Pathogenesis of familial periodic fever syndromes or hereditary autoinflammatory syndromes

Pyroptosis-Mediated Periodontal Disease

Pyroptosis is a caspase-dependent process relevant to the understanding of beneficial host responses and medical conditions for which inflammation is central to the pathophysiology of the disease. Pyroptosis has been recently suggested as one of the pathways of exacerbated inflammation of periodontal tissues. Hence, this focused review aims to discuss pyroptosis as a pathological mechanism in the cause of periodontitis. The included articles presented similarities regarding methods, type of cells applied, and cell stimulation, as the outcomes also point to the same direction considering the cellular events. The collected data indicate that virulence factors present in the diseased periodontal tissues initiate the inflammasome route of tissue destruction with caspase activation, cleavage of gasdermin D, and secretion of interleukins IL-1β and IL-18. Consequently, removing periopathogens’ virulence factors that trigger pyroptosis is a potential strategy to combat periodontal disease and regain tissue homeostasis.

Autosomal dominant familial periodic fever patient with a missense variant c.215G>A (p.Cys72Tyr) in TNFRSF1A gene presenting as neutrophilia

Familial periodic fever (FPF) is an uncommonly diagnosed autosomal dominant disorder caused by a genetic alteration in the TNFRSF1A gene. These patients usually present with fever which is usually under-investigated and under-diagnosed. In untreated cases, amyloidosis is a frequent complication. We present a 24 years male who had a history of fever from childhood, however, remained undiagnosed short of genetic testing. He has recurrent episodes of fever. During the episodes of fever, he was found to have leukocytosis (total leukocyte count- 25.7 x10^9/L) and neutrophilia (absolute neutrophil count- 22.7 x10^9/L) both of which came back to normal limits as the fever subsided. On further evaluation for neutrophilia, the exclusion of common causes of neutrophilia was done. Next-generation sequencing detected a missense variant in TNFRSF1A: c.215G > A (p.Cys72Tyr) which was confirmed by Sanger sequencing. This variant has been described in the literature in anecdotal cases of FPF. This is a first case report from the Indian subcontinent reporting TNFRSF1A: c.215G > A (p.Cys72Tyr) variant in a patient of FPF. Short of genetic testing, the fever would remain a diagnostic dilemma in this patient. This report highlights the importance of targeted resequencing in clinching diagnosis in such patients.

Interleukin (IL)-1 family cytokines could differentiate primary immune thrombocytopenia from systemic lupus erythematosus-associated thrombocytopenia

Background

Primary immune thrombocytopenia (ITP) is an autoimmune-mediated disorder characterized by a decreased platelet count. Systemic lupus erythematosus (SLE) is also an autoimmune disease in which thrombocytopenia is a common hematologic manifestation. Interleukin (IL)-1 family cytokines are major proinflammatory and immunoregulatory mediators. This study aimed to investigate the role of IL-1 cytokines in patients with ITP and SLE and the potential pathophysiologic mechanism to differentiate SLE-associated thrombocytopenia (SLE-TP) from ITP.

Methods

Multiplex cytokine assay and real-time polymerase chain reaction (RT-PCR) were used to measure IL-1 cytokines in 17 newly diagnosed ITP patients, 17 SLE-TP patients, 19 SLE patients without thrombocytopenia (SLE-NTP), and 10 healthy controls.

Results

The serum levels of IL-1β, IL-18, IL-36α, IL-36β, IL-36γ, and IL-33 were decreased significantly in ITP patients compared with SLE-TP patients, SLE-NTP patients, and healthy controls (P<0.05). While there was no significant difference in the serum level of IL-37 between ITP and SLE-TP patients, there was a positive correlation between the platelet count and IL-37 level in ITP patients. Our data suggested that serum IL-1β, IL-18, IL-36α, IL-36β, IL-36γ, IL-33, and IL-37 could be considered biomarkers in the diagnosis of ITP.

Conclusions

Serum IL-1β, IL-18, IL-36α, IL-36β, IL-36γ, and IL-33 could be considered biomarkers to differentiate SLE-TP from ITP patients.

Ancient friends, revisited: Systematic review and case report of pyoderma gangrenosum-associated autoinflammatory syndromes

In the last decade, new scientific findings significantly improved our understanding of the molecular pathogenesis of autoinflammation and have resulted in the identification and definition of several pyoderma gangrenosum-associated autoinflammatory syndromes (PGAAIS) as new and distinct clinical entities. These different clinical entities include PAPA (pyogenic arthritis, pyoderma gangrenosum and acne conglobata), PASH (pyoderma gangrenosum, acne and suppurative hidradenitis), PAPASH (pyoderma gangrenosum, acne, suppurative hidradenitis and pyogenic arthritis), PsAPASH (pyoderma gangrenosum, acne, suppurative hidradenitis and psoriatic arthritis), PASS (pyoderma gangrenosum, acne conglobata, suppurative hidradenitis, and axial spondyloarthritis) and PAC (pyoderma gangrenosum, acne and ulcerative colitis), which can be distinguished by their clinical presentation and the presence or absence of mutations in several genes, such as the genes encoding proline-serine-threonine phosphatase-interacting protein 1 (PSTPIP1), nicastrin (NCSTN), Mediterranean fever (MEFV) and nucleotide-binding oligomerization domain-containing protein (NOD). In this systematic review, we summarize the present knowledge of this rapidly developing hot topic and provide a guide to enable the easy diagnosis of these syndromes in everyday clinical practice. Moreover, we report a rare case of PASS syndrome demonstrating successful treatment with adalimumab and another case of a previously unreported combination of symptoms, including psoriatic arthritis, pyoderma gangrenosum, suppurative hidradenitis and Crohn’s disease (newly coined PsAPSC), as examples. Because of the identification of similar genetic and pathogenic mechanisms of PGAAIS, we think the wide variety of seemingly different syndromes may represent distinct phenotypes of one disease.

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New scientific findings improved the understanding of the molecular pathogenesis of autoinflammation.

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There is a similar genetic background and clinical findings of PGAAIS.

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Because of the similar genetic and pathogenic mechanisms of PGAAIS may represent distinct phenotypes of one disease.

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We present a 4-sep guide to enable the easy diagnosis of theses disease in clinical practice.

Investigation of anti-inflammatory potential of 5-(3,5-di-tert-butyl-4-hydroxybenzylidene)-2-thioxodihydropyrimidine-4,6(1H,5H)-dione compound

The aim of this study was to synthesise the novel di-tert-butylphenol compound, 5-(3,5-di-tert-butyl-4-hydroxybenzylidene)-2-thioxo-dihydropyrimidine-4,6(1H, 5H)-dione (LQFM218), and evaluate the potential anti-nociceptive and anti-inflammatory activities in acute (mice) models in vivo. The compound was tested on acute models of pain such as acetic acid-induced abdominal writhing, formalin-induced nociception and carrageenan-induced mechanical hyperalgesia. The anti-inflammatory activity was observed in paw oedema, carrageenan-induced pleurisy tests and inflammatory mediator quantification. Key findings: oral treatment with the LQFM218 (50, 100 or 200 mg/kg) reduced abdominal writhing (18.8%, 31.6% and 48.3%). The dose intermediate (100 mg/kg) reduced the nociception in the second phase of the formalin test (61.4%), and also showed anti-hyperalgic activity in carrageenan-induced mechanical hyperalgesia (until 42.3%). In acute inflammation models, the treatment of mice LQFM218 (100 mg/kg) reduced the paw oedema all the time (33.8%, 42.6%, 37.4% and 36%) and in pleurisy test reduced: polymorphonuclear cell migration (35.4%), myeloperoxidase activity (52.2%) and the levels of inflammatory mediators such as PGE₂ (23.0%), TNF-α (67.6%) and IL-1β (53.4%). The present study showed that LQFM218 effectively reduced the nociception and inflammation in different models, and its mechanism might be related to the reduction of PGE₂ and pro-inflammatory cytokines. These findings show LQFM218 as a potential anti-inflammatory drug.

Autoinflammatory Diseases in Childhood

Autoinflammatory diseases are characterized by recurrent fevers and clinical findings of impaired natural immunity and can involve various organ systems. The concept of autoinflammatory disease emerged after the definition of familial Mediterranean fever and tumor necrosis factor receptor-associated periodic syndrome. This new disease group was considered to differ from the standard concept of autoimmune diseases, which is relatively better known in terms of basic features, such as defects in innate immunity and the absence of antibodies. A better understanding has been achieved regarding the genetic and pathogenetic mechanisms of this relatively new disease group over the past 20 years since they were first diagnosed, which have led to some changes in the concept of autoinflammatory diseases. The recent definition classifies autoinflammatory disease to be a wide range of diseases with different clinical features, mainly accompanied by changes in innate immune and rarely in humoral immunity. The spectrum of autoinflammatory diseases is rapidly expanding owing to recent developments in molecular sciences and genetics. This review article discusses the clinical features, classification criteria, treatment options, and long-term prognosis of periodic fever, aphthous stomatitis, pharyngitis, adenitis syndrome, and other common autoinflammatory diseases in the light of current literature.

GSDMB promotes non-canonical pyroptosis by enhancing caspase-4 activity

Gasdermin B (GSDMB) has been reported to be associated with immune diseases in humans, but the detailed molecular mechanisms remain unsolved. The N-terminus of GSDMB by itself, unlike other gasdermin family proteins, does not induce cell death. Here, we show that GSDMB is highly expressed in the leukocytes of septic shock patients, which is associated with increased release of the gasdermin D (GSDMD) N-terminus. GSDMB expression and the accumulation of the N-terminal fragment of GSDMD are induced by the activation of the non-canonical pyroptosis pathway in a human monocyte cell line. The downregulation of GSDMB alleviates the cleavage of GSDMD and cell death. Consistently, the overexpression of GSDMB promotes GSDMD cleavage, accompanied by increased LDH release. We further found that GSDMB promotes caspase-4 activity, which is required for the cleavage of GSDMD in non-canonical pyroptosis, by directly binding to the CARD domain of caspase-4. Our study reveals a GSDMB-mediated novel regulatory mechanism for non-canonical pyroptosis and suggests a potential new strategy for the treatment of inflammatory diseases.

Role of pyroptosis in liver diseases

Pyroptosis is known as a novel form of pro-inflammatory cell death program, which is exceptional from other types of cell death programs. Particularly, pyroptosis is characterized by Gasdermin family-mediated pore formation and subsequently cellular lysis, also release of several pro-inflammatory intracellular cytokines. In terms of mechanism, there are two signaling pathways involved in pyroptosis, including caspase-1, and caspase-4/5/11 mediated pathways. However, pyroptosis plays important roles in immune defense mechanisms. Recent studies have demonstrated that pyroptosis plays significant roles in the development of liver diseases. In our review, we have focused on the role of pyroptosis based on the molecular and pathophysiological mechanisms in the development of liver diseases. We have also highlighted targeting of pyroptosis for the therapeutic implications in liver diseases in the near future.

Caspase-1-Dependent Pyroptosis of Peripheral Blood Mononuclear Cells Is Associated with the Severity and Mortality of Septic Patients

Purpose

Pyroptosis has been known to play a vital role in the inflammation process which was induced by infection, injury, or inflammatory disease. The present study was aimed at evaluating the percentage of peripheral blood mononuclear cell (PBMC) pyroptosis in septic patients and assessing the correlation of PBMC pyroptosis with the severity and the mortality of septic patients.

Methods

128 trauma-induced patients with sepsis were enrolled in this prospective cohort study. Blood samples were collected, and PBMC pyroptosis was measured by flow cytometry within 24 hours after sepsis was diagnosed.

Results

Percentage of PBMC pyroptosis was positively correlated with the acute physiology and chronic health evaluation (APACHE) II score and sequential organ failure assessment (SOFA) score (all P < 0.01). The area under the curve (AUC) for the percentage of PBMC pyroptosis on a receiver operating characteristic curve was 0.79 (95% confidence interval (CI), 0.68–0.90). A Cox proportional hazard model identified an association between an increased percentage of PBMC pyroptosis (>14.17%) and increased risk of the 28-day mortality (hazard ratio = 1.234, 95% CI, 1.014–1.502).

Conclusion

The percentage of PBMC pyroptosis increases in septic patients, and the increased percentage of PBMC pyroptosis is associated with the severity of sepsis and the 28-day mortality of patients with sepsis.

Uric acid increases IL-1β secretion and Caspase-1 activation in PBMCs of Behçet's disease patients: The in vitro immunomodulatory effect of xanthine oxidase inhibitor Allopurinol

Behçet's disease (BD) is a multisystem disease, which shares some features with other diseases belonging to the autoinflammatory disorders panel. Recent studies have postulated that IL-1β/Caspase-1 may play a cardinal role in autoinflammatory diseases. In this study, we aimed to (i) elucidate the mechanism underlying the involvement of xanthine oxidase (XO) and Uric Acid (UA) in BD (ii) study the direct effects of UA and XO inhibitor "Allopurinol" on nitric oxide (NO) and caspase-1-mediated IL-1β release in peripheral blood mononuclear cells (PBMCs) of BD patients. In this context, plasma of BD patients and healthy controls (HC) were used to measure XO activity, UA, advanced oxidized proteins products (AOPP) and NO levels. In Addition, PBMCs of BD patients and HC were treated or not with either UA or Allopurinol. Then we quantified NO and IL-1β levels, and Caspase-1 Activity in the supernatants and lysates of PBMCs, respectively. We showed that plasma levels of XO activity, UA, AOPP and NO are significantly increased in BD patients compared to those of HC. Interestingly, a significant positive correlation between XO and UA was observed in BD patients. Additionally, while UA has markedly increased NO, IL-1β, and Caspase-1 activity levels in PBMCs of BD patients, Allopurinol has exerted an immunomodulatory effect resulting in reduced NO, IL-1β and Caspase-1 levels in PBMCs of BD patients particularly during the active stages. Collectively, our results indicate a potential clinical use of XO as a tool for assessing BD activity, and suggest that the in-vitro immunomodulatory effect of Allopurinol may have a promising therapeutic value in BD management.

The interplay of autophagy and non-apoptotic cell death pathways

Autophagy, the process of macromolecular degradation through the lysosome, has been extensively studied for the past decade or two. Autophagy can regulate cell death, especially apoptosis, through selective degradation of both positive and negative apoptosis regulators. However, multiple other programmed cell death pathways exist. As knowledge of these other types of cell death expand, it has been suggested that they also interact with autophagy. In this review, we discuss the molecular mechanisms that comprise three non-apoptotic forms of cell death (necroptosis, pyroptosis and ferroptosis) focusing on how the autophagy machinery regulates these different cell death mechanisms through (i) its degradative functions, i.e., true autophagy, and (ii) other non-degradative functions of the autophagy machinery such as serving as a signaling scaffold or by participating in other autophagy-independent cellular processes.

Familial mediterranean fever: clinical case

Background. Familial Mediterranean fever (FMF) is the brightest exponent of autoinflammatory diseases. FMF usually occurs to people of Mediterranean origin (Jews, Armenians, Azerbaijanis, Arabs, Kurds, Greeks, Turks and Italians). This is a hereditary disease with the autosomal recessive inheritance. Includes history of research, epidemiology FMF, variants of the disease course, methods of treatment. Clinical case description. A 61-year-old woman arrived complaining of weakness, fever, joint pain. First sign of disease showed at 20-years-old. When she came in: WBC 20.1–109/l, HGB 6.7 g/ml, ESR 60 mm/h, CRP 100 mg/l, CRP 202 μmol/L, UREA 19.7 mmol/L. Quantity of protein in one liter of urine 0.160 g. Ultrasonic signs of pyelectasis in both kidneys. The diagnosis was made on the basis of characteristic attacks of fever, polyarthritis, thoracalgia of Armenian nationality patient. The diagnosis was confirmed by the detection of amyloidosis and genetic data. Conclusion. Knowledge of the FMF clinical profile is important for differential diagnosis with many acute conditions, e.g. acute abdomen, myocardial infarction, pneumothorax, rheumatic diseases. It is important to remember that untimely diagnosis and improper treatment lead to the development of AA-amyloidosis (30–40%) with the outcome of renal failure.

The long and winding road in pharmaceutical development of canakinumab from rare genetic autoinflammatory syndromes to myocardial infarction and cancer

Interleukin-1beta (IL-1β) is an ancient and evolutionary conserved cytokine, which orchestrates innate immune responses triggered by infections in vertebrates. While temporally limited induction of IL-1β protects the organism against traumatic or infectious insults, its chronic production in unabated inflammation causes or enhances clinical manifestations of disease in almost all organ systems. Therefore, pharmacological targeting of IL-1β in a variety of clinical inflammatory conditions may provide symptomatic relief or profound disease modification. The discovery of proteolytic processing of the inactive pro-IL-1β to mature, active and secreted IL-1β by the inflammasome/caspase 1 complex entailed a number of drug discovery programs aiming towards low molecular weight inhibitors across the Pharma industry. Approved and marketed IL-1 pathway drugs today, however, are protein-based injectable drugs ("biologics") targeting either IL-1β, or the IL-1 receptor. Canakinumab is a human monoclonal antibody that binds human IL-1β with high affinity and neutralizes its biological activity. This review describes the unique preclinical and clinical development journey of canakinumab starting from a rare genetic autoinflammatory disease and a systemic juvenile form of arthritis to further rare monogenetic periodic fever syndromes, and leading to non-orphan diseases, such as gout, myocardial infarction, and lung cancer.

Caspase-1-dependent pyroptosis of peripheral blood mononuclear cells predicts the development of sepsis in severe trauma patients: A prospective observational study

Pyroptosis plays a pivotal role in sepsis and septic shock in animal studies. However, its clinical significance in pathological conditions has not been well elucidated. This study aimed to evaluate the correlation between the percentage of pyroptotic peripheral blood mononuclear cells (PBMCs) and the clinical index and to investigate the relationship between PBMCs pyroptosis and the development of sepsis in trauma patients.This prospective study was conducted from October 2016 to May 2017 in a comprehensive trauma center. Sixty trauma patients and 10 healthy controls were enrolled. Peripheral blood samples were collected from the patients within 24 hours after injury. The percentages of pyroptotic and apoptotic PBMCs were measured using flow cytometry, and plasma levels of cytokines were evaluated using flow cytometric analysis with a human inflammation 13-plex panel.Trauma patients who developed sepsis had higher percentages of pyroptotic and apoptotic PBMCs at admission. Patients who developed sepsis (n = 33) had higher interleukin (IL)-6, IL-18, and monocyte chemotactic protein-1 (MCP-1) concentrations at admission than patients (n = 27) who did not develop sepsis. The percentage of PBMCs pyroptosis was significantly correlated with injury severity score (ISS), acute physiology and chronic health evaluation (APACHE) II score, IL-10, IL-18, and MCP-1 levels in trauma patients. PBMCs pyroptosis is a better biomarker in predicting the development of sepsis after trauma.This study indicates that the percentage of pyroptotic PBMCs increases during the early phase of trauma and that this increase is significantly correlated with the severity and state of inflammation in trauma patients. PBMCs pyroptosis is a potential marker for predicting the development of sepsis after trauma.

Porphyromonas gingivalis-Derived Lipopolysaccharide Combines Hypoxia to Induce Caspase-1 Activation in Periodontitis

Periodontitis is defined as inflammation affecting the supporting tissue of teeth. Periodontal pathogens initiate the disease and induce inflammatory host response. Hypoxia may accelerate the process by producing pro-inflammatory factors. The aim of this study is to investigate the effect of Porphyromonas gingivalis (P. gingivalis) lipopolysaccharides (LPS) and Escherichia coli (E. coli) LPS in inducing caspase-1 activation in normoxic or hypoxic phases. The results showed that healthy gingiva was in a normoxic phase (HIF-1α negative). However, hypoxia appeared in periodontitis, in which NLRP3, cleaved-caspase-1, interleukin 1 beta (IL-1β) and caspase-1-induced cell death was enhanced in periodontitis specimens. The in vitro experiment showed that P. gingivalis LPS slightly decreased the level of NLRP3 and IL-1β in gingival fibroblasts under normoxia. Surprisingly, hypoxia reversed the effects of P. gingivalis LPS, highly promoted caspase-1 activation and IL-1β maturation. E. coli LPS, a kind of pathogen-associated molecular pattern (PAMP) was chosen to simulate the effect of Gram-negative microbiota. Different from P. gingivalis LPS, E. coli LPS enhanced IL-1β maturation both in normoxia and hypoxia. Moreover, E. coli LPS turned normoxia into hypoxia phase in experimental periodontitis model, which may subsequently propel the inflammatory effect of P. gingivalis LPS. It was concluded that E. coli LPS induced a hypoxic phase, which is a combing pathological factor of P. gingivalis LPS in caspase-1 activating and IL-1β maturation in periodontal inflammation.

Diabetes and Sepsis: Risk, Recurrence, and Ruination

Sepsis develops when an infection surpasses local tissue containment. A series of dysregulated physiological responses are generated, leading to organ dysfunction and a 10% mortality risk. When patients with sepsis demonstrate elevated serum lactates and require vasopressor therapy to maintain adequate blood pressure in the absence of hypovolemia, they are in septic shock with an in-hospital mortality rate >40%. With improvements in intensive care treatment strategies, overall sepsis mortality has diminished to ~20% at 30 days; however, mortality continues to steadily climb after recovery from the acute event. Traditionally, it was thought that the complex interplay between inflammatory and anti-inflammatory responses led to sepsis-induced organ dysfunction and mortality. However, a closer examination of those who die long after sepsis subsides reveals that many initial survivors succumb to recurrent, nosocomial, and secondary infections. The comorbidly challenged, physiologically frail diabetic individuals suffer the highest infection rates. Recent reports suggest that even after clinical "recovery" from sepsis, persistent alterations in innate and adaptive immune responses exists resulting in chronic inflammation, immune suppression, and bacterial persistence. As sepsis-associated immune defects are associated with increased mortality long-term, a potential exists for immune modulatory therapy to improve patient outcomes. We propose that diabetes causes a functional immune deficiency that directly reduces immune cell function. As a result, patients display diminished bactericidal clearance, increased infectious complications, and protracted sepsis mortality. Considering the substantial expansion of the elderly and obese population, global adoption of a Western diet and lifestyle, and multidrug resistant bacterial emergence and persistence, diabetic mortality from sepsis is predicted to rise dramatically over the next two decades. A better understanding of the underlying diabetic-induced immune cell defects that persist following sepsis are crucial to identify potential therapeutic targets to bolster innate and adaptive immune function, prevent infectious complications, and provide more durable diabetic survival.

Skin symptoms as diagnostic clue for autoinflammatory diseases

Autoinflammatory disorders are immune-mediated diseases with increased production of inflammatory cytokines and absence of detectable autoantibodies. They course with recurrent episodes of systemic inflammation and fever is the most common symptom. Cutaneous manifestations are prevalent and important to diagnosis and early treatment of the syndromes. The purpose of this review is to emphasize to dermatologists the skin symptoms present in these syndromes in order to provide their early diagnosis.

Amyloidosis: A cancer-derived paraproteinemia and kidney involvement

Amyloidosis is the general term describing the extracellular tissue deposition of fibrils composed of low molecular weight subunits of a variety of proteins. There are multiple different human protein precursors of amyloid fibrils. Amyloid deposits are stained using Congo Red and show typical apple-green birefringence in polarized microscopy. Nowadays, a novel technique LMD/MS technique or laser microdissection combined with mass spectrometry help to diagnose amyloidosis. Amyloidosis of the kidney is typically classified as being either one of two types: AL or AA. Less common is the hereditary amyloidosis. Clinical manifestations are usually determined by the type of precursor protein, the tissue distribution, and the amount of amyloid deposition. Renal manifestation is usually present as asymptomatic proteinuria or clinically apparent nephrotic syndrome. In some patients clinical presentation include impaired kidney function with no or mild proteinuria. Patients with renal amyloidosis who progress to end-stage renal disease (ESRD) can be treated with either dialysis or renal transplantation. Diagnosis of amyloidosis is prerequisite to consider treatment options to avoid unnecessary chemotherapy. Treatment of amyloidosis is aimed at decreasing the precursors of fibrillary proteins and/or decrease in synthesis/deposition of amyloid fibrils. It depends upon the type of amyloidosis and cause of excess fibril production.

Lesson of the month 1: Autoinflammatory syndromes - an unusual cause of pyrexia of unknown origin

Autoinflammatory diseases are disorders of innate immunity and are characterised by recurring and unprovoked episodes of inflammation. We present a case of episodic pyrexia, associated with a significant inflammatory response, in a young man in whom the cause had remained unexplained since infancy. He was eventually diagnosed with hyperimmunoglobulinaemia D syndrome (HIDS); one of the autoinflammatory syndromes.

Systemic and organ involvement in monogenic autoinflammatory disorders: a global review filtered through internists' lens

Monogenic autoinflammatory disorders (AIDs) are rare diseases driven by cytokine-mediated extraordinary sterile inflammation that results from the activation of innate immune pathways. The clinical hallmark of these diseases is the recurrence of stereotyped episodes of systemic- and organ-specific inflammation; the most common systems involved being the skin, musculoskeletal system, gastrointestinal tract, and central nervous system. The autoinflammatory disorders may have a profound impact on the quality of life of the affected patients, and a delayed diagnosis may lead to severe complications, the most dreadful of which is AA-Amyloidosis. This review gives an overview on the four main AIDs, namely familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, cryopyrinopathies, and mevalonate kinase deficiency, focusing on their clinical phenotype in adults and differential diagnosis, suggesting a diagnostic algorithm, and reviewing the available treatments.

Genetically defined autoinflammatory diseases

Autoinflammatory diseases are hyperinflammatory, immune dysregulatory conditions that typically present in early childhood with fever and rashes and disease-specific patterns of organ inflammation. This review provides a historic background of autoinflammatory disease research, an overview of the currently genetically defined autoinflammatory diseases, and insights into treatment strategies derived from understanding of the disease pathogenesis. The integrative assessment of autoinflammatory conditions led to the identification of innate pro-inflammatory cytokine 'amplification loops' as the cause of the systemic and organ-specific disease manifestations, which initially centered around increased IL-1 production and signaling. More recently, additional innate pro-inflammatory cytokine amplification loops resulting in increased Type I IFN, IL-17, IL-18, or IL-36 signaling or production have led to the successful use of targeted therapies in some of these conditions. Clinical findings such as fever patterns, type of skin lesions, genetic mutation testing, and the prevalent cytokine abnormalities can be used to group autoinflammatory diseases.

Preclinical characterization and clinical development of ILARIS(®) (canakinumab) for the treatment of autoinflammatory diseases

Interleukin-1beta (IL-1β) is a pro-inflammatory cytokine which is part of the first line innate response in vertebrates and is induced in injury, infection, and immunity. While temporally limited induction of IL-1β is believed to protect the organisms against traumatic or infectious insults, its aberrant expression in chronic inflammation is detrimental. Therefore, pharmacological neutralization of IL-1β in chronic inflammatory diseases is a meaningful strategy to treat inflammation and to alleviate respective clinical symptoms in man. Canakinumab is a high-affinity human monoclonal antibody designed to target human IL-1β in inflammatory diseases. Indeed, canakinumab has shown excellent efficacy in rare genetic autoinflammatory diseases or pathological conditions associated with aberrant production of IL-1β. This review focuses on the molecular and clinical mode of action and pharmaceutical development of canakinumab in (auto)inflammatory diseases.

New Insights Into Tissue Macrophages: From Their Origin to the Development of Memory

Macrophages are the main effector cells of innate immunity and are involved in inflammatory and anti-infective processes. They also have an essential role in maintaining tissue homeostasis, supporting tissue development, and repairing tissue damage. Until few years ago, it was believed that tissue macrophages derived from circulating blood monocytes, which terminally differentiated in the tissue and unable to proliferate. Recent evidence in the biology of tissue macrophages has uncovered a series of immune and ontogenic features that had been neglected for long, despite old observations. These include origin, heterogeneity, proliferative potential (or self-renewal), polarization, and memory. In recent years, the number of publications on tissue resident macrophages has grown rapidly, highlighting the renewed interest of the immunologists for these key players of innate immunity. This mini-review aims to summarizing the new current knowledge in macrophage immunobiology, in order to offer a clear and immediate overview of the field.

Induction of interleukin-1 beta (IL-1β) is a critical component of lung inflammation during influenza A (H1N1) virus infection

Cytokine storm during influenza virus infection is recognized as a predictor of morbidity and mortality. To verify the cellular effects of influenza-induced cytokines in primary normal lung cells, human pulmonary microvascular endothelial cells (HMVECs) and lung fibroblast cells (MRC-5 cells) were infected with influenza virus H1N1. H1N1 infection induced the transcription of various genes encoding cytokines and chemokines such as interleukin-1 beta (IL-1β), IL-6, IL-8, IL-12A, tumor necrosis factor alpha (TNF-α), and chemokine (C-C motif) ligand 5 (CCL5) in both endothelial cells and lung fibroblasts. Among them, IL-1β induction by influenza infection increased the inflammation of lung cells; conversely, blockade of IL-1β signals with an IL-1β receptor antagonist or a neutralizing antibody alleviated influenza-driven inflammation. In conclusion, these data suggest that secreted IL-1β by the endothelial cells contributes to influenza-induced inflammation, and blockade of IL-1β signals is a potential treatment or therapeutic target for influenza-induced inflammation.

Familial Mediterranean Fever

Familial Mediterranean Fever is an autosomal recessive inherited disease with a course of autoinflammation, which is characterized by the episodes of fever and serositis. It affects the populations from Mediterranean basin. Genetic mutation of the disease is on MEFV gene located on short arm of Chromosome 16. The disease is diagnosed based on clinical evaluation. Amyloidosis is the most important complication. The only agent that decreases the development of amyloidosis and the frequency and severity of the episodes is colchicine, which has been used for about 40 years. In this review, we aimed to discuss especially the most recent advances about Familial Mediterranean Fever which is commonly seen in our population.

Programmed cell death and its role in inflammation

Cell death plays an important role in the regulation of inflammation and may be the result of inflammation. The maintenance of tissue homeostasis necessitates both the recognition and removal of invading microbial pathogens as well as the clearance of dying cells. In the past few decades, emerging knowledge on cell death and inflammation has enriched our molecular understanding of the signaling pathways that mediate various programs of cell death and multiple types of inflammatory responses. This review provides an overview of the major types of cell death related to inflammation. Modification of cell death pathways is likely to be a logical therapeutic target for inflammatory diseases.

An expanding role for interleukin-1 blockade from gout to cancer

There is an expanding role for interleukin (IL)-1 in diseases from gout to cancer. More than any other cytokine family, the IL-1 family is closely linked to innate inflammatory and immune responses. This linkage is because the cytoplasmic segment of all members of the IL-1 family of receptors contains a domain, which is highly homologous to the cytoplasmic domains of all toll-like receptors (TLRs). This domain, termed "toll IL-1 receptor (TIR) domain," signals as does the IL-1 receptors; therefore, inflammation due to the TLR and the IL-1 families is nearly the same. Fundamental responses such as the induction of cyclo-oxygenase type 2, increased surface expression of cellular adhesion molecules and increased gene expression of a broad number of inflammatory molecules characterizes IL-1 signal transduction as it does for TLR agonists. IL-1β is the most studied member of the IL-1 family because of its role in mediating autoinflammatory disease. However, a role for IL-1α in disease is being validated because of the availability of a neutralizing monoclonal antibody to human IL-1α. There are presently three approved therapies for blocking IL-1 activity. Anakinra is a recombinant form of the naturally occurring IL-1 receptor antagonist, which binds to the IL-1 receptor and prevents the binding of IL-1β as well as IL-1α. Rilonacept is a soluble decoy receptor that neutralizes primarily IL-1β but also IL-1α. Canakinumab is a human monoclonal antibody that neutralizes only IL-1β. Thus, a causal or significant contributing role can be established for IL-1β and IL-1α in human disease.

Inborn errors of metabolism underlying primary immunodeficiencies

A number of inborn errors of metabolism (IEM) have been shown to result in predominantly immunologic phenotypes, manifesting in part as inborn errors of immunity. These phenotypes are mostly caused by defects that affect the (i) quality or quantity of essential structural building blocks (e.g., nucleic acids, and amino acids), (ii) cellular energy economy (e.g., glucose metabolism), (iii) post-translational protein modification (e.g., glycosylation) or (iv) mitochondrial function. Presenting as multisystemic defects, they also affect innate or adaptive immunity, or both, and display various types of immune dysregulation. Specific and potentially curative therapies are available for some of these diseases, whereas targeted treatments capable of inducing clinical remission are available for others. We will herein review the pathogenesis, diagnosis, and treatment of primary immunodeficiencies (PIDs) due to underlying metabolic disorders.

Treating inflammation by blocking interleukin-1 in humans

IL-1 is a master cytokine of local and systemic inflammation. With the availability of specific IL-1 targeting therapies, a broadening list of diseases has revealed the pathologic role of IL-1-mediated inflammation. Although IL-1, either IL-1α or IL-1β, was administered to patients in order to improve bone marrow function or increase host immune responses to cancer, these patients experienced unacceptable toxicity with fever, anorexia, myalgias, arthralgias, fatigue, gastrointestinal upset and sleep disturbances; frank hypotension occurred. Thus it was not unexpected that specific pharmacological blockade of IL-1 activity in inflammatory diseases would be beneficial. Monotherapy blocking IL-1 activity in a broad spectrum of inflammatory syndromes results in a rapid and sustained reduction in disease severity. In common conditions such as heart failure and gout arthritis, IL-1 blockade can be effective therapy. Three IL-1blockers have been approved: the IL-1 receptor antagonist, anakinra, blocks the IL-1 receptor and therefore reduces the activity of IL-1α and IL-1β. A soluble decoy receptor, rilonacept, and a neutralizing monoclonal anti-interleukin-1β antibody, canakinumab, are also approved. A monoclonal antibody directed against the IL-1 receptor and a neutralizing anti-IL-1α are in clinical trials. By specifically blocking IL-1, we have learned a great deal about the role of this cytokine in inflammation but equally important, reducing IL-1 activity has lifted the burden of disease for many patients.

Detailed mechanistic analysis of gevokizumab, an allosteric anti-IL-1β antibody with differential receptor-modulating properties

Interleukin-1β (IL-1β) is a proinflammatory cytokine that is implicated in many autoinflammatory disorders, but is also important in defense against pathogens. Thus, there is a need to safely and effectively modulate IL-1β activity to reduce pathology while maintaining function. Gevokizumab is a potent anti-IL-1β antibody being developed as a treatment for diseases in which IL-1β has been associated with pathogenesis. Previous data indicated that gevokizumab negatively modulates IL-1β signaling through an allosteric mechanism. Because IL-1β signaling is a complex, dynamic process involving multiple components, it is important to understand the kinetics of IL-1β signaling and the impact of gevokizumab on this process. In the present study, we measured the impact of gevokizumab on the IL-1β system using Schild analysis and surface plasmon resonance studies, both of which demonstrated that gevokizumab decreases the binding affinity of IL-1β for the IL-1 receptor type I (IL-1RI) signaling receptor, but not the IL-1 counter-regulatory decoy receptor (IL-1 receptor type II). Gevokizumab inhibits both the binding of IL-1β to IL-1RI and the subsequent recruitment of IL-1 accessory protein primarily by reducing the association rates of these interactions. Based on this information and recently published structural data, we propose that gevokizumab decreases the association rate for binding of IL-1β to its receptor by altering the electrostatic surface potential of IL-1β, thus reducing the contribution of electrostatic steering to the rapid association rate. These data indicate, therefore, that gevokizumab is a unique inhibitor of IL-1β signaling that may offer an alternative to current therapies for IL-1β-associated autoinflammatory diseases.

Intermittent neutropenia as an early feature of mild mevalonate kinase deficiency

A 15-month-old boy, born to Iranian consanguineous parents presented with intermittent neutropenia interspersed with episodes of fever and leukocytosis since early infancy. No ELA2 mutations were found and the bone marrow study was normal. At age 4 years he progressed to more typical attacks of periodic attacks of fever, abdominal pain, oral aphthous ulcers, cutaneous rash and leukocytosis. The clinical and laboratory features were compatible with the mild form of mevalonate kinase deficiency, usually named "Hyper-IgD and periodic fever syndrome" (HIDS). Genomic sequencing of the mevalonate kinase (MVK) gene revealed homozygous missense mutation (p.Val377Ile). On demand dexamethasone resulted in a rapid amelioration of febrile episodes. The presentation of intermittent neutropenia has not been reported in HIDS and deserves more attention in large patient cohorts.

Genetic support for the role of the NLRP3 inflammasome in psoriasis susceptibility

NACHT leucine-rich repeat- and PYD-containing (NLRP)3 protein controls the inflammasome by regulating caspase-1 activity and interleukin (IL)-1β processing. The contribution of IL-1β in the pathogenesis of psoriasis is well recognized. Polymorphisms in NLRP3 and caspase recruitment domain-containing protein (CARD)8, a negative regulator of caspase-1 activity, have been associated with susceptibility to common inflammatory diseases, such as Crohn's disease and rheumatoid arthritis. To investigate the role for genetic variants in the NLRP3 inflammasome in psoriasis susceptibility. In a patient sample comprising 1988 individuals from 491 families and 1002 healthy controls, genotypes for four selected single-nucleotide polymorphisms (SNPs) in NLRP3 (three SNPs) and CARD8 (one SNP) were determined by TaqMan(®) Allelic Discrimination. Using the transmission disequilibrium test (TDT), a significant increase in the transmission of the NLRP3 rs10733113G genotype to a subgroup of patients with more widespread psoriasis was demonstrated (P = 0.015). Using logistic regression analysis in 741 patients with psoriasis and 1002 controls, the CARD8 rs2043211 genotype was significantly different in cases and controls in overall terms [OR 1.3 (1.1-1.5), P = 0.004] and for both genders. Our data support the hypothesis that the inflammasome plays a role in psoriasis susceptibility.

Monogenic autoinflammatory diseases: concept and clinical manifestations

The objective of this review is to describe the clinical manifestations of the growing spectrum of monogenic autoinflammatory diseases including recently described syndromes. The autoinflammatory diseases can be grouped based on clinical findings: 1. the three classic hereditary "periodic fever syndromes", familial Mediterranean Fever (FMF); TNF receptor associated periodic syndrome (TRAPS); and mevalonate kinase deficiency/hyperimmunoglobulinemia D and periodic fever syndrome (HIDS); 2. the cryopyrin associated periodic syndromes (CAPS), comprising familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS) and neonatal-onset multisystem inflammatory disease (NOMID) or CINCA, and; 3. pediatric granulomatous arthritis (PGA); 4. disorders presenting with skin pustules, including deficiency of interleukin 1 receptor antagonist (DIRA); Majeed syndrome; pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome; deficiency of interleukin 36 receptor antagonist (DITRA); CARD14 mediated psoriasis (CAMPS), and early-onset inflammatory bowel diseases (EO-IBD); 5. inflammatory disorders caused by mutations in proteasome components, the proteasome associated autoinflammatory syndromes (PRAAS) and 6. very rare conditions presenting with autoinflammation and immunodeficiency.

Autoinflammatory gene polymorphisms and susceptibility to UK juvenile idiopathic arthritis

BACKGROUND

To investigate the autoinflammatory hereditary periodic fever syndrome genes MVK and TNFRSF1A, and the NLRP1 and IL1 genes, for association with juvenile idiopathic arthritis (JIA).

METHODS

For MVK, TNFRSF1A and NLRP1 pair-wise tagging SNPs across each gene were selected and for IL1A SNPs from a prior meta-analysis were included. 1054 UK Caucasian JIA patients were genotyped by Sequenom iPlex MassARRAY and allele and genotype frequencies compared with 5380 unrelated healthy UK Caucasian controls.

RESULTS

Four SNPs were significantly associated with UK JIA: rs2071374 within intron 4 of IL1A (ptrend=0.006), rs2228576 3' of TNFRSF1A (ptrend=0.009) and 2 SNPs, rs11836136 and rs7957619, within MVK (ptrend=0.006, ptrend=0.005 respectively). In all cases the association appeared to be driven by the systemic-onset JIA (SoJIA) subtype. Genotype data for the two MVK SNPs was available in a validation cohort of 814 JIA (oligoarticular and RF negative polyarticular) cases and 3058 controls from the US. Replication was not confirmed, however, further suggesting that this association is specific to SoJIA.

CONCLUSIONS

These findings extend the observations of the relevance of studying monogenic loci as candidates for complex diseases. We provide novel evidence of association of MVK and TNFRSF1A with UK JIA, specifically driven by association with SoJIA and further confirm that the IL1A SNP association with SoJIA is subtype specific. Replication is required in independent cohorts.

Primary immunodeficiencies of pattern recognition receptors

Primary immunodeficiencies (PIDs) are severe defects in the capacity of the host to mount a proper immune response, and are characterized by an increased susceptibility to infections. Although classical immunodeficiencies have been characterized based on broad defects in cell populations (e.g. T/B cells or polymorphonuclear leukocytes) or humoral factors (e.g. antibodies or complement), specific immune defects based on well-defined molecular targets have been described more recently. Among these, genetic defects in pattern recognition receptors (PRRs), leading to impaired recognition of invading pathogens by the innate immune system, play an important role in specific defects against human pathogens. Defects have been described in three of the major families of PRRs: the Toll-like receptors, the C-type lectin receptors and the nucleotide-binding domain leucine-rich repeat-containing receptors. By contrast, no defects in the intracellular viral receptors of the RigI helicase family have been described to date. Defects in the PRRs show a broad variation in severity, have a narrow specificity for certain classes of pathogens, and often decrease in severity with age; these characteristics distinguish them from other forms of PIDs. Their discovery has led to important insights into the pathophysiology of infections, and may offer potential novel therapeutic targets for immunotherapy.

Clinical and biochemical landmarks in systemic autoinflammatory diseases

Systemic autoinflammatory diseases are a group of inherited disorders of the innate immune system characterized by seemingly unprovoked inflammation recurring at variable intervals and involving skin, serosal membranes, joints, and gastrointestinal apparatus, with reactive amyloidosis as a possible severe long-term complication. Recent advances in genetics and molecular biology have improved our understanding of the pathogenesis of these diseases, including familial Mediterranean fever, mevalonate kinase deficiency syndrome, tumor necrosis factor receptor-associated periodic syndrome, cryopyrin-associated periodic syndromes, and hereditary pyogenic and granulomatous disorders: the vast majority of these conditions are related to the activation of the interleukin-1 pathway, which results in (or from?) a common unifying pathogenetic mechanism. Their diagnostic identification derives from the combination of clinical data, evaluation of acute phase reactants, clinical efficacy in response to specific drugs, and recognition of specific mutations in the relevant genes, although genetic tests may be unconstructive in some cases. This review will discuss clinical and laboratory clues useful for a diagnostic approach to systemic autoinflammatory diseases.

Prevalence of known mutations and a novel missense mutation (M694K) in the MEFV gene in a population from the Eastern Anatolia Region of Turkey

Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent attacks of fever and serositis. Mutations in the Mediterranean fever gene (MEFV) localized on the short arm of chromosome 16 cause FMF. Over 90 MEFV missense/nonsense mutations have been identified so far in FMF patients, mostly in the 10th exon of the gene. In this study, the molecular test results of 891 patients identified as having FMF clinical symptoms referred to Molecular Genetics Laboratory of the Department of Medical Biology and Genetics, Faculty of Medicine, Inonu University, Malatya/Turkey were retrospectively evaluated. Patients were referred by their physicians for MEFV mutation detection. The DNA fragments including hot spots within the coding sequences of the MEFV gene were amplified by PCR using genomic DNA and analyzed by pyrosequencing technique. Of the 891 patients investigated, 420 (47.13%) had at least one mutation. The most frequent mutation was E148Q, followed by M694V, M680I (G/C), P369S, V726A, R761H, A744S, M694I, K695R and F479L mutations. In addition, a novel missense mutation (M694K) was reported in seven members of a family in the course of mutation screening of patients.

A molecular analysis of familial Mediterranean fever disease in a cohort of Turkish patients

BACKGROUND AND OBJECTIVES

Familial Mediterranean fever (FMF) is an autosomal recessive disorder caused by mutations in MEFV gene, which encodes pyrin. FMF is especially prevalent among Turks, Armenians, non-Ashkenazi Jews, and Arabs. The aim of this study was to determine the frequency and spectrum of 12 MEFV mutations of these patients and any genotype-phenotype correlation in this large Turkish group.

DESIGN AND SETTING

A retrospective study at Erciyes University Medical Faculty, from January 2007 to June 2009.

PATIENTS AND METHODS

We enrolled 446 Turkish FMF patients and identified the known 12 MEFV mutations with clinical investigations. DNA was amplified by PCR and subjected to reverse hybridization for the detection of MEFV gene mutations.

RESULTS

Among the 446 patients, 103 (46.6%) had a heterozygous genotype, 44 (19.9%) had a homozygous genotype, and 74 (33.49%) had a compound heterozygous genotype. The most common mutation detected was heterozygote M694V (46/221). Of the included 446 patients, 218 (48.87%) were male and 228 (51.12%) were female. High parental consanguinity rates affect FMF development. The clinical spectrum varied with different mutation profiles.

CONCLUSIONS

This study plays an important role in detecting the distribution of MEFV mutations and determining clinical approaches among Turk FMF patients. Also, we seemed to detect a distinctive clinical picture, specifically a lower frequency of amyloidosis.

Guidelines for the genetic diagnosis of hereditary recurrent fevers

Hereditary recurrent fevers (HRFs) are a group of monogenic autoinflammatory diseases characterised by recurrent bouts of fever and serosal inflammation that are caused by pathogenic variants in genes important for the regulation of innate immunity. Discovery of the molecular defects responsible for these diseases has initiated genetic diagnostics in many countries around the world, including the Middle East, Europe, USA, Japan and Australia. However, diverse testing methods and reporting practices are employed and there is a clear need for consensus guidelines for HRF genetic testing.

Draft guidelines were prepared based on current practice deduced from previous HRF external quality assurance schemes and data from the literature. The draft document was disseminated through the European Molecular Genetics Quality Network for broader consultation and amendment. A workshop was held in Bruges (Belgium) on 18 and 19 September 2011 to ratify the draft and obtain a final consensus document. An agreed set of best practice guidelines was proposed for genetic diagnostic testing of HRFs, for reporting the genetic results and for defining their clinical significance.

Setting up TRAPS

Tumour necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) is a dominantly inherited autoinflammatory disease caused by heterozygous mutations in the TNFRSF1A gene encoding for the TNF receptor 1 (TNFR1). TRAPS is a multi-faceted and heterogeneous disease which commonly manifests as recurrent episodes of high fever accompanied by abdominal pain, pleurisy, migratory rash, and myalgia. Disease attacks occur spontaneously or may be elicited by minor triggers. Because of a vigorous and sustained acute-phase response it may be complicated by systemic AA amyloidosis. Therapeutically interleukin-1 blockade seems even more promising than TNF blockade. Studies on the pathogenesis of TRAPS have shown TNFα-dependent cellular signalling to be defective, an enigmatic finding considering the hyperinflammatory phenotype of the disease. Several studies indicate that most mutated receptors never reach the cell surface but are misfolded and trapped in the endoplasmic reticulum, where they may elicit an intracellular inflammatory response, and thus lead to constitutional expression of proinflammatory cytokines. The aim of this review is to describe the current understanding of the pathogenesis of TRAPS by integrating recent clinical and laboratory data.

Tumor necrosis factor receptor-associated periodic fever syndrome in a 58-year-old man: caution not to discount TRAPS as a diagnosis in older patients

Tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS) is a rare systemic autoinflammatory disorder characterized by recurrent episodes of fever and localized inflammation of different organs. The disease is dominantly inherited, with an onset usually in early childhood. We describe a case of a 58-year-old patient with TRAPS caused by the low-penetrance R92Q mutation in TNFRSF1A gene. The patient responded well to anti-tumor necrosis factor α therapy. Although periodic fever syndromes, including TRAPS, mainly begin in early childhood, it is important to consider periodic fever syndrome also in patient presenting at an age older than the average reported case for TRAPS.