Anakinra Drug Retention Rate and Predictive Factors of Long-Term Response in Systemic Juvenile Idiopathic Arthritis and Adult Onset Still Disease

Cardiovascular involvement in children with COVID-19 temporally related multisystem inflammatory syndrome (MIS-C): can cardiac magnetic resonance arrive to the heart of the problem?

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) shows a significant overlap of symptoms with other hyper-inflammatory diseases such as Kawasaki disease (KD), but the real difference of the two conditions is still matter of debate. Coronary artery lesions (CAL) are the most relevant complication in KD. Nonetheless, CAL, myocarditis, pericarditis, arrhythmia are the main cardiovascular complications in MIS-C. A close clinical assessment is mandatory, both at the diagnosis and during the follow-up, by ECG and echocardiography. Cardiac magnetic resonance (MRI) adds important data to ultrasound findings. However, cardiac MRI studies in MIS-C are limited to a small number of cohorts.

METHODS

We enrolled 20 children (age:1-16 years; 11 F; 9 M) with cardiac involvement secondary to MIS-C, all evaluated by cardiac MRI.

RESULTS

8 children showed pathological cardiac MRI: 2 showed pericardial effusion; 2 showed myocardial oedema; 1 showed aortic insufficiency; 3 showed delayed enhancement (one for acute myocarditis with oedema; 2 for myocardial fibrosis). Delayed enhancement was reduced significantly 5.6-9 months after the first MRI evaluation. 25% of patients with pathological MRI had CAL associated with valvular insufficiency of 2 valves. 17% of patients with normal MRI had CAL, associated with valvular insufficiency of 1 valve in 1 patient. The correlations between haematological, clinical, cardiologic parameters, treatment, did not reach the statistical significance. 4 patients were treated with anakinra. Among those, 2 patients showed a normal cardiac MRI. Cardiac lesions resolved in all the patients during the follow-up. Some patients with pathological cardiac MRI could not underwent a control with MRI, for the low compliance. However, echocardiography and ECG, documented the resolution of the pathological data in these cases.

CONCLUSIONS

A higher risk of CAL was documented in patients with an association of other cardiac lesions. Cardiac MRI is difficult to perform routinely; however, it is useful for evaluating the acute myocardial damage and the outcome of patients with MIS-C.

The latest advances in the use of biological DMARDs to treat Still's disease

INTRODUCTION

Currently, the therapeutic management of Still's disease, a multisystemic inflammatory rare disorder, is directed to target the inflammatory symptoms and signs of patients. The treatment varies from glucocorticoids to disease-modifying antirheumatic drugs (DMARDs), both conventional synthetic and biological (bDMARDs). Usually, in refractory patients, bDMARDs are administered.

AREAS COVERED

Among bDMARDs, IL-1 and IL-6 inhibitors are frequently used, as data reported from both clinical trials and 'real-life' experiences. Recently, innovative therapeutic strategies have suggested an early administration of bDMARDs to increase the rate of clinical response and drug-free remission. Some new targets have been also proposed targeting IL-18, IFN-γ, and JAK/STAT pathway, which could be applied to Still's disease and its life-threatening evolution.

EXPERT OPINION

Many lines of evidence improved the knowledge about the therapeutic management of Still's disease with bDMARDs. However, many unmet needs may be still highlighted which could provide the basis to arrange further specific research in increasing the rate of clinical response. In fact, Still's disease remains a highly heterogeneous disease suggesting possible diverse underlying pathogenic mechanisms, at least partially, and consequent different therapeutic strategies. A better patient stratification may help in arranging specific studies to improve the long-term outcome of Still's disease.

Risk of Macrophage Activation Syndrome in Patients with Adult-Onset Still's Disease Treated with IL-1 and IL-6 Inhibitors: A Meta-analysis and Single-Center Experience

INTRODUCTION

Patients with adult-onset Still's disease (AOSD) are at risk of developing macrophage activation syndrome (MAS), a life-threatening condition. Some cases of MAS have been reported following the use of biological agents, highlighting the need to identify contributing factors. This study aims to examine the characteristics of MAS in patients with AOSD treated with anakinra (ANA) or tocilizumab (TCZ).

METHODS

A systematic search was conducted across four online databases to identify studies reporting the incidence rates of MAS in patients with AOSD treated with ANA or TCZ. Meta-analysis was performed using a random-effects model and the generic inverse variance method to estimate the pooled incidence rates. The difference in incidence rates of MAS between TCZ and ANA was assessed. Additionally, we analyzed laboratory data and clinical features of AOSD cases at our institution, stratifying them into two groups: those who developed MAS after TCZ administration and those who did not.

RESULTS

Of the 455 screened articles, we included five ANA and six TCZ studies. The pooled incidence rates of MAS were 1.50% (95% confidence interval [CI], 0-3.36) for ANA (345 patients) and 14.01% (95% CI 4.51-23.51) for TCZ (94 patients). MAS incidence was significantly higher in the TCZ group (P = 0.01). Among the 17 patients from our institution, the six patients who developed MAS had significantly higher white blood cell and neutrophil counts, as well as elevated levels of lactate dehydrogenase, C-reactive protein, and ferritin before TCZ induction (P < 0.05).

CONCLUSIONS

In patients with AOSD, the manifestation of MAS is influenced by multiple causative factors. Consequently, the administration of TCZ should be approached with caution, particularly in patients exhibiting elevated inflammatory markers.

TRIAL REGISTRATION

This study was registered with the Clinical Trial Registry of the University Hospital Medical Information Network (Japan) as UMIN000049243.

"Neuroimmunoendocrinology" in Children with Rheumatic Diseases: How Glucocorticoids Are the Orchestra Director

The neural, the endocrine, and the immune systems are studied as distinct districts in physiological and pathological settings. However, these systems must be investigated with an integrative approach, while also considering that therapeutic agents, such as glucocorticoids, can induce a reversible or irreversible change of this homeostasis. Children and adolescents affected by rheumatic diseases frequently need treatment with corticosteroids, and the treatment must sometimes be continued for a long time. In the biological era, the treat-to-target strategy allowed a real revolution in treatment, with significant steroid dose sparing or, in many patients, steroid treatment withdrawal. In this review, the impact of glucocorticoids on endocrine, immune, and neurologic targets is analyzed, and the crosstalk between these systems is highlighted. In this narrative review, we explore the reasoning as to why glucocorticoids can disrupt this homeostasis, we summarize some of the key results supporting the impact of glucocorticoids treatment on endocrine, immune, and neurologic systems, and we discuss the data reported in the international literature.

Performance of the modified Systemic Manifestation Score for systemic juvenile idiopathic arthritis in Adult-onset Still's disease

OBJECTIVES

To compare the ability of the modified Systemic Manifestation Score (mSMS) and the mPouchot score to distinguish adult-onset Still's disease (AOSD) with high disease severity in a large cohort.

METHODS

We scored the disease severity of 174 patients and categorized them into high and low disease severity states. The correlation of mSMS and mPouchot score with ESR, CRP, ferritin, liver function tests, and serum cytokines was investigated. Receiver operator characteristic (ROC) curve and logistic regression analysis were performed to compare the ability of mSMS and mPouchot to distinguish patients with severe AOSD.

RESULTS

Both mSMS and mPouchot score were positively correlated with ESR (both P < 0.001), CRP (both P < 0.0001), and serum ferritin (both P < 0.0001). Moreover, both mSMS and mPouchot score are significantly associated with liver dysfunction and high IL-18 (both P < 0.0001) and IL-6 (both P < 0.01) levels in AOSD patients. Furthermore, the area under curve (AUC) value of mSMS was significantly less than of mPouchot score (0.71 for mSMS, 0.81 for mPouchot score, P < 0.0001). Compared with mPouchot score, mSMS had higher sensitivity (75.64% vs 74.36%) and lower specificity (55.06% vs 76.40%). And mSMS had a worse performance in assessing high disease severity than mPouchot score in logistic analysis.

CONCLUSION

Both scores are proven as effective to assess disease severity of AOSD. By contrast, mSMS perform worse in assessing high disease severity of AOSD patients than mPouchot score. Key Points • Both modified Systemic Manifestation Score (mSMS) and modified Pouchot score (mPouchot score) positively correlated with ESR, CRP, and serum ferritin of AOSD patients. • Both scores are significantly associated with impaired liver function and high serum cytokine levels. • mSMS had lower discriminative ability than mPouchot score to distinguish high disease severity of AOSD patients.

Rare, rarer, lung involvement in adult-onset Still's disease: A mini-review

Adult-onset Still's disease (AOSD) is a polygenic systemic autoinflammatory disease which is associated with increased morbidity and mortality. Pulmonary involvement is a rare, but serious complication of AOSD. As in AOSD, IL-1b, IL-18, and IL-6 dominate the molecular pathogenesis, which mediate a type 1 and type 3 inflammatory signature of the adaptive immune system. This is evidenced by the success of IL-1- and IL-6 inhibition in the management of AOSD. However, anaphylactic reactions to treatment with IL-1- or IL-6-inhibitors is currently being discussed as a potential trigger for lung involvement inf AOSD, while genetic risk factors have also been identified. Clinically, pulmonary involvement in AOSD can manifest in many different forms. Parenchymal inflammation with peripheral consolidations is the most frequent form while PAH is less common, but often very difficult to manage. This mini-review provides an overview of the pathophysiology as well as the clinical presentation and the diagnostic features of pulmonary involvement in AOSD.

New onset systemic lupus erythematosus after COVID-19 infection: a case report

COVID-19 is a respiratory viral illness that can have life threatening complications. While the short-term sequela of COVID-19, including cytokine storm, is relatively well known, the long-term complications of COVID-19 infection on the immune system is still unknown. There have been some reported cases of autoimmune disease development after COVID-19 infection. We present a patient with a history of COVID-19 infection one month prior who presented with non-specific symptoms including fatigue, malaise, bilateral lower extremity swelling and shortness of breath. His laboratory evaluation and physical exam showed him to be in acute renal failure. Further workup and kidney biopsy results confirmed systemic lupus erythematosus (SLE). Our patient needed treatment with plasmapheresis and immunosuppressants, and subsequently had significant improvement in his symptoms. We discuss the current 2019 European Alliance of Associations for Rheumatology/American College of Rheumatology (EULAR/ACR) diagnostic criteria for SLE and describe plausible mechanisms of COVID-19 induced lupus such as B-cell activation by the virus. We also explore the role of interferons in the potential development of autoimmune diseases after COVID-19 infection and highlight the need for further research in the area.

Systemic Juvenile Idiopathic Arthritis/Pediatric Still's Disease, a Syndrome but Several Clinical Forms: Recent Therapeutic Approaches

BACKGROUND

Systemic Juvenile Idiopathic Arthritis (SJIA)/Pediatric Still's disease is associated with different phenotypes and outcomes from currently available treatments.

METHODS

A review of opinion, based on personal experience in a reference pediatric rheumatology center and key publications, to explore the most important questions regarding disease heterogeneity and treatment approaches.

RESULTS

A few situations deserve particular attention: 1/patients with recent-onset SJIA who may benefit from a treat-to-target approach with a key place for interleukin (IL)-1 inhibition; 2/SJIA patients refractory to Il-1 and IL-6 antagonists in whom several options may be discussed, including thalidomide or allogeneic hematopoietic stem cell transplantation; 3/SJIA patients with macrophage activation syndrome who may benefit from both well-used classical treatment and innovative approaches, such as anti-interferon gamma therapy or Janus Kinase (JAK) inhibitors; 4/SJIA with severe lung involvement, 5/SJIA patients who achieve complete remission on treatment, with some recent evidence that treatment may be reduced in intensity but not so easily withdrawn.

CONCLUSIONS

a case-by-case discussion with expert teams is recommended in this heterogeneous, often difficult-to-treat population of patients.

Update on the therapy of adult-onset Still's disease with a focus on IL-1-inhibition: a systematic review

Introduction:

The past decade has seen increasingly rapid advances in understanding the pathogenic nature of adult-onset Still’s disease (AOSD) and its shared symptoms with the systemic juvenile idiopathic arthritis (sJIA). Interleukin-1 (IL-1) blocking agents are key elements in the treatment. In this updated systematic review, we focus on studies on efficacy and safety of IL-1 blockers published in the past 5 years and review on latest available therapies.

Methods:

We conducted searches using Medline, Biosis, Embase, and Cochrane databases between 2016 and 2021 using the terms AOSD, IL1, IL-18, canakinumab, anakinra, tadekinig, and rilonacept and if applicable their trade names. Duplicates, case reports, and manuscripts with incomplete data were excluded.

Results:

Of the 1013 screened publications, 17 were eligible after careful selection. We only found two published randomized controlled studies in the past 5 years. Review manuscripts of rare diseases, like our work, usually rely on retrospective studies and case series. Anakinra and canakinumab can be successfully used as first- or further-line treatment in patients with AOSD refractory to steroids. A homogeneous outcome is not established yet. Thus, a combination of clinical and laboratory tests can support the experienced clinician in the decision-making process.

Conclusion:

The approval of IL-1 inhibitors for AOSD brought us into a new era in the treatment of AOSD. The overall efficacy-safety profile of the IL-1 inhibitors is favorable reflecting a targeted approach as standard of care. We can expect that the successful treatment of AOSD with IL-1 inhibition will facilitate further clinical and basic research with impact on other auto-inflammatory and hyper-inflammatory conditions.

Drug survival of anakinra and canakinumab in monogenic autoinflammatory diseases: observational study from the International AIDA Registry

OBJECTIVES

To investigate survival of interleukin (IL)-1 inhibitors in monogenic autoinflammatory disorders (mAID) through drug retention rate (DRR) and identify potential predictive factors of drug survival from a real-life perspective.

PATIENTS AND METHODS

Multicentre retrospective study analyzing patients affected by the most common mAID treated with anakinra or canakinumab. Survival curves were analyzed with the Kaplan-Meier method. Statistical analysis included a Cox-proportional hazard model to detect factors responsible for drug discontinuation.

RESULTS

Seventy-eight patients for a total of 102 treatment regimens were enrolled. The mean treatment duration was 29.59 months. The estimated DRR of IL-1 inhibitors at 12, 24, and 48 months of follow-up was 75.8%, 69.7% and 51.1%, respectively. Patients experiencing an adverse event had a significantly lower DRR (p = 0.019). In contrast, no significant differences were observed between biologic-naïve patients and those previously treated with biologic drugs (p = 0.985) Patients carrying high-penetrance mutations exhibited a significantly higher DRR compared with those with low-penetrance variants (p = 0.015). Adverse events were the only variable associated with a higher hazard of treatment withdrawal (HR 2.573 [CI: 1.223-5.411], p = 0.013) on regression analysis. A significant glucorticoid-sparing effect was observed (p < 0.0001).

CONCLUSIONS

IL-1 inhibitors display an excellent long-term effectiveness in terms of DRR, and their survival is not influenced by the biologic line of treatment. They display a favorable safety profile, that deserves however a close monitoring given its impact on treatment continuation. Special attention should be paid to molecular diagnosis and mutation penetrance, as patients carrying low-penetrance variants are more likely to interrupt treatment.

Off-label use of anti-IL-1 drugs in rheumatic diseases

Interleukin-1 (IL-1) plays a key role in the pathogenesis of different rheumatic diseases. There are now several agents available on the market capable of blocking IL-1. The proven effectiveness and excellent safety of these drugs makes them a possible therapeutic option in the treatment of IL-1 driven diseases, when previous therapies are contraindicated or ineffective. This article discusses the European wide off-label use of these drugs for the treatment of rheumatic diseases.

Serum Heparin-Binding Protein as a Potential Biomarker to Distinguish Adult-Onset Still's Disease From Sepsis

Adult-onset Still’s disease (AOSD) is a systemic, multifactorial, autoinflammatory disease for which the etiopathogenesis is not well understood. Given the similarities in clinical and laboratory features between this disease and sepsis, and the differences in treatment strategies for these two diseases, specific diagnostic markers are crucial for the correct diagnosis and management of AOSD. Previous studies have shown plasma heparin-binding protein (HBP) is a promising potential biomarker for AOSD; thus, this study aimed to detect serum HBP levels in patients with AOSD or sepsis to assess its potential as a biomarker for differential diagnosis. We found that serum HBP levels were significantly higher in patients with active AOSD than that in those with inactive AOSD. Patients with sepsis had higher serum HBP levels compared with those who had active or inactive AOSD. We calculated the area under the receiver operating characteristic (ROC) curve to assess whether HBP could be used to differentiate active from inactive AOSD; this was 0.811 with sensitivity 0.650, specificity 0.811, and cutoff HBP value of 35.59 ng/ml. The area under the ROC curve for HBP as a biomarker to differentiate AOSD from sepsis was 0.653, with sensitivity 0.759, and specificity 0.552, and cutoff HBP value of 65.1 ng/ml. Taken together, the results of our study suggest that serum HBP could be a useful diagnostic biomarker to evaluate disease activity in patients with AOSD, and to differentiate AOSD from sepsis.

Interleukin-1 Blockade in Polygenic Autoinflammatory Disorders: Where Are We now?

Polygenic autoinflammatory diseases (AIDs), such as systemic juvenile idiopathic arthritis (sJIA), adult-onset Still's disease, Kawasaki disease, idiopathic recurrent pericarditis (IRP), Behçet’s Syndrome, Crystal-induced arthropatihes such as gout or Calcium pyrophosphate deposition disease are characterized by the overexpression of inflammasome-associated genes, leading to a dysregulation of the innate immune response. 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, IL-33) was defined to be principally responsible for the inflammatory nature of polygenic AIDs. Several clinical trials were initiated, and IL-1 blockade has been proven to cause a rapid reduction of clinical symptoms and normalization of laboratory parameters in the majority of cases. Randomized, placebo-controlled, clinical trials, together with registry-based clinical trials and open-label, retrospective and prospective observational studies, supported the efficacy and safety of IL-1 inhibitors in the treatment of polygenic AIDs. Most of the current data are focused on the therapeutic use of anakinra, an IL-1 receptor antagonist, canakinumab, an anti-IL-1β monoclonal antibody, and rilonacept, a soluble decoy receptor. However, other promising agents, such as gevokizumab, IL-1β blocking monoclonal antibody, tadekinig alfa, a human recombinant IL-18-binding protein, and tranilast, an analog of a tryptophan metabolite, are currently being tested. Anakinra, canakinumab and rilonacept caused impressive improvements in both systemic and musculoskeletal symptoms. Furthermore, the anti-IL-1 therapy allowed corticosteroid tapering and, in some cases, even withdrawal. This article reviews the current IL-1 inhibitors and the results of all clinical trials in which they have been tested for the management of broad spectrum of polygenic AIDs.

Drug retention rates of biological agents in adult onset Still's disease

OBJECTIVES

To assess drug retention rates (DRRs) and reasons for discontinuation of biologic disease-modifying antirheumatic drugs (bDMARDs) in a large monocentric cohort of patients with adult onset Still's disease (AOSD).

METHODS

Clinical data of AOSD patients treated with at least one bDMARD and followed up at our Center were retrospectively evaluated. Data about disease duration, number of previous bDMARDs, concomitant treatments, and reasons for therapy discontinuation were collected. Survival curves were examined by the Kaplan-Meier method and compared using a stratified log-rank test. 24-month DRRs were calculated for each bDMARD. Hazard ratio (HR) for previous bDMARD use was evaluated.

RESULTS

Forty-two AOSD patients received a total of 79 bDMARD-courses. Anakinra (ANK; n = 41) was the most frequently used bDMARD, followed by tocilizumab (TCZ; n = 21) and Tumor Necrosis Factor inhibitors (TNFi; n = 17). Biologic agents were administered concomitantly with prednisone in all cases (mean dose, 23 ± 18 mg/day) and with csDMARD therapy in 54 (68%) of courses. Thirty-six (46%) treatment courses were discontinued by 24 months. DRRs at 24 months were 62.5% for TCZ, 53.1% for ANK, and 11.8% for TNFi. ANK and TCZ DRRs were similar (p = 0.576), but significantly higher than TNFi (p = 0.015). Previous biologic therapies did not impact DRR (HR 0.73, 95% CI = 0.40 - 1.31, p = 0.288).

CONCLUSIONS

In our AOSD study population, 24 months DRRs of TCZ and ANK were similar and significantly higher than the TNFi DRR. Previous use of biologic agents did not affect DRRs.

New treatment for myocardial diseases

Treatment of myocardial diseases with renin-angiotensin system inhibitors and β-blockers has greatly contributed to improving prognosis. However, these treatments are non-specific, and with the exception of some treatments, radical treatments according to the cause of each disease have not been developed until recent years. But in the past decade, more specific and more upstream treatments based on the molecular mechanism of disease onset have been developed and are emerging. Some of the effects have been shown in clinical practice and already approved. This article outlines the mechanism of action and clinical data of novel therapeutic agents specific for myocardial diseases such as dilated cardiomyopathy, hypertrophic cardiomyopathy, Fabry disease, cardiac amyloidosis, and myocarditis. In the future, we hope that the molecular mechanisms will be further elucidated and new and upstream treatment methods will be developed.

Current treatment options and safety considerations when treating adult-onset Still's disease

INTRODUCTION

Adult onset Still disease (AOSD) is a rare systemic inflammatory condition. The clinical spectrum of this disease ranges from self-limiting forms with mild symptoms to life-threatening cases. Glucocorticoids and non-steroidal anti-inflammatory drugs (NSAIDs) represent the first line of therapy for AOSD, with add-on therapy with second-line drug reserved to steroid-dependent patients and in life-threatening cases. Currently, early treatment with conventional disease modifying anti-rheumatic drugs (DMARDs) and biologic agents blocking causal cytokines is advocated in patients with severe and recalcitrant clinical manifestations.

AREAS COVERED

This review analyzes the available controlled evidence and observational data regarding the efficacy and safety of conventional and biological pharmacological agents in the treatment of AOSD.

EXPERT OPINION

Non-steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids are effective in controlling clinical manifestations in the majority of AOSD patients. Conventional DMARDs can be 20 effective in some severe and steroid-dependent cases of AOSD; however, anti-cytokine agents represent an effective and overall more suitable alternative in this specific subset of patients. IL-1 and IL-6 blockade are effective in treating systemic and articular inflammation of AOSD patients. IL-1 blockade also has an excellent safety profile and therefore represent the first choice of biologic treatment in this clinical scenario.

Successful treatment of interstitial pneumonitis with anakinra in a patient with adult-onset Still's disease

A 29-year-old African woman with active adult-onset Still's disease (AOSD) that developed at the end of 2018 presented to our hospital in September 2019 with pleuritic right-sided pain and respiratory insufficiency of almost a month's duration, which had failed to respond to high-dose corticosteroid and antibiotic treatment. A thoracic CT revealed right pleural effusion, multiple consolidations and pulmonary collapse. Besides pulmonary symptoms, the patient had arthralgia, fever, a salmon-coloured rash, leucocytosis and rising inflammatory markers. After an AOSD flare diagnosis was established, intravenous methylprednisolone and painkillers were administered. Due to the severity of the pleural effusion and the lack of response to previous treatments, subcutaneous anakinra was started. Two days after the first dose the patient had almost fully recovered. The success of this case points out the potential effectiveness of anakinra in the prevention of a pulmonary failure and the treatment of a severe intermittent polycyclic pattern of AOSD.

Pro-inflammatory properties of H-ferritin on human macrophages, ex vivo and in vitro observations

Ferritin is an iron-binding molecule, which comprises 24 subunits, heavy (FeH) and light (FeL) subunits, suggested to have a pathogenic role by the 'hyperferritinemic syndrome'. In this work, we tested (1) FeH and FeL in bone marrow (BM) and sera in patients with macrophage activation syndrome (MAS); (2) pro-inflammatory effects of ferritin, FeL, and FeH on macrophages; (3) ability of FeH-stimulated macrophages to stimulate the proliferation of peripheral blood mononuclear cells (PBMCs); (4) production of mature IL-1β and IL-12p70 in extracellular compartments of FeH-stimulated macrophages. Immunofluorescence analysis and liquid chromatography mass spectrometry (LC-MS/MS) based proteomics were performed to identify FeL and FeH in BM and sera, respectively, in the same patients. Macrophages were stimulated with ferritin, FeH, and FeL to assess pro-inflammatory effects by RT-PCR and western blot. The proliferation of co-cultured PBMCs with FeH-stimulated macrophages was tested. Immunofluorescence showed an increased FeH expression in BMs, whereas LC-MS/MS identified that FeL was mainly represented in sera. FeH induced a significant increase of gene expressions of IL-1β, IL-6, IL-12, and TNF-α, more marked with FeH, which also stimulated NLRP3. FeH-stimulated macrophages enhanced the proliferation of PBMCs. The ELISA assays showed that mature form of IL-1β and IL-12p70 were increased, in extracellular compartments of FeH-stimulated macrophages. Our results showed FeH in BM biopsies of MAS patients, whereas, LC-MS/MS identified FeL in the sera. FeH showed pro-inflammatory effects on macrophages, stimulated NLRP3, and increased PBMCs proliferation.