Impact of smoking habit on adult-onset Still's disease prognosis, findings from a multicentre observational study

Cigarette smoking and risk of adult-onset Still disease: a propensity score matching analysis

BACKGROUND

Environmental factors play an important role in the pathogenesis of rheumatic diseases. Smoking is thought to be a risk factor for autoimmune rheumatic diseases.

AIMS

The purpose of the present study was to assess the association between smoking and adult-onset Still disease (AOSD) and the effect of smoking on outcomes of this disease.

METHODS

In this case-control study, patients with AOSD who met the Yamaguchi criteria, were older than 16 years at the disease onset and were in follow-up for at least 12 months were consecutively enrolled in the study. The outcome of AOSD was assessed by acquiring remission on treatment, remission off treatment, time to remission and rate of flare. The smoking status of participants was defined by direct or phone interviews. Individuals who had smoked daily for at least 6 months were defined as a smoker. We performed propensity score matching analyses by using four parameters, including age, sex, educational status and marital status.

RESULTS

Propensity score matching resulted in 72 patients with AOSD and 216 matched controls. The number of ever smokers in the AOSD and control groups were 11 (15.3%) and 25 (11.6%) respectively. There was no significant increase in the risk of AOSD in multivariate analysis after adjustment for age, sex, marital status and educational level. There were no significant differences in the outcomes of AOSD between ever and never smokers.

CONCLUSIONS

Smoking probably is not a risk factor for AOSD and did not affect the response to treatment.

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.

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.

[Update on Adult-Onset Still's Disease: Diagnosis, Therapy and Guideline]

Adult-onset Still's disease (ASOD) is an autoinflammatory disease of unknown etiology which is pathogenetically characterized by an involvement of the innate immune response with activation of neutrophils and an increased secretion of IL-1, IL-6, IL-18, type 1 interferons. Still's disease may occur at any age with distinct variability in signs and symptoms. Recently, the German Society of Rheumatology (DGRh) has issued an AOSD guideline which recommends diagnosing AOSD based on a characteristic combination of symptoms including intermittent fever, rash, arthralgia, and arthritis after exclusion of infections, neoplasms and other rheumatological conditions. Classification criteria according to Yamaguchi may support the clinical diagnosis. Therapy is recommended to include glucocorticosteroids and methotrexate or ciclosporin, at higher activity levels IL1-receptor antagonist anakinra, IL-1β antibody canakinumab, or IL6-receptor antibody tocilizumab. At a high disease activity, anakinra or canakinumab may be employed primarily. Local drug licensing policies may have to be considered, as these substances are not universally approved in these scenarios. Important complications to consider consist in perimyocarditis, a multi-faceted pulmonary involvement, and macrophage activation syndrome (MAS). MAS features multi-organ involvement and cytopenias. Besides supportive measures often requiring intensive care, high dose glucocorticosteroids as well as above named biologics, and if necessary, also etoposide based therapeutic regimen are used.

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

INTRODUCTION

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

AREA COVERED

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

EXPERT OPINION

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