Identification of a variant in NLRP3 gene in a patient with Muckle-Wells syndrome: a case report and review of literature

BACKGROUND

Cryopyrin-associated periodic syndrome (CAPS), a rare genetic autoimmune disease, is composed of familial cold autoinflammatory syndrome (FCAs), Muckle-Wells syndrome (MWS), and neonatal onset multisystem inflammatory disease (NOMID). MWS is caused by dominantly inherited or de novo gain-of-function mutations in the NOD-like receptor 3 (NLRP3) gene. At present, there is no report about the variation of R262W in China.

CASE PRESENTATION

We reported a 3-year-old Chinese boy who had recurrent fever without obvious inducement, bilateral conjunctival congestion, and urticarial-like rash. Laboratory examination showed elevation in leukocyte count, neutrophil count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) and serum amyloid protein (SAA) levels. Whole exome sequencing identified a missense variation c.784-786delinsTGG (p.R262W) in the coding region of the NLRP3 gene.

CONCLUSION

A classical variant of the NLRP3 gene in a patient with MWS was first reported in China.

A 9-Year-Old Patient with Recurrent Fever, Urticarial Rash and Demyelinating Brain Lesions: NLRP3-Autoinflammatory Disease in Ecuador

Autoinflammatory diseases (AIDs) are a relatively new family disorders defined approximately 20 years ago. AIDs are caused by defect(s) or dysregulation of the innate immune system, characterized by recurrent or continuous inflammation and lack of a primary pathogenic role for the adaptive immune system. One AID, NLRP3-associated autoinflammatory disease (NLRP3-AID), involves a clinical presentation since the neonatal period or childhood, with multiple inflammatory recurrent symptoms that appear throughout the patient´s life. We present the first case of NLRP3-AID in Ecuador. The patient presented recurrent fever since 6 months of age associated with urticarial rash, arthralgias, and abdominal pain; recently, he had a seizure at 7 years of age. Brain MRI revealed demyelinating lesions, and genetic testing uncovered a de novo mutation in the NLRP3 gene. The patient had a good clinical response to treatment with canakinumab.

Behçet's Syndrome in a Chinese Pedigree of NLRP3-Associated Autoinflammatory Disease: A Coexistence or Novel Presentation?

Objectives:NLRP3-associated autoinflammatory disease (NLRP3-AID) and Behçet's syndrome (BS) both belong to autoinflammatory diseases and rarely co-occur. Here we reported a Chinese pedigree of NLRP3-AID presented with BS.

Methods: We recorded a Chinese pedigree of NLRP3-AID presented with BS. Whole-exome sequencing was performed to find the hereditary susceptibility gene, and Sanger sequencing was performed on a consecutive cohort of 30 BS patients. We also reviewed the English literature on vasculitis associated with NLRP3-AID.

Results: The proband was a 45-year-old Chinese Han woman. She and her 12-year-old daughter presented with recurrent fevers, cold-induced urticaria, oral, and genital ulcers, conjunctivitis, uveitis, optic atrophy, erythema nodosum, headache, and hearing loss. They were initially suspected of having BS, and both responded poorly to corticosteroids and immunosuppressants, while anti-TNF therapy was moderately effective. Pedigree analysis revealed another four relatives with similar symptoms, and a heterozygous NLRP3 gene mutation c.1316C>T, p.Ala439Val was identified by whole-exome sequencing and Sanger sequencing. However, we did not discover NLRP3 gene mutation by Sanger sequencing in a confirmative cohort of 30 BS cases. A few case reports of vasculitis coexisting with NLRP3-AID, including a case of glomerulonephritis, and five cases of retinal vasculitis, were summarized through literature review.

Conclusions: Our study is the first report of NLRP3-AID associated with BS. The coexistence of NLRP3-AID and BS reveals the extensive heterogeneity of the pathogenesis of systemic autoinflammatory diseases and calls for specific therapeutics.

Cold urticaria - What we know and what we do not know

Cold urticaria (ColdU) is a common form of chronic inducible urticaria characterized by the development of wheals, angioedema or both in response to cold exposure. Recent research and guideline updates have advanced our understanding and management of ColdU. Today, its pathophysiology is thought to involve the cold-induced formation of autoallergens and IgE to these autoallergens, which provoke a release of proinflammatory mediators from skin mast cells. The classification of ColdU includes typical and atypical subtypes. We know that cold-induced wheals usually develop on rewarming and resolve within an hour and that anaphylaxis can occur. The diagnosis relies on the patient's history and cold stimulation testing. Additional diagnostic work-up, including a search for underlying infections, should only be done if indicated by the patient's history. The management of ColdU includes cold avoidance, the regular use of nonsedating antihistamines and the off-label use of omalizumab. However, many questions regarding ColdU remain unanswered. Here, we review what is known about ColdU, and we present important unanswered questions on the epidemiology, underlying pathomechanisms, clinical heterogeneity and treatment outcomes. Our aim is to guide future efforts that will close these knowledge gaps and advance the management of ColdU.

Hemolysis and Neurologic Impairment in PAMI Syndrome: Novel Characteristics of an Elusive Disease

PSTPIP1-associated myeloid-related proteinemia inflammatory (PAMI) syndrome is a rare early-onset autoinflammatory disease associated with various hematologic findings, including chronic neutropenia and pancytopenia. We report a unique case of PAMI syndrome in a toddler with transfusion-dependent hemolytic anemia, hepatosplenomegaly, failure to thrive, developmental delay, and multiple malformations. Because of acute inflammatory-driven decompensation, anakinra was started with dramatic improvement of both the hematologic and neurologic involvement. A customized next-generation sequencing panel later identified a de novo pathogenic variant in the PSTPIP1 gene, confirming the diagnosis. Our case illustrates the broad spectrum of phenotypes associated with PAMI syndrome, which should be considered in any case of unexplained cytopenias associated with autoinflammatory stigmata. It is also one of the few reports of neurologic involvement in PSTPIP1-associated inflammatory diseases. Increased awareness of this rare disease and early performance of genetic testing can correctly diagnose PAMI syndrome and prevent disease complications.

CRYOPYRIN-ASSOCIATED PERIODIC SYNDROME-ASSOCIATED UVEITIS AND PAPILLITIS

PURPOSE

To report a case of uveitis and papillitis in a patient with cryopyrin-associated periodic syndrome.

METHODS

Case report. A 44-year-old white woman with a long history of inflammatory arthritis, diffuse erythematous rashes and hives, and hearing loss was referred to the Massachusetts Eye Research and Surgery Institution for an evaluation of chronic ocular inflammation. She was diagnosed with bilateral papillitis and uveitis after a comprehensive eye examination, which included dilated fundoscopy, optic nerve ocular coherence tomography, fluorescein angiography, indocyanine green angiography, and B-scan ultrasonography. She was later diagnosed with cryopyrin-associated periodic syndrome, an interleukin-1-driven autoimmune disease, as confirmed by genetic testing. Soon after starting treatment with anakinra, a human interleukin-1 receptor antagonist, she experienced rapid improvement of her ocular and systemic symptoms, including rash, uveitis, and arthritis.

RESULTS

Cryopyrin-associated periodic syndrome-associated ocular inflammation in remission with anakinra 100-mg daily subcutaneous injection.

CONCLUSION

Anakinra is a very effective treatment for both cryopyrin-associated periodic syndrome and cryopyrin-associated periodic syndrome-associated ocular inflammation.

Autoinflammatory diseases: State of the art

Autoinflammatory diseases are characterized by innate immunity abnormalities. In autoinflammatory diseases (AID), inflammatory blood biomarkers are elevated during crisis without infection and usually without autoantibodies. The first 4 described AID were familial Mediterranean fever, cryopyrin-associated periodic fever syndrome (CAPS) or NLRP3-associated autoinflammatory disease (NRLP3-AID), mevalonate kinase deficiency (MKD) and TNFRSF1A-receptor associated periodic fever syndrome (TRAPS). Since their description 20 years ago, and with the progresses of genetic analysis, many new diseases have been discovered; some with recurrent fever, others with predominant cutaneous symptoms or even immune deficiency. After describing the 4 historical recurrent fevers, some polygenic inflammatory diseases will also be shortly described such as Still disease and periodic fever with adenitis, pharyngitis and aphtous (PFAPA) syndrome. To better explore AID, some key anamnesis features are crucial such as the family tree, the age at onset, crisis length and organs involved in the clinical symptoms. An acute phase response is mandatory in crisis.

New autoinflammatory diseases

PURPOSE OF REVIEW

Advances in sequencing techniques and systematic cohort-analysis of patients with autoinflammatory phenotypes have enabled a burst in the recognition of new autoinflammatory diseases and contributed to the description of the mechanisms involved in autoinflammation. This review focuses on new genetic and mechanistic discoveries that have broadened the definition of autoinflammatory diseases in the context of the established landscape, providing new therapeutic opportunities and avenues for further discoveries.

RECENT FINDINGS

Mechanistic insights of inflammatory diseases open opportunities for new targeted therapies. Advances in high-throughput screening of small-molecule inhibitors accelerate the discovery of new and more specific therapeutic options. Recent evidence establishes IL-18 as a driver of macrophage activation, emerging as a new biomarker and therapeutic target. Finally, the identification of escape of nonsense-mediated decay as the genetic mechanism resulting in a monogenic immune-dysregulatory disease, unveils a possibility for future discoveries.

SUMMARY

Recent mechanistic findings in autoinflammatory diseases as well as the identification of specific biomarkers and discovery of new diseases, continue to pave the way for ever more specific targeted approaches. These therapies are not only applicable to monogenic autoinflammatory syndromes but also for other diseases in which the same pathways are dysregulated.

[Clinical overview of auto-inflammatory diseases]

Monogenic auto-inflammatory diseases are characterized by genetic abnormalities coding for proteins involved in innate immunity. They were initially described in mirror with auto-immune diseases because of the absence of circulating autoantibodies. Their main feature is the presence of peripheral blood inflammation in crisis without infection. The best-known auto-inflammatory diseases are mediated by interleukines that consisted in the 4 following diseases familial Mediterranean fever, cryopyrinopathies, TNFRSF1A-related intermittent fever, and mevalonate kinase deficiency. Since 10 years, many other diseases have been discovered, especially thanks to the progress in genetics. In this review, we propose the actual panorama of the main known auto-inflammatory diseases. Some of them are recurrent fevers with crisis and remission; some others evaluate more chronically; some are associated with immunodeficiency. From a physiopathological point of view, we can separate diseases mediated by interleukine-1 and diseases mediated by interferon. Then some polygenic inflammatory diseases will be shortly described: Still disease, Schnitzler syndrome, aseptic abscesses syndrome. The diagnosis of auto-inflammatory disease is largely based on anamnesis, the presence of peripheral inflammation during attacks and genetic analysis, which are more and more performant.

Future Prospects of Biologic Therapies for Immunologic Diseases

This article presents an overview of future uses for biologic therapies in the treatment of immunologic and allergic conditions. Discussion is centered on the use of existing therapies outside of their current indication or on new therapies that are close to approval. This information may help familiarize practicing allergists and immunologists with therapies they may soon encounter in their practice as well as help identify conditions and treatments that will require further study in the near future.

Gene mutations and clinical phenotypes in 15 Chinese children with cryopyrin-associated periodic syndrome (CAPS)

The aim of our study is to explore the features of clinical manifestations and genetic mutations in Chinese CAPS patients. Fifteen confirmed patients with CAPS were enrolled. The onset time ranges from 2 days after birth to 6 years and 1 month. Recurrent urticaria rash (93.3%) with fever (100%) were two dominant characteristics of these patients that were presented as either acute or chronic process. Systemic involvements were found in all patients except for one with only rash and fever. The top three symptoms were fever (100%), rash (93.3%) and myalgia (76%). Other clinical manifestations include arthritis (11 cases), lung involvement (seven cases), optical dysfunction (seven cases), nerve deafness (six cases), nervous system involvement (five cases), hepatomegaly, splenomegaly and lymphadenectasis (five cases). Also, four patients had heart involvement and one patient suffered kidney involvement. The laboratory inflammation index such as leukocyte counts, platelet counts, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), serum amyloid A (SAA) and fibrinogen (FIB) increased significantly at initial stage, but decreased after therapy. As for gene mutation detection, Twelve out of 15 patients were confirmed with mutation in NLRP3, including 11 mutant site: c1789A<G, c.1703T<A, c.913G<A, c.1710G<C, c.1057G<T, c.2335C<T, c.932TvC, c.296G<C, c.663C<T, t.1702T<A, 299G<A. Mutation sites c.1703T<A, c.2335C<T, c.296G<C, c.663C<T, and 299G<A were newly identified. The association between gene mutation and clinical manifestation shows that D305N was highly associated with severe organs involvements, and therefore, the time of therapy and regimen were critical for the prognosis of disease. As the largest cohort study of Chinese CAPS patients, we confirmed that all patients presented typical clinical manifestations, identified five new mutation sites on NLRP3 and analyzed the correlation between the genotypes and phenotypes. We also raise concerns for one case with serious conditions that only had two nonsense mutations (c.663C<T and t.1702T<A) detected.

New mosaic tiles in childhood hereditary autoinflammatory disorders

The protean clinical phenotypes of hereditary autoinflammatory disorders (HAID) are caused by abnormal activation of innate immunity and consist of seemingly unprovoked inflammatory flares localized to multiple organs, such as the skin, joints, serosal membranes, gut, and central nervous system. Different mutations in genes implied in activation of the interleukin-1 (IL-1)-structured inflammasome, cytoskeletal signaling and apoptosis contribute to the pathogenesis of different HAID, which mostly start in childhood with self-limited flares unrelated to infectious agents, autoantibody production or autoreactive cells. Though IL-1 remains pivotal in many inflammasome-mediated diseases, other cytokinopathies involving IL-18, nuclear factorκ-B, interferons, and tumor necrosis factor have provided new horizons in the definition of HAID of children: the list of HAID has expanded as a consequence of a better understanding of their pathogenetic molecular mechanisms and also application of new genetic technologies. However, diagnosis of most HAID is clinical and focused on several evidence-based criteria sets: their discrimination remains challenging for unexperienced pediatricians as there are no universally accepted algorithms, and a still relevant number of patients may linger without any clarifying genetic analysis, whose interpretation combined with processing of treatment options should be discussed on a multidisciplinary basis.

[Cryopyrin-associated periodic syndromes]

Cryopyrin-associated periodic syndromes (CAPS) are linked to one single gene mutations, however they are associated with 3 syndromes, which are, from the mildest to the most severe phenotype familial cold urticaria, Muckle-Wells syndrome and chronic, infantile, neurologic, cutaneous, articular (CINCA) syndrome also called neonatal-onset multisystem inflammatory disease (NOMID). Autosomic dominant inheritance is present in most cases but in CINCA/NOMID syndrome where neomutations are more common. Mutations in the gene encoding cryopyrin, NLRP3, are associated with deregulation of caspase-1 activity, excessive interleukin-1 production and an autoinflammatory syndrome, which in familial cold urticaria and Muckle-Wells syndrome may be triggered or worsened by exposure to coldness. More and more mutations are described and even somatic mutations that can explain some clinical signs beginning in adulthood. Patients disclose a pseudo-urticarial rash, arthralgia, headaches, sometimes fever, biological inflammation but also, in severe forms of the disease, neurologic inflammation with central deafness, ophthalmologic inflammation, chronic meningitis. Some CINCA/NOMID patients also develop growth cartilage pseudo-tumoral hypertrophy. Natural disease history is usually benign in familial cold urticarial but severe in the other forms, particularly regarding neuro-sensorial involvement. In addition, secondary AA amyloidosis may develop in all forms in the absence of control of chronic inflammation. Anti-interleukin-1 treatment with anakinra, rilonacept or canakinumab induces in most cases complete remission, however sequelae may be present, particularly if central deafness or cartilage bone hypertrophy have already developed. This treatment is also important to prevent secondary amyloidosis or stabilize and even sometimes allow improvement of amyloidosis lesions.

Real-World Experience and Impact of Canakinumab in Cryopyrin-Associated Periodic Syndrome: Results From a French Observational Study

OBJECTIVE

The ENVOL study was designed to assess the psychosocial impact of disease and therapy in a French cohort of cryopyrin-associated periodic syndromes (CAPS) patients (and caregivers) treated with canakinumab.

METHODS

The ENVOL study was a multicenter, observational study of CAPS patients given ≥1 canakinumab dose. Data were collected before treatment, at 6 and 12 months afterward, and at the last visit. Patients and caregivers completed questionnaires assessing changes from the 12 months of pretreatment to 12 months prior to interview. Data were analyzed retrospectively.

RESULTS

The study included 10 physicians and 68 patients (53 adults, 15 children). Sixty-five patients (95.6%) were still receiving canakinumab at the last visit (median 5 years after starting therapy). The mean ± SD score for patient-reported general health increased from 7 ± 2.9 before canakinumab to 2.7 ± 2.7 after treatment (P < 0.001). Physical and emotional symptoms resolved or improved in a substantial proportion of patients, including bodily pain (38 of 46 patients), fever (32 of 39), skin disease (35 of 41), fatigue (31 of 47), self-confidence (29 of 46), and energy (34 of 47). Social activity, relationships, sexuality, and energy measures improved in >40% of respondents. Caregivers spent a median of 3 versus 0.5 hours/week on care in the 12 months of pretreatment versus 12 months prior to interview (P < 0.001). Following treatment, patients required fewer consultations with general practitioners (mean ± SD per patient per year: 5.2 ± 7.4 versus 8.5 ± 7.2 pretreatment), internists/rheumatologists/dermatologists (2.0 ± 2.1 versus 3.7 ± 3.9), and pediatricians (1.8 ± 1.5 versus 4.4 ± 4.2).

CONCLUSION

Long-term treatment with canakinumab achieves a highly relevant improvement in the physical, emotional, and social lives of patients with CAPS, accompanied by a marked reduction in support required from caregivers and in health care consultations.

Muckle-Wells syndrome in Chinese patients: a single center case series

Muckle-Wells syndrome (MWS) is a rare autoinflammatory disease. This study aimed to report the clinical features and gene variations of the first case series of MWS patients in Chinese population. Four Han Chinese patients were diagnosed with MWS and followed up at our adult clinic for autoinflammatory diseases. All relevant phenotypes and genotypes were collected. All patients were adult male. The median age of disease onset was 4.5 years, and one patient had adult-onset disease. No positive family history was observed. All patients had a remittent disease course. The duration of fever attacks ranged from 0.5 to 7 days. Skin rashes were present in all patients. The other manifestations included polyarthralgia/arthritis (n = 3), oral ulcers (n = 2), conjunctivitis (n = 2), myalgia (n = 2), headache (n = 2), pharyngitis (n = 1), abdominal pain (n = 1), severe sensorineural hearing loss (n = 1), and chronic meningitis with communicating hydrocephalus (n = 1). None of the patients showed evidence of renal amyloidosis. Each patient carried a heterozygous mutation in an NLRP3 gene, including D29V, V70M, T348M, and Q703K, respectively. D29V and V70M variants were novel mutations in exon 1 of NLRP3. All patients had good response to corticosteroids. Our study suggests that MWS could be identified in Chinese population. Our finding of novel mutations in NLRP3 may expand the diversity of MWS.

The diagnostic yield of whole-exome sequencing targeting a gene panel for hearing impairment in The Netherlands

Hearing impairment (HI) is genetically heterogeneous which hampers genetic counseling and molecular diagnosis. Testing of several single HI-related genes is laborious and expensive. In this study, we evaluate the diagnostic utility of whole-exome sequencing (WES) targeting a panel of HI-related genes. Two hundred index patients, mostly of Dutch origin, with presumed hereditary HI underwent WES followed by targeted analysis of an HI gene panel of 120 genes. We found causative variants underlying the HI in 67 of 200 patients (33.5%). Eight of these patients have a large homozygous deletion involving STRC, OTOA or USH2A, which could only be identified by copy number variation detection. Variants of uncertain significance were found in 10 patients (5.0%). In the remaining 123 cases, no potentially causative variants were detected (61.5%). In our patient cohort, causative variants in GJB2, USH2A, MYO15A and STRC, and in MYO6 were the leading causes for autosomal recessive and dominant HI, respectively. Segregation analysis and functional analyses of variants of uncertain significance will probably further increase the diagnostic yield of WES.

Chronic Infantile Neurological Cutaneous and Articular (CINCA) syndrome: a review

Introduction

The Chronic Infantile Neurological Cutaneous and Articular (CINCA, or Neonatal-onset multisystem inflammatory disease NOMID) is a rare autoinflammatory disease identified in 1987 by Prieur et al., typically characterized by the triad of skin rash, arthropathy and central nervous system manifestations. It represents the most severe phenotype of the cryopyrin-associated periodic syndrome (CAPS).

Clinical description and etiology

The syndrome is due to autosomal dominant gain of function mutations in NLRP3, which encodes a key component of the innate immunity that regulates the activation and secretion of interleukin (IL)-1β. From the first days of life, patients display an urticarial rash in association with chronic inflammation with a typical facies featured by frontal bossing and saddle back nose. The CNS manifestations include chronic aseptic meningitis leading to brain atrophy, mental delay and sensorineural hearing loss. Chronic polyarthritis and alteration of the growth cartilage also may be present. CINCA/NOMID diagnosis is made clinically, based on the presence of characteristic features. The detection of NLRP3 mutations is diagnostic in 65–70% of cases. Indeed, up to 40% of affected patients are negative for germline NLRP3 mutations and several subjects are carriers of somatic mosaicism. Due to the pivotal role of Cryopyrin in the control of Caspase-1 activation and the massive secretion of active IL-1β observed in cryopyrin-mutated individuals, anti-IL1 treatment represents the standard therapy.

Conclusion

Prognosis of CINCA/NOMID syndrome has been changed by the availability of anti-IL1 drugs. Nowadays, the use of anti-IL-1 drugs has sensibly reduced the risk of developing main complications such as severe intellectual disability, hearing-loss and amyloidosis, if treatment is started early on.