HSP90ß controls NLRP3 autoactivation.

Gain-of-function mutations in NLRP3 are linked to cryopyrin-associated periodic syndromes (CAPS). Although NLRP3 autoinflammasome assembly triggers inflammatory cytokine release, its activation mechanisms are not fully understood. Our study used a functional genetic approach to identify regulators of NLRP3 inflammasome formation. We identified the HSP90ß-SGT1 chaperone complex as crucial for autoinflammasome activation in CAPS. A deficiency in HSP90ß, but not in HSP90α, impaired the formation of ASC specks without affecting the priming and expression of inflammasome components. Conversely, activating NLRP3 with stimuli such as nigericin or alum bypassed the need for SGT1 and HSP90ß, suggesting the existence of alternative inflammasome assembly pathways. The role of HSP90ß was further demonstrated in PBMCs derived from CAPS patients. In these samples, the pathological constitutive secretion of IL-1ß could be suppressed using a pharmacological inhibitor of HSP90ß. This finding underscores the potential of SGT1-HSP90ß modulation as a therapeutic strategy in CAPS while preserving NLRP3's physiological functions.

PSTPIP1-Associated Myeloid-Related Proteinemia Inflammatory (PAMI) Syndrome: A Systematic Review.

PSTPIP1 (proline-serine-threonine phosphatase-interactive protein 1)-associated myeloid-related proteinemia inflammatory (PAMI) syndrome, previously known as Hyperzincemia/Hypercalprotectinemia (Hz/Hc) syndrome, is a recently described, rare auto-inflammatory disorder caused by specific deleterious variants in the PSTPIP1 gene (p.E250K and p.E257K). The disease is characterized by chronic systemic inflammation, cutaneous and osteoarticular manifestations, hepatosplenomegaly, anemia, and neutropenia. Increased blood levels of MRP 8/14 and zinc distinguish this condition from other PSTPIP1-associated inflammatory diseases (PAID). The aim of this systematic review is to provide a comprehensive overview of the disease phenotype, course, treatment, and outcome based on reported cases. This systematic review adheres to the PRISMA guidelines (2020) for reporting. A literature search was performed in Embase, Medline, and Web of Science on 13 October 2022. The quality of the case reports and case series was assessed using the JBI checklists. Out of the 43 included patients with PAMI syndrome, there were 24 females and 19 males. The median age at onset was 3.9 years. The main clinical manifestations included anemia (100%), neutropenia (98%), cutaneous manifestations (74%), osteoarticular manifestations (72%), splenomegaly (70%), growth failure (57%), fever (51%), hepatomegaly (56%), and lymphadenopathy (39%). Systemic inflammation was described in all patients. Marked elevation of zinc and MRP 8/14 blood levels were observed in all tested patients. Response to treatment varied and no consistently effective therapy was identified. The most common therapeutic options were corticosteroids (N = 30), anakinra (N = 13), cyclosporine A (N = 11), canakinumab (N = 6), and anti-TNF (N = 14). Hematopoietic stem cell transplantation has been recently reported to be successful in five patients. Our review highlights the key characteristics of PAMI syndrome and the importance of considering this disease in the differential diagnosis of patients presenting with early-onset systemic inflammation and cytopenia.

New Dominant-Negative IL6ST Variants Expand the Immunological and Clinical Spectrum of GP130-Dependent Hyper-IgE Syndrome.

Patients with autosomal dominant (AD) hyper-IgE syndrome (HIES) suffer from a constellation of manifestations including recurrent bacterial and fungal infections, severe atopy, and skeletal abnormalities. This condition is typically caused by monoallelic dominant-negative (DN) STAT3 variants. In 2020, we described 12 patients from eight kindreds with DN IL6ST variants resulting in a new form of AD HIES. These variants encoded truncated GP130 receptors, with intact extracellular and transmembrane domains, but lacking the intracellular recycling motif and the four STAT3-binding residues, resulting in an inability to recycle and activate STAT3. We report here two new DN variants of IL6ST in three unrelated families with HIES-AD. The biochemical and clinical impacts of these variants are different from those of the previously reported variants. The p.(Ser731Valfs*8) variant, identified in seven patients from two families, lacks the recycling motif and all the STAT3-binding residues, but its levels on the cell surface are only slightly increased and it underlies mild biological phenotypes with variable clinical expressivity. The p.(Arg768*) variant, identified in a single patient, lacks the recycling motif and the three most distal STAT3-binding residues. This variant accumulates at the cell surface and underlies severe biological and clinical phenotypes. The p.(Ser731Valfs*8) variant shows that a DN GP130 expressed at near normal levels on the cell surface can underlie heterogeneous clinical presentations, ranging from mild to severe. The p.(Arg768*) variant demonstrates that a truncated GP130 protein retaining one STAT3-binding residue can underlie severe HIES.

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.

[Adenosine deaminase 2 deficiency: a disease with multiple presentations]. / Déficit en adénosine désaminase 2 : une maladie aux présentations multiples.

Adenosine deaminase 2 deficiency (DADA2) is a genetic auto- inflammatory disease that most often presents in childhood, but that can also have a late onset in adulthood. It is characterized by vasculitis, mainly of the skin and nervous system most often in the form of a stroke, associated to immunodeficiency and cytopenias. The diagnosis is made by measuring adenosine deaminase 2 (ADA2) enzymatic activity and confirming the presence of mutations in the ADA2 gene by genetic testing. The treatment of choice for the inflammatory phenotype is the early administration of anti-TNFa to avoid the risk of major neurological disabilities. In the case of severe hematological involvement, hematopoietic stem cell transplantation is the only curative treatment currently available.

Le déficit en adénosine désaminase 2 (DADA2) est une maladie génétique auto-inflammatoire qui se manifeste le plus souvent à l'âge pédiatrique mais qui peut également débuter à l'âge adulte. Il se caractérise par une atteinte vasculitique responsable d'altérations cutanées et d'AVC associée à une immunodéficience et des cytopénies. Le diagnostic de DADA2 est posé par le dosage de l'activité de l'adénosine désaminase 2 (ADA2) et la confirmation par un test génétique d'une mutation dans le gène ADA2. Le traitement de choix du phénotype inflammatoire repose sur l'administration précoce d'anti-TNFα pour éviter la survenue d'un handicap neurologique majeur. En cas d'atteinte hématologique sévère, la greffe de cellules souches hématopoïétiques est le seul traitement curatif actuellement disponible.

Chronic Nonbacterial Osteomyelitis in Children.

Chronic nonbacterial osteomyelitis (CNO) is an auto-inflammatory bone disorder with a wide spectrum of clinical manifestations, from unifocal to multifocal lesions. When it manifests with multifocal lesions, it is also referred to as chronic recurrent multifocal osteomyelitis (CRMO). CNO/CRMO can affect all age groups, with the pediatric population being the most common. Patients may present with systemic inflammation, but there is no pathognomonic laboratory finding. Magnetic resonance imaging (MRI) is the gold standard radiological tool for diagnosis. In the absence of validated diagnostic criteria, CNO/CRMO remains an exclusion diagnosis. Bone biopsy does not show a specific disease pattern, but it may be necessary in unifocal or atypical cases to differentiate it from malignancy or infection. First-line treatments are non-steroidal anti-inflammatory drugs (NSAIDs), while bisphosphonates or TNF-α blockers can be used in refractory cases. The disease course is unpredictable, and uncontrolled lesions can complicate with bone fractures and deformations, underlying the importance of long-term follow-up in these patients.

[Newborn screening for severe T and B lymphocyte deficiencies in Switzerland]. / Pédiatrie - Dépistage des nouveau-nés en Suisse pour les déficiences sévères à lymphocytes T et B.

Severe Combined Immunodeficiency (SCID) is one of the most severe forms of Primary Immunodeficiencies (PID) and leads to a potentially fatal course of disease without early and definitive treatment. Adequate management, from the first days of life, can improve the survival and outcome of patients with SCID. This can be achieved through newborn screening (NBS) based on the measurement of T-cell receptor excision circles (TREC). Already present in many countries, this NBS test was introduced in Switzerland in January 2019 on a pilot phase. In addition to the assessment of TRECs, the measurement of kappa recombinant excision circles (KREC) has also been introduced at the same time and allows the identification of severe forms of PID characterized by profound B cell lymphopenia.

Le déficit immunitaire combiné sévère (DICS) fait partie des formes sévères d'immunodéficience primaire (IDP) avec un tableau clinique fatal sans traitement précoce et définitif, comme la transplantation des cellules souches hématopoïétiques. Une prise en charge adéquate dès les premiers jours de vie va permettre d'améliorer le devenir des patients avec DICS. Une meilleure prise en charge est devenue possible grâce au dépistage néonatal basé sur la mesure des cercles d'excision des récepteurs des cellules T. Ce test a été introduit en Suisse dans une phase pilote à partir de janvier 2019, avec un dépistage supplémentaire via le dosage des cercles d'excision des recombinants Kappa, qui permet d'identifier des formes graves d'IDP se manifestant surtout par une lymphopénie B profonde.

Increased Prevalence of NLRP3 Q703K Variant Among Patients With Autoinflammatory Diseases: An International Multicentric Study.

Background: The NLRP3 inflammasome has been recognized as one of the key components of innate immunity. Gain-of-function mutations in the exon 3 of NLRP3 gene have been implicated in inflammatory diseases suggesting the presence of functionally important sites in this region. Q703K (c.2107C>A, p.Gln703Lys, also known in the literature as Q705K) is a common variant of NLRP3, that has been considered to be both clinically unremarkable or disease-causing with a reduced penetrance. Objectives: We aimed to investigate the potential genetic impact of the NLRP3 variant Q703K in patients with recurrent fever presenting with two autoinflammatory diseases: PFAPA (periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis) and CAPS (cryopyrin-associated periodic syndrome), as well as with undefined autoinflammatory disease (uAID). Methods: This is an international multicentric observational retrospective study characterizing the clinical phenotype of patients presenting with recurrent fever suspected to be of auto-inflammatory origin and where the Q703K NLRP3 variant was found. Monocytes of parents of 6 Q703K+ PFAPA patients were studied and levels of pro-inflammatory cytokines produced by monocytes of Q703K+ and Q703K- parents have been compared by ELISA. Results: We report 42 patients with the Q703K NLRP3 genetic variant: 21 were PFAPA patients, 6 had a CAPS phenotype, and 15 had an uAID. The phenotypes of PFAPA, CAPS and uAID were quite similar between Q703K positive and negative patients with the exception of increased prevalence of pharyngitis in the Q703K positive CAPS population compared to the negative one. The in vitro production of IL-1ß was not significantly different between Q703K+ and Q703K- monocytes from asymptomatic parents. Conclusion: The evidence we report in our study shows an increased prevalence of NLRP3 Q703K in patients with autoinflammatory diseases, suggesting an association between the Q703K variant and the risk of PFAPA, CAPS and uAID syndromes. However, we did not show a functional effect of this mutation on the inflammasome basal activity.

Interleukin-1 Blockade in Systemic Juvenile Idiopathic Arthritis.

Systemic juvenile idiopathic arthritis (sJIA) is a severe disorder now linked more to autoinflammation than to autoimmunity. Clinical and laboratory evidence support the pathogenetic role of interleukin-1 (IL-1), and blockade of this cytokine has proved to be very effective in the treatment of sJIA. There are now several agents that block IL-1 available on the market. This article reviews the efficacy and safety of these drugs for the treatment of sJIA on the basis of published data, and offers the current view on treating sJIA according to its different phenotypes. There are no head to head trials among the different IL-1 inhibitors, and although efficacy has been demonstrated for all of them, it is still unknown which one would be more appropriate for which particular situation. The presence of synovitis in addition to active systemic features might be relevant for these choices. In addition, complications such as macrophage activation syndrome can be important since, on one hand, it has been associated with biologic therapy administration and, on another, there have been some reports of this complication being treated with anti-IL-1. Current recommendations by the American College of Rheumatology are now outdated, and new ones are being prepared. In the meantime, basic and clinical research is advancing in order to identify new treatment targets and to evaluate the different protocols currently in use.

[Systemic juvenile onset idiopathic arthritis and adult onset still disease]. / Arthrite juvénile systémique et maladie de Still de l'adulte.

Still's disease is a rare multifactorial disease associated with systemic inflammation. Systemic-onset juvenile idiopathic arthritis and adult-onset Still's disease are both pediatric and respectively adult forms of the disease with a cut-off age of 16 years. The disease is characterized by the following features : hectic fever > 39° C, arthralgia or arthritis, rash, neutrophilia and systemic inflammation. The prognosis of the disease is functional and vital. The evolution over time is variable : regression, evolution by relapses with regression at term and chronic joint evolution. This focus describes the two forms of the disease, their complications and the therapeutic options.

La maladie de Still est une maladie rare multifactorielle et associée à une inflammation systémique. L'arthrite juvénile idiopathique systémique et la maladie de Still de l'adulte sont les deux formes respectivement pédiatrique et adulte de la maladie, avec un âge seuil de 16 ans. Elle est caractérisée par les quatre éléments suivants : fièvre hectique > 39° C, arthralgies ou arthrites, éruption cutanée, neutrophilie et inflammation systémique. Le pronostic de la maladie est fonctionnel et vital. L'évolution au cours du temps est variable : régression, évolution par poussées avec régression à terme et évolution articulaire chronique. Cette mise au point décrit les deux formes de la maladie, leurs complications et les principes de leur prise en charge thérapeutique.

Periodic Fever with Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis Syndrome Is Associated with a CARD8 Variant Unable To Bind the NLRP3 Inflammasome.

Periodic fever with aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) is a relatively common autoinflammatory condition that primarily affects children. Although tendencies were reported for this syndrome, genetic variations influencing risk and disease progression are poorly understood. In this study, we performed next-generation sequencing for 82 unrelated PFAPA patients and identified a frameshift variant in the CARD8 gene (CARD8-FS). Subsequently, we compared the frequency of CARD8-FS carriers in our PFAPA cohort (13.9%) with a healthy local population group (3.2%) and found a significant association between the CARD8-FS polymorphism and risk for PFAPA syndrome (p = 0.012; odds ratio: 4.96 [95% confidence interval, 1.33-18.47]). Moreover, CARD8-FS carriers display a distinct PFAPA phenotype that is characterized by a higher prevalence of symptoms out of flares and oral aphthosis (both p = 0.02 compared with PFAPA patients without the frameshift variant). CARD8 encodes a protein component of the NLRP3 inflammasome, which plays an important role in inflammation and contributes to the pathology of various autoinflammatory diseases. We found that the CARD8-FS variant led to a truncated CARD8 protein lacking the FIIND and CARD domains. As a result, the mutant CARD8 protein lost the ability to interact with the NOD domain of NLRP3. In summary, these results identify a new CARD8 variant associated with PFAPA and further suggest that disruption of the interaction between CARD8 and NLRP3 can regulate autoinflammation in patients.

PFAPA syndrome: a review on treatment and outcome.

The syndrome of periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA syndrome) is the most common cause of periodic fever in childhood. The current pharmacological treatment includes corticosteroids, which usually are efficacious in the management of fever episodes, colchicine, for the prophylaxis of febrile episodes, and other medication for which efficacy has not been proven so far. Tonsillectomy is an option for selected patients. Usually PFAPA syndrome resolves during adolescence, but there is increasing evidence that this condition may persist into adulthood.

Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis (PFAPA) Syndrome: a Review of the Pathogenesis.

PFAPA syndrome represents the most common cause of recurrent fever in children in European populations, and it is characterized by recurrent episodes of high fever, pharyngitis, cervical adenitis, and aphthous stomatitis. Many possible causative factors have been explored so far, including infectious agents, immunologic mechanisms and genetic predisposition, but the exact etiology remains unclear. Recent findings demonstrate a dysregulation of different components of innate immunity during PFAPA flares, such as monocytes, neutrophils, complement, and pro-inflammatory cytokines, especially IL-1ß, suggesting an inflammasome-mediated innate immune system activation and supporting the hypothesis of an autoinflammatory disease. Moreover, in contrast with previous considerations, the strong familial clustering suggests a potential genetic origin rather than a sporadic disease. In addition, the presence of variants in inflammasome-related genes, mostly in NLRP3 and MEFV, suggests a possible role of inflammasome-composing genes in PFAPA pathogenesis. However, none of these variants seem to be relevant, alone, to its etiology, indicating a high genetic heterogeneity as well as an oligogenic or polygenic genetic background.

Accurate prediction of severe allergic reactions by a small set of environmental parameters (NDVI, temperature).

Severe allergic reactions of unknown etiology,necessitating a hospital visit, have an important impact in the life of affected individuals and impose a major economic burden to societies. The prediction of clinically severe allergic reactions would be of great importance, but current attempts have been limited by the lack of a well-founded applicable methodology and the wide spatiotemporal distribution of allergic reactions. The valid prediction of severe allergies (and especially those needing hospital treatment) in a region, could alert health authorities and implicated individuals to take appropriate preemptive measures. In the present report we have collecterd visits for serious allergic reactions of unknown etiology from two major hospitals in the island of Crete, for two distinct time periods (validation and test sets). We have used the Normalized Difference Vegetation Index (NDVI), a satellite-based, freely available measurement, which is an indicator of live green vegetation at a given geographic area, and a set of meteorological data to develop a model capable of describing and predicting severe allergic reaction frequency. Our analysis has retained NDVI and temperature as accurate identifiers and predictors of increased hospital severe allergic reactions visits. Our approach may contribute towards the development of satellite-based modules, for the prediction of severe allergic reactions in specific, well-defined geographical areas. It could also probably be used for the prediction of other environment related diseases and conditions.

Detection of the TNFSF members BAFF, APRIL, TWEAK and their receptors in normal kidney and renal cell carcinomas.

In advanced renal cell carcinoma (RCC), surgery combined with systemic chemotherapy and immunotherapy have had limited effectiveness. Therapeutic modalities targeting VEGF, PDGF, and c-kit using tyrosine kinase inhibitors and m-TOR using specific biologic factors are in development. Therapeutic approaches targeting TNF-alpha have shown limited efficacy, while anti-TRAIL (TNFSF10) antibodies have shown enhanced activity. The presence and potential significance of other members of the TNFSF has not been investigated. Here, we assayed the TNFSF members APRIL, BAFF, TWEAK and their receptors (BCMA, TACI, BAFFR, Fn14) in 86 conventional type clear cell RCC, using immunohistochemistry and correlated our findings with histological data and, in a limited series, follow-up of patients. We observed a differential expression of these TNFSF ligands and receptors in cancerous and non-cancerous structures. BAFF was found in all RCC; APRIL expression is associated with an aggressive phenotype, correlating negatively with patients' disease-free survival, while TWEAK and its receptor Fn14 are heterogeneously expressed, correlating negatively with the grade and survival of RCC patients. This is the first study, presenting together the TNFSF members APRIL, BAFF, TWEAK and their receptors in different areas of normal renal tissue and RCC, suggesting a potential role of these TNFSF members in renal tumor biology.

Novel oligomeric proanthocyanidin derivatives interact with membrane androgen sites and induce regression of hormone-independent prostate cancer.

Prostate cancer is the most common malignancy among men in Western societies, and current therapeutic approaches are evolving to manage growth, recurrence, and mortality neoplasia. Membrane androgen receptors (mARs) have been characterized in human prostate cancer, being preferentially expressed in tumor rather than benign gland areas. Furthermore, mAR agonists (protein-conjugated testosterone) decrease in vitro prostate cancer cell growth and induce apoptosis, whereas in vivo they regress growth of tumor xenografts alone or in combination with taxane drugs. In this respect, targeting mARs might be a novel therapeutic approach in prostate cancer. In our search for new small-molecule ligands of mAR, we report that flavanol dimers B1-B4 (oligomeric procyanidins) decrease in vitro growth of the androgen-sensitive (LnCaP) and androgen-resistant (DU145) human prostate cancer cell lines in the following order: B3 = B4 > B2 ≫ B1 (LnCaP) and B2 ≫ B3 = B4 ≫ B1 (DU145). Some of these analogs were previously shown to trigger signaling cascades similar to testosterone-bovine serum albumin (BSA) conjugate. Galloylation does not confer an additional advantage; however, oleylation increases the dimers' antiproliferative potency by a factor of 100. In addition, we report that B2, oleylated or not, displaces testosterone from mARs with an IC(50) value at the nanomolar range and induces DU145 tumor xenograft regression by 50% (testosterone-BSA 40%). In this respect, oleylated B2 is a potent small-molecule agonist of mAR and could be a novel therapeutic agent for advanced prostate cancer, especially when taking into account the absence of androgenic actions and (liver) toxicity.