Benefit and a possible risk of tocilizumab therapy for adult-onset Still’s disease accompanied by macrophage-activation syndrome

Kawasaki Disease-Associated Cytokine Storm Syndrome

Kawasaki disease (KD) is a hyperinflammatory syndrome manifesting as an acute systemic vasculitis characterized by fever, nonsuppurative conjunctival injection, rash, oral mucositis, extremity changes, and cervical lymphadenopathy. KD predominantly affects young children and shares clinical features and immunobiology with other hyperinflammation syndromes including systemic juvenile idiopathic arthritis (sJIA) and multisystem inflammatory syndrome in children (MIS-C). Cytokine storm syndrome (CSS) is an acute complication in ~2% of KD patients; however, the incidence is likely underestimated as many clinical and laboratory features of both diseases overlap. CSS should be entertained when a child with KD is unresponsive to IVIG therapy with recalcitrant fever. Early recognition and prompt institution of immunomodulatory treatment can substantially reduce the mortality and morbidity of CSS in KD. Given the known pathogenetic role of IL-1β in both syndromes, the early use of IL-1 blockers in refractory KD with CSS deserves consideration.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

Efficacy of Baricitinib in Patients with Refractory Adult-Onset Still's Disease

BACKGROUND AND OBJECTIVE

Adult-onset Still's disease (AOSD) is an idiopathic systemic inflammatory disease of unknown aetiology. Some patients exhibit resistance to conventional treatment during long-term therapy. Janus kinase inhibitors (JAKinibs) may contribute to the improvement in AOSD symptoms via the JAK-signal transducer and activator of transcription (STAT) pathway. We aimed to explore the efficacy and safety of baricitinib in patients with refractory AOSD.

METHODS

Patients were enrolled if they fulfilled the Yamaguchi AOSD classification criteria in China between 2020 and 2022. All patients were recognized as having refractory AOSD and were treated with oral baricitinib at a dosage of 4 mg once daily. A systemic score and prednisone dosage were used to evaluate the efficacy of baricitinib at months 1, 3, and 6 and at the last follow-up visit. The safety profiles were recorded and analysed at every assessment.

RESULTS

Seven female patients with refractory AOSD received baricitinib. The median age was 31 (IQR 10) years. Treatment was terminated in one patient due to progressive macrophage activation syndrome (MAS). Others continued baricitinib treatment until the last assessment. The systemic score decreased significantly at 3 months (p = 0.0216), 6 months (p = 0.0007), and the last follow-up visit (p = 0.0007) compared with baseline. One month after the initiation of baricitinib, the rates of improvement in fever, rash, sore throat, and myalgia symptoms were 71.4% (5/7), 40% (2/5), 80% (4/5), and 66.7% (2/3), respectively. Five patients remained symptom-free at the last follow-up visit. In most patients, their laboratory values had returned to normal by the last follow-up visit. A significant reduction in the levels of C-reactive protein (CRP) (p = 0.0165) and ferritin (p = 0.0047) was observed at the last visit compared with baseline. The daily prednisolone dosage significantly decreased from 35.7 ± 15.1 mg/day at baseline to 8.8 ± 4.4 mg/day by month 6 (p = 0.0256), and it was 5.8 ± 4.7 mg/day at the last assessment (p = 0.0030). Leukopenia due to MAS was noted in one patient. Except for mild abnormalities in lipid parameters, no other severe adverse events occurred during follow-up.

CONCLUSIONS

Our findings suggest that baricitinib therapy could provide rapid and durable clinical and laboratory improvement in patients with refractory AOSD. Treatment seemed to be well tolerated by these patients. The long-term efficacy and safety of baricitinib therapy for AOSD should be assessed further in prospective controlled clinical trials in the future.

TRIAL REGISTRATION

Trial registration number (TRN): ChiCTR2200061599. Date of registration: 29 June 2022 (retrospectively registered).

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.

Fulminant elderly adult-onset Still disease effectively treated with tocilizumab and methotrexate: A case report

RATIONALE

Adult-onset Still disease (AOSD) is a rare inflammatory disease of unknown etiology. AOSD is common in young or middle-aged adults; however, in recent years, there have been increasing reports of elderly AOSD. Differentiating AOSD from diseases such as infections and malignancies is difficult. Moreover, rare fulminant AOSD cases with resistance to corticosteroids and immunosuppressive drugs have been reported.

PATIENT CONCERNS

An 80-year-old woman presented with flaccid fever, generalized arthralgia, and erythema of the anterior chest for 2 weeks. On day 5 of hospitalization, the patient developed pleural effusion with hypoxemia and her vital signs indicated rapid progression to shock. During the clinical course, the levels of inflammatory markers, including maximum level of ferritin and white blood cells (WBCs) were elevated (252,796 ng/mL and 86,500/μV, respectively) with disseminated intravascular coagulation syndrome (DIC) and macrophage activation syndrome (MAS).

DIAGNOSIS

The patient was diagnosed with elderly AOSD as per the Yamaguchi criteria for AOSD. The state of disease was extremely severe with rapid progression and was, thus, categorized as a fulminant form of elderly AOSD.

INTERVENTIONS

The patient was treated with prednisolone (PSL) pulse therapy (1000 mg/d) twice and plasma exchange in the intensive care unit for the primary disease and shock. Although she recovered from shock, she developed DIC and MAS. Methotrexate (MTX; 10 mg/d) improved the DIC and MAS. However, severe pleuritis recurred and the patient developed pericarditis; her primary disease was poorly controlled. Finally, tocilizumab (TCZ) was introduced using interleukin-18 (IL-18) as a surrogate marker. The IL-18 level was measured repeatedly following admission, with the peak level (170,000 pg/mL) recorded on the 75th day of hospitalization, immediately prior to introducing TCZ.

OUTCOMES

The combined use of MTX, TCZ, and PSL was effective in suppressing elderly AOSD, which was unsuccessfully controlled with MTX and PSL. Frequent monitoring of IL-18 levels proved useful for differentiating elderly AOSD from other diseases.

LESSONS

A fulminant form of elderly AOSD was treated with a combination of MTX, TCZ, and PSL. Repeated monitoring of IL-18 levels can be useful for decision-making in treating elderly AOSD.

Baseline clinical features predicting macrophage activation syndrome in patients with systemic adult-onset Still's disease receiving interleukin-6 inhibitor treatment

AIM

Macrophage activation syndrome (MAS), a severe complication of systemic adult-onset Still's disease (AOSD), has been reported to occur during interleukin-6 (IL-6) inhibitor treatment. However, predictors for MAS development are unknown. Therefore, this study investigated predictive features for MAS development after starting IL-6 inhibitor treatment in systemic AOSD patients.

METHOD

In a single-center retrospective study involving systemic AOSD patients who were refractory to high-dose glucocorticoids with immunosuppressants and started IL-6 inhibitor treatment between April 2008 and March 2020, we compared the baseline clinical features between patients who developed AOSD flare with MAS features (MAS group) and those who did not (non-MAS group) during IL-6 inhibitor treatment.

RESULTS

Only tocilizumab was used as an IL-6 inhibitor. Six of 14 refractory systemic AOSD patients developed AOSD flares with MAS features during tocilizumab treatment, including 4 who developed them shortly after initiation. The MAS group had significantly lower neutrophil counts, fibrinogen, and higher IL-18/C-reactive protein (CRP) ratio at starting tocilizumab (baseline) than the non-MAS group. Before starting tocilizumab, neutrophil counts were trending downward and upward in the MAS and non-MAS groups, respectively, with significant differences in changes. Receiver operating characteristic analysis showed that baseline neutrophil counts and fibrinogen and their changes before tocilizumab treatment and baseline IL-18/CRP ratio had significant discriminatory abilities for subsequent MAS development.

CONCLUSION

We identified baseline laboratory features associated with MAS development after initiating an IL-6 inhibitor in refractory systemic AOSD patients. These features may reflect the suppression of IL-6 signaling, and further suppression of IL-6 signaling might trigger early-onset MAS.

Associated factors with poor treatment response to initial glucocorticoid therapy in patients with adult-onset Still's disease

Background

High-dose glucocorticoids (GC) are first-line treatment for adult-onset Still’s disease (AOSD); however, some of the patients remain refractory to initial GC therapy, or rapidly relapse. The aim of this study was to identify prognostic factors for poor treatment response to initial GC therapy for AOSD.

Methods

Data on newly diagnosed AOSD patients were extracted from our database (n=71, mean age 51.6 years). The primary outcome was a poor treatment outcome at 4 weeks, which was defined as failure to achieve remission or relapse after achieving remission within 4 weeks, followed by administration of two or more rounds of GC pulse therapy or of any other immunosuppressive drugs.

Results

The initial mean dose ± standard deviation of prednisolone was 0.82 ± 0.23 mg/kg/day, and 34 (47.3%) patients received GC pulse therapy at week 0. Twenty-nine of 71 patients exhibited a poor treatment outcome at 4 weeks (40.8%). The second round of GC pulse therapy or immunosuppressive drugs was added in 17 or 24 of the 29 patients, respectively. These patients had higher baseline white blood cell (WBC) counts, serum ferritin levels, systemic feature score based on clinical symptoms (modified systemic feature score, mSFS), more hemophagocytic syndrome (HPS) over the 4 weeks, and the higher severity score based on modified Pouchot score or severity index of the Japanese Ministry of Health, Labour and Welfare, than the remaining 42 patients. Multivariable logistic regression model identified baseline WBC count as a prognostic factor for poor outcome (odds ratio per 1000/μl increment: 1.12, 95% CI 1.04–1.29), while thrombocytopenia, hyperferritinemia, and mSFS at baseline did not achieve statistical significance. Receiver-operating characteristic curve analysis showed that the optimal cut-off for WBC count was 13,050/μl. The Kaplan-Meier method showed the cumulative rate of poor treatment outcome to be 60.0% in patients with WBC ≥13,050/μl and 23.5% in those with WBC <13,050/μl.

Conclusions

A higher WBC count but not thrombocytopenia, hyperferritinemia, and mSFS at baseline was a significant prognostic factor for poor treatment outcome at week 4 in this retrospective cohort of AOSD patients. Our findings provide important information for determining the initial treatment strategy of newly-diagnosed AOSD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02780-3.

Macrophage activation syndrome in patients with adult-onset Still's disease under tocilizumab treatment: A single-center observational study

OBJECTIVES

Macrophage activation syndrome (MAS) developed under tocilizumab treatment poses a diagnostic challenge. This study aims to demonstrate the frequency and the clinical features of MAS developed in patients with adult-onset Still's disease (AOSD) receiving tocilizumab.

METHODS

The consecutive AOSD patients treated with tocilizumab in our institution from April 2008 to March 2020 were studied. The frequency of clinically diagnosed MAS during tocilizumab treatment, their conformity to the several criteria relevant for MAS, and laboratory characteristics compared to AOSD flare were investigated.

RESULTS

Of the 20 AOSD patients treated with tocilizumab, six developed clinically diagnosed MAS, four immediately after starting tocilizumab and two after long-term treatment. Some of them had already met the MAS criteria before starting tocilizumab. At MAS diagnosis, although some did not meet the MAS criteria due to lack of fever and/or the lower ferritin levels, all consistently showed sharp increases in ferritin along with marked abnormal changes in two or more different markers of organ damage, unlike the AOSD flares.

CONCLUSION

MAS is not a rare complication in AOSD patients receiving tocilizumab. The clinical similarities between systemic AOSD and MAS, and substantial alterations in MAS features by inhibition of interleukin-6 signaling may limit the utility of the existing diagnostic/classification criteria in diagnosing MAS under tocilizumab treatment. The emergence of abnormalities in MAS-related organ damage markers with a rapid elevation of ferritin should be considered as MAS development in AOSD patients receiving tocilizumab even if the patients are afebrile or have relatively low ferritin levels.

Treatment of Connective Tissue Disease-Related Intractable Disease with Biological Therapeutics

The treatment of connective tissue disease (CTD) and CTD-related intractable diseases (CTD-IDs) currently depends on the use of steroid therapy. Approximately 20 years have passed since the approval of infliximab for rheumatoid arthritis in 2003. Since then, several biological therapeutics have been marketed and adapted for many CTDs and CTD-IDs other than rheumatoid arthritis. Although conventional treatment for patients with these diseases is rarely used because of their poor prognosis, these cases may benefit from biological therapeutics. However, choosing biological therapeutics is difficult because they have different target molecules compared with conventional therapeutics. In this review, we address the current situation of biological therapeutics for CTD-IDs including Behcet's disease, psoriatic arthritis, ankylosing spondylitis, anti-neutrophil cytoplasmic antibody-related arthritis, and adult Still's disease, as well as the choice of biological therapeutics in clinical practice.

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.

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.

Immune cartography of macrophage activation syndrome in the COVID-19 era

A hyperinflammatory 'cytokine storm' state termed macrophage activation syndrome (MAS), culminating from a complex interplay of genetics, immunodeficiency, infectious triggers and dominant innate immune effector responses, can develop across disparate entities including systemic juvenile idiopathic arthritis (sJIA) and its counterpart adult-onset Still disease (AOSD), connective tissue diseases, sepsis, infection, cancers and cancer immunotherapy. Classifying MAS using the immunological disease continuum model, with strict boundaries that define the limits of innate and adaptive immunity, at one boundary is MAS with loss of immune function, as occurs in the 'perforinopathies' and some cases of sJIA-AOSD. Conversely, at the other boundary, immune hypersensitivity with gain of immune function in MHC class II-associated sJIA-AOSD and with chimeric antigen receptor (CAR) T cell therapy also triggers MAS. This provides a benchmark for evaluating severe inflammation in some patients with COVID-19 pneumonia, which cripples primary type I interferon immunity and usually culminates in a lung-centric 'second wave' cytokine-driven alveolitis with associated immunothrombosis; this phenomenon is generally distinct from MAS but can share features with the proposed 'loss of immune function' MAS variant. This loss and gain of function MAS model offers immune cartography for a novel mechanistic classification of MAS with therapeutic implications.

Adult-onset still's disease and treatment results with tocilizumab

AIMS

Adult-onset Still's disease (AOSD) is a rare and non-familial auto-inflammatory disorder. Increased levels of IL-6 and other pro-inflammatory cytokines have been shown in AOSD. To evaluate the efficacy and safety profile of tocilizumab (TCZ), an IL-6 receptor antagonist monoclonal antibody, in AOSD.

METHODS

Thirty-nine patients followed up with the diagnosis of AOSD between 2013 and 2019 were retrospectively evaluated and the 16 patients (10 Female/6 Male) treated with TCZ for refractory AOSD were included in the study group. Among the remaining 23 patients 16 had non-biological treatments and had no important complications at the presentation. TCZ was given to patients at a dose of 4-8 mg/kg every 4 weeks. Patients were evaluated after 3-6 months of TCZ treatment for side effects, inflammatory and clinical response and concomitant treatments.

RESULTS

In TCZ (+) patients, the majority were female (62.5%), the mean age at disease onset was 38.5 ± 17.9 (20-81) years, and the most common symptoms and signs were myalgia (81.3%), fever (81.3%) and skin eruptions (75%). There was no difference between TCZ (+) and TCZ (-) groups for age, sex and clinical presentations. There was a significant decrease in dose of prednisolone, sedimentation rate, leucocyte count, C-reactive protein and ferritin levels and improvement in all clinical complaints after TCZ treatment. There were no relapses during the treatment. Three patients are in remission and under follow-up without any treatment after cessation of TCZ (4 months-3 years). No exacerbation of disease yet seen in those patients.

CONCLUSIONS

TCZ is an effective and well-tolerated treatment option for treatment resistant AOSD and contributes to the glucocorticoid-sparing. Since TCZ is a new drug in the treatment of AOSD, further studies are needed to assess whether the complications reported during the treatment are because of TCZ or natural course of the disease or coincidental findings.

Efficacy of high-dose anakinra in refractory macrophage activation syndrome in adult-onset Still's disease: when dosage matters in overcoming secondary therapy resistance

Macrophage activation syndrome (MAS) is a severe, potentially fatal complication of rheumatic diseases. This case demonstrates the significant challenges and therapeutic considerations in adult-onset Still’s disease (AOSD) complicated with MAS at initial presentation, which will be discussed. MAS in our patient was refractory to the first-line therapy with high-dose corticosteroids, early administration of anakinra at a standard dosage and subsequent add-on treatments with cyclosporine A, IVIG, etoposides and tocilizumab. At 2 months after presentation, the patient was still critically ill with clinical, laboratory and histological signs of an active uncontrolled MAS. Notably, adoption of anakinra at a high dosage finally induced remission. This case confirms that adjusted dosage of anakinra is an effective therapeutic strategy in a severe AOSD-related MAS. It is tempting to speculate that anakinra at a high dosage, if used earlier, would have significantly changed the course of the disease in our patient and could have led to earlier remission.

Reintroduction of tocilizumab elicited macrophage activation syndrome in a patient with adult-onset Still's disease with a previous successful tocilizumab treatment

Macrophage activation syndrome (MAS) is a form of secondary hemophagocytic lymphohistiocytosis and is a rapidly progressive, life-threatening complication of adult-onset Still's disease (AOSD). An anti-IL-6 receptor monoclonal antibody, tocilizumab, has shown to be effective in the treatment of AOSD but may precipitate MAS in patients with AOSD. The precise mechanism of MAS developed during anti-cytokine biologic agents remains unknown, but selective inhibition of a subset of pathways could impact other immune signalling pathways and trigger MAS. We herein describe a case of AOSD with the opposite outcomes of tocilizumab therapy, remission and development of MAS, after tocilizumab treatment at the initial flare and the relapse. From the comparison of clinical characteristics and concomitant treatment around the time of starting tocilizumab in both flares, the type and intensity of concomitant immunosuppressive therapy might strongly affect MAS development during tocilizumab therapy.

Successful use of short-term add-on tocilizumab for refractory adult-onset still's disease with macrophage activation syndrome despite treatment with high-dose glucocorticoids, cyclosporine, and etoposide

Macrophage activation syndrome (MAS) is a form of secondary hemophagocytic lymphohistiocytosis (HLH) and is a life-threatening complication of adult-onset Still disease. MAS has been usually treated with high-dose glucocorticoid with additional immunosuppressive agents, such as cyclosporine. Etoposide has been used for the treatment of severe refractory MAS based on the successful results of HLH-2004 protocol in patients with mostly primary form of HLH. We herein describe a case of severe refractory MAS secondary to adult-onset Still disease in an elderly woman that inadequately responded to etoposide but remarkably responded to additional tocilizumab. Furthermore, short-term tocilizumab led her into remission and enabled tapering off glucocorticoids after 15 months. Tocilizumab may be effective for the treatment of refractory HLH after the failure of the etoposide-containing induction regimen.

Macrophage activation syndrome in adult dermatomyositis: a case-based review

Macrophage activation syndrome (MAS) is a severe and life-threatening syndrome associated with autoimmune diseases, characterized by fever, hepatosplenomegaly, and pancytopenia. Dermatomyositis (DM) is one of the causes of MAS; however, its clinical characteristics in DM patients remain unclear. This study aimed to present a case of anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive DM complicated by MAS in a 29-year-old woman and to review the literatures including similar cases. Even though symptoms and cytopenia of our patient were refractory to combination therapy, including glucocorticoids, immunosuppressants, and plasma exchange, the administration of rituximab (RTX) resulted in rapid clinical improvement and glucocorticoid reduction. The literature review revealed 18 adult patients with DM associated MAS. Most patients developed MAS within 3 months from DM onset. A monotherapy of glucocorticoid was insufficient to control the disease, and the mortality of MAS in DM was higher than that of MAS in other rheumatic diseases, despite being treated by various means. RTX may be an effective treatment for patients with DM complicated by MAS who are refractory to conventional therapy. Anti-MDA5 antibody could influence the development of MAS; however, further investigations are needed to elucidate the association between myositis-specific antibody and MAS.

Clinical and laboratory features, treatment, and outcomes of macrophage activation syndrome in 80 children: a multi-center study in China

BACKGROUND

Macrophage activation syndrome (MAS) is a major cause of morbidity and mortality in pediatric rheumatology. We aimed to further understand the clinical features, treatment, and outcome of MAS in China.

METHODS

A multi-center cohort study was performed in seven hospitals in China from 2012 to 2018. Eighty patients with MAS were enrolled, including 53 cases with systemic juvenile idiopathic arthritis (SJIA-MAS), 10 cases of Kawasaki disease (KD-MAS), and 17 cases of connective tissue disease (CTD-MAS). The clinical and laboratory data were collected before (pre-), at onset, and during full-blown stages of MAS. We compared the data among the SJIA-MAS, KD-MAS, and CTD-MAS subjects.

RESULTS

51.2% of patients developed MAS when the underlying disease was first diagnosed. In patients with SJIA, 22.6% (12/53) were found to have hypotension before the onset of SJIA-MAS. These patients were also found to have significantly increased aspartate aminotransferase (AST) and lactate dehydrogenase (LDH), as well as decreased albumin (P < 0.05), but no difference in alanine aminotransferase, ferritin, and ratio of ferritin/erythrocyte sedimentation rate (ESR) at onset of MAS when compared to pre-MAS stages of the disease. In addition, ferritin and ratio of ferritin/ESR were significantly elevated in patients at full-blown stages of SJIA-MAS compared to pre-MAS stage. Significantly increased ferritin and ratio of ferritin/ESR were also observed in patients with SJIA compared to in KD and CTD. Receiver-operating characteristic analysis showed that 12,217.5 μg/L of ferritin and 267.5 of ferritin/ESR ratio had sensitivity (80.0% and 90.5%) and specificity (88.2% and 86.7%), respectively, for predicting full-blown SJIA-MAS. The majority of the patients received corticosteroids (79/80), while biologic agents were used in 12.5% (10/80) of cases. Tocilizumab was the most commonly selected biologic agent. The overall mortality rate was 7.5%.

CONCLUSIONS

About half of MAS occurred when the underlying autoimmune diseases (SJIA, KD, and CTD) were first diagnosed. Hypotension could be an important manifestation before MAS diagnosis. Decreased albumin and increased AST, LDH, ferritin, and ratio of ferritin/ESR could predict the onset or full blown of MAS in patient with SJIA.

New Onset Autoimmune Disease or Macrophage Activation Syndrome?

Macrophage activation syndrome (MAS) is a potentially life-threatening condition that may complicate many pediatric rheumatologic diseases. Because of its similarity in presentation to other conditions with overlapping manifestations, such as flares of rheumatologic disease or systemic infection, and the fact that there exists no single pathognomonic clinical finding or laboratory parameter to aid in diagnosis, MAS presents a significant diagnostic challenge to the practicing pediatrician with limited access to consulting pediatric rheumatologists. Along with a review of the physiology and manifestations of the condition, we have included the most current consensus for diagnosing MAS. [Pediatr Ann. 2019;48(10):e395-e399.].

Macrophage activation syndrome complicating rheumatic diseases in adults: case-based review

Macrophage activation syndrome (MAS) is a life-threatening complication of rheumatologic diseases. Data regarding the clinical course, management and outcome of adults with MAS is limited. Therefore, we aimed to describe the clinical features, treatment and outcome of adult patients with MAS, and review the literature for previous cohorts. We retrospectively reviewed patients with MAS complicating rheumatologic diseases between the years 2007 and 2017. Through Pubmed, Medline and Scopus literature search we identified previous cases of adult patients with MAS. We identified 7 patients with MAS complicating rheumatologic diseases (5 females and 2 males). The median age of diagnosis was 32 (range 26-57) years. The median follow-up was 30 months (range 6.95-36.5) months. The underlying rheumatologic disease was adult onset Still's disease (AOSD) in 3 patients, systemic juvenile idiopathic arthritis (sJIA) in 2 patients, systemic lupus erythematosus (SLE) in 1 patient, and systemic vasculitis in 1 patient. Four patients developed MAS concurrently with the clinical development of the rheumatologic disease. All the patients were treated with systemic corticosteroids. Five patients were treated with cyclosporine A, one of which received combination therapy with anakinra, and one received tocilizumab. Two patients deceased during the hospitalization. We identified 92 patients from literature cohorts, 73 (79%) of them with AOSD. MAS developed concurrently with the underlying rheumatologic disease in 25 (27%) patients, and 30 (33%) patients deceased. Our cohort and previous cohorts demostrate that MAS often presents concurrently with the underlying rheumatologic disease and is associated with a high mortality rate. Further larger prospective studies are needed to determine the optimal management of MAS.

Successful treatment of macrophage activation syndrome complicating adult-onset Still’s disease with tocilizumab: a case report

We report a case of 50-year-old female patient with adult-onset Still’s disease (AOSD) complicated by macrophage-activation syndrome (MAS). After initial control of the disease with high-dose parenteral corticosteroids, tocilizumab (TCZ) therapy aided in maintaining the remission with rapid tapering of steroid dose. TCZ may be useful for MAS complicating AOSD.

A Pilot Study on Tocilizumab for Treating Refractory Adult-Onset Still's Disease

To investigate the efficacy and safety of Tocilizumab (TCZ) in patients with refractory adult-onset Still’s disease (AOSD). We enrolled 8 female patients from October 2013 to July 2014. All patients fulfilled Japan’s Yamaguch AOSD classification and recognized as refractory AOSD. All Patients received TCZ treatment 4–8 mg/kg every 4 weeks. Evaluation of efficacy was conducted after 3 months and 6 months, including clinical manifestations of AOSD patients, improvement of inflammatory markers as well as glucocorticoids dosage adjustments. Treatment-related adverse events were also recorded. Patients treated with Tocilizumab with average age 41.1 years old, the average disease duration 23.6 months. Two patients drop off due to infusion side effects. Others were followed at least 6 months. After 3 months of follow-up, remission rates of fever, arthritis and rashes from 8 patients were 87.5%, 100% and 87.5%. White blood cell counts, erythrocyte sedimentation rate, C-reactive protein and ferritin levels were decreased (P < 0.01) significantly compared to treatment before. Furthermore, the average dose of prednisone was reduced from 51.7 ± 38.4 mg/d to 12.9 ± 7.7 mg/d (P < 0.01). Our findings suggest that tocilizumab could alleviate the clinical manifestations of refractory AOSD rapidly and efficiently.

Advances in immunopathogenesis of macrophage activation syndrome during rheumatic inflammatory diseases: toward new therapeutic targets?

INTRODUCTION

Macrophage activation syndrome (MAS) is a severe, hyperinflammatory life-threatening syndrome, generally complicating different rheumatic diseases. Despite the severity of the disease, little is known about the pathogenic mechanisms and, thus, possible targeted therapies in the management of these patients. Areas covered: In this review, we aimed to update the current pathogenic knowledge of MAS, during rheumatic diseases, focusing mainly on immunologic abnormalities and on new possible therapeutic strategies. Expert commentary: The difficult pathogenic scenario of MAS, in which genetic defects, predisposing diseases, and triggers are mixed together with the high mortality rate, make it difficult to manage these patients. Although most efforts have been focused on investigating the disease in children, in recent years, several studies are trying to elucidate the possible pathogenic mechanism in adult MAS patients. In this context, genetic and immunological studies might lead to advances in the knowledge of pathogenic mechanisms and possible new therapeutic targets. In the future, the results of ongoing clinical trials are awaited in order to improve the management and, thus, the survival of these patients.

Biologics in juvenile idiopathic arthritis: a narrative review

In the past years, pediatric rheumatology has seen a revolution in the treatments for rheumatic diseases, particularly juvenile idiopathic arthritis. Even if nonsteroidal anti-inflammatory drugs (NSAID), intra-articular corticosteroids (IAC) injections, and methotrexate remain the mainstay of the treatment for JIA patients, in aggressive disease, these treatments may be not sufficient to reach disease remission and to prevent long-term disability. Comprehension of immunological mechanisms involved in the pathogenesis of the diseases allowed to conceive new drugs targeting specific steps of the immune response. Several cytokines, like TNF alpha and IL-1, represent a very interesting target for biologic therapies. Due to the efficacy of these therapies, nowadays, "disease remission" in pediatric rheumatology is more and more frequent, especially in juvenile idiopathic arthritis patients, and the long-term outcomes have been significantly improved. Crucial to these advancements have been multicenter controlled clinical trials and long-term safety monitoring.

CONCLUSIONS

Research in pediatric rheumatology has resulted in dramatic advances in diseases management. Biologic treatments have improved physical and functional outcomes and quality of life of patients with rheumatic disease. What is Known: • NSAID, intra-articular injection of corticoids, and methotrexate are the mainstay in treatment of JIA. • In aggressive JIA, these treatments may be not sufficient to reach disease remission and to prevent long term disability. What is New: • In recent years, management of JIA has significantly improved with the development of biologic therapies that allowed children with arthritis to reach a normal growth and to achieve a good long-term functional outcome.

How I treat patients with adult onset Still's disease in clinical practice

Adult onset Still's disease (AOSD) is a rare systemic inflammatory disease of unknown etiology characterized by four cardinal signs which are almost always present in patients: high spiking fever, arthralgia (with or without synovitis), maculo-papular salmon-pink evanescent skin rash, striking leukocytosis with neutrophilia. Here, we review the clinical features of AOSD and describe the best practice approaches for its management, reviewing available guidelines and recommendations and providing experts' insights.

Treatment of adult-onset still's disease: up to date

INTRODUCTION

Adult onset Still's disease (AOSD) is a systemic inflammatory disorder of unknown etiology, and approximately 60-70% of patients may develop a chronic polyphasic form of the disease or a chronic polyarthritis. Due to rarity of disease, treatment of AOSD is not based on controlled study, but on case based experiences. Areas covered: Recently, the application of anti-cytokine therapy based on pathophysiology has resulted in significant progress in the treatment of AOSD. Here, we review current knowledge of the pathogenesis, disease progression, currently available biomarkers of disease activity, standard therapeutic agents, utility of biologic agents, future perspectives for treatment and treatment of macrophage activation syndrome. Expert commentary: Accumulated clinical data suggest that chronic disease can be classified into two subsets: dominant systemic disease, and the arthritis subgroup. IL-1 inhibitors may be more efficient for systemic manifestations and IL-6 inhibitor for both joint involvement and systemic manifestations. TNF inhibitors must be reserved for patients with purely chronic articular manifestations. For ideal management of patients, it is very important to measure disease activity accurately during follow up, but no single biomarker has been classified as ideal. New therapeutic agents and composite biomarkers are needed to improve the outcome of patients with AOSD by identifying disease activity properly.

[Interleukin-6 inhibition as a potential therapeutic target in rheumatic diseases]

As a pro-inflammatory cytokine, the 21-kDa glycoprotein interleukin-6 (IL-6) plays a crucial role in the initiation of acute inflammation, as well in the perpetuation of a chronic inflammatory immune response. Thus, IL-6 might be involved in the pathogenesis of various autoimmune diseases. So far, the IL-6-rezeptor-antibody tocilizumab (TCZ, RoActemtra®) is the only approved drug for the treatment of IL-6-mediated disease, including rheumatoid arthritis (RA), systemic juvenile idiopathic (sJIA) and polyarticular juvenile arthritis (pJiA), as well as Castleman's disease (in Japan only). In recent years, an emerging number of case reports and small uncontrolled case series have reported on the successful treatment of various other chronic inflammatory diseases, which has resulted in the idea of a broad therapeutic potential for IL-6 blockade. Numerous IL-6 targets are currently in phase II/III study programs for RA as well as for other indications. This review focuses on the development of tocilizumab and other IL-6 targets as a therapeutic option for various diseases in rheumatology.

Adult-onset Still's disease: Advances in the treatment

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disorder mainly characterized by persistent high spiking fevers, evanescent rash, and joint involvement. The pathogenesis of AOSD is only partially known, but pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-6, IL-18, and IFN-γ seem to play a major role in this disorder. AOSD is at the crossroad of auto-inflammatory syndromes and autoimmune diseases. It is diagnosed by exclusion to determine the presence of high serum ferritin levels, which is usually >1000 μg/L. AOSD is generally treated with non-steroidal anti-inflammatory drugs, corticosteroids, and disease-modifying anti-rheumatic drugs (DMARDs). Although information on biologic therapy in the management of AOSD is scarce, these drugs represent a major breakthrough in the management of patients with AOSD refractory to corticosteroids or conventional DMARDs or in patients presenting life-threatening manifestations. In this regard, TNF-α, IL-1, and IL-6 antagonists had been proved effective in patients with AOSD.

Understanding the spectrum of haemophagocytic lymphohistiocytosis: update on diagnostic challenges and therapeutic options

The cytokine storm syndrome 'haemophagocytic lymphohistiocytosis' (HLH) is an under-recognized hyperinflammatory disorder, causing high morbidity and mortality risk in children and adults. It can be subdivided into a primary, genetic form and a secondary, acquired form that complicates diverse infections, malignancies and autoimmune or autoinflammatory disorders. Both subtypes present with the same spectrum of non-specific symptoms, making accurate diagnosis and rapid treatment initiation challenging. In the last decade, increased awareness and international collaborative efforts fuelled a marked progress in diagnostic protocols and novel treatment strategies for HLH and new diagnostic guidelines are being tailored to specific secondary HLH subtypes. Therapy is gradually shifting its focus from overall immunosuppression towards targeting specific cytokines, cell types or signalling pathways underlying pathophysiology. Nevertheless, continued research efforts remain indispensable to customize therapy to individual patient needs.

Rate and Clinical Presentation of Macrophage Activation Syndrome in Patients With Systemic Juvenile Idiopathic Arthritis Treated With Canakinumab

OBJECTIVE

In pivotal trials, canakinumab has been shown to be effective in the treatment of systemic juvenile idiopathic arthritis (JIA), but reported adverse events have included macrophage activation syndrome (MAS). This study was undertaken to assess the impact of canakinumab on MAS incidence.

METHODS

An independent MAS Adjudication Committee (MASAC), consisting of 3 of the authors, was convened, and a search of databases from clinical studies of canakinumab treatment in systemic JIA was performed using MASAC-specified adverse event terms to identify potential MAS events. These were then adjudicated as "probable MAS," "possible MAS," or "MAS unlikely," using criteria developed by the MASAC. MAS rates were expressed as numbers of cases per 100 patient-years.

RESULTS

Of 72 potential MAS cases identified, 21 events (19 with canakinumab treatment; 2 with placebo treatment) in 19 patients were adjudicated as being probable MAS and 10 events in 9 patients as being possible MAS. Systemic JIA was well controlled in the majority of canakinumab-treated patients at the time of MAS. The time period between initiation of canakinumab treatment and onset of MAS ranged from 3 to 1,358 days (median 292 days). When the rates of probable MAS events were compared between canakinumab-treated patients (2.8 per 100 patient-years) and placebo-treated patients (7.7 per 100 patient-years), the difference was not significant (-4.9 [95% confidence interval -15.6, 5.9]). There were 3 deaths due to MAS-related complications (2 in patients receiving canakinumab; 1 in a patient receiving placebo); full recovery was reported in all other patients. Infections were the most common trigger of MAS, and the clinical features of MAS were not modified by canakinumab.

CONCLUSION

Canakinumab does not have a significant effect on MAS risk or its clinical features in patients with systemic JIA. Infections are the most common trigger, and MAS occurs even in patients whose systemic JIA is well controlled with this treatment.

Macrophage activation syndrome in the era of biologic therapy

Macrophage activation syndrome (MAS) refers to acute overwhelming inflammation caused by a 'cytokine storm'. Although increasingly recognized as a life-threatening complication of various rheumatic diseases, clinically, MAS is strikingly similar to primary and secondary forms of haemophagocytic lymphohistiocytosis (HLH). Not surprisingly, many rheumatologists prefer the term secondary HLH rather than MAS to describe this condition, and efforts to change the nomenclature are in progress. The pathophysiology of MAS remains elusive, but observations in animal models, as well as data on the effects of new anticytokine therapies on rates and clinical presentations of MAS in patients with systemic juvenile idiopathic arthritis (sJIA), provide clues to the understanding of this perplexing clinical phenomenon. In this Review, we explore the latest available evidence and discuss potential diagnostic challenges in the era of increasing use of biologic therapies.

Macrophage Activation Syndrome

Macrophage activation syndrome (MAS) is a potentially life-threatening complication of rheumatic disorders that occurs most commonly in systemic juvenile idiopathic arthritis. In recent years, there have been several advances in the understanding of the pathophysiology of MAS. Furthermore, new classification criteria have been developed. Although the place of cytokine blockers in the management of MAS is still unclear, interleukin-1 inhibitors represent a promising adjunctive therapy, particularly in refractory cases.

Infection is the major trigger of hemophagocytic syndrome in adult patients treated with biological therapies

INTRODUCTION

Hemophagocytic syndromes (hemophagocytic lymphohistiocytosis, HLH) are characterized by a wide range of etiologies, symptoms, and outcomes, but have a common etiopathogenic pathway leading to organ damage: an excessive inflammatory response. Biological therapies have been proposed as a therapeutic option for refractory HLH, but have also been related to the development of HLH in severe immunosuppressed patients.

OBJECTIVES AND METHODS

The purpose of this study was to analyze the clinical characteristics and outcomes of adult patients who developed HLH after receiving biological therapies.

RESULTS

We identified 30 patients (29 from the PubMed search and one unpublished case), including 19 women and 11 men, with a mean age of 46.5 years. Underlying diseases consisted of rheumatologic/autoimmune diseases in 24 patients and hematological neoplasia in the remaining 6. Biological agents received before the development of HLH were mainly anti-TNF agents (n = 19). Search for microorganisms confirmed systemic infection in 20 (67%) patients, including Mycobacterium tuberculosis (n = 5), cytomegalovirus (CMV) (n = 4), Epstein-Barr virus (EBV) (n = 3), Histoplasma capsulatum (n = 3), Escherichia coli (n = 2), Staphylococcus aureus, Leishmania amastigotes and Brucella melitensis (n = 1, respectively); viral infections were mainly reported in inflammatory bowel disease (IBD) patients. Patients with infections had more frequently received previous immunosuppressive therapies (p = 0.036) and had lower leukocyte counts (p = 0.020) in comparison with patients without associated infections. The outcome was described in 29 patients. After a mean follow-up of 6.3 months, 8 patients died (28%) and 6 had received anti-TNF agents. There was a high mortality rate in patients aged >65 years and those with tuberculosis (62% and 60%, respectively).

CONCLUSIONS

In patients receiving biological therapies who develop HLH, searching for a concomitant infectious process is mandatory, and specific surveillance for EBV/CMV infections (in patients with IBD) and for bacteria, including mycobacteria (in elderly patients receiving anti-TNF therapy), is recommended.

Monogenic autoinflammatory diseases: Cytokinopathies

Rapid advances in genetics are providing unprecedented insight into functions of the innate immune system with identification of the mutations that cause monogenic autoinflammatory disease. Cytokine antagonism is profoundly effective in a subset of these conditions, particularly those associated with increased interleukin-1 (IL-1) activity, the inflammasomopathies. These include syndromes where the production of IL-1 is increased by mutation of innate immune sensors such as NLRP3, upstream signalling molecules such as PSTPIP1 and receptors or downstream signalling molecules, such as IL-1Ra. Another example of this is interferon (IFN) and the interferonopathies, with mutations in the sensors STING and MDA5, the upstream signalling regulator AP1S3, and a downstream inhibitor of IFN signalling, ISG15. We propose that this can be extended to cytokines such as IL-36, with mutations in IL-36Ra, and IL-10, with mutations in IL-10RA and IL-10RB, however mutations in sensors or upstream signalling molecules are yet to be described in these instances. Additionally, autoinflammatory diseases can be caused by multiple cytokines, for example with the activation of NF-κB/Rel, for which we propose the term Relopathies. This nosology is limited in that some cytokine pathways may be degenerate in their generation or execution, however provides insight into likely autoinflammatory disease candidates and the cytokines with which newly identified mutations may be associated, and therefore targeted.

Macrophage activation syndrome with acute hepatitis E during tocilizumab treatment for rheumatoid arthritis

Tocilizumab is a humanized antibody against the membrane and soluble receptors for interleukin-6. Tocilizumab is among the disease-modifying antirheumatic drugs (DMARDs) used to treat moderate-to-severe active rheumatoid arthritis (RA) refractory to conventional DMARDs. We report a case of macrophage activation syndrome that complicated acute hepatitis E and started within 24hours after the fourth tocilizumab infusion in a patient with RA.

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

Adult-onset Still's disease (AOSD), a systemic inflammatory disorder, is often considered a part of the spectrum of the better-known systemic-onset juvenile idiopathic arthritis, with later age onset. The diagnosis is primarily clinical and necessitates the exclusion of a wide range of mimicking disorders. AOSD is a heterogeneous entity, usually presenting with high fever, arthralgia, skin rash, lymphadenopathy, and hepatosplenomegaly accompanied by systemic manifestations. The diagnosis is clinical and empirical, where patients are required to meet inclusion and exclusion criteria with negative immunoserological results. There are no clear-cut diagnostic radiological or laboratory signs. Complications of AOSD include transient pulmonary hypertension, macrophage activation syndrome, diffuse alveolar hemorrhage, thrombotic thrombocytopenic purpura and amyloidosis. Common laboratory abnormalities include neutrophilic leukocytosis, abnormal liver function tests, and elevated acute-phase reactants (ESR, CRP, ferritin). Treatment consists of anti-inflammatory medications. Non-steroidal anti-inflammatory drugs have limited efficacy, and corticosteroid therapy and disease-modifying anti-rheumatic drugs are usually required. Recent advances have revealed a pivotal role of proinflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1, IL-6, IL-8, and IL-18 in disease pathogenesis, giving rise to the development of novel targeted therapies aiming at optimal disease control. The review aims to summarize recent advances in pathophysiology and potential therapeutic strategies in AOSD.

Increased level of H-ferritin and its imbalance with L-ferritin, in bone marrow and liver of patients with adult onset Still's disease, developing macrophage activation syndrome, correlate with the severity of the disease

In this paper, we aimed to evaluate the levels of ferritin enriched in H subunits (H-ferritin) and ferritin enriched in L subunits (L-ferritin) and the cells expressing these 2 molecules, in the bone marrow (BM) and liver biopsies obtained from adult onset Still's disease (AOSD) patients who developed macrophage activation syndrome (MAS), and correlating these data with the severity of the disease. Twenty-one patients with MAS-associated AOSD underwent BM biopsy and among them, 9 patients with hepatomegaly and elevated liver enzymes underwent liver biopsy. All the samples were stained by both immunohistochemistry and immunofluorescence. A statistical analysis was performed to estimate the possible correlation among both H-ferritin and L-ferritin tissue expression and the clinical picture of the disease. Furthermore, the same analysis was performed to evaluate the possible correlation among the number of CD68/H-ferritin or CD68/L-ferritin positive cells and the clinical picture. Both immunohistochemical and immunofluorescence analysis demonstrated an increased tissue H-ferritin expression, in the BM and liver samples of our patients. This increased expression correlated with the severity of the disease. An inflammatory infiltrate, enriched in CD68 macrophages, expressing H-ferritin was observed in both the BM and the liver samples of our patients. Furthermore, we observed, that this increased number of CD68/H-ferritin positive cells significantly correlated with the severity of clinical picture and this specific BM infiltrate correlated with the mortality rate, reported in our cohort. Our data showed an imbalance between the levels of H- and L-ferritin in different organs of patients with MAS-associated AOSD and the evidence of a strong infiltrate of CD68/H-ferritin positive cells in the same organs. Furthermore, a strong correlation among both the tissue H-ferritin and the CD68/H-ferritin positive cells and the clinical picture was observed.

Two cases of adult-onset Still's disease treated with tocilizumab that achieved tocilizumab-free remission

There have been many previously reported cases of adult-onset Still's disease (AOSD) which were successfully treated with tocilizumab (TCZ). However, the efficacy and safety of TCZ therapy for AOSD-associated macrophage activation syndrome (MAS), and the optimal duration of TCZ therapy, remain unclear. We herein report two cases of refractory AOSD, one of which was associated with MAS. These two patients were treated with TCZ, and the withdrawal of TCZ was planned according to the serum interleukin-6 level, which resulted in TCZ-free remission.