Dysregulated production of interleukin-1β upon activation of the NLRP3 inflammasome in patients with familial Mediterranean fever

The roles of SFKs in the regulation of proinflammatory cytokines and NLRP3 in familial mediterranean fever patients

Familial Mediterranean Fever (FMF) is caused by mutations in pyrin, a protein produced in innate immune cells that regulates the development of interleukin (IL)-1β by interacting with caspase-1 and other components of inflammasomes. Although overexpression of proinflammatory cytokines have been observed in FMF patients, no studies have been conducted on the role of Src family kinases (SFKs). The purpose of this study was to examine the impact of SFKs on the modulation of IL-1β, IL-6, IL-8, TNF-α, and NLRP3 inflammasome in patients with FMF. The study included 20 FMF patients and 20 controls. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation. Protein expression levels of SFKs members were measured by western blot. The effect of lipopolysaccharide-induced (LPS) activation and PP2- induced inhibition of SFKs on NLRP3 and IL-1β, IL 6, IL-8, TNF-α were examined by western blot and flow cytometry respectively. Patients with FMF have considerably greater levels of Lck expression. In addition, patients had a substantially greater basal level of NLRP3 than the control group (*p = 0.016). Most importantly, the levels of IL-1 β were elevated with LPS stimulation and reduced with PP2 inhibition in FMF patients. These results suggest that SFKs are effective in regulation of IL-1 β in FMF patients.

Real-life data on tapering or discontinuation of canakinumab therapy in patients with familial Mediterranean fever

This study aimed to investigate the disease characteristics of familial Mediterranean fever (FMF) patients undergoing dose optimisation and discontinuation of canakinumab therapy. A total of 61 patients diagnosed with FMF and using canakinumab for the resistant disease were enrolled on this retrospective study. Patients’ characteristics, disease activity, treatment response, dose optimisation, dose intervals, attack-free periods, drug-free periods and side effects were noted. Dose intervals were extended in patients who achieved remission without being bound by any protocol at the discretion of the rheumatology physician who followed up with the patients in the outpatient clinic. The drug was discontinued in some patients whose dose intervals were 2 months or longer and remained in remission for 6 months or longer. A total of 57 patients (56% female, median age 32.4 years) were included. The mean attack frequency before canakinumab was 3.4/6 months, while it was 1.2 at the last post-treatment visit (p < 0.001). The median duration of canakinumab use was 46 months. After the first 6 months, the dosing interval was extended in 22 patients, and then treatment was discontinued in 12 of them who did not have an attack in the last 6 months. Three of the 12 patients whose treatment was discontinued started monthly treatment again after their attacks recurred. In the remaining ten patients, dose intervals were extended to 8–12 weeks after 6 months of monthly treatment. Nine patients are still being followed up without attacks and receive only colchicine therapy. Canakinumab is a safe and effective treatment, dose intervals may be extended, and follow-up without medication may be possible for eligible patients. However, there is a need for a consensus on dose optimisation or tapering.

Clinical perspectives and therapeutic strategies: pediatric autoinflammatory disease-a multi-faceted approach to fever of unknown origin of childhood

Among the different etiologies for fever of unknown origin in children, infectious diseases are the most frequent final diagnosis, followed by autoimmune diseases and malignancies. Autoinflammatory diseases are relatively rare among children and are frequently overlooked as differential diagnoses for fever of unknown origin. Once the possibility of a particular autoimmune disease is considered by physicians, the diagnosis might be easily made by a genetic approach because many of autoinflammatory diseases are of monogenic origin. To reach the diagnosis, detailed history-taking, precise physical examinations, and cytokine profiling as well as extensive mutation analysis of candidate genes should be undertaken for febrile children. Such the approach will protect the patients, and their family to undergo “diagnostic odyssey” in which unnecessary and sometimes risky diagnostic and therapeutic interventions are taken.

This short review discusses the clinical and laboratory features of familial Mediterranean fever and systemic juvenile idiopathic arthritis, as representative illnesses of monogenic and polygenic autoinflammatory diseases, respectively. Cytokine profiling and mutation analyses both help to understand and decipher the heterogeneous pathologies in both disease categories.

TRIM Proteins in Inflammation: from Expression to Emerging Regulatory Mechanisms

Inflammation is an immune response to exogenous or endogenous insults that helps to maintain the tissue homeostasis under stressful conditions. Depending on the differential types of insults, inflammation is classified into microbial, autoimmune, metabolic, allergic, and physical inflammation. With regard to its involvement in the pathogenesis of most of human diseases, dissecting the key molecules in the regulation of inflammatory process is vital for the prevention and therapeutics of human diseases. Tripartite motif (TRIM) proteins are a versatile family of E3 ligases, which are composed of > 80 distinct members in humans recognized for their roles in antiviral responses. Recently, a large number of studies have shown the regulatory roles of TRIM proteins in mediating the inflammation. Herein in this review, we discuss the aberrations of TRIM proteins in autoimmune and autoinflammatory diseases, with a focus on the regulation of different components of inflammatory process, including inflammasome, NF-κB signaling, type I IFN (interferon) production, and Th1/Th17 cell differentiation. Importantly, elucidation of the mechanism underlying the regulation of inflammation by TRIMs provides insights into the use of TRIMs as therapeutic targets for disease treatment.

Effect of anti-interleukin-1 treatment on quality of life in children with colchicine-resistant familial Mediterranean fever: A single-center experience

AIM

The aim of this study is to evaluate the clinical parameters, acute-phase reactants, side effects, genetic mutations among colchicine-resistant Familial Mediterranean fever (FMF) patients who received anti-interleukin-1 (anti-IL-1) treatment. We also evaluate the quality of life and school attendance among colchicine-resistant FMF patients, in relation to treatment with anti-IL-1.

INTRODUCTION

Familial Mediterranean fever is the most common inherited autoinflammatory disorder. Although the main treatment of FMF is colchicine, a small group of patients are resistant to colchicine treatment. Anti-IL-1 treatment is promising in colchicine-resistant patients due to excessive IL-1β production in pathogenesis. The aim of this study is to evaluate the quality of life and school attendance rates among colchicine-resistant FMF patients after anti-IL-1 treatment.

METHODS

This is a single center retrospective study of 25 pediatric colchicine-resistant FMF patients treated with anti-IL-1 treatment. Autoinflammatory Disease Activity Index (AIDAI) was used for disease activity assessment. School attendance rates were evaluated before and after treatment.

RESULTS

There were 25 patients with FMF (11 M/14 F) who were treated with anakinra or canakinumab for various indications (colchicine-resistant recurrent febrile attacks in 20, colchicine-related side effects in 2, subclinical inflammation in 3 patients). Only 3 patients developed side effects with anakinra (2 headache, 1 urticarial rash). There was a significant decrease in the frequency of attacks, acute-phase reactants (erythrocyte sedimentation rate and C-reactive protein), AIDAI and physician's and patient's global assessment scores and improvement in school attendance rates. At the last follow-up, all patients were in remission, and only 3 had subclinical inflammation.

CONCLUSION

Anti-IL-1 treatment is quite effective in children with colchicine-resistant FMF patients, proven with improved AIDAI scores and school attendance rates. In the long term by lowering disease activation even development of amyloidosis may be prevented.

Long-term effectiveness and safety of canakinumab in pediatric familial Mediterranean fever patients

Background: Little is known about the long-term efficacy and safety of canakinumab in paediatric FMF patients.Aim: To present the single centre experience of colchicine-resistant paediatric-onset FMF patients who were treated with canakinumab by off-label use since 2012.Methods: The hospital files of 15 children who used canakinumab were retrospectively evaluated. Clinical and laboratory data of each visit were recorded. Drug-related adverse events were recorded. Complete remission was described as no attacks and normal acute phase reactants; partial remission was defined as decrease in severity and rate of attacks and/or elevated acute phase reactants with anti-IL-1 treatment.Results: The average duration of canakinumab use was 23.9 months (min:12, max:58 months). Twelve patients were M694V homozygotes. Eleven patients achieved complete remission after the first dose at 2 months and 12 patients at 6 months. Canakinumab interval was shortened in 2 patients from 150 mg/8 weeks to 150 mg/4 weeks. Except one, 14 patients achieved complete remission by 12 months. Two patients had mild urinary tract infections. One patient had bronchopneumonia requiring hospitalization. Two patients had teeth abscess. There were no serious adverse events such as opportunistic infections, malignancies, or deaths. Besides, no significant laboratory abnormalities occurred in complete blood count parameters, liver and kidney function tests.Conclusion: To the best of our knowledge, this is the longest outcome study about canakinumab use in paediatric FMF patients. This study suggested that canakinumab is safe and effective in children with FMF in the long term.

Metabolic regulation of inflammasomes in inflammation

Inflammasome activation and subsequent inflammatory cytokine secretion are essential for innate immune defence against multiple stimuli and are regarded as a link to adaptive immune responses. Dysfunction of inflammasome activation has been discovered at the onset or progression of infectious diseases, autoimmune diseases and cancer, all of which are also associated with metabolic factors. Furthermore, many studies concerning the metabolic regulation of inflammasome activation have emerged in recent years, especially regarding the activity of the NLRP3 inflammasome under metabolic reprogramming. In this review, we discuss the molecular mechanisms of the interactions between metabolic pathways and inflammasome activation, which exerts further important effects on various diseases.

Deletion of Nlrp3 Augments Survival during Polymicrobial Sepsis by Decreasing Autophagy and Enhancing Phagocytosis

NLRP3 inflammasome is a critical player in innate immunity. Neutrophil recruitment to tissues and effective neutrophil function are critical innate immune mechanisms for bacterial clearance. However, the role of NLRP3 in neutrophil-dependent bacterial clearance in polymicrobial sepsis is unclear. In this study, we evaluated the role of NLRP3 in polymicrobial sepsis induced by cecal ligation and puncture (CLP). Our results showed protection from death in NLRP3-deficient (Nlrp3^-/-) and NLRP3 inhibitor-treated wild-type (C57BL/6) mice. Nlrp3^-/- and NLRP3 inhibitor-treated mice displayed lower bacterial load but no impairment in neutrophil recruitment to peritoneum. However, neutrophil depletion abrogated protection from death in Nlrp3^-/- mice in response to CLP. Intriguingly, following CLP, Nlrp3^-/- peritoneal cells (primarily neutrophils) demonstrate decreased autophagy, augmented phagocytosis, and enhanced scavenger receptor (macrophage receptor with collagenous structure) and mannose-binding leptin expression. These findings enhance our understanding of the critical role of NLRP3 in modulating autophagy and phagocytosis in neutrophils and suggest that therapies should be targeted to modulate autophagy and phagocytosis in neutrophils to control bacterial burden in tissues during CLP-induced polymicrobial sepsis.