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

The phenotype and genotype of Chinese adult patients with NLRP3-associated autoinflammatory disease

OBJECTIVES

NLRP3-associated autoinflammatory disease (NLRP3-AID) is a spectrum of autosomal dominant inherited diseases associated with NLRP3 gene mutations. Reports of Chinese NLRP3-AID cases are limited to date. In the present study, we aim to describe the phenotype and genotype of a cohort of Chinese adult NLRP3-AID patients METHODS: This single-center study included sixteen adult patients diagnosed with NLRP3-AID at Department of Rheumatology, Peking Union Medical College Hospital from April 2015 to September 2021. Whole-exome sequencing using next-generation sequencing was performed in each patient. Clinical data and mutational information were compared with a European cohort.

RESULTS

The median age of disease onset was 16 (0-46) years old, and adult-onset was observed in 4 patients (25%). The median time of diagnosis delay was 20 (0-39) years. Five patients (31.3%) had family history of similar symptoms. The most common clinical manifestations were recurrent fever (93.8%), arthralgia/arthritis (81.3%), skin rash (75%), myalgia (62.5%), and central nervous system manifestations (50%). Heterozygous NLRP3 variants detected in these patients were p.T348M (n = 4, 25%), Q703K, V70M, K129R, M116I, P38S, V442I, D303G, G326E, A439V, K829T, L632F and V198M (n = 1, separately). All the variants were missense mutations.

CONCLUSIONS

We reported the largest case series of Chinese adult NLRP3-AID patients. The distinct symptoms of NLRP3-AID patients suggest the heterogeneity of disease. P38S, M116I, K129R, V442I and K829T were identified as novel NLRP3 variants. These data expand the clinical phenotypic and genotypic profiles of NLRP3-AID. Key Points • We characterized the clinical and genetic features of sixteen Chinese adult NLRP3-AID patients. • Thirteen NLRP3 gene variants were confirmed in this cohort, and P38S, M116I, K129R, V442I and K829T were identified as novel variants. • Clinical data and mutation information were compared with a European cohort. • We hope these data would expand the phenotypic and genotypic profile of NLRP3-AID and raise the awareness of early diagnosis and accurate treatment among rheumatologists.

Differential Binding of NLRP3 to non-oxidized and Ox-mtDNA mediates NLRP3 Inflammasome Activation

The NLRP3 inflammasome is a key mediator of the innate immune response to sterile tissue injury and is involved in many chronic and acute diseases. Physically and chemically diverse agents activate the NLRP3 inflammasome. Here, we show that NLRP3 binds non-oxidized and Ox-mtDNA differentially, with a half maximum inhibitory concentration (IC50) for non-oxidized and Ox-mtDNA of 4 nM and 247.2 nM, respectively. The NLRP3 Neonatal-Onset Multisystem Inflammatory Disease (NOMIDFCAS) gain of function mutant could bind non-oxidized mtDNA but had higher affinity for Ox-mtDNA compared to WT with an IC50 of 8.1 nM. NLRP3 lacking the pyrin domain can bind both oxidized and non-oxidized mtDNA. Isolated pyrin domain prefers Ox-mtDNA. The NLRP3 pyrin domain shares a protein fold with DNA glycosylases and generate a model for DNA binding based on the structure and sequence alignment to Clostridium acetobutylicum and human OGG1, an inhibitor of Ox-mtDNA generation, 8-oxoguanine DNA glycosylases. We provide a new model for how NLRP3 interacts with Ox-mtDNA supported by DNA binding in the presence of a monoclonal antibody against the pyrin domain. These results give new insights into the mechanism of inflammasome assembly, and into the function of reactive oxygen species in establishing a robust immune response.

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.

Monogenic Adult-Onset Inborn Errors of Immunity

Inborn errors of immunity (IEI) are a heterogenous group of disorders driven by genetic defects that functionally impact the development and/or function of the innate and/or adaptive immune system. The majority of these disorders are thought to have polygenic background. However, the use of next-generation sequencing in patients with IEI has led to an increasing identification of monogenic causes, unravelling the exact pathophysiology of the disease and allowing the development of more targeted treatments. Monogenic IEI are not only seen in a pediatric population but also in adulthood, either due to the lack of awareness preventing childhood diagnosis or due to a delayed onset where (epi)genetic or environmental factors can play a role. In this review, we discuss the mechanisms accounting for adult-onset presentations and provide an overview of monogenic causes associated with adult-onset IEI.

Cutaneous Manifestations of Autoinflammatory Diseases

Autoinflammatory diseases (AIDs) are a heterogeneous group of disorders in which recurrent or continuous aseptic inflammation arises primarily through antigen-independent hyperactivation of the innate immune system. The skin is frequently involved with a wide variety of cutaneous manifestations, most of which are non-specific. Recognition of skin lesions in AIDs may sometimes provide clues for a correct diagnosis. In this review, the cutaneous involvements of >20 selected AIDs were summarized and organized into different categories based on their characteristic manifestations, such as urticarial dermatosis, neutrophilic dermatosis, granulomatosis, chilblain, lipodystrophy, and hyperkeratosis. With this classification scheme, cutaneous manifestations in AIDs could be more easily identified to facilitate diagnosis in clinical practice.

Clinical benefits of TNF-α inhibitors in Chinese adult patients with NLRP3-associated autoinflammatory disease

BACKGROUND

Nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3)-associated autoinflammatory disease (NLRP3-AID) is a rare, heterogeneous disease entity associated with mutations in NLRP3. Biologic therapy for NLRP3-AID yields diverse results.

OBJECTIVES

We aimed to evaluate the clinical features and outcomes of Chinese adult patients with NLRP3-AID who were treated with tumour necrosis factor (TNF)-α inhibitors.

METHODS

Five patients with NLRP3-AID were diagnosed and treated with TNF-α inhibitors at Peking Union Medical College Hospital between 2017 and 2020 and were followed up for 6 to 12 months. All patients were systematically studied for treatment outcomes, including clinical manifestations and inflammatory markers.

RESULTS

All five adult NLRP3-AID patients were Chinese Han, and four patients were males. The mean age at disease onset was 4.2 ± 4.1 years, and the mean time of diagnosis delay was 19.8 ± 6 years. All patients received TNF-α inhibitors with or without methotrexate/prednisone. During follow-up, all patients achieved remarkable clinical remission of skin lesions and polyarthritis and showed improvements in acute-phase reactants, inflammatory cytokines, patient visual analogue scale, physician global assessment and 36-item Short Form (SF-36).

CONCLUSIONS

Early diagnosis and effective therapy for NLRP3-AID are essential for avoiding irreversible organ damage. TNF-α inhibitors might serve as a therapeutic alternative for patients with NLRP3-AID who have unsatisfactory responses or no access to interleukin-1 inhibitors.

Ocular involvement in monogenic autoinflammatory disease

OBJECTIVE

Monogenic Autoinflammatory diseases (AIDs) are a broad spectrum of rare hereditary diseases whose ocular involvement has not been well characterized yet. This systematic review aims to provide an overview of the current knowledge about ocular findings in AIDs.

METHODS

A systematic literature review was conducted using 2 electronic databases, according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A combination of AIDs and ophthalmology-related search terms were used. All articles were screened by 2 independent reviewers for title, abstract and full text level. We included solely studies that investigated ocular findings in AIDs.

RESULTS

198 papers of 4268 records were retained. Data about 1353 patients with a diagnosis of autoinflammatory disease and ocular involvement were collected (680 CAPS, 211 FMF, 138 TRAPS, 238 Blau, 32 MKD, 21 SIFD, 7 Aicardi Goutières, 3 CANDLE, 8 DADA2, 9 HA20, 6 APLAID). Conjunctivitis was significantly more frequent in CAPS (p < 0.00001), uveitis in Blau, MKD, HA20 and CANDLE (p < 0.00001), papillitis/papilledema in CAPS (p < 0.00001), optic neuritis in Aicardi and DADA2 (p < 0.008), retinal vasculitis in FMF (p < 0.00001), progressive reduction in choroidal thickness in FMF and DADA2 (p < 0.00001), periorbital oedema in TRAPS (p < 0.00001) and retinitis in SIFD (p < 0.00001). Among AIDs with uveitis, granulomatous inflammation was more common in Blau syndrome (p < 0.00001).

CONCLUSION

This systematic literature review characterized the ocular involvement of several AIDs, and the present data may encourage to consider a timely ophthalmological screening program for these rare diseases.

Ocular manifestations in Chinese adult patients with NLRP3-associated autoinflammatory disease

NLRP3-associated autoinflammatory disease (NLRP3-AID) is a rare autosomal dominant disorder involving multiple systems. We aim to assess the ocular manifestations of Chinese adult patients with NLRP3-AID. Twelve adult patients (> 18 years old) were diagnosed as NLRP3-AID at the Department of Rheumatology, Peking Union Medical College Hospital. All patients underwent ophthalmologic evaluation by an ophthalmologist. Clinical and genetic features of these patients were collected and compared with those from Caucasian population. A total of 7 NLRP3-AID patients (58%) 14 eyes had ocular manifestations. Five NLRP3 variants were identified, and 3 patients (43%) with severe ocular damages were all found to have the NLRP3 T348M variant. The incidences of papilledema and optic atrophy in the Chinese adult NLRP3-AID patients of moderate type were similar to those in the Caucasian NLRP3-AID patients of severe type. This is the first cohort of Chinese adult NLRP3-AID patients with ocular involvement. Ocular manifestations were diverse and even severe in NLRP3-AID, particularly in patients with the moderate phenotype, and may have relationship with genotypes. Awareness of these manifestations by rheumatologists and ophthalmologists could help to avoid the irreversible ocular damages.

Computational Modeling of NLRP3 Identifies Enhanced ATP Binding and Multimerization in Cryopyrin-Associated Periodic Syndromes

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.

Neurological manifestations of autoinflammatory diseases in Chinese adult patients

OBJECTIVE

Systemic autoinflammatory diseases (SAIDs) are a group of disorders characterized by a dysregulation of innate immune system leading to multi-systemic inflammation. We aim to assess the neurological manifestations of Chinese adult patients with SAIDs.

METHODS

Eighty adult patients (≥16 years) were diagnosed as SAIDs from April 2015 to June 2019, at the center of adult autoinflammatory diseases, Department of Rheumatology, Peking Union Medical College Hospital. Clinical and genetic features of these patients were collected. All patients underwent neurologic, ophthalmologic and otolaryngologic evaluation.

RESULTS

Totally 31 out of 80 (38.8%) patients had neurological manifestations, including 14 familial Mediterranean fever (45.2%), 6 NLRP3-associated autoinflammatory disease (19.4%), 5 tumor necrosis factor receptor-associated periodic fever syndrome (16.1%), 5 NLRP12-associated autoinflammatory disease (16.1%), and 1 Yao syndrome (3.2%). Twenty patients (64.5%) were adult-onset. The median time of diagnosis delay was 11.7 years (0.5-50 years). The common neurological damage included headache (28 patients, 90.3%), sensorineural hearing loss (6, 19.4%), dizziness (4, 12.9%), cerebral infarction/hemorrhage (4, 12.9%), chronic aseptic meningitis (3, 9.7%), intracranial hypertension (3, 9.7%), papilledema (3, 9.7%), optic neuritis (2, 6.5%), and hydrocephalus (1, 3.2%). Severe neurological damage was observed in 8 patients (25.8%), including brain atrophy, hydrocephalus, complete hearing loss, chronic aseptic meningitis and optic neuritis.

CONCLUSION

Neurological damage was diverse in SAIDs patients. Neurological symptoms should be fully realized by physicians, in not only pediatric but also adult patients with SAIDs. CSF analysis and brain images should be performed promptly. Early diagnosis and appropriate treatment are essential to avoid irreversible neurological complications.

Clinical and genetic features of Chinese adult patients with tumour necrosis factor receptor-associated periodic fever syndrome

Objectives

TNF receptor-associated periodic fever syndrome (TRAPS) is an autosomal dominant systemic autoinflammatory disease caused by mutations of TNF receptor superfamily member 1 A (TNFRSF1A) gene. TRAPS has hardly been reported in the Chinese population. We aimed to characterize the clinical and genetic features of Chinese adult patients with TRAPS.

Methods

Nine adult patients (≥16 years) were diagnosed during April 2015 to June 2019, at the Department of Rheumatology, Peking Union Medical College Hospital. Clinical and genetic features of these patients were evaluated and compared with those from Japan and Europe.

Results

The median age of disease onset was 3 (0.5–38.5) years old, and adult-onset was observed in two (22.2%) patients. The median time of diagnosis delay was 16.5 (1.5–50.5) years. One patient had a family history of TRAPS. The frequent symptoms were fever (nine, 100%), rash (seven, 77.8%), arthralgia/arthritis (five, 55.6%) and abdominal pain (five, 55.6%). Only two (22.2%) patients had periorbital oedema. Nine TNFRSF1A gene variants were detected, including C58R, G65E, F89L, C99G, V202G, V202D, c.769-23T&gt;C, S290I and c.*64T&gt;C. Rash was more frequently seen in Chinese than in Japanese and European patients, while chest pain and amyloidosis occurred less frequently.

Conclusion

This is the first and largest case series of TRAPS in Chinese adult patients. Two novel TNFRSF1A variants, S290I and V202G, have been identified. The different clinical manifestations of our patients compared with those from Japan and Europe might be related to their TNFRSF1A variants.

Development and Validation of a Targeted Next-Generation Sequencing Gene Panel for Children With Neuroinflammation

IMPORTANCE

Neuroinflammatory disorders are a range of severe neurological disorders causing brain and spinal inflammation and are now increasingly recognized in the pediatric population. They are often characterized by marked genotypic and phenotypic heterogeneity, complicating diagnostic work in clinical practice and molecular diagnosis.

OBJECTIVE

To develop and evaluate a next-generation sequencing panel targeting genes causing neuroinflammation or mimicking neuroinflammation.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study in which a total of 257 genes associated with monogenic neuroinflammation and/or cerebral vasculopathy, including monogenic noninflammatory diseases mimicking these entities, were selected. A customized enrichment capture array, the neuroinflammation gene panel (NIP), was created. Targeted high-coverage sequencing was applied to DNA samples taken from eligible patients referred to Great Ormond Street Hospital in London, United Kingdom, between January 1, 2017, and January 30, 2019, because of onset of disease early in life, family history, and/or complex neuroinflammatory phenotypes.

MAIN OUTCOMES AND MEASURES

The main outcome was the percentage of individuals with definitive molecular diagnoses, variant classification, and clinical phenotyping of patients with pathogenic variants identified using the NIP panel. The NIP panel was initially validated in 16 patients with known genetic diagnoses.

RESULTS

The NIP was both sensitive (95%) and specific (100%) for detection of known mutations, including gene deletions, copy number variants, small insertions and deletions, and somatic mosaicism with allele fraction as low as 3%. Prospective testing of 60 patients (30 [50%] male; median [range] age, 9.8 [0.8-20] years) presenting with heterogeneous neuroinflammatory phenotypes revealed at least 1 class 5 (clearly pathogenic) variant in 9 of 60 patients (15%); 18 of 60 patients (30%) had at least 1 class 4 (likely pathogenic) variant. Overall, a definitive molecular diagnosis was established in 12 of 60 patients (20%).

CONCLUSIONS AND RELEVANCE

The NIP was associated with molecular diagnosis in this cohort and complemented routine laboratory and radiological workup of patients with neuroinflammation. Unexpected genotype-phenotype associations in patients with pathogenic variants deviating from the classic phenotype were identified. Obtaining an accurate molecular diagnosis in a timely fashion informed patient management, including successful targeted treatment in some instances and early institution of hematopoietic stem cell transplantation in others.

[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.