Key facts and hot spots on tumor necrosis factor receptor-associated periodic syndrome

A Theoretical Link Between the GH/IGF-1 Axis and Cytokine Family in Children: Current Knowledge and Future Perspectives

BACKGROUND/OBJECTIVES

Growth in childhood and adolescence is influenced by a complex interaction of genetic, environmental, and hormonal factors, with growth hormone (GH) and insulin-like growth factor 1 (IGF-1) playing crucial roles in linear growth and development. However, chronic inflammation, often detected in situations like inflammatory bowel disease and juvenile idiopathic arthritis, can significantly disrupt the GH/IGF-1 axis, causing a relevant growth impairment.

METHODS

We conducted a retrospective review focusing on the role of cytokines in the GH-IGF-1 axis and growth.

RESULTS

Inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 have been shown to contribute to GH resistance through an array of mechanisms that involve the downregulation of GH receptors and alterations in IGF-1 metabolism. This disruption negatively impacts the growth plate, particularly by impairing chondrocyte proliferation and differentiation, which are essential for proper bone elongation. This review delves into the intricate relationship among growth, chronic inflammation, and GH-IGF-1 axis, emphasizing the contribution of inflammatory cytokines in modulating GH signaling. It also highlights how cytokines can interfere with the molecular pathways that regulate skeletal growth, ultimately leading to growth disturbances in children suffering from chronic inflammatory diseases.

CONCLUSIONS

The findings underscore the importance of controlling inflammation in affected individuals to mitigate its detrimental effects on growth and ensure that children may reach their growth full potential.

The Multifaceted Complexity of Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS): A Case Report Highlighting Atypical Gastrointestinal Manifestations

BACKGROUND

Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS) is an autosomal dominant autoinflammatory disorder stemming from mutations in the TNFRSF1A gene affecting the tumor necrosis factor receptor (TNFR)-1. These mutations lead to dysregulated inflammatory responses, primarily mediated by augmented interleukin (IL)-1β release.

CASE PRESENTATION

We present the case of a 29-year-old woman with a history of recurrent febrile episodes, abdominal pain, and joint manifestations, eventually diagnosed with TRAPS following genetic testing revealing a heterozygous R92Q mutation in TNFRSF1A. Further genetic examinations unveiled additional clinically significant mutations, complicating the clinical picture. Our patient exhibited delayed colonic transit time and right colonic amyloidosis, a rare complication. Surgical intervention was required for overwhelming intestinal obstruction, revealing mucosal atrophy and dense lymphocytic infiltrates on histological examination.

DISCUSSION

Gastrointestinal involvement in TRAPS is common but can present diagnostic challenges. Following colon resection, histological examination revealed amyloid deposition, underscoring the importance of a comprehensive evaluation of these patients. Isolated colic amyloidosis has significant diagnostic and prognostic implications, warranting cautious monitoring and tailored management strategies. Treatment of TRAPS typically involves anti-inflammatory agents such as IL-1 inhibitors, with our patient experiencing clinical improvement on anakinra and canakinumab.

CONCLUSION

This case report emphasizes the diverse manifestations of TRAPS and the importance of recognizing gastrointestinal complications, particularly isolated colic amyloidosis. Comprehensive evaluation, including histological examination, is crucial for identifying atypical disease presentations and guiding management decisions. Continued research is needed to elucidate the underlying mechanisms and optimize treatment strategies for TRAPS and its associated complications.

A Potential Partnership between Genetics and the Oral Microbiome in Children Displaying Periodic Fever/Aphthosis/Pharyngitis/Adenitis Syndrome

Periodic fever/aphthosis/pharyngitis/adenitis (PFAPA) syndrome was initially described in a small cohort of American children [...].

What General Neurologists Should Know about Autoinflammatory Syndromes?

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

A patient with tumor necrosis factor receptor-associated periodic syndrome misdiagnosed as Kawasaki disease: A case report and literature review

This article reports a case of tumor necrosis factor receptor-associated periodic syndrome (TRAPS) misdiagnosed as Kawasaki disease and summarizes the clinical features and therapeutic progress of TRAPS and the relationship between its clinical manifestations and gene mutations. We retrospectively analyzed a patient with tumor necrosis factor receptor superfamily member 1A (TNFRSF1A) -mutated auto-inflammatory disease who was misdiagnosed with Kawasaki disease in another hospital. The clinical features and therapeutic progress of TRAPS were analyzed by combining clinical features and gene reports of this case and literature review. TRAPS onset occurred in a female pediatric patient at the age of 4 months. The child and in his father at the age of 6 years, both of whom manifested periodic fever, and recurrent rash, as well as elevated leukocytes, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) during episodes but normal between episodes. This child carried a heterozygous mutation in TNFRSF1A located in the region 6442923-6442931 on chromosome 12. The nucleic acid alteration was: c.298 (exon3) _c.306 (exon3) 291 delCTCAGCTGC, resulting in a 3 amino acid deletion p.L100_C 102del 292 (p.Leu100_Cys102del) (NM_001065). After etanercept treatment, the symptoms of fever and rash disappeared, and the levels of ESR, CRP, interleukin (IL)-1, IL-6, and TNF-α levels were normal. Subsequently, no liver, kidney, or cardiac amyloidosis and severe etanercept-related adverse events were observed at 1-year follow-up. TRAPS pathogenesis is associated with TNFRSF1A mutation, which is characterized by periodic episodes of fever, mostly accompanied by recurrent rashes, periorbital edema, abdominal pain, and serious complications of organ amyloidosis. Moreover, etanercept can effectively alleviate the clinical symptoms and high inflammation level of TRAPS.

An Update on Reports of Atypical Presentations of Kawasaki Disease and the Recognition of IVIG Non-Responder Children

Kawasaki disease (KD) is an acute vasculitis with an intrinsic risk of severe involvement of coronary arteries. The worldwide spread of KD and the importance of early diagnosis for preventing cardiovascular complications have ascertained the need for updating guidelines for prompt disease recognition and treatment efficacy assessment. All KD patients who comply with the definition of classic or atypical disease should be treated with intravenous immunoglobulin (IVIG) soon after diagnosis. The objective of our narrative review was to analyze the medical literature about case reports with atypical KD in relation to diagnosis and potential identification of predictors of non-responsiveness to IVIG. Our analysis has shown that the seminal challenge in KD management is the timeliness of diagnosis, although both extreme variability and transience of clinical manifestations make this goal difficult. A non-negligible percentage of patients, especially in the first 6 months of life, might have atypical manifestations of KD, whose painstaking differential diagnosis may be tricky. Many attempts to develop universal scoring systems and detect children at higher risk of IVIG resistance have been rather unsuccessful. Additionally, KD may show different evolutions according to unraveled demographic, genetic, or epigenetic factors. Further research is needed to elucidate all open questions about KD and clarify the long-term outcome of its potential complications.

Clinical impact and disease evolution of SARS-CoV-2 infection in familial Mediterranean fever

The innate immune system is critically involved in the pathogenesis of familial Mediterranean fever (FMF), characterized by dysregulated inflammasome activity and recurrent inflammatory attacks: this is the most common among monogenic autoinflammatory diseases, which shares some biochemical pathways with the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection. In this short review we explore the overlap in the pathophysiology of FMF and SARS-CoV-2 infection, discussing how to understand better the interaction between the two diseases and optimize management. A poorer outcome of SARS-CoV-2 infection seems not to be present in infected FMF patients in terms of hospitalization time, need for oxygen support, need for intensive care, rate of complications and exitus. Long-term surveillance will confirm the relatively low risk of a worse prognosis observed so far in SARS-CoV-2-infected people with FMF. In these patients COVID-19 vaccines are recommended and their safety profile is expected to be similar to the general population.

The Clinical Chameleon of Autoinflammatory Diseases in Children

The very first line of defense in humans is innate immunity, serving as a critical strongpoint in the regulation of inflammation. Abnormalities of the innate immunity machinery make up a motley group of rare diseases, named 'autoinflammatory', which are caused by mutations in genes involved in different immune pathways. Self-limited inflammatory bouts involving skin, serosal membranes, joints, gut and other districts of the human body burst and recur with variable periodicity in most autoinflammatory diseases (ADs), often leading to secondary amyloidosis as a long-term complication. Dysregulated inflammasome activity, overproduction of interleukin (IL)-1 or other IL-1-related cytokines and delayed shutdown of inflammation are pivotal keys in the majority of ADs. The recent progress of cellular biology has clarified many molecular mechanisms behind monogenic ADs, such as familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome (or 'autosomal dominant familial periodic fever'), cryopyrin-associated periodic syndrome, mevalonate kinase deficiency, hereditary pyogenic diseases, idiopathic granulomatous diseases and defects of the ubiquitin-proteasome pathway. A long-lasting history of recurrent fevers should require the ruling out of chronic infections and malignancies before considering ADs in children. Little is known about the potential origin of polygenic ADs, in which sterile cytokine-mediated inflammation results from the activation of the innate immunity network, without familial recurrency, such as periodic fever/aphthous stomatitis/pharyngitis/cervical adenopathy (PFAPA) syndrome. The puzzle of febrile attacks recurring over time with chameleonic multi-inflammatory symptoms in children demands the inspection of the mixture of clinical data, inflammation parameters in the different disease phases, assessment of therapeutic efficacy of a handful of drugs such as corticosteroids, colchicine or IL-1 antagonists, and genotype analysis to exclude or confirm a monogenic origin.

Assessment of Congenital Neutropenia in Children: Common Clinical Sceneries and Clues for Management

A disparate group of rare hematological diseases characterized by impaired maturation of neutrophil granulocytes defines congenital neutropenias. Neutropenic patients are prone to recurrent infections beginning in the first months of life. Of interest is "cyclic neutropenia," an ultra-rare disorder revealed by sinusoidal variations in the neutrophil count and recurring infections every 21 days. Diagnosis of these disorders is frequently obscured by the multiple causes of recurrent fevers in children. The aim of this overview is to outline the physical assessment of children presenting with early-onset symptomatic neutropenia, identify the disease between the many medical conditions and even emergencies which should enter in differential diagnosis, hint at the potential management with granulocyte-colony stimulating factor, define the risk of evolution to hematologic malignancy, and summarize inter-professional team strategies for improving care coordination and outcomes of patients.

The everchanging framework of autoinflammation

The innate immunity works as a defence bullwark that safeguards healthy tissues with the power of detecting infectious agents in the human body: errors in the context of innate immunity identify autoinflammatory disorders (AIDs), which arise as bouts of aberrant inflammation with little or no involvement of T and B cells and neither recognized infections, nor associated autoimmune phenomena. Hereditary AIDs tend to have a pediatric-onset heralded by stereotyped inflammatory symptoms and fever, while AIDs without an ascertained cause, such as systemic juvenile idiopathic arthritis, derive from the interaction of genetic factors with environmental noxae and are unevenly defined. A dysregulated inflammasome activation promotes the best-known family of AIDs, as well as several degenerative and metabolic disorders, but also nuclear factor κB- and interferon-mediated conditions have been framed as AIDs: the zenith of inflammatory flares marks different phenotypes, but diagnosis may go unnoticed until adulthood due to downplayed symptoms and complex kaleidoscopic presentations. This review summarizes the main AIDs encountered in childhood with special emphasis on the clinical stigmata that may help establish a correct framework and blueprints to empower young scientists in the recognition of AIDs. The description focuses inflammasomopathies as paradigms of interleukinopathies, nuclear factor-κB -related disorders and interferonopathies. The challenges in the management of AIDs during childhood have been recently boosted by numerous therapeutic options derived from genomically-based approaches, which have led to identify targeted biologic agents as rationalized treatments and achieve more tangible perspectives of disease control.

Anakinra and canakinumab for patients with R92Q-associated autoinflammatory syndrome: a multicenter observational study from the AIDA Network

BACKGROUND

This study aims at describing the therapeutic outcome of patients carrying the R92Q variant in the TNFRSF1A gene treated with anakinra (ANA) or canakinumab (CAN) and identifying any factors predictive of complete response to IL-1 inhibition.

METHODS

Clinical data of patients treated with ANA or CAN for recurrent inflammatory attacks due to the presence of the R92Q variant were retrospectively collected and analysed.

RESULTS

Data about 20 treatment courses with IL-1 inhibitors (16 with ANA and 4 with CAN) from 19 patients were collected. Mean age at disease onset was 20.2 ± 14.8 years. In 5 cases (26%) the R92Q variant was found in a family member affected by recurrent fever. The therapeutic response was complete in 13(68%) and partial in 2 patients (11%); treatment failure was observed in 4 cases (21%). Median AIDAI decreased from 10 (interquartile range [IQR] = 28) to 0 (IQR = 1) at the 12-month follow-up visit (p < 0.001). Mean ESR and median CRP dropped respectively from 40.8 ± 24.8 to 9.1 ± 4.5 mm/h (p < 0.001) and from 3.0 (IQR = 1.9) to 0.3 (IQR = 0.3) mg/dl (p < 0.001) after 12 months of treatment. A steroid-sparing effect was observed from the third month of treatment (p < 0.01). Thirteen patients (65%) were still on treatment at the last follow-up visit (median duration of treatment 17 (IQR = 38) months). The presence of R92Q mutation in a symptomatic relative (p = 0.022), the relapsing remitting disease course (p < 0.001) and the presence of migratory erythematous skin rashes during fever attacks (p = 0.005) were associated with complete efficacy of IL-1 inhibitors.

CONCLUSIONS

R92Q patients showed a favourable response to ANA and CAN, particularly when the mutation segregated in a family member and when a relapsing-remitting disease course or TNF-α receptor-associated periodic syndrome (TRAPS) typical skin rash were observed. In the subgroup of patients not taking advantage of IL-1 blockage different molecular mechanisms underlying the autoinflammatory picture are likely to exist.

Biotechnological Agents for Patients With Tumor Necrosis Factor Receptor Associated Periodic Syndrome-Therapeutic Outcome and Predictors of Response: Real-Life Data From the AIDA Network

Objective: To describe the role of biotechnological therapies in patients with tumor necrosis factor receptor associated periodic syndrome (TRAPS) and to identify any predictor of complete response. Methods: Clinical, laboratory, and therapeutic data from 44 Caucasian TRAPS patients treated with biologic agents were retrospectively collected in 16 Italian tertiary Centers. Results: A total of 55 biological courses with anakinra (n = 26), canakinumab (n = 16), anti-TNF-α agents (n = 10), and tocilizumab (n = 3) were analyzed. A complete response was observed in 41 (74.5%) cases, a partial response in 9 (16.4%) cases and a treatment failure in 5 (9.1%) cases. The frequency of TRAPS exacerbations was 458.2 flare/100 patients-year during the 12 months prior to the start of biologic treatment and 65.7 flare/100 patients-years during the first 12 months of therapy (p < 0.0001). The median duration of attacks was 5.00 (IQR = 10.50) days at the start of biologics and 1.00 (IQR = 0.00) days at the 12-month assessment (p < 0.0001). Likewise, a significant reduction was observed in the Autoinflammatory Disease Activity Index during the study period (p < 0.0001). A significant corticosteroid sparing effect was observed as early as the first 12 months of treatment both in the number of patients requiring corticosteroids (p = 0.025) and in the dosages employed (p < 0.0001). A significant reduction was identified in the erythrocyte sedimentation rate (p < 0.0001), C reactive protein (p < 0.0001), serum amyloid A (p < 0.0001), and in the 24-h proteinuria dosage during follow-up (p = 0.001). A relapsing-remitting disease course (OR = 0.027, C.I. 0.001-0.841, p = 0.040) and the frequency of relapses at the start of biologics (OR = 0.363, C.I. 0.301-0.953, p = 0.034) were significantly associated with a complete response. No serious adverse events were observed. Conclusions: Treatment with biologic agents is highly effective in controlling clinical and laboratory TRAPS manifestations. Patients with a relapsing-remitting course and a lower frequency of flares at the start of treatment show more likely a complete response to biologic agents.

The autoinflammatory side of recurrent pericarditis: Enlightening the pathogenesis for a more rational treatment

Recurrent pericarditis (RP) is a troublesome and debilitating complication of acute pericarditis. Although the etiopathogenesis of this condition remains unknown, an intricate overlap of autoimmune and autoinflammatory pathways has been hypothesized to explain its beginning and recurrence over time. The majority of cases are defined as "idiopathic", reflecting our awkwardness to unravel the intimate mechanisms of RP. Given the possible occurrence of anti-nuclear, anti-heart and anti-intercalated disk antibodies as well as the association with peculiar human leukocyte antigen haplotypes, an autoimmune contribution has been claimed to specify the nature of RP. However, the most innovative pathogenic scenario of RP has been conferred to the innate immune system, mainly involving neutrophils and macrophages that produce a large amount of interleukin (IL)-1 via inflammasome activation. The clinical resemblance of RP with autoinflammatory diseases that may be marked by symptomatic serositis, high fevers and strikingly increased inflammatory parameters further suggests a similar inflammasome-mediated pathogenesis. Aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) remain the mainstay of therapy in RP, whereas colchicine is recommended on top of standard anti-inflammatory therapy, due to its role in inhibiting the IL-1 converting enzyme (caspase 1) within the inflammasome as well as the release of additional pro-inflammatory mediators and reactive oxygen species. With regard to treatment of RP refractory to NSAIDs and colchicine, blockade of IL-1 is the most relevant advance achieved in the last decade: the outstanding effect of the short-acting IL-1 receptor antagonist anakinra has been first recognized in the pediatric population, giving a proof of its practical feasibility. Over a more recent time, a growing experience with anakinra deriving from both large and small studies has further confirmed that RP might be regarded as an IL-1-mediated disease. This review aims to provide a contemporary insight into the mechanisms leading to RP as well as into the most recent literature data showing the beneficial approach originating from IL-1 blockade in this intriguing disorder.

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.

Overview of the rarest causes of fever in newborns: handy hints for the neonatologist

Neonatal causes of fever are a major source of concern for clinicians. If fever is combined with organ-specific sterile inflammatory manifestations the suspicion of autoinflammatory disorders should be considered, and the list of such conditions starting in the neonatal period includes chronic infantile neurological cutaneous articular syndrome, mevalonate kinase deficiency, deficiency of the interleukin-1 receptor antagonist, otulipenia, STING-associated vasculopathy with onset in infancy and Blau syndrome. Other causes of noninfectious fever that can rarely occur in newborns are Kawasaki disease, Behçet's disease, and hemophagocytic lymphohistiocytosis. Diagnosis of these exceptionally rare disorders is challenging for neonatologists. An early recognition of these complex diseases might lead to use more specific or rational drugs preventing permanent consequences. This review focuses on the rarest causes of fever occurring in the neonatal age with the aim of portraying many protean clinical pictures associated with fever and reviewing the potential available treatments.

IL-1 Inhibitors in the Treatment of Monogenic Periodic Fever Syndromes: From the Past to the Future Perspectives

Autoinflammatory diseases (AIDs) represent a rare and heterogeneous group of disorders characterized by recurrent episodes of inflammation and a broad range of clinical manifestations. The most common symptoms involve recurrent fevers, musculoskeletal symptoms, and serositis; however, AIDs can also lead to life-threatening complications, such as macrophage activation syndrome (MAS) and systemic AA amyloidosis. Typical monogenic periodic fever syndromes include cryopyrin-associated periodic fever syndrome (CAPS), tumor necrosis factor receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency/hyper IgD syndrome (MKD/HIDS), and familial Mediterranean fever (FMF). However, a number of other clinical entities, such as systemic juvenile idiopathic arthritis (sJIA), adult-onset Still’s disease (AOSD), Kawasaki disease (KD) and idiopathic recurrent pericarditis (IRP), display similar phenotypical and immunological features to AIDs. All these diseases are pathophysiologicaly characterized by dysregulation of the innate immune system and the central pathogenic role is attributed to the IL-1 cytokine family (IL-1α, IL-1β, IL-1Ra, IL-18, IL-36Ra, IL-36α, IL-37, IL-36β, IL-36g, IL-38, and IL-33). Therefore, reasonable therapeutic approaches aim to inhibit these cytokines and their pathways. To date, several anti-IL-1 therapies have evolved. Each drug differs in structure, mechanism of action, efficacy for the treatment of selected diseases, and side effects. Most of the available data regarding the efficacy and safety of IL-1 inhibitors are related to anakinra, canakinumab, and rilonacept. Other promising therapeutics, such as gevokizumab, tadekinig alfa, and tranilast are currently undergoing clinical trials. In this review, we provide sophisticated and up-to-date insight into the therapeutic uses of different IL-1 inhibitors in monogenic periodic fever syndromes.

Children and Adults with PFAPA Syndrome: Similarities and Divergences in a Real-Life Clinical Setting

INTRODUCTION

Analogies or differences of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome in children and adults are barely known. The aim of our study was to compare the overall characteristics of a large cohort of patients, both children and adults, diagnosed with PFAPA syndrome.

METHODS

In the last decade, we identified 120 children and 63 adults with periodically recurring fevers, who fulfilled the criteria for PFAPA diagnosis. The two subcohorts were analyzed according to demographic features, clinical manifestations, laboratory data, and responses to therapies.

RESULTS

The mean age of onset was 2.4 ± 1.5 and 19.7 ± 10.3 years, respectively, in children and adults, while attacks occurred every 3.8 ± 0.8 and every 4.3 ± 2.3 weeks, respectively, in children and adults. A higher prevalence of exudative pharyngitis was observed in children (58.8%), and the majority of children had only two cardinal signs during flares. In adults, there was a higher interpersonal variability of the intercritical periods. Inflammatory markers measured during non-febrile periods were normal in children but altered in the totality of adults during febrile periods. A strong efficacy of corticosteroids in controlling the pediatric syndrome was observed, but response rates to steroids were less brilliant in adults. Colchicine and interleukin-1 inhibitors were used in the management of the steroid-resistant adult syndrome. Conversely, tonsillectomy was performed in a very low number of children, but was effective in 60.7% of adults when treated after 16 years. The mean age of disappearance of PFAPA symptoms has been 6.4 ± 2.4 years in children, while only 27% of adults have shown a complete drug-free symptom regression.

CONCLUSIONS

A linear conformity of the PFAPA syndrome has been observed between pediatric and adult patients. PFAPA symptoms tended to disappear with no sequelae in 94.1% of children, while the disease was still active in almost 3/4 of adults at the time of our assessment.

An update on the pathophysiology of acute and recurrent pericarditis

Pericarditis is an inflammatory disease of the pericardium. Progress has been done in recent years in the understanding of its pathophysiology. In particular, pre-clinical and clinical studies have contributed to increasing our knowledge on the role of interleukin (IL)-1 and NLRP3 (NACHT, leucine- rich repeat, and pyrin domain- containing protein 3) inflammasome. Based on current evidence, pericarditis should be considered as an inflammatory reaction to various stimuli, including chemical/physical, infectious, or ischemic ones, with a viral infection being a common etiology. Interaction of pathogens or irritants with toll-like receptor (TLRs) and stimulation of IL-1 receptor by IL-1α and IL-1β lead to an increased transcription of pro-inflammatory genes, including those needed for NLRP3 inflammasome assembly. This pathway is confirmed indirectly by the beneficial effect of colchicine (an indirect NLRP3 inflammasome inhibitor) and IL-1 blockers in patients with recurrent pericarditis. More recently, a direct evidence of the NLRP3 inflammasome within the inflamed pericardium has been provided as well. It may, however, occur that selfantigens on the surface of mesothelial cells or microbial peptides may stimulate autoreactive T cells along with B cells producing anti-heart antibodies, although less evidence is available on this. Some uncertainties still remain about the role of neutrophils, neutrophil extracellular traps (NETs), and pericardial interstitial cells in recurrent and constrictive pericarditis. Unraveling these aspects might have a direct impact on the development of novel targeted therapies, especially considering the increasing number of drugs targeting NETs.

The off-label use of anakinra in pediatric systemic autoinflammatory diseases

Interleukin 1 (IL-1), a central mediator of innate immunity, is considered a master cytokine of local and systemic inflammation. IL-1 has emerged as pivotal in the pathogenesis of autoinflammatory diseases (AIDs), and blockade of its pathway has become a crucial target for therapy. Anakinra (ANA), a recombinant IL-1β receptor antagonist, was the first anti-IL-1 agent employed in clinical practice. ANA is currently approved for the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, adult-onset Still’s disease, and cryopyrin-associated autoinflammatory syndrome. It has also been successfully used for off-label treatment of various monogenic, polygenic, or undefined etiology systemic AIDs.

This review describes currently available evidence for the off-label use of ANA in pediatric rheumatologic diseases. Specifically, the use of ANA in Kawasaki disease, idiopathic recurrent pericarditis, Behçet disease, monogenic AIDs, undifferentiated AIDs, chronic non-bacterial osteomyelitis, macrophage activation syndrome, and febrile infection-related epilepsy, in terms of its safety and efficacy. In selected pediatric rheumatic disorders, the off-label administration of ANA appears to be effective and safe. In order to control severe and/or relapsing disease, ANA should be considered as a valuable treatment option in children suffering from rare inflammatory diseases. However, currently available data consist of retrospective studies and short case series; thus, randomized controlled trials and larger series with long-term follow up are mandatory to better assess the efficacy and cost effectiveness of ANA in these challenging patients.

Single-Center Overview of Pediatric Monogenic Autoinflammatory Diseases in the Past Decade: A Summary and Beyond

Objective: Monogenic autoinflammatory diseases (AIDs) are inborn disorders caused by innate immunity dysregulation and characterized by robust autoinflammation. We aimed to present the phenotypes and genotypes of Chinese pediatric monogenic AID patients. Methods: A total of 288 pediatric patients clinically suspected to have monogenic AIDs at the Department of Pediatrics of Peking Union Medical College Hospital between November 2008 and May 2019 were genotyped by Sanger sequencing, and/or gene panel sequencing and/or whole exome sequencing. Final definite diagnoses were made when the phenotypes and genotypes were mutually verified. Results: Of the 288 patients, 79 (27.4%) were diagnosed with 18 kinds of monogenic AIDs, including 33 patients with inflammasomopathies, 38 patients with non-inflammasome related conditions, and eight patients with type 1 interferonopathies. Main clinical features were skin disorders (76%), musculoskeletal problems (66%), fever (62%), growth retardation (33%), gastrointestinal tract abnormalities (25%), central nervous system abnormalities (15%), eye disorders (16%), ear problems (9%), and cardiopulmonary disorders (8%). The causative genes were ACP5, ADA2, ADAR1, IFIH1, LPIN2, MEFV, MVK, NLRC4, NLRP3, NLRP12, NOD2, PLCG2, PSMB8, PSTPIP1, TMEM173, TNFAIP3, TNFRSF1A, and TREX1. Conclusions: The present study summarized both clinical and genetic characteristics of 18 kinds of monogenic AIDs found in the largest pediatric AID center over the past decade, with fever, skin problems, and musculoskeletal system disorders being the most prevalent clinical features. Many of the mutations were newly discovered. This is by far the first and largest monogenic AID report in Chinese pediatric population and also a catalog of the phenotypic and genotypic features among these patients.

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.

Clinical Features at Onset and Genetic Characterization of Pediatric and Adult Patients with TNF-α Receptor-Associated Periodic Syndrome (TRAPS): A Series of 80 Cases from the AIDA Network

This study explores demographic, clinical, and therapeutic features of tumor necrosis factor receptor-associated periodic syndrome (TRAPS) in a cohort of 80 patients recruited from 19 Italian referral Centers. Patients' data were collected retrospectively and then analyzed according to age groups (disease onset before or after 16 years) and genotype (high penetrance (HP) and low penetrance (LP) TNFRSF1A gene variants). Pediatric- and adult-onset were reported, respectively, in 44 and 36 patients; HP and LP variants were found, respectively, in 32 and 44 cases. A positive family history for recurrent fever was reported more frequently in the pediatric group than in the adult group (p < 0.05). With reference to clinical features during attacks, pericarditis and myalgia were reported more frequently in the context of adult-onset disease than in the pediatric age (with p < 0.01 and p < 0.05, respectively), while abdominal pain was present in 84% of children and in 25% of adults (p < 0.01). Abdominal pain was significantly associated also to the presence of HP mutations (p < 0.01), while oral aphthosis was more frequently found in the LP variant group (p < 0.05). Systemic amyloidosis occurred in 25% of subjects carrying HP variants. As concerns laboratory features, HP mutations were significantly associated to higher ESR values (p < 0.01) and to the persistence of steadily elevated inflammatory markers during asymptomatic periods (p < 0.05). The presence of mutations involving a cysteine residue, abdominal pain, and lymphadenopathy during flares significantly correlated with the risk of developing amyloidosis and renal impairment. Conversely, the administration of colchicine negatively correlated to the development of pathologic proteinuria (p < 0.05). Both NSAIDs and colchicine were used as monotherapy more frequently in the LP group compared to the HP group (p < 0.01). Biologic agents were prescribed to 49 (61%) patients; R92Q subjects were more frequently on NSAIDs monotherapy than other patients (p < 0.01); nevertheless, they required biologic therapy in 53.1% of cases. At disease onset, the latest classification criteria for TRAPS were fulfilled by 64/80 (80%) patients (clinical plus genetic items) and 46/80 (57.5%) patients (clinical items only). No statistically significant differences were found in the sensitivity of the classification criteria according to age at onset and according to genotype (p < 0.05). This study describes one of the widest cohorts of TRAPS patients in the literature, suggesting that the clinical expression of this syndrome is more influenced by the penetrance of the mutation rather than by the age at onset itself. Given the high phenotypic heterogeneity of the disease, a definite diagnosis should rely on both accurate working clinical assessment and complementary genotype.

Phenotype variability of autoinflammatory disorders in the pediatric patient: A pictorial overview

Disruption of innate immunity leading to systemic inflammation and multi-organ dysfunction is the basilar footprint of autoinflammatory disorders (AIDs), ranging from rare hereditary monogenic diseases to a large number of common chronic inflammatory conditions in which there is a simultaneous participation of multiple genetic components and environmental factors, sometimes combined with autoimmune phenomena and immunodeficiency. Whatever their molecular mechanism, hereditary AIDs are caused by mutations in regulatory molecules or sensors proteins leading to dysregulated production of proinflammatory cytokines or cytokine-inducing transcription factors, fever, elevation of acute phase reactants, and a portfolio of manifold inflammatory signs which might occur in a stereotyped manner, mostly with overactivity or misactivation of different inflammasomes. Symptoms might overlap in the pediatric patient, obscuring the final diagnosis of AIDs and delaying the most appropriate treatment. Actually, the fast-paced evolution of scientific knowledge has led to recognize or reclassify an overgrowing number of multifactorial diseases, which share the basic pathogenetic mechanisms with AIDs. The wide framework of classic hereditary periodic fevers, AIDs with prominent skin involvement, disorders of the ubiquitin-proteasome system, defects of actin cytoskeleton dynamics, and also idiopathic nonhereditary febrile syndromes occurring in children is herein presented. Interleukin-1 dependence of these diseases or involvement of other predominating molecules is also discussed.

Role of Colchicine Treatment in Tumor Necrosis Factor Receptor Associated Periodic Syndrome (TRAPS): Real-Life Data from the AIDA Network

Objective

To analyze the potential role of colchicine monotherapy in patients with tumor necrosis factor receptor associated periodic syndrome (TRAPS) in terms of control of clinical and laboratory manifestations.

Methods

Patients with TRAPS treated with colchicine monotherapy were retrospectively enrolled; demographic, clinical and therapeutic data were collected and statistically analysed after having clustered patients according to different times at disease onset, penetrance of mutations, dosage of colchicine, and different disease manifestations.

Results

24 patients (14 males; 15 with pediatric disease onset) treated with colchicine monotherapy were enrolled. Colchicine resulted in a complete response in 3 (12.5%) cases, partial response in 14 (58.3%) patients, and lack of response in 7 (29.2%) patients. There were not significant differences in colchicine response between pediatric and adult disease onset (p = 0.42), between low- and high-penetrance mutations (p = 0.62), and according to different dosages (p = 0.66). No significant differences were identified in the frequency of specific disease manifestations between patients experiencing any response to colchicine and patients with lack of response.

Conclusions

Colchicine monotherapy is useful in a low percentage of TRAPS patients; nevertheless, it could be attempted in patients with milder phenotypes and at a lower risk of developing reactive amyloidosis.

Hints for Genetic and Clinical Differentiation of Adult-Onset Monogenic Autoinflammatory Diseases

Monogenic autoinflammatory diseases (mAIDs) are inherited errors of innate immunity characterized by systemic inflammation recurring with variable frequency and involving the skin, serosal membranes, synovial membranes, joints, the gastrointestinal tube, and/or the central nervous system, with reactive amyloidosis as a potential severe long-term consequence. Although individually uncommon, all mAIDs set up an emerging chapter of internal medicine: recent findings have modified our knowledge regarding mAID pathophysiology and clarified that protean inflammatory symptoms can be variably associated with periodic fevers, depicting multiple specific conditions which usually start in childhood, such as familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, cryopyrin-associated periodic syndrome, and mevalonate kinase deficiency. There are no evidence-based studies to establish which potential genotype analysis is the most appropriate in adult patients with clinical phenotypes suggestive of mAIDs. This review discusses genetic and clinical hints for an ideal diagnostic approach to mAIDs in adult patients, as their early identification is essential to prompt effective treatment and improve quality of life, and also highlights the most recent developments in the diagnostic work-up for the most frequent hereditary periodic febrile syndromes worldwide.

Patients with tumour necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) are hypersensitive to Toll-like receptor 9 stimulation

Tumour necrosis factor receptor-associated periodic syndrome (TRAPS) is a hereditary autoinflammatory disorder characterized by recurrent episodes of fever and inflammation. It is associated with autosomal dominant mutations in TNFRSF1A, which encodes tumour necrosis factor receptor 1 (TNF-R1). Our aim was to understand the influence of TRAPS mutations on the response to stimulation of the pattern recognition Toll-like receptor (TLR)-9. Peripheral blood mononuclear cells (PBMCs) and serum were isolated from TRAPS patients and healthy controls: serum levels of 15 proinflammatory cytokines were measured to assess the initial inflammatory status. Interleukin (IL)-1β, IL-6, IL-8, IL-17, IL-22, tumour necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), interferon (IFN)-γ, monocyte chemoattractant protein 1 (MCP-1) and transforming growth factor (TGF)-β were significantly elevated in TRAPS patients' sera, consistent with constitutive inflammation. Stimulation of PBMCs with TLR-9 ligand (ODN2006) triggered significantly greater up-regulation of proinflammatory signalling intermediates [TNF receptor-associated factor (TRAF 3), IL-1 receptor-associated kinase-like 2 (IRAK2), Toll interacting protein (TOLLIP), TRAF6, phosphorylated transforming growth factor-β-activated kinase 1 (pTAK), transforming growth factor-β-activated kinase-binding protein 2 (TAB2), phosphorylated TAK 2 (pTAB2), IFN-regulatory factor 7 (IRF7), receptor interacting protein (RIP), nuclear factor kappa B (NF-κB) p65, phosphorylated NF-κB p65 (pNF-κB p65) and mitogen-activated protein kinase kinase (MEK1/2)] in TRAPS patients' PBMCs. This up-regulation of proinflammatory signalling intermediates and raised serum cytokines occurred despite concurrent anakinra treatment and no overt clinical symptoms at time of sampling. These novel findings further demonstrate the wide-ranging nature of the dysregulation of innate immune responses underlying the pathology of TRAPS and highlights the need for novel pathway-specific therapeutic treatments for this disease.

Naturally occurring and synthetic constitutive-active cytokine receptors in disease and therapy

Cytokines control immune related events and are critically involved in a plethora of patho-physiological processes including autoimmunity and cancer development. Mutations which cause ligand-independent, constitutive activation of cytokine receptors are quite frequently found in diseases. Many constitutive-active cytokine receptor variants have been directly connected to disease development and mechanistically analyzed. Nature's solutions to generate constitutive cytokine receptors has been recently adopted by synthetic cytokine receptor biology, with the goal to optimize immune therapeutics. Here, CAR T cell immmunotherapy represents the first example to combine synthetic biology with genetic engineering during therapy. Hence, constitutive-active cytokine receptors are therapeutic targets, but also emerging tools to improve or modulate immunotherapeutic strategies. This review gives a comprehensive insight into the field of naturally occurring and synthetic constitutive-active cytokine receptors.

Familial Mediterranean Fever: Assessing the Overall Clinical Impact and Formulating Treatment Plans

Recurrent self-limited attacks of fever and short-lived inflammation in the serosal membranes, joints, and skin are the leading features of familial Mediterranean fever (FMF), the most common autoinflammatory disorder in the world, transmitted as autosomal recessive trait caused by MEFV gene mutations. Their consequence is an abnormal function of pyrin, a natural repressor of inflammation, apoptosis, and release of cytokines. FMF-related mutant pyrins are hypophosphorylated following RhoA GTPases' impaired activity and show a propensity to relapsing uncontrolled systemic inflammation with inappropriate response to inflammatory stimuli and leukocyte spread to serosal membranes, joints or skin. Typical FMF phenotype 1 consists of brief episodes of inflammation and serositis, synovitis, and/or erysipelas-like eruption, whereas phenotype 2 is defined by reactive amyloid-associated (AA) amyloidosis, which is the most ominous complication of FMF, in otherwise asymptomatic individuals. Furthermore, FMF phenotype 3 is referred to the presence of two MEFV mutations with neither clinical signs of FMF nor AA amyloidosis. The influence of epigenetic and/or environmental factors can contribute to the variable penetrance and phenotypic heterogeneity of FMF. Colchicine, a tricyclic alkaloid with anti-microtubule and anti-inflammatory properties, is the bedrock of FMF management: daily administration of colchicine prevents the recurrence of FMF attacks and the development of secondary AA amyloidosis. Many recent studies have also shown that anti-interleukin-1 treatment is the best therapeutic option for FMF patients nonresponsive or intolerant to colchicine. This review aims to catch readers' attention to the clinical diversity of phenotypes, differential diagnosis, and management of patients with FMF.

Treating TNF Receptor Associated Periodic Fever Syndrome in End-Stage Renal Failure

Tumor necrosis factor receptor associated periodic syndrome (TRAPS) is a rare monogenic autoinflammatory disease. Its most severe manifestation is secondary amyloidosis. A 44-year-old male presented with nephrotic syndrome. Kidney biopsy was conclusive for secondary amyloidosis. The patient and his children had a history of recurrent febrile periods since infancy. All subjects were positive for a heterozygous variant of the TNFRSF1A gene, confirming TRAPS diagnosis. The patient progressed to end-stage renal failure and developed recurrent pericarditis episodes. He was started on anakinra while on hemodialysis with marked reduction of his serum amyloid A protein (SAA) levels. Meanwhile he received a cadaveric renal transplant and maintains anakinra treatment. Despite renal failure being the most feared complication of AA amyloidosis caused by TRAPS, little data is available about safety of anti-IL-1 treatment in patients with severe kidney failure. The authors report this case of a patient on dialysis treated with anakinra in which no complications were registered. Though amyloidosis is established, the authors believe containing its progression and reducing inflammatory activity can improve patient prognosis and reduce recurrence of amyloidosis in kidney transplant, as has been demonstrated in transplanted patients due to familial Mediterranean fever amyloidosis.

Unveiling the Efficacy, Safety, and Tolerability of Anti-Interleukin-1 Treatment in Monogenic and Multifactorial Autoinflammatory Diseases

Autoinflammatory diseases (AIDs) are heterogeneous disorders characterized by dysregulation in the inflammasome, a large intracellular multiprotein platform, leading to overproduction of interleukin-1(IL-1)β that plays a predominant pathogenic role in such diseases. Appropriate treatment is crucial, also considering that AIDs may persist into adulthood with negative consequences on patients' quality of life. IL-1β blockade results in a sustained reduction of disease severity in most AIDs. A growing experience with the human IL-1 receptor antagonist, Anakinra (ANA), and the monoclonal anti IL-1β antibody, Canakinumab (CANA), has also been engendered, highlighting their efficacy upon protean clinical manifestations of AIDs. Safety and tolerability have been confirmed by several clinical trials and observational studies on both large and small cohorts of AID patients. The same treatment has been proposed in refractory Kawasaki disease, an acute inflammatory vasculitis occurring in children before 5 years, which has been postulated to be autoinflammatory for its phenotypical and immunological similarity with systemic juvenile idiopathic arthritis. Nevertheless, minor concerns about IL-1 antagonists have been raised regarding their employment in children, and the development of novel pharmacological formulations is aimed at minimizing side effects that may affect adherence to treatment. The present review summarizes current findings on the efficacy, safety, and tolerability of ANA and CANA for treatment of AIDs and Kawasaki vasculitis with a specific focus on the pediatric setting.

The TNF Family of Ligands and Receptors: Communication Modules in the Immune System and Beyond

The tumor necrosis factor (TNF) and TNF receptor (TNFR) superfamilies (TNFSF/TNFRSF) include 19 ligands and 29 receptors that play important roles in the modulation of cellular functions. The communication pathways mediated by TNFSF/TNFRSF are essential for numerous developmental, homeostatic, and stimulus-responsive processes in vivo. TNFSF/TNFRSF members regulate cellular differentiation, survival, and programmed death, but their most critical functions pertain to the immune system. Both innate and adaptive immune cells are controlled by TNFSF/TNFRSF members in a manner that is crucial for the coordination of various mechanisms driving either co-stimulation or co-inhibition of the immune response. Dysregulation of these same signaling pathways has been implicated in inflammatory and autoimmune diseases, highlighting the importance of their tight regulation. Investigation of the control of TNFSF/TNFRSF activities has led to the development of therapeutics with the potential to reduce chronic inflammation or promote anti-tumor immunity. The study of TNFSF/TNFRSF proteins has exploded over the last 30 yr, but there remains a need to better understand the fundamental mechanisms underlying the molecular pathways they mediate to design more effective anti-inflammatory and anti-cancer therapies.

The Broad-Ranging Panorama of Systemic Autoinflammatory Disorders with Specific Focus on Acute Painful Symptoms and Hematologic Manifestations in Children

Systemic autoinflammatory disorders (SAIDs) are inherited defects of innate immunity characterized by recurrent sterile inflammatory attacks involving skin, joints, serosal membranes, gastrointestinal tube, and other tissues, which recur with variable rhythmicity and display reactive amyloidosis as a potential long-term complication. Dysregulated inflammasome activity leading to overproduction of many proinflammatory cytokines, such as interleukin-1 (IL-1), and delayed shutdown of inflammation are considered crucial pathogenic keys in the vast majority of SAIDs. Progress of cellular biology has partially clarified the mechanisms behind monogenic SAIDs, such as familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, cryopyrin-associated periodic syndrome, mevalonate kinase deficiency, hereditary pyogenic diseases, idiopathic granulomatous diseases and defects of the ubiquitin-proteasome pathway. Whereas, little is clarified for the polygenic SAIDs, such as periodic fever, aphthous stomatitis, pharyngitis, and cervical adenopathy (PFAPA) syndrome. The puzzle of symptomatic febrile attacks recurring over time in children requires evaluating the mixture of clinical data, inflammatory parameters in different disease phases, the therapeutic efficacy of specific drugs such as colchicine, corticosteroids or IL-1 antagonists, and genotype analysis in selected cases. The long-term history of periodic fevers should also need to rule out chronic infections and malignancies. This review is conceived as a practical template for proper classification of children with recurring fevers and includes tips useful for the diagnostic approach to SAIDs, focusing on the specific acute painful symptoms and hematologic manifestations encountered in childhood.

A Comprehensive Overview of the Hereditary Periodic Fever Syndromes

Innate immunity is a critical partner in the regulation of inflammation and some mutations in genes implied in innate immunity pathways can cause genetic disorders characterized by seemingly unprovoked self-limited inflammatory attacks. These rare conditions are collectively named "hereditary periodic fever syndromes" (HPFS), and protean pathogenetic mechanisms combined with several clinical phenotypes characterize at least four distinct conditions: (1) familial Mediterranean fever, which is the prototype and the most widely recognized among HPFS, inherited as an autosomal recessive disorder showing recurrent dysregulated inflammatory processes, caused by an abnormal interaction between cytoskeleton and inflammasome, a key-signaling platform that releases interleukin-1β (IL-1β); (2) the group of cryopyrin-associated periodic syndrome, which upsets directly the production of IL-1β, with a dominant pattern of inheritance; (3) tumor necrosis factor receptor-associated periodic syndrome, which is an autosomal dominant disorder subverting the functions and traffic of a cell membrane protein; and (4) mevalonate kinase deficiency, which is an autosomal recessive metabolic disorder halting the biosynthesis of cholesterol. MEFV, NLRP3, TNFRSF1A, and MVK are respectively the four causing genes of these conditions, all resulting in excessive IL-1β signaling, though the encoded proteins act at different levels in cytoskeletal filament organization, apoptosis, and activation of the IL-1β-structured inflammasome. The differential diagnosis of HPFS can be challenging, as there are no universally accepted diagnostic algorithms, and near half of patients may have a specific disease without any genetic pathogenetic variant identified. Herein, we outline the most relevant aspects of HPFS at the crossroads between clinical medicine and immunology and all the most recent advances in their treatment, as the increasing use of IL-1 antagonists has achieved unexpected clinical results in a large number of patients.

New mosaic tiles in childhood hereditary autoinflammatory disorders

The protean clinical phenotypes of hereditary autoinflammatory disorders (HAID) are caused by abnormal activation of innate immunity and consist of seemingly unprovoked inflammatory flares localized to multiple organs, such as the skin, joints, serosal membranes, gut, and central nervous system. Different mutations in genes implied in activation of the interleukin-1 (IL-1)-structured inflammasome, cytoskeletal signaling and apoptosis contribute to the pathogenesis of different HAID, which mostly start in childhood with self-limited flares unrelated to infectious agents, autoantibody production or autoreactive cells. Though IL-1 remains pivotal in many inflammasome-mediated diseases, other cytokinopathies involving IL-18, nuclear factorκ-B, interferons, and tumor necrosis factor have provided new horizons in the definition of HAID of children: the list of HAID has expanded as a consequence of a better understanding of their pathogenetic molecular mechanisms and also application of new genetic technologies. However, diagnosis of most HAID is clinical and focused on several evidence-based criteria sets: their discrimination remains challenging for unexperienced pediatricians as there are no universally accepted algorithms, and a still relevant number of patients may linger without any clarifying genetic analysis, whose interpretation combined with processing of treatment options should be discussed on a multidisciplinary basis.

The diagnostic evaluation of patients with a suspected hereditary periodic fever syndrome: experience from a referral center in Italy

The study aims are to describe the activity of our Unit on the diagnostics of monogenic autoinflammatory diseases (AIDs), and to apply the clinical classification criteria for periodic fevers from the Eurofever Registry to our cohort of patients, thus evaluating their usefulness in the real life. We retrospectively analyzed data from patients referring to our Center for recurrent fever attacks, and undergoing genetic analysis between April 2014 and July 2016, and we applied the classification criteria to both genetically positive and -negative patients. We visited 195 patients (101 females, 94 males); 126 (64.6%) were adults and 192 (98.5%) Caucasians; 12.3% carried mutations and 12.7% of adults were genetically positive. No statistically significant differences were identified in the frequency of genetic diagnosis between adults and children (p = 0.82) as well as in the frequency of genetic diagnosis, based on the number of genes evaluated (p = 0.57). When we applied the Eurofever criteria, 126/195 (64.6%) patients were classified for at least one among the four main monogenic AIDs; 22 (11.3%) patients fulfilled criteria for 2 diseases and 4 (2.1%) for 3 diseases. Among patients carrying mutations, 12/24 (50%) correctly fulfilled the score, 3/24 (12.5%) fulfilled criteria differently from their genetic diagnosis; 9/22 (40.9%) recieved no classification. An expanded genetic testing does not seem useful, while a correct interpretation of patients' clinical picture may allow performing specific genetic testing. The classification criteria from the Eurofever Registry have shown to be a beneficial tool in the evaluation of patients with a suspected monogenic AID.

Efficacy and safety of anakinra in tumor necrosis factor receptor-associated periodic syndrome (TRAPS) complicated by severe renal failure: a report after long-term follow-up and review of the literature

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS), caused by mutations in the TNFRSF1A gene, is the most frequent autosomal dominant autonflammatory disease displaying a relevant risk of reactive AA amyloidosis, if left untreated. Our report deals with one adult with TRAPS complicated by amyloidosis-related renal failure, treated with the recombinant human interleukin-1 receptor antagonist anakinra at a higher than conventional dosage. This treatment did not present any adverse event and led remarkably to the disappearance of all TRAPS-related manifestations and prompt decrease of laboratory abnormalities, including proteinuria. A review of the medical literature has been also considered to evaluate efficacy and safety of interleukin-1 inhibition in patients with TRAPS.

A systematic approach to autoinflammatory syndromes: a spelling booklet for the beginner

Hallmark of autoinflammatory syndromes (AIS) is the periodic recurrence of 'sterile' inflammatory attacks characterized by fever and organ- or tissue-specific inflammation. Basic research projects over the last two decades have boosted our understanding of pathological pathways, mainly involving interleukin (IL)-1 biosynthesis, and also revealed that their dysregulation results from genetically-heterogeneous inborn errors of innate immunity and leads to multiple inflammatory phenotypes. Starting from the evidence of poor response to IL-1 inhibitors of some patients with multi-organ inflammation, further research studies have disclosed a crucial role for nuclear factor (NF)-κB and type I interferon (IFN) in specific AIS. Presently, new genetically-defined AIS have been identified, following the in-depth analysis of molecular pathways which involve either constitutive NF-κB activation or IFN signaling. Areas covered: This review is intended as a spelling booklet to help clinicians approaching patients with AIS in a simple way, using the component of the innate immunity they mainly affect. AIS have been split into 4 groups: IL-1-mediated disorders, NF-κB-mediated disorders, IFN-mediated disorders, and syndromes with still unraveled pathogenetic mechanisms or without any dominating cytokine involved. This classification has mere scholastic purposes and does not reflect the intimate complexity of each disorder discussed herein. Expert commentary: The understanding of dysregulated molecular pathways driving specific phenotypes in most AIS has prompted numerous projects to discover therapies targeting directly cytokine-mediated manifestations in such problematic patients, hopefully aimed to decrease or cancel inflammation and lead to a drastic change in patients' lives. The future has only begun.

Novel mutation identified in severe early-onset tumor necrosis factor receptor-associated periodic syndrome: a case report

Background

Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS) is the second most common heritable autoinflammatory disease, typically presenting in pre-school aged children with fever episodes lasting 1–3 weeks. Systemic symptoms can include rash, myalgia, ocular inflammation, and serositis.

Case presentation

Here we report an unusual presentation of TRAPS in a 7 month old girl who presented with only persistent fever. She was initially diagnosed with incomplete Kawasaki Disease and received IVIG and infliximab; however, her fevers quickly recurred. Subsequent testing revealed a urinary tract infection, but she did not improve despite appropriate therapy. As fever continued, she developed significant abdominal distension with imaging concerning for appendicitis, followed by hyperthermia and hemodynamic instability. Given her protracted clinical course and maternal history of a poorly defined inflammatory condition, an autoinflammatory disease was considered. Therapy with anakinra was initiated, resulting in rapid resolution of fever and normalization of inflammatory markers. She was found to have a previously unreported mutation, Thr90Pro, in the TNFRSF1A gene associated with TRAPS. This novel mutation was also confirmed in the patient’s mother and maternal uncle.

Conclusions

This report reviews a severe case of TRAPS in infancy associated with a novel mutation, Thr90Pro, in the TNFRSF1A gene, and emphasizes that autoinflammatory disease should be considered in the differential of infants with fever of unknown origin.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0856-2) contains supplementary material, which is available to authorized users.

Clinical dose effect and functional consequences of R92Q in two families presenting with a TRAPS/PFAPA-like phenotype

Background

TNF receptor‐associated syndrome (TRAPS) is a dominantly inherited autoinflammatory condition caused by mutations in the TNFRSF1A gene. The mechanism underlying the variable expressivity of the common variant R92Q (rs4149584; c.362G>A; p.Arg121Gln) is unclear and is of critical importance for patient care and genetic counseling. This study evaluated the impact of the number of R92Q mutations in two unique unrelated families.

Methods

Two patients with undefined but clear autoinflammatory symptoms were referred for genetic diagnosis. Blood samples were collected from the available family members to screen autoinflammatory genes and assess key steps of the TNFR1‐mediated signaling pathway using flow cytometry and ex vivo culture.

Results

R92Q homozygosity was demonstrated for the two probands. In family 1, the segregation analysis revealed TRAPS‐like symptoms in all carriers, with a more severe presentation in the proband, whereas in family 2, the heterozygous parents were totally asymptomatic, suggesting recessive transmission. Functional studies revealed a nonclassical pathogenesis of TRAPS in the two probands and suggested a compensatory mechanism without clear dose effect.

Conclusion

We observed for the first time a possible clinical dose effect of R92Q. This work highlights the importance of familial studies to reconcile the contradictory reports published on the pathogenicity of this variant.

Lung Involvement in Children with Hereditary Autoinflammatory Disorders

Short-lived systemic inflammatory reactions arising from disrupted rules in the innate immune system are the operating platforms of hereditary autoinflammatory disorders (HAIDs). Multiple organs may be involved and aseptic inflammation leading to disease-specific phenotypes defines most HAIDs. Lungs are infrequently involved in children with HAIDs: the most common pulmonary manifestation is pleuritis in familial Mediterranean fever (FMF) and tumor necrosis factor receptor-associated periodic syndrome (TRAPS), respectively caused by mutations in the MEFV and TNFRSF1A genes, while interstitial lung disease can be observed in STING-associated vasculopathy with onset in infancy (SAVI), caused by mutations in the TMEM173 gene. The specific pleuropulmonary diseases may range from sub-clinical abnormalities during inflammatory flares of FMF and TRAPS to a severe life-threatening disorder in children with SAVI.

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.

Targeted genomic analysis reveals widespread autoimmune disease association with regulatory variants in the TNF superfamily cytokine signalling network

BACKGROUND

Tumour necrosis factor (TNF) superfamily cytokines and their receptors regulate diverse immune system functions through a common set of signalling pathways. Genetic variants in and expression of individual TNF superfamily cytokines, receptors and signalling proteins have been associated with autoimmune and inflammatory diseases, but their interconnected biology has been largely unexplored.

METHODS

We took a hypothesis-driven approach using available genome-wide datasets to identify genetic variants regulating gene expression in the TNF superfamily cytokine signalling network and the association of these variants with autoimmune and autoinflammatory disease. Using paired gene expression and genetic data, we identified genetic variants associated with gene expression, expression quantitative trait loci (eQTLs), in four peripheral blood cell subsets. We then examined whether eQTLs were dependent on gene expression level or the presence of active enhancer chromatin marks. Using these eQTLs as genetic markers of the TNF superfamily signalling network, we performed targeted gene set association analysis in eight autoimmune and autoinflammatory disease genome-wide association studies.

RESULTS

Comparison of TNF superfamily network gene expression and regulatory variants across four leucocyte subsets revealed patterns that differed between cell types. eQTLs for genes in this network were not dependent on absolute gene expression levels and were not enriched for chromatin marks of active enhancers. By examining autoimmune disease risk variants among our eQTLs, we found that risk alleles can be associated with either increased or decreased expression of co-stimulatory TNF superfamily cytokines, receptors or downstream signalling molecules. Gene set disease association analysis revealed that eQTLs for genes in the TNF superfamily pathway were associated with six of the eight autoimmune and autoinflammatory diseases examined, demonstrating associations beyond single genome-wide significant hits.

CONCLUSIONS

This systematic analysis of the influence of regulatory genetic variants in the TNF superfamily network reveals widespread and diverse roles for these cytokines in susceptibility to a number of immune-mediated diseases.

Lights and shadows in autoinflammatory syndromes from the childhood and adulthood perspective

In a high percentage of cases, the monogenic autoinflammatory syndromes (AIS), caused by subversion in the inflammasome homeostasis leading to cytokine oversecretion and characterized by multiple inflammatory pictures, start in childhood. However, the description of tardive manifestations, veiled phenotypes, and atypical clinical signs beginning in adulthood has been more and more reported in recent times, requiring that many specialists become confident with concepts, details, and management strategies of AIS. Differences between child- and adult-onset syndromes raise the question of whether pathogenic mechanisms might differ when the timetable of AIS onset diverges, but show that carefulness is needed to establish a straightforward diagnosis.

Basic Characteristics of Adults with Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenopathy Syndrome in Comparison with the Typical Pediatric Expression of Disease

Autoinflammatory diseases are caused by inflammasome dysregulation leading to overproduction of proinflammatory cytokines and a pathological delay in the inflammation switching off. The progress of cellular biology has partially clarified pathogenic mechanisms behind monogenic autoinflammatory diseases, whereas little is known about the polygenic ones. Although the genetic susceptibility of periodic fever, aphthous stomatitis, pharyngitis, and adenopathy (PFAPA) syndrome is still obscure, the presence of overlapping symptoms with monogenic periodic fevers, the recurrence in family members, the important role played by dysregulated interleukin- (IL-) 1β secretion during flares, the overexpression of inflammasome-associated genes during attacks, and, last but not least, the therapeutic efficacy of IL-1β blockade strongly indicate a potential genetic involvement in its pathogenesis, probably linked with environmental factors. PFAPA syndrome has a typical inception in the pediatric age, but a delayed onset during adulthood has been described as well. Treatments required as well as effectiveness of tonsillectomy remain controversial, even if the disease seems to have a self-limited course mostly in children. The purpose of this review is to provide an overview of this complex polygenic/multifactorial autoinflammatory disorder in which the innate immune system undoubtedly plays a basic role.

The protean ocular involvement in monogenic autoinflammatory diseases: state of the art

Ocular involvement is frequent in the monogenic autoinflammatory disorders and generally occurs as spontaneously recurring inflammatory events at different ocular sites caused by the aberrant release of proinflammatory cytokines, mainly IL-1β. Over the past decade, we witnessed a significant growth of eye abnormalities associated with idiopathic granulomatous disorders, familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, mevalonate kinase deficiency, and cryopyrin-associated periodic syndrome. The pathogenetic mechanisms of these disorders have shown the evidence of disrupted cytokine signaling, but the explanation for the heterogeneous ocular involvement remains to be elucidated. We herein review the monogenic autoinflammatory disorders affecting the eye, describing their main clinical features with specific regard to the ocular involvement, which can lead to decreased visual acuity and even blindness, if the primary disorder is undetected or left untreated.

Interleukin-1 as a common denominator from autoinflammatory to autoimmune disorders: premises, perils, and perspectives

A complex web of dynamic relationships between innate and adaptive immunity is now evident for many autoinflammatory and autoimmune disorders, the first deriving from abnormal activation of innate immune system without any conventional danger triggers and the latter from self-/non-self-discrimination loss of tolerance, and systemic inflammation. Due to clinical and pathophysiologic similarities giving a crucial role to the multifunctional cytokine interleukin-1, the concept of autoinflammation has been expanded to include nonhereditary collagen-like diseases, idiopathic inflammatory diseases, and metabolic diseases. As more patients are reported to have clinical features of autoinflammation and autoimmunity, the boundary between these two pathologic ends is becoming blurred. An overview of monogenic autoinflammatory disorders, PFAPA syndrome, rheumatoid arthritis, type 2 diabetes mellitus, uveitis, pericarditis, Behçet's disease, gout, Sjögren's syndrome, interstitial lung diseases, and Still's disease is presented to highlight the fundamental points that interleukin-1 displays in the cryptic interplay between innate and adaptive immune systems.