Cracking the NLRP3 code: Pioneering precision medicine for inflammation

Precisely diagnosing and effectively treating cryopyrin-associated periodic syndrome (CAPS), an inflammatory condition linked to gain-of-function NLRP3 inflammasome mutations, poses challenges. A novel classification approach may help inform therapeutic decisions and offer valuable insights into broader inflammatory conditions (Cosson et al. J. Exp. Med. 2024. https://doi.org/10.1084/jem.20231200).

The clinicopathologic and immunohistochemical features of 60 cutaneous glomus tumor: a retrospective case series study

BACKGROUND

Glomus Tumor (GT) are benign neoplasms that originate from mesenchymal cells. It presents as tenderness and cold allodynia in the digits, especially in the subungual region. There are a few studies that investigated the mechanism of pain.

OBJECTIVES

To analyze the clinical-pathologic characteristics of GT and to identify the expression of IL-1β, IL-6, and CGRP in it, further, to explore the possible mechanism of pain.

METHODS

The clinical and pathological data of 60 GT patients were retrospectively analyzed. Tissue microarrays and immunohistochemistry were used to measure the expression of IL-1β, IL-6 and CGRP.

RESULTS

GT is more common in females and the ratio of male to was near to 1:2, mostly in middle-aged people. It often occurs in fingertips, especially the thumbs. Patients often present with spontaneous pain, tenderness, and cold hypersensitivity. Both the two pain mediators IL-1β and IL-6 were highly expressed in GT cells of patients with and without cold hypersensitivity. While CGRP was not expressed in GT.

STUDY LIMITATIONS

Low sample size and further research is needed to explore the specific mechanism.

CONCLUSIONS

IL-1β and IL-6 were highly expressed in GT cells, suggesting that IL-1β and IL-6 have certain nociceptive roles in GT. In the 4 patients with cold intolerance, the intensity of IL-1β and IL-6 staining was also strong, suggesting that they may not play a role in the cold hypersensitivity. However, since there are only 4 patients with cold intolerance, it's necessary to conduct further in-depth research using a larger sample size. The specific role of CGRP in GT has not been found yet.

Non-invasive load monitoring based on deep learning to identify unknown loads

With the rapid development of smart grids, society has become increasingly urgent to solve the problems of low energy utilization efficiency and high energy consumption. In this context, load identification has become a key element in formulating scientific and effective energy consumption plans and reducing unnecessary energy waste. However, traditional load identification methods mainly focus on known electrical equipment, and accurate identification of unknown electrical equipment still faces significant challenges. A new encoding feature space based on Triplet neural networks is proposed in this paper to detect unknown electrical appliances using convex hull coincidence degree. Additionally, transfer learning is introduced for the rapid updating of the pre-classification model's self-incrementing class with the unknown load. In experiments, the effectiveness of our method is successfully tested on the PLAID dataset. The accuracy of unknown load identification reached 99.23%. Through this research, we expect to bring a new idea to the field of load identification to meet the urgent need for the identification of unknown electrical appliances in the development of smart grids.

Expression of MHC II in DRG neurons attenuates paclitaxel-induced cold hypersensitivity in male and female mice

Chemotherapy is often a life-saving treatment, but the development of intractable pain caused by chemotherapy-induced peripheral neuropathy (CIPN) is a major dose-limiting toxicity that restricts cancer survival rates. Recent reports demonstrate that paclitaxel (PTX) robustly increases anti-inflammatory CD4+ T cells in the dorsal root ganglion (DRG), and that T cells and anti-inflammatory cytokines are protective against CIPN. However, the mechanism by which CD4+ T cells are activated, and the extent cytokines released by CD4+ T cells target DRG neurons are unknown. Here, we are the first to detect major histocompatibility complex II (MHCII) protein in mouse DRG neurons and to find CD4+ T cells breaching the satellite glial cell barrier to be in close proximity to neurons, together suggesting CD4+ T cell activation and targeted cytokine release. MHCII protein is primarily expressed in small nociceptive neurons in male and female mouse DRG but increased after PTX in small nociceptive neurons in only female DRG. Reducing one copy of MHCII in small nociceptive neurons decreased anti-inflammatory IL-10 and IL-4 producing CD4+ T cells in naïve male DRG and increased their hypersensitivity to cold. Administration of PTX to male and female mice that lacked one copy of MHCII in nociceptive neurons decreased anti-inflammatory CD4+ T cells in the DRG and increased the severity of PTX-induced cold hypersensitivity. Collectively, our results demonstrate expression of MHCII protein in mouse DRG neurons, which modulates cytokine producing CD4+ T cells in the DRG and attenuates cold hypersensitivity during homeostasis and after PTX treatment.

Exploratory study of cold hypersensitivity in Japanese women: genetic associations and somatic symptom burden

Temperature perception is essential for humans to discern the environment and maintain homeostasis. However, some individuals experience cold hypersensitivity, characterized by a subjective feeling of coldness despite ambient environmental temperatures being normal, the underlying mechanisms of which are unknown. In this study, we aimed to investigate the relationship between subjective cold symptoms and somatic burden or single nucleotide polymorphisms to understand the causes of cold hypersensitivity. We conducted an online questionnaire survey [comprising 30 questions, including past medical history, subjective symptoms of cold hypersensitivity, and the Somatic Symptom Scale-8 (SSS-8)]. Respondents were 1200 Japanese adult female volunteers (age: 20-59 years), recruited between April 21 and May 25, 2022, who were customers of MYCODE, a personal genome service in Japan. Among the 1111 participants, 599 (54%) reported cold hypersensitivity. Higher cold hypersensitivity severity was positively associated with the SSS-8 scores. Additionally, a genome-wide association study for cold hypersensitivity was conducted using array-based genomic data obtained from genetic testing. We identified 11 lead variants showing suggestive associations (P < 1 × 10-5) with cold hypersensitivity, some of which showed a reasonable change in expression in specific tissues in the Genotype-Tissue Expression database. The study findings shed light on the underlying causes of cold hypersensitivity.

Efficacy and safety of thalidomide in children with monogenic autoinflammatory diseases: a single-center, real-world-evidence study

BACKGROUND

Monogenic autoinflammatory diseases (AIDs) are rare inflammatory diseases caused by genetic variants. The pathogenesis is complex and treatment options are limited. This study aimed to describe the safety and efficacy of thalidomide in the treatment of monogenic AIDs.

METHODS

This was a single-center, single-arm, real-world study. From September 2016 to August 2021, patients with monogenic AIDs who met the inclusion and exclusion criteria were given thalidomide for 12 months. There was a 3-month run-in period before dosing. The efficacy and adverse events were evaluated and recorded every 3 months. After 3 and 12 months of thalidomide treatment, clinical manifestations, disease activity score, inflammatory markers, and background medication adjustments were compared with baseline for efficacy analyses.

RESULTS

A total of 16 patients entered this study, including 3 with Aicardi-Goutières syndrome (AGS), 4 Blau syndrome, 2 chronic infantile neurologic cutaneous articular syndrome (CINCA), 2 A20 haploinsufficiency (HA20), 1 adenosine deaminase 2 deficiency(DADA2), 1 familial Mediterranean fever (FMF),1 tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS), 1 PLCγ2-associated antibody deficiency and immune dysregulation (PLAID), and 1 stimulator of interferon genes-associated vasculopathy with onset in infancy(SAVI). The efficacy rate in the 16 patients after 3-month and 12-month thalidomide treatment in patients was 56.3%. Twelve patients completed the study, the fever improved in all of them, rash improved in 7 patients, and 5 patients stopped using glucocorticoids or other immunosuppressive agents. C-reactive protein was normal in 8 patients and erythrocyte sedimentation rate was normal in 11 patients. Anorexia and nausea occurred in 2 cases, with no other reported drug-related adverse reactions.

CONCLUSION

The largest cohort of monogenic AIDs with the treatment of thalidomide demonstrated that thalidomide can help reduce disease activity and inflammation, reduce the dosage of glucocorticoids, and improve clinical outcomes. Thalidomide is relatively safe in monogenic AIDs.

NLRC4 gain-of-function variant is identified in a patient with systemic lupus erythematosus

NLRC4 gain-of-function variants are known to cause various autoinflammatory phenotypes, including familial cold autoinflammatory syndrome (FCAS4) and NLRC4 macrophage activation syndrome (NLRC4-MAS). However, to date, no study has linked NLRC4 gain-of-function variants to systemic lupus erythematosus (SLE). In this study, we identified a novel NLRC4 W655S variant in an SLE patient and her son, who had neonatal lupus complicated with macrophage activation syndrome. Our in vitro experiments demonstrated that the W655S NLRC4 increased ASC speck formation and mature IL-1β secretion compared to the wild-type NLRC4. In addition, the patient had elevated levels of IL-1β and IL-18 in both serum and PBMCs. RNA sequencing showed that NF-κB and interferon signaling pathways were significantly activated in the patient compared to healthy controls. Furthermore, gene set enrichment analysis revealed upregulation of NLRC4-related pathways in patient PBMCs. In conclusion, our study identified the NLRC4 W655S variant in a patient with SLE. This is the first report linking inflammasomopathy to monogenic SLE. Our findings suggest that inflammasome activation may be a critical driver in the pathogenicity of lupus, and autoinflammatory pathways may play important roles in the development of the disease.

No NLRP3 inflammasome activity in kidney epithelial cells, not even when the NLRP3-A350V Muckle-Wells variant is expressed in podocytes of diabetic mice

Background

The NLRP3 inflammasome integrates several danger signals into the activation of innate immunity and inflammation by secreting IL-1β and IL-18. Most published data relate to the NLRP3 inflammasome in immune cells, but some reports claim similar roles in parenchymal, namely epithelial, cells. For example, podocytes, epithelial cells critical for the maintenance of kidney filtration, have been reported to express NLRP3 and to release IL-β in diabetic kidney disease, contributing to filtration barrier dysfunction and kidney injury. We questioned this and hence performed independent verification experiments.

Methods

We studied the expression of inflammasome components in human and mouse kidneys and human podocytes using single-cell transcriptome analysis. Human podocytes were exposed to NLRP3 inflammasome agonists in vitro and we induced diabetes in mice with a podocyte-specific expression of the Muckle-Wells variant of NLRP3, leading to overactivation of the Nlrp3 inflammasome (Nphs2Cre;Nlrp3A350V) versus wildtype controls. Phenotype analysis included deep learning-based glomerular and podocyte morphometry, tissue clearing, and STED microscopy of the glomerular filtration barrier. The Nlrp3 inflammasome was blocked by feeding ß-hydroxy-butyrate.

Results

Single-cell transcriptome analysis did not support relevant NLRP3 expression in parenchymal cells of the kidney. The same applied to primary human podocytes in which NLRP3 agonists did not induce IL-1β or IL-18 secretion. Diabetes induced identical glomerulomegaly in wildtype and Nphs2Cre;Nlrp3A350V mice but hyperfiltration-induced podocyte loss was attenuated and podocytes were larger in Nphs2Cre;Nlrp3A350V mice, an effect reversible with feeding the NLRP3 inflammasome antagonist ß-hydroxy-butyrate. Ultrastructural analysis of the slit diaphragm was genotype-independent hence albuminuria was identical.

Conclusion

Podocytes express low amounts of the NLRP3 inflammasome, if at all, and do not produce IL-1β and IL-18, not even upon introduction of the A350V Muckle-Wells NLRP3 variant and upon induction of podocyte stress. NLRP3-mediated glomerular inflammation is limited to immune cells.

Systematic Review of Safety and Efficacy of IL-1-Targeted Biologics in Treating Immune-Mediated Disorders

Background

The cytokine interleukin (IL)-1 plays a pivotal role in immune-mediated disorders, particularly in autoinflammatory diseases. Targeting this cytokine proved to be efficacious in treating numerous IL-1-mediated pathologies. Currently, three IL-1 blockers are approved, namely anakinra, canakinumab and rilonacept, and two additional ones are expected to receive approval, namely gevokizumab and bermekimab. However, there is no systematic review on the safety and efficacy of these biologics in treating immune-mediated diseases.

Objective

To evaluate safety and efficacy of anakinra, canakinumab, rilonacept, gevokizumab, and bermekimab for the treatment of immune-mediated disorders compared to placebo, standard-of-care treatment or other biologics.

Methods

The PRISMA checklist guided the reporting of the data. We searched the PubMed database between 1 January 1984 and 31 December 2020 focusing on immune-mediated disorders. Our PubMed literature search identified 7363 articles. After screening titles and abstracts for the inclusion and exclusion criteria and assessing full texts, 75 articles were included in a narrative synthesis.

Results

Anakinra was both efficacious and safe in treating cryopyrin-associated periodic syndromes (CAPS), familial Mediterranean fever (FMF), gout, macrophage activation syndrome, recurrent pericarditis, rheumatoid arthritis (RA), and systemic juvenile idiopathic arthritis (sJIA). Conversely, anakinra failed to show efficacy in graft-versus-host disease, Sjögren’s syndrome, and type 1 diabetes mellitus (T1DM). Canakinumab showed efficacy in treating CAPS, FMF, gout, hyper-IgD syndrome, RA, Schnitzler’s syndrome, sJIA, and TNF receptor-associated periodic syndrome. However, use of canakinumab in the treatment of adult-onset Still’s disease and T1DM revealed negative results. Rilonacept was efficacious and safe for the treatment of CAPS, FMF, recurrent pericarditis, and sJIA. Contrarily, Rilonacept did not reach superiority compared to placebo in the treatment of T1DM. Gevokizumab showed mixed results in treating Behçet’s disease-associated uveitis and no benefit when assessed in T1DM. Bermekimab achieved promising results in the treatment of hidradenitis suppurativa.

Conclusions

This systematic review of IL-1-targeting biologics summarizes the current state of research, safety, and clinical efficacy of anakinra, bermekimab, canakinumab, gevokizumab, and rilonacept in treating immune-mediated disorders.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021228547.

Comparison of Efficacy and Safety of Lumbar Sympathetic Radiofrequency Thermocoagulation Versus Chemical Lumbar Sympathectomy in the Treatment of Cold Hypersensitivity in the Hands and Feet: A Retrospective Study

BACKGROUND

Cold hypersensitivity in the hands and feet (CHHF) is a disease characterized by abnormal cold in the limbs with limited treatment options. Compared to traditional drug therapy, lumbar sympathectomy is a new minimally invasive surgical method for treating CHHF.

OBJECTIVES

The present study aimed to compare the efficacy and safety of lumbar sympathetic radiofrequency thermocoagulation (RFT) and chemical lumbar sympathectomy (CLS) in treating CHHF.

STUDY DESIGN

A single-center, retrospective, observational study.

SETTING

Department of Anesthesiology and Pain Medicine, Jiaxing, China.

METHODS

A total of 102 patients with CHHF who underwent lumbar sympathectomy from January 2016 to April 2020 were included in this study. According to the mode of operation, the patients were divided into 2 groups: CLS (n = 56) and RFT (n = 46). All patients were treated under the guidance of computed tomography (CT). The foot temperature (T) and peripheral perfusion index (PI) were compared between the 2 groups before and after treatment. The 2 groups' visual analog scale (VAS) scores were evaluated before the operation and 1 day, 1 month, 3 months, 6 months, and 1 year after the treatment. The postoperative recurrence rate of the 2 groups was observed 1 year after treatment. The short and long-term complications during the postoperative follow-up were recorded.

RESULTS

All patients completed the operation successfully. No significant difference was noted in the gender, age, course of the disease, preoperative T and PI, and postoperative T and PI between the 2 groups (P > 0.05). The postoperative T and PI were significantly increased compared to preoperative in both groups (P < 0.05). No significant difference was observed in T and PI between the 2 groups (P > 0.05), and no significant difference was recorded in VAS scores between the 2 groups 1 day and 1 month after the treatment (P > 0.05). The VAS scores at 3 months, 6 months, and 1 year after the treatment were significantly lower in the RFT group compared to the CLS group (P < 0.05). During the 1-year follow-up, patients who received CLS had a higher risk of recurrence than RFT treatment (P < 0.05). The RFT group treatment of CHHF showed better long-term outcomes than the CLS group. About 12.5% of patients in the CLS group and 6.5% in the RFT group had postoperative complications, including pain at the puncture site and genitofemoral neuralgia. However, no severe complications or deaths were observed in either of the 2 groups.

LIMITATIONS

The was a single-center, retrospective, non-randomized study, which is a major limitation of this study.

CONCLUSIONS

Lumbar sympathetic RFT had better long-term efficacy, lower recurrence, and fewer complications than the chemical lumbar sympathectomy when treating CHHF.

CT-guided Chemical Lumbar Sympathectomy in the Treatment of Cold Hypersensitivity in the Hands and Feet

BACKGROUND

Cold hypersensitivity in the hands and feet is a common clinical symptom in Asian women. Currently, treatment of cold hypersensitivity in the hands and feet is still limited to traditional Chinese medicine, mainly herbal medicine. However, many patients with cold hypersensitivity in the hands and feet in China are not satisfied with the therapeutic effect of herbal medicine, and took medication for a longer time. Chemical lumbar sympathectomy is widely used in the treatment of plantar hyperhidrosis, diabetic foot, recalcitrant erythromelalgia, and other diseases.

OBJECTIVES

This study was conducted to evaluate the short-term as well as long-term efficacy, complications, and patient satisfaction of chemical lumbar sympathectomy during treatment cold hypersensitivity in the hands and feet.

STUDY DESIGN

A retrospective, observational study.

SETTING

Department of Anesthesiology and Pain Medicine, Jiaxing, China.

METHODS

A retrospective study of 72 patients with cold hypersensitivity in the hands and feet who received chemical lumbar sympathectomy treatment in our hospital from January 2015 to October 2018 was conducted. The heart rate, non-invasive blood pressure, oxygen saturation, visual analog scale, perfusion index, and plantar temperature were monitored and recorded in before treatment (T1) and after treatment (T2) groups. The patients were followed up on day 1, at week 1, 1 month, 3 months, 6 months, one year, and 2 years after operation for satisfaction, complications, and recurrence.

RESULTS

There were no significant differences in heart rate, non-invasive blood pressure, and oxygen saturation between T1 and T2 groups (P > 0.05). Perfusion index and plantar temperature in T2 group were remarkably higher than T1 group, and the difference was statistically significant (P < 0.01). The visual analog scale score of the T2 group was significantly reduced (P < 0.01). Of all the patients who underwent chemical lumbar sympathectomy, the postoperative therapeutic effect was effective in 63 cases (87.5%) and ineffective in 9 cases (12.5%). Among the effective patients, the postoperative curative effect was shown to be excellent in 47 cases and improved in 16 cases. According to the follow-up results at day 1, 1 week, 1 month, 3 months, 6 months, 1 year, and 2 years after operation, the satisfaction rate was 87.5%, 87.5%, 81.9%, 61.1%, 52.7%, 41.6%, and 34.7%, respectively. There were no serious complications observed and 23 patients relapsed after two years. Multivariate logistic regression analysis results showed that the effect of visual analog scale (OR = 7.312, 95% CI: 1.598 - 33.646, P = 0.011) and plantar temperature (OR = 0.470, 95% CI: 0.288 - 0.766, P = 0.002) on therapeutic effect showed has statistical significance; the effect of gender (OR = 0.654, 95% CI: 0.134 - 3.181, P = 0.599), age (OR = 0.975, 95% CI: 0.916 - 1.039, P = 0.441), perfusion index (OR = 0.710, 95% CI: 0.367 - 1.375, P = 0.310), and disease course (OR = 1.019, 95% CI: 0.997 - 1.042, P = 0.088) on therapeutic effect showed no statistical significance. The effect of gender (OR = 0.451, 95% CI 0.131 - 1.554, P = 0.207), age (OR = 0.961, 95% CI 0.912 - 1.013, P = 0.141), and course of disease (OR = 1.006, 95% CI 0.997 - 1.015, P = 0.203) on postoperative recurrence showed no statistical significance.

LIMITATIONS

The nonrandomized, single-center, small sample size, retrospective design is a major limitation of this study.

CONCLUSIONS

Chemical lumbar sympathectomy is a valid treatment option for cold hypersensitivity in hands and feet, and computed tomography-guided percutaneous puncture chemical lumbar sympathectomy has the advantages of high success rate, less invasion, less complications, and repeatablity.

Somatic mosaicism in adult-onset TNF receptor-associated periodic syndrome (TRAPS)

BACKGROUND

Somatic mosaicism is to date an uncommon finding in genetic autoinflammatory syndromes such as Cryopyrin-associated periodic syndrome, Blau syndrome, and TNF receptor-associated periodic syndrome (TRAPS). However, somatic mosaicism may be particularly important in adult-onset or atypical phenotypes of these conditions. Herein, we report a unique adult-onset TRAPS patient presenting with intermittent daily fever for 3 weeks, rash, peritonitis, and lymphadenopathy, who was found with hematopoietic mosaicism involving different white blood cell populations.

METHODS

Patient's lymphocyte genomic DNA was initially analyzed by periodic fever seven-gene next-generation sequencing panel. Genomic DNAs extracted from patient's hair roots, buccal swab, and subpopulations of white blood cells were subsequently examined on the identified TNFRSF1A variant using Sanger sequencing.

RESULTS

A de novo mosaic missense variant, c.265 T>C(p.Phe89Leu), in the TNFRSF1A gene was found in the patient's buccal swab, B cells, neutrophils, and NK cells but not detected in monocytes, T cells, and hair roots.

CONCLUSION

These data provide additional information about somatic mosaicism in autoinflammatory conditions and provide new insights regarding cellular players that are indispensable for the phenotypic expression of TRAPS.

Periodic fevers and other autoinflammatory diseases

Autoinflammatory diseases represent a relatively new and rapidly evolving group of rare disorders associated with mutations of genes encoding proteins with a key regulatory role in inflammatory response. Gradual discovery of mechanisms that link genetic disorder with its biochemical and immunological consequences leading to continuous or episodic inflammatory stimulation has enabled introduction of directed immunotherapies. Periodic fever syndromes belong to the so far best-known entities: familial Mediterranean fever, mevalonate kinase deficiency, cryopyrinopathies and TNF-receptor associated periodic syndrome. These inherited disorders usually manifest in childhood with variably long febrile episodes accompanied with the spectrum of other skin and organ inflammatory features and elevation of laboratory markers of inflammation. Uncontrolled disease may lead to secondary amyloidosis. Directed anti-inflammatory therapy can prevent evolution of organ damage. In children benign syndrome of periodic fever with aphtae, pharyngitis and cervical adenitis is the most common self-limited disorder without clear genetic disposition. Following other autoinflammatory disease groups are described - pyogenic syndromes, disorders with skin and bone manifestations, granulomatous diseases, monogenic vasculopathies and diseases associated with proteasome disorder. Diagnosis of autoinflammatory diseases is often delayed due to their extreme rarity. Increasing efficacy and availability of molecular-genetic testing and centralization of diagnostics and clinical care in a specialized center for children as well as adults can in the future improve quality of care for patients with these rare conditions. Keywords: autoinflammatory diseases (AID), periodic fever syndromes, FMF, CAPS, MKD, TRAPS, PFAPA, NGS.

Confounding role of tumor necrosis factor in cryopyrin-associated periodic syndromes

The NLRP3 inflammasome is a critical component of the innate immune system and can be activated in response to microbial and endogenous danger signals. Activation of the NLRP3 inflammasome results in caspase-1-dependent secretion of the proinflammatory cytokines IL-1β and IL-18. Gain-of-function missense mutations in NLRP3 result in a group of autoinflammatory diseases collectively known as the cryopyrin-associated periodic syndromes (CAPS). CAPS patients have traditionally been successfully treated with therapeutics targeting the IL-1 pathway; however, there are a number of identified CAPS patients who show only a partial response to IL-1 blockade. In this issue of the JCI, McGeough et al. demonstrated that TNF-α, in addition to IL-1β, plays an important role in promoting NLRP3 inflammasomopathies.