CIAS1 Mutations Research Articles

Periodic Syndrome Associated to Cryopyrin: About 10 Cases

NLRP3 gene responsible for an uncontrolled activation of the innate immunity. Objective is to study epidemiological, clinical, genetic, therapeutic and evolutionary characteristics of CAPS. Material and methods: It is a retrospective analysis over 20 years (2000 to 2020) of 10 cases of CAPS, followed by the P-IV service and the pediatric rheumatology consultation at the Rabat children’s hospital. Results: The mean age at diagnosis was 3 years and 7 months with a masculine predominance of 70%. 06 patients were born to consanguineous parents (first degree). Clinical signs were a recurrent fever in 90%, osteo-articular involvement in 90% with patellar hypertrophy in 04 patients, skin signs were found in all patients 100%, neurological involvement in 70%, sensorial disabilities in 10%, dysmorphic facies in 80%, and failure to thrive in 80%. None of our patients had renal amyloidosis. An inflammatory syndrome was present in all patients 100%. Radiography of joints showed a modeling disorder of the femoral metaphysis in 02 patients, osteoporosis in 02 others, epiphyseal remodeling, and irregular ossification of patella in 01 patient. The genetic studies could only be done to one patient, and it revealed a CIAS1 mutation. NSAIDs and corticosteroids were prescribed to 07 patients with good evolution, and 02 patients received biotherapy, after NSAIDs and steroids treatment failure, with clear improvement. Conclusion: CAPS are rare diseases, and they are largely unknown. Diagnostic and therapeutic management should be early and prompt to avoid irreversible complications and improve the quality and expectancy of life.

The evaluation of gene polymorphisms associated with autoinflammatory syndrome in patients with palindromic rheumatism complicated by intermittent hydrarthrosis.

Palindromic rheumatism (PR) is a type of acute arthritis or periarthritis characterized by recurrence, paroxysmal, or intermittent disease attacks and occasionally progresses to other types of rheumatic disease. PR patients who are anti-citrullinated protein antibodies (ACPA)-negative have a high prevalence of MEFV gene polymorphisms, and intermittent hydrarthrosis (IH) is also associated with MEFV polymorphisms. The purpose of this study was to evaluate the clinical characteristics of and autoinflammatory syndrome-associated gene polymorphisms in patients with PR and IH and to identify predictive factors for developing other rheumatic diseases. Six PR patients (four females; median age at disease onset, 20.0years; median age at evaluation, 47.0years) were retrospectively evaluated for clinical features and polymorphisms in genes responsible for autoinflammatory diseases. All six patients fulfilled the diagnostic criteria for PR and showed clinical feature of IH. Two presented with recurrent fever. All six patients were negative for rheumatoid factor and ACPA and had normal articular X-ray findings. Among the six patients, MEFV gene polymorphisms known to cause FMF were identified in four, CIAS1 mutation was observed in one, and TNFRSFIA mutation was observed in one. Colchicine was effective in three patients with MEFV polymorphisms. The other five patients continued to experience PR, although three patients achieved remission with medication. PR presenting with IH might be associated with gene polymorphisms responsible for autoinflammatory diseases; colchicine appears to be effective in these patients.Key Point• Palindromic rheumatism with intermittent hydrarthrosis might be associated with gene polymorphisms responsible for autoinflammatory diseases.

Somatic mosaicism of CIAS1/NLRP3 gene in two patients with chronic infantile neurologic, cutaneous, articular syndrome

CINCA syndrome (chronic, infantile, neurological , cutaneous, articular syndrome) also known as neonatal-onset multisystem inflammatory disease (NOMID) represents the most severe form of cryopyrin-associated periodic syndrome ( CAPS). This condition was found to be associated with missense mutations in the CIAS1/NALP3/PYPAF gene, which encodes cryopyrin. Cryopyrin is a member of the cytoplasmatic protein family CATERPILLER, which is involved in inflammasome molecular platform assembly, leading to inflammatory immune response and apoptosis regulation. It has been hypothesized that mutant cryopirin spontaneously oligomerizes and induces the inflammasome activation with elevated IL-1β production and autoinflammatory phenotype. Causative CIAS1 mutations have been detected in only half of the patients with CINCA and the genetic cause of the disease in patients who tested negative remains unclear.

3,4-Methylenedioxy-β-nitrostyrene Inhibits NLRP3 Inflammasome Activation by Blocking Assembly of the Inflammasome

The NLRP3 inflammasome is a critical component of the innate immune system. NLRP3 activation is induced by diverse stimuli associated with bacterial infection or tissue damage, but its inappropriate activation is involved in the pathogenesis of inherited and acquired inflammatory diseases. However, the mechanism by which NLRP3 is activated remains poorly understood. In this study, we explored the role of kinases in NLRP3 inflammasome activation by screening a kinase inhibitor library and identified 3,4-methylenedioxy-β-nitrostyrene (MNS) as an inhibitor for NLRP3 inflammasome activation. Notably, MNS did not affect the activation of the NLRC4 or AIM2 (absent in melanoma 2) inflammasome. Mechanistically, MNS specifically prevented NLRP3-mediated ASC speck formation and oligomerization without blocking potassium efflux induced by NLRP3 agonists. Surprisingly, Syk kinase, the reported target of MNS, did not mediate the inhibitory activity of MNS on NLRP3 inflammasome activation. We also found that the nitrovinyl group of MNS is essential for the inhibitory activity of MNS. Immunoprecipitation, mass spectrometry, and mutation studies suggest that both the nucleotide binding oligomerization domain and the leucine-rich repeat domain of NLRP3 were the intracellular targets of MNS. Administration of MNS also inhibited NLRP3 ATPase activity in vitro, suggesting that MNS blocks the NLRP3 inflammasome by directly targeting NLRP3 or NLRP3-associated complexes. These studies identified a novel chemical probe for studying the molecular mechanism of NLRP3 inflammasome activation which may advance the development of novel strategies to treat diseases associated with abnormal activation of NLRP3 inflammasome.

Homeostatic Tissue Responses in Skin Biopsies from NOMID Patients with Constitutive Overproduction of IL-1β

The autoinflammatory disorder, Neonatal-onset Multisystem Inflammatory Disease (NOMID) is the most severe phenotype of disorders caused by mutations in CIAS1 that result in increased production and secretion of active IL-1β. NOMID patients present with systemic and organ-specific inflammation of the skin, central nervous system and bone, and respond dramatically to treatment with IL-1 blocking agents. We compared the cellular infiltrates and transcriptome of skin biopsies from patients with NOMID (n = 14) before treatment (lesional (LS) and non-lesional (pre-NL) skin) and after treatment (post-NL) with the IL-1 blocker anakinra (recombinant IL-1 receptor antagonist, Kineret®, Swedish Orphan Biovitrum AB, SOBI), to normal skin (n = 5) to assess tissue responses in the context of untreated and treated disease. Abundant neutrophils distinguish LS skin from pre-NL and post-NL skin. CD11c+ dermal dendritic cells and CD163+ macrophages expressed activated caspase-1 and are a likely source of cutaneous IL-1 production. Treatment with anakinra led to the disappearance of neutrophils, but CD3+ T cells and HLA-DR+ cells remained elevated. Among the upregulated genes IL-6, IL-8, TNF, IL-17A, CCL20, and the neutrophil defensins DEFA1 and DEFA3 were differentially regulated in LS tissues (compared to normal skin). Important significantly downregulated pathways in LS skin included IL-1R/TLR signaling, type I and II cytokine receptor signaling, mitochondrial dysfunction, and antigen presentation. The differential expression and regulation of microRNAs and pathways involved in post-transcriptional modification were suggestive of epigenetic modification in the chronically inflamed tissue. Overall, the dysregulated genes and pathways suggest extensive “adaptive” mechanisms to control inflammation and maintain tissue homeostasis, likely triggered by chronic IL-1 release in the skin of patients with NOMID.

IL-1 blockade as a novel approach to treatment of hyperzincemia and hypercalprotectinemia, a possible new autoinflammatory syndrome

Methods We describe a patient initially evaluated at 10 months of age for gross developmental delay, failure to thrive, splenomegaly, and microcytic anemia. Physical exam was significant for weight <3rd percentile, splenomegaly (down 5cm), and head lag. Initial laboratories revealed microcytic anemia (hemoglobin 8.7 g/dL); elevated platelets 499 K/uL, C-reactive protein 23.2 mg/dL (<0.2) and erythrocyte sedimentation rate 120 mm/h (0-10). Radiographs showed Erlenmeyer flask deformities of the femurs. Workup for lysosomal storage disorders, oncologic processes, and infections were negative. Genetic testing of known mutations in FAS, CIAS1, ELA2, LPIN2, MVK, PSTPIP1, and TNFRSF1A were negative. Immunoglobulins were elevated with normal T and B cells. On further workup for failure to thrive, a plasma zinc level was found elevated at 532 mcg/dL (60-120). Due to his persistently inflamed state, there was concern for hyperzincemia related to hypercalprotectinemia. Calprotectin level, measured by enzyme-linked immunosorbent assay, was elevated: 428,300 ng/mL (<420). On the basis of these findings the diagnosis of hyperzincemia associated with hypercalprotectinemia was made (OMIM 194470). Additionally, the patient’s workup has revealed the following mutations with unknown clinical significance: a heterozygous variant in the MEFV gene (T577A), a hemizygous duplication of exons 61-79 of the dystrophin gene (CPK normal), and a maternally inherited microduplication at Xp21.2. Colchicine was started due to the MEFV gene mutation with little to no improvement. Based on calprotectin’s role in inflammation, and possible link to IL-1, anakinra was initiated.

Effect of anakinra on arthropathy in CINCA/NOMID syndrome

CINCA/NOMID is an autoinflammatory disorder characterized by the triad of neonatal onset of cutaneous symptoms, chronic meningitis, and recurrent fever and it presents with distinctive osteoarthropathy, synovitis mainly of the large joints and overgrowth of epimetaphyseal cartilage, particularly of the long bones. The cartilage overgrowth eventually causes osseous overgrowth and deformity that persists beyond skeletal maturity and leads to limb length discrepancy, joint contracture, and early degenerative arthropathy. Autoinflammation in CAPS/NOMID has been proven to derive from excessive release of interleukin-1 (IL-1). It has been well documented that the IL-1 receptor antagonist anakinra (Kineret(R)) helps mitigate systemic inflammation in the disorder. However, a general consensus has not been reached on its beneficial effect on osteoarthropathy. The case of a girl with CINCA/NOMID syndrome who showed dramatic improvement of osteoarthropathy after anakinra treatment is reported. A 4-year-old girl suffered at the age of 10 months from a generalized urticarial skin lesion with recurrent episodes of fever and growth disorder. Blood examination revealed persistent massive neutrophilia, anemia and intense acute phase response. She manifested knee joint swelling with limited ROM when she was 20 months old and was diagnosed as being CINCA/NOMID based on characteristic findings of radiograph despite negative CIAS1 mutation. Radiological examination demonstrated metaphyseal fraying and cupping and widening of the growth plate in the distal femur. MR imaging showed mottled gadolinium enhancement at the chondrosseous junction. Neither significant joint effusion nor synovitis was identified. At 2 years and 7 months of age, anakinra, 2 mg/kg/day given by regular daily subcutaneous injections, was started. A few days after the initiation of the treatment, her clinical symptoms and laboratory findings of active inflammation were promptly alleviated. She was not able to walk unaided prior to the treatment, but she walked independently 1 month after the treatment. Follow-up radiographs and MR imaging showed that growth plate widening and gadolinium enhancement at the chondrosseous junction were less conspicuous. Furthermore, longitudinal growth of the femur and tibia was identified during 20 months of observation.

Long‐term efficacy of the interleukin‐1 receptor antagonist anakinra in ten patients with neonatal‐onset multisystem inflammatory disease/chronic infantile neurologic, cutaneous, articular syndrome

Cryopyrin-associated periodic syndromes (CAPS) are a group of rare autoinflammatory diseases. Neonatal-onset multisystem inflammatory disease (NOMID)/chronic infantile neurologic, cutaneous, articular syndrome (CINCA syndrome) is the most severe phenotype, with fever, rash, articular manifestations, and neurologic and neurosensory involvement. CAPS are caused by mutations in CIAS1, the gene encoding NLRP3, which plays a critical role in interleukin-1 (IL-1) processing. Anakinra, an IL-1 receptor antagonist, has been shown to be an effective treatment; however, data on long-term efficacy and safety have been sparse. This study was undertaken to assess the long-term efficacy and safety of anakinra treatment in patients with NOMID/CINCA syndrome. We retrospectively analyzed the medical records of NOMID/CINCA syndrome patients referred to 2 centers, who had started anakinra treatment before June 2007. There were 10 patients with NOMID/CINCA syndrome who had been treated with anakinra. The patients' ages at the time anakinra treatment was initiated ranged from 3 months to 20 years. They had been followed up for 26-42 months. Sustained efficacy in the treatment of systemic inflammation and, in some cases, neurologic involvement and growth parameters, was achieved. The dosage of anakinra required for efficacy ranged from 1 to 3 mg/kg/day in the 8 oldest patients and from 6 to 10 mg/kg/day in the 2 youngest. Residual central nervous system inflammation and deafness persisted in some patients, especially if there had been a delay in diagnosis and treatment. Secondary amyloidosis persisted in cases in which it was present at treatment initiation, but no new lesions developed. No effect on overgrowth arthropathy was observed. Adverse events consisted of mild injection-site reactions. The present results indicate that anakinra treatment is effective over the long term in NOMID/CINCA syndrome. However, treatment has to be initiated before irreversible lesions develop, and, particularly in very young patients, dosage adjustment is required.

Une cause rare d’œdème papillaire : le CINCA syndrome. Les cas de jumeaux homozygotes

CINCA syndrome is an autoinflammatory disease in childhood characterized by multisystemic manifestations: cutaneous, articular, and neurological including sensory organs. We report the case of homozygous twins affected by CINCA syndrome. The diagnosis was evoked on the basis of multiple systemic symptoms (multiple episodes of fever of unknown origin, mental retardation, short stature, meningitis, hearing loss, bilateral papilledema) and confirmed by the presence of a CIAS1 mutation on genetic analysis. After few months of treatment by anakinra (an interleukin-1 receptor antagonist) the children began to grow again and we noted regression of the biological inflammatory syndrome.

Infantile Onset Panniculitis with Uveitis and Systemic Granulomatosis: immunohistochemical findings

Infantile-Onset Panniculitis with Systemic Granulomatosis is a recently described clinicopathologic entity, considered part of the spectrum of pediatric granulomatous inflammatory diseases. Through the International Registry of Pediatric Granulomatous Arthritis (PGA), we now identified 5 children with this disorder, all manifesting from very young age panniculitis, fever, hepatosplenomegaly, arthritis, uveitis and acute phase response. Underlying infections, immune deficiency and autoimmune disease, were excluded. No CARD15 or CIAS1 mutations were found. Histologically, the subcutaneous nodules showed a non-vasculitic non-cytophagic lobular panniculits. Giant and epitheloid cell granulomas were found in liver (pt 1, 5), synovium (pt 2), lymph node (pt 3, 5), colon (pt 3), subcutaneous fat (pt 3), dermis and lung (pt 4). Immunohistochemical study of the granulomas revealed the presence of abundant CD68+ macrophages, numerous CD4+ T lymphocytes and few CD8+ cells. TNF stainings were only weakly positive, conversely abundant IL-6 staining was apparent, especially in the corona of lymphocytes. Despite steroid and cyclosporin treatment, the course was progressive in patient 1 with severe lung involvement and death from respiratory insufficiency at age 14. In patients 2, 3, 4 and 5, therapy with anti-TNF MoAbs allowed better disease control. Infantile onset Panniculitis with Systemic Granulomatosis may be a potentially fatal granulomatous disease in children. Although the response to anti-TNF MoAbs in four of our patients is of note, the paucity of TNF with overwhelming presence of IL-6 in situ in granulomas suggest the implication of alternative immune-inflammatory pathways. The role of the Th17 pthway is currently under investigation

Different pattern of synthesis and secretion of IL-1beta in patients with CIAS-1 and TNFRSF1A mutations responding to IL-1 blockade

Methods Monocytes from 6 CINCA and 4 TRAPS patients selected for treatment with Anakinra were activated with 1 μg/ml of LPS for 3 hours, at baseline and after 7 days from the beginning of the treatment. For comparison, monocytes from 24 healthy donors were also studied. Intracellular pro-IL-1β and secreted IL-1β were analysed by Western blotting and ELISA before and after a short exposure (15 min) to exogenous ATP that accelerates IL-1β secretion.

Disease-associated CIAS1 mutations induce monocyte death, revealing low-level mosaicism in mutation-negative cryopyrin-associated periodic syndrome patients

Cryopyrin-associated periodic syndrome (CAPS) is a spectrum of systemic autoinflammatory disorders in which the majority of patients have mutations in the cold-induced autoinflammatory syndrome (CIAS)1 gene. Despite having indistinguishable clinical features, some patients lack CIAS1 mutations by conventional nucleotide sequencing. We recently reported a CAPS patient with mosaicism of mutant CIAS1, and raised the possibility that CIAS1 mutations were overlooked in "mutation-negative" patients, due to a low frequency of mosaicism. To determine whether there were latent mutant cells in "mutation-negative" patients, we sought to identify mutation-associated biologic phenotypes of patients' monocytes. We found that lipopolysaccharide selectively induced necrosis-like cell death in monocytes bearing CIAS1 mutations. Monocyte death correlated with CIAS1 up-regulation, was dependent on cathepsin B, and was independent of caspase-1. Cell death was intrinsic to CIAS1-mutated monocytes, was not mediated by the inflammatory milieu, and was independent of disease severity or anti-IL-1 therapy. By collecting dying monocytes after lipopolysaccharide treatment, we succeeded in enriching CIAS1-mutant monocytes and identifying low-level CIAS1-mosaicism in 3 of 4 "mutation-negative" CAPS patients. Our findings reveal a novel effect of CIAS1 mutations in promoting necrosis-like cell death, and demonstrate that CIAS1 mosaicism plays an important role in mutation-negative CAPS patients.

Phenotype–Genotype Analysis of Cryopyrin-Associated Periodic Syndromes (CAPS): Description of a Rare Non-Exon 3 and a Novel CIAS1 Missense Mutation

We describe in this paper the phenotype-genotype analysis of a Brazilian cohort of patients with cryopyrin-associated periodic syndromes (CAPS). Patient 1 presented with an urticarial rash and recurrent fever exacerbated by cold weather, arthritis, and anterior uveitis, thus, receiving a clinical diagnosis of familial cold autoinflammatory syndrome. CIAS1 sequencing identified the T436I mutation, previously associated to a clinical phenotype of chronic infantile neurological cutaneous and articular/neonatal onset multisystem inflammatory disease. Patient 2 developed a papular exanthema with daily fever shortly after birth, frontal bossing, patellae enlargement, and cognitive and motor impairments. Sequencing identified the exceedingly rare G755R CIAS1 mutation in exon 4. Patient 3 developed skin rash and articular symptoms 6 h after birth, followed by aseptic meningitis. He was found to have the novel C148Y missense mutation in CIAS1. This report expands the spectrum of CIAS1 mutations associated to clinical disease, suggests that the same mutation can be associated with different clinical syndromes, and supports the evidence that CAPS patients should always be screened for mutations outside exon 3.

New CIAS1 mutation and anakinra efficacy in overlapping of Muckle-Wells and familial cold autoinflammatory syndromes

Muckle-Wells syndrome (MWS) and familial cold autoinflammatory syndrome (FCAS) are rare periodic fevers associated with CIAS1 mutations. A third entity, the chronic infantile neurological, cutaneous, articular (CINCA) syndrome was also recently associated with mutation in the same gene. A phenotypic and genotypic continuum seems to exist from the most benign (FCAS) to the most severe forms (CINCA). Although a CIAS1 mutation can be associated with two different phenotypes. We report a family of three patients exhibiting the MWS and FCAS phenotypes. These phenotypes were associated with a novel missense mutation in CIAS1. Anakinra controlled inflammatory flares in the three patients. FCAS, MWS and CINCA could be different phenotype expressions of the same disease.

Coexistent MEFV and CIAS1 mutations manifesting as familial Mediterranean fever plus deafness

We report two individuals with familial Mediterranean fever (FMF) confirmed on genetic testing who also had progressive deafness and mutations in the CIAS1 gene. This is the first report of...

Microbial Pathogen-Induced Necrotic Cell Death Mediated by the Inflammasome Components CIAS1/Cryopyrin/NLRP3 and ASC

Cryopyrin (CIAS1, NLRP3) and ASC are components of the inflammasome, a multiprotein complex required for caspase-1 activation and cytokine IL-1beta production. CIAS1 mutations underlie autoinflammation characterized by excessive IL-1beta secretion. Disease-associated cryopyrin also causes a program of necrosis-like cell death in macrophages, the mechanistic details of which are unknown. We find that patient monocytes carrying disease-associated CIAS1 mutations exhibit excessive necrosis-like death by a process dependent on ASC and cathepsin B, resulting in spillage of the proinflammatory mediator HMGB1. Shigella flexneri infection also causes cryopyrin-dependent macrophage necrosis with features similar to the death caused by mutant CIAS1. This necrotic death is independent of caspase-1 and IL-1beta, and thus independent of the inflammasome. Furthermore, necrosis of primary macrophages requires the presence of Shigella virulence genes. While similar proteins mediate pathogen-induced cell death in plants, this report identifies cryopyrin as an important host regulator of programmed pathogen-induced necrosis in animals, a process we term pyronecrosis.

Pattern of interleukin‐1β secretion in response to lipopolysaccharide and ATP before and after interleukin‐1 blockade in patients with CIAS1 mutations

To examine the synthesis, processing, and secretion of interleukin-1beta (IL-1beta), as well as the clinical and biologic effects of IL-1 blockade, in patients with chronic infantile neurologic, cutaneous, articular (CINCA) syndrome and Muckle-Wells syndrome (MWS), in an effort to understand the molecular mechanisms linking mutations of the CIAS1 gene and IL-1beta hypersecretion, and the underlying response to IL-1 receptor antagonist (IL-1Ra). Six patients with CINCA syndrome or MWS were treated with IL-1Ra and followed up longitudinally. Monocytes obtained from the patients and from 24 healthy donors were activated with lipopolysaccharide (LPS) for 3 hours, and intracellular and secreted IL-1beta levels were determined by Western blotting and enzyme-linked immunosorbent assay before and after exposure to exogenous ATP. LPS-induced IL-1beta secretion was markedly increased in monocytes from patients with CIAS1 mutations. However, unlike in healthy subjects, secretion of IL-1beta was not induced by exogenous ATP. Treatment with IL-1Ra resulted in a dramatic clinical improvement, which was paralleled by an early and strong down-regulation of LPS-induced IL-1beta secretion by the patients' cells in vitro. Our results showed that the requirements of ATP stimulation for IL-1beta release observed in healthy individuals are bypassed in patients bearing CIAS1 mutations. This indicates that cryopyrin is the direct target of ATP and that the mutations release the protein from the requirement of ATP for activation. In addition, the dramatic amelioration induced by IL-1Ra treatment is at least partly due to the strong decrease in IL-1beta secretion that follows the first injections of the antagonist. These findings may have implications for other chronic inflammatory conditions characterized by increased IL-1beta.

Autoinflammatory syndromes with a dermatological perspective

The term autoinflammatory syndromes describes a distinct group of systemic inflammatory diseases apparently different from infectious, autoimmune, allergic and immunodeficient ones. Originally, it was almost synonymous with clinically defined hereditary periodic fever syndromes, including familial Mediterranean fever, hyper immunoglobulin D syndrome with periodic fever and tumor necrosis factor receptor-associated periodic syndrome. Similar but distinct periodic fever syndromes accompanied by urticarial rash, familial cold autoinflammatory syndrome, Muckle-Wells syndrome and chronic infantile neurological cutaneous articular syndrome, have all been reportedly associated with CIAS1 mutations and are collectively called cryopyrin-associated periodic syndromes. Consequently, the concept of autoinflammatory syndromes has been spread to contain other systemic inflammatory diseases: rare hereditary diseases with or without periodic fevers, such as pyogenic sterile arthritis, pyoderma gangrenosum and acne syndrome, Blau syndrome and chronic recurrent multifocal osteomyelitis, and the more common collagen disease-like diseases, such as Behcet's disease, Crohn's disease, sarcoidosis and psoriatic arthritis. These diseases are all caused by or associated with mutations of genes regulating innate immunity and have common clinical features accompanied with activation of neutrophils and/or monocytes/macrophages. In this review, major autoinflammatory syndromes are summarized and the pathophysiology of related skin disorders is discussed in association with dysregulated innate immune signaling.

The clinical continuum of cryopyrinopathies: Novel CIAS1 mutations in North American patients and a new cryopyrin model

The cryopyrinopathies are a group of rare autoinflammatory disorders that are caused by mutations in CIAS1, encoding the cryopyrin protein. However, cryopyrin mutations are found only in 50% of patients with clinically diagnosed cryopyrinopathies. This study was undertaken to investigate the structural effect of disease-causing mutations on cryopyrin, in order to gain better understanding of the impact of disease-associated mutations on protein function. We tested for CIAS1 mutations in 22 patients with neonatal-onset multisystem inflammatory disease/chronic infantile neurologic, cutaneous, articular syndrome, 12 with Muckle-Wells syndrome (MWS), 18 with familial cold-induced autoinflammatory syndrome (FCAS), and 3 probands with MWS/FCAS. In a subset of mutation-negative patients, we screened for mutations in proteins that are either homologous to cryopyrin or involved in the caspase 1/interleukin-1beta signaling pathway. CIAS1 and other candidate genes were sequenced, models of cryopyrin domains were constructed using structurally homologous proteins as templates, and disease-causing mutations were mapped. Forty patients were mutation positive, and 7 novel mutations, V262A, C259W, L264F, V351L, F443L, F523C, and Y563N, were found in 9 patients. No mutations in any candidate genes were identified. Most mutations mapped to an inner surface of the hexameric ring in the cryopyrin model, consistent with the hypothesis that the mutations disrupt a closed form of cryopyrin, thus potentiating inflammasome assembly. Disease-causing mutations correlated with disease severity only for a subset of known mutations. Our modeling provides insight into potential molecular mechanisms by which cryopyrin mutations can inappropriately activate an inflammatory response. A significant number of patients who are clinically diagnosed as having cryopyrinopathies do not have identifiable disease-associated mutations.

A CIAS1 mutation in a Japanese girl with familial cold autoinflammatory syndrome

Abbreviations ACU acquired cold urticaria CIAS1 cold-induced autoinflammatory syndrome 1 CINCA chronic infantile neurologic cutaneous and articular FCAS familial cold autoinflammatory syndrome MWS Muckle-Wells syndrome NOMID neonatal-onset multisystem inflammatory disease Here we describe a Japanese girl with familial cold autoinflammatory syndrome (FCAS) and identify the mutation in the CIAS1 gene, encoding a cryopyrin protein expressed mainly in phagocytic cells. A 14-year-old girl was referred to our hospital because of a rash, fever, and arthralgia. From 4 months of age, she had suffered from intermittent episodes of pruritic rash. At the age of 13 years, she had developed severe pain in the right hip joint and a gait disturbance and had been admitted to a local hospital. The patient then experienced intermittent right arthralgia and lumbago and was treated with nonsteroidal anti-inflammatory drugs. Physical examination revealed discrete urticarial plaques 2–10 mm in diameter surrounded by macular erythema distributed across the cheeks and lower and upper extremities (Fig. 1a). After exposure to cold air, the urticarial rash worsened and conjunctivitis appeared. The ice cube test result was negative. The patient’s father and paternal grandmother seemed to also have a similar urticarial rash and conjunctivitis after cold exposure. Laboratory tests showed an elevated white blood cell count of 13,500/μl with 79% neutrophils, an elevated erythrocyte sedimentation rate of 44 mm/h, and an elevated C-reactive protein concentration of 4.4 mg/dl. Skin biopsy revealed moderate superficial and minimal deep perivascular inflammation with interstitial neutrophils and mononuclear cells (Fig. 1b). Patients have long been diagnosed as having acquired cold urticaria (ACU) because FCAS has not been reported in Japan. However, in this case, an ice cube test was negative, and the patient was suspected Eur J Pediatr (2008) 167:245–247 DOI 10.1007/s00431-007-0451-x