A case of Schnitzler syndrome with unusual immunoglobulin A gammopathy exacerbated by COVID-19 infection

Schnitzler syndrome (SchS) is a rare autoinflammatory disease characterized by chronic urticarial rash and monoclonal immunoglobulin M (IgM) or IgG gammopathy. Viruses, including COVID-19, activate the innate immune system, therefore SchS, in which the innate immune system is improperly activated, is hypothesized to be exacerbated by viral infection. However, there were no reported SchS cases exacerbated by any viral infection. Here, we report a SchS case with an unusual IgA gammopathy manifested and exacerbated by COVID-19 infection. This report advocates the need for recognizing unusual cases of SchS with monoclonal IgA, and following up on paraprotein like IgA even when it is initially undetectable in cases with SchS symptoms. We also hypothesize that existing autoinflammatory diseases may be exacerbated by COVID-19 infection in the case of a combination of these diseases.

Truncating NFKB1 variants cause combined NLRP3 inflammasome activation and type I interferon signaling and predispose to necrotizing fasciitis

In monogenic autoinflammatory diseases, mutations in genes regulating innate immune responses often lead to uncontrolled activation of inflammasome pathways or the type I interferon (IFN-I) response. We describe a mechanism of autoinflammation potentially predisposing patients to life-threatening necrotizing soft tissue inflammation. Six unrelated families are identified in which affected members present with necrotizing fasciitis or severe soft tissue inflammations. Exome sequencing reveals truncating monoallelic loss-of-function variants of nuclear factor κ light-chain enhancer of activated B cells (NFKB1) in affected patients. In patients' macrophages and in NFKB1-variant-bearing THP-1 cells, activation increases both interleukin (IL)-1β secretion and IFN-I signaling. Truncation of NF-κB1 impairs autophagy, accompanied by the accumulation of reactive oxygen species and reduced degradation of inflammasome receptor nucleotide-binding oligomerization domain, leucine-rich repeat-containing protein 3 (NLRP3), and Toll/IL-1 receptor domain-containing adaptor protein inducing IFN-β (TRIF), thus leading to combined excessive inflammasome and IFN-I activity. Many of the patients respond to anti-inflammatory treatment, and targeting IL-1β and/or IFN-I signaling could represent a therapeutic approach for these patients.

Case report: Cerebral sinus vein thrombosis in VEXAS syndrome

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, and somatic) syndrome is a newly described hemato-inflammatory acquired monogenic entity that presents in adulthood. One of the main features of VEXAS syndrome is a high venous thromboembolism (VTE) burden, with approximately 30-40% experiencing lower extremity deep vein thrombosis and a lower incidence of pulmonary embolism at approximately 10%. To date, VEXAS syndrome has not been associated with rarer forms of VTE such as cerebral sinus vein thrombosis (CSVT) and Budd-Chiari syndrome, which are well-recognized vascular manifestations in Behcet's disease, another autoinflammatory vasculitic disease. Herein, we describe a case of acute severe extensive and fatal CSVT in a patient with VEXAS syndrome. The event occurred during a period of apparently quiescent inflammatory status, while the patient was receiving tocilizumab and a low dose of glucocorticoids. Despite treatment with anticoagulation, high-dose glucocorticoids, endovascular thrombectomy, and intracranial pressure-lowering agents, the patient suffered severe neurologic damage and ultimately succumbed to the condition 3 weeks after the onset of CSVT. To the best of our knowledge, this is the first reported case of CVST in a patient with VEXAS syndrome.

The First Case of a Korean Patient with a Mutation-Confirmed Tumor Necrosis Factor Receptor-Associated Periodic Syndrome

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS, OMIM: #142680) is a rare autoinflammatory disease (AID) with recurrent febrile episodes. To our knowledge, we report herein the first case of a patient with TRAPS in South Korea whose symptoms included fever, arthralgia, abdominal pain, rash, myalgia, cough, and lymphadenopathy. A pathogenic de novo mutation, c.175T>C (p.Cys59Arg), in the tumor necrosis factor receptor superfamily member 1A (TNFRSF1A) gene, was confirmed by gene sequencing. The patient has been with tocilizumab (an interleukin-6 inhibitor); tocilizumab administration every other week has completely alleviated the patient's symptoms. Our report further expands the clinical spectrum of patients with TRAPS and reaffirms the use of tocilizumab as a viable alternative treatment option for those patients who are unsatisfactorily responsive to other commonly used biologics, such as canakinumab, anakinra, infliximab, and etanercept. Furthermore, our report may aid in increasing awareness about the existence of mutation-confirmed TRAPS in South Korea in addition to emphasizing the importance of actively pursuing genetic testing to correctly diagnose rare AID.

Sustained Pericarditis Recurrence Risk Reduction With Long-Term Rilonacept

BACKGROUND

Rilonacept, a once-weekly interleukin-1 alpha and beta cytokine trap, reduced pericarditis recurrence in the phase 3 study, RHAPSODY (Rilonacept Inhibition of Interleukin-1 Alpha and Beta for Recurrent Pericarditis: A Pivotal Symptomatology and Outcomes Study). The RHAPSODY long-term extension further explored recurrent pericarditis natural history and treatment duration decision-making during 24 additional months of open-label rilonacept treatment.

METHODS AND RESULTS

Seventy-four patients commenced the long-term extension, with a median (maximum) total rilonacept duration of 22 (35) months. Individually, 18 months after the most proximal pericarditis recurrence, investigators decided to continue rilonacept on study, suspend rilonacept for off-treatment observation (rescue allowed), or discontinue the study. The annualized incidence of pericarditis recurrence on rilonacept up to the 18-month decision milestone was 0.04 events/patient-year versus 4.4 events/patient-year prestudy while on oral therapies. At the 18-month decision milestone, 64% (33/52) continued rilonacept, 15% (8/52) suspended rilonacept for observation, and 21% (11/52) discontinued the study. Among the 33 patients (1/33; 3.0%) continuing rilonacept (median time to recurrence could not be estimated due to too few events), a single recurrence occurred 4 weeks after a treatment interruption. Among patients suspending rilonacept, 75% (6/8) experienced recurrence (median time to recurrence, 11.8 weeks [95% CI, 3.7 weeks to not estimable]). There was a 98% reduction in risk of pericarditis recurrence among patients continuing rilonacept treatment after the 18-month decision milestone versus those suspending treatment for observation (hazard ratio, 0.02; P<0.0001).

CONCLUSIONS

In the RHAPSODY long-term extension, continued rilonacept treatment resulted in continued response; treatment suspension at the 18-month decision milestone was associated with pericarditis recurrence.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03737110.

The Complexity of Being A20: From Biological Functions to Genetic Associations

A20, encoded by TNFAIP3, is a critical negative regulator of immune activation. A20 is a ubiquitin editing enzyme with multiple domains, each of which mediates or stabilizes a key ubiquitin modification. A20 targets diverse proteins that are involved in pleiotropic immunologic pathways. The complexity of A20-mediated immunomodulation is illustrated by the varied effects of A20 deletion in different cell types and disease models. Clinically, the importance of A20 is highlighted by its extensive associations with human disease. A20 germline variants are associated with a wide range of inflammatory diseases, while somatic mutations promote development of B cell lymphomas. More recently, the discovery of A20 haploinsufficiency (HA20) has provided real world evidence for the role of A20 in immune cell function. Originally described as an autosomal dominant form of Behcet's disease, HA20 is now considered a complex inborn error of immunity with a broad spectrum of immunologic and clinical phenotypes.

NLRP1-associated autoinflammatory disease with epithelial dyskeratosis

Several gain-of-function variants in NLRP1 cause a distinctive autoinflammatory disease reported under different names featuring mainly skin and mucosal involvement and variable systemic signs. Here, we report a new case of NLRP1-associated autoinflammatory disease in a 6-year-old Peruvian girl, who presented with confluent hyperkeratotic plaques that drained purulent material with subsequent scarring. A c.3641C > G (p. Pro1214Arg) variant that has been previously been reported was found in NLRP1 and was not present in either parent. The term NLRP1-associated autoinflammatory disease with epithelial dyskeratosis (NADED) is proposed to encompass all reported cases, which have received different nomenclature so far.

Cigarette smoking and risk of adult-onset Still disease: a propensity score matching analysis

BACKGROUND

Environmental factors play an important role in the pathogenesis of rheumatic diseases. Smoking is thought to be a risk factor for autoimmune rheumatic diseases.

AIMS

The purpose of the present study was to assess the association between smoking and adult-onset Still disease (AOSD) and the effect of smoking on outcomes of this disease.

METHODS

In this case-control study, patients with AOSD who met the Yamaguchi criteria, were older than 16 years at the disease onset and were in follow-up for at least 12 months were consecutively enrolled in the study. The outcome of AOSD was assessed by acquiring remission on treatment, remission off treatment, time to remission and rate of flare. The smoking status of participants was defined by direct or phone interviews. Individuals who had smoked daily for at least 6 months were defined as a smoker. We performed propensity score matching analyses by using four parameters, including age, sex, educational status and marital status.

RESULTS

Propensity score matching resulted in 72 patients with AOSD and 216 matched controls. The number of ever smokers in the AOSD and control groups were 11 (15.3%) and 25 (11.6%) respectively. There was no significant increase in the risk of AOSD in multivariate analysis after adjustment for age, sex, marital status and educational level. There were no significant differences in the outcomes of AOSD between ever and never smokers.

CONCLUSIONS

Smoking probably is not a risk factor for AOSD and did not affect the response to treatment.

Unraveling the microbiome-metabolome nexus: a comprehensive study protocol for personalized management of Behçet's disease using explainable artificial intelligence

The presented study protocol outlines a comprehensive investigation into the interplay among the human microbiota, volatilome, and disease biomarkers, with a specific focus on Behçet's disease (BD) using methods based on explainable artificial intelligence. The protocol is structured in three phases. During the initial three-month clinical study, participants will be divided into control and experimental groups. The experimental groups will receive a soluble fiber-based dietary supplement alongside standard therapy. Data collection will encompass oral and fecal microbiota, breath samples, clinical characteristics, laboratory parameters, and dietary habits. The subsequent biological data analysis will involve gas chromatography, mass spectrometry, and metagenetic analysis to examine the volatilome and microbiota composition of salivary and fecal samples. Additionally, chemical characterization of breath samples will be performed. The third phase introduces Explainable Artificial Intelligence (XAI) for the analysis of the collected data. This novel approach aims to evaluate eubiosis and dysbiosis conditions, identify markers associated with BD, dietary habits, and the supplement. Primary objectives include establishing correlations between microbiota, volatilome, phenotypic BD characteristics, and identifying patient groups with shared features. The study aims to identify taxonomic units and metabolic markers predicting clinical outcomes, assess the supplement's impact, and investigate the relationship between dietary habits and patient outcomes. This protocol contributes to understanding the microbiome's role in health and disease and pioneers an XAI-driven approach for personalized BD management. With 70 recruited BD patients, XAI algorithms will analyze multi-modal clinical data, potentially revolutionizing BD management and paving the way for improved patient outcomes.

Genetic variations in NLRP3 and NLRP12 genes in adult-onset patients with autoinflammatory diseases: a comparative study

Objectives

Cryopyrin-associated periodic syndrome or NLRP3-associated autoinflammatory disease (NLRP3-AID) and NLRP12-AID are both Mendelian disorders with autosomal dominant inheritance. Both diseases are rare, primarily reported in the pediatric population, and are thought to be phenotypically indistinguishable. We provide the largest cohort of adult-onset patients and compared these diseases and the gene variant frequency to population controls.

Methods

A cohort of adult patients with AIDs were retrospectively studied. All underwent molecular testing for periodic fever syndrome gene panels after extensive and negative workups for systemic autoimmune and other related diseases. Patients were divided into Group 1- NLRP3-AID patients with NLRP3 variants (N=15), Group 2- NLRP12-AID with NLRP12 variants (N=14) and Group 3- both NLRP3 and NLRP12 (N=9) variants. Exome sequence data of two large control populations including the ARIC study were used to compare gene variant distribution and frequency.

Results

All 38 patients were Caucasian with women accounting for 82%. Median age at diagnosis was 41 ± 23 years and the disease duration at diagnosis was 14 ± 13 years. We identified statistically significant differences between the groups, notably that gastrointestinal symptoms as well as evaluations for same were significantly more frequent in patients with NLRP12 variants, and headaches/dizziness were less common among the NLRP12 patients. Livedo reticularis was noted in four patients, exclusively among NLRP12 carriers. Over 50% of patients in Groups 1 and 2 carry low-frequency disease-associated variants, while the remaining carry rare variants. We unprecedently identified digenic variants, i.e., the coexistence of NLRP3 and NLRP12, which were either both low frequency or low frequency/rare. Allele frequencies of all variants identified in our cohort were either absent or significantly lower in the control populations, further strengthening the evidence of susceptibility of these variants to SAID phenotypes.

Conclusion

Our comparative study shows that both NLRP3-AID and NLRP12-AID share similar clinical phenotypes, yet there are significant differences between them with regard to gastrointestinal and neurological symptoms. A spectrum of high to low genetic variations in both genes can contribute to SAID individually or in combination.

Cleavage-resistant RIPK1-induced autoinflammatory syndrome-A report of three generations with periodic fever and clinical response to colchicine

The clinical syndrome caused by cleavage-resistant RIPK1 is known as CRIA (Cleavage-resistant RIPK1-induced autoinflammatory) syndrome. We present a family with three generations affected by CRIA syndrome. Our index patient (P1), a boy born of a non-consanguineous marriage, developed recurrent episodes of fever after 5 months of age, with variable periodicity. His father (P2) and paternal grandmother also had periodic fever. At 23 months of age, P1 was diagnosed with renal biopsy-proven steroid-responsive nephrotic syndrome. His first visit to our center was at 2 years of age. At presentation, he had failure to thrive, microcytic hypochromic anemia, and elevated inflammatory markers and interleukin-6 levels. Amyloid A protein was elevated, serum creatinine was normal, and proteinuria resolved after addition of steroids. Next-generation sequencing showed heterozygous mutation (c.970G>A, p.Asp324His) in RIPK1. This mutation has been reported to cause CRIA syndrome. P2 and P1's asymptomatic younger brother had the same mutation. All the affected members showed variability with respect to frequency and duration of periodic fever as well as the age of onset. Both P1 and P2 had elevated amyloid A, with no evidence of renal dysfunction. P1 and P2 showed improvement in the intensity of fever spikes with colchicine treatment; however, both continue to have periodic fever.

Transition of Patients with Childhood-onset Rheumatic Diseases to Adult Medical Care in Japan

Medical advances in childhood-onset chronic diseases (CCDs) have significantly improved the prognosis of these diseases; however, they have also resulted in an increase in the number of cases requiring continued medical care in adulthood. The transition from the pediatric to adult healthcare system has recently received worldwide attention. In Japan, in the last decade, there has been a growing awareness of the transition to adult health care in each specialized chronic disease area with a childhood onset. This review focuses on transitional care in pediatric rheumatology, a CCD. Non-pediatric rheumatology departments, such as rheumatology and orthopedics, are potential counterparts for accepting pediatric rheumatology patients; however, several challenges must be met for a seamless transition to adult care. The characteristics of pediatric rheumatic diseases, which are rarer than non-pediatric rheumatic diseases, and the status and problems in transition will be outlined. The mission of pediatricians is not only to follow up diseases but also to support patients' independence. All medical staff and multidisciplinary professionals must cooperate toward this new goal.

Clinical characteristics and heterogeneity of generalized pustular psoriasis: A comparative study in a large retrospective cohort

Generalized pustular psoriasis (GPP) is a rare and potentially life-threatening skin disease and the clinical heterogeneity of which is largely unknown. Retrospective cohort analysis was conducted on hospitalized GPP patients between January 2010 and November 2022. A total of 416 patients with GPP and psoriasis vulgaris (PV) respectively were included, matched 1:1 by sex and age. The heterogeneity of GPP was stratified by PV history and age. Compared with PV, GPP was significantly associated with prolonged hospitalization (11.7 vs. 10.3 day, p < 0.001), elevated neutrophil lymphocyte ratio (NLR) (5.93 vs. 2.44, p < 0.001) and anemia (13.9% vs. 1.2%, p < 0.001). Moreover, GPP alone (without PV history) was a relatively severer subtype with higher temperature (37.6°C vs. 38.0°C, p = 0.002) and skin infections (5.2% vs. 11.4%, p = 0.019) than GPP with PV. For patients across different age, compared with juvenile patients, clinical features support a severer phenotype in middle-aged, including higher incidence of anaemia (7.5% vs. 16.0%, p = 0.023) and NLR score (3.83 vs. 6.88, p < 0.001). Interleukin-6 (r = 0.59), high density lipoprotein cholesterol (r = -0.56), albumin (r = -0.53) and C-reactive protein-to-albumin ratio (r = 0.49) were the most relevant markers of severity in GPP alone, GPP with PV, juvenile and middle-aged GPP, respectively. This retrospective cohort suggests that GPP is highly heterogeneous and GPP alone and middle-aged GPP exhibit severe disease phenotypes. More attention on the heterogeneity of this severe disease is warranted to meet the unmet needs and promote the individualized management of GPP.

Interleukin-11 and its eminent role in tissue fibrosis: a possible therapeutic target

Interleukin-11 is a cytokine from the IL-6 family of cytokines that includes IL-6 and oncostatin-M. Initially described for its role in platelet generation, it is now appreciated that this cytokine has multiple functions. Recently it has been found that IL-11 is critical in fibrosis in multiple different organ systems and systemically as in the autoimmune disease systemic sclerosis. Animal models of fibrosis have determined that animals with IL-11 receptor deletions have retarded fibrosis and that in wild-type animals IL-11 is found at the organ of fibrosis. Recent evidence suggests that IL-11 may be a master regulator of fibrosis regardless of end target organ. With the development of neutralizing antibodies targeting the cytokine in pre-clinical models this could be a possible therapeutic, in a disease in which no specific therapies exist. This review appraises the evidence of the role of IL-11 in tissue fibrosis, its signalling properties, and therapeutic targeting. The review ends with an appraisal of indications for which IL-11 modulation is targeted.

Subdural hemorrhage, macrocephaly, rash, and developmental delay in an infant: A pathogenic variant in NLRP3 causes CINCA/NOMID

Subdural hemorrhages (SDHs) in children are most often observed in abusive head trauma (AHT), a distinct form of traumatic brain injury, but they may occur in other conditions as well, typically with clear signs and symptoms of an alternative diagnosis. We present a case of an infant whose SDH initially raised the question of AHT, but multidisciplinary evaluation identified multiple abnormalities, including rash, macrocephaly, growth failure, and elevated inflammatory markers, which were all atypical for trauma. These, along with significant cerebral atrophy, ventriculomegaly, and an absence of other injuries, raised concerns for a genetic disorder, prompting genetic consultation. Clinical trio exome sequencing identified a de novo likely pathogenic variant in NLRP3, which is associated with chronic infantile neurological, cutaneous, and articular (CINCA) syndrome, also known as neonatal-onset multisystem inflammatory disease (NOMID). He was successfully treated with interleukin-1 blockade, highlighting the importance of prompt treatment in CINCA/NOMID patients. This case also illustrates how atraumatic cases of SDH can be readily distinguished from AHT with multidisciplinary collaboration and careful consideration of the clinical history and exam findings.

How to treat VEXAS syndrome: a systematic review on effectiveness and safety of current treatment strategies

OBJECTIVES

To evaluate the effectiveness and safety of current treatment strategies for the vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome.

METHODS

A protocolized systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed. Three databases were searched for reports on treatment strategies for VEXAS. Data from the included publications was extracted and a narrative synthesis was performed. Treatment response was recorded as complete (CR), partial (PR) or none (NR) depending on changes in clinical symptoms and laboratory parameters. Patient characteristics, safety data and previous treatments were analysed.

RESULTS

We identified 36 publications with a total of 116 patients; 113 (98.3%) were male. The identified reports included azacytidine (CR 9/36, 25%; PR 14/36, 38.9%), Janus kinase inhibitors (JAKi) (CR 11/33, 33%; PR 9/33, 27.3%), tocilizumab (CR 3/15, 20%; PR 6/15, 40%), allogeneic stem cell transplantation (CR 6/7, 85.7%; one patient died), anakinra (CR 4/5, 80%; NR 1/5, 20%), canakinumab (CR 1/2, 50%; PR 1/2, 50%) and glucocorticoid monotherapy (CR 1/6, 16.7%; PR 4/6, 66.7%). Individual reports were available for TNF inhibitors, rituximab and MTX. Data on adverse events were available for 67 patients (67/116, 57.8%) and included: pneumonia (12/67, 17.9%), other infections (9/67, 13.4%), venous thromboembolisms (6/67, 8.9%), cytopenias (4/67, 5.9%), and acute (4/67, 5.9%) and chronic graft-vs-host-disease (2/67, 2.9%).

CONCLUSION

Current data on VEXAS treatment are limited and inhomogeneous. Treatment decisions should be individualized. For the devolvement of treatment algorithms clinical trials are needed. Adverse events remain a challenge, especially an elevated risk for venous thromboembolism associated to JAKi treatment should be carefully considered.

Case Report: A de novo NLRP3 variant resulting in autoinflammatory disease in a Chinese newborn

Background

Cryopyrin-associated periodic syndromes (CAPS) have been considered autoinflammatory diseases resulting from NLRP3 gene mutations. In recent years, these conditions have been redefined as NLRP3-associated autoinflammatory diseases (NLRP3-AID). Our previous study highlighted a case of a Chinese individual carrying the de novo NLRP3 mutation.

Results

A female child carrying a de novo variant (c.1718T>G, p. L573W) in the NLRP3 gene was presented in this work. The patient manifested various symptoms, including recurrent fever, a rash resembling urticaria, arthritis, physical growth retardation, a notable prominence of the forehead, and a flat nose bridge. Additionally, inflammatory markers, like WBC count, PLT count, CRP, ESR, and IL-6 showed elevated levels. Additionally, we observed interstitial pulmonary disease in the patient, which is not frequently mentioned in previous studies. Notably, the proband did not present with any ocular, auditory, or neurological symptoms. After 12 weeks of subcutaneous canakinumab injection, there was a clear improvement in the patient's clinical manifestations and inflammatory markers.

Conclusion

Our study contributes to broadening the clinical spectrum of established pathogenic variants of NLRP3 gene, which are related to NLRP3-AID.

What General Neurologists Should Know about Autoinflammatory Syndromes?

Autoinflammatory disorders encompass a wide range of conditions with systemic and neurological symptoms, which can be acquired or inherited. These diseases are characterized by an abnormal response of the innate immune system, leading to an excessive inflammatory reaction. On the other hand, autoimmune diseases result from dysregulation of the adaptive immune response. Disease flares are characterized by systemic inflammation affecting the skin, muscles, joints, serosa, and eyes, accompanied by unexplained fever and elevated acute phase reactants. Autoinflammatory syndromes can present with various neurological manifestations, such as aseptic meningitis, meningoencephalitis, sensorineural hearing loss, and others. Early recognition of these manifestations by general neurologists can have a significant impact on the prognosis of patients. Timely and targeted therapy can prevent long-term disability by reducing chronic inflammation. This review provides an overview of recently reported neuroinflammatory phenotypes, with a specific focus on genetic factors, clinical manifestations, and treatment options. General neurologists should have a good understanding of these important diseases.

Deficiency of Interleukin-1 Receptor Antagonist: New Genetic Autoinflammatory Disease as a Diagnostic Challenge for Pediatricians

Deficiency of interleukin-1 receptor antagonist is a rare autoinflammatory disease that affects infants early in life. It often presents with systemic inflammation, skin and bone involvement. We present a 5-month-old boy who was hospitalized due to generalized erythematous pustular eruption with secondary impetigo, cellulitis, bronchiolitis, and elevated inflammatory markers. The patient was unresponsive to multiple courses of intravenous antibiotics, systemic, and topical steroid medications. The patient was evaluated by dermatology and rheumatology services among other subspecialities. Skin biopsy showed changes consistent with psoriasiform dermatitis, while bone scans showed multifocal osteomyelitis. The patient was started empirically on anakinra with improvement at 72 hours upon administration. This is one of the youngest reported case in the literature to be started on anakinra empirically prior to genetic confirmation of the mutation. A comprehensive literature review revealed that approximately 20 genetically confirmed patients, including our patient, have been reported with this genetic disease. It is imperative to recognize this disease early to achieve adequate response and remission. Therefore, clinical symptoms and the associated differential diagnosis for this disease should be constantly reassessed and reviewed by pediatricians and subspecialists to detect the disease as early as possible and reduce the high morbidity and mortality associated with delayed diagnosis and treatment.

Susceptibility of nucleotide-binding oligomerization domain 2 mutations to Whipple's disease

OBJECTIVES

Whipple's disease (WD) results from infection of the bacteria Tropheryma whipplei (TW). This disease is characterized by macrophage infiltration of intestinal mucosa and primarily affects Caucasian males. Genetic studies of host susceptibility are scarce. Nucleotide-binding oligomerization domain containing protein 2 (NOD2) is an innate immune sensor, resides mainly in monocytes/macrophages and contributes to defense against infection and inflammatory regulation. NOD2 mutations are associated with autoinflammatory diseases. We report the association of NOD2 mutations with TW and WD for the first time.

METHODS

A multicenter, retrospective study of three patients with WD was conducted. Patients received extensive multidisciplinary evaluations and were cared for by the authors. NOD2 and its association with infection and inflammation were schematically represented.

RESULTS

All patients were Caucasian men and presented with years of autoinflammatory phenotypes, including recurrent fever, rash, inflammatory arthritis, gastrointestinal symptoms, and elevated inflammatory markers. All patients underwent molecular testing using a gene panel for periodic fever syndromes and were identified to carry NOD2 mutations associated with NOD2-associated autoinflammatory disease. Despite initially negative gastrointestinal evaluations, repeat endoscopy with duodenal tissue biopsy ultimately confirmed WD. After initial ceftriaxone and maintenance with doxycycline and/or hydroxychloroquine, symptoms were largely controlled, though mild relapses occurred in follow up.

CONCLUSION

Both NOD2 and TW/WD are intensively involved in monocytes/macrophages. WD is regarded as a macrophage disease. NOD2 leucin rich repeat-associated mutations in monocytes/macrophages cause functional impairment of these cells and consequently may make the host susceptible for TW infection and WD, especially in the setting of immunosuppression.

Innate immune responses in Behçet disease and relapsing polychondritis

Behçet disease (BD) and relapsing polychondritis (RP) are chronic multisystem disorders characterized by recurrent flare-ups of tissue inflammation. Major clinical manifestations of BD are oral aphthae, genital aphthous ulcers, skin lesions, arthritis, and uveitis. Patients with BD may develop rare but serious neural, intestinal, and vascular complications, with high relapse rates. Meanwhile, RP is characterized by the inflammation of the cartilaginous tissues of the ears, nose, peripheral joints, and tracheobronchial tree. Additionally, it affects the proteoglycan-rich structures in the eyes, inner ear, heart, blood vessels, and kidneys. The mouth and genital ulcers with inflamed cartilage (MAGIC) syndrome is a common characteristic of BD and RP. The immunopathology of these two diseases may be closely related. It is established that the genetic predisposition to BD is related to the human leukocyte antigen (HLA)-B51 gene. Skin histopathology demonstrates the overactivation of innate immunity, such as neutrophilic dermatitis/panniculitis, in patients with BD. Monocytes and neutrophils frequently infiltrate cartilaginous tissues of patients with RP. Somatic mutations in UBA1, which encodes a ubiquitylation-related enzyme, cause vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome (VEXAS) with severe systemic inflammation and activation of myeloid cells. VEXAS prompts auricular and/or nasal chondritis, with neutrophilic infiltration around the cartilage in 52-60% of patients. Thus, innate immune cells may play an important role in the initiation of inflammatory processes underlying both diseases. This review summarizes the recent advances in our understanding of the innate cell-mediated immunopathology of BD and RP, with a focus on the common and distinct features of these mechanisms.

Tofacitinib, a suppressor of NOD2 expression, is a potential treatment for Blau syndrome

Introduction

Blau syndrome is a rare autosomal dominant autoinflammatory granulomatous disease caused by a mutation in the NOD2 gene. It is characterized by a clinical trial of granulomatous dermatitis, arthritis, and uveitis. Tofacitinib is a pan Janus kinase (JAK) inhibitor used for treatment of Blau syndrome and idiopathic sarcoidosis. Here, we evaluated its effect on inflammatory pathways associated with Blau syndrome. The effect of tofacitinib on downstream pathways regulated by mutant NOD2 was analyzed using luciferase assays with overexpression of NOD2 mutants.

Methods

The effect of tofacitinib on the upstream pathway for the induction of NOD2 expression and proinflammatory cytokine production was assessed using monocytic cell lines differentiated from Blau syndrome patient-derived induced pluripotent stem cells.

Results

Tofacitinib did not suppress the increased spontaneous transcriptional activity of NF-κB by mutant NOD2. In addition, mutant NOD2 was not involved in the transcription of ISRE and GAS, which are activated by type 1 and type 2 interferons (IFN), respectively. On the other hand, IFNγ induced the expression of NOD2, which led to the production of inflammatory cytokines by an autoinflammatory mechanism only in cells with mutant NOD2.

Discussion

Tofacitinib suppressed the induction of NOD2 by IFNγ, thereby inhibiting the production of pro-inflammatory cytokines. Thus, tofacitinib showed anti-inflammatory effects through suppression of NOD2 expression. The JAK inhibitor tofacitinib is a potential therapeutic agent for Blau syndrome because it suppresses the autoinflammation seen in Blau syndrome by inhibiting the expression of NOD2.

Identification of an IL-1 receptor mutation driving autoinflammation directs IL-1-targeted drug design

The interleukin 1 (IL-1) pathway signals through IL-1 receptor type 1 (IL-1R1) and emerges as a central mediator for systemic inflammation. Aberrant IL-1 signaling leads to a range of autoinflammatory diseases. Here, we identified a de novo missense variant in IL-1R1 (p.Lys131Glu) in a patient with chronic recurrent multifocal osteomyelitis (CRMO). Patient PBMCs showed strong inflammatory signatures, particularly in monocytes and neutrophils. The p.Lys131Glu substitution affected a critical positively charged amino acid, which disrupted the binding of the antagonist ligand, IL-1Ra, but not IL-1α or IL-1β. This resulted in unopposed IL-1 signaling. Mice with a homologous mutation exhibited similar hyperinflammation and greater susceptibility to collagen antibody-induced arthritis, accompanied with pathological osteoclastogenesis. Leveraging the biology of the mutation, we designed an IL-1 therapeutic, which traps IL-1β and IL-1α, but not IL-1Ra. Collectively, this work provides molecular insights and a potential drug for improved potency and specificity in treating IL-1-driven diseases.

An Update on Familial Mediterranean Fever

(1) Background: Familial Mediterranean Fever (FMF) is the prototypal autoinflammatory disease, characterized by recurrent bursts of neutrophilic inflammation. (2) Methods: In this study we look at the most recent literature on this condition and integrate it with novel information on treatment resistance and compliance. (3) Results: The canonical clinical presentation of FMF is in children with self-limited episodes of fever and polyserositis, associated with severe long-term complications, such as renal amyloidosis. It has been described anecdotally since ancient times, however only recently it has been characterized more accurately. We propose an updated overview on the main aspects of pathophysiology, genetics, diagnosis and treatment of this intriguing disease. (4) Conclusions: Overall, this review presents the all the main aspects, including real life outcome of the latest recommendation on treatment resistance of FMF, a disease, that not only helped understanding the pathophysiology of the auto inflammatory process but also the functioning of the innate immune system itself.

An immunogenetic investigation of 30 autoimmune and autoinflammatory diseases and their links to psychiatric disorders in a nationwide sample

Autoimmune and autoinflammatory diseases (AIIDs) involve a deficit in an individual's immune system function, whereby the immune reaction is directed against self-antigens. Many AIIDs have a strong genetic component, but they can also be triggered by environmental factors. AIIDs often have a highly negative impact on the individual's physical and mental wellbeing. Understanding the genetic underpinning of AIIDs is thus crucial both for diagnosis and for identifying individuals at high risk of an AIID and mental illness as a result thereof. The aim of the present study was to perform systematic statistical and genetic analyses to assess the role of human leukocyte antigen (HLA) alleles in 30 AIIDs and to study the links between AIIDs and psychiatric disorders. We leveraged the Danish iPSYCH Consortium sample comprising 65 534 individuals diagnosed with psychiatric disorders or selected as part of a random population sample, for whom we also had genetic data and diagnoses of AIIDs. We employed regression analysis to examine comorbidities between AIIDs and psychiatric disorders and associations between AIIDs and HLA alleles across seven HLA genes. Our comorbidity analyses showed that overall AIID and five specific AIIDs were associated with having a psychiatric diagnosis. Our genetic analyses found 81 significant associations between HLA alleles and AIIDs. Lastly, we show connections across AIIDs, psychiatric disorders and infection susceptibility through network analysis of significant HLA associations in these disease classes. Combined, our results include both novel associations as well as replications of previously reported associations in a large sample, and highlight the genetic and epidemiological links between AIIDs and psychiatric disorders.

IL-2-based approaches to Treg enhancement

Immune homeostasis is heavily dependent on the action of regulatory T cells (Tregs) which act to suppress the activation of many immune cell types including autoreactive conventional T cells. A body of evidence has shown that Tregs are intrinsically defective in many common autoimmune diseases, and gene polymorphisms which increase the susceptibility of autoimmune disease development have implicated the interleukin-2 (IL-2) signaling pathway as a key dysregulated mechanism. IL-2 is essential for Treg function and survival, and Tregs are highly sensitive to low levels of this cytokine in their environment. This review will revisit the rationale behind using low-dose IL-2 as a therapy to treat autoimmune diseases and evaluate the outcomes of trials to date. Furthermore, novel engineered IL-2 therapies with increased Treg specificity have shown promise in pre-clinical studies and human clinical trials for some agents have begun. Future studies will determine whether low-dose IL-2 or engineered IL-2 therapies can change the course of autoimmune and inflammatory diseases in patients.

Finding the Needle in the Haystack: Serological and Urinary Biomarkers in Behçet's Disease: A Systematic Review

Urinary and serological markers play an essential role in the diagnostic process of autoimmune diseases. However, to date, specific and reliable biomarkers for diagnosing Behçet's disease (BD) are still lacking, negatively affecting the management of these patients. To analyze the currently available literature on serological and urinary BD biomarkers investigated in the last 25 years, we performed a systematic literature review using the Population, Intervention, Comparison, and Outcomes (PICO) strategy. One hundred eleven studies met the eligibility criteria (6301 BD patients, 5163 controls). Most of them were retrospective, while five (5%) were prospective. One hundred ten studies (99%) investigated serological biomarkers and only two (2%) focused on urinary biomarkers. One hundred three studies (93%) explored the diagnostic potential of the biomolecules, whereas sixty-two (56%) tested their effect on disease activity monitoring. Most articles reported an increase in inflammatory markers and pro-oxidant molecules, with a decrease in antioxidants. Promising results have been shown by the omics sciences, offering a more holistic approach. Despite the vast number of investigated markers, existing evidence indicates a persistent gap in BD diagnostic/prognostic indices. While new steps have been taken in the direction of pathogenesis and disease monitoring, international efforts for the search of a diagnostic marker for BD are still needed.

＜Editors' Choice＞ Myelodysplastic syndrome with trisomy 8 presenting periodic fever and multiple MEFV gene variants outside exon 10: a case report

Myelodysplastic syndrome is associated with the development of autoinflammatory conditions, such as recurrent fever, polymyalgia, arthralgia, and erythema. Trisomy 8 is a common chromosomal abnormality in patients with myelodysplastic syndrome. Myelodysplastic syndrome with trisomy 8 involves autoinflammatory conditions, especially Behçet's disease-like symptoms with intestinal mucosal damage. MEFV variants, particularly those in exon 10, are pathogenic in familial Mediterranean fever, the most common autoinflammatory disease, presenting typical symptoms such as periodic fever and pleuritis/pericarditis/peritonitis. MEFV variants outside exon 10 are common in Japanese patients with familial Mediterranean fever and are associated with atypical symptoms, including myalgia and erythema. MEFV variants in myelodysplastic syndrome with trisomy 8 have rarely been investigated, although myelodysplastic syndrome with trisomy 8 might develop autoinflammatory conditions similar to those in familial Mediterranean fever. We encountered a 67-year-old man who had myelodysplastic syndrome with trisomy 8 and multiple MEFV variants outside exon 10. He presented with periodic fever, as well as chest/abdominal pain, myalgia, and erythema, although the symptoms did not fulfill the diagnostic criteria of familial Mediterranean fever. We discussed the possibility that these symptoms are modified by MEFV variants outside exon 10 in myelodysplastic syndrome with trisomy 8.

ADA2 deficiency (DADA2) misdiagnosed as systemic onset juvenile idiopathic arthritis in a child carrying a novel compound heterozygous ADA2 mutation: a case report

BACKGROUND

The deficiency of adenosine deaminase 2 (DADA2) is caused by an autosomal recessive bi-allelic loss-of-function mutation in the adenosine deaminase 2 (ADA2) gene. DADA2 is a monogenic inherited autoinflammatory disorder characterized by early-onset vasculopathy for which the symptoms range from skin lesions to very severe multiorgan involvement, including life-threatening ischemia and/or hemorrhagic strokes. Owing to the diversity of clinical presentation and the absence of suggestive features, differentiating DADA2 from other inflammatory disorders in the early stages of disease presentation is difficult. Here, we describe the case of a 3-year-old boy who had been misdiagnosed for nearly 2 years before he was definitively diagnosed with DADA2.

CASE DESCRIPTION

A previously healthy 3-year-old boy was initially diagnosed with systemic onset juvenile idiopathic arthritis (soJIA) owing to recurrent unprovoked fever and elevated acute phase reactants. He developed intractable hypertension during treatment, which his doctor considered an adverse drug reaction. Monogenic inherited autoinflammatory disorders were not suspected until the patient developed intestinal perforation and ensuing recurrent abdominal pain that coincided with fever. Gene sequence analysis revealed a novel compound heterozygous mutation in ADA2. The ADA2 enzyme activity was almost completely lost in the patient.

CONCLUSIONS

The broad phenotypic spectrum of DADA2 makes early diagnosis challenging. DADA2 should be considered in case of early-onset vasculitis, which is the most common phenotype of DADA2. Early identification and treatment will result in significant improvement of the disease.

An infant with A20 haploinsufficiency presenting with periodic fever syndrome: A case report

A20 haploinsufficiency (HA20) is an early-onset autoinflammatory disease caused by loss-of-function variants of the TNFAIP3 gene, which encodes the protein A20. HA20 is typically characterized by Behçet's disease-like clinical symptoms, and patients usually present with a family history. Herein, we report a case of HA20 in a pediatric patient, presenting with periodic fever, abdominal pain, and vomiting, with no family history. This patient also harbored a novel heterozygous frameshift variant c.677del (p.Pro226LeufsTer2) of TNFAIP3. We initiated treatment with an anti-tumor necrosis factor-α agent that did not induce symptom resolution; we thus administered combination therapy, including prednisolone. Remission was then successfully achieved. We suggest that HA20 should be considered when an autoinflammatory disease is suspected and periodic fever syndrome is present, even in the absence of a family history of HA20 or Behçet's disease-like symptoms.

Current Evidence on Vaccinations in Pediatric and Adult Patients with Systemic Autoinflammatory Diseases

Systemic autoinflammatory diseases (SAIDs) are defined by recurrent febrile attacks associated with protean manifestations involving joints, the gastrointestinal tract, skin, and the central nervous system, combined with elevated inflammatory markers, and are caused by a dysregulation of the innate immune system. From a clinical standpoint, the most known SAIDs are familial Mediterranean fever (FMF); cryopyrin-associated periodic syndrome (CAPS); mevalonate kinase deficiency (MKD); and periodic fever, aphthosis, pharyngitis, and adenitis (PFAPA) syndrome. Current guidelines recommend the regular sequential administration of vaccines for all individuals with SAIDs. However, these patients have a much lower vaccination coverage rates in 'real-world' epidemiological studies than the general population. The main purpose of this review was to evaluate the scientific evidence available on both the efficacy and safety of vaccines in patients with SAIDs. From this analysis, neither serious adverse effects nor poorer antibody responses have been observed after vaccination in patients with SAIDs on treatment with biologic agents. More specifically, no new-onset immune-mediated complications have been observed following immunizations. Post-vaccination acute flares were significantly less frequent in FMF patients treated with colchicine alone than in those treated with both colchicine and canakinumab. Conversely, a decreased risk of SARS-CoV-2 infection has been proved for patients with FMF after vaccination with the mRNA-based BNT162b2 vaccine. Canakinumab did not appear to affect the ability to produce antibodies against non-live vaccines in patients with CAPS, especially if administered with a time lag from the vaccination. On the other hand, our analysis has shown that immunization against Streptococcus pneumoniae, specifically with the pneumococcal polysaccharide vaccine, was associated with a higher incidence of adverse reactions in CAPS patients. In addition, disease flares might be elicited by vaccinations in children with MKD, though no adverse events have been noted despite concurrent treatment with either anakinra or canakinumab. PFAPA patients seem to be less responsive to measles, mumps, and rubella-vaccine, but have shown higher antibody response than healthy controls following vaccination against hepatitis A. In consideration of the clinical frailty of both children and adults with SAIDs, all vaccinations remain 'highly' recommended in this category of patients despite the paucity of data available.

NLRP3 leucine-rich repeats control induced and spontaneous inflammasome activation in cryopyrin-associated periodic syndrome

BACKGROUND

The cryopyrin-associated periodic syndromes (CAPS) comprise a group of rare autoinflammatory diseases caused by gain-of-function mutations in the NLRP3 gene. NLRP3 contains a leucine-rich repeats (LRR) domain with a highly conserved exonic organization that is subjected to extensive alternative splicing. Aberrant NLRP3 inflammasome assembly in CAPS causes chronic inflammation; however, the mechanisms regulating inflammasome function remain unclear.

OBJECTIVE

We aimed to elucidate the mechanisms regulating NLRP3-mediated autoinflammation in human disease, characterizing the role of LRR in inflammasome activation.

METHODS

We analyzed sequence read archive data to characterize the pattern of NLRP3 splicing in human monocytes and investigated the role of each LRR-coding exon in inflammasome regulation in genetically modified U937 cells representing CAPS and healthy conditions.

RESULTS

We detected a range of NLRP3 splice variants in human primary cells and monocytic cell lines, including 2 yet-undescribed splice variants. We observe that lipopolysaccharides affect the abundance of certain splice variants, suggesting that they may regulate NLRP3 activation by affecting alternative splicing. We showed that exons 4, 5, 7, and 9 are essential for inflammasome function, both in the context of wild-type NLRP3 activation by the agonist molecule nigericin and in a model of CAPS-mediated NLRP3 inflammasome assembly. Moreover, the SGT1-NLRP3 interaction is decreased in nonfunctional variants, suggesting that alternative splicing may regulate the recruitment of proteins that facilitate inflammasome assembly.

CONCLUSION

These findings demonstrate the contribution of the LRR domain in inflammasome function and suggest that navigating LRR exon usage within NLRP3 is sufficient to dampen inflammasome assembly in CAPS.

Preliminary data revealing efficacy of Streptococcus salivarius K12 (SSK12) in Periodic Fever, Aphthous stomatitis, Pharyngitis, and cervical Adenitis (PFAPA) syndrome: A multicenter study from the AIDA Network PFAPA syndrome registry

Objective

To evaluate the potential role of Streptococcus salivarius K12 (SSK12) in controlling febrile flares in patients with Periodic Fever, Aphthous stomatitis, Pharyngitis, and cervical Adenitis (PFAPA) syndrome. Further aims were to assess the impact of SSK12 on (i) flare duration, (ii) variation in the degree of the highest body temperature during flares, (iii) steroid-sparing effect, and (iv) change of PFAPA accompanying symptoms before and after SSK12 introduction.

Patients and methods

The medical charts from 85 pediatric patients with PFAPA syndrome (49 males and 36 females) enrolled in the AIDA registry and treated with SSK12 for a median period of 6.00 ± 7.00 months in the period between September 2017 and May 2022 were examined. Children recruited had a median time of disease duration of 19.00 ± 28.00 months.

Results

The number of febrile flares significantly decreased comparing the 12 months before [median (IQR), 13.00 (6.00)] and after SSK12 initiation [median (IQR), 5.50 (8.00), p < 0.001]. The duration of fever was significantly reduced from 4.00 (2.00) days to 2.00 (2.00) days [p < 0.001]. Similarly, the highest temperature in°C was found significantly lower in the last follow-up assessment [median (IQR), 39.00 (1.00)] compared to the period prior to SSK12 start [median (IQR), 40.00 (1.00), p < 0.001]. Steroid load (mg/year) of betamethasone (or any equivalent steroid) significantly decreased between 12 months before treatment with SSK12 [median (IQR), 5.00 (8.00) mg/year] and the last follow-up visit [median (IQR), 2.00 (4.00) mg/year, p < 0.001]. The number of patients experiencing symptoms including pharyngitis/tonsillitis (p < 0.001), oral aphthae (p < 0.001) and cervical lymphadenopathy (p < 0.001) significantly decreased following SSK12.

Conclusion

SSK12 prophylaxis given for at least 6.00 months was found to reduce febrile flares of PFAPA syndrome: in particular, it halved the total number per year of fever flares, shortened the duration of the single febrile episode, lowered body temperature by 1°C in the febrile flare, provided a steroid-sparing effect, and significantly reduced the accompanying symptoms related to the syndrome.

Differential diagnostic performance of PET/CT in adult-onset still's disease and lymphoma: a retrospective pilot study

Background

Adult-onset still's disease (AOSD) and lymphoma are the common causes of fever of unknown origin (FUO) and show some similar clinical symptoms. This study aimed to establish a reliable and easy-to-used scoring model based on clinical information, laboratory characteristics and ¹⁸F-fluorodeoxyglucose positron emission tomography/computer tomography (¹⁸F-FDG PET/CT) images for the differential diagnosis of these two diseases.

Methods

A development cohort including 70 AOSD and 37 lymphoma patients was used to establish a scoring model based on the features of PET/CT images. The scoring model was then validated in a validation cohort of 15 AOSD and 12 lymphoma patients. The features of involved bone marrow, spleen, lymph nodes, and other organs or tissues displayed on PET/CT images were compared. Multiple logistics regression and decision tree analysis were used to establish the scoring model.

Results

Four features that could significantly differentiate these two diseases were selected to establish a scoring model discriminating AOSD from lymphoma, including (I) white blood cell (WBC) count ≤10×10⁹/L (1 point); (II) ferritin ≤ upper limit of normal (ULN) (1 point); (III) no abnormal bone marrow metabolism (1 point); (IV) total lesion glycolysis_total (TLG_total) >9.0 (1 point). After decision tree analysis, it showed that a score ≤1 indicates AOSD. A score ≥3 strongly suggested lymphoma, with a sensitivity of 81.1% and specificity of 90.0% in the development cohort, and a sensitivity of 58.3% and specificity of 100% in the validation cohort.

Conclusions

Our scoring model showed good diagnosis performance in distinguishing AOSD from lymphoma.

Case Report: Interindividual variability and possible role of heterozygous variants in a family with deficiency of adenosine deaminase 2: are all heterozygous born equals?

Deficiency of adenosine deaminase 2 (DADA2) is a rare systemic autoinflammatory disease, typically with autosomal recessive inheritance, usually caused by biallelic loss of function mutations in the ADA2 gene. The phenotypic spectrum is broad, generally including fever, early-onset vasculitis, stroke, and hematologic dysfunction. Heterozygous carriers may show related signs and symptoms, usually milder and at an older age. Here we describe the case of two relatives, the proband and his mother, bearing an ADA2 homozygous pathogenic variant, and a heterozygous son. The proband was a 17-year-old boy with intermittent fever, lymphadenopathies, and mild hypogammaglobulinemia. He also had sporadic episodes of aphthosis, livedo reticularis and abdominal pain. Hypogammaglobulinemia was documented when he was 10 years old, and symptoms appeared in his late adolescence. The mother demonstrated mild hypogammaglobulinemia, chronic pericarditis since she was 30 years old and two transient episodes of diplopia without lacunar lesions on MRI. ADA2 (NM_001282225.2) sequencing identified both mother and son as homozygous for the c.1358A>G, p.(Tyr453Cys) variant. ADA2 activity in the proband and the mother was 80-fold lower than in the controls. Clinical features in both patients improved on anti-tumor necrosis factor therapy. An older son was found to be heterozygous for the same mutation post-mortem. He died at the age of 12 years due to a clinical picture of fever, lymphadenitis, skin rash and hypogammaglobulinemia evolving toward fatal multiorgan failure. Biopsies of skin, lymph nodes, and bone marrow excluded lymphomas and vasculitis. Despite being suspected of symptomatic carrier, the contribution of an additional variant in compound heterozygosity, or further genetic could not be ruled out, due to poor quality of DNA samples available. In conclusion, this familiar case demonstrated the wide range of phenotypic variability in DADA2. The search for ADA2 mutations and the assessment of ADA2 activity should be considered also in patients with the association of hypogammaglobulinemia and inflammatory conditions, also with late presentation and in absence of vasculitis. Furthermore, the clinical picture of the deceased carrier suggests a possible contribution of heterozygous pathogenic variants to inflammation.

Ultra-high frequency ultrasound detection of the dermo-epidermal junction: Its potential role in dermatology

Traditional high-frequency ultrasound (HFUS; 20 MHz) is a non-invasive method used to study skin in vivo but is not able to measure skin thickness accurately and to identify the dermal-epidermal junction (DEJ). Ultra-high frequency ultrasound (UHFUS; 70-100 MHz) has sub-millimetre resolution comparable to histology. The aim of this study was to identify, by UHFUS, the DEJ and to describe skin differences in healthy individuals by providing a measure of skin thickness, based on age and gender. We also described the bullous pemphigoid lesion. We enrolled 42 patients divided into 2 groups: A and B. Group A included 32 healthy volunteers aged 22-74 years. Group B consisted of 10 patients with bullous pemphigoid. For each patient in group A, 8 ultrasound (US) clips by 70 MHz probe were performed at forehead, cheek, nose, forearm, abdomen, chest, back and leg. For each patient in group B, 5 US images were acquired at blisters roofs and edges. In each US image, we measured thickness of stratum corneum (α-β), epidermis (α-γ) and epidermis plus dermis (α-δ). In both groups, we found the presence of 4 lines delimiting: the stratum corneum (the layer between α-line and β-line), the epidermis (distance between α- and γ-line), and the boundary between dermis and subcutis (δ-line). The γ-line corresponds to the point of detachment of the bullae. The abdominal α-β layer was thicker in males (p = 0.019) and α-δ thickness at cheeks (p < 0.001), chest (p = 0.007), back (p = 0.025) and forearm (p < 0.001). In females, α-γ thickness of the back was greater (p = 0.005). In old people compared to young, we noticed an increase of α-β layer at forehead and chest (p = 0.014), an increase of α-γ layer at forearm (p = 0.001), back (p = 0.024) and leg (p = 0.010) and an increase of α-δ layer at forehead (p = 0.001) and nose (p = 0.049). UHFUS is an advanced imaging technique that can detect both the DEJ and the boundary between dermis and subcutaneous tissue so that epidermal and dermal thickness can be measured with good accuracy. Regarding gender and age, skin differences obtained with UHFUS were comparable to other non-invasive methods.

The Spectrum of Still's Disease: A Comparative Analysis of Phenotypic Forms in a Cohort of 238 Patients

Still's disease (SD) is a heterogeneous autoinflammatory disorder for which several phenotypes have been described. We conducted a retrospective study to re-evaluate the dichotomous view of the disease, to compare the juvenile and adult forms, and to look for prognostic factors. We collected data from ten French centers, seeking patients with a diagnosis of adult-onset SD (AOSD) or systemic juvenile idiopathic arthritis (sJIA). We identified 238 patients, 152 (64%) of whom had AOSD while 86 (36%) had sJIA. The median age at SD onset was 26.6 years. In patients with identifiable patterns, the course of SD was systemic in 159 patients (74%), chronic in 55 (26%). Sore throat and myalgia were more frequent in patients with AOSD. Abnormal liver tests, serum ferritin and C-reactive protein levels were higher in AOSD group. Fever and skin rash were predictive of complete remission or recovery and high lactate dehydrogenase level was a poor prognosis factor. Symptoms such as splenomegaly, skin rash, high polymorphonuclear neutrophils count and macrophage activation syndrome were predictive of a systemic phenotype. Overall, there were no major differences between sJIA and AOSD. Our results are consistent with the "biphasic" model of an autoinflammatory disease that can progress to chronic arthritis if not treated early.

Steroid hormone catabolites activate the pyrin inflammasome through a non-canonical mechanism

The pyrin inflammasome acts as a guard of RhoA GTPases and is central to immune defenses against RhoA-manipulating pathogens. Pyrin activation proceeds in two steps. Yet, the second step is still poorly understood. Using cells constitutively activated for the pyrin step 1, a chemical screen identifies etiocholanolone and pregnanolone, two catabolites of testosterone and progesterone, acting at low concentrations as specific step 2 activators. High concentrations of these metabolites fully and rapidly activate pyrin, in a human specific, B30.2 domain-dependent manner and without inhibiting RhoA. Mutations in MEFV, encoding pyrin, cause two distinct autoinflammatory diseases pyrin-associated autoinflammation with neutrophilic dermatosis (PAAND) and familial Mediterranean fever (FMF). Monocytes from PAAND patients, and to a lower extent from FMF patients, display increased responses to these metabolites. This study identifies an unconventional pyrin activation mechanism, indicates that endogenous steroid catabolites can drive autoinflammation, through the pyrin inflammasome, and explains the “steroid fever” described in the late 1950s upon steroid injection in humans.

Magnotti et al. use a chemical screen to identify pyrin inflammasome activators acting primarily on pyrin step 2. Pregnanolone and etiocholanolone, two catabolites of progesterone and testosterone, activate human pyrin in a B30.2-dependent manner. Pyrin-mutated PAAND patients are highly responsive to pregnanolone. These endogenous catabolites could contribute to sterile (auto)inflammation.

Familial Mediterranean Fever and Diet: A Narrative Review of the Scientific Literature

Background: Familial Mediterranean fever (FMF) is an inherited autoinflammatory disease characterized by short acute attacks, with an as yet unknown cause. Several authors have investigated the role of some foods as potential triggers. This narrative review aims to analyze the correlation between diet and FMF clinical outcomes. Methods: The review was carried out following PRISMA statement guidelines, including all cross-sectional, case-crossover, and trial studies written in English and conducted between 1974 and 2022. Results: Overall, 642 records were identified through PubMed/MEDLINE (292) and Scopus (350), and seven studies were included: three out of seven (43%) studies evaluated FMF attack recurrence or time between consumption of high-fat foods and FMF attacks, while another three (43%) articles variously assessed FMF severity, and one (14%) evaluated the distribution of MEFV mutations. Conclusions: To date, conflicting results have been reported about fatty and salty food intake and FMF attack recurrence. Moreover, some authors have suggested a possible role of wheat. Finally, a diet rich in antioxidants and supplements with an anti-inflammatory effect could partially reduce symptoms and improve the well-being of FMF patients. Nevertheless, no conclusive data could be drawn about the impact of diet in FMF symptom triggering, and further studies are required to clarify this putative association.

VEXAS Syndrome: A Novelty in MDS Landscape

Fever, inflammation and vacuoles in hematopoietic cells represent the main features associated with VEXAS syndrome, a new prototype of autoinflammatory disorders genetically characterized by somatic mutation of the UBA1 gene which encodes the enzyme1-activating enzyme (E1) required for ubiquitin signaling. Described very recently, patients with VEXAS syndrome present a systemic autoinflammatory syndrome associated with hematological impairments, especially cytopenias whose pathophysiology is mainly non-elucidated. Initially diagnosed in elderly male patients, VEXAS syndrome was frequently associated with a diagnosis of myelodysplastic syndromes (MDS) leading the medical community to first consider VEXAS syndrome as a new subtype of MDS. However, since the first description of VEXAS patients in 2021, it appears from the multitude of case reports that MDS associated with VEXAS are different from the classically described MDS.

Modulation of Autoimmune and Autoinflammatory Diseases by Gasdermins

Autoimmune diseases and autoinflammatory diseases are two types of the immune system disorders. Pyroptosis, a highly inflammatory cell death, plays an important role in diseases of immune system. The gasdermins belong to a pore-forming protein gene family which are mainly expressed in immune cells, gastrointestinal tract, and skin. Gasdermins are regarded as an executor of pyroptosis and have been shown to possess various cellular functions and pathological effects such as pro-inflammatory, immune activation, mediation of tumor, etc. Except for infectious diseases, the vital role of gasdermins in autoimmune diseases, autoinflammatory diseases, and immune-related neoplastic diseases has been proved recently. Therefore, gasdermins have been served as a potential therapeutic target for immune disordered diseases. The review summarizes the basic molecular structure and biological function of gasdermins, mainly discusses their role in autoimmune and autoinflammatory diseases, and highlights the recent research on gasdermin family inhibitors so as to provide potential therapeutic prospects.

Profile of circulating extracellular vesicles microRNA correlates with the disease activity in granulomatosis with polyangiitis

Granulomatosis with polyangiitis is a chronic systemic inflammation of small vessels characterized by circulating anti-proteinase 3 antibodies. MicroRNAs are short transcripts specifically inhibiting protein translation. Neutrophils can release extracellular vesicles (EVs). In this study, we characterized profile of microRNA trafficked by EVs in GPA. Fifty patients with GPA were enrolled in the study, 25 at acute phase and 25 in remission. EVs were isolated from the blood serum, characterized by their number, size distribution. Following unbiased screening for microRNA expression, differentially expressed candidates were measured by quantitative real-time PCR. Circulating DNA-myeloperoxidase complexes and apoptosis-related transcripts in peripheral blood neutrophils were quantified. We identified four differentially expressed microRNAs from EVs in granulomatosis with polyangiitis (GPA). MirRs-223-3p, 664a-3p, and 200b-3p were overexpressed and miR-769-5p suppressed in the disease. A distinction between GPA and healthy controls was the best for miR-223-3p, whereas miR-664a-3p discriminated between active vs. remission of GPA. Correct classification of the disease based on multivariate discriminant analysis was between 92% for acute phase and 85% for all study participants. Bioinformatics tools identified genes transcripts potentially targeted by the microRNAs belonging to pathways of focal adhesion, mTOR signaling and neutrophil extracellular traps formation. Two microRNAs positively correlating with the disease activity were involved in neutrophil extracellular traps formation and apoptosis inhibition. A comprehensive characteristics of microRNAs trafficked in bloodstream inside EVs correlates well with our understanding of the mechanisms of GPA and suggests the importance of EVs in progression of the disease.

Pathophysiological functions of self-derived DNA

Inflammation plays indispensable roles in building the immune responses such as acquired immunity against harmful pathogens. Furthermore, it is essential for maintaining biological homeostasis in ever-changing conditions. Pattern-recognition receptors (PRRs) reside in cell membranes, endosomes or cytoplasm, and function as triggers for inflammatory responses. Binding of pathogen- or self-derived components, such as DNA, to PRRs activates downstream signaling cascades, resulting in the production of a series of pro-inflammatory cytokines and type I interferons (IFNs). While these series of responses are essential for host defense, the unexpected release of DNA from the nucleus or mitochondria of host cells can lead to autoimmune and autoinflammatory diseases. In this review, we focus on DNA-sensing mechanisms via PRRs and the disorders and extraordinary conditions caused by self-derived DNA.

Clinical and Genetic Features of Chinese Adult Patients With Chronic Non-Bacterial Osteomyelitis: A Single Center Report

Objectives

Chronic non-bacterial osteomyelitis (CNO) is a rare polygenic autoinflammatory bone disease. We aimed to characterize the clinical manifestations and gene variants of Chinese adult patients with CNO.

Methods

By reviewing data of all CNO patients being diagnosed and followed up at the Center for Adult Autoinflammation Diseases, Department of Rheumatology, Peking Union Medical College Hospital, clinical and genetic features of these patients were evaluated and concluded.

Results

The median age of disease onset was 19 (6-64) years old, and adult-onset was observed in 6 (60%) patients. The mean time of diagnosis delay was 92 ± 78 months. The common symptoms were bone pain (10, 100%), fever (9, 90%), and arthritis (6, 60%). In total, there were 54 skeletal lesions, and each patient had no less than 2 lesions. The most frequently affected sites included lower limbs (20.5%), mandible, vertebrae and pelvis (17.5%, separately). Variants of 4 genes were detected in our study including COL1A1, PSTPIP1, LRP5 and CLCN7. In seven patients who were treated with combination therapy containing tumor necrosis factor (TNF) α inhibitors, five (55.6%) had a complete response and 2 (44.4%) had a partial response.

Conclusion

This is the first and largest case series of CNO in the Chinese adult patients. Four novel genetic mutations potentially associated with CNO were identified. Notably, CNO should be considered in the differential diagnosis of adult patients with long disease course and recurrent multifocal osteomyelitis of unknown cause, and these patients might benefit from combination therapy containing TNFα inhibitors.

Repeated Necrotizing Lymphadenitis with MEFV Gene Mutations

We herein report a 36-year-old man with repeated necrotizing lymphadenitis due to MEFV gene mutations. The patient's chief complaints were a fever and painful cervical lymphadenopathy. We diagnosed him with necrotizing lymphadenitis based on the pathological findings of the lymph nodes and the exclusion of other differential diseases. The same episode recurred four times. We speculated the involvement of autoinflammatory backgrounds and detected MEFV gene mutations of E148Q (homo), P369S, and R408Q. Considering the elevation of interleukin-18, these mutations probably played roles in the repeated necrotizing lymphadenitis.