Serum Mac-2 binding protein glycosylation isomer and galectin-3 levels in adult-onset Still's disease and their association with cytokines

Background

Autoinflammation with cytokine dysregulation may be implicated in the pathophysiology of adult-onset Still's disease (AOSD); however, the relationship between galectins and cytokines in patients with active AOSD remains unknown. We aimed to examine the relationship between circulating cytokines/chemokines and galectin-3 (Gal-3) or its ligand, Mac-2 binding protein glycosylation isomer (M2BPGi), in Japanese patients with AOSD.

Methods

We recruited 44 consecutive patients diagnosed with AOSD according to the Yamaguchi criteria, 50 patients with rheumatoid arthritis (RA) as disease controls, and 27 healthy participants. Serum M2BPGi levels were directly measured using a HISCL M2BPGi reagent kit and an automatic immunoanalyzer (HISCL-5000). Serum Gal-3 concentrations were measured by enzyme-linked immunosorbent assay. The serum levels of 69 cytokines were analyzed in patients with AOSD using a multi-suspension cytokine array. We performed a cluster analysis of each cytokine expressed in patients with AOSD to identify specific molecular networks.

Results

Significant increases in the serum concentrations of Gal-3 and M2BPGi were found in the serum of patients with AOSD compared with patients with RA and healthy participants (both p <0.001). There were significant positive correlations between serum Gal-3 levels and AOSD disease activity score (Pouchot score, r=0.66, p <0.001) and serum ferritin levels. However, no significant correlations were observed between serum M2BPGi levels and AOSD disease activity scores (Pouchot score, r = 0.32, p = 0.06) or serum ferritin levels. Furthermore, significant correlations were observed between the serum levels of Gal-3 and various inflammatory cytokines, including interleukin-18, in patients with AOSD. Immunosuppressive treatment in patients with AOSD significantly reduced serum Gal-3 and M2BPGi levels (p = 0.03 and 0.004, respectively).

Conclusions

Although both Gal-3 and M2BPGi were elevated in patients with AOSD, only Gal-3 was a useful biomarker for predicting disease activity in AOSD. Our findings suggest that circulating Gal-3 reflects the inflammatory component of AOSD, which corresponds to proinflammatory cytokine induction through inflammasome activation cascades.

Tocilizumab discontinuation after remission achievement in patients with adult-onset Still's disease

OBJECTIVES

Tocilizumab, an IL-6 inhibitor, has been proven effective in patients with adult-onset Still's disease (AOSD). This study aimed to clarify whether tocilizumab can be discontinued after achieving remission and to identify factors relevant to its successful discontinuation.

METHODS

Consecutive patients with AOSD diagnosed according to Yamaguchi's criteria from April 2012 to July 2022, who were treated with tocilizumab, were retrospectively reviewed.

RESULTS

Forty-eight patients with AOSD treated with intravenous tocilizumab, with sufficient information, were included. Thirty-eight patients (79.2%) achieved remission after 6 months of tocilizumab treatment, 12 of whom discontinued tocilizumab during remission. Within 1 year after tocilizumab discontinuation, six patients (50.0%) recurred at a mean of 5.5 months, while the other six (50.0%) remained in remission. Between the non-recurrence and recurrence groups, no difference was found in disease activity at tocilizumab discontinuation (systemic feature score, p = 0.24; ferritin, p = 0.46). While the duration of tocilizumab use was not different (p = 0.32), the interval of tocilizumab administration at tocilizumab discontinuation in the recurrence group was 21 (14-35) days, which tended to be shorter than 35 (28-53) days in the non-recurrence group (p = 0.08). Patients with prednisolone dose < 7 mg/day at last tocilizumab treatment had fewer recurrences than those without (p = 0.001). After recurrence, tocilizumab was resumed in half of the patients, resulting in successful disease control.

CONCLUSIONS

The recurrence rate after tocilizumab discontinuation was 50% in 1 year. Patients who remained in remission with a longer interval of tocilizumab administration and lower prednisolone dose were likely to succeed in the withdrawal of tocilizumab.

Deep Immunophenotyping of Circulating T and B Cells in Relapsing Adult-Onset Still's Disease

Adult-onset Still's disease (AOSD) is a complex systemic inflammatory disorder, categorized as an 'IL-1 driven' inflammasomapathy. Despite this, the interaction between T and B cells remains poorly understood. We conducted a study, enrolling 7 patients with relapsing AOSD and 15 healthy control subjects, utilizing deep flow cytometry analysis to examine peripheral blood T- and B-cell subsets. T-cell and B-cell subsets were significantly altered in patients with AOSD. Within CD4+ T cells, Th2 cells were decreased. Additionally, Th17 cell and follicular Th cell subsets were altered within CD45RA-CD62L+ and CD45RA-CD62L- Th cells in patients with AOSD compared to healthy controls. We identified changes in CD8+ T cell maturation and 'polarization' in AOSD patients, with an elevated presence of the TEMRA CD8+ T cell subset. Furthermore, the percentage of Tc1 cells was decreased, while the frequency of CCR6-CXCR3- Tc2 cells was elevated. Finally, we determined that the frequency of CD5+CD27- B cells was dramatically decreased in patients with AOSD compared to healthy controls. Further investigations on a large group of patients with AOSD are required to evaluate these adaptive immunity cells in the disease pathogenesis.

Unveiling the Mystery of Adult-Onset Still's Disease: A Compelling Case Report

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disorder. Diagnosis can take a long time, especially in the presence of confounding factors, and it is, to some extent, a process of exclusion. AOSD has life-threating complications ranging from asymptomatic to severe, such as macrophage activation syndrome (MAS), which is also referred to as hemophagocytic lymphohistocytosis (HLH). This condition is correlated with cytokine storm production and monocyte/macrophage overactivation and typically occurs with rash, pyrexia, pancytopenia, hepatosplenomegaly and systemic involvement. Exitus occurs in approximately 10% of cases. For the treatment of MAS-HLH, the Histiocyte Society currently suggests high-dose corticosteroids, with the possible addition of cyclosporine A, anti-interleukin (IL)-1, or IL-6 biological drugs; the inclusion of etoposide is recommended for the most severe conditions. In all cases, a multidisciplinary collaboration involving the resources and expertise of several specialists (e.g., rheumatologist, infectiologist, critical care medicine specialist) is advised. Herein, we provide a detailed description of the clinical case of a previously healthy young woman in which MAS developed as a dramatic onset manifestation of AOSD and whose diagnosis posed a real clinical challenge; the condition was finally resolved by applying the HLH-94 protocol (i.e., etoposide in combination with dexamethasone).

Bloody Diarrhea in a 27-year-old Man with Adult-onset Still's Disease

A 27-year-old man presented with quotidian fever, rash, knee arthralgia, sore throat, and bloody diarrhea. Laboratory findings showed neutrophilia, elevated CRP, ferritin, and liver enzyme levels, and decreased hemoglobin levels. Radiological investigations revealed splenomegaly, systemic lymphadenopathy, thickening of the descending colon wall, and an abnormal uptake in the bone marrow and spleen as seen in F-fluorodeoxyglucose positron emission tomography. Malignant lymphoma was initially suspected, but biopsies showed no malignant findings. Colonoscopy revealed mucosal friability, erosions, and shallow ulcers, and pathological findings included crypt abscesses suggestive of either acute infectious colitis or inflammatory bowel disease. The patient was eventually diagnosed with adult-onset Still's disease (AOSD) and started on prednisolone, which resolved bloody diarrhea, leading to the diagnosis of comorbid ulcerative colitis (UC). The combination of AOSD and UC presents a diagnostic challenge due to overlapping symptoms. An accurate diagnosis requires careful exclusion of other diseases and a comprehensive assessment.

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.

Anti-Interleukin-1 Therapy Does Not Affect the Response to SARS-CoV-2 Vaccination and Infection in Patients with Systemic Autoinflammatory Diseases

Patients with systemic autoinflammatory diseases (sAIDs) are a section of the population at high risk of severe COVID-19 outcomes, but evidence on the efficacy of SARS-CoV-2 vaccination in this group of patients is scarce. To investigate the efficacy of SARS-CoV-2 vaccination in patients with sAIDs receiving interleukin-1 (IL-1) inhibition is important. Vaccination and infection responses from 100 sAID patients and 100 healthy controls (HCs) were analyzed. In total, 98% of patients were treated with IL-1 inhibitors at the time of vaccination (n = 98). After the second SARS-CoV-2 vaccination, sAID patients showed similar anti-SARS-CoV-2 antibody responses (mean (standard deviation (SD)): 6.7 (2.7)) compared to HCs (5.7 (2.4)) as well as similar neutralizing antibodies (85.1 ± 22.9% vs. 82.5 ± 19.7%). Anti-SARS-CoV-2 antibody responses and neutralizing antibodies were similar in sAID patients after SARS-CoV-2 infection and double vaccination. Furthermore, while antibodies increased after the first and second vaccination in sAID patients, they did not further increase after the third and fourth vaccination. No difference was found in antibody responses between anakinra and anti-IL-1 antibody treatment and the additional use of colchicine or other drugs did not impair vaccination responses. Primary and booster SARS-CoV-2 vaccinations led to protective antibody responses in sAID patients, which were at the same level of vaccination responses in HCs and in sAID patients after SARS-CoV-2 infection. Immunomodulatory treatments used in sAID do not seem to affect antibody responses to the SARS-CoV-2 vaccine.

Care pathway analysis and evidence gaps in adult-onset Still's disease: interviews with experts from the UK, France, Italy, and Germany

Introduction

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disease of unknown etiology. Published AOSD data are limited, and clinical guidelines were lacking until recently. Managing AOSD remains largely empirical with uncertainties and high variability about the optimal care pathway. Therefore, we used a qualitative approach to collect clinical judgments from the UK, Italy, France and Germany to inform the development of an agreed care pathway. Our work aimed to decrease the uncertainty associated with clinical practice, inform future research in AOSD, and help identify standardized definitions and outcomes in this population.

Methods

Semi-structured interviews and thematic analysis were conducted. Eleven clinicians were interviewed between May and July 2022: four were based in Italy, three in the UK, two in France, and two in Germany.

Results

In this work, we identified the structure of the typical care pathway for AOSD patients, which can be used to inform future economic models in AOSD. The general structure of the pathway was similar across countries. Non-steroidal anti-inflammatory drugs are prescribed during the diagnostic workup while an additive approach is commonly used in confirmed cases: corticosteroids, conventional synthetic disease-modifying antirheumatic drugs, then biologic disease-modifying antirheumatic drugs (bDMARDs) (dose increased before switching). For severe presentations, more aggressive approaches with higher doses and early use of bDMARDs are used. The main elements of variation among countries and clinicians were the criteria used for diagnosis; order of bDMARDs and preferential treatments for articular and systemic patients; and tests for patient monitoring. There is also a lack of standardized outcome measures making comparisons and evidence synthesis challenging.

Conclusion

We identified important evidence gaps for clinical practice, e.g., reliable tests or scores predictive of disease progression and treatment outcome, and recommendations for research, e.g., reporting of compliance rates and use of the Yamaguchi criteria for clinical study inclusion. Consensus is needed around the use of the Systemic score in clinical practice and the clinical utility of this score. A standardized definition of remission is also required in AOSD, and further research should look to identify and validate the specific laboratory markers to be considered when assessing remission.

The causal relationship between multiple autoimmune diseases and nasal polyps

Background

Although previous sporadic studies have reported the associations between a few autoimmune diseases and nasal polyps, these studies have limitations such as conflicting results, small sample sizes, and low levels of evidence.

Methods

Several autoimmune diseases were selected as exposures while the nasal polyps were selected as outcomes. Bidirectional univariable Mendelian randomization and multivariable Mendelian randomization analyses were performed after rigorous screening of instrumental variables. Then mediation analyses were conducted to further investigate the underlying mechanisms.

Results

For the first time, we investigated the causal relationships between nine autoimmune diseases and nasal polyps in different genders and found: (1) there was a causal association between adult-onset Still's disease and nasal polyps; (2) sarcoidosis, ulcerative colitis, type 1 diabetes, and Crohn's disease had no significant associations with nasal polyps; (3) celiac disease showed a suggestive positive association with female nasal polyps, whereas juvenile arthritis and multiple sclerosis showed suggestive positive associations with male nasal polyps. By contrast, arthropathic psoriasis showed a suggestive negative association with nasal polyps. In addition to these nine diseases, previous controversial issues were further investigated: (1) there was a causal relationship between rheumatoid arthritis and nasal polyps, which was partially mediated by "BAFF-R for IgD+ B cells"; (2) ankylosing spondylitis showed suggestive positive associations with the female but not the male nasal polyps. Besides, we validated that there was no causal effect of autoimmune hyperthyroidism on nasal polyps.

Conclusion

Specific conclusions regarding the causal effects of multiple autoimmune diseases on nasal polyps are the same as above. By comparing results between different genders, we have initially observed the sex bimodality in the causal effects between autoimmune diseases and nasal polyps, with those on male nasal polyps being stronger than those on female nasal polyps. Our study lays a solid foundation for further research in the future, not only helping identify individuals susceptible to nasal polyps early but also improving our understanding of the immunopathogenesis of these heterogeneous diseases.

IL-18 in Autoinflammatory Diseases: Focus on Adult Onset Still Disease and Macrophages Activation Syndrome

Interleukin-18 (IL-18) is a potent pro-inflammatory cytokine that is involved in various innate and adaptive immune processes related to infection, inflammation, and autoimmunity. Therefore, it is described as a key mediator of autoinflammatory diseases associated with the development of macrophage activation syndrome (MAS), including systemic juvenile idiopathic arthritis and adult-onset Still's disease. This review focuses on the role of IL-18 in inflammatory responses, placing emphasis on autoinflammatory diseases associated with chronic excess of serum IL-18, which correlate with clinical and biological signs of the disease. Therefore, it is useful for the diagnosis and monitoring of disease activity. Researchers are currently investigating IL-18's role as a therapeutic target for the treatment of inflammatory diseases. The inhibition of IL-18 signaling through recombinant human IL-18BP (IL-18 binding protein) seems to be an effective therapeutic strategy, though further studies are necessary to clarify its importance as a therapeutic target.

Inactivated SARS-CoV-2 vaccine does not increase the risk of relapse in patients with clinically inactive adult-onset Still's disease

OBJECTIVE

A succession of cases have reported flares of adult-onset Still's disease (AOSD) after vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), raising concerns. We aimed to investigate the impact of inactivated SARS-CoV-2 vaccines on disease activity in patients with AOSD.

METHODS

We prospectively enrolled clinically inactive AOSD patients visiting the outpatient clinics of our department. The patients received SARS-CoV-2 vaccines (BBIBP-CorV, Sinopharm, Beijing, China) voluntarily. The occurrence of relapse in the participants was recorded during the follow-up period, and a propensity score matching (PSM) method was used to compare the relapse rates between vaccinated and unvaccinated patients. Localized and systemic symptoms were assessed in the vaccinated patients.

RESULTS

A total of 122 patients with inactive AOSD were included, of which 49.2% (n = 60) voluntarily received the inactivated SARS-CoV-2 vaccine. The relapse rate did not increase significantly in vaccinated patients in comparison with unvaccinated patients (after PSM: 6.8% vs 6.8%), and no relapse occurred within 1 month after vaccination. No obvious adverse reactions were reported in 75.0% of the participants, and none of the patients reported severe reactions.

CONCLUSION

Increased disease activity or relapse following vaccination with inactivated SARS-CoV-2 was rare in patients with inactive AOSD. Local and systemic adverse reactions were found to be mild and self-limiting. These safety profiles of inactivated SARS-CoV-2 vaccines in patients with AOSD may assist in eliminating vaccine hesitancy and increase the vaccination rate against SARS-CoV-2.

Adult-onset Still's disease as the first manifestation of acute myeloid leukemia: a case report

The association between adult-onset Still's disease (AOSD) and malignancy has previously been observed. However, only a limited number of cases described a combination of AOSD and leukemia, none of which reported AOSD-related symptoms as the first manifestation of acute myeloid leukemia (AML). This presentation might represent a paraneoplastic syndrome or leukemic arthritis mimicking AOSD.

Case presentation

Here the authors report a case of a 23-year-old female who fulfilled the Yamaguchi criteria for an AOSD diagnosis. She presented with complaints of polyarthritis, sore throat, and daily fever spikes with the appearance of a nonpruritic maculopapular salmon-colored rash. Her laboratory work showed marked pancytopenia, which led to a bone marrow examination and an AML diagnosis. The patient started receiving chemotherapy with considerable improvement in the AOSD-related symptoms.

Clinical discussion

Patients with underlying malignancies could present with systemic features compatible with AOSD, which necessitates excluding malignancy in any patient with this presentation, specifically in light of some warning signs like pancytopenia.

Conclusion

This case interprets a rare association between AOSD and AML. In addition, it highlights how crucial it is to be aware of the signs that should warn the clinician of a possible underlying malignancy in any patient presenting with AOSD-related symptoms.

Cytokine profile, ferritin and multi-visceral involvement characterize macrophage activation syndrome during adult-onset Still's disease

OBJECTIVES

To multidimensionally characterize macrophage activation syndrome (MAS) complicating adult-onset Still's disease (AOSD) considering cytokine profile, inflammatory markers and multi-visceral involvement of the disease. To perform a high-dimensional phenotypic analysis of circulating immune cells in AOSD patients with and without MAS. To assess interferon (IFN)-related pathways in AOSD synovial tissues by a bulky RNA sequencing.

METHODS

Clinical and biologic data were collected and compared in AOSD patients with and without MAS. Sera biomolecules were analysed by Luminex multiplexing technology. Mass cytometry (CyTOF) was used to characterize circulating immune cells. A bulky RNA sequencing was performed in AOSD synovial tissues.

RESULTS

Forty consecutive AOSD patients were assessed, 14 complicated with MAS. Paralleling with increases of systemic score and ferritin, MAS patients showed higher levels of IL-1α, IL-1β, IL-1Ra, IL-2Ra, IL-6, IL-10, IL-17A, IFN-γ, G-CSF, MCP-1, MIP-1α and SCF. Combining the discriminatory ability of these data in identifying MAS, the best model was composed by systemic score, ferritin, IFN-γ and IL-10. By CyTOF analysis, MAS patients showed an increase of circulating 'classical monocytes' and a reduction of total NK cells. Our assessment showed 3477 IFN-related genes (IRGs) were differently expressed in AOSD synovial tissues.

CONCLUSIONS

A multidimensional characterization of AOSD patients suggested that IFN-γ, IL-10, ferritin and systemic score discriminated the occurrence of cytokine storm syndrome associated with MAS. The inflammatory milieu of AOSD and MAS may be related to a signature of circulating immune cells. Finally, our results about IRGs reinforced the role of IFN-γ in these patients.

Bilateral dacryoadenitis in adult-onset Still's disease: A case report

We present an unusual case of bilateral dacryoadenitis in a middle-aged patient with adult-onset Still's disease (AOSD). We reviewed relevant clinical studies addressing the association between lacrimal lesions and AOSD. A 50-year-old Chinese woman with a 4 year history of recurrent fever and rashes was admitted to the hospital. She had also developed nodules on both eyelids 10 months before admission. After undergoing resection of the left lacrimal gland, the patient received steroids and immunosuppressive therapy. The patient showed good postoperative recovery during the 20 month follow-up. In this case, the pathological examination conducted after orbital surgery helped clinicians differentiate between dacryoadenitis and other orbital lesions. In a review of the literature, dacryoadenitis occurred after the onset of AOSD, and all cases showed non-granulomatous chronic inflammation by histopathology, which indicated that the lacrimal gland may be an inflammatory target and is affected by systemic inflammation in AOSD.

Adult-Onset Still's Disease following Coronavirus 2 (SARS-CoV-2) Vaccination: A Case Report

In recent years, during the ravages of COVID-19, a variety of vaccines have been developed and are now on the market. However, although these new vaccines have undergone various trials, there are still many unknown side effects. We report a case of a 30-year-old woman who presented with general weakness, sore throat, generalized skin rashes, symmetrical arthralgia, and persistent fever of up to 40 °C with onset 16 days after receiving the Moderna COVID-19 vaccine. Adult-onset Still's disease (AOSD) was diagnosed according to Yamaguchi's criteria after excluding the feasibility of infectious diseases, autoimmune diseases, and malignancies. In particular, her responses to glucocorticoids and naproxen were significant and inversely proportional to her use of empirical antibiotics in the initial stage of treatment. We studied some similar cases of AOSD, which also considered the adverse effects of COVID-19 vaccination and suggested the immunogenicity and possibility of inflammatory responses related to COVID-19 vaccination.

New insights on multigenic autoinflammatory diseases

Autoinflammatory diseases are disorders of the innate immune system, which can be either monogenic due to a specific genetic mutation or complex multigenic due to the involvement of multiple genes. The aim of this review is to explore and summarize the recent advances in pathogenesis, diagnosis, and management of genetically complex autoinflammatory diseases, such as Schnitzler's syndrome; adult-onset Still's disease; synovitis, acne, pustulosis, hyperostosis, osteitis syndrome/chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis; Adamantiades-Behçet's disease; Yao syndrome; and periodic fever with aphthous stomatitis, pharyngitis, and adenitis syndrome. The PubMed database was screened for relevant articles using free text words and specific search strings. The search was limited to English-language articles, reporting the results of studies in humans, published through March 2021. Evidence from literature suggest that these rare multigenic autoinflammatory diseases can present with different clinical features and the diagnosis of these diseases can be challenging due to a combination of nonspecific manifestations that can be seen in a variety of other conditions. Diagnostic delays and disease complications may occur due to low disease awareness and the lack of pathognomonic markers. The pathogeneses of these diseases are complex and in some cases precise pathogenesis is not clearly understood. Conventional treatments are commonly used for the management of these conditions, but biologics have shown promising results. Biologics targeting proinflammatory cytokines including IL-1, IL-6, TNF-α, IL-17A and IL-18 have been shown to ameliorate signs and symptoms of different multigenic autoinflammatory diseases.

Evaluation of Glycosylated Ferritin in Adult-Onset Still's Disease and Differential Diagnoses

Glycosylated ferritin (GF) has been reported as a good diagnostic biomarker for adult-onset Still’s disease (AOSD), but only a few studies have validated its performance. We performed a retrospective study of all adult patients with at least one GF measurement over a 2-year period in one hospital laboratory. The diagnosis of AOSD was based on the expert opinion of the treating physician and validated by two independent investigators. Patients’ characteristics, disease activity, and outcome were recorded and compared. Twenty-eight AOSD and 203 controls were identified. Compared to controls, the mean GF was significantly lower (22.3% vs. 39.3, p < 0.001) in AOSD patients. GF had a high diagnostic accuracy for AOSD, independent of disease activity or total serum ferritin (AUC: 0.674 to 0.915). The GF optimal cut-off value for AOSD diagnosis was 16%, yielding a specificity of 89% and a sensitivity of 63%. We propose a modified diagnostic score for AOSD, based on Fautrel’s criteria but with a GF threshold of 16% that provides greater specificity and increases the positive predictive value by nearly 5 points. GF is useful for ruling out differential diagnoses and as an appropriate classification criterion for use in AOSD clinical trials.

The hyper-expression of NLRP4 characterizes the occurrence of macrophage activation syndrome assessing STING pathway in adult-onset Still's disease

To assess stimulator of interferon genes (STING) pathway in patients with adult-onset Still's disease (AOSD) who were complicated or not by macrophage activation syndrome (MAS), evaluating peripheral blood mononuclear cells (PBMCs), and synovial tissues. The relative mRNA expression of key molecules of the STING pathway (i.e. CGAS, NLRP4, PKDC, STING1, XRCC5, and XRCC6) and interferon (IFN)-γ was assessed in PBMCs obtained from patients with AOSD, who were complicated or not by MAS, and healthy controls (HCs). A bulky RNA sequencing was performed in synovial tissues from two patients with AOSD. Finally, the ability of heavy ferritin subunit (FeH) to induce the expression of NLRP4 was evaluated in cultured macrophages. Twenty patients with AOSD were analysed. Out of them, seven patients were complicated by MAS. Assessing mRNA relative expression in PBMCs, STING1, NLRP4, XRCC6, and IFN-γ were significantly expressed in AOSD than HCs. The mRNA relative expression of CGAS, PKDC, and XRCC5 did not differ between patients and HCs. Furthermore, NLRP4 and IFN-γ resulted to be significantly increased in patients with AOSD complicated by MAS than others. By RNA-sequencing analysis, we observed that Nlrp4 gene was significantly up-regulated in patients with AOSD. Following the stimulation with FeH, an increased expression of NLRP4 was observed in cultured macrophages. In conclusion, an increased expression of some key molecules of STING pathway characterized patients with AOSD. In addition, our results suggested that a hyper-activity of NLRP4 may be observed in patients with MAS. Furthermore, FeH increased the expression of NLRP4 in cultured macrophages.

Disparities in the prevalence of clinical features between systemic juvenile idiopathic arthritis and adult-onset Still's disease

OBJECTIVE

To compare clinical features and treatments of patients with systemic juvenile idiopathic arthritis (sIJA) and adult-onset Still's disease (AOSD).

METHODS

The clinical charts of consecutive patients with sJIA by International League of Association of Rheumatology criteria or AOSD by Yamaguchi criteria were reviewed. Patients were seen at a large paediatric rheumatology referral centre or at 10 adult rheumatology academic centres. Data collected included clinical manifestations, inflammation biomarkers, systemic score, macrophage activation syndrome (MAS), parenchymal lung disease, disease course, disability, death, and medications administered.

RESULTS

166 patients (median age at diagnosis 5 years) with sJIA and 194 patients with AOSD (median age at diagnosis 41 years) were included. The frequency of fever, rash, arthralgia, abdominal pain, MAS, parenchymal lung disease, and increased acute phase reactants and ferritin were comparable between the two cohorts. Patients with sJIA had a higher prevalence of arthritis, whereas patients with AOSD had experienced more frequently leucocytosis and extra-articular organ involvement. Patients with AOSD were given more commonly low-dose corticosteroids, whereas biologic DMARDs were administered first-line more frequently in patients with sJIA.

CONCLUSION

We found remarkable disparities in the prevalence of clinical manifestations between the two illnesses, which may partly depend on their classification by different criteria.

Case Report: A Rare Case of Elderly-Onset Adult-Onset Still's Disease in a Patient With Systemic Lupus Erythematosus

The rare systemic inflammatory disorder 'adult-onset Still's disease (AOSD)' is characterized by recurrent fever, evanescent rash, arthralgia, and leukocytosis with neutrophilia. The Yamaguchi criteria are widely used to diagnose AOSD; these criteria can be used for diagnosis after a wide range of infectious, rheumatic, and neoplastic diseases have been excluded. AOSD generally does not overlap with other rheumatic diseases. We present the rare case of an 80-year-old Japanese woman who presented with arthralgia, fever, and skin rash during treatment for systemic lupus erythematosus (SLE), which was finally diagnosed as an overlap of AOSD. Blood tests revealed leukocytosis with neutrophilia, high C-reactive protein (CRP), and liver dysfunction. Her anti-ds-DNA antibody titer and serum complement titer were at the same level as before and remained stable. We suspected AOSD based on the high serum ferritin level but hesitated to diagnose AOSD because of the patient's SLE history. We measured serum interleukin (IL)-18; it was extremely high at 161,221 pg/mL, which was strongly suggestive of AOSD. We thus diagnosed AOSD complicated during the course of treatment for SLE. The patient's arthralgia and high CRP level persisted after we increased her oral prednisolone dose and added oral methotrexate, but her symptoms eventually improved with the addition of intravenous tocilizumab. We note that the presence of autoantibodies or other rheumatic diseases cannot be absolutely ruled out in the diagnosis of AOSD. Although high serum IL-18 levels are not specific for AOSD, the measurement of serum IL-18 may aid in the diagnosis of AOSD in similar rare cases.

The Role of Interleukin 18/Interleukin 18-Binding Protein in Adult-Onset Still's Disease and Systemic Juvenile Idiopathic Arthritis

Interleukin 18 (IL-18) is a pro-inflammatory cytokine of the IL-1 family, whose activity is tightly controlled at the level of production, as well as signalization. Notably, it is buffered by its natural inhibitor, IL-18 binding protein (IL-18BP), which is massively present in circulation in normal and in most pathological conditions, thus preventing harmful pro-inflammatory systemic effects of IL-18. IL-18 has long been considered to be involved in the pathophysiology of various inflammatory diseases. However, a first clinical trial using recombinant IL-18BP for the treatment of rheumatoid arthritis and psoriasis gave disappointing results. Direct measurements of unbound, bioactive, free form of circulating IL-18 demonstrated that IL-18 was more specifically involved in adult-onset Still’s disease (AOSD) and systemic juvenile idiopathic arthritis (sJIA) but also in their most severe complication, macrophage activation syndrome (MAS). More importantly, administration of recombinant IL-18BP to patients with AOSD, and sJIA with MAS, showed promising results. This review summarizes available data regarding IL-18 and IL-18BP in AOSD and sJIA in mouse models and humans and shows the importance of IL-18/IL-18BP imbalance in these conditions, leading to the conclusion that IL-18, particularly free IL-18, may be a useful biomarker in these diseases and an interesting therapeutic target.

Interluekin-6 inhibitors for the treatment of adult-onset Still's disease

Adult-onset Still's disease is a systemic inflammatory disease characterized by high spiking fever, arthritis, evanescent skin rash, leukocytosis, and hyperferritinemia. The pathogenesis of adult-onset Still's disease has not been fully understood yet; however, multiple proinflammatory cytokines, such as IL-1β and IL-6, play important roles in the development of adult-onset Still's disease. IL-6 is a multifunctional cytokine that accelerates the differentiation of macrophages and cytotoxic T-cells and chemotaxis of neutrophils and macrophages. Serum concentrations of IL-6 well correlate with disease activity of adult-onset Still's disease, and blockade of IL-6 has been proven to be effective in active adult-onset Still's disease. This review will focus on the recent understanding of the role of proinflammatory cytokines of adult-onset Still's disease and the efficacy of IL-6 inhibitors for the treatment of adult-onset Still's disease.

Detection and Prediction of Macrophage Activation Syndrome in Still's Disease

Distinguishing between macrophage activation syndrome (MAS) and a simple flare of Still’s disease (SD) may be challenging. We sought to clarify the clinical features and outcome of MAS in SD and to explore predictive factors of MAS development. Demographic and clinical data, treatments, and outcomes were recorded in a cohort of 206 SD patients. SD patients with and without MAS were compared. To explore predictive factors for the development of MAS, patients were compared at the time of SD diagnosis. Twenty (9.7%) patients experienced MAS, which was inaugural in 12 cases. Patients with MAS were more likely to have hepatomegaly (OR, 3.71; 95% CI, 1.14–11.2; p = 0.03) and neurological symptoms (OR, 4.43; 95% CI, 1.08–15.3; p = 0.04) than patients without MAS. Cytopenias, abnormal liver tests, and coagulation disorders were significantly more frequent in patients with MAS; lactate dehydrogenase and serum ferritin levels were significantly higher. An optimized threshold of 3500 μg/L for serum ferritin yielded a sensitivity (Se) of 85% and a negative predictive value (NPV) of 97% for identifying patients with/without MAS. Survival analysis showed that a high ferritin level at the time of SD diagnosis was predictive of MAS development (p < 0.001). Specific factors, including neurological symptoms, cytopenias, elevated LDH, and coagulopathy, may contribute to the early detection of MAS. Extreme hyperferritinemia at the onset of SD is a prognostic factor for the development of MAS.

Adult-Onset Still's Disease Complicated by Immunoglobulin A Vasculitis and anti-CCP Antibody-Positive Arthritis

A 38-year-old male was admitted to our hospital for arthralgia, fever, skin rash, and purpura. He was diagnosed as having adult-onset Still's disease (AOSD) based on Yamaguchi's criteria. Skin biopsy revealed immunoglobulin A (IgA) vasculitis. He was also found to have anti-cyclic citrullinated peptide (CCP) antibody-positive inflammatory arthritis on a shoulder joint, however he did not fulfill classification criteria for rheumatoid arthritis. Elevated serum cytokine such as serum IL-18 supported the diagnosis of AOSD. His symptoms improved with 40 mg of prednisolone plus cyclosporin A (200 mg/day). Two years after hospitalization, AOSD was relapsed with pleurisy and hyperferritinemia. Finally, he was diagnosed with multicyclic systemic type of AOSD complicated by IgA vasculitis and seropositivity of anti-CCP antibody. Clinicians need to consider the complication of multiple rheumatic diseases, even if the disease-specific autoantibody is positive.

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.

An Update on the Pathogenic Role of Neutrophils in Systemic Juvenile Idiopathic Arthritis and Adult-Onset Still's Disease

Neutrophils are innate immune phagocytes that play a key role in immune defense against invading pathogens. The main offensive mechanisms of neutrophils are the phagocytosis of pathogens, release of granules, and production of cytokines. The formation of neutrophil extracellular traps (NETs) has been described as a novel defense mechanism in the literature. NETs are a network of fibers assembled from chromatin deoxyribonucleic acid, histones, and neutrophil granule proteins that have the ability to kill pathogens, while they can also cause toxic effects in hosts. Activated neutrophils with NET formation stimulate autoimmune responses related to a wide range of inflammatory autoimmune diseases by exposing autoantigens in susceptible individuals. The association between increased NET formation and autoimmunity was first reported in antineutrophil cytoplasmic antibody-related vasculitis, and the role of NETs in various diseases, including systemic lupus erythematosus, rheumatoid arthritis, and psoriasis, has since been elucidated in research. Herein, we discuss the mechanistic role of neutrophils, including NETs, in the pathogenesis of systemic juvenile idiopathic arthritis (SJIA) and adult-onset Still’s disease (AOSD), and provide their clinical values as biomarkers for monitoring and prognosis.

USAID Associated with Myeloid Neoplasm and VEXAS Syndrome: Two Differential Diagnoses of Suspected Adult Onset Still's Disease in Elderly Patients

Background: Patients with solid cancers and hematopoietic malignancy can experience systemic symptoms compatible with adult-onset Still’s disease (AOSD). The newly described VEXAS, associated with somatic UBA1 mutations, exhibits an overlap of clinical and/or biological pictures with auto inflammatory signs and myelodysplastic syndrome (MDS). Objectives: To describe a cohort of patients with signs of undifferentiated systemic autoinflammatory disorder (USAID) concordant with AOSD and MDS/chronic myelomonocytic leukemia (CMML) and the prevalence of VEXAS proposed management and outcome. Methods: A French multicenter retrospective study from the MINHEMON study group also used for other published works with the support of multidisciplinary and complementary networks of physicians and a control group of 104 MDS/CMML. Results: Twenty-six patients were included with a median age at first signs of USAID of 70.5 years with male predominance (4:1). Five patients met the criteria for confirmed AOSD. The most frequent subtypes were MDS with a blast excess (31%) and MDS with multilineage dysplasia (18%). Seven patients presented with acute myeloid leukemia and twelve died during a median follow-up of 2.5 years. Six out of 18 tested patients displayed a somatic UBA1 mutation concordant with VEXAS, including one woman. High-dose corticosteroids led to a response in 13/16 cases and targeted biological therapy alone or in association in 10/12 patients (anakinra, tocilizumab, and infliximab). Azacytidine resulted in complete or partial response in systemic symptoms for 10/12 (83%) patients including 3 VEXAS. Conclusions: Systemic form of VEXAS syndrome can mimic AOSD. The suspicion of USAID or AOSD in older males with atypia should prompt an evaluation of underlying MDS and assessment of somatic UBA1 mutation.

Clinical Characteristics of Japanese Patients with Elderly-Onset Adult-Onset Still's Disease

The aim of this study was to compare the characteristics of Japanese patients with elderly-onset Adult-onset Still's disease (AOSD) and those with younger-onset AOSD. Patients were classified into elderly-onset (≥ 65 years, n = 20) and younger-onset (< 65 years, n = 62) groups according to age at AOSD diagnosis. Analyses included the comparison of clinical features, treatments, and Pouchot and modified Pouchot (mPouchot) scores between the two groups. The frequencies of sore throat, lymphadenopathy, and splenomegaly were significantly lower in the elderly-onset group than in the younger-onset group (30.5% vs. 80.6%, p = 0.0004; 15.0% vs. 54.8%, p = 0.0019; 30.0% vs. 61.3%, p = 0.0203; respectively). There were no significant differences in the frequencies of complications, such as macrophage activation syndrome and disseminated intravenous coagulation, between the patients with elderly-onset or younger-onset AOSD. Serum ferritin levels were higher in the elderly-onset group than in the younger-onset group, albeit without statistical significance (median, 9,423 vs. 4,164 ng/mL, p = 0.1727). Pouchot score was lower in the elderly-onset group than in the younger-onset group (median score, 5.5 vs. 4.0, p = 0.0008); however, there was no significant difference in the mPouchot score between the two groups. Our analyses revealed that elderly-onset AOSD was associated with certain characteristics that were distinct from those of younger-onset AOSD and that the disease severity in patients with elderly-onset AOSD, determined by Pouchot score at the time of AOSD diagnosis, was similar to or less than that in patients with younger-onset AOSD.

Usefulness of Interleukin-18 as a Diagnostic Biomarker to Differentiate Adult-Onset Still's Disease With/Without Macrophage Activation Syndrome From Other Secondary Hemophagocytic Lymphohistiocytosis in Adults

Background

Interleukin (IL)-18 is markedly elevated in systemic inflammatory diseases that cause the ‘cytokine storm’ such as adult-onset Still’s disease (AOSD) and hemophagocytic lymphohistiocytosis (HLH). The differences in IL-18 between AOSD and HLH, especially in adults, is uncertain. Macrophage activation syndrome (MAS), a form of secondary HLH, is often difficult to differentiate cases of AOSD that include MAS from other secondary HLH. In this case-control study, we investigated whether serum IL-18 levels could be a useful biomarker for the differential diagnosis of AOSD with or without MAS (AOSD group) and other secondary HLH in adults (adult HLH group).

Patients and Methods

We enrolled 46 patients diagnosed with AOSD including 9 patients with MAS and 31 patients in the adult HLH group, which excluded AOSD-associated MAS. The clinical features and laboratory data were compared between the AOSD and adult HLH groups. In addition, we subdivided the AOSD group (with or without MAS) and the adult HLH group (whether lymphoma-associated or not) and compared the four groups. A logistic regression analysis was used to identify factors with high efficacy in differentiating the two groups, followed by a receiver operating characteristic (ROC) curve analysis to evaluate the differential diagnostic ability of IL-18. We analyzed the correlation between IL-18 and various laboratory parameters in the AOSD group.

Results

Serum IL-18 levels of patients in the AOSD groups were significantly higher than those of the adult HLH groups, and were closely correlated with ferritin, soluble interleukin-2 receptor (sIL-2R), and other laboratory data. Univariate and multivariate logistic regression analyses revealed that IL-18, sIL-2R, and ‘arthralgia or arthritis’ are independent factors useful in the differential diagnosis of AOSD from adult HLH. In the differential diagnosis of both groups, the area under the curve obtained from the ROC curve of IL-18 with a cutoff value of 18,550 pg/mL was 0.91 (95% confidence interval 0.83–1.00; sensitivity 90.3%, specificity 93.5%), and the differential diagnosis ability of IL-18 was superior to that of other laboratory data.

Conclusions

IL-18 could be a useful biomarker for the differential diagnosis of AOSD and adult HLH.

Anaphylaxis to tocilizumab in patients with rheumatic disease

Background: Anaphylaxis to tocilizumab has been reported anecdotally. Therefore, we evaluated the incidence of anaphylaxis in patients starting tocilizumab. Materials & methods: This retrospective study included patients with rheumatic disease who were administered tocilizumab from 2013 to 2020. The incidence of anaphylaxis was examined during the first 6 months. Results: During follow-up, four of 171 patients developed anaphylaxis within the third course of infusions. The incidence of anaphylaxis to tocilizumab was higher in patients with adult-onset Still's disease (AOSD) than in those with other rheumatic disease (21.4% in AOSD vs 0.7% in rheumatoid arthritis vs 0% in Takayasu arteritis). Conclusions: When we consider tocilizumab treatment, especially in AOSD, we should keep in mind that intensive monitoring for anaphylaxis is necessary.

Still's Disease Mortality Trends in France, 1979-2016: A Multiple-Cause-of-Death Study

Still’s disease (SD) is often considered a benign disease, with low mortality rates. However, few studies have investigated SD mortality and its causes and most of these have been single-center cohort studies. We sought to examine mortality rates and causes of death among French decedents with SD. We performed a multiple-cause-of-death analysis on data collected between 1979 and 2016 by the French Epidemiological Center for the Medical Causes of Death. SD-related mortality rates were calculated and compared with the general population (observed/expected ratios, O/E). A total of 289 death certificates mentioned SD as the underlying cause of death (UCD) (n = 154) or as a non-underlying causes of death (NUCD) (n = 135). Over the study period, the mean age at death was 55.3 years (vs. 75.5 years in the general population), with differences depending on the period analyzed. The age-standardized mortality rate was 0.13/million person-years and was not different between men and women. When SD was the UCD, the most frequent associated causes were cardiovascular diseases (n = 29, 18.8%), infections (n = 25, 16.2%), and blood disorders (n = 11, 7.1%), including six cases (54%) with macrophage activation syndrome. As compared to the general population, SD decedents aged <45 years were more likely to die from a cardiovascular event (O/E = 3.41, p < 0.01); decedents at all ages were more likely to die from infection (O/E = 7.96–13.02, p < 0.001).

Distinct Effects of Interleukin-1β Inhibition upon Cytokine Profile in Patients with Adult-Onset Still's Disease and Active Articular Manifestation Responding to Canakinumab

Adult-onset Still’s disease (AOSD) is a systemic auto-inflammatory disease characterized by the presence of immunologically mediated inflammation and deficient resolution of inflammation. Canakinumab is an approved IL-1β inhibitor in the treatment of AOSD with a balanced efficacy and safety profile. Since inflammatory cytokines play a major role in the pathogenesis of AOSD, we investigated the effects of canakinumab on the cytokine profile of AOSD patients from a randomized controlled trial. Multiplex analysis and ELISA were used to test the concentrations of several cytokines at three time points—week 0 (baseline), week 1 and week 4—in two patient groups—placebo and canakinumab. Two-way repeated-measures analysis of variance revealed a significant temporal effect on the concentrations of MRP 8/14, S100A12, IL-6 and IL-18 with a significant decrease at week 4 in the canakinumab group exclusively. Comparing responders with non-responders to canakinumab showed a significant decrease in MRP 8/14, IL-1RA, IL-18 and IL-6 in responders at week 4, while S100A12 levels decreased significantly in responders and non-responders. In summary, canakinumab showed a striking effect on the cytokine profile in patients with AOSD, exhibiting a clear association with clinical response.

Adult-onset Still's disease or systemic-onset juvenile idiopathic arthritis and spondyloarthritis: overlapping syndrome or phenotype shift?

OBJECTIVES

Systemic-onset juvenile idiopathic arthritis (SJIA) and adult-onset Still's disease (AOSD) are the same sporadic systemic auto-inflammatory disease. Spondyloarthritis (SpA) is a group of inflammatory non-autoimmune disorders. We report the observations of eight patients with SJIA/AOSD who also presented features of SpA during their disease evolution and estimate the prevalence of SpA in SJIA/AOSD.

METHODS

This was a retrospective national survey of the departments of paediatric and adult rheumatology and internal medicine. To be included, SJIA patients had to fulfil the ILAR criteria, AOSD patients the Yamaguchi or Fautrel criteria, and all patients the ASAS classification criteria for axial or peripheral SpA, ESSG criteria for spondyloarthropathy or CASPAR criteria for psoriatic arthritis. The data were collected with a standardized form.

RESULTS

Eight patients (five adults) were identified in one paediatric and two adult departments. In all but one patient, SpA manifestations occurred several years after SJIA/AOSD onset (mean delay 6.2 ± 3.8 years). Two patients had peripheral and three axial SpA, and four later exhibited psoriatic arthritis and one SAPHO syndrome. The prevalence of SpA in an adult cohort of 76 patients with AOSD was 6.58% (95% CI [2.17-14.69]), greater than the prevalence of SpA in the French general population (0.3%, 95%CI [0.17-0.46]). The prevalence of SpA in an SJIA cohort of 30 patients was 10% (95%CI [2.11-26.53]), more than that reported in the general population of industrialized countries, estimated at 0.016% to 0.15%.

CONCLUSION

Whilst the temporal disassociation between SpA and AOSD in most cases might suggest a coincidental finding, our work raises the possibility of an SpA AOSD spectrum overlap that needs further study.

Adult-onset Still's disease with neurological involvement: a single-centre report

OBJECTIVES

Adult-onset Still's disease (AOSD) is a multifactorial systemic autoinflammatory disease. Neurological damage has been rarely reported in AOSD. We aimed to characterize the clinical features of AOSD patients with neurological involvement.

METHODS

A total of 187 AOSD patients were admitted to Peking Union Medical College Hospital from January 2015 to August 2019. The complete medical records were reviewed in this retrospective study. Clinical features of 14 AOSD patients with neurological involvement were collected and compared with those without.

RESULTS

The prevalence of neurological involvement in AOSD inpatients was 7.5%. The median disease duration was 4.5 months, with a range of 1-15 months. The frequent symptoms were fever [14 (100%)], rash [13 (92.9%)], liver dysfunction [11 (78.6%)], arthralgia/arthritis [10 (71.4%)] and lymphadenopathy [10 (71.4%)]. Four (28.6%) patients had macrophage activation syndrome (MAS). Aseptic meningitis was the most common presentation (64.3%) when the nervous system was involved. Other rare manifestations included cranial nerve palsy, encephalitis and cerebral infarction. The rate of MAS, serum levels of lactate dehydrogenase and ferritin were significantly higher in AOSD patients with neurological involvement than in those without. All patients received high-dose corticosteroid therapy and immunosuppressive agents and two were given tocilizumab. Clinical remission was achieved in all 14 AOSD patients with neurological involvement.

CONCLUSION

Neurological involvement, particularly aseptic meningitis, is not a rare complication of AOSD. It is frequently complicated by MAS. There may be a potential relationship between the neurological damage of AOSD and MAS.

Current and emerging biological therapy in adult-onset Still's disease

Adult-onset Still's disease (AOSD) is a rare, but characteristic non-familial, multi-genic systemic auto-inflammatory disorder, characterized by high spiking fever, salmon-like evanescent skin rash, polyarthritis, sore throat, hyperferritinemia and leucocytosis. The hallmark of AOSD is a cytokine storm triggered by dysregulation of inflammation. Nowadays, with advances in anti-cytokine biologic agents, the treatment of AOSD is no longer limited to NSAIDs, glucocorticoids or conventional synthetic DMARDs. In this review, we focussed on the roles of these cytokines in the pathogenesis of AOSD and summarized the current and emerging biological therapy.

Elevated serum gasdermin D N-terminal implicates monocyte and macrophage pyroptosis in adult-onset Still's disease

OBJECTIVES

Elevation of serum IL-18 in adult-onset Still's disease (AOSD) and systemic JIA (sJIA) suggests the role of the inflammasome in these diseases. Gasdermin D is a pore-forming protein playing central roles in inflammasome-mediated inflammation, but its role in rheumatic disease is unknown. We aimed to elucidate the auto-inflammatory mechanisms in AOSD and sJIA.

METHODS

Patients with AOSD, sJIA, hemophagocytic lymphohistiocytosis (HLH) and Behçet's disease followed at Yokohama City University (YCU), or US National Institutes of Health (NIH) were included in the study. Disease activity was evaluated by the modified Pouchot score. Ferritin and N-terminal gasdermin D levels in serum and culture supernatant were measured by ELISA. Primary monocytes (Mo) were stimulated with GM-CSF or M-CSF and differentiated into M1 macrophages (Mφ) or M2Mφ, respectively. The number of Mo/Mφ and their viability were monitored over time.

RESULTS

Patients with active AOSD and sJIA had increased levels of serum gasdermin D N-terminal, which correlated with serum ferritin and IL-18 levels. Mo-derived Mφ from active AOSD patients showed reduced cell viability and increased cell death. The number of cultured Mφ cells on day nine was negatively correlated with the serum ferritin and gasdermin D levels. Higher ferritin and gasdermin D levels were observed in the M1Mφ culture supernatant of active AOSD patients. Gasdermin D inhibitors reduced the pyroptosis-mediated ferritin release in Mo.

CONCLUSION

Elevation of serum gasdermin D N-terminal provides evidence for inflammasome activation triggering gasdermin D-mediated Mo and Mφ pyroptosis in AOSD and possibly sJIA.

Circulating regulatory T cells in adult-onset Still's disease: Focusing on their plasticity and stability

We investigated the characteristics of regulatory T cells in adult-onset Still's disease (AOSD) with a focus on their plasticity, stability and relationship to disease severity. The proportion of circulating CD4⁺ CD25⁺ forkhead box protein 3 (FoxP3⁺ ) cells (T_regs ) and intracellular expression of effector cytokines, including interferon (IFN)-γ, interleukin (IL)-17 and IL-4, was analysed in 27 untreated patients with AOSD (acute AOSD), 11 of the 27 patients after remission and 16 healthy controls (HC) using flow cytometry. The suppressive ability of T_regs was also evaluated. Regression analyses of the results were performed. The proportion of T_regs was significantly lower in patients with acute AOSD than in the HC. The expression levels of IFN-γ, IL-17 and IL-4 in T_regs were significantly increased in patients with acute AOSD. IFN-γ and IL-4 expression levels were inversely correlated with the proportion of T_regs and positively correlated with serum ferritin levels. Decreased expression of FoxP3 in CD4⁺ CD25⁺ cells, which was correlated with increased expression of IL-17, and impaired suppressive function were observed in T_regs in acute AOSD. However, these aberrant findings in T_regs , including the reduced circulating proportion and functional ability and altered intracellular expression levels of cytokines and FoxP3, were significantly improved after remission. In acute AOSD, T_regs show plastic changes, including effector cytokine production and reductions in their proportion and functional activity. IFN-γ and IL-4 expression levels in T_regs may be associated with disease severity. Also, down-regulation of FoxP3 may be related to IL-17 expression in T_regs . Importantly, the stability of T_regs can be restored in remission.

Interleukin-6 inhibition: a therapeutic strategy for the management of adult-onset Still's disease

Introduction:Patients with adult-onset Still's disease have markedly elevated serum levels of proinflammatory cytokines, such as IL-1β, IL-6, and IL-18, suggesting the potential of these molecules as therapeutic targets. IL-6 accelerates macrophage and cytotoxic T-cell differentiation and neutrophil and macrophage chemotaxis and is one of the most important cytokines in the pathogenesis of adult-onset Still's disease.Areas covered:The review summarizes the importance of IL-6 in the pathogenesis of adult-onset Still's disease and clinical aspects of IL-6 inhibition from retrospective and prospective studies.Expert opinion:Adult-onset Still's disease is a systemic inflammatory disease of unknown etiology and characterized by elevated various proinflammatory cytokines. In particular, serum concentrations of IL-6 is significantly high in patients with active adult-onset Still's disease, and many case reports, cohort studies and one randomized, placebo-controlled trail have shown the efficacy of IL-6 blockade in patients with adult-onset Still's disease who were refractory to glucocorticoids and other immunosuppressive treatments. IL-6 inhibition is effective for both systemic and joint manifestations with arthritis improving slowly. There is still a concern over the triggering of macrophage activation syndrome; however, the IL-6 inhibition strategy has introduced better management of adult-onset Still's disease.

Clinical Phenotypes of Adult-Onset Still's Disease: New Insights from Pathophysiology and Literature Findings

Adult-onset Still's disease (AOSD) is a non-familial, polygenic systemic autoinflammatory disorder. It is traditionally characterized by four cardinal manifestations-spiking fever, an evanescent salmon-pink maculopapular rash, arthralgia or arthritis and a white-blood-cell count (WBC) ≥ 10,000/mm³, mainly neutrophilic polymorphonuclear cells (PMNs)-but many other manifestations and complications can be associated, making clinical expression very heterogeneous and diagnosis sometimes difficult. The AOSD course can be diverse and is currently impossible to predict. Several clinical phenotypes have been described, either on the basis of the evolution of symptoms over time (monocyclic, polycyclic and chronic evolution) or according to dominant clinical evolution (systemic and arthritis subtypes). However, these patterns are mainly based on case series and not on robust epidemiological studies. Furthermore, they have mainly been established a long time ago, before the era of the biological treatments. Thus, based on our personal experience and on recent advances in the understanding of disease pathogenesis, it appears interesting to reshuffle AOSD phenotypes, emphasizing the continuum between AOSD profiles and other systemic autoinflammatory disorders, eventually proposing a research agenda.

The Association of ATG16L1 Variations with Clinical Phenotypes of Adult-Onset Still's Disease

Adult-onset Still’s disease (AOSD) is a rare autoinflammatory disease, which has elevated autophagosome levels regulated by autophagy-related gene (ATG) expression. We investigated the associations of ATG polymorphisms with AOSD susceptibility, clinical manifestations, and disease course. The six-candidate single-nucleotide polymorphisms (SNPs) involved in autophagy were genotyped using direct sequencing on samples from 129 AOSD patients and 129 healthy participants. The differentially expressed gene products were quantified using PCR and ELISA. Significant linkage disequilibrium was noted in three SNPs of autophagy-related 16-like 1 (ATG16L1) gene (rs10210302, rs2241880, and rs1045100). Although the AA/CC/TT haplotype of ATG16L1 was not associated with the susceptibility of our AOSD patients compared with other haplotypes, those carrying this haplotype had lower mRNA expression levels of LC3-II, reflecting by autophagosome formation (p = 0.026). Patients carrying AA/CC/TT haplotype also have a significantly higher proportion of skin rash and a lower proportion of arthritis compared with other haplotypes. The AA/CC/TT haplotype was significantly associated with systemic pattern (odds ratio, 3.25; 95% confidence interval, 1.15–9.14; p = 0.026). In summary, the AA/CC/TT haplotype encoded lower levels of autophagosome formation and was associated with a higher proportion of skin rash and systemic pattern of AOSD compared with other haplotypes.

Characteristics and Clinical Value of 18F-FDG PET/CT in the Management of Adult-Onset Still's Disease: 35 Cases

While the diagnosis of adult-onset Still’s disease (AOSD) involves the exclusion of differential diagnoses, the characteristics and value of 18F-Fluorodeoxyglucose (18F-FDG) Positron Emission Tomography coupled with CT (PET/CT) in the management of AOSD remain poorly known. Our retrospective study included patients from four centers, fulfilling Yamaguchi or Fautrel criteria, who underwent a PET/CT during an active AOSD. Thirty-five patients were included. At the time of PET/CT, the Yamaguchi criteria were met in 23 of 29 evaluable cases. PET/CT showed bone marrow (74.3%), lymph node (74.3%), and splenic (48.6%) FDG uptake. Despite arthralgia or arthritis in most patients, joints were rarely the sites of 18F-FDG accumulation. The spatial distribution of 18F-FDG uptake was nonspecific, and its intensity could be similar to malignant disease. Lymph node or bone marrow biopsy was performed after PET/CT in 20 patients (57.1%). The intensity of bone marrow; splenic and lymph node hypermetabolism appeared to be correlated with disease activity. Abnormal PET/CT in the cervical lymph nodes and age ≥ 60 years seemed to be predictive factors for monocyclic evolution. The clinical value of PET/CT is not in direct diagnosis; but as an aid in excluding differential diagnoses by searching for their scintigraphic features and guiding biopsy.

Adult-Onset Still's Disease Presenting as Macrophage-Activation Syndrome With Critical Illness in the Third Trimester of Pregnancy: A Case Report

Supplemental Digital Content is available in the text.

BACKGROUND:

We report a case of a young woman with adult-onset Still’s disease presenting as macrophage-activation syndrome complicated by shock and respiratory failure during the third trimester of pregnancy.

CASE SUMMARY:

A previously healthy 26-year-old woman at 35 weeks of gestation presented with 1 week of constitutional symptoms and was found to be febrile, tachycardic, and hypotensive. She delivered a healthy neonate by cesarean section. Following delivery, she had worsening hypotension and fevers despite fluid resuscitation and antibiotics, and developed progressive hypoxemia requiring up to 60% Fio₂, with bilateral upper-lobe predominant opacities on chest CT. She also had laboratory derangements including anemia, thrombocytopenia, low fibrinogen, elevated ferritin, and abnormal liver chemistries. After extensive testing to exclude infections, hemolysis, and other pertinent disorders, the development of polyarthralgias and a characteristic rash fulfilled criteria for adult-onset Still’s disease complicated by macrophage-activation syndrome. Her condition improved with immunosuppressive therapy.

CONCLUSION:

To our knowledge, this is the first report of new-onset adult-onset Still’s disease during the third trimester of pregnancy, which presented as macrophage-activation syndrome. In the context of late pregnancy, macrophage-activation syndrome can mimic or raise concern for hemolysis, elevated liver enzymes, and low platelet syndrome and other peripartum disorders. Furthermore, the characteristic articular symptoms of adult-onset Still’s disease may be mild and/or delayed, and pulmonary involvement with severe hypoxemia can occur. Clinicians should consider this diagnosis when evaluating a pregnant patient with unexplained fever and multiorgan dysfunction.

Acute Myocarditis Revealing Adult-Onset Still's Disease

A 34-year-old man presented with fever, palpitations, maculopapular rash, pharyngitis, left cheilitis, and bilateral gonalgia. High-sensitivity troponin I concentration was 4,900 ng/l. Transthoracic echocardiogram revealed reduced global longitudinal strain. Cardiac magnetic resonance imaging showed acute myocarditis. Adult-onset Still’s disease was diagnosed, and treatment with intravenous corticosteroids and tocilizumab was initiated. (Level of Difficulty: Beginner.)

Neutrophil-derived lipocalin-2 in adult-onset Still's disease: a novel biomarker of disease activity and liver damage

OBJECTIVE

Liver damage is a common manifestation and can be life-threatening in adult-onset Still's disease (AOSD), an autoinflammatory disease. The hallmark of AOSD is activation of neutrophils, whose infiltration in liver is suspected to promote tissue injury. Here we aimed to identify a candidate biomarker and to validate its association with liver damage in AOSD.

METHODS

Transcriptome analysis of neutrophils from treatment-naïve active AOSD patients and healthy donors was performed. Lipocalin-2 (LCN2) expression was assessed in neutrophils, plasma and liver biopsies of AOSD. The correlations of LCN2 with different variables and its ability to identify liver damage from AOSD patients were analysed.

RESULTS

LCN2, a novel biomarker in hepatic inflammation, was found to be upregulated in AOSD neutrophils by RNA sequencing and confirmed at the mRNA and protein levels. Plasma levels of LCN2 were significantly higher in AOSD patients than healthy controls, RA and SLE patients. Plasma LCN2 levels were closely correlated with inflammatory markers, systemic score, HScore and cytokines. Moreover, LCN2 levels were increased in active AOSD with liver involvement and independently associated with liver dysfunction. Enhanced expression of LCN2 was detected in liver biopsies from three patients with ongoing liver injury. Furthermore, the area under the curve value of LCN2 for identifying AOSD with liver injury from other liver diseases was 0.9694.

CONCLUSION

Our results reveal that neutrophils-derived LCN2 is higher in plasma and liver tissue in AOSD patients than in healthy controls, and it could serve as a potent biomarker for identifying AOSD with systemic inflammation, especially liver damage caused by hyperinflammation.

The Pathogenic Role of Interferons in the Hyperinflammatory Response on Adult-Onset Still's Disease and Macrophage Activation Syndrome: Paving the Way towards New Therapeutic Targets

Adult-onset Still's disease (AOSD) is a systemic inflammatory disorder of unknown aetiology affecting young adults, which is burdened by life-threatening complications, mostly macrophage activation syndrome (MAS). Interferons (IFNs) are signalling molecules that mediate a variety of biological functions from defence against viral infections, to antitumor and immunomodulatory effects. These molecules have been classified into three major types: IFN I, IFN II, IFN III, presenting specific characteristics and functions. In this work, we reviewed the role of IFNs on AOSD and MAS, focusing on their pathogenic role in promoting the hyperinflammatory response and as new possible therapeutic targets. In fact, both preclinical and clinical observations suggested that these molecules could promote the hyperinflammatory response in MAS during AOSD. Furthermore, the positive results of inhibiting IFN-γ in primary hemophagocytic lymphohistiocytosis may provide a solid rationale to arrange further clinical studies, paving the way for reducing the high mortality rate in MAS during AOSD.

Different Features of Interleukin-37 and Interleukin-18 as Disase Activity Markers of Adult-Onset Still's Disease

The aim of this study was to evaluate the usefulness of serum interleukin (IL)-37 and IL-18 as disease activity markers of adult-onset Still’s disease (AOSD) and to compare their related clinical features. Forty-five patients with a set of high and subsequent low disease activity status of AOSD were enrolled. Modified Pouchot (mPouchot) score and serologic disease activity markers including levels of IL-37 and IL-18 were compared between high and low disease activity status. The relationships between disease activity parameters and differences in levels of cytokines according to each disease manifestation were evaluated in high disease activity status. mPouchot score and all disease activity markers including IL-37 and IL-18 significantly declined after treatment. Though both cytokines positively correlated with mPouchot score, the two did not correlate with each other in high disease activity status. IL-18 positively correlated with ferritin, AST, and LDH while IL-37 correlated better with CRP. The expression level of IL-37 was related to leukocytosis while IL-18 was related to pleuritis, pneumonitis, abnormal LFT, and hyperferritinemia. In addition, patients in the IL-18 dominant group presented with higher LDH levels and required a higher mean corticosteroid dose. In conclusion, IL-37 and IL-18 are disease activity markers reflecting different aspects of AOSD that can complement each other.

Adult-Onset Still's Disease: Clinical Aspects and Therapeutic Approach

Adult-onset Still's disease (AoSD) is a rare systemic autoinflammatory disease characterized by arthritis, spiking fever, skin rash and elevated ferritin levels. The reason behind the nomenclature of this condition is that AoSD shares certain symptoms with Still's disease in children, currently named systemic-onset juvenile idiopathic arthritis. Immune dysregulation plays a central role in AoSD and is characterized by pathogenic involvement of both arms of the immune system. Furthermore, the past two decades have seen a large body of immunological research on cytokines, which has attributed to both a better understanding of AoSD and revolutionary advances in treatment. Additionally, recent studies have introduced a new approach by grouping patients with AoSD into only two phenotypes: one with predominantly systemic features and one with a chronic articular disease course. Diagnosis presupposes an extensive diagnostic workup to rule out infections and malignancies. The severe end of the spectrum of this disease is secondary haemophagocytic lymphohistiocytosis, better known as macrophage activation syndrome. In this review, we discuss current research conducted on the pathogenesis, diagnosis, classification, biomarkers and complications of AoSD, as well as the treatment strategy at each stage of the disease course. We also highlight the similarities and differences between AoSD and systemic-onset juvenile idiopathic arthritis. There is a considerable need for large multicentric prospective trials.

Effectiveness of Profiling Serum IL-18 and Neopterin in Diagnosis of Adult-Onset Still's Disease Complicated by Pulmonary Tuberculosis: A Case Report

Adult-onset Still's Disease (AOSD) is a systemic inflammatory disorder characterized by high fever, skin rashes, and joint pains, and is extremely rare in patients over 80 years of age. An 88-year-old woman was admitted with high fever lasting for > 2 weeks and arthritis of the right knee and bilateral wrists. Further examination revealed that the patient fulfilled the Yamaguchi criteria, the most sensitive and extensively used classification criteria for AOSD. After ruling out other causes and considering a greatly raised serum interleukin-18 (IL-18) level, the patient was diagnosed with AOSD. Before prednisolone therapy, active tuberculosis was excluded using chest computed tomography (CT) and an interferon-gamma release assay (IGRA). After starting the treatment, serum levels of IL-18 and acute-phase reactants were decreased gradually. However, during prednisolone tapering, fever relapsed along with increasing serum acute phase reactant levels. Her serum IL-18 level was decreased but remained at a high level, and the neopterin level was further increased. These findings suggested the onset of another disease, but not AOSD recurrence. A chest CT scan revealed new lung infiltrates. Despite the initial negative IGRA result, cultures and polymerase chain reaction tests of bronchoalveolar lavage and sputum were positive for Mycobacterium tuberculosis. She was placed on a 9-month course of anti-tuberculosis therapy and continued prednisolone tapering. She showed steady improvement and her cytokine profile showed a decrease in the IL-18 and neopterin levels. In conclusion, cytokine profiling is useful in making the diagnosis of AOSD and subsequent pulmonary tuberculosis developed during steroid therapy.

Serum sTREM-1 in adult-onset Still's disease: a novel biomarker of disease activity and a potential predictor of the chronic course

Objectives

Triggering receptor expressed on myeloid cells-1 (TREM-1) is an amplifier of inflammatory signals. Recently, a soluble form of TREM-1 (sTREM-1) was described. This study aimed to investigate the role of serum sTREM-1 in patients with adult-onset Still’s disease (AOSD).

Methods

Serum sTREM-1 levels were detected in 108 AOSD patients, 88 RA patients and 112 healthy controls (HC). The correlations of sTREM-1 with disease activity, clinical characteristics and laboratory parameters in AOSD patients were analysed by the Spearman correlation test. Risk factors for the chronic course of AOSD were evaluated by multivariate logistic regression analysis.

Results

AOSD patients had significantly higher serum sTREM-1 levels than RA patients and HC, and serum sTREM-1 levels were correlated with the systemic score, ferritin, leucocyte count, CRP, IL-1β and IL-6. The elevation in the initial sTREM-1 level by itself could discriminate patients developing the chronic course from patients developing the nonchronic course. Moreover, an elevated sTREM-1 level (> 526.4475 pg/ml) was an independent risk factor for the chronic course in active AOSD patients. Furthermore, interfering with TREM-1 engagement led to reductions in the secretion of pro-inflammatory cytokines, such as IL-1β, IL-6 and TNF-α, in neutrophils and monocytes from active AOSD patients.

Conclusion

Serum sTREM-1 levels are correlated with disease activity, and an elevation in the initial serum sTREM-1 level is a potential predictor of the chronic course in AOSD patients, which currently provides the best predictive model for identifying patients prone to developing the chronic course of AOSD.