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

Neutrophil activation biomarker pentraxin 3 for diagnosis and monitoring of macrophage activation syndrome occurrence in adult-onset Still's disease

Macrophage activation syndrome (MAS) is a potentially fatal consequence of adult-onset Still's disease (AOSD), driven by a cytokine storm. Efficient early diagnosis of AOSD-associated MAS requires a sensitive and specific biomarker. In this study, we demonstrated that pentraxin 3 (PTX3), an acute phase protein, was associated with AOSD disease activity and served as a biomarker for AOSD-MAS. PTX3 levels were significantly increased in AOSD patients compared to other autoimmune diseases and healthy controls. Plasma PTX3 levels showed positive correlations with inflammatory markers, the systemic score and the HScore. In active AOSD with MAS, PTX3 levels were higher compared to those in non-AOSD haemophagocytic lymphohistiocytosis (HLH) patients. Moreover, the PTX3's area under the curve value for distinguishing AOSD with MAS exceeded that of soluble interleukin-2 receptor, ferritin and C-reactive protein. Furthermore, plasma levels of PTX3 were associated with circulating NET-DNA levels. To fully understand the underlying mechanism of PTX3 prompting AOSD and AOSD-MAS progression, we discovered that neutrophils exhibited enhanced NET formation and mitogen-activated protein kinases (MAPK) pathway activation upon PTX3 stimulation. More importantly, PTX3-induced NET formation was effectively dampened by MAPK pathway inhibitors. These findings collectively revealed that PTX3 has a favorable correlation with disease activity and may serve as a potential biomarker to differentiate AOSD patients with MAS. Additionally, PTX3 induces NET release via the MAPK pathway, suggesting a pathogenic role in AOSD-MAS.

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.

Clinical characteristics and outcome of elderly onset adult-onset Still's disease: A 10-year retrospective study

Objective

Our objective was to retrospectively analyze the clinical characteristics and outcome of adult-onset Still's disease (AOSD) patients with elderly onset.

Methods

Retrospective data of patients diagnosed with AOSD in our institute during 2013-2021 were analyzed. The diagnoses were based on the Yamaguchi criteria for AOSD. All long-term follow-up data were collected from medical records and phone calls.

Results

In total, 281 AOSD patients were enrolled in this study, with the median follow-up interval of 47 months. Thirty-two (11.4%, ≥65 years) AOSD patients were classified into the elderly onset groups. Compared to the younger onset group, the percentage of patients with skin rash (p = 0.047), sore throat (p = 0.001), myalgia (p = 0.001), splenomegaly (p = 0.039), hepatosplenomegaly (p = 0.002) and the Pouchot's score (p = 0.002) were significantly lower in the elderly onset group. The death rate (p = 0.014) of elderly onset group is higher than younger onset group, and the independent risk factors of mortality in all AOSD patients were age at onset (HR: 1.115, p = 0.044), disseminated intravascular coagulation (HR: 391.576, p = 0.001) and pleuritis (HR: 23.162, p = 0.033). The probability of relapse was significantly increased in the patients with macrophage activation syndrome (MAS) compared with the patients without MAS (p < 0.001), though the different age groups of AOSD patients with MAS showed no difference in the probability of relapse (p = 0.737).

Conclusion

Elderly onset AOSD patients were distinguished by several distinct clinical features compared to younger onset AOSD patients. The frequency of relapse and complications were similar to that of AOSD patients with elderly or younger onset. A higher mortality rate was observed in elderly onset AOSD patients, and the mortality of AOSD patients was related to age at onset, DIC and pleuritis.

Development and validation of the AF score for diagnosis of adult-onset Still's disease in fever of unknown origin

Objective

To develop and validate a diagnostic score to identify adult-onset Still's disease (AOSD) in fever of unknown origin (FUO).

Methods

A single center, retrospective case-control study of inpatients with FUO from January 2018 to December 2021. Using clinical and laboratory data from 178 cases with AOSD and 486 cases with FUO, we developed an AOSD/FUO (AF) score with a Bayesian Model Averaging approach. AF score and Yamaguchi's criteria were evaluated by sensitivity, specificity, accuracy, and positive/negative predictive value for diagnosis of AOSD in developmental and validation samples.

Results

Persistent pruritic eruptions (PPEs) in patients with rashes was higher in AOSD group than FUO group (52.3% vs 7.4%; P < 0.01). PPEs yielded a specificity of 97.5% and a sensitivity of 44.9%. AF score = PPEs × 3.795+Evanescent rash × 2.774+Serum ferritin × 1.678+Myalgia × 0.958+Neutrophil count × 0.185+Platelet count × 0.004. A cut-off value ≥ 5.245 revealed the maximizing sensitivity of 88.7% and specificity of 95.8% in discriminating AOSD from FUO in the validation group. And AF score improved the accuracy from 82.6% to 93.3% compared with Yamaguchi's criteria.

Conclusions

We developed and validated a new score which can identify AOSD in FUO with higher classification accuracy than Yamaguchi's criteria. Future multi-centric prospective studies need to be designed to confirm the diagnosis value of AF score.

Still's disease with persistent atypical dermatomyositis-like skin eruption: two cases associated with macrophage activation syndrome

The typical rash of Still's disease is an asymptomatic, salmon-colored, macular, or maculopapular eruption that appears along with the fever spikes and fades when the body temperature drops. Although not included in the diagnostic criteria, there are other frequent, persistent, pruritic, and polymorphic skin manifestations of Still's disease that have distinctive clinical features and specific histological findings. Among these atypical persistent pruritic eruptions (PPEs), periorbital erythema and linear flagellate papules and plaques can resemble the cutaneous manifestations of dermatomyositis (DM). The presence of these lesions in adult-onset Still's disease has been associated with worse prognosis and higher mortality rates, perhaps due to the development of a secondary macrophage activation syndrome (MAS). We report two cases of Still's disease with persistent atypical DM-like eruption, one in a pediatric patient (a very underreported finding) and the other in an adult. Both cases developed a secondary MAS.

Serosal Involvement in Adult-Onset Still's Disease: A Multicenter and Retrospective Study

BACKGROUND

This study evaluated the characteristics of serosal involvement in Adult-onset Still's disease.

METHODS

Patients meeting the Yamaguchi classification criteria were classified into AOSD with and without serosal involvement according to their manifestations and sonography/radiography. Clinical data were retrospectively reviewed from 102 AOSD patients of two centers.

RESULTS

Forty-two patients (41.2%) had serosal involvement. The frequencies of pulmonary infiltrate and impaired liver function were significantly higher in patients with serosal involvement (P=0.002 and P=0.007, respectively), who also had a higher modified systemic score (P=0.009). In addition, the percentages of CD3+ T cells (P<0.0001) and, especially, the CD8+ T cells (P=0.004) were significantly increased in the peripheral blood of AOSD patients with serosal involvement. Notably, patients with serosal involvement were more likely to develop MAS (P=0.047) and develop into chronic pattern (P=0.016) during the follow-up.

CONCLUSION

Patients with serosal involvement demonstrated the more severe disease activity and different immune phenotypes, and these patients were more likely to develop MAS, and they may require more aggressive treatment at an early time to control their systemic inflammation.