Cryopyrin-associated periodic syndrome (CAPS) comprises a group of disorders characterized by recurrent bouts of systemic inflammation related to overactivation of inflammasome. So far, neither large cases of the correlation between genotype and phenotype nor treatment strategies have been clearly stated in China. Here, we studied the clinical and genetic characteristics and their correlation from 30 CAPS patients in China. We identified the pathogenesis for novel mutations by activating NLRP3 inflammasome for peripheral cells with ATP plus LPS, compared characteristics with other case series, and analyzed treatment outcomes of these patients. The patients harbored 19 substitutions in NLRP3, and 8 of them were novel mutations. Among these novel mutations, percentages of severe musculoskeletal, ophthalmologic, and neurological symptoms were higher compared with other case serials. The correlation of phenotypes and their variants seemed different in our cases, such as T350M, S333G/I/R, and F311V (somatic mosaicism). Ten patients received Canakinumab treatment, which proved effective at alleviating musculoskeletal, neurological, auditory, visual manifestations, fever, and rash for 10-20 months follow-up. Patients treated with prednisolone or prednisolone plus thalidomide or methotrexate, tocilizumab, TNF inhibiting agents, and sirolimus achieved only partial remission. Importantly, we firstly identified somatic mosaicism mutation of F311V, which was severe. Our study extended the spectrum of genotype and phenotype and characteristics of their correlations and provided detailed responses to different treatment strategies. These data provide guidance for future diagnosis and management for CAPS.

OBJECTIVE: Nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3-associated autoinflammatory disease (NLRP3-AID) is a rare autosomal dominant systemic autoinflammatory disease. We aimed to summarize the phenotypic and genotypic features of Chinese adult NLRP3-AID patients with hearing loss.
METHODS: A retrospective cohort study of twenty-one adult patients with NLRP3-AID was conducted in Peking Union Medical College Hospital between July 2015 and March 2023. All patients underwent whole exome sequencing and otorhinolaryngologic assessments. Clinical features and therapeutic data were collected and analysed.
RESULTS: We found that 13/21 (61.90%) of patients had hearing loss with high-frequency impairment in the majority, and most patients presented with vestibular dysfunction as a new finding. The NLRP3-AID patients with early-onset, cold or stress triggered episodes, red eyes, fatigue, hypopsia and mutations located in the NACHT domain of the NLRP3 protein were more likely to suffer from hearing loss, especially sensorineural hearing loss, perhaps as a result of pathogenic variants of high penetrance. By a series of audiological evaluations, TNF-α inhibitors were confirmed to improve or reverse hearing loss.
CONCLUSIONS: We reported the first cohort of Chinese adult NLRP3-AID patients with hearing loss and characterized vestibular dysfunction, highlighted the necessity for attention to high-frequency hearing and provided potential alternative treatment.

NOD-like receptor family, pyrin domain-containing 3 (NLRP3) is a central protein contributing to human inflammatory disorders, including cryopyrin-associated periodic syndrome and sepsis. However, the molecular mechanisms and functions of NLRP3 activation in various diseases remain unknown. Here, we generated gain-of-function knock-in mice associated with Muckle-Wells syndromes using the Cre-LoxP system allowing for the constitutive T346M mutation of NLRP3 to be globally expressed in all cells under the control of tamoxifen. The mice were treated with tamoxifen for 4 days before determining their genotype by PCR and sequence analysis. In vitro, we found that bone marrow-derived macrophage from homozygous T346M mutation mice displayed a robust ability to produce IL-1β in response to lipopolysaccharide exposure. Moreover, ASC specks and oligomerization were observed in the homozygous mutant bone marrow-derived macrophages in the presence of lipopolysaccharides alone. Mechanistically, K+ and Ca2+ depletion and mitochondrial depolarization contribute to the hyperactivation of mutant NLRP3. In vivo, homozygous mice carrying the T346M mutation exhibit weight loss and mild inflammation in the resting state. In the lipopolysaccharide-mediated sepsis model, homozygous mutant mice exhibited higher mortality and increased serum circulating cytokine levels, accompanied by serious liver injury. Furthermore, an increase in myeloid cells in the spleen has been suggested to be a risk factor for inducing sepsis sensitivity. Altogether, we describe a cryopyrin-associated syndrome animal model with the T346M mutation of NLRP3 and suggest that the hyperactivated inflammasome aggregated by the mutant NLRP3 lowers the inflammatory response threshold both in vitro and in vivo.

Familial cold autoinflammatory syndrome (FCAS) is the mildest subtype of cryopyrin-associated periodic syndrome (CAPS) and is a rare inherited systemic autoinflammatory disease (SAID). CAPS is the consequence of a rare group of genetic disorders that are mostly reported in European and American populations, but scarcely reported in Chinese populations. NLRP3, NLRP12, PLCG2, and NLRC4 are known pathogenic genes associated with FCAS, and the aim of this study was to identify pathogenic mutations in two intact pedigrees of Chinese FCAS. We performed Sanger sequencing of genomic DNA samples from 25 affected and 32 unaffected members of the two intact pedigrees and analyzed the pathogenic mutations for their conservativeness using multiple sequence alignment tools. In addition, we reviewed previously reported pathogenic genes of FCAS and their pathogenicity classification and summarized the characteristics of different genotypes and phenotypes of FCAS. This study reported two intact FCAS pedigrees with different genotypes and phenotypes, the heterozygous mutation (p.V72M) in NLRP3 in pedigree 1 and the heterozygous mutation (p.R754H) in NLRP12 in pedigree 2. There are no reports targeting p.V72M in NLRP3 in FCAS1, and there are relatively few relevant phenotypic data on the clinical manifestations identified in previous pedigrees. Multiple sequence comparisons of NLRP3 indicate that the p.V72M mutation is highly conserved during evolution. Our study has enriched the understanding of the pathogenesis of FCAS, a rare disease especially in Asian populations. KEY POINTS: •The NLRP3 (p.V72M) variant was first discovered in the Chinese pedigree of FCAS1 •NLRP12 (p.R754H) variants are not conserved in multiple sequence alignments, but they are still co-segregated and expressed in the big Chinese diseased pedigree.

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.

As one of the systemic autoinflammatory diseases (SAIDs), the nucleotide-binding oligomerization domain-like receptor protein (NLRP)12 autoinflammatory disease (NLRP12-AD) is an autosomal dominant disorder associated with NLRP12 mutation. SAIDs have been hardly reported in the Chinese population, and NLRP12-AD has been reported only in Caucasians. We report the first case series of NLRP12-AD in the Chinese population coupled with literature review. Three Han Chinese adult patients with clinical phenotype suggestive of NLRP12-AD carrying NLRP12 variants were treated by the authors in 2015. Their phenotype and genotype were carefully studied. A PubMed search for SAIDs was conducted between January, 1990 and January, 2016, and we focused on NLRP12-AD. All three adult patients developed periodic disease in adulthood. They presented with recurrent fever (n = 3), polyarthralgia (n = 3), myalgia (n = 3), urticaria (n = 2), lymphadenopathy (n = 2), and erythema nodosa (n = 1). All patients carry the NLRP12 mutation F402L. Based upon our analysis of a total of 26 patients with NLRP12-AD in the literature, both familial and sporadic cases were equally reported and late-onset cases accounted for 28 %. NLRP12-AD patients typically present with periodic fever, urticaria-like rash, arthralgia/arthritis, myalgia, and lymphadenopathy. Genotyping identifies the NLRP12 gene mutations, notably F402L (55 %). Relative to the literature reports, our patients had the similar phenotypic and genotypic features. Patients with NLRP12-AD usually respond to glucocorticoid therapy. Our report is the first to confirm the presence of NLRP12-AD in the Chinese population. It highlights the importance of screening NLRP12 in patients with unexplained periodic fever syndrome.