Clinical and laboratory features,treatment,and outcomes of macrophage activation syndrome in 80 children:a multi-center study in China

Background Macrophage activation syndrome(MAS)is a major cause of morbidity and mortality in pediatric rheumatology.We aimed to further understand the clinical features,treatment,and outcome of MAS in China.Methods A multi-center cohort study was performed in seven hospitals in China from 2012 to 2018.Eighty patients with MAS were enrolled,including 53 cases with systemic juvenile idiopathic arthritis(SJIA-MAS),10 cases of Kawasaki disease(KD-MAS),and 17 cases of connective tissue disease(CTD-MAS).The clinical and laboratory data were collected before(pre-),at onset,and during full-blown stages of MAS.We compared the data among the SJIA-MAS,KD-MAS,and CTD-MAS subjects.Results 51.2%of patients developed MAS when the underlying disease was first diagnosed.In patients with SJIA,22.6%(12/53)were found to have hypotension before the onset of SJIA-MAS.These patients were also found to have significantly increased aspartate aminotransferase(AST)and lactate dehydrogenase(LDH),as well as decreased albumin(P<0.05),but no difference in alanine aminotransferase,ferdtin,and ratio of ferritin/erythrocyte sedimentation rate(ESR)at onset of MAS when compared to pre-MAS stages of the disease.In addition,ferritin and ratio of ferritin/ESR were significantly elevated in patients at full-blown stages of SJIA-MAS compared to pre-MAS stage.Significantly increased ferritin and ratio of ferritin/ESR were also observed in patients with SJIA compared to in KD and CTD.Receiver-operating characteristic analysis showed that 12,217.5μg/L of ferritin and 267.5 of ferritin/ESR ratio had sensitivity(80.0%and 90.5%)and specificity(88.2%and 86.7%),respectively,for predicting full-blown SJIA-MAS.The majority of the patients received corticosteroids(79/80),while biologic agents were used in 12.5%(10/80)of cases.Tocilizumab was the most commonly selected biologic agent.The overall mortality rate was 7.5%.Conclusions About half of MAS occurred when the underlying autoimmune diseases(SJIA,KD,and CTD)were first diagnosed.Hypotension could be an important manifestation before MAS diagnosis.Decreased albumin and increased AST,LDH,ferritin,and ratio of ferritin/ESR could predict the onset or full blown of MAS in patient with SJIA.

MicroRNA-125b regulates Th17/Treg cell differentiation and is associated with juvenile idiopathic arthritis

Background Juvenile idiopathic arthritis(JIA)is the most common rheumatic disease in childhood driven by aberrant pathways of T-cell activation.T helper 17(Th17)/regulatory T cell(Treg)imbalance plays critical roles in the pathogenesis of arthritis.MicroRNA-125b(miR-125b)was upregulated after the activation of the initial CD4^+T cells,and could regulate the differentiation of CD4^+T cells.However,the effects of miR-125b on Th17/Treg imbalance and differentiation of Th 17/Treg cells remain unknown.Methods In this study,we evaluated the expression of miR-125b in the peripheral blood mononuclear cells(PBMCs)of children with JIA,and the relationship of miR-125b with Th17/Treg imbalance.Then,we used lentivirus vector-mediated overexpression technology to investigate the regulatory function of miR-125b in CD4^+T cells or dendritic cell/CD4^+T co-culture system.Results Decreased miR-125b expression in PBMCs and CD4^+T cells of JIA patients was negatively correlated with the ratio of Th17/Treg cells.It also correlated negatively with retinoic acid receptor-related orphan receptorγt but positively with Forkhead box protein 3 at transcriptional levels.Furthermore,we found that miR-125b overexpression inhibited Th17 cell differentiation,whereas facilitated the differentiation of Treg cells.MiR-125b upregulation led to the decrease of Th 17-secreting cytokines but the increase of the Treg-secreting cytokines.Conclusions Our results demonstrate that miR-125b participated in regulating Thl7/Treg cell differentiation and imbalance in JIA patients.These findings provide novel insight into the critical role of miR-125b in the Th17/Treg imbalance of JIA,and raise the distinct possibility that miR-125b may prove to be a potential therapeutic target for JIA.