Objective:To analyze the clinical characteristics of children with systemic lupus erythematosus (SLE) combined with thrombotic microangiopathy (TMA), and clarify the clinical outcomes and related risk factors of pediatric patients through their treatment and follow-up.Methods:This was a single-center retrospective case-control study. Children diagnosed with SLE combined with TMA between January 2017 and January 2023 at Beijing Children′s Hospital, Capital Medical University, were selected as the TMA group, and SLE children without TMA were selected as the control group.According to the prognosis, children in the TMA group were further divided into the good prognosis group and the poor prognosis group.The data of the children were collected, including age, gender, SLE disease activity, clinical presentations at the time of diagnosis and at the time of thrombosis, laboratory examinations, treatment strategies, prognosis, and follow-up results.The chi-square test and Z-test were used for comparison of count data.The t-test was used for comparison of metrological pairing data.The Fisher′s exact test was used to compare the differences between the 2 groups in categorical variables.The univariate Logistic regression was used to analyze the risk factors of poor prognosis. Results:There were 29 cases in the TMA group, and the incidence of TMA accounted for 2.53% of SLE patients; 33 cases were in the control group.The age at diagnosis of TMA was 13 years and 5 months (ranging from 9 years, 1 month and 5 days to 17 years and 4 months).The common clinical manifestations in order of prevalence were renal involvement (28 cases, 96.55%), hematologic involvement (26 cases, 89.66%), serous effusion (17 cases, 58.62%), rash (13 cases, 44.82%), and neurologic involvement (12 cases, 41.38%).Pleurisy or pericarditis, renal involvement and neurological involvement occurred more often in the TMA group than in the control group (17 cases vs.3 cases, 28 cases vs.10 cases, 12 cases vs.3 cases), and the TMA group showed less facial rash and arthritis than the control group (13 cases vs.25 cases, 4 cases vs.17 cases), and the differences were statistically significant (all P<0.05).The Systemic Lupus Erythematosus Disease Activity Index score in the TMA group [(24.14±9.42) scores] was significantly higher than that in the control group [(10.18±9.42) scores], and the difference was statistically significant ( t=3.233, P<0.05).The hemoglobin level, platelet count, and complement C3 level of the children in the TMA group were significantly lower than those in the control group, whereas the double stranded DNA antibody, lactate dehydrogenase, D-dimer, urea, creatinine, ferritin level, and urine protein quantitation were significantly higher than those in the control group, and the differences were statistically significant (all P<0.05).In the TMA group, 5 cases had decreased ADAMTS13 activity, and 5 cases had significantly increased complement C5b9.A total of 15 cases (51.72%) in the TMA group underwent renal biopsy, and 13 of them had combined renal TMA.In the TMA group, 28 patients (96.6%) received hormone therapy, 17 patients received plasma exchange, and 12 patients were treated with immunosuppressants and biologics; 19 patients (65.5%) improved, and 10 patients (34.5%) gave up the treatment due to deterioration of the disease.The urea level and peripheral blood fragmented erythrocyte rate in the good prognosis group were significantly lower than those in the poor prognosis group [(13.18±4.39) mmol/L vs.(21.16±10.14) mmol/L, t=2.975, P=0.006; 8/17 (47.06%) vs.7/7 (100%), χ2=5.929, P=0.015].The univariate Logistic regression analysis showed that the fragmented erythrocyte, ADAMTS13 activity and urea were the independent risk factors for poor prognosis (all P<0.05). Conclusions:SLE patients with moderate-to-severe disease activity, especially children with hemolytic anemia, thrombocytopenia, and renal dysfunction as prominent manifestations, should be alert to the risk of TMA.Early diagnosis and treatment are crucial.

  Objective  To study the demographic and clinical characteristics, correlation of genotype and phenotype and treatment of Blau syndrome to facilitate early diagnosis and timely treatment of Blau syndrome.  Methods  Seventy-two patients with Blau syndrome from 11 centers from May 2006 to April 2022 were retrospectively analyzed, and their general information, clinical data, laboratory examination and treatment medication were collected.  Results  The distribution of patients with Blau syndrome was uniform in geographical north and south of China, and there was no obvious gender bias. The mean age of onset was (14.30±12.81) months, and the age of diagnosis was (55.18±36.22) months. 35% of patients with Blau syndrome happened before 1 year old, and all patients developed before 5 years old. 87.50% (63/72) had granulomatous arthritis, 65.28% (47/72) had rash, 36.11% (26/72) had ocular involvement, 27.78% (20/72) had fever, and 15.28% (11/72) had pulmonary involvement. Arthritic manifestations of Blau syndrome were most at risk, followed by rash, ocular involvement, and fever.The first 25 months of the disease, the risk of developing a rash was the greatest. The risk of developing arthritis was the greatest between 25 months and 84 months. The main mutations were p.R334Q and p.R334W, and patients with p.R334Q mutation had relatively high incidence of fever (35.71%[5/14] vs. 14.29%[1/7], P=0.43) and ocular involvement (42.86%[6/14]vs. 28.57%[2/7], P=0.51). There was a relatively high incidence of rash (85.71%[6/7] vs. 64.29%[9/14], P=0.59) in patients with the p.R334W mutation. Forty-five patients(62.50%)were treated with a combina-tion of glucocorticoid and methotrexate. Twenty-two patients were treated with tumor necrosis factor antagonist in addition to glucocorticoid and methotrexate.  Conclusions  The risk of different clinical manifestations of Blau syndrome from high to low was arthritis, followed by rash, ocular involvement and fever. The main treatment was glucocorticoid combined with methotrexate, to which biological agents could be added.