Objective:To study the changes of plasma receptor interacting protein 3 (RIP3) levels in neonatal late-onset sepsis (LOS) and to determine its clinical value.Methods:From October 2019 to April 2021, plasma samples and clinical data of LOS infants admitted to our hospital were prospectively studied. Infants with similar gestational ages admitted for non-infectious diseases were assigned into the control group. Enzyme-linked immunoassay was used to determine plasma RIP3 levels. The clinical value of plasma RIP3 in the diagnosis and treatment of neonatal LOS were analyzed.Results:A total of 152 cases (76 in the LOS group and 76 in the control group) were included in the study. No significant differences existed in the baseline data between the two groups. A total of 226 plasma samples were collected (76 samples from the LOS group before treatment, 74 samples after treatment and 76 samples from the control group). The plasma RIP3 level of LOS group before treatment (19.9±6.3 ng/ml) was significantly higher than the control group (11.4±3.5 ng/ml) and the after treatment group (11.9±3.5 ng/ml) ( P<0.05). The plasma RIP3 level had good diagnostic value for neonatal LOS (AUC=0.884). With cut-off value of 15.5 ng/ml, the plasma RIP3 showed the best diagnostic efficacy (Youden index 0.658, sensitivity 72.4%, specificity 93.4%, positive likelihood ratio 11.0, negative likelihood ratio 0.3). Conclusions:Plasma RIP3 level is closely related with neonatal LOS and may be used for the early diagnosis and therapeutic evaluation of neonatal LOS.

Objective:To summarize the clinical characteristics of neonatal late-onset sepsis (LOS) caused by Leclercia adecarboxylata, and provide evidence for its diagnosis and treatment. Methods:We report a case of Leclercia adecarboxylata induced LOS in a male preterm neonate diagnosed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) at the Affiliated Suzhou Hospital of Nanjing Medical University. Relavant literature was retrieved from Wanfang, VIP, CNKI, and PubMed databases up to April 2021, using terms including "neonate" "sepsis" and " Leclercia adecarboxylata". Results:The patient presented with dyspnea immediately after birth with gestational age of 34 +3 weeks and birth weight of 2 050 g. After admission at 14 min after birth, he was incubated at temperature of 33-35 ℃ and humidity of 50%-60% and received active treatment, consisting of nasal continuous positive airway pressure, tracheal intubation, intratracheal injection of pulmonary surfactant, invasive mechanical ventilation, and anti-infective treatment with piperacillin, cefoperazone/sulbactam, and meropenem. However, the patient developed LOS on day 11 of life and eventually died of disseminated intravascular coagulation and multiple organs failure despite volume expansion, anti-infective therapy, and respiratory support. The blood culture was positive for Gram-negative rod and confirmed as a multi-drug resistant strain of Leclercia adecarboxylata. Two cases of LOS caused by sensitive strain of Leclercia adecarboxylata in premature female infants were retrieved in the literature with atypical symptoms, of whom one was successfully treated and one died after active treatment. Conclusions:Leclercia adecarboxylata infection alone can lead to LOS in preterm infants without typical manifestations. MALDI-TOF MS is helpful for the diagnosis and rational application of antibiotics.

Objective:To investigate the clinical features of patients with Langerhans cell histiocytosis (LCH), and analyze the association between BRAF V600E mutation status and clinical features. Methods:A retrospective analysis was carried out for the clinical data of 60 patients with LCH at the Department of Pediatric Oncology, Sun Yat-sen Memorial Hospital between April 2013 and December 2019.Among them, 39 patients undertook BRAF V600E mutation testing, which in paraffin-embedded tissue samples were detected by quantitative real-time PCR (qRT-PCR), and in peripheral blood and/or bone marrow were tested by high-throughput sequencing, for analyzing the correlation between BRAF V600E mutation and clinical characteristics of LCH. Results:(1)Clinical characteristics: the age of 60 LCH patients was (4.08±0.45) years, with 43 male cases and 17 female cases.Patients at young age (≤2 years) and with risk organ (RO+ ) and central nervous system (CNS) risk lesions involvement were concentrated in the multisystem involvement (MS) group ( P<0.05). (2)Therapeutic response after induction therapy: the response to induction therapy was achieved in 28 of 60 treated patients (41.7%) and 32 (53.3%) did not.After excluding stratification factors of treatment regimen, MS ( OR=6.855, 95% CI: 2.077-22.622, P=0.002) and the age≤2 years ( OR=4.944; 95% CI: 1.601-15.275; P=0.005) were risk factors in poor chemotherapy response.RO+ ( OR=8.250, 95% CI: 1.617-42.090, P=0.005) was a significant risk factor for a poor chemotherapy response in JLSG-02 treatment group.Differently, RO+ had no dramatic effect on chemotherapy response in CCHG-LCH-2019 treatment group.(3) BRAF V600E mutation: 39 patients were determined BRAF V600E status, with the positive rate of BRAF V600E mutation in paraffin-embedded tissue samples reaching 70.3%(26 cases). BRAF V600E mutation was not associated with early treatment response, age, sex, MS and RO+ ( P>0.05). However, the positive rate of BRAF V600E in children with MS and CNS risk lesions was higher than the controls, with 76.0% (19 cases) vs.57.1% (8 cases) and 74.1% (20 cases) vs.58.3% (7 cases), respectively.Totally, 3 of 8 cases were positive in bone marrow, with 2 cases of MS, and 1 case of multiple bone invasions, and 1 of 5 cases was positive in peripheral blood, with liver and spleen being involved. Conclusions:LCH patients with age≤2 years, MS and RO+ exhibited a poor response to initial treatment, required for more aggressive treatment strategy.Lesion with activating BRAF V600E mutations suggests that LCH is a clonal disorder.There may be great variability between BRAF V600E mutations and MS as well as CNS risk lesions.In the mutation dataset, part of patients had positive BRAF V600E mutations in bone marrow/peripheral blood.This might suggest a different pathogenesis in such patients, has a certain clinical sense in some aspect.

Objective To investigate the effect of different concentrations of Echinococcus multilocularis secretion antigen (Em-sAg) on the phenotype and function of mouse bone marrow-derived dendritic cells (BMDCs) induced by lipopolysaccharide (LPS). Methods The bone marrow precursor cells isolated from the mouse bone marrow cavity were stimulated by mouse recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) to form BMDCs, and then cell morphology was observed under an inverted microscope. After the purity of BMDCs was identified by flow cytometry, BMDCs were divided into control group, positive control group (LPS 1 μg/ml), LPS+3 mg/ml Em-sAg group, LPS+1.5 mg/ml Em-sAg group, LPS+0.75 mg/ml Em-sAg group, and LPS+0.375 mg/ml Em-sAg group. Flow cytometry was used to measure the expression of BMDC surface molecules (CD80, CD86, and MHC-Ⅱ molecules) in each group, and ELISA was used to measure the expression level of the cytokine IL-12p70. A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the least significant difference t -test was used for further comparison between two groups. Results Observation under an inverted microscope showed that after 8-10 days of culture, the cells had burr-like protrusions and were in a state of complete suspension. Flow cytometry showed that the positive rate of CD11c was above 70% and most of the cultured cells were identified as BMDCs based on this. Flow cytometry further showed that compared with the control group, the LPS group had significant increases in the cell molecules CD80, CD86, and MHC-Ⅱ on surface (all P < 0.05); compared with the LPS group, the LPS+3 mg/ml Em-sAg group, the LPS+1.5 mg/ml Em-sAg group, the LPS+0.75 mg/ml Em-sAg group, and the LPS+0.375 mg/ml Em-sAg group had a significant reduction in CD80 ( F =34.870, P < 0.001), while there were no significant reductions in CD86 and MHC-Ⅱ( P > 0.05). ELISA showed that there was a significant difference in the level of IL-12 p70 between groups ( F =73.140, P < 0.05); compared with the control group, the LPS group had a significant increase in the expression level of IL-12p70 after stimulation ( P < 0.05); compared with the positive control group, the LPS+3 mg/ml Em-sAg group, the LPS+1.5 mg/ml Em-sAg group, the LPS+0.75 mg/ml Em-sAg group, and the LPS+0.375 mg/ml Em-sAg group had a significant reduction in the expression level of IL-12p70 ( P < 0.05), and the degree of reduction in the pro-inflammatory factor IL-12p70 increased with the increase in the concentration of Em-sAg. Conclusion Different concentrations of Em-sAg can inhibit LPS-induced maturity of BMDCs and the expression of the pro-inflammatory cytokine IL-12p70.