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Objective: To identify the molecular basis of a severe systemic autoinflammatory disorder (SAID) and define its main phenotypic features, and to functionally assess the sequence variations identified in LYN, a gene encoding a nonreceptor tyrosine kinase. Methods: We used targeted next‐generation sequencing and in vitro functional studies of Lyn phosphorylation state and Lyn‐dependent NF‐κB activity after expression of recombinant Lyn isoforms carrying different sequence variations. Results: We identified a de novo LYN variation (p.Tyr508His) in a patient presenting since birth with recurrent fever, chronic urticaria, atopic dermatitis, arthralgia, increased inflammatory biomarkers, and elevated plasma cytokine levels. We studied the consequences on Lyn phosphorylation state of the p.Tyr508His variation and of the 2 LYN variations reported so far (p.Tyr508Phe and p.Tyr508*), and found that all 3 variations prevent phosphorylation of residue 508 and lead to autophosphorylation of Tyr397. Additionally, these 3 LYN variations activate the NF‐κB pathway. These results show a gain‐of‐function effect of the variations involving Tyr508 on Lyn activity. Conclusion: This study demonstrates the pathogenicity of the first 3 LYN variations identified in SAID patients and delineates the phenotypic spectrum of a disease entity characterized by severe, early‐onset, systemic inflammatory disease affecting neonates with no family history of SAID. All 3 LYN variations affect the same tyrosine residue located in the C‐terminus of Lyn, thereby demonstrating the critical role of this residue in the proper regulation of Lyn activity in humans. [ABSTRACT FROM AUTHOR]

Objective To identify the molecular basis of a systemic autoinflammatory disorder (SAID) evocative of TNF receptor-associated periodic syndrome (TRAPS). Methods (i) Deep next generation sequencing (NGS) through a SAID gene panel; (ii) variant allele distribution in peripheral blood subpopulations; (iii) in silico analyses of mosaic variants using TNF receptor superfamily 1A (TNFRSF1A) crystal structure; (iv) review of the very rare TNFRSF1A mosaic variants reported previously. Results In a 36-year-old man suffering from recurrent fever for 12 years, high-depth NGS revealed a TNFRSF1A mosaic variant, c.176G>A p.(Cys59Tyr), which Sanger sequencing failed to detect. This mosaic variant displayed a variant allele fraction of 14% in whole blood; it affects both myeloid and lymphoid lineages. p.(Cys59Tyr), a recurrent germline pathogenic variant, affects a crucial cysteine located in the first cysteine-rich domain (CRD1) and involved in a disulphide bridge. Introduction of a tyrosine at this position is expected to disrupt the CRD1 structure. Review of the three previously reported TNFRSF1A mosaic variants revealed that they are all located in a small region of CRD2 and that germinal cells can be affected. Conclusion This study expands the localization of TNFRSF1A mosaic variants to the CRD1 domain. Noticeably, residues involved in germline TNFRSF1A mutational hot spots can also be involved in post-zygotic mutational events. Including our study, only four patients have been thus far reported with TNFRSF1A mosaicism, highlighting the need for a high-depth NGS-based approach to avoid the misdiagnosis of TRAPS. Genetic counselling has to consider the potential occurrence of TNFRSF1A mosaic variants in germinal cells. [ABSTRACT FROM AUTHOR]

Urticarial lesions are observed in both cutaneous and systemic disorders. Familial forms of urticarial syndromes are rare and can be encountered in systemic autoinflammatory diseases. We sought to investigate a large family with dominantly inherited chronic urticarial lesions associated with hypercytokinemia. We performed a genetic linkage analysis in 14 patients from a 5-generation family, as well as whole-exome sequencing, cytokine profiling, and transcriptomic analyses on samples from 2 patients. The identified candidate protein was studied after in vitro expression of the corresponding normal and mutated recombinant proteins. An unsupervised proteomic approach was used to unveil the associated protein network. The disease phenotype of the most affected family members is characterized by chronic urticarial flares associated with extremely high plasma levels of proinflammatory (IL-1β, IL-6, and TNF-α) and anti-inflammatory (IL-10 and IL-1 receptor antagonist [IL-1RA]) cytokines, with no secondary organ dysfunction, no susceptibility to infections, no fever, and normal C-reactive protein levels. Monocyte transcriptomic analyses identified an immunotolerant profile in the most affected patient. The affected family members carried a loss-of-function mutation in RNF213 that encodes mysterin, a protein with a poorly known physiologic role. We identified the deubiquitinase CYLD, a major regulator of inflammation, as an RNF213 partner and showed that CYLD expression is inhibited by wild-type but not mutant RNF213. We identified a new entity characterized by chronic urticarial lesions associated with a clinically blunted hypercytokinemia. This disease, which is due to loss of function of RNF213, reveals mysterin's key role in the complex molecular network of innate immunity. [ABSTRACT FROM AUTHOR]

Objective Cryopyrin-associated periodic syndrome (CAPS) is a rare but treatable inherited autoinflammatory condition including familial cold autoinflammatory syndrome (FCAS), Muckle–Wells syndrome (MWS) and chronic infantile neurologic cutaneous articular syndrome (CINCA). Our objective was to describe the main features of CAPS AA amyloidosis (AA-CAPS) associated and the efficacy of IL-1 inhibitors in this indication. Methods Retrospective study in France associated with a systematic literature review. Results Eighty-six patients were identified: 23 new French cases and 63 from the literature, with a median age at amyloidosis diagnosis of 39 years old. CAPS subtypes were MWS (n  = 62), FCAS (n  = 9), frontier forms between MWS and FCAS (n  = 12) and between CINCA and MWS (n  = 3). NLRP3 had been sequenced in 60 patients (70%) and the most frequent mutation was R260W (60%). Three AA-CAPS patients displayed somatic NLRP3 mutations. Death occurred in 35 patients (41%), none of whom having ever received IL-1 inhibitors. Twenty-eight patients (33%) received IL-1 inhibitors, with a >50% decrease in proteinuria in 89% of cases. Conclusion AA amyloidosis can occur in nearly all CAPS subtypes. IL-1 inhibitors are effective, underlining the necessity of an early diagnosis of CAPS in order to start this treatment as soon as possible among AA-CAPS patients. [ABSTRACT FROM AUTHOR]

TCF4 haploinsufficiency by deletions, truncating variants or loss‐of‐function missense variants within the DNA‐binding and protein interacting bHLH domain causes Pitt‐Hopkins syndrome (PTHS). This neurodevelopmental disorder (NDD) is characterized by severe intellectual disability (ID), epilepsy, hyperbreathing and a typical facial gestalt. Only few aberrations of the N‐terminus of TCF4 were associated with milder or atypical phenotypes. By personal communication and searching databases we assembled six cases with the novel, recurrent, de novo missense variant c.1165C > T, p.(Arg389Cys) in TCF4. This variant was identified by diagnostic exome or panel sequencing and is located upstream of the bHLH domain. All six individuals presented with moderate to severe ID with language impairment. Microcephaly occurred in two individuals, epilepsy only in one, and no breathing anomalies or myopia were reported. Facial gestalt showed some aspects of PTHS but was rather non‐specific in most individuals. Interestingly, the variant is located within the AD2 activation domain next to a highly conserved coactivator‐recruitment motif and might alter interaction with coactivator proteins independently from the bHLH domain. Our findings of a recurrent missense variant outside the bHLH domain in six individuals with an ID phenotype overlapping with but not typical for PTHS delineate a novel genotype–phenotype correlation for TCF4‐related NDDs. [ABSTRACT FROM AUTHOR]

Heterozygous deletions are searched using semiquantitative fluorescent multiplex PCR (QMF-PCR) and characterized in patients of Waardenburg syndrome Types 2 and 4. Genes removed by deletions showed neurological phenotypes.

Coenzyme [Q.sub.10] (Co[Q.sub.10]) plays a pivotal role in oxidative phosphorylation (OXPHOS), as it distributes electrons among the various dehydrogenases and the cytochrome segments of the respiratory chain. We have identified [...]

Objectives TNF receptor-1-associated periodic syndrome (TRAPS) is a rare autosomal dominant autoinflammatory disorder associated with mutations in the TNF receptor super family 1 A (TNFRSF1A) gene. AA amyloidosis (AA) is the most severe complication of TRAPS. To study the occurrence and prognosis of AA in TRAPS, we conducted a retrospective study of all French cases and a systematic literature review. Methods This case series includes TRAPS patients followed by our centre from 2000 to 2020 presenting with histologically confirmed AA. We conducted a systematic literature review on the PubMed and EMBASE databases for articles published up to February 2021 following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and using the keywords: amyloidoisis, amyloid, TNF receptor-associated periodic syndrome, TNF receptor-associated periodic syndrome, tumor necrosis factor receptor-associated periodic syndrome, TRAPS, TNFRSF1A , familial hibernian fever and hibernian familial fever. Results A total of 41 TRAPS with AA were studied: three new patients and 38 cases from the literature. AA diagnosis preceded that of TRAPS in 96% of cases, and 17/36 (47%) required renal replacement therapy. Death occurred in 5/36 (14%) with a median follow-up of 23 months. Effect of biologics on AA were available for 21 regimens in 19 patients: 10 improved renal function, seven stabilized and four worsened. Four patients (36% of transplanted patients) relapse AA on kidney graft (only one under etanercept). Conclusion TRAPS is revealed by AA in most cases. Therefore, clinical features of TRAPS should be screened for in AA patients. IL-1 antagonist can help to normalize inflammation and to preserve renal function. [ABSTRACT FROM AUTHOR]

Background: Terminal deletions of the long arm of chromosome 7 are well known and frequently associated with syndromic holoprosencephaly due to the involvement of the SHH (aliases HHG1, SMMCI, TPT, TPTPS, and MCOPCB5) gene region. However, interstitial deletions including CNTNAP2 (aliases Caspr2, KIAA0868, and NRXN4) and excluding the SHH region are less common. Methods: We report the clinical and molecular characterization associated with pure 7q35 and 7q35q36.1 deletion in two unrelated patients as detected by oligonucleotide‐based array‐CGH analysis. Results: The common clinical features were abnormal maternal serum screening during first‐trimester pregnancy, low occipitofrontal circumference at birth, hypotonia, abnormal feet, developmental delay, impaired language development, generalized seizures, hyperactive behavior, friendly personality, and cranio‐facial dysmorphism. Both deletions occurred de novo and sequencing of CNTNAP2, a candidate gene for epilepsy and autism showed absence of mutation on the contralateral allele. Conclusion: Combined haploinsufficiency of GALNTL5 (alias GalNAc‐T5L), CUL1, SSPO (aliases SCO‐spondin, KIAA0543, and FLJ36112), AOC1(alias DAO), RHEB, and especially KMT2C (alias KIAA1506 and HALR) with monoallelic disruption of CNTNAP2 may explain neurologic abnormalities, hypotonia, and exostoses. Haploinsufficiency of PRKAG2 (aliases AAKG, AAKG2, H91620p, WPWS, and CMH6) and KCNH2 (aliases Kv11.1, HERG, and erg1) genes may be responsible of long QT syndrome observed for one patient. [ABSTRACT FROM AUTHOR]

Background & Aims: Secondary to tumour necrosis factor‐alpha induced protein 3 (TNFAIP3) mutations, A20 haploinsufficiency (HA20) is a recently described autoinflammatory disease with clinical features similar to those of Behçet's and Crohn's diseases but with a constantly expanding clinical spectrum. Here, we describe HA20 liver involvement in three new patients from the same family. Methods: We retrospectively assessed clinical, biological and/or histological findings for eight patients over three generations of the same family with heterozygous mutations in the TNFAIP3 gene (c.259C > T, p.Arg87*). Results: The eight patients exhibited the following: aphthous ulcers (8/8, bipolar in 7), autoimmune features (6/8, including 5 with definitive autoimmune disease diagnoses, ie, type I diabetes, Hashimoto thyroiditis, pernicious anaemia, and/or 5 with antinuclear antibodies ≥320), pustulosis/folliculitis (5/8), abdominal pain (4/8), arthralgia (3/8), enlarged cervical lymph nodes (3/8) and pericarditis (1/8). In addition, three patients (twin sisters and their grandmother aged 23 and 70 years, respectively) exhibited persistent mild hepatic cytolysis associated with splenomegaly (n = 3), hepatomegaly (n = 1) and/or liver atrophy (n = 1) on echography. We could not detect any other causes of chronic liver diseases. Liver biopsies from three patients displayed hepatic fibrosis, hepatocyte injury and/or CD4+/CD8+ T lymphocyte infiltration, and patterns of inflammatory cells and NLRP3 or NF‐κB immunostaining differed from the predominant neutrophil infiltration observed in skin or some digestive tract biopsies. Conclusions: This study reinforces the dual involvement of innate and adaptive immunity in HA20 according to both acute and chronic injury and the organ involved and widens its clinical spectrum to include chronic hepatic involvement. [ABSTRACT FROM AUTHOR]

Introduction: Familial Mediterranean Fever (FMF), the most common monogenic auto‐inflammatory disease, is characterized by recurrent febrile abdominal pain. Helicobacter pylori infection (HPI), one of the most frequent infections worldwide, can mimic an FMF attack. Objectives: Identify FMF patients with HPI in a cohort of French FMF patients and the literature and identify features allowing to distinguish HPI from an FMF attack. Methods: A retrospective study of all HPI cases was performed on the cohort of FMF patients fulfilling the Livneh criteria from the French Reference Center for rare Auto‐Inflammatory Diseases and Amyloidosis (CEREMAIA). A systematic literature review of HPI in FMF patients was conducted according to the PRISMA guidelines. Results: Eight French patients developed HPI, whose symptoms of epigastralgia, diarrhea, anorexia/weight loss, and nausea/vomiting differed from their typical abdominal FMF attacks. A total of 112 FMF patients with HPI have been described in the literature, including 61 adults. Diagnosis of HPI was made by gastroscopy (n = 43), labelled urea test (n = 55) or IgG serology by ELISA (n = 12). When performed, C‐reactive protein was always elevated. Ten cases of interaction between colchicine and antibiotic therapy for HPI (clarithromycin (n = 9) and azithromycin (n = 1)) were reported. Conclusion: We described a total of 120 patients with typical FMF and HPI. When FMF patients develop atypical abdominal symptoms, upper gastrointestinal endoscopy with biopsies is essential to eliminate underlying HPI. Untreated HPI can lead to misdiagnosis of colchicine resistance with inappropriate prescription of an interleukin‐1 inhibitor at a non‐negligible cost. [ABSTRACT FROM AUTHOR]

Background and Objective: Familial Mediterranean fever (FMF) is the most frequent hereditary autoinflammatory disease. Its diagnosis relies on a set of clinical criteria and a genetic confirmation on identification of biallelic pathogenic MEFV variants. MEFV encodes pyrin, an inflammasome sensor. Using a kinase inhibitor, UCN-01, we recently identified that dephosphorylation of FMF-associated pyrin mutants leads to inflammasome activation. The aim of this study was to assess whether quantifying UCN-01-mediated inflammasome activation could discriminate FMF patients from healthy donors (HD) and from patients with other inflammatory disorders (OID).Methods: Real-time pyroptosis and IL-1β secretion were monitored in response to UCN-01 in monocytes from FMF patients (n=67), HD (n=71) and OID patients (n=40). Sensitivity and specificity of the resulting diagnostic tests were determined by receiver operating characteristic curve analyses.Results: Inflammasome monitoring in response to UCN-01 discriminates FMF patients from other individuals. Pyroptosis assessment leads to a fast FMF diagnosis while combining pyroptosis and IL-1β dosage renders UCN-01-based assays highly sensitive and specific. UCN-01-triggered monocytes responses were influenced by MEFV gene dosage and MEFV mutations in a similar way as clinical phenotypes are.Conclusions: UCN-01-based inflammasome assays could be used to rapidly diagnose FMF, with high sensitivity and specificity. [ABSTRACT FROM AUTHOR]

Mevalonate kinase deficiency (MKD) is a rare autosomal recessive autoinflammatory disease that can lead to an inflammatory A amyloidosis (AA). To study the occurrence of AA in MKD patients we performed a systemic review of the literature and described two novel patients. Amyloidosis occurred in 20 MKD patients, renal impairment being always the revealing symptom of AA. Although an accurate prevalence estimation is not possible since exact MKD prevalence is unknown, AA seems rare in MKD (about 6% if we estimate MKD prevalence at 300 patients worldwide). MVK gene study, available in 18 out of the 20 patients, confirmed two pathogenic mutations in all tested individuals. The most frequent genotype was V377I/I268T (n = 9/18). Retrospective search of clinical signs of MKD established, in all patients carrying MVK pathogenic mutations, a disease onset within the first four years of life. Nephrotic syndrome (n = 15), end-stage renal failure (n = 5) or both (n = 8) pointed out kidney amyloidosis. The youngest patient with renal amyloidosis was a European four-year-old girl previously misdiagnosed with PFAPA syndrome. Five patients died of AA amyloidosis despite the use of a biotherapy for two of them; kidney transplant was performed in nine individuals. Colchicine was not effective in any patient. Anti-interleukin-1 anakinra (n = 8), anti TNF etanercept (n = 7) and anti-interleukin 6 tocilizumab (n = 5) treatments were partially effective. Inflammatory A amyloidosis, a rare complication of MKD, can cause death or necessitate kidney transplantation. Early diagnosis and cytokine blocking biotherapy using anti-IL1, anti-TNF or anti-IL6 agents are required to prevent terminal renal failure. [ABSTRACT FROM AUTHOR]

Byline: Ilham. Ratbi, Chafai. Elalaoui, Moal. Dastot-Le, Michel. Goossens, Irina. Giurgea, Abdelaziz. Sefiani Mowat-Wilson syndrome is a mental retardation-multiple congenital anomaly syndrome characterized by a typical facies, developmental delay, epilepsy, [...]

We aimed to explore triggering receptor expressed on myeloid cells-1 (TREM-1) activation in familial Mediterranean fever (FMF), the most frequent monogenic auto-inflammatory disease, through the measurement of its serum soluble form, named sTREM-1. Blood samples from patients with FMF according to Livneh criteria followed in the French FMF national center and carrying two pathogenic MEFV mutations were collected. Serum level of sTREM-1 was assessed using ELISA. Demographic data, presence of FMF attack, association with histologically proven AA amyloidosis, and blood levels of C-reactive protein (CRP), serum amyloid A (SAA) protein, and creatinine were collected. TREM-1 was available in 56 patients (33.9% male, mean age 43 yr); AA amyloidosis was associated in six patients (19.6% in FMF). Mean sTREM-1 level did not differ significantly between patients having an attack or not and there was also no significant correlation between the level of sTREM-1 and CRP and SAA protein. However, the mean rate of sTREM-1 was significantly higher among FMF patients with AA amyloidosis versus without, though the concomitant SAA protein level was normal. Serum level of sTREM-1 was higher in patients with amyloidosis even though the concomitant SAA protein level was normal. sTREM-1 plasma levels could be an accurate tool to specifically identify FMF patients with amyloidosis. [ABSTRACT FROM AUTHOR]

Objectives: Familial Mediterranean fever (FMF) can be complicated by AA amyloidosis (AAA), though it remains unclear why only some patients develop amyloidosis. We examined the gut microbiota composition and inflammatory markers in patients with FMF complicated or not by AAA.Methods: We analysed the gut microbiota of 34 patients with FMF without AAA, 7 patients with FMF with AAA, 19 patients with AAA of another origin, and 26 controls using 16S ribosomal RNA gene sequencing with the Illumina MiSeq platform. Associations between bacterial taxa and clinical phenotypes were evaluated using multivariate association with linear models statistical method. Blood levels of interleukin (IL)-1β, IL-6, tumour necrosis factor-α and adipokines were assessed by ELISA; indoleamine 2,3-dioxygenase (IDO) activity was determined by high-performance liquid chromatography.Results: Compared with healthy subjects, specific changes in faecal microbiota were observed in FMF and AAA groups. Several operational taxonomic units (OTUs) were associated with FMF. Moreover, two OTUs were over-represented in FMF-related AAA compared with FMF without AAA. Additionally, higher adiponectin levels and IDO activity were observed in FMF-related AAA compared with FMF without AAA (p<0.05).Conclusion: The presence of specific changes in faecal microbiota in FMF and in FMF-related AAA suggests that intestinal microorganisms may play a role in the pathogenesis of these diseases. These findings may offer an opportunity to use techniques for gut microbiota manipulation. [ABSTRACT FROM AUTHOR]

Objective: To determine the molecular and cellular bases of autoinflammatory syndromes in a multigenerational French family with Muckle‐Wells syndrome and in a patient originating from Portugal with familial cold autoinflammatory syndrome. Methods: Sequencing of NLRP3 exon 3 was performed in all accessible patients. Microsatellite and whole‐genome single nucleotide polymorphism genotyping was used i) to test the intrafamilial segregation of the identified variant and ii) to look for a founder effect. Functional analyses included the study of i) apoptosis‐associated speck‐like protein containing a CARD (ASC) speck formation in HEK293T cells (stably expressing ASC–green fluorescent protein and pro‐caspase 1‐FLAG) transiently expressing the wild‐type or mutated NLRP3 protein, ii) levels of IL‐1β secreted from transfected THP‐1 cells, and iii) inflammasome‐related gene expression and cytokine secretion from monocytes isolated from patients in crisis (probands from the two families), related patients out of crisis, and from controls. Results: The same heterozygous mutation (c.1322C>T, p.A441V) located in the NACHT domain, segregating with the disease within the first family, was identified in the two families. This mutation was found to be associated with different core haplotypes. NLRP3‐A441V led to increased ASC speck formation and high levels of secreted IL‐1β. Monocyte inflammasome‐related gene expression and cytokine secretion, which were within the normal range in patients out of crisis, were found to be differentially regulated between the two probands, correlating with their phenotypic status. Conclusion: These molecular and cellular findings, which indicate a recurrent mutational event, clearly demonstrate the pathogenicity of the p.A441V missense mutation in NLRP3‐associated autoinflammatory disease and point to the interest of studying patients' primary cells to assess disease activity. [ABSTRACT FROM AUTHOR]

Circulating serum amyloid A (SAA) is increased in various inflammatory conditions. The human SAA protein family comprises the acute phase SAA1/SAA2, known to activate a large set of innate and adaptive immune cells, and the constitutive SAA4. The liver synthesis of SAA1/SAA2 is well-established but there is still an open debate on extrahepatic SAA expression especially in macrophages. We aimed to investigate the ability of human primary monocytes and monocyte-derived macrophages to express SAA1, SAA2 and SAA4 at both the transcriptional and protein levels, as previous studies almost exclusively dealt with monocytic cell lines. Monocytes and derived macrophages from healthy donors were stimulated under various conditions. In parallel with SAA, pro-inflammatory IL1A, IL1B and IL6 cytokine expression was assessed. While LPS alone was non-effective, a combined LPS/dexamethasone treatment induced SAA1 and to a lesser extent SAA2 transcription in human monocytes and macrophages. In contrast, as expected, pro-inflammatory cytokine expression was strongly induced following stimulation with LPS, an effect which was dampened in the presence of dexamethasone. Furthermore, in monocytes polarized towards a pro-inflammatory M1 phenotype, SAA expression in response to LPS/dexamethasone was potentiated; a result mainly seen for SAA1. However, a major discrepancy was observed between SAA mRNA and intracellular protein levels under the experimental conditions used. Our results demonstrate that human monocytes and macrophages can express SAA genes, mainly SAA1 in response to an inflammatory environment. While SAA is considered as a member of a large cytokine network, its expression in the monocytes-macrophages in response to LPS-dexamethasone is strikingly different from that observed for classic pro-inflammatory cytokines. As monocytes-macrophages are major players in chronic inflammatory diseases, it may be hypothesized that SAA production from macrophages may contribute to the local inflammatory microenvironment, especially when macrophages are compactly organized in granulomas as in sarcoidosis. [ABSTRACT FROM AUTHOR]

Pitt‐Hopkins syndrome (PTHS) is a neurodevelopmental disorder characterized by intellectual disability, specific facial features, and marked autonomic nervous system dysfunction, especially with disturbances of regulating respiration and intestinal mobility. It is caused by variants in the transcription factor TCF4. Heterogeneity in the clinical and molecular diagnostic criteria and care practices has prompted a group of international experts to establish guidelines for diagnostics and care. For issues, for which there was limited information available in international literature, we collaborated with national support groups and the participants of a syndrome specific international conference to obtain further information. Here, we discuss the resultant consensus, including the clinical definition of PTHS and a molecular diagnostic pathway. Recommendations for managing particular health problems such as dysregulated respiration are provided. We emphasize the need for integration of care for physical and behavioral issues. The recommendations as presented here will need to be evaluated for improvements to allow for continued optimization of diagnostics and care. [ABSTRACT FROM AUTHOR]

These data prompted us to assess the contribution of I NLRP3 i and I UBA1 i somatic mutations, as well as of the main genes so far involved in SAID patients with cutaneous lesions in SchS pathophysiology. Absence of NLRP3 somatic mutations and VEXAS-related UBA1 mutations in a large cohort of patients with Schnitzler syndrome Schnitzler's syndrome (SchS) is an extremely rare systemic autoinflammatory disease (SAID) characterized by a late onset of urticarial rash, recurrent fever, bone pain, arthralgia, elevated acute-phase reactants, and a monoclonal gammopathy involving IgM chains (classical type) and rarely IgG (variant type). [Extracted from the article]

Inflammasomes are multiprotein complexes nucleating around an NLR (Nucleotide-binding domain and Leucine-rich Repeat containing protein), which regulate the secretion of the pro-inflammatory interleukin (IL)-1β and IL-18 cytokines. Monocytes and macrophages, the main cells expressing the inflammasome genes, adapt to their surrounding microenvironment by a phenotypic polarization towards a pro-inflammatory M1 phenotype that promotes inflammation or an anti-inflammatory M2 phenotype important for resolution of inflammation. Despite the importance of inflammasomes in health and disease, little is known about inflammasome gene expression in relevant human cells and the impact of monocyte and macrophage polarization in inflammasome gene expression. We examined the expression of several members of the NLR, caspase and cytokine family, and we studied the activation of the well-described NLRP3 inflammasome in an experimental model of polarized human primary monocytes and monocyte-derived macrophages (M1/M2 phenotypes) before and after activation with LPS, a well-characterized microbial pattern used in inflammasome activation studies. Our results show that the differentiation of monocytes to macrophages alters NLR expression. Polarization using IFN-γ (M1 phenotype), induces among the NLRs studied, only the expression of NOD2. One of the key results of our study is that the induction of NLRP3 expression by LPS is inhibited in the presence of IL-4+IL-13 (M2 phenotype) at both mRNA and protein level in monocytes and macrophages. Unlike caspase-3, the expression of inflammasome-related CASP1 (encodes caspase-1) and CASP4 (encodes caspase-4) is up-regulated in M1 but not in M2 cells. Interestingly, the presence of LPS marginally influenced IL18 mRNA expression and secretion, unlike its impact on IL1B. Our data provide the basis for a better understanding of the role of different inflammasomes within a given environment (M1 and M2) in human cells and their impact in the pathophysiology of several important inflammatory disorders. [ABSTRACT FROM AUTHOR]

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Clinical history and inappropriate insulin secretion during hypoglycemic episodes permit the diagnosis of hyperinsulinism. We report 2 cases of factitious hyperinsulinism leading to partial pancreatectomy. Case 1 was an 8-year-old girl who presented with severe hypoglycemia and elevated insulin and C-peptide levels. Catheterization of pancreatic veins was performed to localize the excess insulin secretion. Insulinoma was suspected, and partial pancreatectomy was performed. Ten days after surgery, severe hypoglycemia recurred with severely elevated plasma insulin levels (x100) but very low C-peptide plasma levels, suggesting factitious hyperinsulinemia. Hypoglycemic episodes before surgery were provoked by oral sulfonamides; postoperative episodes were caused by parenteral insulin. Falsified prescriptions for sulfonamides and insulin by the mother, a nurse, were found. Case 2 was a 6-month-old girl who presented with seizures and hypoglycemia but had a symptom-free interval of many months afterward. At 2 years of age, repeated hypoglycemic seizures and elevated insulin plasma levels suggested congenital hyperinsulinism. C-peptide plasma level, measured once, was normal, but blood sampling was performed 15 minutes after a hypoglycemic episode. Partial pancreatectomy was performed. Two weeks after surgery, hypoglycemic seizures recurred, and the patient was admitted for pancreatic vein catheterization. This investigation was performed during hypoglycemia and revealed high insulin levels and undetectable C-peptide levels, suggesting factitious hypoglycemia. Insulin/C-peptide ratio analysis is crucial to assess factitious hypoglycemia, although sulfonamide-induced hypoglycemia is not thereby detected. One percent (2 of 250) of all cases of hyperinsulinemic hypoglycemia in our unit have been identified as Munchausen syndrome by proxy. Atypical disease history should raise the question of factitious hypoglycemia. URL: www.pediatrics.org/ cgi/doi/10.1542/peds.2004-2331; hyperinsulinemia, partial pancreatectomy, Munchausen syndrome by proxy, factitious hypoglycemia.