Regression Approaches to Assess Effect of Treatments That Arrest Progression of Symptoms.

Motivated by a small sample example in neonatal onset multisystem inflammatory disease (NOMID), we propose a method that can be used when the interest is testing for an association between a changes in disease progression with start of treatment compared to historical disease progression prior to treatment. Our method estimates the longitudinal trajectory of the outcome variable and adds an interaction term between an intervention indicator variable and the time since initiation of the intervention. This method is appropriate for a situation in which the intervention slows or arrests the effect of the disease on the outcome, as is the case in our motivating example. By simulation in small samples and restricted sets of treatment initiation times, we show that the generalized estimating equations (GEE) formulation with small sample adjustments can bound the Type I error rate better than GEE and linear mixed models without small sample adjustments. Permutation tests (permuting the time of treatment initiation) is another valid approach that can also be useful. We illustrate the methodology through an application to a prospective cohort of NOMID patients enrolled at the NIH clinical center.

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

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

Treating inflammation by blocking interleukin-1 in humans.

IL-1 is a master cytokine of local and systemic inflammation. With the availability of specific IL-1 targeting therapies, a broadening list of diseases has revealed the pathologic role of IL-1-mediated inflammation. Although IL-1, either IL-1α or IL-1ß, was administered to patients in order to improve bone marrow function or increase host immune responses to cancer, these patients experienced unacceptable toxicity with fever, anorexia, myalgias, arthralgias, fatigue, gastrointestinal upset and sleep disturbances; frank hypotension occurred. Thus it was not unexpected that specific pharmacological blockade of IL-1 activity in inflammatory diseases would be beneficial. Monotherapy blocking IL-1 activity in a broad spectrum of inflammatory syndromes results in a rapid and sustained reduction in disease severity. In common conditions such as heart failure and gout arthritis, IL-1 blockade can be effective therapy. Three IL-1blockers have been approved: the IL-1 receptor antagonist, anakinra, blocks the IL-1 receptor and therefore reduces the activity of IL-1α and IL-1ß. A soluble decoy receptor, rilonacept, and a neutralizing monoclonal anti-interleukin-1ß antibody, canakinumab, are also approved. A monoclonal antibody directed against the IL-1 receptor and a neutralizing anti-IL-1α are in clinical trials. By specifically blocking IL-1, we have learned a great deal about the role of this cytokine in inflammation but equally important, reducing IL-1 activity has lifted the burden of disease for many patients.

[Autoinflammatory diseases and kidney involvement]. / Autovospalitel'nye zabolevaniia i porazhenie pochek.

Autoinflammatory disease (AID) is a new concept formulated from the results of studying the pathogenesis of familial periodic fevers, a heterogeneous group of genetically determined diseases characterized by causelessly recurrent exacerbations of the inflammatory process due to genetically determined disorders of innate immunity and accompanied by uncontrolled hypersecretion of interleukin-1 (IL-1). These mechanisms were a basic model for understanding a wide range of rheumatologic and other inflammatory diseases of the internal organs. The late diagnosis of AIDs and their ineffective treatment increase the risk for the development and progression of secondary AA amyloidosis. Elaboration of both clinical and effective laboratory criteria for diagnosing autoinflammation is of great importance for determining the tactics of anti-inflammatory therapy and prevention of complications.

Real-life effectiveness of canakinumab in cryopyrin-associated periodic syndrome.

OBJECTIVE: Cryopyrin-associated periodic syndrome (CAPS) is a heterogeneous group of diseases characterized by excessive IL-1ß release resulting in severe systemic and organ inflammation. Canakinumab targets IL-1ß and is approved at standard dose for children and adults with all CAPS phenotypes. Limited data are available for the real-life effectiveness of canakinumab in patients living with CAPS. Therefore the aim of the study was to evaluate the real-life dosing and effectiveness of canakinumab in CAPS. METHODS: A multi-centre study of consecutive children and adults with CAPS treated with canakinumab was performed. Demographics, CAPS phenotype and disease activity, inflammatory markers and canakinumab treatment strategy were recorded. Treatment response was assessed using CAPS disease activity scores, CRP and/or serum amyloid A levels. Comparisons between age groups, CAPS phenotypes and centres were conducted. RESULTS: A total of 68 CAPS patients at nine centres were included. All CAPS phenotypes were represented. Thirty-seven (54%) patients were females, the median age was 25 years and 27 (40%) were children, and the median follow-up was 28 months. Overall, complete response (CR) was seen in 72% of CAPS patients, significantly less often in severe (14%) than in mild CAPS phenotypes (79%). Only 53% attained CR on standard dose canakinumab. Dose increase was more commonly required in children (56%) than in adults (22%). Centres with a treat-to-target approach had significantly higher CR rates (94 vs 50%). CONCLUSION: Real-life effectiveness of canakinumab in CAPS was significantly lower than in controlled trials. Treat-to-target strategies may improve the outcome of children and adults living with CAPS.

Long-term safety profile of anakinra in patients with severe cryopyrin-associated periodic syndromes.

OBJECTIVE: Anakinra is approved for the treatment of RA and cryopyrin-associated periodic syndromes (CAPS). While the anakinra safety profile is well established in RA, the long-term safety profile in severe CAPS is less well documented and will therefore be discussed in this report. METHODS: A prospective, open-label, single centre, clinical cohort study was conducted at the National Institutes of Health in the USA, from 2003 to 2010, investigating the efficacy and safety of anakinra treatment for up to 5 years in 43 patients with CAPS. Safety was evaluated using adverse event (AE) reports, laboratory assessments, vital signs and diary reports. RESULTS: In total, 1233 AEs were reported during the study, with a yearly rate of 7.7 AEs per patient. The event rate decreased over time, and dose escalation during the study did not affect AE frequency. Anakinra had similar safety profiles in adults and children. The most frequently reported AEs were typical CAPS disease symptoms such as headache and arthralgia. Injection site reactions occurred mainly during the first month of anakinra treatment. In total, 14 patients experienced 24 serious AEs (SAEs), all of which resolved during the study period. The most common types of SAEs were infections such as pneumonia and gastroenteritis. There were no permanent discontinuations of treatment due to AEs. CONCLUSION: In this study anakinra treatment of patients with severe CAPS for up to 5 years was safe and well tolerated both in paediatric and adult patients, with most AEs emerging during the first months after treatment initiation. TRIAL REGISTRATION: ClincialTrials.gov, clinicaltrials.gov, NCT00069329.

NLRP3 mediates osteolysis through inflammation-dependent and -independent mechanisms.

Activating-mutations in NOD-like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) cause neonatal-onset multisystem inflammatory disease. However, the ontogeny of skeletal anomalies in this disorder is poorly understood. Mice globally expressing the D301N mutation in Nlrp3 (D303N in human) model the human phenotype, including systemic inflammation and skeletal deformities. To gain insights into the skeletal manifestations, we generated mice in which the expression of D301N Nlrp3 (Nlrp3( D301N)) is restricted to myeloid cells. These mice exhibit systemic inflammation and severe osteopenia (∼ 60% lower bone mass) similar to mice globally expressing the knock-in mutation, consistent with the paradigm of innate immune-driven cryopyrinopathies. Because systemic inflammation may indirectly affect bone homeostasis, we engineered mice in which Nlrp3( D301N) is expressed specifically in osteoclasts, the cells that resorb bone. These mice also develop ∼ 50% lower bone mass due to increased osteolysis, but there is no systemic inflammation and no change in osteoclast number. Mechanistically, aside from its role in IL-1ß maturation, Nlrp3( D301N) expression enhances osteoclast bone resorbing ability through reorganization of actin cytoskeleton while promoting the degradation of poly(ADP-ribose) polymerase 1, an inhibitor of osteoclastogenesis. Thus, NLRP3 inflammasome activation is not restricted to the production of proinflammatory mediators but also leads to cytokine-autonomous responses.

Impaired cytokine responses in patients with cryopyrin-associated periodic syndrome (CAPS).

Cryopyrin-associated periodic syndrome (CAPS) is characterized by dysregulated inflammation with excessive interleukin (IL)-1ß activation and secretion. Neonatal-onset multi-system inflammatory disease (NOMID) is the most severe form. We explored cytokine responses in 32 CAPS patients before and after IL-1ß blocking therapy. We measured cytokines produced by activated peripheral blood monuclear cells (PBMCs) from treated and untreated CAPS patients after stimulation for 48 h with phytohaemagglutinin (PHA), PHA plus IL-12, lipopolysaccharide (LPS) or LPS plus interferon (IFN)-γ. We measured IL-1ß, IL-6, IL-10, tumour necrosis factor (TNF), IL-12p70 and IFN-γ in the supernatants. PBMCs from three untreated CAPS patients were cultured in the presence of the IL-1ß blocker Anakinra. Fifty healthy individuals served as controls. CAPS patients had high spontaneous production of IL-1ß, IL-6, TNF and IFN-γ by unstimulated cells. However, stimulation indexes (SIs, ratio of stimulated to unstimulated production) of these cytokines to PHA and LPS were low in NOMID patients compared to controls. Unstimulated IL-10 and IL-12p70 production was normal, but up-regulation after PHA and LPS was also low. LPS plus IFN-γ inadequately up-regulated the production of IL-1ß, IL-6, TNF and IL-10 in CAPS patients. In-vitro but not in-vivo treatment with Anakinra improved SIs by lowering spontaneous cytokine production. However, in-vitro treatment did not improve the low stimulated cytokine levels. Activating mutations in NLRP3 in CAPS are correlated with poor SIs to PHA, LPS and IFN-γ. The impairment in stimulated cytokine responses in spite of IL-1ß blocking therapy suggests a broader intrinsic defect in CAPS patients, which is not corrected by targeting IL-1ß.

Efficacy and safety of canakinumab therapy in paediatric patients with cryopyrin-associated periodic syndrome: a single-centre, real-world experience.

OBJECTIVE: The aim of this study was to determine the short- and long-term efficacy and safety of 8-weekly canakinumab therapy in children with cryopyrin-associated periodic syndromes (CAPS) in routine clinical practice. METHODS: A single-centre observational study was performed. Patients were assessed every 8 weeks at a dedicated clinic. Standardized assessments were the 10-domains DAS for CAPS, acute phase reactants (APRs), physician's global assessment of disease activity, Child Health Assessment Questionnaire (CHAQ) and Child Health Questionnaire Parent Form 28 (CHQPF-28). The primary endpoint was clinical improvement, defined as a reduction of DAS score 8 weeks after commencing therapy. Secondary endpoints included sustained clinical improvement in APRs, relapses, CHAQ score and CHQPF-28 score. RESULTS: Ten children with CAPS [eight Muckle-Wells syndrome (MWS), two chronic infantile cutaneous neurological articular (CINCA); median age 6.3 years] received 8-weekly canakinumab treatments at 2-8.7 mg/kg for a median of 21 months (range 12-31 months). Nine of 10 patients improved after the first dose: baseline median DAS of 7.5/20 decreased to 3.5/20 at 8 weeks (P = 0.04). This clinical improvement was sustained at a median follow-up of 21 months (range 12-31 months). Children with CINCA required higher doses of canakinumab than those with MWS. CHAQ and CHQ scores indicated improvement in functioning and health-related quality of life (HRQoL). Treatment was well tolerated, with no injection site reactions and no serious infections. CONCLUSION: Canakinumab, although costly, is a safe and effective treatment for CAPS in children, leading to sustained improvement in disease activity, serological markers, functional ability and HRQoL.

Case Report: A neonatal case of cryopyrin-associated periodic syndrome with severe funisitis and neonatal asphyxia.

Cryopyrin-associated periodic syndrome (CAPS) is a genetic disorder and autoinflammatory disease characterized by chronic inflammation throughout the body. The most severe form of CAPS, Chronic Infantile Neurologic Cutaneous, and Articular (CINCA) syndrome, also known as Neonatal Onset Multisystem Inflammatory Disease (NOMID), has three main features: skin rash, CNS involvement, and joint symptoms. Although these symptoms are typically reported shortly after birth, there have been a few reports of prenatal inflammation. Here, we report our experience managing a case of a CAPS infant born in severe neonatal asphyxia due to a ruptured cord associated with severe funisitis. The baby was born at 38 weeks and 6 days of gestation, weighing 2,898 g, through an ultra-emergency Caesarian section prompted by variable deceleration. The Apgar score was 1 point at 1 min and 4 points at 5 min, necessitating intensive care due to hypoxic-ischemic encephalopathy. Upon delivery, it was observed that the umbilical cord had partially ruptured at the site of attachment to the baby, accompanied by arterial hemorrhage. Umbilical cord rupture was considered to be the cause of the sudden decrease in fetal heart rate. Pathological examination also showed that the inflammation of the cord was more severe on the side attached to the fetus and on the arterial side, suggesting that the inflammation had extended from the fetus. The father carried a genetic mutation associated with CINCA syndrome/NOMID (NLRP3 c.2068G>A p.Glu690Lys Hetero), which was also found in the child. Histopathologic examination of the placenta and umbilical cord can provide crucial insights into the intrauterine onset of inflammation, which is the first manifestation of CINCA syndrome/NOMID in newborns. It should be noted that births with a genetic predisposition to CAPS may have complications related to the placenta and umbilical cord.

Clinical characteristics of Chinese neonates with neonatal-onset multisystem inflammatory disease: a case report and literature review.

Background: Neonatal-onset multisystem inflammatory disease (NOMID) is a rare and severe autoinflammatory disease caused by mutations of the NLRP3 gene and is characterized by a skin rash, fever, arthropathy, and neurologic manifestations. We herein report a neonatal case with recurrent rash, fever, and meningitis from 12 h after birth, and NOMID was diagnosed during the neonatal period. We also reviewed the clinical characteristics and genetic mutations of previously reported Chinese neonates with NOMID. Case presentation and literature review: NOMID is rare in China, and there have been over 100 cases uncovered thus far, including ours. The patient we reported here was the youngest among the confirmed Chinese cases and had the de novo mutation c.1210G>C (p.V404L) in exon 4 of the NLRP3 gene, which has not been reported previously. All 25 patients manifested recurrent urticaria-like rash, and 24 were febrile. Of the 23 patients with genetic data available, all had NLRP3 mutations. The primary treatment of these patients entailed glucocorticoids and immunosuppressants; however, the IL-1 inhibitor was rarely used due to its current unavailability in China. One patient was cured by umbilical cord blood stem cell transplantation (UCBT), which provided an alternative treatment. Conclusion: We recommend that NOMID be considered for neonates with recurrent rash, fever, and aseptic meningitis. However, further research on underlying mechanisms and therapeutic regimens in China is necessary to provide improved management.

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

BACKGROUND: NLRP3-associated autoinflammatory diseases (NLRP3-AID) are rare genetic autoinflammatory diseases characterized by chronic inflammation and an urticaria-like rash. We report an unusual presentation of severe NLRP3-AID resulting in a significant diagnostic delay of more than three decades. CASE PRESENTATION: The patient presented with early-onset serositis as well as prominent peripheral eosinophilia with organ infiltration, in the absence of the classic urticaria-like rash. DNA analysis by next generation sequencing revealed a sporadic class 4 mutation c.1991T > C (p.Met662Thr) in the NLRP3 gene, confirming a diagnosis of NLRP3-AID at 36 years old. Although treatment with anti-interleukin 1 agent led to clinical remission, irreversible sequelae, namely intellectual disability and deafness, remained. CONCLUSION: This case highlights unique manifestations of NLRP3-AID, namely the absence of urticaria-like rash, eosinophilic organ infiltration, and pseudoseptic serositis. In order to avoid diagnostic delay and its dire consequences, NLRP3-AID should be suspected in patients displaying autoinflammatory features combined with serum and tissue eosinophilia and/or marked serositis, regardless of skin involvement.

Case Report: Infantile Urticaria as a Herald of Neonatal Onset Multisystem Inflammatory Disease With a Novel Mutation in NLRP3.

Neonatal multisystem onset inflammatory disorder (NOMID) is a severe autoinflammatory syndrome that can have an initial presentation as infantile urticaria. Thus, an immediate recognition of the clinical symptoms is essential for obtaining a genetic diagnosis and initiation of early therapies to prevent morbidity and mortality. Herein, we describe a neonate presenting with urticaria and systemic inflammation within hours after birth who developed arthropathy and neurologic findings. Pathologic evaluation of the skin revealed an infiltration of lymphocytes, eosinophils, and scattered neutrophils. Genetic analysis identified a novel heterozygous germline variant of unknown significance in the NLRP3 gene, causing the missense mutation M408T. Variants of unknown significance are common in genetic sequencing studies and are diagnostically challenging. Functional studies of the M408T variant demonstrated enhanced formation and activity of the NLRP3 inflammasome, with increased cleavage of the inflammatory cytokine IL-1ß. Upon initiation of IL-1 pathway blockade, the infant had a robust response and improvement in clinical and laboratory findings. Our experimental data support that this novel variant in NLRP3 is causal for this infant's diagnosis of NOMID. Rapid assessment of infantile urticaria with biopsy and genetic diagnosis led to early recognition and targeted anti-cytokine therapy. This observation expands the NOMID-causing variants in NLRP3 and underscores the role of genetic sequencing in rapidly identifying and treating autoinflammatory disease in infants. In addition, these findings highlight the importance of establishing the functional impact of variants of unknown significance, and the impact this knowledge may have on therapeutic decision making.

Diagnosis and Management of the Cryopyrin-Associated Periodic Syndromes (CAPS): What Do We Know Today?

The cryopyrin-associated periodic syndromes (CAPS) are usually caused by heterozygous NLRP3 gene variants, resulting in excessive inflammasome activation with subsequent overproduction of interleukin (IL)-1ß. The CAPS spectrum includes mild, moderate, and severe phenotypes. The mild phenotype is called familial cold autoinflammatory syndrome (FCAS), the moderate phenotype is also known as Muckle-Wells syndrome (MWS), and the neonatal-onset multisystem inflammatory disease (NOMID)/chronic infantile neurologic cutaneous articular syndrome (CINCA) describes the severe phenotype. The CAPS phenotypes display unspecific and unique clinical signs. Dermatologic, musculoskeletal, ocular, otologic, and neurologic disease symptoms combined with chronic systemic inflammation are characteristic. Nevertheless, making the CAPS diagnosis is challenging as several patients show a heterogeneous multi-system clinical presentation and the spectrum of genetic variants is growing. Somatic mosaicisms and low-penetrance variants lead to atypical clinical symptoms and disease courses. To avoid morbidity and to reduce mortality, early diagnosis is crucial, and a targeted anti-IL-1 therapy should be started as soon as possible. Furthermore, continuous and precise monitoring of disease activity, organ damage, and health-related quality of life is important. This review summarizes the current evidence in diagnosis and management of patients with CAPS.

Bilateral Optic Disc Swelling as a Plausible Common Ocular Sign of Autoinflammatory Diseases: Report of Three Patients with Blau Syndrome or Cryopyrin-Associated Periodic Syndrome.

The aim of this study is to describe bilateral optic disc swelling in three consecutive patients with Blau syndrome or cryopyrin-associated periodic syndrome at a single institution. Case 1 was a 30-year-old woman receiving 25 mg etanercept twice weekly who had been diagnosed as early-onset sarcoidosis by biopsy of skin rashes at 5 months old and genetically diagnosed with Blau syndrome with CARD15/NOD2 mutation (N670K) at 13 years old. At 10 years old, she began to have uveitis with optic disc swelling in both eyes, resulting in macular degeneration and optic disc atrophy at 17 years old only when etanercept was introduced. Case 2 was a 21-year-old man receiving adalimumab every 2 weeks who had been diagnosed as early-onset sarcoidosis by biopsy of skin rashes at 1.5 years old and genetically diagnosed as Blau syndrome with CARD15/NOD2 mutation (C495Y) at 5 years old. At 8 years old, around the time of adalimumab introduction, he began to show bilateral optic disc swelling which continued until the age of 16 years when the dose of adalimumab was increased. Case 3 was a 20-year-old woman receiving canakinumab every 8 weeks for systemic symptoms such as fever, headache, vomiting, and abdominal pain and later for sensorineural hearing disturbance on both sides. She had been diagnosed genetically with cryopyrin-associated periodic syndrome with NLRP3 mutation (Y859C) at 7 years old. At 5 years old, she was found to have bilateral optic disc swelling, which continued until the age of 10 years when she began receiving canakinumab (IL-1ß inhibitor). Bilateral optic disc swelling might be tentatively designated as a plausible common ocular feature, if it occurred, in autoinflammatory diseases to pay more attention to ophthalmic complications in rare diseases.

Spectrum of Systemic Auto-Inflammatory Diseases in India: A Multi-Centric Experience.

Background: Systemic autoinflammatory diseases (SAID) are rare inherited disorders involving genes regulating innate immune signaling and are characterized by periodic or chronic multi-systemic inflammation. Objective: To describe spectrum of clinical, immunological, molecular features, and outcomes of patients with SAID in India. Methods: Request to share data was sent to multiple centers in India that are involved in care and management of patients with Inborn Errors of Immunity. Six centers provided requisite data that were compiled and analyzed. Results: Data on 107 patients with SAID were collated-of these, 29 patients were excluded due to unavailability of complete information. Twelve patients (15%) had type 1 interferonopathies, 21 (26%) had diseases affecting inflammasomes, 30 patients (41%) had non-inflammasome related conditions and 1five patients (19%) had Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA). Type1 interferonopathies identified in the cohort included patients with Deficiency of Adenosine Deaminase 2 (DADA2) (six patients; five families); STING-associated vasculopathy infantile-onset (SAVI) (three patients, one family); Spondyloenchondro-dysplasia with Immune Dysregulation (SPENCD) (two patients). Diseases affecting inflammasomes include Mevalonate Kinase Deficiency (eight patients); Cryopyrin-Associated Periodic Syndromes (CAPS) (seven patients); NLR Family, Pyrin domain-containing 12 (NLRP12) (two patients); Familial Mediterranean fever (FMF) (two patients); Autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) (two patients). TNF receptor-associated periodic syndrome (TRAPS) (three patients); A20 haploinsufficiency (four patients); Deficiency of Interleukin 1 Receptor Antagonist (DIRA) (two patients) were categorized as non-inflammasome related conditions. There were significant delays in diagnosis Corticosteroids and other immunosuppressive agents were used for treatment as anti-IL-1 drugs and other biological agents were and still are not available in India. Eight (16.3%) patients had so far succumbed to their illness. Conclusions: This is the first nationwide cohort of patients with SAID from India. Clinical manifestations were diverse. Overlapping of clinical features with other relatively common rheumatological disorders often resulted in delays in diagnosis. More nationwide efforts are needed to enhance awareness of SAID among health care professionals and there is an urgent need to make targeted immunotherapies universally available.

Detection of a novel mutation in NLRP3/CIAS1 gene in an Indian child with Neonatal-Onset Multisystem Inflammatory Disease (NOMID).

Neonatal-Onset Multisystem Inflammatory Disease (NOMID) or Chronic Infantile Neurologic Cutaneous Articular (CINCA) syndrome is a monogenic autoinflammatory disorder characterized by urticarial skin rash, fever, chronic meningitis and joint manifestations. Here we report a case of an Indian male child who presented at the age of 9 months with fever, respiratory distress, urticarial skin rash, arthritis, and neuroregression. Suspecting NOMID/CINCA syndrome, the child's blood was sent to the Jaslok Hospital and Research Centre for mutation analysis of the CIAS1/NLRP3 gene. The DNA was screened for mutations in exon 3 of CIAS1/NLRP3 gene by automated Sanger sequencing. DNA sequencing showed a novel heterozygous c.1813A➔G, p.R605G mutation in exon 3 of CIAS1/NLRP3 gene (ref no NM_001243133.1). His parents tested negative for this mutation. We therefore identified a novel de novo mutation in this family in the CIAS1/NLRP3 gene responsible for the child's clinical features.

Development and effect of antibodies to anakinra during treatment of severe CAPS: sub-analysis of a long-term safety and efficacy study.

Anakinra is an effective, well-tolerated, long-term anti-inflammatory treatment for cryopyrin-associated periodic syndromes (CAPS), yet evidence shows that it can induce the development of anti-drug antibodies (ADA). This analysis aims to determine ADA occurrence in CAPS patients and elucidate their effects on anakinra dosing and drug efficacy. A post hoc analysis was performed on data from a long-term safety and efficacy study in patients with severe CAPS. Patients were initiated on an anakinra dose of 1.0-2.4 mg/kg once daily subcutaneously, which was increased (in 0.5-1.0 mg/kg increments) to 2.0-5.0 mg/kg/day according to clinical need (median 3.1 mg/kg/day). ADA, serum amyloid A (SAA), and C-reactive protein (CRP) levels were measured at various time points, and pharmacokinetic (PK) parameters at 1 and 3 months. Efficacy was evaluated using a diary symptom sum score (DSSS), and SAA and CRP levels were evaluated as proxies of efficacy. Safety was evaluated by an analysis of adverse events (AEs). Anakinra dose levels were unrelated to ADA status. A high proportion of patients with at least one post-baseline assessment developed ADA (83%), the majority (79%) within 3 months. However, anakinra treatment markedly improved symptoms and was effective regardless of the presence of ADA; the annual rates of AEs were comparable between ADA-negative and ADA-positive patients. While ADA are likely to occur in CAPS patients treated with anakinra, our evidence shows that chronic daily subcutaneous treatment with anakinra is safe and effective regardless of the development and presence of ADA.

An NLRP3 Mutation Causes Arthropathy and Osteoporosis in Humanized Mice.

The NLRP3 inflammasome plays a critical role in host defense by facilitating caspase I activation and maturation of IL-1ß and IL-18, whereas dysregulation of inflammasome activity results in autoinflammatory disease. Factors regulating human NLRP3 activity that contribute to the phenotypic heterogeneity of NLRP3-related diseases have largely been inferred from the study of Nlrp3 mutant mice. By generating a mouse line in which the NLRP3 locus is humanized by syntenic replacement, we show the functioning of the human NLRP3 proteins in vivo, demonstrating the ability of the human inflammasome to orchestrate immune reactions in response to innate stimuli. Humanized mice expressing disease-associated mutations develop normally but display acute sensitivity to endotoxin and develop progressive and debilitating arthritis characterized by granulocytic infiltrates, elevated cytokines, erosion of bones, and osteoporosis. This NLRP3-dependent arthritis model provides a platform for testing therapeutic reagents targeting the human inflammasome.