Macrophage activation syndrome associated with adult-onset Still's disease: a multicenter retrospective analysis

Macrophage Activation Syndrome: Not Just for Rheumatologists Anymore

SYNOPSIS

Macrophage activation syndrome (MAS) is a term that was originally used to describe a hyperinflammatory syndrome that developed in some patients with rheumatologic diseases. It is now clear that MAS and hemophagocytic lymphohistiocytosis (HLH) are defined by the same core pattern of clinical symptoms and share an underlying pathophysiology of impaired cytolytic activity and IFNγ-driven cytokine storm. Given that these disorders are highly related, lessons learned from the management of MAS can provide insights into effective approaches for HLH, particularly the strategy to employ anti-cytokine therapies early in the disease course.

Tofacitinib as a possible treatment in macrophage activation syndrome: a pilot single-center study in China

OBJECTIVES

Our pilot study investigated the efficacy and safety of tofacitinib (TOF) in patients with macrophage activation syndrome (MAS), providing a new therapeutic option.

METHODS

This was a historical comparator, single-center study. Patients enrolled in our study were screened using the 2016 Pediatric Rheumatology International Trials Organization (PRINTO) criteria of MAS. MAS patients deemed suitable for TOF therapy were enrolled in the experimental group. The control group included MAS patients from Yantai Yuhuangding Hospital who had received biological and/or conventional synthetic disease-modifying anti-rheumatic drugs (b/csDMARDs) treatment in a similar period. Clinical characteristics, laboratory test results, MAS treatment response rates, and glucocorticoid discontinuation rates were compared between the two groups before and after treatment. Serious adverse events such as thrombosis or severe infection were recorded.

RESULTS

A total of 36 MAS patients were included-17 in the TOF treatment group and 19 in the b/csDMARDs control group. Baseline demographic and clinical characteristics were comparable between groups. After six weeks, the proportion of febrile patients was significantly lower in the TOF group compared to the control group (11.8% [2/17] vs. 47.3% [9/19], P = 0.021). Significant reductions were also observed in C-reactive protein levels at week 6 (5.9% [1/17] vs. 36.8% [7/19], P = 0.026) and ferritin levels at week 12 (100.0% [17/17] vs. 26.3% [5/19], P = 0.023). The MAS treatment response rate was significantly higher in the TOF group at weeks 2 and 6 (P = 0.029 and P = 0.023, respectively). Glucocorticoid discontinuation was more frequent in the TOF group, with a 12-week discontinuation rate of 100.0% (17/17) compared to 57.9% (11/19) in the control group (P = 0.002). No serious adverse events, including thrombosis or severe infections, were reported.

CONCLUSION

Our results suggest that TOF may be as effective as or even better than b/csDMARDs, with a quicker and higher response rate in patients with MAS without severe adverse events. Key Points •Tofacitinib may be as effective or better than b/csDMARDs in MAS. •Tofacitinib may act at a quicker and higher response rate in MAS. •Tofacitinib might be an alternative therapeutic option for patients with MAS.

Macrophage Activation Syndrome in Adult-Onset Still's Disease: Challenges in Early Detection and Management

Adult-onset Still's disease (AOSD) is an immunological disorder that manifests with fever, evanescent rash, leukocytosis, and arthralgia. One of the most severe complications of AOSD is macrophage activation syndrome, a life-threatening complication characterized by hyperactivation of the immune system and multiorgan dysfunction. This case report describes a 24-year-old female who developed macrophage activation syndrome in the setting of AOSD. Initially, she developed heterogeneous and nonspecific symptoms of fever, pharyngitis, rash, lymphadenopathy, and migratory arthralgia after a trip to Mexico. Thus, the diagnosis and appropriate treatment were delayed. Although her symptoms were temporarily relieved with oral steroids, she worsened clinically. She developed a widespread rash, persistent fever, a very high ferritin level (29,972 ng/mL), and elevated liver enzymes with mild hepatosplenomegaly, raising concern for macrophage activation syndrome. After ruling out infections, she was diagnosed with AOSD, and treatment with intravenous steroids was started, resulting in clinical improvement. Macrophage activation syndrome is a rare but fatal complication. Early recognition, particularly with elevated ferritin, liver dysfunction, and thrombocytopenia, is very important. Early intervention with glucocorticoids and biologics like anakinra is crucial for improving outcomes. The patient is in remission with ongoing follow-up with rheumatology.

Identification of novel cytokine to judge the diagnosis and clinical phenotype of adult-onset Still's disease

This study aimed to identify biomarkers to distinguish adult-onset Still's disease (AOSD) and to predict disease phenotypes. In total, 49 patients diagnosed with AOSD and 200 patients with common diseases (controls) were included in the analysis. The levels of 69 cytokines were analyzed using a multi-suspension cytokine array. Cytokine cluster analysis was performed to identify specific molecular networks. Furthermore, random forest analysis and logistic regression analysis were used to rank cytokines based on their importance and to determine specific biomarkers for identification of AOSD patients and phenotypes. Patients with AOSD demonstrated significantly higher macrophage migration inhibitory factor (MIF) and interleukin (IL)-12(p40) serum levels than controls and patients with rheumatoid arthritis. Serum levels of chemokine (C-C motif) ligand (CCL) 8 and CCL22 were significantly lower in AOSD patients with a polycyclic systemic disease phenotype and could be differentiated with high accuracy from the other phenotypes (cutoff value for CCL8 = 122.7 pg/mL, CCL22 = 593.3 pg/mL, sensitivity 66.7%, specificity 87.1%, area under the curve 0.843). Combined MIF and IL-12(p40) levels may represent a biomarker for differentiating patients with AOSD from those with other diseases. The chemokine profiles of AOSD with a polycyclic systemic disease phenotype may differ from other phenotypes.

Nationwide Analysis of Adult-Onset Still Disease With and Without Hemophagocytic Lymphohistiocytosis

INTRODUCTION

Adult-onset Still disease (AOSD) is a rare inflammatory condition with a monophasic, intermittent, or chronic clinical course, and a subset may experience life-threatening complications such as hemophagocytic lymphohistiocytosis (HLH). This study aims to characterize concurrent AOSD and HLH and identify variables independently associated with in-hospital death.

METHODS

We performed a medical records review of AOSD with and without HLH from the 2016-2019 National Inpatient Sample database. We performed a multivariable logistic regression analysis for in-hospital death. Results were reported as adjusted odds ratios (OR adj ).

RESULTS

There were 5495 hospitalizations with AOSD, of which 340 (6.2%) had HLH. Thirty (9.0%) of the combined AOSD and HLH group died in the hospital compared with 75 (1.5%) of those without HLH. Multivariable analysis in AOSD inpatients showed that disseminated intravascular coagulation (OR adj 6.13), hepatic failure (OR adj 7.16), infection (OR adj 3.72), respiratory failure (OR adj 6.89), and thrombotic microangiopathy (OR adj 14.05) were associated with higher odds of death. However, HLH itself was not an independent predictor of mortality in AOSD population.

CONCLUSIONS

HLH occurred in a small minority of inpatients with AOSD. HLH itself was not an independent risk factor for in-hospital death. Disseminated intravascular coagulation, hepatic failure, infection, respiratory failure, and thrombotic microangiopathy were associated with higher odds of in-hospital death in AOSD. Better awareness of these life-threatening complications may improve hospital outcomes.

Persistent Pruritic Linear Streaks of Adult-Onset Still's Disease: Reconsidering the Yamaguchi Criteria

Objective Adult-onset Still's disease (AOSD) is a rare orphan disease, the diagnosis of which remains challenging. This study aimed to identify additional clues for establishing early diagnosis beyond the existing criteria. Methods A retrospective longitudinal cohort study was conducted at two community hospitals in Japan between March 2012 and December 2022. The clinical characteristics and medical histories of patients with AOSD were extracted from the clinical records. The primary outcome was to identify the key manifestations of AOSD for an early diagnosis beyond the existing criteria. Results Twenty-one patients (mean age, 58 years) were included in the study. Fever was the first symptom in 13 out of 21 patients (62%). Six out of 21 patients (29%) presented with a pruritic rash only, while two out of 21 (10%) initially presented with a sore throat. All patients visited more than one medical institution. The median time to reach a correct diagnosis was 41 days (IQR 19-138). Nineteen out of 20 patients (95%) exhibited a pruritic rash, identified as persistent pruritic linear streaks, with a median duration of 21 days (IQR 12-64) before the diagnosis of AOSD as a cutaneous manifestation. Conclusions Persistent pruritic linear streaks were a key feature in the context of an early diagnosis of AOSD, offering an option for reconsidering and revising the existing classification criteria.

Neutrophil extracellular trap-induced intermediate monocytes trigger macrophage activation syndrome in adult-onset Still's disease

BACKGROUND

Adult-onset Still's disease (AOSD) is a systemic autoinflammatory disease characterized by innate immune system activation, with a high risk for macrophage activation syndrome (MAS). MAS development is associated with monocyte/macrophage activation and cytokine storm. Monocytes consist of three different subsets, classical monocytes (CMs, CD14brightCD16 -), intermediate monocytes (IMs, CD14brightCD16 +), and non-classical monocytes (NCMs, CD14dimCD16 +), each has distinct roles in inflammatory regulation. However, the frequencies and regulatory mechanism of monocyte subsets in AOSD patients have not been identified.

METHODS

We performed flow cytometry, RNA sequencing, phagocytosis analysis, and enzyme-linked immunosorbent assay to evaluate monocyte subsets, cell functions, and potential biomarkers. The effect of neutrophil extracellular traps (NETs) on monocytes was determined by evaluating mRNA levels of DNA sensors, surface CD16 expression, and inflammasome pathway activation.

RESULTS

Higher proportions of intermediate monocytes (IMs) were identified in active AOSD patients. IMs displayed higher expression of CD80, CD86, HLA-DR, and CD163 than CMs and NCMs. CD163 upregulation was noted on AOSD IMs, accompanied by increased phagocytic activity and elevated cytokine/chemokine production, including IL-1β, IL-6, CCL8, and CXCL10. The frequencies of IMs were correlated with disease activity and higher in AOSD patients with MAS (AOSD-MAS). CCL8 and CXCL10 were highly expressed in RNA sequencing of monocytes from AOSD-MAS patients and plasma CXCL10 level could serve as a potential biomarker for AOSD-MAS. Moreover, DNA-sensing pathway was activated in monocytes from AOSD-MAS patients. Stimulation with NETs derived from AOSD induced DNA sensor expression, the expansion of IMs, and inflammasome pathway activation. These effects can be abrogated by DNase I treatment.

CONCLUSIONS

Our results demonstrated that the proportions of IMs were elevated in AOSD and associated with MAS. The DNA component in NETs from AOSD plays an important role in the formation of IMs, shedding new light for the therapeutic target.

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).

Proposal of a new diagnostic algorithm for adult-onset Still's disease

OBJECTIVE

This study was performed to develop a new diagnostic algorithm for adult-onset Still's disease (AOSD).

METHODS

We conducted a multicenter prospective nationwide case-control study in tertiary Internal Medicine, Rheumatology, and Infectious Diseases departments, to include successively patients with suspected AOSD based on the presence of two or more major criteria of Yamaguchi and/or Fautrel classifications. Patients were classified as AOSD or controls according to a predefined procedure. A receiving operating characteristic curve was used to determine the best cutoff value of the points-based score for disease classification. A diagnostic algorithm was developed to help the physician in the diagnostic approach.

RESULTS

A total of 160 patients were included, 80 patients with AOSD and 60 controls with different diagnoses. Twenty patients with incomplete data were excluded. In the multivariate analysis, 6 items remained independently associated with AOSD diagnosis: typical rash (OR: 24.01, 3 points), fever ≥ 39 °C (OR: 17.34, 3 points), pharyngitis (OR: 10.23, 2 points), arthritis (OR: 9.01, 2 points), NLR ≥ 4 (OR: 11.10, 2 points), and glycosylated ferritin ≤ 20% (OR: 1.59, 1 point). AOSD should be considered if the patient satisfies 7 points with a sensitivity of 92.5%, specificity of 93.3%, and accuracy of 92.8% (area under the curve (AUC): 0.97 [95% CI: 0.94-0.99]). The present points-based score was more accurate and sensitive than the Yamaguchi classification (78.8%, 92.5%, p = 0.01) and Fautrel classification (76.3%, 92.5%, p = 0.004). A typical rash associated with a points-based score ≥ 7 points leads to a very likely disease.

CONCLUSION

The proposed new algorithm could be a good diagnostic tool for adult-onset Still's disease in clinical practice and research. Key Points • A diagnostic algorithm was performed to help the physician in the diagnostic approach of AOSD. • The points-based score included in this algorithm had a high sensitivity and accuracy. • This diagnostic algorithm can be useful in the clinical research.

Dermatologic Manifestations of Noninflammasome-Mediated Autoinflammatory Diseases

Autoinflammatory diseases (AIDs) arise from disturbances that alter interactions of immune cells and tissues. They give rise to prominent (auto)inflammation in the absence of aberrant autoantibodies and/or autoreactive T cells. AIDs that are predominantly caused by changes in the inflammasome pathways, such as the NLRP3- or pyrin-associated inflammasome, have gained substantial attention over the last years. However, AIDs resulting primarily from other changes in the defense system of the innate immune system are less well-studied. These noninflammasome-mediated AIDs relate to, for example, disturbance in the TNF or IFN signaling pathways or aberrations in genes affecting the IL-1RA. The spectrum of clinical signs and symptoms of these conditions is vast. Thus, recognizing early cutaneous signs constitutes an important step in differential diagnoses for dermatologists and other physicians. This review provides an overview of the pathogenesis, clinical presentation, and available treatment options highlighting dermatologic aspects of noninflammasome-mediated AIDs.

Macrophage Activation Syndrome (MAS): A Case Report and Narrative Review

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening syndrome of excessive inflammation and tissue destruction secondary to abnormal immune activation. The term macrophage activation syndrome (MAS) is used when HLH develops in the setting of systemic juvenile idiopathic arthritis (SJIA; formerly known as Still's disease), adult-onset Still's disease, or any other rheumatologic disorder. We present a case of a 21-year-old female with a known history of SJIA who presented to the hospital with fever, chills, myalgia, nausea, vomiting, and hypotension. Initial evaluation at the time of presentation suggested sepsis likely due to acute pyelonephritis, and the patient was started on antibiotics and intravenous fluid hydration. However, further workup suggested that her symptoms were non-infectious and were likely due to MAS, a rare complication of SJIA. We promptly diagnosed her, and she received a course of steroids and made an uneventful recovery.

The Expanding Spectrum of Autoinflammatory Diseases

Autoinflammatory diseases are systemic disorders caused by genetic or acquired abnormalities in certain signaling pathways of the innate immune system. Dysregulated activation of the inflammasome, i.e. molecular platforms responsible for the activation of caspase-1 and production of interleukin-1β, causes autoinflammation. Familial Mediterranean fever (FMF), the most common genetic autoinflammatory disease, is characterized by a periodic fever and serositis. The complex and heterogeneous genetic background of Japanese FMF patients, accompanied by potential overlap with other rheumatic diseases, suggests crosstalk between genetic and environmental factors. Recently, FMF has been recognized as being part of a spectrum of autoinflammatory syndromes named pyrin-associated autoinflammatory diseases. The discovery of a new monogenic autoinflammatory disease, A20 haploinsufficiency, may provide novel insights into early-onset Behçet's-like diseases. In contrast, adult-onset Still's disease and Schnitzler's syndrome are acquired autoinflammatory diseases without a monogenic abnormality. Although the concept of autoinflammatory diseases originally applied to monogenic hereditary recurrent fevers, it has been expanded to include non-genetic complex autoinflammatory diseases. Information concerning monogenic autoinflammatory diseases may prove useful for elucidating the molecular mechanisms underlying non-genetic autoinflammatory diseases.

Genetic and pharmacological targeting of GSDMD ameliorates systemic inflammation in macrophage activation syndrome

Macrophage activation syndrome (MAS), a potentially life-threatening complication of autoimmune/autoinflammatory diseases, is characterized by the excessive expansion and activation of macrophages and cytotoxic T lymphocytes in multiple organs. Most commonly, MAS occurs in patients with systemic juvenile idiopathic arthritis and in its adult equivalent, adult-onset Still's disease (AOSD). Gasdermin D (GSDMD) is a critical pore-forming effector protein that mediates pro-inflammatory cytokine secretion via releasing its N terminal fragments to form transmembrane pores. GSDMD has been implicated in various inflammatory diseases, however, its role in MAS remains elusive. Here, we unveiled that the serum levels of GSDMD-N were elevated in patients with AOSD compared to heathy controls. In addition, the emergence of MAS features in AOSD patients resulted in further elevation. The serum levels of GSDMD were positively correlated with ferritin and interleukin-18 (IL-18). Repeated toll-like receptor 9 stimulation with unmethylated cytosine-phosphate-guanine (CpG) induced MAS symptoms in wild-type mice, including body weight loss, pancytopenia and hepatosplenomegaly. Genetic deletion and pharmacological inhibition of GSDMD ameliorated MAS symptoms in mice with the concomitant reduction of splenic and hepatic macrophage infiltration and IL-18 production. Consistent with these in vivo results, bone marrow-derived macrophages obtained from GSDMD-/- mice or treated with GSDMD inhibitor disulfiram exhibited attenuated IL-18 expression after CpG stimulation. Collectively, our findings identified GSDMD as a novel marker for MAS complication and a promising target for MAS treatment.

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.

Short-term, low-dose etoposide in refractory adult-onset Still's disease-associated macrophage activation syndrome

INTRODUCTION

In this study, we modified the classical regimen of the hemophagocytic lymphohistiocytosis-04 protocol and evaluated the efficacy and safety of short-term, low-dose etoposide in patients with refractory macrophage activation syndrome (MAS) associated with adult-onset Still's disease (AOSD).

METHODS

A total of 17 patients with refractory AOSD-associated MAS were enrolled and received short-term, low-dose etoposide (100 mg twice a week for four times). Another 11 patients, who were not treated with etoposide, were included as historical controls. Patient information, such as clinical manifestations, laboratory results, treatments, and short-term prognosis, were recorded and analyzed.

RESULTS

In this case series, 88.24% of the patients with MAS who were treated with short-term, low-dose etoposide had a favorable response in 3 weeks, which was significantly higher (p = 0.017) than that in the patients with MAS who were treated without etoposide (45.45%). The 90-day survival rate after the onset of MAS was significantly higher (p = 0.0029) among the patients in the short-term etoposide group (16/17, 94.12%) than in the control group (5/11, 45.45%).

CONCLUSION

The regimen of short-term (2 weeks), low-dose etoposide was highly effective in the treatment for patients with refractory AOSD-associated MAS with an acceptable safety profile. Key Points • There is no high level evidence to guide the management of refractory MAS-associated AOSD patients. • This study was the first to propose and confirm the efficacy and safety of short-term, low-dose etoposide in the treatment of refractory MAS-associated AOSD patients.

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.

A Case of Macrophage Activation Syndrome During the Treatment of Adult-onset Still's Disease With Tocilizumab

Macrophage activation syndrome (MAS) is a fatal complication of adult-onset Still's disease (AOSD). Although anti-cytokine agents have been recommended for refractory AOSD or complicated with MAS, MAS cases have been rarely reported during anti-cytokine treatment. Herein, we describe the first AOSD case complicated with MAS during the treatment with tocilizumab in Korea. Two years after tocilizumab maintenance therapy, high fever and hypertransaminasemia recurred. MAS was diagnosed based on hyperferritinemia, elevated soluble IL-2 receptor levels, and the presence of hemophagocytic histiocytes in the bone marrow. However, she had normal white blood cell counts and acute phase reactant levels. High-dose glucocorticoid and anakinra therapies were not effective, but her disease improved with etoposide. This case shows that tocilizumab may not prevent MAS development and can modify clinical features making it challenging to diagnose. Cytotoxic therapy such as etoposide may be required in MAS cases that develop during anti-cytokine therapy.

Progress in Biological Therapies for Adult-Onset Still’s Disease

Adult-onset Still’s disease (AOSD) is a rare multifactorial autoinflammatory disorder of unknown etiology, characterized by an excessive release of cytokines triggered by dysregulated inflammation and articular and systemic manifestations. The clinical spectrum of AOSD ranges from self-limiting forms with mild symptoms to life-threatening cases and presents clinical and biological similarities with the juvenile form (sJIA). Nowadays, the advances in biologic agents no longer limit the treatment to NSAIDs, glucocorticoids, or conventional synthetic DMARDs. The blockade of IL-1 and IL-6 is effective in the treatment of systemic and articular inflammation of AOSD patients; however, novel compounds with different properties and targets are now available and others are being studied. In this review, starting from the pathogenesis of AOSD, we summarized the current and emerging biological therapies, possible effective agents for achieving AOSD control and remission.

The Expanding Spectrum of Autoinflammatory Diseases

Autoinflammatory diseases are systemic disorders caused by genetic or acquired abnormalities in certain signaling pathways of the innate immune system. Dysregulated activation of the inflammasome, i.e. molecular platforms responsible for the activation of caspase-1 and production of interleukin-1β, causes autoinflammation. Familial Mediterranean fever (FMF), the most common genetic autoinflammatory disease, is characterized by a periodic fever and serositis. The complex and heterogeneous genetic background of Japanese FMF patients, accompanied by potential overlap with other rheumatic diseases, suggests crosstalk between genetic and environmental factors. Recently, FMF has been recognized as being part of a spectrum of autoinflammatory syndromes named pyrin-associated autoinflammatory diseases. The discovery of a new monogenic autoinflammatory disease, A20 haploinsufficiency, may provide novel insights into early-onset Behçet's-like diseases. In contrast, adult-onset Still's disease and Schnitzler's syndrome are acquired autoinflammatory diseases without a monogenic abnormality. Although the concept of autoinflammatory diseases originally applied to monogenic hereditary recurrent fevers, it has been expanded to include non-genetic complex autoinflammatory diseases. Information concerning monogenic autoinflammatory diseases may prove useful for elucidating the molecular mechanisms underlying non-genetic autoinflammatory diseases.

Latent class analysis of 216 patients with adult-onset Still's disease

BACKGROUND

Adult-onset Still's disease (AOSD) is a rare systemic autoinflammatory disease which encompasses patients with heterogenous presentation and a wide range of clinical courses. In this study, we aimed to identify potential subgroups of AOSD and reveal risk factors for relapse.

METHODS

We included a total of 216 AOSD patients who received treatment in nine hospitals between 2000 and 2019. All patients fulfilled the Yamaguchi classification criteria. We retrospectively collected information about baseline characteristics, laboratory tests, treatment, relapse, and death. We performed latent class analysis and time-to-event analysis for relapse using the Cox proportional hazard model.

RESULTS

The median age at disease onset was 51.6 years. The median follow-up period was 36.8 months. At disease onset, 22.3% of the patients had macrophage activation syndrome. The median white blood cell count was 12,600/μL, and the median serum ferritin level was 7230 ng/mL. Systemic corticosteroids were administered in all but three patients (98.6%) and the median initial dosage of prednisolone was 40mg/day. Ninety-six patients (44.4%) were treated with concomitant immunosuppressants, and 22 (10.2%) were treated with biologics. Latent class analysis revealed that AOSD patients were divided into two subgroups: the typical group (Class 1: 71.8%) and the elderly-onset group (Class 2: 28.2%). During the follow-up period, 13 of 216 patients (6.0%) died (12 infections and one senility), and 76 of 216 patients (35.1%) experienced relapses. Overall and relapse-free survival rates at 5 years were 94.9% and 57.3%, respectively, and those rates were not significantly different between Class 1 and 2 (p=0.30 and p=0.19). Time-to-event analysis suggested higher neutrophil count, lower hemoglobin, and age ≥65 years at disease onset as risk factors for death and age ≥65 years at disease onset as a risk factor for relapse.

CONCLUSIONS

AOSD patients were divided into two subgroups: the typical group and the elderly-onset group. Although the survival of patients with AOSD was generally good, the patients often experienced relapses. Age ≥65 years at disease onset was the risk factor for relapse.

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

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

Risk of macrophage activation syndrome in patients with adult-onset Still's disease with skin involvement: A retrospective cohort study

BACKGROUND

Small case series and case reports indicated that atypical persistent pruritic eruptions (PPEs), another type of skin lesions seen in adult-onset Still's disease (AOSD), imply a worse prognosis than typical evanescent rashes.

OBJECTIVE

To investigate clinical characteristics and macrophage activation syndrome (MAS) occurrence in AOSD with PPEs.

METHODS

A retrospective cohort study analyzed 150 patients with AOSD with rashes at the First Affiliated Hospital of Zhejiang University from January 2013 to December 2019.

RESULTS

Patients with AOSD with PPEs had higher lactate dehydrogenase (492.00 U/L vs 382.00 U/L; P < .001) and ferritin (6944.10 ng/ml vs 4286.60 ng/ml; P = .033), and lower fibrinogen (5.05 g/L vs 5.77 g/L; P = .014) than those with evanescent rashes. Patients with AOSD with PPEs had a higher incidence (17.4% vs 3.1%, P = .006) and cumulative event rate for MAS (P = .008) and tended to receive high-dose glucocorticoid (36% vs 20.3%; P = .036). Multivariate analysis indicated that PPEs (hazard ratio [HR], 5.519; 95% confidence interval [CI], 1.138-26.767; P = .034), aspartate aminotransferase of greater than 120 U/L (HR, 8.084; 95% CI, 1.728-37.826; P = .008), and splenomegaly (HR, 21.152; 95% CI, 2.263-197.711; P = .007) were independent risk factors for MAS.

LIMITATIONS

Single-center, retrospective nature, small sample size.

CONCLUSION

PPEs indicated increased severity and MAS occurrence versus evanescent rashes. PPEs, aspartate aminotransferase of greater than 120 U/L, and splenomegaly were risk factors for MAS in AOSD with skin involvement.

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.

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.

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.

Total metabolic lesion volume of lymph nodes measured by 18F-FDG PET/CT: a new predictor of macrophage activation syndrome in adult-onset Still's disease

Background

To investigate the potential utility of quantitative parameters obtained by ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in the assessment of disease severity and the occurrence of macrophage activation syndrome (MAS) in adult-onset Still’s disease (AOSD).

Methods

Fifty-seven patients with AOSD who underwent pre-treatment ¹⁸F-FDG PET/CT were recruited in this study and compared with 60 age- and sex-matched healthy controls. Clinical features and laboratory data were recorded. The systemic score was assessed to determine the disease severity. The maximal standardized uptake value (SUV_max), metabolic lesion volume (MLV), and total lesion glycolysis (TLG) were used to evaluate the involved organs and tissues that abnormally accumulated ¹⁸F-FDG. Multivariate analysis was performed to identify the PET/CT-derived risk factors contributing to the AOSD-related MAS, and their diagnostic efficiency was evaluated.

Results

High ¹⁸F-FDG accumulation was observed in the bone marrow (SUV_max median, 5.10), spleen (SUV_max median, 3.70), and lymph nodes (LNs, SUV_max median, 5.55). The SUV_max of the bone marrow (rho = 0.376, p = 0.004), SUV_max of the spleen (rho = 0.450, p < 0.001), TLG_total of LNs (rho = 0.386, p = 0.017), and MLV_total of LNs (rho = 0.391, p = 0.015) were correlated with the systemic score. The SUV_max of the spleen (p = 0.017), TLG_total of LNs (p = 0.045), and MLV_total of LNs (p = 0.012) were higher in patients with MAS than in those without MAS. A MLV_total of LNs > 62.2 (OR 27.375, p = 0.042) was an independent predictive factor for MAS with a sensitivity of 80.0% and a specificity of 93.9%.

Conclusions

The glucose metabolic level of the spleen could be an effective and easy-to-use imaging indicator of disease severity, and MLV_total of LNs > 62.2 was a strong predictor of MAS occurrence in patients with AOSD.

Understanding of cytokines and targeted therapy in macrophage activation syndrome

Macrophage activation syndrome (MAS) is a potentially life-threatening complication of systemic autoinflammatory/autoimmune diseases, generally systemic juvenile idiopathic arthritis and adult-onset Still's disease. It is characterized by an excessive proliferation of macrophages and T lymphocytes. Recent research revealed that cytokine storm with elevated pro-inflammatory cytokines, including IFN-γ, IL-18, and IL-6, may be central to the pathogenesis of MAS. Though the mainstream of MAS treatment remains corticosteroids and cyclosporine, targeted therapies with anti-cytokine biologics are reported to be promising for controlling systemic inflammation in MAS.

Acute liver injury in a patient with adult-onset Still's disease-the challenge of differential diagnosis

In addition to the cardinal symptoms of fever, rash and arthralgia, liver involvement in patients with adult-onset Still's disease (AOSD) has been described. However, acute liver injury in AOSD patients can have various other causes: it can be a result of an AOSD-induced macrophage activation syndrome or be associated to the drugs given for the underlying diseases and symptoms. Differential diagnosis can therefore be challenging. We here present a case of a 32-year-old male with acute liver injury following the initial diagnosis of AOSD to discuss the possible underlying reasons.

Overlap between hemophagocytic lymphohistiocytosis and drug reaction and eosinophilia with systemic symptoms: a review

Drug reaction and eosinophilia with systemic symptoms (DRESS), also known as drug-induced hypersensitivity syndrome (DIHS), shares features with hemophagocytic lymphohistiocytosis (HLH), most notably fever, rash, and internal organ involvement. However, there is increasing recognition of drug-induced (secondary) HLH and biopsy-proven hemophagocytosis in DRESS, suggesting that HLH and DRESS not only overlap but also may be diseases on the same spectrum of immune dysfunction. To characterize existing literature on HLH/DRESS overlap, we queried the PubMed/MEDLINE database for 23 cases of HLH-DRESS codiagnosis. Average time-to-onset of rash after exposure to inciting drug was 2.7 weeks. Fourteen cases (61%) clinically worsened despite initial therapy, prompting a workup with diagnosis of HLH on average 2.3 weeks after diagnosing DRESS. Nine cases met HLH diagnostic criteria and had a RegiSCAR score ≥4. Nine cases met one set of criteria with a presentation suggestive of the other. Five cases met neither criteria. A patient presenting with fever, generalized rash, bicytopenia, and internal organ involvement after drug exposure was most predictive of meeting diagnostic criteria for both HLH and DRESS. Treatment was highly variable, although most initiated systemic corticosteroids with/without IVIG, plasmapheresis, or etoposide. Patients with poor outcomes in this review were treated using steroid monotherapy and had viral reactivation. Dermatologists should consider the possibility of HLH in any patient presenting with fever, rash, internal organ involvement, and cytopenia. Additional studies will be necessary to further characterize HLH and DRESS overlap and determine optimal management.

COVID-19: An Archetype Innate Immunity Reaction and Modes of Treatment

The magnitude of the SARS-CoV-2 pandemic found health systems unprepared, not allowing for prompt evaluation, collaboration among specialities and treatment of severely ill patients admitted to intensive care units, with many of them having an unfortunate outcome. Current data demonstrate an acute immune dysregulation in severe forms of the disease. The above is concluded by clinical evolution and laboratory findings, indicating a severe inflammatory response of the innate immune system, initiating predominately with the involvement of the respiratory tract epithelial cells, occasionally progressing to thrombotic diathesis and related complications. Besides the clinical manifestations, the immune response expresses an extremely high acute phase reactants repertoire including hyperferritinemia, hyper-fibrinogenaemia, and a storm of cytokines that require an alternative view and collaboration with rheumatologists. Thrombotic diathesis in some cases may not attribute only to a possible disseminated intravascular coagulation, but also to an additional activation of adaptive immunity and the development of the antiphospholipid syndrome. Unifying speciality evaluation and treatment may improve patient outcomes by recognizing early the evolving syndromes, treating properly, in a stratifying manner, with medications that alleviate the inflammatory reaction. Corticosteroids, colchicine, hydroxychloroquine/chloroquine, and possibly potent immunosuppressants are in the armamentarium. Additionally, biologics that interrupt the innate immune dysfunction, such as IL-1, IL-6 and selective JAK inhibitors, are also used. Convalescent plasma therapy and human immunoglobulin may be restricted for those whom the proposed treatments are found inadequate. The above combined with antiretroviral medications may improve the outcome until the development of safe and effective vaccination.

Targeting the Immune System for Pulmonary Inflammation and Cardiovascular Complications in COVID-19 Patients

In December 2019, following a cluster of pneumonia cases in China caused by a novel coronavirus (CoV), named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the infection disseminated worldwide and, on March 11th, 2020, the World Health Organization officially declared the pandemic of the relevant disease named coronavirus disease 2019 (COVID-19). In Europe, Italy was the first country facing a true health policy emergency, and, as at 6.00 p.m. on May 2nd, 2020, there have been more than 209,300 confirmed cases of COVID-19. Due to the increasing number of patients experiencing a severe outcome, global scientific efforts are ongoing to find the most appropriate treatment. The usefulness of specific anti-rheumatic drugs came out as a promising treatment option together with antiviral drugs, anticoagulants, and symptomatic and respiratory support. For this reason, we feel a duty to share our experience and our knowledge on the use of these drugs in the immune-rheumatologic field, providing in this review the rationale for their use in the COVID-19 pandemic.