Hyper-IgD syndrome or mevalonate kinase deficiency

A lactate-SREBP2 signaling axis drives tolerogenic dendritic cell maturation and promotes cancer progression

Conventional dendritic cells (DCs) are essential mediators of antitumor immunity. As a result, cancers have developed poorly understood mechanisms to render DCs dysfunctional within the tumor microenvironment (TME). After identification of CD63 as a specific surface marker, we demonstrate that mature regulatory DCs (mregDCs) migrate to tumor-draining lymph node tissues and suppress DC antigen cross-presentation in trans while promoting T helper 2 and regulatory T cell differentiation. Transcriptional and metabolic studies showed that mregDC functionality is dependent on the mevalonate biosynthetic pathway and its master transcription factor, SREBP2. We found that melanoma-derived lactate activates SREBP2 in tumor DCs and drives conventional DC transformation into mregDCs via homeostatic or tolerogenic maturation. DC-specific genetic silencing and pharmacologic inhibition of SREBP2 promoted antitumor CD8+ T cell activation and suppressed melanoma progression. CD63+ mregDCs were found to reside within the lymph nodes of several preclinical tumor models and in the sentinel lymph nodes of patients with melanoma. Collectively, this work suggests that a tumor lactate-stimulated SREBP2-dependent program promotes CD63+ mregDC development and function while serving as a promising therapeutic target for overcoming immune tolerance in the TME.

A SREBF2-dependent gene program drives an immunotolerant dendritic cell population during cancer progression

Dendritic cells (cDCs) are essential mediators of anti-tumor immunity. Cancers have developed mechanisms to render DCs dysfunctional within the tumor microenvironment. Utilizing CD63 as a unique surface marker, we demonstrate that mature regulatory DCs (mregDCs) suppress DC antigen cross-presentation while driving T _H 2 and regulatory T cell differentiation within tumor-draining lymph node tissues. Transcriptional and metabolic studies show that mregDC functionality is dependent upon the mevalonate biosynthetic pathway and the master transcription factor, SREBP2. Melanoma-derived lactate activates DC SREBP2 in the tumor microenvironment (TME) and drives mregDC development from conventional DCs. DC-specific genetic silencing and pharmacologic inhibition of SREBP2 promotes anti-tumor CD8 ⁺ T cell activation and suppresses melanoma progression. CD63 ⁺ mregDCs reside within the sentinel lymph nodes of melanoma patients. Collectively, this work describes a tumor-driven SREBP2-dependent program that promotes CD63 ⁺ mregDC development and function while serving as a promising therapeutic target for overcoming immune tolerance in the TME.

One Sentence Summary

The metabolic transcription factor, SREBF2, regulates the development and tolerogenic function of the mregDC population within the tumor microenvironment.

Urticaria: A Narrative Overview of Differential Diagnosis

Urticaria is an inflammatory skin disorder that may occur in isolation or associated with angioedema and/or anaphylaxis. Clinically, it is characterized by the presence of smooth, erythematous or blanching, itchy swelling, called wheals or hives, which greatly vary in size and shape and last less than 24 h before fading to leave normal skin. Urticaria is the consequence of mast-cell degranulation that can be caused by immunological or non-immunological mechanisms. From a clinical point of view, many skin conditions can mimic urticaria and their recognition is mandatory for a correct management and therapeutic approach. We have reviewed all of the main relevant studies which addressed differential diagnosis of urticarial, published until December 2022. The National Library of Medicine PubMed database was used for the electronic research. The present review offers a clinical narrative overview, based on the available literature, of the principal skin disorders that can be misdiagnosed as urticaria (mainly autoinflammatory or autoimmune disorders, drug-induced reactions, and hyperproliferative diseases). The aim of this review is to provide clinicians a useful tool for correctly suspecting and identifying all of these conditions.

Therapies Targeting Trained Immune Cells in Inflammatory and Autoimmune Diseases

The concept of trained immunity has recently emerged as a mechanism contributing to several immune mediated inflammatory conditions. Trained immunity is defined by the immunological memory developed in innate immune cells after a primary non-specific stimulus that, in turn, promotes a heightened inflammatory response upon a secondary challenge. The most characteristic changes associated to this process involve the rewiring of cell metabolism and epigenetic reprogramming. Under physiological conditions, the role of trained immune cells ensures a prompt response. This action is limited by effective resolution of inflammation and tissue repair in order to restore homeostasis. However, unrestrained activation of innate immune cells contributes to the development of chronic inflammation and tissue destruction through the secretion of inflammatory cytokines, proteases and growth factors. Therefore, interventions aimed at reversing the changes induced by trained immunity provide potential therapeutic approaches to treat inflammatory and autoimmune diseases like rheumatoid arthritis (RA). We review cellular approaches that target metabolism and the epigenetic reprogramming of dendritic cells, macrophages, natural killer cells, and other trained cells in the context of autoimmune inflammatory diseases.

Cholesterol partially rescues the inhibition effect of pravastatin on keratinocytes proliferation by regulating cell cycle relative proteins through AKT and ERK pathway

Mevalonate pathway plays a key role in skin physiological process in human. Recently, it has been reported that mutation of some genes in the mevalonate pathway cause disseminated superficial actinic porokeratosis (DSAP). But the pathogenesis is still unknown. Pravastatin (PRA), one of HMG-CoA reductase (HMGCR) inhibitors, has been found to inhibit cells proliferation, including keratinocytes (KCs). In this study, we use PRA to block the mevalonate pathway in KCs with or without the down-stream intermediate products replenishment. The results demonstrated that PRA strongly inhibited proliferation of KCs and caused the G₀ /G₁ arrest. When some down-stream intermediate products were added, only cholesterol (CH) could partially rescue the inhibition effect of PRA on KCs proliferation, but not other products, such as mevalonic acid, farnesyl pyrophosphate or geranylgeranyl pyrophosphate. Mechanistic analysis revealed that PRA down-regulated expression of cyclin B1, but up-regulated cyclin E and p21 expression. And PRA increased the phosphorylation level of Protein Kinase B (AKT) but decreased the phosphorylation level of Extracellular Signal Regulated Kinase (ERK1/2). CH could attenuate the elevated cyclin E and activated AKT induced by PRA. These results indicated that CH could rescue the proliferation inhibition of KCs caused by PRA, which laid a foundation for elucidating the pathogenesis of DSAP clearly.

Current and future advances in genetic testing in systemic autoinflammatory diseases

Systemic autoinflammatory diseases (SAIDs) are a group of inflammatory disorders caused by dysregulation in the innate immune system that leads to enhanced immune responses. The clinical diagnosis of SAIDs can be difficult since individually these are rare diseases with considerable phenotypic overlap. Most SAIDs have a strong genetic background, but environmental and epigenetic influences can modulate the clinical phenotype. Molecular diagnosis has become essential for confirmation of clinical diagnosis. To date there are over 30 genes and a variety of modes of inheritance that have been associated with monogenic SAIDs. Mutations in the same gene can lead to very distinct phenotypes and can have different inheritance patterns. In addition, somatic mutations have been reported in several of these conditions. New genetic testing methods and databases are being developed to facilitate the molecular diagnosis of SAIDs, which is of major importance for treatment, prognosis and genetic counselling. The aim of this review is to summarize the latest advances in genetic testing for SAIDs and discuss potential obstacles that might arise during the molecular diagnosis of SAIDs.

Biochemistry of Autoinflammatory Diseases: Catalyzing Monogenic Disease

Monogenic autoinflammatory disorders are a group of conditions defined by systemic or localized inflammation without identifiable causes, such as infection. In contrast to classical primary immunodeficiencies that manifest with impaired immune responses, these disorders are due to defects in genes that regulate innate immunity leading to constitutive activation of pro-inflammatory signaling. Through studying patients with rare autoinflammatory conditions, novel mechanisms of inflammation have been identified that bare on our understanding not only of basic signaling in inflammatory cells, but also of the pathogenesis of more common inflammatory diseases and have guided treatment modalities. Autoinflammation has further been implicated as an important component of cardiovascular, neurodegenerative, and metabolic syndromes. In this review, we will focus on a subset of inherited enzymatic deficiencies that lead to constitutive inflammation, and how these rare diseases have provided insights into diverse areas of cell biology not restricted to immune cells. In this way, Mendelian disorders of the innate immune system, and in particular loss of catalytic activity of enzymes in distinct pathways, have expanded our understanding of the interplay between many seemingly disparate cellular processes. We also explore the overlap between autoinflammation, autoimmunity, and immunodeficiency, which has been increasingly recognized in patients with dysregulated immune responses.

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis syndrome - PFAPA syndrome

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is a complex autoinflammatory disease with a clinical phenotype characterised by recurrent episodes of fever, systemic inflammation and symptoms and signs depicted in disease acronym. Although PFAPA is the most common autoinflammatory disease among children in many parts of the world, the condition is still an enigma, which include the regular episodes, the prompt responses to corticosteroids, the genetic bases for the familial clustering and therapeutic effects of tonsillectomy. This review explores PFAPA syndrome with the aim of describing the current clinical and scientific understanding of the condition.

Canakinumab for the treatment of hyperimmunoglobulin D syndrome

INTRODUCTION

Mevalonate Kinase Deficiency (MKD) is a rare monogenic autoinflammatory disorder (AID) with autosomal recessive inheritance caused by mutations in the MVK gene. It includes hyperimmunoglobulinemia D syndrome (HIDS) and mevalonic aciduria (a severe form). Patients have recurrent inflammatory attacks with high fever, gastrointestinal symptoms, lymphadenopathy, splenomegaly, arthralgia, rash, pharyngitis, aphtosis and constitutional complaints. Heightened understanding of molecular mechanisms in monogenic autoinflammatory disorders has provided tools for targeted treatment. HIDS is an extrinsic inflammasomopathy and is responsive to anti-IL-1 therapies, such as the recombinant IL-1-receptor antagonist anakinra, the monoclonal antibody against IL-1b canakinumab (CAN), and the recombinant IL-1R fusion protein rilonacept. Areas covered: CAN is a human monoclonal anti-IL-1β antibody that binds with high affinity and neutralizes the activity of IL-1 β. Both observational registries and some case reports have seemed promising in the efficacy of CAN in the HIDS treatment. Two clinical trials have corroborated CAN as an effective and safe drug. Expert commentary: CAN is effective and safe for the treatment of HIDS patients. Some data suggest these patients may need higher dosage or shorter dosing interval than other AIDs, to achieve and maintain complete clinical and laboratory response. Reported adverse events were mild, most often non-complicated infections.

Anakinra Therapy for Non-cancer Inflammatory Diseases

Interleukin-1 (IL-1) is the prototypical inflammatory cytokine: two distinct ligands (IL-1α and IL-1β) bind the IL-1 type 1 receptor (IL-1R1) and induce a myriad of secondary inflammatory mediators, including prostaglandins, cytokines, and chemokines. IL-1α is constitutively present in endothelial and epithelial cells, whereas IL-1β is inducible in myeloid cells and released following cleavage by caspase-1. Over the past 30 years, IL-1-mediated inflammation has been established in a broad spectrum of diseases, ranging from rare autoinflammatory diseases to common conditions such as gout and rheumatoid arthritis (RA), type 2 diabetes, atherosclerosis, and acute myocardial infarction. Blocking IL-1 entered the clinical arena with anakinra, the recombinant form of the naturally occurring IL-1 receptor antagonist (IL-1Ra); IL-1Ra prevents the binding of IL-1α as well as IL-1β to IL-1R1. Quenching IL-1-mediated inflammation prevents the detrimental consequences of tissue damage and organ dysfunction. Although anakinra is presently approved for the treatment of RA and cryopyrin-associated periodic syndromes, off-label use of anakinra far exceeds its approved indications. Dosing of 100 mg of anakinra subcutaneously provides clinically evident benefits within days and for some diseases, anakinra has been used daily for over 12 years. Compared to other biologics, anakinra has an unparalleled record of safety: opportunistic infections, particularly Mycobacterium tuberculosis, are rare even in populations at risk for reactivation of latent infections. Because of this excellent safety profile and relative short duration of action, anakinra can also be used as a diagnostic tool for undefined diseases mediated by IL-1. Although anakinra is presently in clinical trials to treat cancer, this review focuses on anakinra treatment of acute as well as chronic inflammatory diseases.

Treatment of Inflammatory Diseases with IL-1 Blockade

Background

Autoinflammatory diseases are distinct from autoimmune diseases. Whereas autoinflammatory diseases are due to dysfunctional T-cells and B-cells, autoinflammatory diseases are due to overproduction of macrophage cytokines particularly interleukin-1 beta (IL-1β). A causative role for IL-1 in autoinflammatory diseases is derived from clinical studies blocking the IL-1 receptor or neutralizing monoclonal antibodies or soluble receptors.

Methods

A review was performed of clinical trials in autoinflammatory diseases using the IL-1 receptor antagonist (anakinra), the soluble IL-1 receptor (rilonacept), antibodies to IL-1β (canakinumab, gevokizumab) and anti-IL-1α (xilonix).

Findings

Anakinra blocks the IL-1 Receptor type 1 (IL-1R1) and therefore blocks the activities of both IL-1α and IL-1β. Off-label use of anakinra is common for a broad spectrum of inflammatory diseases. Neutralization of IL-1β is used to treat hereditary autoinflammatory diseases but also atherosclerosis. Rilonacept reduces arterial wall inflammation in patients with chronic kidney disease. Neutralization of IL-1α has prolonged life in patients with advanced metastatic colorectal cancer. Compared to other cytokine blocking therapies, reducing the activities of IL-1 has an excellent safety record.

Conclusions

Blocking IL-1 therapies can be used to treat a wide-spectrum of acute and chronic inflammatory diseases.

Disorder of the mevalonate pathway inhibits calcium-induced differentiation of keratinocytes

Mutation of genes encoding the enzymes of the mevalonate pathway cause a variety of diseases, including skin disorders. Mutation of four genes in this pathway, including mevalonate kinase, phosphomevalonate kinase, mevalonate diphosphate decarboxylase and farnesyl diphosphate synthase, have demonstrated to be responsible for porokeratosis (PK). However, the pathogenesis of PK remains unclear. In the present study, specific enzyme inhibitors of the mevalonate pathway, including pravastatin (PRA), alendronate (ALD), farnesyl transferase inhibitor (FTI‑277) and geranylgeranyl transferase inhibitor (GGTI‑298), were used to investigate the effect on differentiation of keratinocytes (KCs). Western blotting demonstrated that PRA, ALD, FTI‑277 or GGTI‑298 alone, or in combination, inhibited the expression level of calcium‑induced differentiation maker involucrin (INV) in KCs. ALD and PRA induced greater inhibition of INV compared with FTI‑277 and GGTI‑298 treatment. These inhibitors additionally influenced the expression levels of keratin1. Mechanistic studies revealed that treatment of cells with inhibitors decreased the expression levels of p53 and Notch1, and regulated activation of the mitogen activated protein kinase and phosphoinositide‑3‑kinase/protein kinase B signaling pathways. The results of the present study suggested that regulation of the mevalonate pathway may be necessary for differentiation of KCs, and the pathogenesis of disseminated superficial actinic PK.

The challenge of autoinflammatory syndromes: with an emphasis on hyper-IgD syndrome

Autoinflammatory syndromes are disorders with an exaggerated inflammatory response, mostly in the absence of an appropriate trigger. Prototypic autoinflammatory syndromes are FMF, hyper-IgD syndrome (also known as mevalonate kinase deficiency), TNF receptor-associated periodic syndrome and cryopyrin-associated periodic syndrome. The clinical phenotypes partly overlap (with fever and acute phase response), but also differ between the various syndromes (e.g. regarding fever pattern, episodic vs chronic inflammation and accompanying clinical signs). In recent years, the genetic basis of quite a number of these relatively rare and mostly hereditary disorders has been elucidated. These genetic defects lead to either enhanced production of inflammatory mediators or to a lack of inhibition of these components of the innate immune system. Among these dysregulated inflammatory mediators, the pro-inflammatory cytokine IL-1β stands out. Hence, targeted treatment with blockers of IL-1 action, such as recombinant IL-1 receptor antagonist (IL-1Ra, anakinra) and mAb against IL-1β has met with impressive clinical results. In this article, hyper-IgD syndrome is discussed in more detail, based on 30 years of experience with this syndrome.

When to Suspect Autoinflammatory/Recurrent Fever Syndromes

Autoinflammatory disorders are disorders characterized by rash, arthritis, fever, and systemic inflammation. These disorders are caused by mutations in genes important in innate immune system sensors. This review highlights the workup of an individual with recurrent episodes of inflammation, features of these disorders, the genetic defects that cause these disorders, and the specific treatments available.

Biologics for Targeting Inflammatory Cytokines, Clinical Uses, and Limitations

Proinflammatory cytokines are potent mediators of numerous biological processes and are tightly regulated in the body. Chronic uncontrolled levels of such cytokines can initiate and derive many pathologies, including incidences of autoimmunity and cancer. Therefore, therapies that regulate the activity of inflammatory cytokines, either by supplementation of anti-inflammatory recombinant cytokines or by neutralizing them by using blocking antibodies, have been extensively used over the past decades. Over the past few years, new innovative biological agents for blocking and regulating cytokine activities have emerged. Here, we review some of the most recent approaches of cytokine targeting, focusing on anti-TNF antibodies or recombinant TNF decoy receptor, recombinant IL-1 receptor antagonist (IL-1Ra) and anti-IL-1 antibodies, anti-IL-6 receptor antibodies, and TH17 targeting antibodies. We discuss their effects as biologic drugs, as evaluated in numerous clinical trials, and highlight their therapeutic potential as well as emphasize their inherent limitations and clinical risks. We suggest that while systemic blocking of proinflammatory cytokines using biological agents can ameliorate disease pathogenesis and progression, it may also abrogate the hosts defense against infections. Moreover, we outline the rational need to develop new therapies, which block inflammatory cytokines only at sites of inflammation, while enabling their function systemically.

Practice parameter for the diagnosis and management of primary immunodeficiency

The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) have jointly accepted responsibility for establishing the "Practice parameter for the diagnosis and management of primary immunodeficiency." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Treating rheumatological diseases and co-morbidities with interleukin-1 blocking therapies

The inflammatory cytokines IL-1α and IL-1β orchestrate local and systemic inflammatory responses underlying a broad spectrum of diseases. Three agents for reducing IL-1 activities are currently available. Anakinra is a recombinant form of the naturally occurring IL-1 receptor antagonist. Anakinra binds to the IL-1 receptor and prevents the activity of IL-1α and IL-1β. The soluble decoy receptor rilonacept and the neutralizing mAb canakinumab block IL-1β. A mAb directed against the IL-1 receptor and a neutralizing anti-human IL-1α are in clinical trials. The availability of therapies specifically targeting IL-1 unveiled the pathological role of IL-1-mediated inflammation in a broadening list of diseases. Conditions effectively treated with agents blocking IL-1 range from classic rheumatic diseases, such as RA and gout, to autoinflammatory syndromes, such as systemic JIA and FMF. However, IL-1 antagonism is also effective against highly prevalent inflammatory diseases, namely cardiovascular diseases and type 2 diabetes, conditions that are frequently encountered as co-morbidities in patients with rheumatic diseases. Thereby, IL-1 inhibition has the potential to lift the burden of disease for patients with rheumatic conditions, but also to provide clinical benefits beyond the efficacy on osteoarticular manifestations.

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.

A clinical guide to autoinflammatory diseases: familial Mediterranean fever and next-of-kin

Autoinflammatory diseases are associated with abnormal activation of the innate immune system, leading to clinical inflammation and high levels of acute-phase reactants. The first group to be identified was the periodic fever diseases, of which familial Mediterranean fever (FMF) is the most common. In FMF, genetic results are not always straightforward; thus, flowcharts to guide the physician in requesting mutation analyses and interpreting the findings are presented in this Review. The other periodic fever diseases, which include cryopyrin-associated periodic syndromes (CAPS), TNF receptor-associated periodic syndrome (TRAPS) and mevalonate kinase deficiency/hyperimmunoglobulin D syndrome (MKD/HIDS), have distinguishing features that should be sought for carefully during diagnosis. Among this group of diseases, increasing evidence exists for the efficacy of anti-IL-1 treatment, suggesting a major role of IL-1 in their pathogenesis. In the past decade, we have started to learn about the other rare autoinflammatory diseases in which fever is less pronounced. Among them are diseases manifesting with pyogenic lesions of the skin and bone; diseases associated with granulomatous lesions; diseases associated with psoriasis; and diseases associated with defects in the immunoproteasome. A better understanding of the pathogenesis of these autoinflammatory diseases has enabled us to provide targeted biologic treatment at least for some of these conditions.

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.

Mevalonate kinase genotype in children with recurrent fevers and high serum IgD level

In selected cases, childhood's recurrent fevers of unknown origin can be referred to systemic autoinflammatory diseases as mevalonate kinase deficiency (MKD), caused by mutations in the mevalonate kinase gene (MVK), previously named "hyper-IgD syndrome" due to its characteristic increase in serum IgD level. There is no clear evidence for studying MVK genotype in these patients. From a cohort of 305 children evaluated for recurrent fevers in our outpatient clinic during the decade 2001-2011, we have retrospectively selected 10 unrelated Italian children displaying febrile episodes, associated with recurrent inflammatory signs (variably involving gastrointestinal tube, joints, lymph nodes, and skin) and persistently increased serum IgD levels. All these patients were examined for MVK genotype: only 2 presented bonafide MVK mutations, 5 showed the same S52N MVK polymorphism, while the remaining 3 had a wild-type MVK sequence. Clinical details of these patients have been reviewed through the critical analysis of their medical charts. Our report underscores the pitfalls of MKD diagnosis based on clinical grounds and IgD levels, emphasizing the uncertain contribution of MVK polymorphisms in the diagnostic assessment of the syndrome.

How not to miss autoinflammatory diseases masquerading as urticaria

Urticarial skin reactions are one of the most frequent problems seen by allergists and clinical immunologists in daily practice. The most common reason for recurrent wheals is spontaneous urticaria. There are, however, several less common diseases that present with urticarial rash, such as urticarial vasculitis and autoinflammatory disorders. The latter include cryopyrin-associated periodic syndrome and Schnitzler's syndrome, both rare and disabling conditions mediated by increased interleukin-1 secretion. Apart from the urticarial rash, patients are suffering from a variety of systemic symptoms including recurrent fever attacks, arthralgia or arthritis and fatigue. Autoinflammatory diseases are often associated with a diagnostic delay of many years and do not respond to antihistamines and other treatments of urticaria. Also, the chronic inflammation may lead to long-term complications such as amyloidosis. It is therefore important not to miss these diseases when diagnosing and treating patients with chronic recurrent urticarial rash. Here, we present clinical clues and tips that can help to identify autoinflammatory disorders in patients presenting with chronic urticarial rash and discuss their clinical picture and management.

Hereditäre Fiebersyndrome

Das familiäre Mittelmeerfieber (FMF), Hyper-IgD-Syndrom (HIDS) und das Tumornekrosefaktor(TNF)-Rezeptor-1-assoziierte periodische Syndrom (TRAPS) sind monogene Krankheiten, die unter dem Begriff der hereditären Fiebersyndrome zusammengefasst werden. Sie sind durch rezidivierende Episoden mit Fieber und Entzündungszeichen gekennzeichnet und werden von Mutationen in Genen verursacht, denen eine Funktion bei der angeborenen Immunität zukommt. Die vorliegende Übersichtsarbeit befasst sich mit dem klinischen Erscheinungsbild und der Genetik der hereditären Fiebersyndrome. Sie sind für die humangenetische Beratung von Bedeutung.

Treating inflammation by blocking interleukin-1 in a broad spectrum of diseases

Interleukin-1 (IL-1) is a highly active pro-inflammatory cytokine that lowers pain thresholds and damages tissues. Monotherapy blocking IL-1 activity in autoinflammatory syndromes results in a rapid and sustained reduction in disease severity, including reversal of inflammation-mediated loss of sight, hearing and organ function. This approach can therefore be effective in treating common conditions such as post-infarction heart failure, and trials targeting a broad spectrum of new indications are underway. So far, three IL-1-targeted agents have been approved: the IL-1 receptor antagonist anakinra, the soluble decoy receptor rilonacept and the neutralizing monoclonal anti-IL-1β antibody canakinumab. In addition, a monoclonal antibody directed against the IL-1 receptor and a neutralizing anti-IL-1α antibody are in clinical trials.