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.

There have been hundreds of reports on mutations in the NLRP3 gene related to NLRP3-associated autoinflammatory disease, but few of these mutations have occurred as both germline and somatic mosaic mutations. In this case-based review, we report a 68-year-old man with an NLRP3-associated autoinflammatory disease. He developed secondary amyloidosis, including a renal and colorectal presentation in his 50 s. Sequencing of the NLRP3 gene revealed an I574F somatic mosaic mutation, which has up to now only been reported in germline mutations. The patient was treated with canakinumab, which had great efficacy not only on the NLRP3-mediated inflammation, but also on the chronic renal failure and proteinuria provoked by secondary renal amyloidosis. To evaluate the effectiveness of canakinumab, we conducted a literature research on renal amyloidosis related to NLRP3-associated autoinflammatory disease treated with canakinumab. Although our patient had a relatively long medical history and greater amounts of proteinuria than other reported cases, canakinumab had great efficacy on renal impairment, in similar to other reported cases. Along with the first report of a late-onset I574F somatic mosaic mutation in NLRP3-associated autoinflammatory disease, this report demonstrates the effectiveness of canakinumab on renal amyloidosis, probably through the way that IL-1β blockade minimizes podocyte injury.

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-1β 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.

Fever and low back pain with radicular symptoms raise concern for epidural abscess or other neuraxial infection, especially in the context of recent epidural anesthesia. Here we present an unusual case with several confounding factors and an unexpected diagnosis.

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 is characterized by periodic fever, rash, and joint pain. Papilledema rarely occurs. We present our series of patients with cryopyrin-associated periodic syndrome who clinically met the diagnostic criteria for Muckle-Wells syndrome and our experience with secondary intracranial hypertension.
Retrospective review of all patients with cryopyrin-associated periodic syndrome at Nationwide Children\'s Hospital from October 2015 to September 2017.
Eighteen children met inclusion criteria: 15 females and three males, aged 1.5 to 16.2 years. Fifteen had periodic fever genetic testing; three had a known genetic defect identified, eight had a defect identified not currently known to be associated with cryopyrin-associated periodic syndrome, and four had no defect identified. Six patients (30%) developed headaches and were diagnosed with secondary intracranial hypertension. Lumbar puncture opening pressures ranged from 28 to 45 cm H2O. Only one patient had papilledema. Initial treatment was medical in all cases, by increasing interleukin-1 inhibitor dose and/or acetazolamide. One patient required a ventriculoperitoneal shunt for headache management. No visual acuity loss was detected. All six patients with secondary intracranial hypertension had a known genetic mutation or genetic variant of unknown significance; five involved the NLRP3 gene.
In our series of 18 patients with cryopyrin-associated periodic syndrome, secondary intracranial hypertension occurred at a higher than expected rate. We suspect that genetic defects involving the NLRP3 gene may be a risk factor. Papilledema was present in only one patient. Physicians treating cryopyrin-associated periodic syndrome should be aware of this vision-threatening association and potential therapeutic approach.

Cryopyrin-associated periodic fever syndrome (CAPS) represents an increasingly recognized disease group entity, with varied presentations. CAPS includes 3 clinical entities, namely, familial cold-induced autoinflammatory syndrome (FCAS; MIM #120100), Muckle-Wells syndrome (MWS; MIM #191900) and chronic inflammatory neurologic cutaneous and articular syndrome (CINCA; MIM #607115); which share several overlapping clinical features. These patients often present with early-onset episodes of fever and rash, and variable systemic signs and symptoms, making it a great mimicker of other systemic autoimmune diseases. The episodes are transient and related to exposure to cold temperature and worsen in the winter season. We hereby present a case presenting with recurrent seasonal fever and rash, diagnosed as FCAS/ MWS overlap based on clinical signs and symptoms and positive testing for NLRP3 gene mutation. We also discuss the clinical presentation and complications of CAPS, chiefly FCAS and MWS, along with the previously described pediatric cases of CAPS. We tried to review the complexities of management of such patients, including the genetic diagnosis and the role of biological therapy. Based on the review of the literature, given the evident broad spectrum of symptoms and signs, use of next-generation sequencing can help in prompt diagnosis and early initiation of biological agents, which may play a great role in reducing the complications that these patients may experience in the long run.

BACKGROUND: Cryopyrin associated periodic syndrome is a rare auto inflammatory disease including three clinical entities with a common genetic cause. Among these three entities, Muckle-Wells syndrome is described as an intermediate phenotype associated with a progressive sensorineural hearing loss and AA amyloidosis. The present case reports a renal AA amyloidosis associated with an IgA nephropathy, revealing a Muckle-Wells syndrome.
METHODS: The case is reported of a 38-years-old patient who presented a renal failure revealed concomitantly with a macroscopic hematuria exploration. Urological investigations were performed with negative results. The patient had no particular background except urticarial rashes, unlabeled inflammatory rheumatism and a grandmother\'s amyloidosis. Renal biopsy revealed glomerular, vascular and interstitial AA amyloidosis associated to an IgA nephropathy. This amyloidosis was known to be a part of Muckle-Wells syndrome, and a NLRP3 gene study confirmed the diagnosis.
CONCLUSIONS: Cryopyrin associated periodic syndrome is a rare disease and the clinical diagnosis suspicion need genetic confirmation. AA amyloidosis is known to happen in Muckle-Wells syndrome. Other occasional renal impairments are described in this syndrome whereas the IgA nephropathy association remains poorly characterized.

BACKGROUND: Muckle-Wells syndrome (MWS) is a rare auto-inflammatory disease characterized by the presence of recurrent urticaria, deafness and amyloidosis. Progressive sensorineural hearing loss (SNHL) is reported to occur in up to 85% of patients occurring in the second and third decades and as early as the first decade in patients with a more severe phenotype, thus potentially having a significant impact on a child\'s development. IL-1 inhibitors, such as Anakinra, have been described to improve systemic inflammation, and stabilize or improve hearing status as well. However, complete resolution of hearing loss has been rarely reported. The objective of this article is to highlight the clinical presentation of a pediatric patient with a severe form of MWS and report on the complete resolution of SNHL with the use of Anakinra.
METHODS: A 3-year-old boy was referred to our hospital to assess for the possibility of MWS given a history of hives and recurrent episodes of fever with a family history of MWS in his mother. Of note, the patient\'s history was significant for conductive hearing loss, speech delay, as well as recurrent acute otitis media episodes. Genetic analysis was performed and diagnosis of MWS was confirmed due to the presence of a NLRP3 gene mutation. Further work-up demonstrated the presence of papilledema and elevation of systemic inflammatory markers for which Canakinumab was initiated. Despite initiation of this treatment, audiogram evaluation demonstrated a new right-sided SNHL. Lumbar puncture also revealed aseptic meningitis. Canakinumab was eventually discontinued and Anakinra initiated. Within 7 months of treatment with Anakinra at 5 mg/kg sc daily, resolution of the SNHL was observed. With further escalation of the Anakinra dose, there was also complete resolution of the aseptic meningitis.
CONCLUSIONS: Progressive hearing loss is a significant finding in patients with MWS. Early screening as well as initiation of Anakinra can lead to complete resolution of SNHL even in a patient with a severe spectrum of MWS. However, as this case demonstrates, longer treatment duration and higher doses of Anakinra may be required to achieve this.

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.
Аутовоспалительные заболевания (АВЗ) - новое понятие, сформулированное по результатам изучения патогенеза семейных периодических лихорадок - гетерогенной группы генетически детерминированных заболеваний, характеризующихся беспричинно повторяющимися обострениями воспалительного процесса вследствие генетически детерминированных нарушений врожденного иммунитета и сопровождающихся бесконтрольной гиперсекрецией интерлейкина-1 (IL-1). Эти механизмы оказались базовой моделью для понимания широкого круга ревматологических и других воспалительных заболеваний внутренних органов. Поздняя диагностика АВЗ и их неэффективное лечение увеличивают риск развития и прогрессирования вторичного АА-амилоидоза. Для определения тактики противовоспалительной терапии, предотвращения осложнений большое значение имеет разработка как клинических, так и эффективных лабораторных критериев диагностики аутовоспаления.