Adult-onset Still's disease

Racial/Ethnic variations in morbidity and mortality in Adult Onset Still's Disease: An analysis of national dataset

OBJECTIVES

Adult Onset Still's Disease (AOSD) is a rare autoinflammatory disorder. There is relatively little known about the impact of social determinants of health on its outcomes. Our goal is to describe the racial/ethnic variations, morbidity and mortality of AOSD hospitalized patients in the US.

MATERIALS AND METHODS

Adult US hospitalized patients between 2009-13 from a nationwide inpatient sample (NIS) database with AOSD were identified using ICD-9 code 714.2. NIS is the largest all-payer US inpatient database with approximately 8 million hospitalizations yearly. Patients with other autoimmune diseases were excluded. We used descriptive statistics to summarize patient and hospital characteristics. We performed survey-weighted logistic regression models adjusting for confounders to study our primary outcome: in-hospital mortality.

RESULTS

Between 2009-13, 5,820 AOSD patients were hospitalized with a mean age of 53.6 (SE-0.61) years. 3817 (65.6%) were female, 56% white and 3% Asian. Macrophage Activating Syndrome (1.7%), Disseminated Intravascular Coagulation (DIC-1.1%) and Thrombotic Thrombocytopenic Purpura (0.4%), respectively, complicated the hospital course. There were 154 inpatient deaths in study period (mortality 2.6%). Mean age of patients who died in hospital was higher (62.4 years ± 3.1) and 13.9% were Asians. Patients of Asian origin had significantly higher odds of in-hospital death compared to whites (aOR = 6.39, 95% CI 1.77-23.1, p = 0.005). Mortality was significantly higher for patients whose hospital course was complicated by DIC (aOR = 29.69, 95% CI 5.5-160.41, p = 0.006).

CONCLUSIONS

In this national sample of patients hospitalized for AOSD, we found significant variations in In-hospital mortality.

Cytomegalovirus Infection May Trigger Adult-Onset Still's Disease Onset or Relapses

Previous studies have revealed that several micro-organisms, especially DNA viruses, have been associated with adult-onset Still's disease (AOSD). However, there are no studies on the relationship between the presence of viral infections in AOSD patients with disease occurrence and reactivation. In the present study, we aimed to investigate the presence of antibodies against virus, virus DNA load and nucleic acid sensors in AOSD patients. Anti-viral antibodies were measured by enzyme-linked immunosorbent assay (ELISA) in plasma samples from 100 AOSD patients and 70 healthy controls (HCs). The copy number of cytomegalovirus (CMV) DNA in 100 AOSD patients was detected by PCR. The expression levels of nucleic acid sensors interferon gamma-inducible protein 16 (IFI16) and absent in melanoma 2 (AIM2) in peripheral blood mononuclear cell (PBMC) and skin from AOSD patients and HCs were analyzed by PCR and immunohistochemistry. The levels of antibodies against CMV were significantly higher in AOSD patients compared to HCs. Moreover, the level of anti-CMV IgM antibody was significantly increased in patients with fever, sore throat, arthralgia and rash. CMV DNA was found in plasma of AOSD patients with disease new-onset and relapse. Furthermore, the copy number of CMV DNA significantly increased in patients with fever, sore throat, arthralgia and rash. And the significant associations of the CMV DNA level with the levels of leukocytes, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α) were observed. Moreover, we found an upregulation of cytoplasmic DNA-sensing receptor IFI16 and AIM2 in PBMC and skin from AOSD patients. In conclusion, our results showed that CMV infection may play a role in the initiation or amplification of inflammatory responses in AOSD.

Recommendations for the management of hemophagocytic lymphohistiocytosis in adults

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome induced by aberrantly activated macrophages and cytotoxic T cells. The primary (genetic) form, caused by mutations affecting lymphocyte cytotoxicity and immune regulation, is most common in children, whereas the secondary (acquired) form is most frequent in adults. Secondary HLH is commonly triggered by infections or malignancies but may also be induced by autoinflammatory/autoimmune disorders, in which case it is called macrophage activation syndrome (MAS; or MAS-HLH). Most information on the diagnosis and treatment of HLH comes from the pediatric literature. Although helpful in some adult cases, this raises several challenges. For example, the HLH-2004 diagnostic criteria developed for children are commonly applied but are not validated for adults. Another challenge in HLH diagnosis is that patients may present with a phenotype indistinguishable from sepsis or multiple organ dysfunction syndrome. Treatment algorithms targeting hyperinflammation are frequently based on pediatric protocols, such as HLH-94 and HLH-2004, which may result in overtreatment and unnecessary toxicity in adults. Therefore, dose reductions, individualized tailoring of treatment duration, and an age-dependent modified diagnostic approach are to be considered. Here, we present expert opinions derived from an interdisciplinary working group on adult HLH, sponsored by the Histiocyte Society, to facilitate knowledge transfer between physicians caring for pediatric and adult patients with HLH, with the aim to improve the outcome for adult patients affected by HLH.

An adult case of atypical familial Mediterranean fever (pyrin-associated autoinflammatory disease) similar to adult-onset Still's disease

We present a 55-year-old woman with periodic fever and symptoms similar to adult-onset Still's disease (AOSD). She had a heterogeneous mutation of the MEFV gene and colchicine was effective. Atypical familial Mediterranean fever (pyrin-associated autoinflammatory disease) should be considered in patients with periodic fever accompanied by symptoms similar to AOSD.

State of care for patients with systemic autoinflammatory diseases - Results of a tertiary care survey

BACKGROUND

Systemic autoinflammatory diseases (SAIDs) are rare debilitating disorders of which there is limited awareness and a significant delay in diagnosis. There is no uniform approach in the diagnosis and treatment of these disorders and the real life state of SAID patient care is poorly characterized. The aim of this study was to obtain data on the epidemiology, state of care and the perception of physicians who are involved in the care of SAID patients.

METHODS

We performed a questionnaire-based survey and contacted 134 university departments of dermatology, pediatrics, rheumatology and other SAID departments of tertiary care in German-speaking countries.

RESULTS

A total of 37 departments participated in the survey. The majority of departments managed both adult and pediatric patients with a variety of monogenic and polygenic/acquired SAIDs. For monogenic SAIDs such as cryopyrin-associated periodic syndromes (CAPS) and familial Mediterranean fever (FMF), the diagnostic and treatment strategies were similar among the departments. The diagnostic work-up included inflammatory markers and genetic testing, the first line treatment interleukin-1 (IL-1) blockers for CAPS and colchicine for FMF. For polygenic/acquired SAIDs, we observed a significant heterogeneity in diagnostic and therapeutic approaches. As a major unmet need, diagnostic delay was identified with a median time to diagnosis of 2 (range 1-5) years. The overall state of care for SAID patients was rated to be excellent or good by only 12% of departments, and to be poor or non-sufficient by 40% of departments.

CONCLUSION

This study demonstrates a high need to improve the state of care and to harmonize diagnostic and treatment strategies for SAID patients.

Characteristics of Circulating Natural Killer Cells and Their Interferon-γ Production in Active Adult-onset Still Disease

Objective.

To investigate the characteristics of circulating natural killer (NK) cells and their interferon (IFN)-γ–producing ability in adult-onset Still disease (AOSD).

Methods.

Peripheral blood mononuclear cells were obtained from 22 patients in the acute phase of AOSD (acute AOSD); 7 of the 22 patients after treatment (remission AOSD), and 11 healthy controls (HC). NK cells and their IFN-γ expression levels were analyzed by flow cytometry. Additionally, the cytokine receptors of interleukin (IL)-12, IL-15, and IL-18 on NK cells were also evaluated.

Results.

The frequency of NK cells was significantly lower in acute AOSD than in HC. NK cell counts significantly increased in remission AOSD. Expression of IL-12 and IL-15 receptors on NK cells was significantly increased in acute AOSD, whereas that of IL-18 receptor indicated no significant difference among 3 groups. IFN-γ expression in NK cells was significantly higher in acute AOSD than in HC, and significantly decreased in remission AOSD. The absolute number of NK cells and IFN-γ–expressing NK cells revealed an inverse correlation with serum ferritin levels in acute AOSD. In 2 distinct subsets of NK cells, CD56dim NK cells significantly exhibited higher IFN-γ expression than CD56bright NK cells in acute AOSD.

Conclusion.

In acute AOSD, NK cells displayed lower proportion, whereas they had higher ability for IFN-γ production than in HC; moreover, upregulation of IL-12 and IL-15 receptors on NK cells may promote IFN-γ production. In addition, disease activity may be implicated in regulating the number of NK cells and IFN-γ–expressing NK cells in AOSD.

Histopathological diagnosis of persistent pruritic eruptions associated with adult-onset Still's disease

AIMS

Persistent pruritic eruptions (PPEs), presenting with dyskeratotic keratinocytes histologically, are characteristic skin rash in patients with adult-onset Still's disease (AOSD). The lesions may be histologically similar to other entities that present with dyskeratosis. In the present study, we compared the histopathological features between PPEs and other entities presenting with dyskeratosis.

METHODS AND RESULTS

To investigate whether histopathological findings can be used to discriminate among PPEs and other entities presenting with dyskeratotic keratinocytes, cutaneous histopathological changes of PPEs associated with AOSD (n = 26) were compared with those of systemic lupus erythematosus (SLE) (n = 16), dermatomyositis (n = 19), and drug eruption (n = 16). Dyskeratosis was observed in the upper one-third of the epidermal layer in all 26 PPEs. The rate of dyskeratosis for PPEs was higher than that for SLE (18.8%) and dermatomyositis (15.8%). In drug eruptions, the dyskeratotic cells were distributed in all levels of the epidermis. Variable densities of neutrophils were found in the dermis in all PPEs.

CONCLUSIONS

Although this was a retrospective study conducted at a single centre, presentation of dyskeratotic keratinocytes in the upper one-third of the epidermal layer is a distinctive histopathological reactive pattern of PPEs. This pattern may be a useful histopathological marker for early diagnosis of AOSD.

Adult-onset Still's disease biological treatment strategy may depend on the phenotypic dichotomy

OBJECTIVES

Adult-onset Still's disease (AOSD) phenotype appears to be dichotomized in systemic or chronic articular forms. As biologicals and particularly interleukin (IL)-1 and IL-6 blockers play a more and more prominent role in the treatment, their place requires clarification. This study aimed to identify factors predictive of treatment response to anakinra or tocilizumab and investigate whether the choice of biotherapy and delays in the initiation of biotherapy influenced the likelihood of steroid discontinuation.

METHODS

A multicenter exploratory retrospective study included all patients diagnosed with AOSD and receiving biological treatments in three regional hospitals until 2018. Clinical and biological characteristics at diagnosis and treatment-related data were collected. The nonparametric Mann-Whitney test was used to perform univariate analysis for quantitative variables, and Fisher's exact test was used for qualitative variables.

RESULTS

Twenty-seven patients were included. All but one patient achieved remission with either anakinra or tocilizumab. Treatment responses depended on disease phenotype: the presence of arthritis and a chronic articular phenotype were associated with a substantial response to tocilizumab with p = 0.0009 (OR 36 [2.6-1703]) and p = 0.017 (OR 10 [1.22-92.6]), respectively, whereas the systemic form and the absence of arthritis were associated with a substantial response to anakinra with p = 0.0009 (OR 36 [2.6-1703]) and p = 0.017 (OR 10 [1.22-92.6]), respectively. Tocilizumab increased the likelihood of corticosteroid withdrawal (p = 0.029) regardless of delays in initiation or when it was initiated relative to other treatment in the overall therapeutic strategy.

CONCLUSION

This study highlights the therapeutic implications of the phenotypic dichotomy of AOSD and should help us better codify AOSD treatment.

Plasma microRNA Profiles as a Potential Biomarker in Differentiating Adult-Onset Still's Disease From Sepsis

Adult-onset Still's disease (AOSD) is a systemic inflammatory disease characterized by cytokine storm. However, a diagnostic test for AOSD in clinical use is yet to be validated. The aim of our study was to identify non-invasive biomarkers with high specificity and sensitivity to diagnosis of AOSD. MicroRNA (miRNA) profiles in PBMC from new-onset AOSD patients without any treatment and healthy controls (HCs) were analyzed by miRNA deep sequencing. Plasma samples from 100 AOSD patients and 60 HCs were used to validated the expression levels of miRNA by qRT-PCR. The correlations between expression levels of miRNAs and clinical manifestations were analyzed using advanced statistical models. We found that plasma samples from AOSD patients showed a distinct miRNA expression profile. Five miRNAs (miR-142-5p, miR-101-3p, miR-29a-3p, miR-29c-3p, and miR-141-3p) were significantly upregulated in plasma of AOSD patients compared with HCs both in training and validation sets. We discovered a panel including 3 miRNAs (miR-142-5p, miR-101-3p, and miR-29a-3p) that can predict the probability of AOSD with an area under the receiver operating characteristic (ROC) curve of 0.8250 in training and validation sets. Moreover, the expression levels of 5 miRNAs were significantly higher in active AOSD patients compared with those in inactive patients. In addition, elevated level of miR-101-3p was found in AOSD patients with fever, sore throat and arthralgia symptoms; the miR-101-3p was also positively correlated with the levels of IL-6 and TNF-α in serum. Furthermore, five miRNAs (miR-142-5p, miR-101-3p, miR-29c-3p, miR-29a-3p, and miR-141-3p) expressed in plasma were significantly higher in AOSD patients than in sepsis patients (P < 0.05). The AUC value of 4-miRNA panel (miR-142-5p, miR-101-3p, miR-29c-3p, and miR-141-3p) for AOSD diagnosis from sepsis was 0.8448, revealing the potentially diagnostic value to distinguish AOSD patients from sepsis patients. Our results have identified a specific plasma miRNA signature that may serve as a potential non-invasive biomarker for diagnosis of AOSD and monitoring disease activity.

Increased neutrophil extracellular traps activate NLRP3 and inflammatory macrophages in adult-onset Still's disease

Background

Adult-onset Still’s disease (AOSD) is a systemic inflammatory disease characterized by neutrophilia and NLRP3 inflammasome and macrophage activation. We investigated the role of neutrophil extracellular traps (NETs) in the pathogenesis of AOSD, and explored the effect of NETs on activating NLRP3 inflammasome and proinflammatory macrophages.

Methods

The sera of 73 AOSD patients and 40 healthy controls were used to detect the level of cell-free DNA and NET-DNA complexes. NET formation ex vivo was analyzed using immunofluorescence and flow plates. The activation of NLRP3 inflammasome in THP-1 cells and proinflammatory macrophages stimulated with DNA purified from NETs was measured using RT-PCR, ELISA, Western blotting and flow cytometry.

Results

The levels of cell-free DNA and NET-DNA complexes were significantly increased in the circulation of patients with AOSD compared with healthy controls, and freshly isolated neutrophils from patients with AOSD were predisposed to high levels of spontaneous NET release. Interestingly, enhanced NET release was abrogated with NADPH oxidase inhibitors and a mitochondrial scavenger. Furthermore, DNA purified from AOSD NETs activated NLRP3 inflammasomes. NET DNA from AOSD also exerted a potent capacity to accelerate the activation of CD68⁺CD86⁺ macrophages and increased the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. Finally, the copy number of mitochondrial DNA (mtDNA) in NETs and plasma was significantly increased in AOSD patients, suggesting that mtDNA may be involved in the activation of NLRP3 and inflammatory macrophages.

Conclusions

These findings implicate accelerated NET formation in AOSD pathogenesis through activation of NLRP3 and proinflammatory macrophages, and identify a novel link between neutrophils and macrophages by NET formation in AOSD.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1800-z) contains supplementary material, which is available to authorized users.

Generation and characterization of antagonistic anti-human interleukin (IL)-18 monoclonal antibodies with high affinity: Two types of monoclonal antibodies against full-length IL-18 and the neoepitope of inflammatory caspase-cleaved active IL-18

Interleukin-18 (IL-18) is a pro-inflammatory cytokine that evokes both innate and acquired immune responses. IL-18 is initially synthesized as an inactive precursor and the cleavage for processing into a mature, active molecule is mediated by pro-inflammatory caspases following the activation of inflammasomes. Two types of monoclonal antibodies were raised: anti-IL-18^63-68 antibodies which recognize full-length^1-193 and cleaved IL-18; and anti-IL-18 neoepitope antibodies which specifically recognize the new N-terminal ³⁷YFGKLESK⁴⁴ of IL-18 cleaved by pro-inflammatory caspase-1/4. These mAbs were suitable for Western blotting, capillary Western immunoassay (WES), immunofluorescence, immunoprecipitation, and function-blocking assays. WES analysis of these mAbs allowed visualization of the IL-18 bands and provided a molecular weight corresponding to the pro-inflammatory caspase-1/4 cleaved, active form IL-18^37-193, and not to the inactive precursor IL-18, in the serum of patients with adult-onset Still's disease (6/14, 42%) and hemophagocytic activation syndrome (2/6, 33%). These monoclonal antibodies will be very useful in IL-18 and inflammasome biology and for diagnostic and therapeutic strategies for inflammatory diseases.

Characteristic patterns of HLA presentation and T cell differentiation in adult-onset Still's disease

We examined the expression of human leukocyte antigen (HLA) and composition of differentiated T cells in the peripheral blood to understand the characteristics of the immune changes in patients with adult-onset Still’s disease (AOSD). This study enrolled patients with AOSD (n = 14), patients with rheumatoid arthritis (RA, n = 20), and healthy controls (HC, n = 20). The percentage of surface-stained cells with HLA-DP, DQ, and DR alleles and the composition of differentiated T cells in peripheral blood leukocytes (PBLs) were evaluated by flow cytometry. AOSD patients exhibited significantly higher percentages of lymphocytes presenting HLA-DP and HLA-DR, and lower percentages of cells presenting HLA-DQ, than RA patients or HC. The proportions of CD4+, CD4+CCR7+, CD4+CD62L–, and CD8+CD62L– cells from PBLs were decreased in AOSD patients relative to RA patients or HCs. By contrast, AOSD patients had higher proportions of CD8+naïve T cells in whole blood relative to RA patients or HC. The proportions of CD4+ effector memory T cells, CD8+ naïve T cells, and CD8+ effector memory T cells in whole blood cells and CD4+ effector memory T cell in lymphocytes were significantly associated with the systemic score. While the proportions of CD4+, CD8+, CCR7+, CD4+CCR7+, CD4+CD62L–, and CD8+CD62L– cells were significantly decreased in AOSD patients, and the proportion of CD8+naïve T cells was elevated in AOSD and correlated with the systemic score. Further studies of a large cohort of AOSD patients will be necessary to evaluate these markers in the pathogenesis of AOSD.

Pulmonary arterial hypertension in adult-onset Still's disease: A case series and systematic review of the literature

OBJECTIVE

To investigate the prevalence, clinical characteristics and prognosis of pulmonary arterial hypertension (PAH) in adult onset Still's disease (AOSD).

METHODS

We retrospectively reviewed all patients with AOSD diagnosed during a 33-year period in 2 referral tertiary care hospitals, selecting for analysis those who presented PAH confirmed as by right heart catheterization. A systematic review of the literature (PubMed 1990 to July 2018) was also performed, in order to determine the prognosis and the most appropriate treatment strategy for this complication.

RESULTS

The overall prevalence of PAH in our AOSD population was 4.8% (2/41). Including our 2 cases, 20 well-documented patients have been reported. PAH may complicate AOSD at any time during its course, and usually occurs in patients who have persistent and severe disease, with a considerable frequency (35%) of previous or concomitant severe clinical complications. In all cases, the etiology of pulmonary hypertension was a group 1 PAH based on the 2015 ESC/ERS guidelines. Most patients in this series had advanced WHO functional classes III-IV at the time of PAH diagnosis, reflecting an important diagnostic delay. Thirty-three percent of patients had a poor outcome despite the therapy, with a mortality rate that reached 22%. The therapeutic strategy that achieved the best results was the use of glucocorticoids, immunosuppression and PAH-specific vasodilator therapy.

CONCLUSION

HAP is an under-recognized complication of AOSD that should be kept in mind in the differential diagnosis of those patients who experience dyspnea on exertion or a decrease in exercise tolerance.

Serum amyloid A1 (SAA1) gene polymorphisms in Japanese patients with adult-onset Still's disease

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disorder in which inflammasome activation plays a pathophysiological role. In view of the inflammatory nature of AOSD, we investigated whether serum amyloid A (SAA) gene polymorphisms affect the susceptibility of patients with AOSD.Eighty-seven Japanese patients with AOSD and 200 healthy Japanese subjects were recruited in this study. The genotypes of the -13C/T SNP in the 5'-flanking region of the SAA1 gene (rs12218) and two SNPs within exon 3 of SAA1 (2995C/T and 3010C/T polymorphisms) were determined using polymerase chain reaction fragment length polymorphism (PCR-RFLP) assay in all subjects. In AOSD patients, exons 1, 2, 3, and 10 of the MEFV gene were also genotyped by direct sequencing.The frequency of the SAA1.3 allele was increased in AOSD patients compared with that in healthy subjects (43.1% versus 37.5%), but the difference was not significant. The -13T allele was more frequently observed in AOSD patients than in healthy subjects (50.6% versus 41.0%, P = .0336). AOSD patients with the -13T allele had been treated with immunosuppressants more frequently than those without this allele. MEFV mutations were detected in 49 patients with AOSD (49/87, 57.3%). AOSD patients with MEFV variants frequently exhibit macrophage activation syndrome, but the difference was not significant (34.7% versus 18.4%, P = .081). Also, there was no significant difference in SAA1 -13C/T allele frequency between AOSD patients with and without MEFV mutations.Our data shows a significant association between T allele of rs12218 and AOSD in Japanese population.

Placenta Specific 8 Suppresses IL-18 Production through Regulation of Autophagy and Is Associated with Adult Still Disease

Adult Still disease (ASD) is a systemic disorder of unknown etiology characterized by high spiking fever, rash, and arthritis. The purpose of this study was to identify genes specifically associated with the active phase of the disease. In this study, we have reported that placenta specific 8 (PLAC8) was a newly specific gene involved in ASD. DNA microarray and validation analysis using human monocytes revealed that the expression of PLAC8 was significantly higher in active-ASD patients than in inactive-ASD patients and healthy controls. In ASD, PLAC8 expression level correlated with serum levels of CRP, ferritin, IL-1β, and IL-18. Stimulation of monocytes with LPS results in PLAC8 upregulation. LPS or nigericin stimulation of PLAC8-overexpressing human monocytic cell line (THP-1), but not mock THP-1 cells, was associated with a significant decrease in IL-1β and IL-18 production. PLAC8 overexpression in THP-1 cells was associated with enhanced autophagy and suppression of IL-1β and IL-18 production. Therefore, we found that PLAC8 was upregulated in activated monocytes, as was IL-1β and IL-18. The upregulated PLAC8 acts on the synthesis of inactive precursors of IL-1β and IL-18 and seemed to suppress the production of IL-1β and IL-18 by negative feedback through enhanced autophagy, resulting in the suppression of ASD. The results highlight the role of PLAC8 in the pathogenesis of ASD and suggest its potential suitability as an activity marker and therapeutic target in ASD.

Anakinra Therapy for Non-cancer Inflammatory Diseases

Interleukin-1 (IL-1) is the prototypical inflammatory cytokine: two distinct ligands (IL-1α and IL-1β) bind the IL-1 type 1 receptor (IL-1R1) and induce a myriad of secondary inflammatory mediators, including prostaglandins, cytokines, and chemokines. IL-1α is constitutively present in endothelial and epithelial cells, whereas IL-1β is inducible in myeloid cells and released following cleavage by caspase-1. Over the past 30 years, IL-1-mediated inflammation has been established in a broad spectrum of diseases, ranging from rare autoinflammatory diseases to common conditions such as gout and rheumatoid arthritis (RA), type 2 diabetes, atherosclerosis, and acute myocardial infarction. Blocking IL-1 entered the clinical arena with anakinra, the recombinant form of the naturally occurring IL-1 receptor antagonist (IL-1Ra); IL-1Ra prevents the binding of IL-1α as well as IL-1β to IL-1R1. Quenching IL-1-mediated inflammation prevents the detrimental consequences of tissue damage and organ dysfunction. Although anakinra is presently approved for the treatment of RA and cryopyrin-associated periodic syndromes, off-label use of anakinra far exceeds its approved indications. Dosing of 100 mg of anakinra subcutaneously provides clinically evident benefits within days and for some diseases, anakinra has been used daily for over 12 years. Compared to other biologics, anakinra has an unparalleled record of safety: opportunistic infections, particularly Mycobacterium tuberculosis, are rare even in populations at risk for reactivation of latent infections. Because of this excellent safety profile and relative short duration of action, anakinra can also be used as a diagnostic tool for undefined diseases mediated by IL-1. Although anakinra is presently in clinical trials to treat cancer, this review focuses on anakinra treatment of acute as well as chronic inflammatory diseases.

Targeting cytokines to treat autoinflammatory diseases

Autoinflammatory diseases are rare group of conditions manifested by recurrent fevers, systemic inflammation, and dysfunctions of the innate immune system. These conditions are characterized by overproduction or lack of inhibition of various cytokines, and the advent of biologic drugs that block specific cytokines involved in these conditions has revolutionized their treatment. In this review, I will discuss the most common autoinflammatory conditions of adulthood including familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), mevalonate kinase deficiency/hyperimmunoglobulinemia D Syndrome (MKD/HIDS), TNF receptor-associated autoinflammatory syndrome (TRAPS), and systemic juvenile idiopathic arthritis/adult-onset Still's disease (SJIA/AOSD). I will discuss how IL-1, IL-6, IL-18, and TNF play pathogenic roles in these conditions and will review the evidence behind cytokine blockade for these diseases. Throughout the paper, I will reflect on gaps in knowledge of autoinflammatory diseases and will highlight the latest advances and newest drugs in development.

IL-6, IL-17 and Stat3 are required for auto-inflammatory syndrome development in mouse

Auto-inflammatory syndrome, a condition clinically distinct from rheumatoid arthritis, is characterized by systemic inflammation in tissues such as major joints, skin, and internal organs. Autonomous innate-immune activation is thought to promote this inflammation, but underlying pathological mechanisms have not been clarified nor are treatment strategies established. Here, we newly established a mouse model in which IL-1 signaling is conditionally activated in adult mice (hIL-1 cTg) and observed phenotypes similar to those seen in auto-inflammatory syndrome patients. In serum of hIL-1 cTg mice, IL-6 and IL-17 levels significantly increased, and signal transducer and activator of transcription 3 (Stat3) was activated in joints. When we crossed hIL-1 cTg with either IL-6- or IL-17-deficient mice or with Stat3 conditional knockout mice, phenotypes seen in hIL-1 cTg mice were significantly ameliorated. Thus, IL-6, IL-17 and Stat3 all represent potential therapeutic targets for this syndrome.

Anakinra for the treatment of adult-onset Still's disease

INTRODUCTION

Adult onset Still's disease (AOSD) is an uncommon systemic inflammatory disease on the clinical spectrum of autoinflammatory disorders. Its presentation and clinical course may result in several well-differentiated phenotypes: from a systemic and highly symptomatic pattern to a chronic articular pattern. Overproduction of numerous pro-inflammatory cytokines is observed in AOSD. Anakinra (ANK), a human interleukin (IL)-1R antagonist, has recently been approved in the EU for the treatment of AOSD. Areas covered: In this review, we discuss the main studies on the efficacy and safety on ANK for the treatment of AOSD. The vast majority of them are retrospective studies and case series. Expert commentary: Overall, ANK is an effective biologic agent for the treatment of AOSD, especially for the systemic pattern and also for those patients who have life-threatening complications, which frequently occur over the course of the disease. The initial dose usually indicated of ANK in adults is 100 mg/day subcutaneously, although dose reduction can be performed in some cases once the disease is under control. The safety profile of ANK is favorable and similar to that described in other rheumatic diseases. In conclusion, ANK is an effective and safe agent for the treatment of AOSD.

HLA-DQB1 DPB1 alleles in Japanese patients with adult-onset Still's disease

Objective: HLA class II alleles are major determinants of genetic predisposition to rheumatic diseases. Predisposing effects of HLA had been suggested in AOSD, however, ethnic differences may account for variations in AOSD association with HLA. We determined the contribution of HLA-DQB1, DPB1 alleles to susceptibility to Adult-onset Still's disease (AOSD) in the Japanese population. Methods: HLA-DQB1 and DPB1 alleles were analyzed in 87 Japanese patients with AOSD and 413 Japanese healthy subjects. Results: We found significant association between HLA-DQB1*06:02 (Pc = 0.010, odds ratio: 2.54) and AOSD, whereas there was no association between the DQB1*06:02 allele and disease phenotypes of AOSD. Moreover, we did not find a predisposing effect of the HLA-DPB1 allele to AOSD. Haplotype analysis showed that presence of DRB1*15:01-DQB1*06:02 was associated with Japanese patients with AOSD. However, conditional logistic regression tests were unable to demonstrate independent association between DRB1*1501 or DQB1*0602 and AOSD. Conclusions: Our results show significant association between AOSD and the HLA DQB1*06:02 allele, and between the DRB1*1501-DQB1*06:02 haplotype and AOSD susceptibility. These findings suggest that genetic susceptibility to AOSD depends on the genotype combinations of HLA DRB1 and DQB1 alleles.

Expand the differential…think beyond rheumatoid arthritis

A 31-year-old male patient with severe, migratory arthralgias presented to our academic medical centre after being erroneously diagnosed and treated for rheumatoid arthritis for over 1 year. Multiple immunomodulatory therapies for rheumatoid arthritis were attempted with no relief of symptoms. Eventually, the pain was so bothersome that the patient became bedridden for 1 month prior to presenting to our facility. Our assessment revealed that the patient met the diagnostic criteria, known as the Yamaguchi criteria, needed to diagnose adult-onset Still's disease. Yamaguchi criteria include migratory inflammatory arthritis, quotidian fevers, leucocytosis and a salmon-coloured maculopapular rash. These signs and symptoms may go unnoticed or overlooked if adult-onset Still's disease is not considered. The patient was treated with anakinra (a recombinant human IL-1 receptor antagonist) and had rapid improvement in his symptoms, with the restoration of mobility.

Adult-onset Still's disease with haemorrhagic pericarditis and tamponade preceded by acute Lyme disease

A 61-year-old Caucasian man presented with a fever of unknown origin, a transient erythematous rash on his right upper extremity and chest pressure after being treated for erythema migrans (Lyme disease). Echocardiogram demonstrated a large pericardial effusion with tamponade. He underwent pericardiostomy with tube placement. Workup for infectious and malignant etiologies was negative. Histology of the pericardium showed acute on chronic fibrinous haemorrhagic pericarditis. The patient met criteria for adult-onset Still's disease. Symptoms resolved following treatment with methylprednisolone and anakinra. We believe this is the first case of adult-onset Still's disease precipitated by acute Lyme disease.

A comprehensive review on adult onset Still's disease

Adult-onset Still's disease (AOSD) is a systemic inflammatory disorder of unknown etiology usually affecting young adults; spiking fever, arthritis and evanescent rash are commonly observed during the disease. Other frequently observed clinical features include sore throat, hepatomegaly, splenomegaly, lymphadenopathy and serositis. Furthermore, AOSD patients may experience different life-threating complications. Macrophage activation syndrome (MAS) has been reported up to 15% of AOSD patients and it is considered to be the most severe complication of the disease being characterised by high mortality rate. During AOSD, laboratory tests reflect the systemic inflammatory process showing high levels of erythrocyte sedimentation rate and C-reactive protein. In addition, the ferritin levels are typically higher than those observed in other autoimmune, inflammatory, infectious, or neoplastic diseases. Analysing AOSD disease course, 3 different clinical patterns of AOSD have been identified: i. monocyclic pattern, characterised by a systemic single episode; ii. polycyclic pattern, characterised by multiple, ≤ 1 year lasting, flares, alternating with remissions; iii. chronic pattern, related to a persistently active disease with associated polyarthritis. At present, AOSD therapeutic strategy is aimed at targeting pro-inflammatory signs and symptoms, preventing organ damage and life-threating complications and minimising adverse effects of treatment. However, the treatment of AOSD remains largely empirical, lacking controlled clinical trials. High dosages of corticosteroids are usually the first line therapy when the systemic symptoms predominate. Despite this treatment, a large percentage of patients experiences several flares with an evolution toward the chronic disease course and up to 16% of patients die during the follow up, due to AOSD-related complications. On these bases, in the last years, biological agents have been successfully used in refractory cases. Finally, multiple recent lines of evidence have suggested new insights in AOSD pathogenesis unmasking further therapeutic targets. In fact, small molecules, used in experimental MAS models, might represent new therapeutic options.

Open-label, multicentre, dose-escalating phase II clinical trial on the safety and efficacy of tadekinig alfa (IL-18BP) in adult-onset Still's disease

OBJECTIVES

Adult-onset Still's disease (AOSD) is a rare systemic autoinflammatory disease; its management is largely empirical. This is the first clinical study to determine if interleukin (IL)-18 inhibition, using the recombinant human IL-18 binding protein, tadekinig alfa, is a therapeutic option in AOSD.

METHODS

In this phase II, open-label study, patients were ≥18 years with active AOSD plus fever or C reactive protein (CRP) levels ≥10 mg/L despite treatment with prednisone and/or conventional synthetic disease-modifying antirheumatic drugs (DMARDs). Previous biological DMARD treatment was permitted. Patients received tadekinig alfa 80 mg or 160 mg subcutaneously three times per week for 12 weeks; those receiving 80 mg not achieving early predicted response criteria (reduction of ≥50% CRP values from baseline and fever resolution) were up-titrated to 160 mg for a further 12 weeks. The primary endpoint was the occurrence of adverse events (AEs) throughout the study.

RESULTS

Ten patients were assigned to receive 80 mg tadekinig alfa and 13 patients to the 160 mg dose. One hundred and fifty-five treatment-emerging AEs were recorded, and 47 were considered related to the study drug. Most AEs were mild and resolved after drug discontinuation. Three serious AEs occurred, one possibly related to treatment (toxic optic neuropathy). At week 3, 5 of 10 patients receiving 80 mg and 6 of 12 patients receiving 160 mg achieved the predefined response criteria.

CONCLUSIONS

Our results indicate that tadekinig alfa appears to have a favourable safety profile and is associated with early signs of efficacy in patients with AOSD.

TRIAL REGISTRATION NUMBER

NCT02398435.

Adding colchicine to immunosuppressive treatments; a potential option for biologics-refractory adult-onset Still's disease

Background

Adult-onset Still’s disease (AOSD) is a rare inflammatory disorder characterized by the classical triad of daily spiking fever, arthritis, and typical salmon-colored rash. Resistance to first-line corticosteroids and second-line disease modified anti-rheumatic-drugs defines refractory AOSD, which mostly includes the polycyclic or chronic courses of the disease. Anti-cytokine therapies are recommended in AOSD patients who are refractory to traditional treatments. This is the first report on the efficacy of colchicine in a patient with AOSD which was refractory to immunosuppressive treatments including biologics.

Case presentation

A 24-years Japanese female patient was referred to our hospital for the flare-up of AOSD under the combined treatments with steroid, immunosuppressants, and biologics. She was diagnosed with AOSD according to the Yamaguchi criteria, based on the presence of spiking fever, polyarthralgia, skin rash, and hyperferritinemia. Interleukin-6 or tumor necrosis factor-α blockade treatments were not effective, the oral administration of colchicine was stared under the immunosuppressive treatments with steroid and cyclosporine A (CyA). Colchicine treatment silenced the disease activity of AOSD. The dose of prednisolone was successfully tapered, and the elevated levels of C-reactive protein were normalized. Remission has been maintained for 13 months with the start of oral administration of colchicine.

Conclusion

We concluded that colchicine is an alternative treatment in patients with refractory AOSD, particularly in those with impaired therapeutic effects against anti-cytokines therapies.

Adult-onset Still's disease initially thought to be an odontogenic infection: A case report

OBJECTIVE

To present a case of Adult-onset Still's disease (AOSD) initially suspected to be odontogenic inflammation.

BACKGROUND

Adult-onset Still's disease is a rare, complex autoinflammatory disease and a known cause of fever of unknown origin.

MATERIALS AND METHODS

The patient had both a fever and dental pain. Following meticulous examination, the patient was diagnosed with AOSD.

CONCLUSION

Clinicians should keep in mind that a patient such as AOSD may visit their clinics.

Complications of adult-onset Still's disease and their management

INTRODUCTION

Adult-onset Still's disease (AOSD) is a rare systemic auto-inflammatory disorder in which management and treatment have considerably progressed over the past decade. Despite wide use of interleukin (IL)-1 or IL-6 inhibitors, serious complications remain possible. Areas covered: A comprehensive literature search in MEDLINE via Pubmed was performed to review AOSD's severe and sometimes life-threatening complications: reactive hemophagocytic lymphohystiocytosis, coagulation disorders, fulminant hepatitis, cardiac or pulmonary complications and amyloid A amyloidosis. Expert commentary: Early recognition and prompt management is essential to significantly decrease morbi-mortality. The key question is to determine whether the complication is related to the disease itself or related to or favored by (e.g. infection) the ongoing treatment. For all severe AOSD-related complications, high-dose corticosteroids and supportive measures remain the first-line treatment. In case of inadequate response, combination with IL-1 or IL-6 blockers is justified. Cyclosporine A and etoposide remain of interest, especially in case of reactive hemophagocytic lymphohysitocytosis. Plasma exchange may be useful in case of thrombotic microangiopathy. In the near future, new biologic or non-biologic drugs targeting IL-18 or other cytokines or kinases could be of help.

NLRP3 Inflammasome Activation Regulates Aged RBC Clearance

The NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome is triggered by various stimuli. Whether the NLRP3 inflammasome is activated during the monocyte clearing of aged or damaged erythrocytes is unknown. This work aimed to determine whether the NLRP3 inflammasome is activated during the THP-1 cell engulfing of aged erythrocytes. In the study, THP-1 cells were treated with PMA and then coincubated with untreated red blood cells (RBCs), 42 °C-treated RBCs, immunoglobulin G (IgG) anti-D-sensitized RBCs, Rhnull/Rhmod RBC sample, hemoglobin, and RBC ghost. The activation of the NLRP3 inflammasome and production of some proinflammatory cytokines were determined using immunoblotting, cytometric bead array, and digital PCR. An NLRP3 inflammasome inhibitor was also used to evaluate the alteration of the NLRP3 activation and RBC clearance rate. The untreated RBCs, 42 °C-incubated RBCs, IgG-opsonized RBCs, Rhnull/Rhmod RBCs, RBC ghosts, and hemoglobin induced the THP-1-cell-mediated activation of the NLRP3 inflammasome and the production of inflammatory cytokines. The RBC clearance rate exhibited a positive correlation with the expression of proinflammatory cytokines. The NLRP3 inflammasome inhibitor reduced the NLRP3 activation and RBC phagocytosis rate. The NLRP3 inflammasome was activated during the clearance of the aged erythrocytes through unopsonized and opsonized pathways. However, the mechanism of such phenomenon needs to be further elucidated. Such mechanism may provide new insight into the assessment of the safety of transfusing long-storage RBC based on cytokine levels.

Macrophage Activation Syndrome in Patients Affected by Adult-onset Still Disease: Analysis of Survival Rates and Predictive Factors in the Gruppo Italiano di Ricerca in Reumatologia Clinica e Sperimentale Cohort

OBJECTIVE

Macrophage activation syndrome (MAS) is a reactive form of hemophagocytic lymphohistiocytosis, which can complicate adult-onset Still disease (AOSD). We investigated AOSD clinical features at the time of diagnosis, to assess predictors of MAS occurrence. Further, we analyzed the outcomes of patients with AOSD who experience MAS.

METHODS

Patients with AOSD admitted to any Gruppo Italiano di Ricerca in Reumatologia Clinica e Sperimentale center were retrospectively analyzed for features typical of AOSD, MAS occurrence, and their survival rate.

RESULTS

Of 119 patients with AOSD, 17 experienced MAS (12 at admission and 5 during followup). Twelve patients with MAS at first admission differed from the remaining 107 in prevalence of lymphadenopathy and liver involvement at the time of diagnosis. In addition, serum ferritin levels and systemic score values were significantly higher in the patients presenting with MAS. At the time of diagnosis, the 5 patients who developed MAS differed from the remaining 102 in the prevalence of abdominal pain, and they showed increased systemic score values. In the multivariate analysis, lymphadenopathy (OR 7.22, 95% CI 1.49-34.97, p = 0.014) and abdominal pain (OR 4.36, 95% CI 1.24-15.39, p = 0.022) were predictive of MAS occurrence. Finally, MAS occurrence significantly reduced the survival rate of patients with AOSD (p < 0.0001).

CONCLUSION

MAS occurrence significantly reduced the survival rate in patients with AOSD. Patients with MAS at baseline presented an increased prevalence of lymphadenopathy and liver involvement, as well as high serum ferritin levels and systemic score values. The presence of lymphadenopathy and abdominal pain was associated with MAS occurrence.

Neutrophilic dermatoses: Pyoderma gangrenosum and other bowel- and arthritis-associated neutrophilic dermatoses

Neutrophilic dermatoses are a heterogeneous group of inflammatory skin disorders that present with unique clinical features but are unified by the presence of a sterile, predominantly neutrophilic infiltrate on histopathology. The morphology of cutaneous lesions associated with these disorders is heterogeneous, which renders diagnosis challenging. Moreover, a thorough evaluation is required to exclude diseases that mimic these disorders and to diagnose potential associated infectious, inflammatory, and neoplastic processes. While some neutrophilic dermatoses may resolve spontaneously, most require treatment to achieve remission. Delays in diagnosis and treatment can lead to significant patient morbidity and even mortality. Therapeutic modalities range from systemic corticosteroids to novel biologic agents, and the treatment literature is rapidly expanding. The second article in this continuing medical education series reviews the epidemiology, clinical characteristics, histopathologic features, diagnosis, and management of pyoderma gangrenosum as well as bowel-associated dermatosis-arthritis syndrome and the arthritis-associated neutrophilic dermatoses rheumatoid neutrophilic dermatitis and adult Still disease.

Diagnostic and management of life-threatening Adult-Onset Still Disease: a French nationwide multicenter study and systematic literature review

Background

Adult-onset Still disease (AOSD) is a rare systemic inflammatory disorder. A few patients develop organ complications that can be life-threatening. Our objectives were to describe the disease course and phenotype of life-threatening AOSD, including response to therapy and long-term outcome.

Methods

A multicenter case series of intensive care medicine (ICU) patients with life-threatening AOSD and a systematic literature review.

Results

Twenty patients were included. ICU admission mostly occurred at disease onset (90%). Disease manifestations included fever (100%), sore throat (65%), skin rash (65%), and arthromyalgia (55%). Serum ferritin was markedly high (median: 29,110 ng/mL). Acute respiratory failure, shock and multiple organ failure occurred in 15 (75%), 10 (50%), and 7 (35%) cases, respectively. Hemophagocytosis was demonstrated in eight cases. Two patients died. Treatment delay was significant. All patients received corticosteroids. Response rate was 50%. As second-line, intravenous immunoglobulins were ineffective. Anakinra was highly effective. After ICU discharge, most patients required additional treatment. Literature analysis included 79 cases of AOSD with organ manifestations, which mainly included reactive hemophagocytic syndrome (42%), acute respiratory failure (34%), and cardiac complications (23%). Response rate to corticosteroids was 68%. Response rates to IVIgs, cyclosporin, and anakinra were 50%, 80%, and 100%, respectively.

Conclusions

AOSD should be recognized as a rare cause of sepsis mimic in patients with fever of unknown origin admitted to the ICU. The diagnosis relies on a few simple clinical clues. Early intensive treatment may be discussed. IVIgs should be abandoned. Long-term prognosis is favorable.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2012-2) contains supplementary material, which is available to authorized users.

A case of adult onset Still's disease with mutations of the MEFV gene who is partially responsive to colchicine

RATIONALE

Familial Mediterranean fever (FMF) and adult onset Still's disease (AOSD) have overlapping features, and are categorized as being on the spectrum of autoinflammatory diseases (AIDs). FMF is more prevalent in the Mediterranean region but rarely, described in the Chinese population.

PATIENT CONCERNS

We present an interesting case of a Han Chinese AOSD patient with episodic fever, wheals, and polyarthritis for 2 years.

DIAGNOSIS

Sequencing analysis found exon 2 mutations of the MEFV gene (c.329T>C [L110P], and c.442G>C [E148Q]).

INTERVENTION

Her arthritis was well-controlled with colchicine treatment, but fever, and rashes were not.

OUTCOMES

She eventually received tocilizumab, in addition to colchicine, and her symptoms completely disappeared.

LESSONS

MEFV mutations may exist in AOSD patients, and treatment with colchicine might be helpful in such patients.

Severe Adult-onset Still Disease with Constrictive Pericarditis and Pleuritis That Was Successfully Treated with Tocilizumab in Addition to Corticosteroids and Cyclosporin A

Adult-onset Still disease (AOSD) is a systemic inflammatory disease characterized by fever, arthritis and rash. Corticosteroids represent a promising therapeutic option for AOSD; however, some resistant cases require immunosuppressants and biologic agents. We herein report the case of a 29-year-old Japanese man with severe AOSD, accompanied by constrictive pericarditis (CP) and pleuritis. Although 2 courses of steroid pulse and subsequent high-dose of prednisolone and cyclosporine A improved the patient's CP and pleuritis, his fever and inflammatory responses persisted. Tocilizumab (TCZ) was added to his treatment, which resulted in a rapid remission. This case suggests the usefulness of TCZ in the treatment of severe AOSD with CP and pleuritis.

Interleukin-37 is increased in adult-onset Still's disease and associated with disease activity

Background

Interleukin (IL)-37 has been known to play an immunosuppressive role in various inflammatory disorders, but whether it participates in the regulation of pathogenesis of adult-onset Still’s disease (AOSD) has not been investigated. In this study, we examined serum IL-37 levels and their clinical association with AOSD, and we explored the anti-inflammatory effects of IL-37 on peripheral blood mononuclear cells (PBMCs) from patients with AOSD.

Methods

Blood samples were collected from 62 patients with AOSD and 50 healthy control subjects (HC). The serum IL-37 levels were determined using an enzyme-linked immunosorbent assay (ELISA). The correlations of serum IL-37 levels with disease activity, laboratory values, and inflammatory cytokines in AOSD were analyzed by Spearman’s correlation test. The correlations between serum IL-37 levels and clinical manifestations were analyzed by Mann-Whitney U test. PBMCs from ten patients with AOSD were stimulated with recombinant human IL-37 protein, and expression levels of tumor necrosis factor (TNF)-α, IL-6, IL-10, IL-1β, and IL-18 were determined by qRT-PCR and ELISA.

Results

A significantly higher IL-37 protein level was observed in patients with AOSD than in HC. Serum IL-37 levels correlated with systemic score, laboratory values, IL-1β, IL-18, and IL-10 in patients with AOSD. The expression levels of IL-37 were closely related to the patients with AOSD who also had fever, skin rash, lymphadenopathy, splenomegaly, myalgia, and arthralgia. Moreover, the production of proinflammatory cytokines such as IL-6, IL-1β, TNF-α, and IL-18 in PBMCs from patients with AOSD was obviously attenuated after recombinant human IL-37 stimulation.

Conclusions

Increased expression of IL-37 and its positive correlation with disease activity suggest its involvement in AOSD pathogenesis. More importantly, IL-37 inhibits the expression of proinflammatory cytokines in PBMCs from patients with AOSD, indicating the potential anti-inflammatory role of IL-37 in AOSD. Thus, IL-37 may be a novel disease activity biomarker and research target in AOSD.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1555-6) contains supplementary material, which is available to authorized users.

Interleukin-1 Blockade: An Update on Emerging Indications

Interleukin (IL)-1 is a pro-inflammatory cytokine that induces local and systemic inflammation aimed to eliminate microorganisms and tissue damage. However, an increasing number of clinical conditions have been identified in which IL-1 production is considered inappropriate and IL-1 is part of the disease etiology. In autoinflammatory diseases, gout, Schnitzler's syndrome, and adult-onset Still's disease, high levels of inappropriate IL-1 production have been shown to be a key process in the etiology of the disease. In these conditions, blocking IL-1 has proven very effective in clinical studies. In other diseases, IL-1 has shown to be present in disease process but is not the central driving force of inflammation. In these conditions, including type 1 and 2 diabetes mellitus, acute coronary syndrome, amyotrophic lateral sclerosis, and several neoplastic diseases, the benefits of IL-1 blockade are minimal or absent.

Biological therapy of traditional therapy-resistant adult-onset Still's disease: an evidence-based review

Background

Biotherapy is becoming increasingly important in the treatment of adult-onset Still’s disease (AOSD). The aim of our study was to evaluate the efficacy and safety of biological therapy for AOSD resistant to traditional therapy.

Patients and methods

Database of Library of Congress, the PubMed, and Web of Science Core Collection were used to retrieve relevant articles published in English language until March 2017. Only studies published in English language were included, and the additional references quoted in these articles were also checked. Articles concerning the efficacy and safety of all the biotherapies in refractory AOSD were evaluated.

Results

There were 112 articles available in total; 422 AOSD patients were given at least one biologic. We found that 293 patients (69.43%) had received TNF-α blocking agents (infiliximab, etanercept, and adalimumab), 194 patients (45.97%) were treated with IL-1 receptor antagonists (anakinra, rilonacept, and canakinumab), 163 patients (38.63%) were given IL-6 inhibitor (tocilizumab), and 24 patients (5.69%) received rituximab and abatacept. The efficacy of biological therapy and overall tolerance of biological therapy for refractory AOSD were good. Thirty two of 271 patients given anti-TNF-α therapies (11.81%), 116 patients receiving IL-1 inhibitors (65.54%), 124 patients receiving tocilizumab (76.07%), and 13 patients given other biological therapies (36.11%) achieved remission. Side effects of biologic therapy were infections such as urinary tract infections and soft tissue abscess.

Conclusion

Our findings suggest that anakinra and tocilizumab may be good choices for the treatment of refractory AOSD considering the effectiveness and safety.

Approaches to sample size calculation for clinical trials in rare diseases

We discuss 3 alternative approaches to sample size calculation: traditional sample size calculation based on power to show a statistically significant effect, sample size calculation based on assurance, and sample size based on a decision-theoretic approach. These approaches are compared head-to-head for clinical trial situations in rare diseases. Specifically, we consider 3 case studies of rare diseases (Lyell disease, adult-onset Still disease, and cystic fibrosis) with the aim to plan the sample size for an upcoming clinical trial. We outline in detail the reasonable choice of parameters for these approaches for each of the 3 case studies and calculate sample sizes. We stress that the influence of the input parameters needs to be investigated in all approaches and recommend investigating different sample size approaches before deciding finally on the trial size. Highly influencing for the sample size are choice of treatment effect parameter in all approaches and the parameter for the additional cost of the new treatment in the decision-theoretic approach. These should therefore be discussed extensively.