Adult-onset Still's disease-pathogenesis, clinical manifestations, and new treatment options

Increased serum caspase-1 in adult-onset Still's disease

BACKGROUND

Caspase-1 is a crucial component in the inflammasome activation cascade. This study evaluated the potential of serum caspase-1 level as an inflammatory biomarker in patients with adult-onset Still's disease (AOSD).

METHODS

The study included 51 consecutive patients diagnosed with AOSD based on the Yamaguchi criteria, 66 patients with rheumatoid arthritis (RA) as disease control, and 36 healthy controls (HCs). Serum caspase-1 concentrations were measured using enzyme-linked immunosorbent assay. The serum 69 cytokine levels were analyzed using a multisuspension cytokine array in patients with AOSD, and a cluster analysis of each cytokine was performed to determine specific molecular networks.

RESULTS

Patients with AOSD had significantly increased serum caspase-1 levels versus patients with RA (p < 0.001) and HCs (p < 0.001). Additionally, serum caspase-1 demonstrated significant positive correlations with AOSD disease activity score (Pouchot score, r = 0.59, p < 0.001) and serum ferritin (r = 0.54, p < 0.001). Furthermore, among patients with AOSD, significant correlations existed between serum caspase-1 and inflammatory cytokines, including interleukin-18. Immunoblot analysis detected the cleaved form of caspase-1 (p20) in the serum of untreated patients with AOSD, not in those from patients with inactive AOSD receiving immunosuppressive treatments.

CONCLUSIONS

Caspase-1 is a useful biomarker for AOSD diagnosis and monitoring. Caspase-1 activation could be correlated with the inflammatory component of AOSD, specifically through proinflammatory cytokine induction via inflammasome activation cascades.

Emergency Mechanical Thrombectomy for Acute Middle Cerebral Artery Occlusion Accompanied by Adult-Onset Still's Disease

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory condition of an unknown etiology. Stroke is a rare complication associated with AOSD; most of these are cerebral infarctions due to the occlusion of small blood vessels. Here, we report the first case of mechanical thrombectomy in a patient with cerebral infarction due to a large vessel occlusion associated with AOSD. A 60-year-old man with no underlying disease was diagnosed with AOSD. Sixteen days after admission, he suddenly lost consciousness and was found to have right hemiplegia and aphasia. Head CT showed early signs of ischemic infarction in the left insular cortex, and head CT angiography demonstrated occlusion in a part of the left middle cerebral artery (MCA). Therefore, we decided that mechanical thrombectomy was an indication of revascularization. We performed mechanical thrombectomy using a Trevo NXT 4 × 28 mm (Stryker, Kalamazoo, USA) and obtained reperfusion of the MCA. The results of the cerebral angiography were indicative of an embolic cerebral infarction, and we investigated the source of the embolism including an insertable cardiac monitor (ICM) (Reveal LINQ, Medtronic, Minneapolis, USA). However, no disease other than AOSD that could be a source of embolism was observed. Therefore, AOSD was assumed to be associated with embolisms. AOSD may cause embolic cerebral infarction and may be indicated for mechanical thrombectomy.

Pregnancy-Associated Onset of Adult-Onset Still's Disease

Objective  This study aims to elucidate the clinical manifestations, diagnostic challenges, and management strategies of adult-onset Still's disease (AOSD) during pregnancy, leveraging a case series overview and a detailed case report from our center. Study Design  A comprehensive review of 21 published case reports on AOSD diagnosed during pregnancy was conducted, alongside a detailed case report of a patient diagnosed and managed at our center. This study emphasizes the importance of recognizing AOSD in pregnant patients, outlines the therapeutic challenges encountered, and discusses the potential complications arising from the disease and its treatment. Results  The onset of AOSD during pregnancy predominantly occurs in the first or second trimester, with a polycyclic disease course observed in most cases. Management primarily involves corticosteroids and immunosuppressive medications, balancing the disease control with potential pregnancy complications. The case report highlights the complex interplay between AOSD, hemophagocytic lymphohistiocytosis, and pregnancy, illustrating a multidisciplinary approach to management that ensured favorable maternal and fetal outcomes despite the significant challenges. Conclusion  AOSD presents unique diagnostic and therapeutic challenges during pregnancy, requiring careful consideration of maternal and fetal health. Early diagnosis, a multidisciplinary approach to care, and judicious use of immunosuppressive therapy are critical for managing AOSD flares and associated complications. Further research is necessary to optimize care for this rare condition in the context of pregnancy.

Refractory Adult-onset Still's Disease Treated with a Combination of Methotrexate and Etanercept

BACKGROUND

Adult-onset Still's disease (AOSD) is a challenging diagnosis because of the variability in clinical presentation and lack of gold-standard diagnostic investigations. Even after diagnosis, the treatment is challenging, especially when the disease is refractory to first-line therapy. Multiple pharmacotherapeutic options exist for refractory AOSD, but treatment failures still occur. Etanercept, a Tumor necrosis factor (TNF)-alpha inhibitor, is one of the options that has been rarely used for refractory AOSD, with various outcomes ranging from no response to complete remission.

CASE PRESENTATION

In this case, we highlight how a previously healthy lady had refractory AOSD to glucocorticoids, methotrexate, and hydroxychloroquine combination therapy. There was no response to interleukin (IL)-1 therapy, which necessitated a switch to a combination of etanercept, low-dose methotrexate, and low-dose glucocorticoids with complete remission for a total of three- -year follow-up.

CONCLUSION

The combination of methotrexate and Etanercept can maintain remission in patients with refractory AOSD.

Multidisciplinary approach to diagnosis and management of fever of unknown origin: A case report

INTRODUCTION

Fever of unknown origin (FUO) poses a diagnostic challenge, often requiring a systematic evaluation to uncover its elusive cause. This case study delves into the presentation of a 42-year-old Chinese male with persistent fever, muscle pain, and a perplexing rash.

PATIENT CONCERNS

The patient's symptoms included a prolonged fever, chills, muscle pain, and throat discomfort, with a history of pulmonary tuberculosis. Initial diagnoses of upper respiratory infection and unspecified infection were followed by antibiotic treatments, yet the fever persisted, accompanied by an exacerbating rash.

DIAGNOSIS

Extensive diagnostic investigations, including laboratory tests, imaging studies, and skin dermoscopy, provided valuable insights. The patient exhibited elevated inflammatory markers, hepatosplenomegaly, lymphadenopathy, and lung nodules. Differential diagnoses included adult-onset Still disease and drug-induced hypersensitivity syndrome.

INTERVENTIONS

The patient received a series of antibiotic treatments, which initially had limited success. Upon considering an autoimmune etiology, corticosteroids were introduced, followed by cyclosporine. The patient exhibited a positive response to this immunosuppressive therapy.

OUTCOMES

Treatment adjustments were made, and the patient responded positively to a combination of corticosteroids and cyclosporine. His fever subsided, and laboratory markers normalized. One month after discharge, the patient showed continued improvement.

CONCLUSION

FUO cases often demand a multidisciplinary approach, considering rare and uncommon diseases. This case underscores the importance of thorough evaluation, collaboration between specialties, and vigilant monitoring of treatment responses. The patient's unique presentation emphasizes the need to consider drug-induced reactions, even when symptoms deviate from typical disease patterns, highlighting the complexities in diagnosing and managing FUO.

Liver involvement in adult-onset Still's disease: our experience in a third level liver unit and review of the literature

Adult-onset Still's Disease (AOSD) is a systemic inflammatory condition, mainly characterized by high spiking fevers, leukocytosis, skin rash, arthralgia and myalgia. Liver involvement is a frequent feature, usually presenting with hepatomegaly and mild liver enzymes abnormalities, which usually normalize after treatment with anti-inflammatory or immunomodulatory drugs given for AOSD. Although uncommon, the onset of severe acute hepatitis and even of life-threatening liver failure is possible and requires a prompt diagnosis and an aggressive therapy and, in some cases, an emergency liver transplantation. The differential diagnosis of the cause of the liver injury can be very challenging in these patients. We reviewed the charts of all consecutive patients admitted for acute hepatitis, between January 2019 and December 2019, to the unit of Gastroenterology and Hepatology, Molinette Hospital, Turin, Italy, searching for episodes AOSD-related. In this period, 21 cases of acute hepatitis were recorded with one among them diagnosed as due to AOSD. The incidence was 5% (1/21). This patient was a woman with a recent diagnosis of AOSD who developed a severe acute seronegative biopsy-proven autoimmune hepatitis. She was successfully treated with high-dose methylprednisolone, with a full and stable recovery from the liver injury. We discussED the incidence, etiology, pathophysiology, diagnosis, and standard of treatment in the clinical management of AOSD with a special attention and a systematic review on the available therapies for severe liver involvement associated with AOSD.

Burden of adult-onset Still's disease: A systematic review of health-related quality of life, utilities, costs and resource use

Adult-onset Still's disease (AOSD) poses a not well estimated burden on patients and healthcare systems. To assess this burden, a systematic review (SR) was undertaken to identify health-related quality of life (HRQoL), utilities, costs and healthcare resource use data. Searches of twelve databases, four conferences, and three key technology assessment and regulatory agency websites were conducted in August 2022. Reference lists of retrieved SRs published since 2017 were also checked. Overall, 16 studies were eligible for inclusion. Eight studies reported HRQoL outcomes, one of which also reported utilities data. Two studies reported direct costs outcomes, and seven reported healthcare resource use data. No indirect costs were identified. A range of outcomes were reported, thus limiting the comparability of results across studies. SF-36 data were impaired in AOSD on most scales, especially those concerning physical activity. Mean SF-36 data were lower across all subscales in patients with active AOSD compared with inactive AOSD. Biologic therapy showed improvements in the SF-36 physical health summary. Utility scores (one study) were significantly lower for AOSD than for healthy controls. Limited direct economic costs data were identified but were substantial where reported. Hospital length of stay ranged from 6.1 to 23.5 days. The SR showed there is a paucity of research reporting the HRQoL and cost burden of AOSD.

The Role of Erythrocyte Sedimentation Rate (ESR) in Myeloproliferative and Lymphoproliferative Diseases: Comparison between DIESSE CUBE 30 TOUCH and Alifax Test 1

(1) Background: The erythrocyte sedimentation rate (ESR) is widely diffused in hematology laboratories to monitor inflammatory statuses, response to therapies (such as antibiotics), and oncologic diseases. However, ESR is not a specific diagnostic marker but needs to be contextualized and compared with clinical and other laboratory findings. This study aimed to investigate the performance of two automated instruments, namely the DIESSE CUBE 30 TOUCH (DIESSE, Siena, Italy) and the Alifax Test 1 (Alifax Srl, Polverara, Italy), in comparison with the gold standard, the Westergren method, in lymphoproliferative and myeloproliferative patients. (2) Methods: 97 EDTA samples were selected from the hematology department of Roma Tor Vergata Hospital and analyzed. Statistical analysis was applied. (3) A good correlation between CUBE 30 TOUCH and the gold standard was observed in the overall sample (R2 = 0.90), as well as in patients with lymphoproliferative diseases (R2 = 0.90) and myeloproliferative diseases (R2 = 0.90). The correlation between Test 1 and the gold standard was observed in the overall sample (R2 = 0.68), as well as in patients with lymphoproliferative diseases (R2 = 0.79) and myeloproliferative diseases (R2 = 0.53). (4) Conclusions: The CUBE 30 TOUCH appears to be a more trustworthy tool for evaluating ESR in these pathologies.

Treatment pattern and changes in oral glucocorticoid dose after tocilizumab treatment in patients with adult Still's disease: An analysis of a Japanese claims database

AIM

Intravenous tocilizumab (TCZ-IV) was approved for the treatment of adult Still's disease (ASD) in Japan in May 2019 based on its efficacy and safety in a phase III randomized controlled trial. This study determined treatment patterns in patients with ASD and assessed oral glucocorticoid (GC) dose changes after TCZ-IV administration in Japanese clinical practice.

METHODS

Patients in the Medical Data Vision database aged 16 years or older with one or more of International Classification of Diseases, 10th revision codes M061 (ASD) or M082 (systemic juvenile idiopathic arthritis) during January 2017-March 2021 (cohort 1) and those initiating TCZ-IV during May 2019-March 2021 (cohort 2) were included.

RESULTS

In cohort 1, the proportion of patients who were prescribed interleukin-6 inhibitors (mainly TCZ-IV) increased from 10.8% (January-April 2019 [before TCZ-IV approval]; n = 2002) to 18.3% (January-March 2021 [after TCZ-IV approval]; n = 2008). In cohort 2 (n = 193), 84.5% of patients were on oral GCs (≤5 mg/day: 23.8%) at index date (initial TCZ-IV prescription date); 46/70 (65.7%) were on oral GC at 5 mg/day or higher 12 months after TCZ-IV treatment (primary outcome). After 12 months of treatment, the TCZ-IV retention rate was 73.6% and the TCZ-IV administration interval was every 4 weeks and every 2 weeks in 31.9% and 27.7% of patients, respectively.

CONCLUSION

The use of interleukin-6 inhibitors increased by 7.5% points in Japanese patients with ASD ~2 years after TCZ-IV approval, suggesting that an unmet medical need existed. This study suggests the potential GC-sparing effect of TCZ-IV in patients with ASD in clinical practice.

The Evolving Etiologic and Epidemiologic Portrait of Pericardial Disease

Pericardial disease includes a variety of conditions, including inflammatory pericarditis, pericardial effusions, constrictive pericarditis, pericardial cysts, and primary and secondary pericardial neoplasms. The true incidence of this varied condition is not well established, and the causes vary greatly across the world. This review aims to describe the changing pattern of epidemiology of pericardial disease and to provide an overview of causative etiologies. Idiopathic pericarditis (assumed most often to be viral) remains the most common etiology for pericardial disease globally, with tuberculous pericarditis being most common in developing countries. Other important etiologies include fungal, autoimmune, autoinflammatory, neoplastic (both benign and malignant), immunotherapy-related, radiation therapy-induced, metabolic, postcardiac injury, postoperative, and postprocedural causes. Improved understanding of the immune pathophysiological pathways has led to identification and reclassification of some idiopathic pericarditis cases into autoinflammatory etiologies, including immunoglobulin G (IgG)4-related pericarditis, tumour necrosis factor receptor-associated periodic syndrome (TRAPS), and familial Mediterranean fever in the current era. Contemporary advances in percutaneous cardiac interventions and the recent COVID-19 pandemic have also resulted in changes in the epidemiology of pericardial diseases. Further research is needed to improve our understanding of the etiologies of pericarditis, using the assistance of contemporary advanced imaging techniques and laboratory testing. Careful consideration of the range of potential causes and local epidemiologic patterns of causality are important for the optimization of diagnostic and therapeutic approaches.

A Challenging Case of Adult-Onset Still's Disease Complicated by Macrophage Activation Syndrome With Multiorgan Failure

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disease that involves the excessive production of proinflammatory cytokines. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immune-mediated disorder that can be primary or secondary to malignancy, infections, and autoimmune diseases. We present an interesting case of a young female with adult-onset Still's disease that commenced during pregnancy. Whole-body fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) scan showed diffuse uptake in the spleen and bone marrow with widespread lymphadenopathy. During the delayed diagnostic process to exclude lymphoproliferative malignancy, she developed severe HLH/macrophage activation syndrome (MAS) with multiorgan failure. In this case report, we described the challenges faced during the diagnosis of AOSD. We also highlighted the importance of using clinical criteria to aid in the early diagnosis and management of AOSD patients and the role of FDG-PET/CT scans in patients with AOSD. Additionally, we discussed the management aspects for patients with macrophage activation syndrome.

Persistent Pancytopenia as a Long-COVID Manifestation in a Patient with Adult-Onset Still's Disease: A Case Report

Background: Adult-onset Still's disease (AOSD) is a rare rheumatic inflammatory condition with an extremely heterogeneous clinical presentation and systemic impairment. Uncommon manifestations may be challenging to manage, especially in patients with previous severe acute SARS-CoV-2 infection. For the first time, we report the case of a patient affected by refractory AOSD presenting with severe pancytopenia as a long-COVID manifestation. The purpose of this case report is to illustrate the clinical presentation, diagnostic and therapeutic management of this unusual manifestation. Moreover, we examine the mechanisms that are potentially responsible for the onset of the pancytopenia observed in our patient. Case presentation: We describe the case of a 40-year-old male who presented with a history of fever for 2 years, arthralgia, maculopapular salmon-pink rash and a previous SARS-CoV-2 infection which required admission to intensive care. The patient's laboratory results revealed elevated inflammatory markers levels (erythrocyte sedimentation rate and C-reactive protein), hyperferritinemia and severe pancytopenia that needed multiple transfusions. A diagnosis of AOSD was made based on clinical and laboratory presentation after excluding neoplastic, infectious and other rheumatic diseases. The previous empirical treatment was not adequate to control the condition; therefore, treatment with high-dose steroids, canakinumab and epoetin alfa was started and led to the resolution of the man's symptoms and a reduction in inflammatory marker levels, whereas blood cell count remained stable without a need for further blood transfusions. The patient is currently under rheumatologic and hematologic follow-up every month. Conclusions: Neither AOSD nor SARS-CoV-2 infection usually manifests with pancytopenia, except in hemophagocytic syndrome or immunodeficient patients, respectively. Identifying the underlying etiology of pancytopenia is mandatory to establish a prompt treatment that generally resolves the disorder. However, in our case, all common causes of pancytopenia were excluded, suggesting a potential manifestation of the long-COVID syndrome. Despite the resolution of the acute infection and the remarkable treatment of AOSD, pancytopenia persists. Herein, we propose for refractory AOSD patients with previous SARS-CoV-2 infection a novel approach to the diagnosis and treatment of pancytopenia.

A Streamlined Diagnostic Process Improved the Outcomes of Patients with Adult-Onset Still's Disease: A Single-Center Retrospective Observational Study

INTRODUCTION

The diagnosis of adult-onset Still's disease (AOSD) is often delayed due to its clinical heterogeneity and lack of pathognomic features. Hence, there is an unmet need for an efficient diagnostic process. The major aim of this study was to compare the differences in disease outcomes between two groups of AOSD patients with and without implementation of the streamlined diagnostic process (SDP).

METHODS

Of 172 febrile patients with skin rash and/or arthralgia, 112 individuals had AOSD. The tentative diagnosis of AOSD or non-AOSD was made with or without the SDP implementation. The selection criteria for AOSD outcomes analysis were as follows: (1) age at study entry older than 20 years, (2) fulfillment of the Yamaguchi criteria for AOSD diagnosis, and (3) a follow-up period longer than 6 months after initiation of therapy. Three outcome parameters were evaluated, including diagnosis lag period, the proportion of "early diagnosis," and the proportion of achieving disease remission after a 6-month therapy.

RESULTS

The SDP was implemented for expediting AOSD diagnosis in 41 (36%) enrolled patients (SDP-implemented group). The diagnosis lag period was significantly shorter in the SDP-implemented group (median 2.0 weeks, interquartile range [IQR] 1.0-2.5 weeks) than in the non-SDP-implemented group (4.0 weeks, IQR 2.0-6.0 weeks, p < 0.001). A significantly higher proportion of "early diagnosis" was also found in the SDP-implemented group (75.6%) compared with the non-SDP-implemented group (33.8%, p < 0.001). We revealed a significantly higher proportion of achieving remission in the SDP-implemented group (85.4%) compared with the non-SDP-implemented group (67.6%, p < 0.05). Logistic regression analysis revealed SDP implementation as a potential predictor of achieving disease remission.

CONCLUSIONS

Implementing an SDP for expediting diagnosis could improve outcomes for AOSD patients. This diagnostic process increased the early diagnosis rate and led to a higher disease remission rate. However, the beneficial effects of SDP implementation need further external validation.

Increased incidence of adult-onset Still's disease in association with COVID-19 vaccination and SARS-CoV-2 infection

BACKGROUND

Adult-onset Still's disease (AOSD) is a multi-system, auto-inflammatory disease characterized by fever, arthralgia, typical rash, leukocytosis, sore throat, and liver dysfunction, among other symptoms. Retrospective studies about the frequencies of AOSD have shown that this disease is very rare. However, there has been an increased scientific interest in the last 2 years, as numerous case studies on AOSD have been published. These case studies describe the occurrence of AOSD after SARS-CoV-2 infection and/or COVID-19 vaccination.

METHODS

We analyzed the incidence of AOSD to examine a potential association between AOSD and SARS-CoV-2 infection and/or COVID-19 vaccination. The TriNetX dataset consists of 90 million patients. We found 8474 AOSD cases, which we analyzed regarding SARS-CoV-2 infection and/or vaccination status. We also analyzed the cohorts considering demographic data, lab values, co-diagnoses and treatment pathways.

RESULTS

We divided the AOSD cases into four cohorts: primary cohort (AOSD), Cov cohort (AOSD + SARS-CoV-2 infection), Vac cohort (AOSD + COVID-19 vaccination) and Vac + Cov cohort (AOSD + COVID-19 vaccination + SARS-CoV-2 infection). For the primary cohort, we found an annual incidence of 0.35 per 100.000. We found an association between AOSD and SARS-CoV-2 infection and/or COVID-19 vaccination. According to the numerical analysis, the incidence of AOSD doubled for the Cov cohort and Vac cohort. Moreover, the incidence of AOSD was 4.82 times higher for Vac + Cov cohort. The lab values for inflammatory markers were increased. Co-diagnoses such as rash, sore throat, and fever appeared in all AOSD cohorts, with the highest occurrences in the AOSD + COVID-19 vaccination + SARS-CoV-2 infection cohort. We identified several lines of treatments, mainly in association with adrenal corticosteroids.

CONCLUSIONS

This research supports the assumption of an association between AOSD and SARS-CoV-2 infection and/or COVID-19 vaccination. However, AOSD remains a rare disease and the usage of vaccines to fight the COVID-19 pandemic should not be questioned because of the increased incidence of AOSD.

A review of the pleiotropic actions of the IFN-inducible CXC chemokine receptor 3 ligands in the synovial microenvironment

Chemokines are pivotal players in instigation and perpetuation of synovitis through leukocytes egress from the blood circulation into the inflamed articulation. Multitudinous literature addressing the involvement of the dual-function interferon (IFN)-inducible chemokines CXCL9, CXCL10 and CXCL11 in diseases characterized by chronic inflammatory arthritis emphasizes the need for detangling their etiopathological relevance. Through interaction with their mutual receptor CXC chemokine receptor 3 (CXCR3), the chemokines CXCL9, CXCL10 and CXCL11 exert their hallmark function of coordinating directional trafficking of CD4+ TH1 cells, CD8+ T cells, NK cells and NKT cells towards inflammatory niches. Among other (patho)physiological processes including infection, cancer, and angiostasis, IFN-inducible CXCR3 ligands have been implicated in autoinflammatory and autoimmune diseases. This review presents a comprehensive overview of the abundant presence of IFN-induced CXCR3 ligands in bodily fluids of patients with inflammatory arthritis, the outcomes of their selective depletion in rodent models, and the attempts at developing candidate drugs targeting the CXCR3 chemokine system. We further propose that the involvement of the CXCR3 binding chemokines in synovitis and joint remodeling encompasses more than solely the directional ingress of CXCR3-expressing leukocytes. The pleotropic actions of the IFN-inducible CXCR3 ligands in the synovial niche reiteratively illustrate the extensive complexity of the CXCR3 chemokine network, which is based on the intercommunion of IFN-inducible CXCR3 ligands with distinct CXCR3 isoforms, enzymes, cytokines, and infiltrated and resident cells present in the inflamed joints.

Systematic review on the use of biologics in adult-onset still's disease

This systematic review (SR) describes the efficacy and safety of biologic disease modifying anti-rheumatic drugs (bDMARDs) for patients with adult-onset Still's disease (AOSD). Three randomised controlled trials (RCTs), one retrospective case series of multiple interventions, and 17 case series of single interventions met the inclusion criteria for this SR. Comparisons of biologic therapy in AOSD were only available against conventional DMARDs in one RCT and against placebo in two RCTs. There was a lack of common assessment criteria, meaning treatment efficacy across studies could not be compared. Uncontrolled retrospective case series suggested that bDMARDs have an effect for patients with AOSD, but these studies did not provide comparative data to show whether bDMARDs were more effective than other interventions or, whether any bDMARD was more effective than another bDMARD. However, there was evidence that bDMARDs could reduce steroid dose. Safety data from all included studies showed that bDMARDs appear to be a safe alternative to conventional DMARDs. This SR has highlighted the need for larger comparative studies in AOSD and has shown the need to standardize the definition of therapeutic response in AOSD. This would allow comparisons between studies in order to gain clarity on which bDMARDs may be more effective treatments for AOSD.

High-titer anti-interferon-γ neutralizing autoantibodies linked to opportunistic infections in patients with adult-onset still's disease

Objective

Neutralizing anti-interferon (IFN)-γ autoantibodies are linked to opportunistic infections (OIs). To explore the association between anti-IFN-γ autoantibodies and OIs in patients with adult-onset Still's disease (AOSD), we aimed to examine the ability of these autoantibodies to blockade signal transducer and activator of transcription (STAT1)-phosphorylation and chemokines production.

Methods

Serum titers of anti-IFN-γ autoantibodies were quantified using ELISA in 29 AOSD and 22 healthy controls (HC). The detectable autoantibodies were verified with immunoblotting assay, and their neutralizing capacity against IFN-γ-signaling was evaluated with flow-cytometry analysis and immunoblotting. IFN-γ-mediated production of supernatant chemokines, including monocyte chemoattractant protein-1 (MCP-1) and IFN-γ inducible protein-10 (IP-10), were measured by ELISA.

Results

Among 29 AOSD patients, high titers of anti-IFN-γ neutralizing autoantibodies were detectable in two patients with OIs. Immunoblotting assay revealed more effective inhibition of STAT1-phosphorylation in THP-1 cells treated with sera from autoantibody-positive AOSD patients (56.7 ± 34.79%) compared with those from HC (104.3 ±29.51%), which was also demonstrated in flow-cytometry analysis (47.13 ± 40.99 vs. 97.92 ± 9.48%, p < 0.05). Depleted serum IgG from anti-IFN-γ autoAbs-positive AOSD patients with OIs restored phosphorylated STAT-1 upon IFN-γ treatment. Sera from autoantibody-positive AOSD patients more effectively inhibited IFN-γ-mediated production of MCP-1 (45.65 pg/ml) and IP-10 (22.44 pg/ml) than sera from HC (263.1 pg/ml and 104.0 pg/ml, both p < 0.05). Serum samples showing the strongest inhibition of IFN-γ-signaling were from two patients with high-titer autoantibodies and OIs.

Conclusion

AOSD patients have a high positive rate and titers of anti-IFN-γ autoantibodies. The remarkable blockade effect of high-titer autoantibodies on IFN-γ-mediated STAT1-phosphorylation and chemokines could make these patients susceptible to OIs.

Adult-onset still's disease and budd-chiari syndrome: A case report

Adult onset still's disease (AOSD) is a rare autoinflammatory disease displaying with a wide range of non-specific symptoms and budd-chiari syndrome (BCS) is an uncommon disorder characterized by obstruction of hepatic venous outflow. We present the case of a young patient who presented with persistent fever, sore throat, elbow, hand fingers and knees arthralgia with abdominal pain. The patient's symptoms had started 7 days before the referral. Imaging and laboratory data led to the diagnosis of BCS in the context of AOSD. The patient treated with corticosteroid in combination of warfarin with favorable outcome and complete improvement of signs and symptoms. We came to this conclusion AOSD complicated with BCS is a rare but potentially life-threatening entity. Clinicians should be aware of this complication.

Adult-onset Still's disease in Western Australia: Epidemiology, comorbidity and long-term outcome

AIM

Adult-onset Still's disease (ASD) is a rare, potentially life-threatening autoinflammatory condition. As reported prevalence shows regional variation and long-term outcome data are scarce, we investigated epidemiology and long-term health outcomes of ASD in Western Australia (WA).

METHODS

Population-based cohort study using longitudinally linked administrative health data from all WA hospitals between 1999 and 2013 for ASD patients (ICD-10-AM M06.1) and controls matched for age, gender, and index year. Rate ratios and odds ratios (RR/OR) with 95% confidence intervals (CI) compared ASD patients with controls.

RESULTS

The average ASD incidence (n = 52) was 0.22/100 000 with 2.4/100 000 point-prevalence as of December 31, 2013. ASD patients (median age 41.5 years, 59.6% female) had higher odds of previous liver disease (OR 2.67, 95% CI 1.31-5.45), fever (OR 54.10, 95% CI 6.60-433.0), rash (OR 15.70, 95% CI 4.08-60.80), and serious infections (OR 4.36, 95% CI 2.11-22.80) than controls. Despite biological disease-modifying antirheumatic drugs in 27% of patients, ASD patients had higher odds for joint replacement (n = 7, 13.5%) (OR 45.5, 95% CI 4.57-93.70), osteoporosis (OR 31.3, 95% CI 3.43-97), and serious infections (RR 5.68; 95% CI 6.61-8.74) during follow up. However, crude mortality (11.5% vs 7.5%; P = 0.34), survival at 1 and 5 years (P= 0.78), and last modified Charlson Comorbidity score (median 2 vs 2) were similar between groups.

CONCLUSION

The epidemiology and demographics of ASD in Western Australia fall within the internationally reported range. ASD patients present increased rates of liver disease, rash, and serious infections before disease onset. Mortality following ASD was not increased for 5 years despite high rates of chronic arthritis requiring joint replacement, serious infections, and osteoporosis.

Adult-Onset Still's Disease-A Complex Disease, a Challenging Treatment

Adult-onset Still's disease (AOSD) is a systemic inflammatory disorder with an unknown cause characterized by high-spiking fever, lymphadenopathy, hepatosplenomegaly, hyperferritinemia, and leukocytosis. The clinical course can be divided into three significant patterns, each with a different prognosis: Self-limited or monophasic, intermittent or polycyclic systemic, and chronic articular. Two criteria sets have been validated. The Yamaguchi criteria are the most generally used, although the Fautrel criteria offer the benefit of adding ferritin and glycosylated ferritin values. AOSD's pathogenesis is not yet completely understood. Chemokines and pro-inflammatory cytokines, including interferon (IFN)-γ, tumor necrosis factor α (TNFα), interleukin (IL)-1, IL-6, IL-8, and IL-18, play a crucial role in the progression of illness, resulting in the development of innovative targeted therapeutics. There are no treatment guidelines for AOSD due to its rarity, absence of controlled research, and lack of a standard definition for remission and therapy objectives. Non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids (CS), and conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) are used in AOSD treatment. Biological therapy, including IL-1, IL-6, IL-18, and IL-17 inhibitors, as well as TNFα or Janus-kinases (JAKs) inhibitors, is administered to patients who do not react to CS and csDMARDs or achieve an inadequate response.

Perspectives on the use of non-biological pharmacotherapy for adult-onset Still's disease

INTRODUCTION

The treatment of the patients with adult-onset Still's disease (AOSD) remains largely empirical and it is based on the administration of immunosuppressive drugs. In this work, we described the use of non-biological pharmacotherapies for AOSD.

AREA COVERED

Although nonsteroidal anti-inflammatory drugs (NSAIDs) are employed during the diagnostic phase, glucocorticoids (GCs) are the first-line therapy, administered at the beginning of the disease. As second-line therapy, conventional synthetic disease modifying anti-rheumatic drugs (csDMARDs) are used when GCs do not fully control the disease and/or to reduce the dosage of concomitant GCs. Methotrexate (MTX) is the most commonly administered csDMARDs whereas calcineurin inhibitors (CNIs) are used in severe patients. The lack of achievement of clinical response may lead to the administration of biologic DMARDs, with or without csDMARDs.

EXPERT OPINION

The management of AOSD may benefit from the administration of non-biological pharmacotherapies, including GCs, MTX, and CNIs. These therapies showed efficacy in inducing a clinical response, in managing life-threatening complications, and may be well tolerated in combination with biologic DMARDs. However, further specific studies are needed to fully clarify the specific role of such drugs in clinical practice to improve the management of AOSD and to provide a more tailored treatment.

Adult-onset Still's disease with concurrent acute necrotizing encephalopathy: a case report

Background

Acute necrotizing encephalopathy (ANE) is a rare encephalopathy characterized by multiple symmetrical brain lesions, mainly involving thalami. Adult-onset Still’s disease (AOSD) is a rare systemic inflammatory condition of unknown cause characterized by fever, sore throat, rash and joint pain. Both entities are considered to be triggered by infections and associated with hypercytokinemia.

Case presentation

A 46-year-old male was diagnosed with AOSD at local hospital because of 3-week-long high fever, sore throat, arthralgia, transient skin rash, lymphadenopathy, leukocytosis, hyperferritinemia, and absence of antinuclear antibodies (ANA) and rheumatoid factor (RF). Corticosteroids were not used because of delayed diagnosis. Three weeks after the onset, the patient suddenly fell unconscious and was transferred to our hospital. Brain CT and MRI revealed symmetrical lesions involving thalami, striatum and brain stem, consistent with ANE. One day after admission, his condition aggravated and brain CT revealed hemorrhage in the lesions. He died 3 days after admission.

Conclusion

We report a rare case of ANE preceded by AOSD. The underlying mechanism is still unclear. Early recognizing of the two conditions is difficult but prognostically important.

Diagnostic utility of clinical characteristics, laboratory tests, and serum ferritin in diagnosis of adult-onset Still disease

The diagnosis of adult-onset Still disease (AOSD) is challenging with ambiguous clinical presentation and no specific serological markers. We aim to evaluate the diagnostic utility of clinical, laboratory and serum ferritin features in established AOSD patients. We included all patients >18 years who were admitted to 2 tertiary medical centers (2003-2019) with serum ferritin above 1000 ng/mL. AOSD patients and non-AOSD controls were matched in 1:4 ratio for age and sex. The primary outcomes were sensitivity, specificity, positive/negative likelihood ratio and area under the curve (AUC) using clinical and laboratory characteristics based on the Yamaguchi classification criteria, in addition to serum ferritin. We identified 2658 patients with serum ferritin above 1000 ng/m, of whom 36 diagnosed with AOSD and 144 non-AOSD matched controls. Presence of arthralgia/arthritis showed the highest sensitivity (0.74), specificity (0.93), positive likelihood ratio (10.69), negative likelihood ratio (0.27) and AUC (0.83, 95% confidence interval 0.74-0.92) to the diagnosis of AOSD. On the other hand, serum ferritin showed variation and poorer results, depends on the chosen ferritin cutoff. Joint involvement showed the best diagnostic utility to establish the diagnosis of AOSD. Although clinicians use often elevated ferritin levels as an anchor to AOSD, the final diagnosis should be based on thorough clinical evaluation.

Methotrexate Failure in the Treatment of Adult-Onset Still’s Disease: A Case Report

Adult-onset Still's disease (AOSD) is a rheumatological condition associated with significant morbidity and mortality. Typically a diagnosis of exclusion, the therapeutic management has relied mainly on symptom control and immune suppression. Methotrexate (MTX), a disease-modifying anti-rheumatoid drug (DMARDs), has become a drug of choice in treating several autoimmune conditions, including AOSD. Unfortunately, despite being largely effective, this medication can result in treatment failure, exacerbation, and a flare of symptoms. We present the case of a 31-year-old male who presented to us with weakness and palpitations, who was ultimately found to have a flare of his Still's disease, despite being on MTX therapy. Our hope is to encourage a suspicion for treatment failure in patients with similar symptoms, in order to encourage a faster initiation of alternative therapies to alleviate their discomfort.

Bibliometrics analysis on the research status and trends of adult-onset Still’s disease: 1921-2021

Objectives

The aim of this research is to discuss the research status, hotspots, frontiers and development trends in the field of adult-onset Still’s disease (AOSD) based on bibliometrics and visual analysis by CiteSpace software.

Methods

The relevant research articles on AOSD from 1921 to 2021 were retrieved from the Scopus database. CiteSpace software was used to form a visual knowledge map and conduct analysis for the countries/regions, journals, authors, keywords, clusters, research hotspots and frontiers of the included articles.

Results

There were 2,373 articles included, and the number of articles published during 1921-2021 is increasing. The country with the highest number of articles published was Japan (355, 14.96%), followed by the United States (329, 13.86%) and France (215, 9.06%). The author with the highest number of publications is Ansell, Barbara M. (30, 1.26%), and the author with the highest co-citation frequency is Yamaguchi, Masaya (703). Clinical Rheumatology is the journal with the highest publication frequency. The top five cluster groups were “joint”, “differential diagnosis”, “prednisolone”, “methotrexate” and “macrophage activation syndrome”. The diagnosis, treatment and pathogenesis of AOSD form the main research fields, and prognosis and complications are the research hotspots and trends.

Conclusions

The global research field in AOSD has expanded in the past 100 years. The complications and new pathogenesis of AOSD are hotspots in this field and need further study in the future.

Interleukin-18: a biomarker with therapeutic potential in adult-onset Still's disease

INTRODUCTION

Adult-onset Still's disease (AOSD) is an autoinflammatory disease driven by the innate immune response. Given the ambiguity in clinical presentation and lack of specific diagnostic biomarkers, AOSD diagnosis is usually delayed in the early stage. Because AOSD is a rare disease with clinical heterogeneity, there is no consensus on its treatment currently. This review summarizes the current research evidence regarding the pathogenic role and the diagnostic or therapeutic potential of interleukin (IL)-18 in AOSD.

AREAS COVERED

We searched the MEDLINE database using the PubMed interface and reviewed English-language literature from 1971 to 2022. This review focusing on IL-18 discusses its pathogenic role and clinical implications in AOSD.

EXPERT OPINION

NLRP3-inflammasome activation with IL-18 overproduction plays a pathogenic role in AOSD. IL-18 is closely linked to the clinical manifestations and disease activity of AOSD and may be a diagnostic biomarker. Given its pathogenic role in AOSD, IL-18 could become a potential therapeutic target. IL-18 binding protein (IL-18BP) negatively regulates the biological activity of IL-18 by inhibiting IL-18 signaling, and a clinical trial revealed that IL-18BP (Tadekinig alfa) treatment was well-tolerated and effective for AOSD. Recently, monoclonal antibodies against IL-18 have been under evaluation in a phase 1b trial.

Serosal Involvement in Adult-Onset Still's Disease: A Multicenter and Retrospective Study

BACKGROUND

This study evaluated the characteristics of serosal involvement in Adult-onset Still's disease.

METHODS

Patients meeting the Yamaguchi classification criteria were classified into AOSD with and without serosal involvement according to their manifestations and sonography/radiography. Clinical data were retrospectively reviewed from 102 AOSD patients of two centers.

RESULTS

Forty-two patients (41.2%) had serosal involvement. The frequencies of pulmonary infiltrate and impaired liver function were significantly higher in patients with serosal involvement (P=0.002 and P=0.007, respectively), who also had a higher modified systemic score (P=0.009). In addition, the percentages of CD3+ T cells (P<0.0001) and, especially, the CD8+ T cells (P=0.004) were significantly increased in the peripheral blood of AOSD patients with serosal involvement. Notably, patients with serosal involvement were more likely to develop MAS (P=0.047) and develop into chronic pattern (P=0.016) during the follow-up.

CONCLUSION

Patients with serosal involvement demonstrated the more severe disease activity and different immune phenotypes, and these patients were more likely to develop MAS, and they may require more aggressive treatment at an early time to control their systemic inflammation.

Clinical characteristics and treatment of elderly onset adult-onset Still's disease

Adult-onset Still’s disease (AOSD)—a systemic inflammatory disease—often occurs at a young age. Recently, elderly onset patient proportion has been increasing; however, data are limited. To evaluate the characteristics of elderly patients with AOSD in a multicenter cohort, we retrospectively analyzed 62 patients with AOSD at five hospitals during April 2008–December 2020. Patients were divided into two groups according to age at disease onset: younger-onset (≤ 64 years) and elderly onset (≥ 65 years). Clinical symptoms, complications, laboratory findings, treatment, and outcomes were compared. Twenty-six (41.9%) patients developed AOSD at age ≥ 65 years. The elderly onset group had a lower frequency of sore throat (53.8% vs. 86.1%), higher frequency of pleuritis (46.2% vs. 16.7%), and higher complication rates of disseminated intravascular coagulation (30.8% vs. 8.3%) and macrophage activation syndrome (19.2% vs. 2.8%) than the younger onset group. Cytomegalovirus infections were frequent in elderly onset patients (38.5% vs. 13.9%) but decreased with early glucocorticoid dose reduction and increased immunosuppressant and tocilizumab use. Elderly AOSD is not uncommon; these patients have different characteristics than younger-onset patients. Devising a way to control disease activity quickly while managing infections may be an important goal in elderly AOSD.

Application of Machine Learning for the Prediction of Etiological Types of Classic Fever of Unknown Origin

Background: The etiology of fever of unknown origin (FUO) is complex and remains a major challenge for clinicians. This study aims to investigate the distribution of the etiology of classic FUO and the differences in clinical indicators in patients with different etiologies of classic FUO and to establish a machine learning (ML) model based on clinical data. Methods: The clinical data and final diagnosis results of 527 patients with classic FUO admitted to 7 medical institutions in Chongqing from January 2012 to August 2021 and who met the classic FUO diagnostic criteria were collected. Three hundred seventy-three patients with final diagnosis were divided into 4 groups according to 4 different etiological types of classical FUO, and statistical analysis was carried out to screen out the indicators with statistical differences under different etiological types. On the basis of these indicators, five kinds of ML models, i.e., random forest (RF), support vector machine (SVM), Light Gradient Boosting Machine (LightGBM), artificial neural network (ANN), and naive Bayes (NB) models, were used to evaluate all datasets using 5-fold cross-validation, and the performance of the models were evaluated using micro-F1 scores. Results: The 373 patients were divided into the infectious disease group (n = 277), non-infectious inflammatory disease group (n = 51), neoplastic disease group (n = 31), and other diseases group (n = 14) according to 4 different etiological types. Another 154 patients were classified as undetermined group because the cause of fever was still unclear at discharge. There were significant differences in gender, age, and 18 other indicators among the four groups of patients with classic FUO with different etiological types (P < 0.05). The micro-F1 score for LightGBM was 75.8%, which was higher than that for the other four ML models, and the LightGBM prediction model had the best performance. Conclusions: Infectious diseases are still the main etiological type of classic FUO. Based on 18 statistically significant clinical indicators such as gender and age, we constructed and evaluated five ML models. LightGBM model has a good effect on predicting the etiological type of classic FUO, which will play a good auxiliary decision-making function.

Adult-Onset Still's Disease: A Case Report

Adult-onset Still's disease (AOSD) is a disorder that is occasionally seen. Autoinflammation is a generally accepted pathogenic mechanism leading to systemic signs and symptoms. We report the case of a young female presenting with high-grade fever, rash, and arthralgias. After a thorough assessment, the diagnosis of adult-onset Still's disease was made based on presenting symptoms and elevated serum ferritin, c-reactive protein (CRP), and absence of serologic markers and confirmed based on Yamaguchi criteria. She was treated with corticosteroids and achieved complete clinical remission.

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.

The clinical heterogeneity of adult onset Still's disease may underlie different pathogenic mechanisms. Implications for a personalised therapeutic management of these patients

Adult-onset Still's disease (AOSD) is a rare inflammatory disease of unknown aetiology usually affecting young adults and manifesting with a clinical triad of spiking fever, arthritis, and evanescent cutaneous rash. AOSD may be considered a highly heterogeneous disease, despite a similar clinical presentation, the disease course may be completely different. Some patients may have a single episode of the disease whereas others may evolve toward a chronic course and experience life-threatening complications. On these bases, to dissect the clinical heterogeneity of this disease, four different subsets were identified combining the manifestations at the beginning with possible diverse outcomes over time. Each one of these derived subsets would be characterised by a prominent different clinical feature from others, thus proposing dissimilar underlying pathogenic mechanisms, at least partially. Consequently, a distinct management of AOSD may be suggested to appropriately tailor the therapeutic strategy to these patients, according to principles of the precision medicine. These findings would also provide the rationale to recognise a different genetic and molecular profile of patients with AOSD. Taking together these findings, the basis for a precision medicine approach may be suggested in AOSD, which would drive a tailored therapeutic approach in these patients. A better patient stratification may also help in arranging specific designed studies to improve the management of patients with AOSD. Behind these different clinical phenotypes, distinct endotypes of AOSD may be suggested, probably differing in pathogenesis, outcomes, and response to therapies.

Adult-onset Still's disease after environmental exposure while working in Africa

Adult-onset Still's disease (AOSD) is characterised by a constellation of systemic inflammatory symptoms and typical laboratory findings like hyperferritinaemia. A high index of suspicion is needed to identify patients as diagnosis is primarily clinical and significant morbidity can result from delayed diagnosis. While AOSD may be self-limited, some patients experience flares over years and require more aggressive treatment approaches. Aetiology is unknown but can be triggered by viral infections and other environmental factors in a susceptible genetic host. We present a case of AOSD triggered after exposure to a sap-like liquid while working in Africa. This inciting event occurred as part of a hostile act towards the patient and involved medicinal practices traditional to the area. Our case highlights the more chronic course of AOSD, which requires escalating biological treatment to avoid long-term corticosteroids, as well as the juncture between traditional and modern medical practices.

Adult-onset Still's disease with multiple lymphadenopathy: a case report and literature review

BACKGROUND

Adult-onset Still's disease (AOSD) often presents with systemic multiple lymphadenopathy. In addition to the common paracortical and mixed patterns in AOSD lymph node histopathological features, other morphological patterns include diffuse, necrotic, and follicular patterns. However, to date, there have been few reports on the histopathological description of AOSD lymph nodes.

CASE PRESENTATION

An 18-year-old woman presented 2 months earlier with pain in her large joints with painless rash formation; bilateral posterior cervical lymph node, left supraclavicular lymph node, and left posterior axillary lymph node enlargement, and no tenderness. Left cervical lymph node resection was performed for pathological examination. The lymph node structure was basically preserved, and subcapsular and medullary sinus structures were observed. Many histiocytes in the sinus were observed, the cortical area was reduced, a few lymphoid follicles of different sizes were observed, and some atrophy and hyperplasia were noted. The lymphoid tissue in the paracortical region of the lymph node was diffusely proliferative and enlarged, mainly comprising histiocytes with abundant cytoplasm, immunoblasts and numerous lymphocytes with slightly irregular, small- to medium-sized nuclei. Nuclear karyorrhexis was easily observed, showing a few nuclear debris and the "starry sky" phenomenon, accompanied by abundantly branching high endothelial small vessels with few scattered plasma cells and eosinophil infiltration. Lymphoid follicle immunophenotype with reactive proliferative changes was observed. Approximately 40% of the cells in the paracortical region were positive for Ki-67, and the histiocytes expressed CD68, CD163, and some expressed S-100, with the absence of myeloperoxidase. The immunoblasts expressed CD30 and CD20, not ALK or CD15. Background small- to medium-sized T cells expressed CD2, CD3, CD5, CD7, CD4, and CD8; the number of CD8-positive T cells was slightly predominant, and a small number of T cells expressed granzyme B and T-cell intracellular antigen 1. The patient received a comprehensive medical treatment after the operation, and her condition was stable without progression at the 11-month follow-up evaluation.

CONCLUSIONS

The pathological features of AOSD lymphadenopathy raises the awareness of AOSD among pathologists and clinicians and aids in the diagnosis and differential diagnosis of AOSD lymphadenopathy from other reactive lymphadenopathies (lupus lymphadenitis, etc.) and lymphomas.

The effectiveness of tocilizumab in treating refractory adult-onset Still's disease with dichotomous phenotypes: IL-18 is a potential predictor of therapeutic response

OBJECTIVE

Adult-onset Still's disease (AOSD) is a systemic inflammatory disorder with clinical heterogeneity. Although tocilizumab (TCZ), an interleukin (IL)-6 receptor inhibitor, is an effective treatment for AOSD, the evidence regarding its efficacy on systemic or articular subtypes is conflicting. Furthermore, the predictors of therapeutic response are still elusive and worthy of exploration.

METHODS

This two-center retrospective study analyzed the effectiveness and safety profile of TCZ treatment in 28 patients with refractory AOSD. The 28-joint disease activity score (DAS28) and systemic activity score were assessed before and during TCZ treatment period at weeks 12, 24, 36, and 48. Plasma levels of proinflammatory cytokines at baseline were determined using ELISA method.

RESULTS

Among the systemic subtype patients, 10 (58.8%), 13 (76.5%), 14 (82.4%), and 15 (88.2%) patients achieved complete remission at week 12, 24, 36, and 48, respectively, in comparison to 2 (22.2%), 5 (55.6%), 6 (66.7%), and 7 (77.8%) who achieved disease remission (DAS28 < 2.6) at weeks 12, 24, 36, and 48, respectively, among articular subtype patients. The systemic activity scores and inflammatory parameters were significantly decreased after 12-week TCZ therapy, and TCZ could significantly reduce corticosteroid dose in AOSD patients. Multivariate analysis reveals that baseline IL-18 level is a significant predictor of poor therapeutic response at week 24 (odds ratio 7.86, p < 0.05).

CONCLUSION

AOSD patients refractory to high-dose corticosteroids and methotrexate may respond well to TCZ treatment with a steroid-sparing effect and an acceptable safety. A high baseline IL-18 level may be a predictor of poor therapeutic response. Key Points • Tocilizumab may be effective and well-tolerated in refractory AOSD patients regardless of disease subtypes. • High plasma levels of IL-18 may predict poor response to tocilizumab in AOSD patients.

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.

Interleukin-18 Is a Potential Biomarker to Discriminate Active Adult-Onset Still's Disease From COVID-19

Background

Hyperinflammation with dysregulated production of galectins and cytokines may develop in COVID-19 or adult-onset Still's disease (AOSD). Given the similar clinical features in both diseases, it is necessary to identify biomarkers that can differentiate COVID-19 from AOSD. However, the related data remain scarce currently.

Methods

In this cross-sectional study, plasma levels of galectin-3, galectin-9, and soluble TIM-3 (sTIM-3) were determined by ELISA in 55 COVID-19 patients (31 non-severe and 24 severe), 23 active AOSD patients, and 31 healthy controls (HC). The seropositivity for SARS-CoV-2 was examined using an immunochromatographic assay, and cytokine profiles were determined with the MULTIPLEX platform.

Results

Significantly higher levels of galectin-3, galectin-9, IL-1β, IL-1Ra, IL-10, IFN-α2, IL-6, IL-18, and TNF-α were observed in severe COVID-19 and active AOSD patients compared with HC (all p<0.001). AOSD, but not COVID-19, showed significantly higher IFN-γ and IL-17A compared with HC (both p<0.01). Moreover, active AOSD patients had 68-fold higher IL-18 levels and 5-fold higher ferritin levels than severe COVID-19 patients (both p<0.001). IL-18 levels at the cut-off value 190.5pg/mL had the highest discriminative power for active AOSD and severe COVID-19, with AUC 0.948, sensitivity 91.3%, specificity 95.8%, and accuracy of 91.5% (p<0.005). Multivariate regression analysis revealed IL-18 as a significant predictor of active AOSD (p<0.05).

Conclusion

Active AOSD patients share features of hyperinflammation and cytokine storm with severe COVID-19 patients but possess a distinct cytokine profile, including elevated IL-18, IL-6, IFN-γ, and IL-17A. IL-18 is a potential discriminator between AOSD and COVID-19 and may significantly predict active AOSD.

The combined prevalence of classified rare rheumatic diseases is almost double that of ankylosing spondylitis

BACKGROUND

Rare diseases (RDs) affect less than 5/10,000 people in Europe and fewer than 200,000 individuals in the United States. In rheumatology, RDs are heterogeneous and lack systemic classification. Clinical courses involve a variety of diverse symptoms, and patients may be misdiagnosed and not receive appropriate treatment. The objective of this study was to identify and classify some of the most important RDs in rheumatology. We also attempted to determine their combined prevalence to more precisely define this area of rheumatology and increase awareness of RDs in healthcare systems. We conducted a comprehensive literature search and analyzed each disease for the specified criteria, such as clinical symptoms, treatment regimens, prognoses, and point prevalences. If no epidemiological data were available, we estimated the prevalence as 1/1,000,000. The total point prevalence for all RDs in rheumatology was estimated as the sum of the individually determined prevalences.

RESULTS

A total of 76 syndromes and diseases were identified, including vasculitis/vasculopathy (n = 15), arthritis/arthropathy (n = 11), autoinflammatory syndromes (n = 11), myositis (n = 9), bone disorders (n = 11), connective tissue diseases (n = 8), overgrowth syndromes (n = 3), and others (n = 8). Out of the 76 diseases, 61 (80%) are classified as chronic, with a remitting-relapsing course in 27 cases (35%) upon adequate treatment. Another 34 (45%) diseases were predominantly progressive and difficult to control. Corticosteroids are a therapeutic option in 49 (64%) syndromes. Mortality is variable and could not be determined precisely. Epidemiological studies and prevalence data were available for 33 syndromes and diseases. For an additional eight diseases, only incidence data were accessible. The summed prevalence of all RDs was 28.8/10,000.

CONCLUSIONS

RDs in rheumatology are frequently chronic, progressive, and present variable symptoms. Treatment options are often restricted to corticosteroids, presumably because of the scarcity of randomized controlled trials. The estimated combined prevalence is significant and almost double that of ankylosing spondylitis (18/10,000). Thus, healthcare systems should assign RDs similar importance as any other common disease in rheumatology.

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.

An Update on the Pathogenic Role of Macrophages in Adult-Onset Still's Disease and Its Implication in Clinical Manifestations and Novel Therapeutics

Increasing evidence indicates a pivotal role of macrophages in innate immunity, which contributes to the pathogenesis of adult-onset Still's disease (AOSD). Despite the available reviews that summarized the pathogenic role of proinflammatory cytokines in AOSD, a systematic approach focusing on the crucial role of macrophages in this disease is still lacking. This review summarizes the updated functions of macrophages in AOSD and their implication in clinical manifestations and therapeutics. We searched the MEDLINE database using the PubMed interface and reviewed the English-language literature as of 31 March 2021, from 1971 to 2021. We focus on the existing evidence on the pathogenic role of macrophages in AOSD and its implication in clinical characteristics and novel therapeutics. AOSD is an autoinflammatory disease mainly driven by the innate immune response. Among the innate immune responses, macrophage activation is a hallmark of AOSD pathogenesis. The pattern recognition receptors (PRRs) on macrophages recognize pathogen-associated molecular patterns and damage-associated molecular patterns and subsequently cause overproduction of proinflammatory cytokines and recruit adaptive immunity. Some biomarkers, such as ferritin and gasdermin D, reflecting macrophage activation were elevated and correlated with AOSD activity. Given that macrophage activation with the overproduction of proinflammatory cytokines plays a pathogenic role in AOSD, these inflammatory mediators would be the therapeutic targets. Accordingly, the inhibitors to interleukin- (IL-) 1, IL-6, and IL-18 have been shown to be effective in AOSD treatment. Gaining insights into the pathogenic role of macrophages in AOSD can aid in identifying disease biomarkers and therapeutic agents for this disease.

The joint involvement in adult onset Still's disease is characterised by a peculiar magnetic resonance imaging and a specific transcriptomic profile

Adult onset Still's disease (AOSD) is a rare systemic autoinflammatory disease, characterised by fever, arthritis, and skin rash, and joint involvement is one of its clinical manifestations. The aims of this work were to assess joint involvement, to describe main patterns of involvement, and associated clinical characteristics. In this work, we aimed at assessing the joint involvement in AOSD by using MRI, to describe main patterns and associated clinical characteristics. In addition, we aimed at assessing the global transcriptomic profile of synovial tissues in AOSD to elucidate possible pathogenic pathways involved. We also evaluated the global transcriptomic profile of synovial tissues to elucidate possible pathogenic pathways involved in the disease. Thus, AOSD patients, who underwent to MRI exam on joints, were assessed to describe patterns of joint involvement and associated clinical characteristics. Some synovial tissues were collected for RNA-sequencing purposes. The most common MRI finding was the presence of synovitis on 60.5%, mainly in peripheral affected joints, with low to intermediate signal intensity on T1-weighted images and intermediate to high signal intensity on T2-fat-saturated weighted and STIR images. Bone oedema and MRI-bone erosions were reported on 34.9% and 25.6% MRI exams, respectively. Patients with MRI-bone erosions showed a higher prevalence of splenomegaly, a more frequent chronic disease course, lower levels of erythrocyte sedimentation rate, and ferritin. In AOSD synovial tissues, a hyper-expression of interleukin (IL)-1, IL-6, and TNF pathways was shown together with ferritin genes. In conclusion, in AOSD patients, the most common MRI-finding was the presence of synovitis, characterised by intermediate to high signal intensity on T2-fat-saturated weighted and STIR images. MRI-bone erosions and bone oedema were also observed. In AOSD synovial tissues, IL-1, IL-6, and TNF pathways together with ferritin genes resulted to be hyper-expressed.

Adult-onset Still's disease in focus: Clinical manifestations, diagnosis, treatment, and unmet needs in the era of targeted therapies

BACKGROUND

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disorder of unknown etiology, characterized by a clinical triad of high spiking fever, arthralgia (± arthritis), and evanescent skin rash. Management of AOSD poses several challenges, including difficulty in diagnosis and limited therapeutic options. In this review, we examined whether AOSD and systemic juvenile idiopathic arthritis (SJIA) represent a continuum of the same disease. We also explored the latest available evidence related to prevalence, clinical and laboratory manifestations, complications, diagnostic challenges, novel biomarkers, and treatment options in the era of biologics and identified the unmet needs of patients with AOSD.

METHODS

A comprehensive systematic literature search was performed in the Embase and MEDLINE (via PubMed) literature databases. The search was limited to human studies published in English from inception up to March 2020. Additionally, abstracts presented at various conferences were screened and hand searches were performed. Publications were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 123 publications were identified through the literature search, majority of which were case series and retrospective observational studies. AOSD and SJIA are widely considered part of the same disease spectrum owing to similarities in their clinical and biological features. The clinical presentation of AOSD is highly variable, accompanied by a broad spectrum of disease manifestations. Recent evidence suggests that the AOSD disease course can be classified into two distinct categories: "systemic" and "articular." Furthermore, AOSD patients may experience various life-threatening complications, such as macrophage activation syndrome - reported in as high as 23% of AOSD patients and considered to be the most severe complication characterized by a high mortality rate. The ambiguity in presentation and lack of serologic markers make the diagnosis of AOSD difficult, often leading to a delay in diagnosis. Given these limitations, the Yamaguchi and Fautrel criteria are the most widely used diagnostic tools in clinical practice. It has been observed that a clinical diagnosis of AOSD is generally reached by exclusion while investigating a patient with fever of unknown origin. Recent advances have demonstrated a major role of proinflammatory cytokines, such as interleukin (IL)-1, IL-6, IL-18, and IL-37, and other biomarkers in the pathogenesis and management of AOSD. Owing to the rarity of the disease, there are very limited clinical trials evaluating management strategies for AOSD. The current AOSD treatment paradigm includes non-steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids initially, conventional synthetic disease-modifying anti-rheumatic drugs in steroid-refractory patients, and biologics in those resistant to conventional treatment. Only a few country-specific guidelines for the management of AOSD have been published, and a treat-to-target approach, as previously recommended for SJIA, is still lacking. Canakinumab is the only FDA-approved biologic for the treatment of AOSD.

CONCLUSION

Emerging evidence supports that AOSD and SJIA represent a continuum of the same disease entity. Despite advancements in the understanding of AOSD, it continues to pose a substantial burden on patients and the healthcare systems, and substantial unmet needs exist across key domains such as the pathway to diagnosis, use of biomarkers in clinical practice, and standardized treatment strategies. Further research and collaboration is crucial for optimizing the diagnosis and management of AOSD patients.

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.

CARD8 SNP rs11672725 Identified as a Potential Genetic Variant for Adult-Onset Still's Disease

Adult-onset Still's disease (AOSD), an autoinflammatory disorder, is related to the dysregulation of NLR3-containing a pyrin domain (NLRP3)-inflammasome signaling. We aimed to investigate the associations of genetic polymorphisms of NLRP3-inflammasome signaling with AOSD susceptibility and outcome and to examine their functional property. Fifty-three candidate single-nucleotide polymorphisms (SNPs) involved in NLRP3-inflammasome response were genotyped using Sequenom MassArray on the samples from 66 AOSD patients and 128 healthy controls. The significant SNPs were validated by direct sequencing using a TaqMan SNP analyzer. Serum levels of associated gene products were examined by ELISA. One SNP rs11672725 of CARD8 gene was identified to be significantly associated with AOSD susceptibility by using MassArray and subsequent replication validation (p = 3.57 × 10^-7; odds ratio 3.02). Functional assays showed that serum CARD8 levels were significantly lower in AOSD patients (median, 10,524.6 pg/mL) compared to controls (13,964.1 pg/mL, p = 0.005), while levels of caspase-1, IL-1β and IL-18 were significantly higher in patients (107.1 pg/mL, 2.1 pg/mL, and 1495.8 pg/mL, respectively) than those in controls (99.0 pg/mL, 1.0 pg/mL, and 141.4 pg/mL, respectively). Patients carrying rs11672725CC genotype had significantly higher serum caspase-1 and IL-18 levels (121.3 pg/mL and 1748.6 pg/mL) compared to those with CT/TT genotypes (72.6 pg/mL, p = 0.019 and 609.3 pg/mL, p = 0.046). A higher proportion of patients with rs11672725CC genotype had a systemic pattern of disease outcome, which was linked to low CARD8 levels. A novel variant, rs11672725, of the CARD8 gene was identified as a potential genetic risk for AOSD. Patients carrying the rs11672725CC genotype and C allele had low CARD8 levels, and were predisposed to a systemic pattern with an elevated expression of inflammasome signaling.

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.

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 evolving with multiple organ failure and death: A case report and review of the literature

BACKGROUND

Adult-onset Still’s disease (AOSD) is a rare systemic inflammatory disease, which is characterized by daily fever and arthritis, with an evanescent rash and neutrophilic leukocytosis. To date, there has been no definite laboratory or imaging test available for diagnosing AOSD; the diagnosis is one of exclusion, which can be very challenging. In particular, AOSD patients may experience different complications affecting their clinical picture, management, and prognosis. The treatment of AOSD remains largely empirical and involves therapeutic agents.

CASE SUMMARY

We report the case of a 36-year-old woman who presented with fever, red rash, arthralgia, and sore throat. Her serum ferritin level and white blood cell count were markedly elevated, and the first diagnosis 22 years prior was "juvenile rheumatoid arthritis of systemic type". The patient was treated with prednisone, sulfasalazine, methotrexate, and leflunomide. After remission of her symptoms, the patient stopped taking the medications, and the disease recurred. Ultimately, the patient was diagnosed with adult-onset Still's disease. Relapse occurred several times due to self-medication withdrawal, and an interleukin-6 antagonist (tocilizumab/Actemra) was administered to control the disease. Recently, she was hospitalized because an incision did not heal, and the patient suddenly developed high fever and diarrhea during hospitalization. The patient's disease progressed violently and quickly developed into macrophage activation syndrome, disseminated intravascular coagulation, shock, and multiple organ failure. The patient had sudden cardiac arrest, and she died despite emergency rescue efforts.

CONCLUSION

AOSD patients need regular follow-up in the long-term treatment process, and must press formulary standard medication, and do not voluntarily withdraw or reduce the dose. Otherwise it may cause disease back-and-forth or serious life-threatening complications. Meanwhile, strict management of trauma, infections, tumors, and other diseases may contribute to improved outcomes in patients with complications.

Single-arm, open-label pilot intervention study to investigate an effect of oral 5-aminolevulinic acid plus sodium ferrous citrate on glucocorticoid reduction in patients with adult-onset Still disease: Study protocol for clinical trial (SPIRIT compliant)

BACKGROUND

Glucocorticoids are an important class of medication for patients with adult-onset Still disease (AOSD), however, relapse following glucocorticoid reduction and adverse events due to long-term effects of glucocorticoid are still problematic. It is of course essential to minimize the risk of treatment. Immunosuppressive therapies such as methotrexate and biologics including tocilizumab are used in glucocorticoid-dependent patients with AOSD, but no second-line treatments for patients with glucocorticoid dependence have been established yet. Given that these drugs also have the potential to cause adverse events, alternative treatments are sought. Recently, elevated heme oxygenase-1 (HO-1) has been reported in the serum of patients with AOSD, suggesting that HO-1 activity contributes to AOSD pathogenesis and may represent a new therapeutic target for the treatment of AOSD. The amino acid 5-aminolevulinic acid (5-ALA) is a non-proteinogenic δ amino acid in human body. An addition of ferrous iron to 5-ALA enhances heme biosynthesis. The increase in heme in vivo induces HO-1 production, a heme-degrading enzyme. Elevated HO-1 has been suggested to contribute to the pathogenesis of AOSD, and administration of 5-ALA and ferrous iron may be a potential treatment for AOSD.

METHODS/DESIGN

This study is a single-arm, open-label pilot intervention study using clinical endpoints to investigate the effects of oral 5-ALA with sodium ferrous citrate on glucocorticoid reduction in patients with AOSD receiving glucocorticoid therapy.

DISCUSSION

This pilot intervention study will provide evidence regarding the effectiveness and safety of 5-ALA/sodium ferrous citrate as a potential new therapeutic agent for glucocorticoid-dependent patients with AOSD.

TRIAL REGISTRATION

This study was registered in the Japan Registry of Clinical Trials (https://jrct.niph.go.jp) on January 14, 2020 as jRCTs071190042.