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

Still's Disease Onset in Older Adults: Clinical Features, Diagnosis, and Management

Still's disease (SD) is a rare systemic inflammatory disease that is characterized by high fever, polyarthritis, and an evanescent rash as its main symptoms but that may also be complicated by pleuritis and macrophage activation syndrome (MAS). There has been a recent increase in studies on older-onset SD, which presents with less-typical clinical features, such as sore throat, skin lesions, and splenomegaly, but more complications including pleuritis and disseminated intravascular coagulation. Several reports have shown higher levels of inflammatory markers, including serum ferritin, and poorer outcomes in terms of survival and drug-free remission in older patients. In addition, caution is needed when diagnosing SD in older patients because of the increased incidence of differential diagnoses such as infectious diseases, malignancies, and inflammatory diseases. Prognosis is poor in older patients, and treatment-associated infections and severe complications such as MAS are the main cause of mortality. The use of biologics and treatment response may not differ greatly between older and younger patients. Although the data are limited, anti-IL-1 and anti-IL-6 agents may control SD in these patients with careful use and adequate infection prevention. Recent studies that classified adult-onset SD by cluster analysis or latent class analysis showed that older patients form a unique cluster of SD, indicating the need for clinicians to pay more attention to the diagnosis and management of SD in older patients.

Recent advances and evolving concepts in Still's disease

Still's disease is a rare inflammatory syndrome that encompasses systemic juvenile idiopathic arthritis and adult-onset Still's disease, both of which can exhibit life-threatening complications, including macrophage activation syndrome (MAS), a secondary form of haemophagocytic lymphohistiocytosis. Genetic insights into Still's disease involve both HLA and non-HLA susceptibility genes, suggesting the involvement of adaptive immune cell-mediated immunity. At the same time, phenotypic evidence indicates the involvement of autoinflammatory processes. Evidence also implicates the type I interferon signature, mechanistic target of rapamycin complex 1 signalling and ferritin in the pathogenesis of Still's disease and MAS. Pathological entities associated with Still's disease include lung disease that could be associated with biologic DMARDs and with the occurrence of MAS. Historically, monophasic, recurrent and persistent Still's disease courses were recognized. Newer proposals of alternative Still's disease clusters could enable better dissection of clinical heterogeneity on the basis of immune cell profiles that could represent diverse endotypes or phases of disease activity. Therapeutically, data on IL-1 and IL-6 antagonism and Janus kinase inhibition suggest the importance of early administration in Still's disease. Furthermore, there is evidence that patients who develop MAS can be treated with IFNγ antagonism. Despite these developments, unmet needs remain that can form the basis for the design of future studies leading to improvement of disease management.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Still's disease continuum from childhood to elderly: data from the international AIDA Network Still's disease registry

OBJECTIVE

Still's disease is more frequently observed in the paediatric context, but a delayed onset is not exceptional both in the adulthood and in the elderly. However, whether paediatric-onset, adult-onset and elderly-onset Still's disease represent expressions of the same disease continuum or different clinical entities is still a matter of controversy. The aim of this study is to search for any differences in demographic, clinical features and response to treatment between pediatric-onset, adult-onset and elderly-onset Still's disease.

METHODS

Subjects included in this study were drawn from the International AutoInflammatory Disease Alliance Network registry for patients with Still's disease.

RESULTS

A total of 411 patients suffering from Still's disease were enrolled; the disease occurred in the childhood in 65 (15.8%) patients, in the adult 314 (76.4%) patients and in the elderly in 32 (7.8%) patients. No statistically significant differences at post-hoc analysis were observed in demographic features of the disease between pediatric-onset, adult-onset and elderly-onset Still's disease. The salmon-coloured skin rash (p=0.004), arthritis (p=0.009) and abdominal pain (p=0.007) resulted significantly more frequent among paediatric patients than in adult cases, while pleuritis (p=0.015) and arthralgia (p<0.0001) were significantly more frequent among elderly-onset patients compared with paediatric-onset subjects. Regarding laboratory data, thrombocytosis was significantly more frequent among paediatric patients onset compared with adult-onset subjects (p<0.0001), while thrombocytopenia was more frequent among elderly-onset patients although statistical significance was only bordered. No substantial differences were observed in the response to treatments.

CONCLUSIONS

Despite some minor difference between groups, overall, demographic, clinical, laboratory and treatments aspects of Still's disease were similarly observed in patients at all ages. This supports that pediatric-onset, adult-onset and elderly-onset Still's disease is the same clinical condition arising in different ages.

Differences and similarities in cytokine profiles of macrophage activation syndrome in systemic lupus erythematosus and adult-onset Still's disease

To clarify the differences and similarities in the cytokine profiles of macrophage activating syndrome (MAS) between systemic lupus erythematosus (SLE) and adult-onset Still's disease (AOSD). The study participants included 9 patients with MAS-SLE, 22 with non-MAS-SLE, 9 with MAS-AOSD, and 13 with non-MAS-AOSD. Serum cytokine levels were measured using a multiplex bead assay. Cytokine levels were compared between patients with SLE and AOSD with/without MAS. Moreover, cytokine patterns were examined using principal component analysis (PCA) and cluster analysis. IL-6, IL-8, IL-18, and TNF-α levels were elevated in patients with SLE and AOSD. IFN-α levels were elevated in SLE, whereas IL-1β and IL-18 levels were elevated in AOSD. In SLE, IFN-α and IL-10 levels were higher in MAS than in non-MAS and controls. PCA revealed distinctive cytokine patterns in SLE and AOSD, SLE with IFN-α and IP-10, AOSD with IL-1β, IL-6, and IL-18, and enhanced cytokine production in MAS. PCA and cluster analysis showed no differences in cytokine patterns between the MAS and non-MAS groups. However, serum ferritin levels were correlated with IFN-α levels in SLE. Cytokine profiles differed between SLE and AOSD but not between MAS and non-MAS. MAS is induced by the enhancement of underlying cytokine abnormalities rather than by MAS-specific cytokine profiles. Type I IFN may be involved in MAS development in patients with SLE.

Derivation and validation of four patient clusters in Still's disease, results from GIRRCS AOSD-study group and AIDA Network Still Disease Registry

BACKGROUND

Different patient clusters were preliminarily suggested to dissect the clinical heterogeneity in Still's disease. Thus, we aimed at deriving and validating disease clusters in a multicentre, observational, prospective study to stratify these patients.

METHODS

Patients included in GIRRCS AOSD-study group and AIDA Network Still Disease Registry were assessed if variables for cluster analysis were available (age, systemic score, erythrocyte sedimentation rate (ESR), C reactive protein (CRP) and ferritin). K-means algorithm with Euclidean metric and Elbow plot were used to derive an adequate number of clusters.

RESULTS

K-means clustering assessment provided four clusters based on means standardised according to z-scores on 349 patients. All clusters mainly presented fever, skin rash and joint involvement. Cluster 1 was composed by 115 patients distinguished by lower values of age and characterised by skin rash myalgia, sore throat and splenomegaly. Cluster 2 included 128 patients identified by lower levels of ESR, ferritin and systemic score; multiorgan manifestations were less frequently observed. Cluster 3 comprised 31 patients categorised by higher levels of CRP and ferritin, they were characterised by fever and joint involvement. Cluster 4 contained 75 patients derived by higher values of age and systemic score. Myalgia, sore throat, liver involvement and life-threatening complications, leading to a high mortality rate, were observed in these patients.

CONCLUSIONS

Four patient clusters in Still's disease may be recognised by a multidimensional characterisation ('Juvenile/Transitional', 'Uncomplicated', 'Hyperferritinemic' and 'Catastrophic'). Of interest, cluster 4 was burdened by an increased rate of life-threatening complications and mortality, suggesting a more severe patient group.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

Introduction

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

Methods

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

Results

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

Conclusion

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

Clinical characteristics and prognosis in systemic lupus erythematosus-associated pulmonary arterial hypertension based on consensus clustering and risk prediction model

BACKGROUND

Pulmonary arterial hypertension (PAH) is a severe complication of systemic lupus erythematosus (SLE). This study aims to explore the clinical characteristics and prognosis in SLE-PAH based on consensus clustering and risk prediction model.

METHODS

A total of 205 PAH (including 163 SLE-PAH and 42 idiopathic PAH) patients were enrolled retrospectively based on medical records at the First Affiliated Hospital of Zhengzhou University from July 2014 to June 2021. Unsupervised consensus clustering was used to identify SLE-PAH subtypes that best represent the data pattern. The Kaplan-Meier survival was analyzed in different subtypes. Besides, the least absolute shrinkage and selection operator combined with Cox proportional hazards regression model were performed to construct the SLE-PAH risk prediction model.

RESULTS

Clustering analysis defined two subtypes, cluster 1 (n = 134) and cluster 2 (n = 29). Compared with cluster 1, SLE-PAH patients in cluster 2 had less favorable levels of poor cardiac, kidney, and coagulation function markers, with higher SLE disease activity, less frequency of PAH medications, and lower survival rate within 2 years (86.2% vs. 92.8%) (P < 0.05). The risk prediction model was also constructed, including older age at diagnosis (≥ 38 years), anti-dsDNA antibody, neuropsychiatric lupus, and platelet distribution width (PDW).

CONCLUSIONS

Consensus clustering identified two distinct SLE-PAH subtypes which were associated with survival outcomes. Four prognostic factors for death were discovered to construct the SLE-PAH risk prediction model.

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).

Elevated White Blood Cell Count and Lactate Dehydrogenase Levels Are Important Markers for Diagnosing Relapse of Adult-onset Still's Disease under Tocilizumab Use

We encountered a case of refractory adult-onset Still's disease (AOSD) with two relapses. Prednisolone and methotrexate were begun as induction therapy, resulting in the patient's first relapse during tapering of prednisolone. After the introduction of tocilizumab, she achieved remission. However, she experienced a second relapse following prednisolone tapering. While lactate dehydrogenase (LDH) levels and white blood cell (WBC) counts increased in both relapses, interleukin-6 (IL-6) suppression resulted in stable C-reactive protein and ferritin levels in the second relapse. A comparison of the two relapses indicated that increases in both WBC counts and LDH levels can aid in the diagnosis of AOSD relapse.

Clinical features and serum cytokine profiles of elderly-onset adult-onset Still's disease

Recent studies have suggested that the clinical features of elderly-onset adult-onset Still's disease (AOSD) differ from those of young and middle-aged-onset patients, whereas the details remain unclear, and cytokine profiles of elderly-onset AOSD have not been reported. To clarify the clinical features and cytokine profiles of elderly-onset AOSD, we examined patients with AOSD who developed the disease between January 2006 and September 2021. We divided the patients into the young and middle-aged-onset group (aged < 65 years) and the elderly-onset group (aged ≥ 65 years) and compared the groups in terms of patient characteristics, clinical symptoms, laboratory findings including serum interleukin (IL)-6 and IL-18, treatment, and prognosis. A total of 48 patients were examined (10 in the elderly-onset group). In the elderly-onset group, atypical rash was significantly more frequent, typical rash and splenomegaly were significantly less frequent, white blood cell count and neutrophil ratio were significantly higher and serum IL-6 levels were significantly lower. Serum IL-6 showed a significantly negative correlation with age at onset. Treatment and relapse were comparable between the 2 groups, whereas infections were significantly more frequent in the elderly-onset group. The clinical features and cytokine profiles of elderly-onset AOSD might differ from those of young and middle-aged-onset AOSD.

The Spectrum of Still's Disease: A Comparative Analysis of Phenotypic Forms in a Cohort of 238 Patients

Still's disease (SD) is a heterogeneous autoinflammatory disorder for which several phenotypes have been described. We conducted a retrospective study to re-evaluate the dichotomous view of the disease, to compare the juvenile and adult forms, and to look for prognostic factors. We collected data from ten French centers, seeking patients with a diagnosis of adult-onset SD (AOSD) or systemic juvenile idiopathic arthritis (sJIA). We identified 238 patients, 152 (64%) of whom had AOSD while 86 (36%) had sJIA. The median age at SD onset was 26.6 years. In patients with identifiable patterns, the course of SD was systemic in 159 patients (74%), chronic in 55 (26%). Sore throat and myalgia were more frequent in patients with AOSD. Abnormal liver tests, serum ferritin and C-reactive protein levels were higher in AOSD group. Fever and skin rash were predictive of complete remission or recovery and high lactate dehydrogenase level was a poor prognosis factor. Symptoms such as splenomegaly, skin rash, high polymorphonuclear neutrophils count and macrophage activation syndrome were predictive of a systemic phenotype. Overall, there were no major differences between sJIA and AOSD. Our results are consistent with the "biphasic" model of an autoinflammatory disease that can progress to chronic arthritis if not treated early.

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

Objectives

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

Methods

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

Results

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

Conclusions

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

Adult-Onset Still’s Disease-like Syndrome following COVID-19 Vaccination: A Case Report and Review of the Literature

Adult-onset Still’s disease (AOSD)-like syndrome has rarely been reported as a complication of COVID-19 vaccination. This study reports a 31-year-old female patient who presented with fever, myalgia, arthralgia, pleuropericarditis, leukocytosis, and transaminitis following ChAdOx1 vaccination, and met Yamaguchi’s criteria. A PubMed literature search, performed up until March 2022, identified 10 such cases. A total of 11 cases, including the one in this report, developed AOSD-like syndrome after administration of the viral vector (ChAdOx1) vaccine (six patients) and mRNA vaccine (five patients: BNT162b2 in four and mRNA-1273 in one). There were four male and seven female patients, with their median (Q1, Q3) age and the onset of symptoms after vaccination being 36 years (29, 45) and 10 days (6, 13), respectively. Fever (100%), arthralgia/arthritis (90.9%), skin rashes (81.8%), and sore throat (81.8%) were the main clinical findings. Pericarditis (45.5%), myocarditis/cardiac dysfunction (36.4%), pleuritis (54.6%), and pulmonary infiltrations (36.4%) were also common. One patient developed macrophage activation syndrome. One patient responded well to non-steroidal anti-inflammatory drugs, and the other six showed a good response to high-dose corticosteroids alone. Of the remaining four patients, who showed partial responses to high dose corticosteroids, showed good responses to biological agents. AOSD-like syndrome following COVID-19 vaccination shared many similar clinical features and treatment outcomes to those of idiopathic AOSD (but with a higher prevalence of cardiopulmonary involvement in the former). Physicians should be aware of this extremely rare complication to achieve early diagnosis and provide proper management.

Expanding the spectrum of the hyperferritinemic syndrome, from pathogenic mechanisms to clinical observations, and therapeutic implications

From the introduction of hyperferritinemic syndrome concept, a growing body of evidence has suggested the role of ferritin as a pathogenic mediator and a relevant clinical feature in the management of patients with inflammatory diseases. From a pathogenic point of view, ferritin may directly stimulate the aberrant immune response by triggering the production of pro-inflammatory mediators in inducing a vicious pathogenic loop and contributing to the occurrence of cytokine storm syndrome. The latter has been recently defined as a clinical picture characterised by elevated circulating cytokine levels, acute systemic inflammatory symptoms, and secondary organ dysfunction beyond that which could be attributed to a normal response to a pathogen It is noteworthy that the occurrence of hyperferritinemia may be correlated with the development of the cytokine storm syndrome in the context of an inflammatory disease. In addition to adult onset Still's disease, macrophage activation syndrome, catastrophic anti-phospholipids syndrome, and septic shock, recent evidence has suggested this association between ferritin and life-threatening evolution in patients with systemic lupus erythematosus, with anti-MDA5 antibodies in the context of poly-dermatomyositis, with severe COVID-19, and with multisystem inflammatory syndrome. The possible underlying common inflammatory mechanisms, associated with hyperferritinemia, may led to the similar clinical picture observed in these patients. Furthermore, similar therapeutic strategies could be suggested inhibiting pro-inflammatory cytokines and improving long-term outcomes in these disorders. Thus, it could be possible to expand the spectrum of the hyperferritinemic syndrome to those diseases burdened by a dreadful clinical picture correlated with hyperferritinemia and the occurrence of the cytokine storm syndrome. In addition, the assessment of ferritin may provide useful information to the physicians in clinical practice to manage these patients. Therefore, ferritin may be considered a relevant clinical feature to be used as biomarker in dissecting the unmet needs in the management of these disorders. Novel evidence may thus support an expansion of the spectrum of the hyperferritinemic syndrome to these diseases burdened by a life-threatening clinical picture correlated with hyperferritinemia and the occurrence of the cytokine storm syndrome.

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

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