the product recommendations, regardless of the type of the IL1 inhibitor. Especially patients with FMF and TRAPS seemed to need lower treatment regimens; in our cohort none of the FMF or TRAPS patients received an intensified dose of IL-inhibitor. On-demand treatment with a short half-life IL-1 inhibitor has also been used successfully for some patients with one of these two conditions The standard dose was given to 42% of the patients; whereas an intensified dose of IL-1 inhibitors was given to 15% of the patients (44% of CAPS patients and 17% of mevalonate kinase deficiency patients). In our cohort each individual patient’s need for treatment seemed highly variable, ranging from on demand treatment regimens to intensified dosage maintenance therapies depending on the activity and the severity of the underlying disease.Conclusion: IL-1 inhibitors are a good treatment option for patients with a hereditary recurrent fever syndrome, but the individual need of the dosage of IL-1 inhibitors to control the disease effectively seems highly variable. Severity, activity but also the type of the underlying disease, belong to the parameters underpinning the treat-to-target strategy implemented in an everyday life practice.

Cyropyrin-associated periodic syndromes (CAPS) are clinically distinct syndromes that encompass a phenotypic spectrum yet are caused by alterations in the same gene, NLRP3. Many CAPS cases and other NLRP3-autoinflammatory diseases (NLRP3-AIDs) are directly attributed to protein-coding alterations in NLRP3 and the subsequent dysregulation of the NLRP3 inflammasome leading to IL-1β-mediated inflammatory states. Here, we used bioinformatics tools, computational modeling, and computational assessments to explore the proteomic consequences of NLRP3 mutations, which potentially drive NLRP3 inflammasome dysregulation. We analyzed 177 mutations derived from familial cold autoinflammatory syndrome (FCAS), Muckle-Wells Syndrome (MWS), and the non-hereditary chronic infantile neurologic cutaneous and articular syndrome, also known as neonatal-onset multisystem inflammatory disease (CINCA/NOMID), as well as other NLRP3-AIDs. We found an inverse relationship between clinical severity and the severity of predicted structure changes resulting from mutations in NLRP3. Bioinformatics tools and computational modeling revealed that NLRP3 mutations that are predicted to be structurally severely-disruptive localize around the ATP binding pocket and that specific proteo-structural changes to the ATP binding pocket lead to enhanced ATP binding affinity by altering hydrogen-bond and charge interactions. Furthermore, we demonstrated that NLRP3 mutations that are predicted to be structurally mildly- or moderately-disruptive affect protein-protein interactions, such as NLRP3-ASC binding and NLRP3-NLRP3 multimerization, enhancing inflammasome formation and complex stability. Taken together, we provide evidence that proteo-structural mechanisms can explain multiple mechanisms of inflammasome activation in NLRP3-AID.

Cryopyrin-associated periodic syndrome (CAPS) is a rare hereditary inflammatory disorder encompassing a continuum of three phenotypes: familial cold autoinflammatory syndrome, Muckle-Wells syndrome, and neonatal-onset multisystem inflammatory disease. Distinguishing features include cutaneous, neurological, ophthalmologic, and rheumatologic manifestations. CAPS results from a gain-of-function mutation of the NLRP3 gene coding for cryopyrin, which forms intracellular protein complexes known as inflammasomes. Defects of the inflammasomes lead to overproduction of interleukin-1, resulting in inflammatory symptoms seen in CAPS. Diagnosis is often delayed and requires a thorough review of clinical symptoms. Remarkable advances in our understanding of the genetics and the molecular pathway that is responsible for the clinical phenotype of CAPS has led to the development of effective treatments. It also has become clear that the NLRP3 inflammasome plays a critical role in innate immune defense and therefore has wider implications for other inflammatory disease states.

Abstract Background Cryopyrin-associated periodic syndrome (CAPS) is a rare disease. Knowledge on the quality of life (QoL) and the disease’s societal impact is limited. Canakinumab is used in increasing frequency for the treatment of CAPS. Methods Observational study in Dutch CAPS patients. Patients completed questionnaires regarding treatment with canakinumab at baseline and retrospectively. Quality of life was assessed using the EQ-5D-5L in adults and CHQ-PF50 in children. Impact on work and school was assessed. Caregivers' quality of life was assessed using the CarerQol. Results Mean quality of life scores during treatment with canakinumab were 0.769 (EQ-5D-5L), 51.1 (CHQ-P) and 57–1 (CHQ-M). Most patients experienced problems on the pain/discomfort dimension. Higher disease activity and the presence of complications negatively influenced QoL. Half of the patients with a paid job reported absenteeism from work due to CAPS, for an average of 8.7 days in a 4-week period. All schoolgoing patients (N = 5) reported absence from school due to CAPS, for an average of 2.9 days. Caregivers reported gaining a lot fulfillment from providing care for their family members. Conclusion QoL during treatment is lower than in the general Dutch population. CAPS leads to productivity loss and absenteeism from school, and impacts the quality of life in informal caregivers.

Cyropyrin-associated periodic syndromes (CAPS) are clinically distinct syndromes that encompass a phenotypic spectrum yet are caused by alterations in the same gene, NLRP3. Many CAPS cases and other NLRP3 -autoinflammatory diseases (NLRP3 -AIDs) are directly attributed to protein-coding alterations in NLRP3 and the subsequent dysregulation of the NLRP3 inflammasome leading to IL-1β-mediated inflammatory states. Here, we used bioinformatics tools, computational modeling, and computational assessments to explore the proteomic consequences of NLRP3 mutations, which potentially drive NLRP3 inflammasome dysregulation. We analyzed 177 mutations derived from familial cold autoinflammatory syndrome (FCAS), Muckle-Wells Syndrome (MWS), and the non-hereditary chronic infantile neurologic cutaneous and articular syndrome, also known as neonatal-onset multisystem inflammatory disease (CINCA/NOMID), as well as other NLRP3 -AIDs. We found an inverse relationship between clinical severity and the severity of predicted structure changes resulting from mutations in NLRP3. Bioinformatics tools and computational modeling revealed that NLRP3 mutations that are predicted to be structurally severely-disruptive localize around the ATP binding pocket and that specific proteo-structural changes to the ATP binding pocket lead to enhanced ATP binding affinity by altering hydrogen-bond and charge interactions. Furthermore, we demonstrated that NLRP3 mutations that are predicted to be structurally mildly- or moderately-disruptive affect protein-protein interactions, such as NLRP3-ASC binding and NLRP3-NLRP3 multimerization, enhancing inflammasome formation and complex stability. Taken together, we provide evidence that proteo-structural mechanisms can explain multiple mechanisms of inflammasome activation in NLRP3- AID. [ABSTRACT FROM AUTHOR]

Objective The new classification criteria for the hereditary recurrent fever (HRF) syndrome [cryopyrin-associated periodic syndrome (CAPS), TNF-α receptor-associated periodic syndrome (TRAPS), FMF and mevalonate kinase deficiency] have been published recently. These criteria define two core sets of criteria for each HRF: mixed criteria, including genetic and clinical variables, and clinical criteria, relying on clinical variables only. Our aim was to validate the criteria for HRF in an independent cohort, the JIR Cohort database, an international repository of systemic inflammatory diseases. Methods We enrolled patients with HRF, periodic fever, adenitis, pharyngitis and aphthous stomatitis syndrome (PFAPA) and syndrome of undefined recurrent fever (SURF). A score ranging from zero to two was attributed to their respective genotypes: zero (no mutation), one (non-confirmatory genotype) or two (confirmatory genotype). The criteria were applied to all patients based on genotype scoring. The treating physician's diagnosis served as the gold standard for the determination of specificity. Results We included 455 patients. The classification criteria showed excellent specificity for CAPS and TRAPS (98% specificity each), fair specificity for FMF (88%), but poor specificity for mevalonate kinase deficiency (58%). Sub-analysis showed excellent accuracy of the mixed criteria for all four HRFs. Misclassification was mainly attributable to clinical criteria sets, with false-positive patients in all four HRF clinical criteria sets. Conclusion This study represents the final validation step of the HRF classification criteria as recommended by the ACR. Genetic data appear to be necessary to classify patients with HRF correctly. [ABSTRACT FROM AUTHOR]

Cryopyrin-associated periodic syndrome is a hereditary inflammatory disorder encompassing a wide spectrum of clinical phenotypes. This disorder has been associated with mutation of the NLRP3 gene coding for cryopyrin, which leads to overproduction of interleukin-1. The condition causes relapsing bouts of inflammation involving multiple organ systems, including the central nervous system, and, if untreated, can lead to long-term debilitating effects. A literature review revealed only a few brief descriptions of magnetic resonance imaging findings in cryopyrin-associated periodic syndrome patients. We describe serial magnetic resonance imaging findings in an 11-year-old female with clinically diagnosed cryopyrin-associated periodic syndrome who presented with intermittent headaches, progressive sensorineural hearing loss, fevers, and abdominal pain. The magnetic resonance imaging showed progressively worsening low T2 signal in the cochlea, cochlear enhancement, and leptomeningeal enhancement. We also describe some previously unreported findings in this syndrome, including cranial nerve and cauda equina enhancement. [ABSTRACT FROM AUTHOR]

Cryopyrin-associated periodic syndrome (CAPS) is a group of rare hereditary autoinflammatory diseases characterised by recurrent flares of mild to severe systemic inflammation and fever. CAPS is the umbrella term for a spectrum of individual conditions, namely familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS) and neonatal-onset multisystem inflammatory disease (NOMID), also known as chronic infantile neurologic, cutaneous and articular (CINCA) syndrome. The flare symptoms include fever, fatigue, rashes, headaches, arthralgia and myalgia that can last for a few hours or for several days. These symptoms are debilitating, contributing to poor quality of life for patients if left untreated. Serious life-changing complications such as hearing loss, blindness and AA amyloidosis resulting in kidney failure can occur. Until recently, treatment of the disease was symptomatic using non-steroidal anti-inflammatory and immunosuppressant drugs with limited success. In contrast, biological treatments targeting interleukin 1 (IL-1) have proved remarkably effective, often associated with complete and sustained disease remission, vastly improved quality of life and avoidance of serious long-term complications. [ABSTRACT FROM AUTHOR]

Abstract Infant-onset bilateral sensorineural hearing loss is a key presenting symptom of the autoinflammatory cryopyrin-associated periodic syndrome. Other symptoms include periodic fever, cold-induced urticaria-like rash, chronic aseptic meningitis, polyarticular arthralgias, and renal AA amyloidosis. Early recognition and treatment with interleukin-1 blockade are critical for preventing disabling or fatal complications. We describe a patient with severe cryopyrin-associated periodic syndrome who presented at age 18 months with macrocephaly and moderate sensorineural hearing loss, later developing systemic sequelae. The pathogenic nature of the de novo NLRP3 gene variant identified was supported by a markedly elevated serum amyloid A level and sustained clinical response to anti-IL-1 therapy. [ABSTRACT FROM AUTHOR]

Neurologic complications of chronic infantile neurologic, cutaneous and articular syndrome (CINCA) are well-known, whereas there are scarce data regarding neurologic features of milder cryopyrin-associated periodic syndrome (CAPS) phenotypes. We aimed to review the neurologic features in detail and summarize the other CAPS-related manifestations in 12 children. All children with CAPS that have been followed-up from pediatric rheumatology outpatient clinic, were enrolled to the study. In addition to the neurologic examination, magnetic resonance imaging (MRI) of brain, electroencephalography, eye examination, hearing test and intellectual assessment were done. Demographic, clinical features, genetic analysis and laboratory tests were noted from patient records and hospital database. The median age of the subjects was 7 years (range 2–19 years), with a female-to-male ratio 2/1. The phenotype was consistent with familial cold autoinflammatory syndrome in 7 patients, Muckle–Wells syndrome in 3 patients and chronic infantile neurologic, cutaneous and articular syndrome in 2 patients. Most frequently noted neurologic clinical manifestation during the entire disease course was headache (n = 4/12) followed by seizures (n = 3/12), papilledema (n = 3/12), intellectual disability (n = 2/12), aseptic meningitis (n = 2/12), hearing loss (n = 2/12) and optic atrophy (n = 1/12). MRI of the brain revealed abnormal lesions in two patients. Uveitis or conjunctivitis were seen in two children. Overall, neurological involvement was detected in 6/12 of our cohort, of which half (n = 3) was in severe form. Half of the children with CAPS exhibited neurologic manifestations with varying degrees of severity. Increased understanding and awareness of this rare but treatable syndrome among neurologists is essential. If remains untreated and unrecognized, this autoinflammatory syndrome could lead to significant morbidity and mortality. Besides complete resolution of systemic symptoms, anti-interleukin-1 treatment may also prevent progression of neurologic findings when initiated in the early stage of the disease. • CAPS is an autoinflammatory syndrome with frequent neurological manifestations. • Management of this multisystemic disease requires a team approach. • Delayed diagnosis leads to significant morbidity and mortality. • Increased awareness of this rare but treatable IL1-associated disease is essential. [ABSTRACT FROM AUTHOR]

Cryopyrin-Associated Periodic Syndrome (CAPS) refers to a group of autoinflammatory diseases and is caused by autosomal dominant mutations of the NLRP3 gene coding. Relapsing fever, rash, laboratory changes and inflammatory lesions of various organs are typical manifestations of CAPS. Inhibitors of interleukin 1, including canakinumab, are modern means of pathogenetic therapy of patients with CAPS. The article presents the treatment results in 5 pediatric patients with CAPS. Application of canakinumab led to the relief of all major symptoms (fever, inflammatory changes in the blood lymphoproliferation, signs of organ damage), and no relevant side effects was detected.

Muckle-Wells syndrome (MWS) is an autoinflammatory disease belonging to a group of cryopyrin-associated periodic syndromes (CAPS). It is considered to be one of the intermediately severe conditions among CAPSs and to be intermediate between the severest syndrome – Chronic I nfantile Onset Neurologic Cutneous Articular/Neonatal Onset Multisystem Inflammatory Disease (CINCA/NOMID) and the mildest syndrome–Familial Cold Autoinflammatory Syndrome (FCAS). MWS, like all cryopyrinopathies, is caused by a mutation in the NLRP3 (CIAS1) gene; it shows an autosomal inheritance pattern. There are reports on familial MWS cases in the foreign literature; such examples are sporadic in Russia. The given clinical observation clearly demonstrates a genetically verified familial case of MWS in a mother and her daughter in a Russian population and shows how long (occasionally during tens of years or more) the complete complex of the disease may be formed. The results of treatment with the interleukin-1 inhibitor canakinumab in both patients are also given. The high good tolerability and high efficacy of the drug against the clinical manifestations of MWS and acute-phase markers are shown.

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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Shu, Zhang, Han, Li, Piao, Sun, Ma, Mo, Sun, Chan, Yang, Lau and Mao.)