Systemic Autoinflammatory Diseases: A Growing Family of Disorders of Overlapping Immune Dysfunction

Anti-tumor necrosis factor therapy in the treatment of systemic autoinflammatory diseases: the responses of innate immune cells

Systemic autoinflammatory diseases are rare conditions resulting from dysregulation of the innate immune system, culminating in repetitive bouts of systemic inflammation without the presence of external or self-antigens. Most systemic autoinflammatory diseases are associated with mutations in genes affecting the innate immune response. Tumor necrosis factor is a central player in the pathogenesis of numerous chronic inflammatory disorders, and anti-tumor necrosis factor therapy is widely used in the clinical management of systemic autoinflammatory diseases. Tumor necrosis factor inhibitors block the interaction of tumor necrosis factor with its 2 receptors, tumor necrosis factor receptor 1 and tumor necrosis factor receptor 2. These inhibitors primarily target soluble tumor necrosis factor, which mainly binds to tumor necrosis factor receptor 1, exerting anti-inflammatory effects. Interestingly, tumor necrosis factor inhibitors also affect transmembrane tumor necrosis factor, which engages tumor necrosis factor receptor 2 to initiate reverse signaling. This reverse signaling can activate innate immune cells, prevent apoptosis, or paradoxically inhibit the production of pro-inflammatory cytokines. Tumor necrosis factor inhibitors also promote the release of soluble tumor necrosis factor receptor 2, which neutralizes circulating tumor necrosis factor. Some agents targeting tumor necrosis factor receptor 2 can even act as agonists, triggering reverse signaling by binding to transmembrane tumor necrosis factor. While effective, prolonged use of tumor necrosis factor inhibitors may cause significant side effects due to the widespread expression and pleiotropic functions of tumor necrosis factor receptors. A more thorough understanding of the mechanisms underlying the action of tumor necrosis factor inhibitors is required to develop a more effective and safer treatment for systemic autoinflammatory diseases. This article reviews current studies on the role of the innate immune system in systemic autoinflammatory disease pathogenesis, the impact of anti-tumor necrosis factor therapy on innate immune cells, and perspectives on developing improved agents targeting tumor necrosis factor or its receptors.

Mental Ill-Health in young people with systemic autoinflammatory disease - a scoping review

Systemic autoinflammatory disorders (SAID), immune dysregulation disorders with onset frequently occurring in youth, are defined by unprovoked inflammation. Research suggest inflammation is associated with the pathogenesis of mental ill-health. Separately, research has identified that mental ill-health is prevalent in people with immune dysregulation disorders compared to healthy controls or those with other chronic diseases, and the psychosocial impacts of these diseases on quality of life can be debilitating. This review aimed to broadly identify the extent and nature of research involving young people with SAIDs and mental ill-health. A scoping review was conducted across 6 databases of peer-reviewed articles referring to SAIDs and mental ill-health in young people. Of 727 studies, 41 met the inclusion criteria. Thirty-seven were observational studies, including 18 case studies or series. Four studies were treatment trials. Fourteen observational studies investigated the prevalence of mental ill-health in a SAID population with large sample sizes. Most studies were conducted in Türkiye, involving Behçet's syndrome or familial Mediterranean fever and anxiety, depression, and psychosis were strongly represented. Findings suggest an association between mental ill-health and SAID activity in young people. Anxiety and depression were associated with some specific SAIDs duration, symptom severity, SAID flare recency and frequency, and SAID treatment effects. Co-occurrence and resolution of SAID flares and mental ill-health with treatment were frequent themes in case studies of some SAIDs. Further research is required on the prevalence and risk of developing mental ill-health among young people with SAIDs, along with associations between mental ill-health, other SAIDs and disease activity, other participant variables, and appropriate management of mental ill-health in this population.

Overview of Systemic Autoinflammatory Diseases

Systemic autoinflammatory diseases (SAID) are a growing family of disorders of the innate immune system. Over the years, there have been changes in the definition, classification and nomenclature of SAID as new syndromes and pathophysiologic mechanisms continue to be described. Recognizing the clinical manifestations of SAID is important for their early diagnosis and management. The field continues to advance with potential new therapies underway.

Update on autoinflammatory diseases

PURPOSE OF REVIEW

Although the concept of systemic autoinflammatory diseases (SAIDs) is still very young, our knowledge about them is exponentially growing. In the current review, we aim to discuss novel SAIDs and autoinflammatory pathways discovered in the last couple of years.

RECENT FINDINGS

Advances in immunology and genetics have led to the discovery of new pathways involved in autoinflammation, as well as several new SAIDs, including retinal dystrophy, optic nerve edema, splenomegaly, anhidrosis, and migraine headache (ROSAH syndrome), vacuoles, E1 enzyme, X-linked autoinflammatory somatic (VEXAS) syndrome, TBK1 deficiency, NEMO deleted exon 5 autoinflammatory syndrome (NDAS), and disabling pansclerotic morphea. Progress in immunobiology and genetics has also brought forth novel treatments for SAIDs. Personalized medicine has made significant progress in areas such as cytokine-targeted therapies and gene therapies. However, much work remains, especially in measuring and improving the quality of life in patients with SAIDs.

SUMMARY

In the current review, we discuss the novelties in the world of SAIDs, including mechanistic pathways of autoinflammation, pathogenesis, and treatment. We hope this review helps rheumatologists to gain an updated understanding of SAIDs.

Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenitis Syndrome and Syndrome of Unexplained Recurrent Fevers in Children and Adults

Children and adults with autoinflammatory disorders, who often experience recurrent fevers, rashes, cold-induced symptoms, conjunctivitis, lymphadenopathy, recurrent infections, aphthous stomatitis, and abnormal blood cell counts, may present to the allergist/immunologist because the symptoms mimic allergies and disorders of immunity. In recent years, there has been increased recognition of non-monogenic autoinflammatory disorders, including periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome and syndrome of undifferentiated recurrent fevers. For many clinical practitioners, the natural history, diagnostic criteria, differential diagnoses, and preferred therapies remain challenging because of the presumed rarity of patients and the evolving field of autoinflammation. Here, we aim to provide a practical framework for the clinical allergist/immunologist to evaluate and treat this patient population.

Periodic Fever in Children: Etiology and Diagnostic Challenges

Periodic fever in children is an autoinflammatory illness with an unknown cause. Symptoms include frequent episodes of fever that are followed by an increase in inflammatory markers. A genetic background for periodic fever of unknown origin has been hypothesized, based on its family clustering and parallels to other autoinflammatory illnesses such as familial Mediterranean fever. Genome analysis has been used in studies to look for related gene variations in periodic fever of unknown origin in the pediatric population. 

Children with periodic fevers might be a diagnostic challenge. After ruling out the most prevalent causes, a wide variety of other possibilities are investigated. Infectious and noninfectious causes of periodic fever in children are discussed in this article.

Inflammasomes (intracellular proteins that activate interleukin (IL)-1b and IL-18) and genetic/hereditary variations are thought to be implicated in the pathogenesis of periodic fever. Evaluation and ruling out possible infective or noninfective causes is vital in the diagnosis of periodic fever in children. Investigations demonstrate that there isn't a single gene linked to it, suggesting that it may have a multifactorial or polygenic origin, with an environmental trigger causing inflammasome activation and fever flares. Treatment is usually symptomatic, with drugs such as colchicine and cimetidine having shown promising results in trials.

We explored the literature on periodic fever in children for its epidemiology, pathophysiology, the role of various genes and how they influence the disease and associated complications, and its various treatment modalities.

Çocuk Ailesel Akdeniz Ateşi Hastalarında MEFV Mutasyonlarının Dağılımı: Türkiye’nin Güneydoğusunda Tek Merkezli Çalışma

Amaç: Ailevi Akdeniz Ateşi (FMF), Akdeniz'de yaşayan etnik gruplarda (Türkler, Araplar, Yahudiler ve Ermeniler) görülen resesif geçişli otoinflamatuvar bir hastalıktır. Farklı coğrafi bölgelerde ve etnik gruplarda FMF’ deki MEFV mutasyon değişimi farklılık göstermektedir. Bu çalışmada, son yıllara ait mutasyon dağılımını belirleyerek bölgemizdeki MEFV mutasyon dağılım verileri ile ülke geneli ve diğer bölgelerin mutasyon dağılımını karşılaştırmayı amaçladık. Yöntemler: Merkezimize sevk edilen FMF klinik semptomları tespit edilen 286 hastanın moleküler test sonuçlarını değerlendirdik. Moleküler analiz için hastaların, pyrosequencing yöntemi kullanılarak MEFV genindeki 22 yaygın mutasyon analizi yapıldı. Bulgular: 286 hastanın genetik analizi sonucu; 74 (%25,87) hastanın 27’sinin homozigot (%9,44),47’ sinin bileşik heterozigot (%16,44) mutasyona sahip olduğunu, 212'sinin (%74,13) isesadece tek bir mutasyon taşıdığını ortaya koydu. Allel frekansları göz önüne alındığında en yaygın mutasyonlar; E148Q (%32,50), M694V (%26,94), V726A (%10,83), R761H (%10,83), M680I (G>C) (%6,11) ve P369S (%5,56) şeklindedir. Sonuç: Bu tek merkezli çalışmada, Türkiye'nin güneydoğusundaki çocuk FMF hastalarından elde edilen yaygın MEFV gen mutasyonlarının sıklıkları hakkında bilgi verdik. Hastaların yaklaşık yarısı alellerinde en az bir E148Q veya M694V mutasyonu taşıyordu. Bölgemizdeki verileri ülke geneli ve Ege bölgesi ile karşılaştırdığımızda en sık rastlanan mutasyon açısından farklılıklar olduğu gözlenmektedir. Çalışma sonuçlarımız ülkemizin Güneydoğu Anadolu Bölgesinde yapılan önceki çalışmalarla karşılaştırıldığında, mutasyon oranları arasında farklılıklar olduğu gözlemlenmektedir. Bu çalışmayla bölgemizdeki FMF hastalarının mutasyon dağılımlarının güncel verileri elde edilerek literatüre katkıda bulunulmuştur.

Inflammation: A New Look at an Old Problem

Pro-inflammatory stress is inherent in any cells that are subject to damage or threat of damage. It is defined by a number of universal components, including oxidative stress, cellular response to DNA damage, unfolded protein response to mitochondrial and endoplasmic reticulum stress, changes in autophagy, inflammasome formation, non-coding RNA response, formation of an inducible network of signaling pathways, and epigenetic changes. The presence of an inducible receptor and secretory phenotype in many cells is the cause of tissue pro-inflammatory stress. The key phenomenon determining the occurrence of a classical inflammatory focus is the microvascular inflammatory response (exudation, leukocyte migration to the alteration zone). This same reaction at the systemic level leads to the development of life-critical systemic inflammation. From this standpoint, we can characterize the common mechanisms of pathologies that differ in their clinical appearance. The division of inflammation into alternative variants has deep evolutionary roots. Evolutionary aspects of inflammation are also described in the review. The aim of the review is to provide theoretical arguments for the need for an up-to-date theory of the relationship between key human pathological processes based on the integrative role of the molecular mechanisms of cellular and tissue pro-inflammatory stress.