A probable case of Muckle-Wells syndrome

Neonatal treatment of CINCA syndrome

Chronic Infantile Neurological Cutaneous Articular (CINCA) syndrome, also called Neonatal Onset Multisystem Inflammatory Disease (NOMID) is a chronic disease with early onset affecting mainly the central nervous system, bones and joints and may lead to permanent damage. We report two preterm infants with severe CINCA syndrome treated by anti-interleukin-1 in the neonatal period, although, so far, no experience with this treatment in infants younger than three months of age has been reported. A review of the literature was performed with focus on treatment and neonatal features of CINCA syndrome.

CASE REPORT

Two cases suspected to have CINCA syndrome were put on treatment with anakinra in the early neonatal period due to severe clinical presentation. We observed a rapid and persistent decline of clinical signs and systemic inflammation and good drug tolerance. Diagnosis was confirmed in both cases by mutations in the NLRP3/CIAS1-gene coding for cryopyrin. As particular neonatal clinical signs polyhydramnios and endocardial overgrowth are to be mentioned.

CONCLUSION

We strongly suggest that specific treatment targeting interleukin-1 activity should be started early. Being well tolerated, it can be introduced already in neonates presenting clinical signs of severe CINCA syndrome in order to rapidly control inflammation and to prevent life-long disability.

Muckle-Wells cryopyrinopathy: complex phenotyping and response to therapy in a new multiplex kindred

Muckle-Wells syndrome (MWS) is a member of the cryopyrin-associated periodic syndrome family of auto-inflammatory diseases, originally described as a triad of urticaria, sensorineural deafness and amyloidosis. IL-1 blockade is a proven therapy for MWS. The clinical, laboratory and genotypic characteristics of a novel kindred of five individuals with Muckle-Wells syndrome are described. Response to IL-1 blockade therapy in the proband was evaluated. All five affected family members experienced symptoms of multi-organ inflammation. Lead time between symptom onset and diagnosis was approximately 30 years in the proband. Fever was not a universal feature in all affected family members. Anti-IL-1 therapy in the proband resulted in improvements in patient-reported symptoms, inflammatory markers, auditory acuity and reversal of her infertility. Muckle-Wells syndrome is a rare, multisystem, auto-inflammatory syndrome. Delay in diagnosis prevents effective treatment. We propose reversal of infertility to be among the potential benefits of IL-1 inhibition in this disease.

Somatic NLRP3 mosaicism in Muckle-Wells syndrome. A genetic mechanism shared by different phenotypes of cryopyrin-associated periodic syndromes

: Familial cold autoinflammatory syndrome, Muckle-Wells syndrome (MWS), and chronic, infantile, neurological, cutaneous and articular (CINCA) syndrome are dominantly inherited autoinflammatory diseases associated to gain-of-function NLRP3 mutations and included in the cryopyrin-associated periodic syndromes (CAPS). A variable degree of somatic NLRP3 mosaicism has been detected in ≈35% of patients with CINCA. However, no data are currently available regarding the relevance of this mechanism in other CAPS phenotypes.

OBJECTIVE

To evaluate somatic NLRP3 mosaicism as the disease-causing mechanism in patients with clinical CAPS phenotypes other than CINCA and NLRP3 mutation-negative.

METHODS

NLRP3 analyses were performed by Sanger sequencing and by massively parallel sequencing. Apoptosis-associated Speck-like protein containing a CARD (ASC)-dependent nuclear factor kappa-light chain-enhancer of activated B cells (NF-κB) activation and transfection-induced THP-1 cell death assays determined the functional consequences of the detected variants.

RESULTS

A variable degree (5.5-34.9%) of somatic NLRP3 mosaicism was detected in 12.5% of enrolled patients, all of them with a MWS phenotype. Six different missense variants, three novel (p.D303A, p.K355T and p.L411F), were identified. Bioinformatics and functional analyses confirmed that they were disease-causing, gain-of-function NLRP3 mutations. All patients treated with anti-interleukin1 drugs showed long-lasting positive responses.

CONCLUSIONS

We herein show somatic NLRP3 mosaicism underlying MWS, probably representing a shared genetic mechanism in CAPS not restricted to CINCA syndrome. The data here described allowed definitive diagnoses of these patients, which had serious implications for gaining access to anti-interleukin 1 treatments under legal indication and for genetic counselling. The detection of somatic mosaicism is difficult when using conventional methods. Potential candidates should benefit from the use of modern genetic tools.

[CAPS: cryopyrin-associated periodic syndrome]

Cryopyrin-associated periodic syndrome (CAPS) is an autoinflammatory syndrome caused by heterozygous mutations of NLRP3 gene. CAPS consists of three phenotypically similar but distinct syndromes: familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome and CINCA syndrome. Among them, FCAS shows the mildest phenotype while CINCA is the severest. Common symptoms include sporadic or cold-induced nonpruritic urticarial rash and fever. Severe cases suffers from deafness, meningitis, articular contracture and secondary amyloidosis. Gain-of-function mutations of NLRP3 causes excessive production of a potent proinflammatory cytokine IL-1β, thereby evokes autoinflammatory symptoms of CAPS. Recent advances of anti-IL-1 therapy dramatically improved the prognosis of CAPS. Currently three anti-IL-1 medicines are available, and all of them significantly improved clinical symptoms of CAPS patients. Although long-term observation is still needed, the molecular-targeted therapy has opened up a new opportunity for managing CAPS.

Four cases of Muckle-Wells syndrome within the same family

Muckle-Wells syndrome is a rare autosomal dominant disease that belongs to a group of hereditary febrile syndromes. It is characterized by recurrent and self-limited episodes of fever, urticaria, arthralgia, myalgia and conjunctivitis since childhood, which are related to exposure to cold temperatures. Lately, progressive sensorineural hearing loss occurs. Amyloidosis is the main complication and can be found in about 25% of the cases. It has been demonstrated that there is an association with mutations in the NLRP3 gene, which codifies cryopyrin, a protein responsible for regulating the production of proinflammatory cytokines, such as interleukin-1Beta. The authors report four cases of the disease within a family.

Muckle-Wells syndrome/neonatal-onset multisystem inflammatory disease overlap associated with myelodysplasia and cerebrovascular accident

We describe a patient with overlapping clinical features of Muckle-Wells syndrome and neonatal-onset multisystem inflammatory disease with an absence of mutation in exon 3 of the CIAS1 ⁄ PYPAF1 ⁄ NALP3 gene. Myelodysplasia and cerebrovascular accident were additional features in this patient, which to our knowledge have not been previously described in association with these disorders. The urticarial rash, myelodysplasia and raised inflammatory markers responded to treatment with the interleukin-1 receptor antagonist, anakinra.

Mast cells mediate neutrophil recruitment and vascular leakage through the NLRP3 inflammasome in histamine-independent urticaria

Urticarial rash observed in cryopyrin-associated periodic syndrome (CAPS) caused by nucleotide-binding oligomerization domain-leucine-rich repeats containing pyrin domain 3 (NLRP3) mutations is effectively suppressed by anti-interleukin (IL)-1 treatment, suggesting a pathophysiological role of IL-1beta in the skin. However, the cellular mechanisms regulating IL-1beta production in the skin of CAPS patients remain unclear. We identified mast cells (MCs) as the main cell population responsible for IL-1beta production in the skin of CAPS patients. Unlike normal MCs that required stimulation with proinflammatory stimuli for IL-1beta production, resident MCs from CAPS patients constitutively produced IL-1beta. Primary MCs expressed inflammasome components and secreted IL-1beta via NLRP3 and apoptosis-associated speck-like protein containing a caspase recruitment domain when stimulated with microbial stimuli known to activate caspase-1. Furthermore, MCs expressing disease-associated but not wild-type NLRP3 secreted IL-1beta and induced neutrophil migration and vascular leakage, the histological hallmarks of urticarial rash, when transplanted into mouse skin. Our findings implicate MCs as IL-1beta producers in the skin and mediators of histamine-independent urticaria through the NLRP3 inflammasome.

An update on childhood urticaria and angioedema

PURPOSE OF REVIEW

The present review serves to address urticaria - both acute and chronic - as well as the differential diagnosis of urticarial syndromes in the pediatric population. We also wish to update the reader on progress in the pathophysiology, diagnosis and treatment of urticaria.

RECENT FINDINGS

Acute and chronic urticaria represent syndromes caused by a variety of triggers. Recent literature continues to describe subtypes of urticaria that may be differentially responsive to particular therapies. Recent associations highlight the need to fully evaluate patients for allergic and infectious triggers of urticaria. It is important to distinguish idiopathic urticaria from related conditions such as anaphylaxis, systemic conditions and autoimmune urticaria. Although antihistamines remain a cornerstone of therapy, particular urticaria subtypes may also respond to novel therapies such as omalizumab. Chronic urticaria has a significant impact on a patient's quality of life.

SUMMARY

Urticaria is a common condition. Our understanding of distinct urticaria subtypes differentially responsive to targeted therapies continues to increase. Due to the myriad of triggers that may cause urticaria, careful individualized patient assessment is necessary to exclude potential etiologies prior to a diagnosis of idiopathic urticaria.

A case of Muckle-Wells syndrome caused by a novel H312P mutation in NALP3 (cryopyrin)

Here, we report a case of Muckle-Wells syndrome (MWS) caused by a novel mutation in the CIAS1/NALP3 gene. A 23-year-old woman had recurrent self-limited inflammatory episodes from childhood, with headache, abdominal pain, arthritis, and urticarial rash, associated with profound sensorineural hearing loss. The diagnosis was established on the basis of a typical clinical picture together with a missense mutation, which replaced an amino acid adjacent to one in an earlier reported case of MWS resembling this one.

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.

Biological and clinical aspects of Muckle-Wells syndrome

Muckle-Wells syndrome (MWS), as well as familial cold autoinflammatory syndrome (FCAS) and chronic infantile neurological cutaneous and articular syndrome (CINCA), arises from a missense mutation in the CIAS1 gene. Current progress of biology revealed that NALP3, a protein coded by the CIAS1 and expressed in monocytes, recognizes some bacterial products or harmful metabolites invaded in the cytoplasm, and forms inflammasome with other molecules. As a result, caspase-1 is activated leading to cleavage of pro-IL-1beta and extracellular release of IL-1beta. NALP3 of patients with MWS can be spontaneously activated without obvious stimulation, which causes recurrent attacks of inflammatory symptoms characterized by fever, urticarial rash, conjunctivitis and arthritis, and some patients develop amyloidosis. In addition, sensorineural hearing disturbance progresses gradually. Recently, significant efficacy of anakinra, a recombinant IL-1 receptor antagonist, has been demonstrated in treatment of MWS. So far, only a few cases have been reported from Japan, however an accurate diagnosis has to be established for the latent cases who have not received optimum treatment before occurrence of irreversible deafness or renal failure.