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.

Serum VEGF-C as an evaluation marker of disease activity in adult-onset Still's disease.

In view of the possible involvement of vascular endothelial growth factor-C (VEGF-C) in pathogenesis of adult-onset Still's disease (AOSD) based on our previous genome-wide association study (GWAS) results, the primary objective of this study, therefore, was to investigate the correlations between the content of VEGF-C in serum and clinical and biochemical markers of AOSD. Blood samples were collected from 80 patients with AOSD, 26 with rheumatoid arthritis (RA), 30 with systemic lupus erythematosus (SLE) and 31 healthy control subjects. The serum VEGF-C levels were determined using an enzyme-linked immunosorbent assay (ELISA). Statistical analysis and comparisons were conducted. A significantly higher serum VEGF-C level was observed in patients with AOSD than in HC. Serum VEGF-C levels had high AUC value of 0.8145 for distinguishing AOSD group from healthy group with sensitivity of 0.7097 and specificity of 0.8250. It also showed good diagnostic value to differentiate AOSD from other autoinflammatory diseases with sensitivity of 0.7500 and specificity of 0.5500. AOSD patients with fever, arthralgia, skin rash, sore throat, lymphadenopathy, splenomegaly hepatomegaly and pleuritis, had a higher level than those who did not have these symptoms (p = 0.0012, p = 0.0092, p = 0.0056, p = 0.0123, p = 0.0068, p = 0.0030, p = 0.0020, and p = 0.0018, respectively). The serum VEGF-C levels were also positively correlated with laboratory features and several cytokines related to AOSD disease activity. In conclusion, our study unveiled a close association between serum VEGF-C levels and AOSD including disease activity and clinical hematological manifestations, suggesting the potential utility of VEGF-C as a candidate biomarker to assess disease activity in AOSD.

Regulatory and other rheumatoid factors in rheumatoid arthritis patients with active disease or in remission.

BACKGROUND: Previously, we identified a regulatory rheumatoid factor (regRF), the production of which provides rats with resistance to collagen-induced arthritis (CIA). Immunization with conformers of IgG Fc fragments carrying epitopes specific to regRF reduces symptoms of CIA. The aim of this study was to determine whether there is a link between regRF levels and rheumatoid arthritis (RA) activity in humans in order to assess the potential of regRF as a therapeutic biotarget in RA. The variability of rheumatoid factor (RF) specificities present in the blood of RA patients was also studied. METHODS: The regRF were studied in RA patients with active disease and in remission. Variability in the specificities of RF associated with RA was studied by concurrent inhibition of RF latex fixation by variants of modified IgG. RESULTS: Patients in remission had regRF levels higher than in healthy subjects. The regRF in remission was characterized by tight binding to its antigen, as in healthy subjects. The regRF levels in patients with active RA varied dramatically, and regRF binding to its antigen was weak. The exacerbation of Still's disease coincided with low regRF levels and affinity, while an improvement in patient condition was associated with an increase in regRF levels and affinity. The RF specific to RA, which was detected by the RF latex-fixation method, was a nonhomogeneous population of antibodies that included RF to lyophilized IgG, to IgG immobilized on polystyrene, and to rabbit IgG. CONCLUSION: Stimulating regRF production might enable improved RA therapy.

Circulating regulatory T cells in adult-onset Still's disease: Focusing on their plasticity and stability.

We investigated the characteristics of regulatory T cells in adult-onset Still's disease (AOSD) with a focus on their plasticity, stability and relationship to disease severity. The proportion of circulating CD4+ CD25+ forkhead box protein 3 (FoxP3+ ) cells (Tregs ) and intracellular expression of effector cytokines, including interferon (IFN)-γ, interleukin (IL)-17 and IL-4, was analysed in 27 untreated patients with AOSD (acute AOSD), 11 of the 27 patients after remission and 16 healthy controls (HC) using flow cytometry. The suppressive ability of Tregs was also evaluated. Regression analyses of the results were performed. The proportion of Tregs was significantly lower in patients with acute AOSD than in the HC. The expression levels of IFN-γ, IL-17 and IL-4 in Tregs were significantly increased in patients with acute AOSD. IFN-γ and IL-4 expression levels were inversely correlated with the proportion of Tregs and positively correlated with serum ferritin levels. Decreased expression of FoxP3 in CD4+ CD25+ cells, which was correlated with increased expression of IL-17, and impaired suppressive function were observed in Tregs in acute AOSD. However, these aberrant findings in Tregs , including the reduced circulating proportion and functional ability and altered intracellular expression levels of cytokines and FoxP3, were significantly improved after remission. In acute AOSD, Tregs show plastic changes, including effector cytokine production and reductions in their proportion and functional activity. IFN-γ and IL-4 expression levels in Tregs may be associated with disease severity. Also, down-regulation of FoxP3 may be related to IL-17 expression in Tregs . Importantly, the stability of Tregs can be restored in remission.

Elevated circulating pro-inflammatory low-density granulocytes in adult-onset Still's disease.

OBJECTIVES: Neutrophilia is a hallmark of adult-onset Still's disease (AOSD). This study aimed to investigate the role of a distinct subset of granulocytes, the low-density granulocytes (LDGs) in the pathogenesis of AOSD. METHODS: A total of 56 patients with AOSD were included in the study. LDGs were quantified by flow cytometry. Correlations between LDGs with disease activity and laboratory parameters were determined by Spearman's nonparametric test. The cellular sources of the pro-inflammatory cytokines in AOSD were determined by intracellular staining. RESULTS: Active AOSD patients displayed significantly higher levels of LDGs compared with inactive AOSD patients and healthy controls (HCs) (P<0.001). Circulating LDGs were significantly correlated with CRP, ESR and the modified Pouchot score in patients with AOSD (P<0.01). The levels of LDGs were significantly decreased after the active AOSD patients achieved disease remission (P=0.0391). CD14+ monocytes constituted over 90% IL-1ß+ peripheral blood mononuclear cells (PBMCs) and over 80% TNF-α+ PBMCs in both active AOSD patients and HCs, respectively. In active AOSD, CD14+ monocytes accounted for 24.6% to 75.0% of IL-6+ PBMCs, while LDGs comprised 22.8% to 72.2% of IL-6+ PBMCs. In contrast, over 90% IL-6+ PBMCs were CD14+ monocytes in HCs. A significant correlation was identified between the levels of LDGs and serum IL-6 levels in AOSD (P<0.0001). CONCLUSION: Active AOSD is associated with elevated levels of a pro-inflammatory subset of neutrophils, the LDGs that produce IL-6. Our data highlight an unappreciated role of LDGs in the aberrant innate immune responses in AOSD.

Neutrophil-derived lipocalin-2 in adult-onset Still's disease: a novel biomarker of disease activity and liver damage.

OBJECTIVE: Liver damage is a common manifestation and can be life-threatening in adult-onset Still's disease (AOSD), an autoinflammatory disease. The hallmark of AOSD is activation of neutrophils, whose infiltration in liver is suspected to promote tissue injury. Here we aimed to identify a candidate biomarker and to validate its association with liver damage in AOSD. METHODS: Transcriptome analysis of neutrophils from treatment-naïve active AOSD patients and healthy donors was performed. Lipocalin-2 (LCN2) expression was assessed in neutrophils, plasma and liver biopsies of AOSD. The correlations of LCN2 with different variables and its ability to identify liver damage from AOSD patients were analysed. RESULTS: LCN2, a novel biomarker in hepatic inflammation, was found to be upregulated in AOSD neutrophils by RNA sequencing and confirmed at the mRNA and protein levels. Plasma levels of LCN2 were significantly higher in AOSD patients than healthy controls, RA and SLE patients. Plasma LCN2 levels were closely correlated with inflammatory markers, systemic score, HScore and cytokines. Moreover, LCN2 levels were increased in active AOSD with liver involvement and independently associated with liver dysfunction. Enhanced expression of LCN2 was detected in liver biopsies from three patients with ongoing liver injury. Furthermore, the area under the curve value of LCN2 for identifying AOSD with liver injury from other liver diseases was 0.9694. CONCLUSION: Our results reveal that neutrophils-derived LCN2 is higher in plasma and liver tissue in AOSD patients than in healthy controls, and it could serve as a potent biomarker for identifying AOSD with systemic inflammation, especially liver damage caused by hyperinflammation.

Biomarker screening and validation for the differentiation of bloodstream infection from adult-onset Still's disease: A prospective cohort study.

OBJECTIVES: Distinguishing between bloodstream infection (BSI) and adult-onset Still's disease (AOSD) is challenging in practice due to similarities in their clinical and laboratory characteristics. We aimed to identify biomarkers in a prospective cohort of patients with BSI and AOSD for differential diagnosis and prognosis prediction. METHODS: Sixty-four individuals were enrolled in the training set (37 with BSI, 17 with AOSD, and 10 healthy controls). Furthermore, 86 individuals were enrolled in the validation cohort (67 with BSI and 19 with AOSD). Clinical and laboratory data were collected. Blood samples were stimulated using bacteria-specific antigens and levels of several cytokines were detected in the supernatant via Luminex or enzyme-linked immunosorbent assay. RESULTS: Escherichia coli and Klebsiella pneumoniae were the pathogens most frequently responsible for BSI. In the training cohort, the incidence of rash, arthralgia, myalgia, sore throat, lymphadenopathy, leukocytosis, and hyperferritinemia was higher in patients with AOSD than in those with BSI. Procalcitonin was significantly higher in patients with BSI than that in those with AOSD. Interleukin (IL)-6, IL-17A, C-X3-C motif chemokine ligand (CX3CL)-1, and C-X-C motif chemokine ligand 10 (CXCL10) levels were higher in patients with BSI than in those with AOSD. IL-18 was higher among patients with AOSD than in those with BSI. A decision tree analysis showed that a combination of plasma IL-18 and ferritin levels can be used to distinguish BSI from AOSD (diagnostic accuracy: 97.67%, sensitivity: 96.15%, specificity: 100%). Plasma IL-18 levels were positively correlated with ferritin, and were decreased after treatment in both BSI and ASOD groups. CONCLUSIONS: Plasma IL-18 and ferritin levels can be used to differentiate BSI from AOSD. IL-18 may be a potential biomarker for prognosis prediction in BSI and AOSD.

Dual effects of interleukin-10 on natural killer cells and monocytes and the implications for adult-onset Still's disease.

OBJECTIVES: We compared the serum levels of multiple cytokines in patients with adult-onset Still's disease (AOSD) and healthy controls to assess the effects of humoral factors on natural killer (NK) cells and monocytes. METHODS: We quantified the serum levels of 10 cytokines in the patients using bead-based multiplex immunoassays, along with interleukin (IL-)18 using ELISA. We then sorted NK cells and monocytes from the peripheral blood mononuclear cells (PBMCs) of healthy volunteers, cultured them in the presence or absence of cytokines that were detected in some or all of the serum samples from the AOSD patients and their combinations in vitro, and analysed the culture supernatant. RESULTS: IL-6 and IL-18 were the main cytokines increased in the serum of AOSD patients. When NK cells were cultured with the cytokines and IL-10, the combination of IL-10 and IL-18 substantially induced interferon (IFN-)γ. IL-6 had little effect on NK cells, probably because they barely expressed the IL-6 receptor and glycoprotein 130 (gp130). IFN-γ induced monocytes to produce IL-1ß, IL-6 and tumour necrosis factor (TNF-)α whereas IL-10 inhibited the induction of these proinflammatory cytokines. CONCLUSIONS: IL-10 evidently has dual effects on NK cells (stimulation) and on monocytes (inhibition). Better understanding the roles of the cytokine network would shed light on the pathogenesis of AOSD.

Ferritin, fever, and frequent visits: Hyperferritinemic syndromes in the emergency department.

Fever of unknown origin (FUO) is defined as persistent fevers without an identifiable cause despite extensive medical workup. Emergency physicians caring for patients reporting a persistent, nonspecific, febrile illness should carefully consider potentially serious non-infectious causes of FUO. We present a case of a 35-year-old man who presented to the emergency department (ED) three times over a 10-day period for persistent febrile illness and was ultimately diagnosed with Adult-Onset Still's Disease (AOSD) after a serum ferritin level was found to be over 42,000 µg/L. AOSD, along with macrophage activation syndrome, catastrophic antiphospholipid syndrome, and septic shock comprise the four hyperferritinemic syndromes. These are potentially life-threatening febrile illnesses that characteristically present with elevated ferritin levels. In this article, we highlight the value of a serum ferritin level in the workup of a patient with prolonged febrile illness and its utility in facilitating early diagnosis and prompt treatment of hyperferritinemic syndromes in the ED.

Serum sTREM-1 in adult-onset Still's disease: a novel biomarker of disease activity and a potential predictor of the chronic course.

OBJECTIVES: Triggering receptor expressed on myeloid cells-1 (TREM-1) is an amplifier of inflammatory signals. Recently, a soluble form of TREM-1 (sTREM-1) was described. This study aimed to investigate the role of serum sTREM-1 in patients with adult-onset Still's disease (AOSD). METHODS: Serum sTREM-1 levels were detected in 108 AOSD patients, 88 RA patients and 112 healthy controls (HC). The correlations of sTREM-1 with disease activity, clinical characteristics and laboratory parameters in AOSD patients were analysed by the Spearman correlation test. Risk factors for the chronic course of AOSD were evaluated by multivariate logistic regression analysis. RESULTS: AOSD patients had significantly higher serum sTREM-1 levels than RA patients and HC, and serum sTREM-1 levels were correlated with the systemic score, ferritin, leucocyte count, CRP, IL-1ß and IL-6. The elevation in the initial sTREM-1 level by itself could discriminate patients developing the chronic course from patients developing the nonchronic course. Moreover, an elevated sTREM-1 level (> 526.4475 pg/ml) was an independent risk factor for the chronic course in active AOSD patients. Furthermore, interfering with TREM-1 engagement led to reductions in the secretion of pro-inflammatory cytokines, such as IL-1ß, IL-6 and TNF-α, in neutrophils and monocytes from active AOSD patients. CONCLUSION: Serum sTREM-1 levels are correlated with disease activity, and an elevation in the initial serum sTREM-1 level is a potential predictor of the chronic course in AOSD patients, which currently provides the best predictive model for identifying patients prone to developing the chronic course of AOSD.

Effectiveness of Profiling Serum IL-18 and Neopterin in Diagnosis of Adult-Onset Still's Disease Complicated by Pulmonary Tuberculosis: A Case Report.

Adult-onset Still's Disease (AOSD) is a systemic inflammatory disorder characterized by high fever, skin rashes, and joint pains, and is extremely rare in patients over 80 years of age. An 88-year-old woman was admitted with high fever lasting for > 2 weeks and arthritis of the right knee and bilateral wrists. Further examination revealed that the patient fulfilled the Yamaguchi criteria, the most sensitive and extensively used classification criteria for AOSD. After ruling out other causes and considering a greatly raised serum interleukin-18 (IL-18) level, the patient was diagnosed with AOSD. Before prednisolone therapy, active tuberculosis was excluded using chest computed tomography (CT) and an interferon-gamma release assay (IGRA). After starting the treatment, serum levels of IL-18 and acute-phase reactants were decreased gradually. However, during prednisolone tapering, fever relapsed along with increasing serum acute phase reactant levels. Her serum IL-18 level was decreased but remained at a high level, and the neopterin level was further increased. These findings suggested the onset of another disease, but not AOSD recurrence. A chest CT scan revealed new lung infiltrates. Despite the initial negative IGRA result, cultures and polymerase chain reaction tests of bronchoalveolar lavage and sputum were positive for Mycobacterium tuberculosis. She was placed on a 9-month course of anti-tuberculosis therapy and continued prednisolone tapering. She showed steady improvement and her cytokine profile showed a decrease in the IL-18 and neopterin levels. In conclusion, cytokine profiling is useful in making the diagnosis of AOSD and subsequent pulmonary tuberculosis developed during steroid therapy.

The role of low density granulocytes and NETosis in the pathogenesis of adult-onset Still's Disease.

OBJECTIVES: To analyse the potential contribution of low-density granulocytes (LDGs) and NETosis, as well as the differential protein cargo of neutrophil extracellular traps (NETs), as physiopathogenic mechanisms of adult-onset Still's disease (AOSD). METHODS: We recruited 30 patients with AOSD according to the Yamaguchi diagnostic criteria. LDGs were addressed by multiparametric flow cytometry as those CD14-, CD15+, CD10+ cells in the peripheral blood mononuclear cells fraction. NETs were quantified by ELISA, immunofluorescence and fluorescence spectrometry. The expression of LL-37 and high mobility group box 1 (HMGB-1) in NETs was measured by immunofluorescence and confocal microscopy. Additionally, normal density neutrophils from healthy controls were stimulated with serum from patients with AOSD and NET induction was assessed by immunofluorescence. RESULTS: Patients with active disease as well as those with arthritis, cutaneous manifestations and fever had a higher amount of NETs and LDGs. Serum NETs from AOSD patients correlated with the number of swollen joints (r=0.41, p=0.032), absolute number of monocytes (r=0.529, p=0.005). The spontaneous NETs from patients with cutaneous manifestations and fever had higher cargo of HMGB-1 compared with patients in remission. CONCLUSIONS: LDGs and NETs are increased in patients with active AOSD and correlate with particular clinical features. Patients with cutaneous lesions and fever present a higher cargo of HMGB1 in their spontaneous NETs.

Predictive factors and prognosis of macrophage activation syndrome associated with adult-onset Still's disease.

OBJECTIVES: To summarise the clinical data of adult-onset Still's disease (AOSD) patients and analyse their clinical manifestations, predictors for the formation and prognosis of macrophage activation syndrome (MAS). METHODS: A retrospective analysis was performed on the clinical data of 182 AOSD hospitalised patients from the Department of Rheumatology of the First Affiliated Hospital of Zhengzhou University, China from January 2012 to August 2018, including 11 patients with pathogenesis of MAS. RESULTS: Compared with the patients without MAS, the patients with MAS had a higher incidence of splenomegaly and pericarditis at the initial diagnosis of AOSD. The number of platelets (PLT) and the concentration of fibrinogen (FIB), D-Dimer and ferritin were significantly higher in AOSD-MAS patients. Multivariate regression analysis showed that splenomegaly (OR: 5.748, 95% CI: 1.378-23.984, p=0.016), pericarditis (OR: 6.492, 95% CI: 1.43-29.461, p=0.015), and ferritin >2000 µg/L (OR: 4.715, 95% CI: 1.12-19.86, p=0.035) were risk factors for MAS. Survival analysis indicated that the mortality of AOSD-MAS patients was significantly higher than patients without MAS. CONCLUSIONS: Splenomegaly, pericarditis and elevated ferritin concentration are risk factors for MAS formation in AOSD patients. MAS resulted in a significant decrease in the survival rate of the AOSD patients.

The levels of CXCL12 and its receptor, CXCR4, as a biomarker of disease activity and cutaneous manifestation in adult-onset Still's disease.

OBJECTIVES: This study evaluated the SDF-1/CXCL12 and soluble CXCR4 (sCXCR4) levels, and investigated their clinical relevance in adult-onset Still's disease (AOSD). METHODS: Forty-two AOSD patients and 30 healthy controls (HC) were enrolled for serum sampling. Expression levels of CXCL12 and CXCR4 in skin biopsy materials of 40 AOSD patients, 10 patients with eczema, or 10 psoriasis, and 10 HC skin were evaluated with immunohistochemistry. RESULTS: The serum CXCL12 levels in patients with AOSD (2,452±1,531 pg/mL) were higher than those in HC (1,708±1,322 pg/mL, p=0.017). The serum sCXCR4 levels in patients with AOSD (14,449±16,627 pg/mL) were higher than those in HC (3,046±2,554 pg/mL, p<0.001). Serum CXCL12 levels correlated positively with counts of leukocytes and neutrophils, erythrocyte sedimentation rate, ferritin, and C-reactive protein (CRP). Serum sCXCR4 levels correlated positively with systemic scores, platelet counts, and CRP levels. The serum levels of CXCL12 and sCXCR4 were decreased significantly in the patients with AOSD followed after resolution of disease activity. On immunohistochemical stain, the mean percentage of CXCR4-positive inflammatory cells was 51.4±27.5% and that of CXCL12-positive inflammatory cells was 16.7±13.3% in AOSD patients. CXCR4 was more frequently expressed in inflammatory cells from AOSD patients than in those with eczema or psoriasis and HC skin. CONCLUSIONS: These results provide that sCXCR4 could be a clinical biomarker of evaluation for disease activity in AOSD, and show that CXCR4/CXCL12 may influence the inflammatory condition and skin manifestations of AOSD.

Beneficial use of serum ferritin and heme oxygenase-1 as biomarkers in adult-onset Still's disease: A multicenter retrospective study.

BACKGROUND: Heme oxygenase (HO)-1 is a heme-degrading enzyme highly expressed in monocyte/macrophage, serum levels of which may be promising biomarker for adult-onset Still's disease (AOSD). We here report data on the use of serum ferritin and HO-1 levels in AOSD. METHODS: Under the Hypercytokinemia Study Group collaboration, we collected sera from a total of 145 AOSD patients. Three independent experts judged whether the patients were definite AOSD depending on the clinical information. These 91 'definite AOSD' patients were further divided into active, remission, and relapse groups. Forty-six cases of systemic vasculitis, sepsis, etc. were included as disease controls. Serum ferritin and HO-1 levels were measured using ELISA. Associations between clinical symptoms, serum ferritin, and HO-1 were explored. Multivariate regression analysis was performed to identify independent variables associated with definite AOSD diagnosis. RESULTS: Serum ferritin and HO-1 levels were significantly higher in active and relapsed AOSD cases compared to disease controls, and were reduced by the treatment. Although a significant correlation was found between serum ferritin and HO-1 levels, a discrepancy was found in some cases such as iron-deficiency anemia. Receiver operating characteristic analysis identified optimal levels of serum ferritin (>819 ng/ml; sensitivity 76.1% and specificity 73.8%), and serum HO-1 (>30.2 ng/ml; sensitivity 84.8% and specificity 83.3%) that differentiated AOSD from controls. Interestingly, 88.9% of patients with AOSD who relapsed exceeded the cut-off value of serum HO-1 > 30.2 ng/ml, but only 50.0% exceeded serum ferritin >819 ng/ml (p = .013), suggesting that serum HO-1 levels may be a convenient indicator of AOSD disease status. Multivariate analysis identified neutrophilia, RF/ANA negativity, sore throat, and elevated serum HO-1 as independent variables associated with AOSD diagnosis. CONCLUSION: We confirmed that serum ferritin and HO-1 serve as highly specific and sensitive biomarkers for AOSD. A future prospective study with large sample size is necessary to determine whether these biomarkers could be included in Yamaguchi's Criteria.

Highly Expression of CD11b and CD32 on Peripheral Blood Mononuclear Cells from Patients with Adult-Onset Still's Disease.

BACKGROUND: We investigated the potential role of several pattern-recognition receptors (PRRs; CD11b, CD11c, CD32, CD206, CD209, and dectin-1) in adult-onset Still's disease (AOSD). METHODS: The study included 13 untreated AOSD patients, 19 rheumatoid arthritis (RA) patients (as a disease control), and 19 healthy controls (HCs). The PRRs were quantified in peripheral blood using flow cytometry. The serum levels of interleukin-17 (IL-17), IL-18, and IL-23 were measured by enzyme-linked immunosorbent assay. RESULTS: Significantly higher mean frequencies of cells presenting CD11b and CD32 from whole blood were observed in patients with AOSD than in patients with RA or HC. The levels of IL-17, IL-18, and IL-23 were elevated in AOSD patients compared to HCs. CD11b frequencies from whole cells correlated with systemic scores, lactate dehydrogenase (LDH) levels, aspartate transaminase levels, interleukin-23 (IL-23) levels, and IL-18. Frequencies of CD209 from granulocytes were significantly correlated with systemic scores, and the erythrocyte sedimentation rate and levels of C-reactive protein, ferritin, LDH, IL-23, and interleukin-18 (IL-18). CONCLUSIONS: Elevated frequencies of circulating CD11b-positive cells and positive correlations with disease activity markers suggest that circulating CD11b-positive cells contribute to the pathogenesis of AOSD.

[Diagnosis and treatment for one case of elderly diabetes complicated with Still's disease].

Adult onset Still's disease (AOSD) is a clinical syndrome with multiple organ failure. The patients normally show intermittent high fever for a long time, a transient rash, arthritis or joint pain as the main performance, accompanied by an increase in granulocytes and enlargement in liver, spleen and lymph node. A 71-years-old female patient with type 2 diabetes admitted hospital because of high fever, skin rash, joint pain and increased granulocyte. After review of the iron protein, she was diagnosed as AOSD. We found that clinicians need to improve the understanding for this disease in order to make the early diagnosis, especially in elderly patients with diabetes mellitus. In such patients, ferritin may not be high at early time. However, when the symptoms and signs are consistent with clinical manifestations, and anti-infection treatment effect is poor, we should pay attention to the disease, and repeated review of ferritin is necessary to assist the early diagnosis.

Cytokine profile in adult-onset Still's disease: Comparison with systemic juvenile idiopathic arthritis.

To compare pro-inflammatory cytokine profiles and kinetics in patients with adult-onset Still's disease (AOSD) to those in patients with systemic juvenile idiopathic arthritis (s-JIA), we analyzed serum cytokine concentrations in 33 patients with AOSD and 77 patients with s-JIA and compared them with clinical features. Patients with AOSD and s-JIA shared a common cytokine profile pattern of a significant increase in IL-18. Patients with AOSD were classified into two subgroups based on serum IL-6 and IL-18 levels. The number of patients with arthritis was significantly higher in the IL-6-dominant subgroup. The cytokine patterns associated with s-JIA and AOSD share common features, such as a significant and predominant increase in IL-18. Distinct IL-6- and IL-18-based cytokine profiles might be responsible for distinct clinical manifestations. The presence of two distinct subgroups in patients with both diseases further supports the view that s-JIA and AOSD share a disease category.

Elevated serum levels of free interleukin-18 in adult-onset Still's disease.

OBJECTIVE: IL-18 is a pro-inflammatory cytokine of the IL-1 family that is naturally inhibited by IL-18 binding protein (IL-18BP). High levels of IL-18 have been described in the serum of adult-onset Still's disease (AOSD) patients, but only total IL-18 levels (including inactive IL-18 bound to IL-18BP) have been measured. With a specific immunoassay, we aimed to measure free IL-18 serum levels in AOSD patients and other rheumatic diseases. METHODS: An ELISA was developed to measure free IL-18. Its sensitivity and specificity were tested by spiking recombinant IL-18 or IL-18BP in serum and PBS supplemented with 5% BSA. The binding affinity of IL-18 to IL-18BP was calculated by titration experiments using the ELISA and by Biacore analysis. Sera of 37 AOSD patients and 138 controls (40 healthy controls, 30 RA, 29 SLE, 21 AS and 18 PsA) were assayed for free IL-18, IL-18BP, total IL-18 and other cytokines. Correlations were performed between free IL-18 and markers of disease activity in AOSD patients. RESULTS: Free IL-18 serum levels were significantly higher in AOSD patients (median 8.89 pg/ml) than in healthy and disease controls (1.37 pg/ml; P < 0.01). Free IL-18 serum levels correlated with AOSD activity. The affinity of IL-18 to IL-18BP was found to be much higher than previously described, with a dissociation constant ranging from 30 to 50 pM. CONCLUSION: Free IL-18 levels are specifically elevated in AOSD compared with other inflammatory diseases, suggesting that IL-18 represents a potential target for the treatment of AOSD.

Efficacy of tocilizumab therapy in Korean patients with adult-onset Still's disease: a multicentre retrospective study of 22 cases.

OBJECTIVES: To evaluate the efficacy of tocilizumab (TCZ), a monoclonal antibody against the interleukin (IL)-6 receptor, for refractory adult-onset Still's disease (AOSD) in the Korean population. METHODS: This retrospective study included 22 Korean patients with refractory AOSD who were given TCZ at one of seven university hospital-based clinics for rheumatic disease. Patients were subdivided into groups according to disease course: monocyclic, systemic polycyclic, and chronic articular. Modified Pouchot scores, including laboratory and clinical findings, were analysed at 6 months and 12 months. RESULTS: TCZ was given at 4-8 mg/kg every 4-5 weeks (8 mg/kg every 4-5 weeks in 18 patients, 6 mg/kg every 4 weeks in 2, and 4 mg/kg every 4 weeks in 2) for 7.5 months (median, IQR: 4.0-12.3). A good response (measured as a decrease of >2 in the modified Pouchot score) was achieved in 50.0% of patients (11 of 22) at 6 months and in 64.3% (9 of 14) at 12 months. The dose of corticosteroid dose was reduced from 11.5 mg/day (median, IQR: 10.0-21.3) immediately before TCZ therapy to 7.5 mg/day (median, IQR: 5.0-10.0, p=0.002) at 6 months and finally to 6.3 mg/day (median, IQR: 5.0-7.5, p=0.002) at 12 months. Only one patient discontinued TCZ treatment due to facial swelling accompanied by high blood pressure. In all others, adverse events subsided with delayed TCZ therapy, and TCZ therapy was continued successfully without problems. CONCLUSIONS: TCZ was effective for treating Korean AOSD patients who were refractory to conventional therapy or other anti-cytokine biologics, showing a corticosteroid-sparing effect and an acceptable tolerance profile.