[A multicenter epidemiological study of acute bacterial meningitis in children].

Objective: To analyze the clinical epidemiological characteristics including composition of pathogens , clinical characteristics, and disease prognosis acute bacterial meningitis (ABM) in Chinese children. Methods: A retrospective analysis was performed on the clinical and laboratory data of 1 610 children <15 years of age with ABM in 33 tertiary hospitals in China from January 2019 to December 2020. Patients were divided into different groups according to age,<28 days group, 28 days to <3 months group, 3 months to <1 year group, 1-<5 years of age group, 5-<15 years of age group; etiology confirmed group and clinically diagnosed group according to etiology diagnosis. Non-numeric variables were analyzed with the Chi-square test or Fisher's exact test, while non-normal distrituction numeric variables were compared with nonparametric test. Results: Among 1 610 children with ABM, 955 were male and 650 were female (5 cases were not provided with gender information), and the age of onset was 1.5 (0.5, 5.5) months. There were 588 cases age from <28 days, 462 cases age from 28 days to <3 months, 302 cases age from 3 months to <1 year of age group, 156 cases in the 1-<5 years of age and 101 cases in the 5-<15 years of age. The detection rates were 38.8% (95/245) and 31.5% (70/222) of Escherichia coli and 27.8% (68/245) and 35.1% (78/222) of Streptococcus agalactiae in infants younger than 28 days of age and 28 days to 3 months of age; the detection rates of Streptococcus pneumonia, Escherichia coli, and Streptococcus agalactiae were 34.3% (61/178), 14.0% (25/178) and 13.5% (24/178) in the 3 months of age to <1 year of age group; the dominant pathogens were Streptococcus pneumoniae and the detection rate were 67.9% (74/109) and 44.4% (16/36) in the 1-<5 years of age and 5-<15 years of age . There were 9.7% (19/195) strains of Escherichia coli producing ultra-broad-spectrum ß-lactamases. The positive rates of cerebrospinal fluid (CSF) culture and blood culture were 32.2% (515/1 598) and 25.0% (400/1 598), while 38.2% (126/330)and 25.3% (21/83) in CSF metagenomics next generation sequencing and Streptococcus pneumoniae antigen detection. There were 4.3% (32/790) cases of which CSF white blood cell counts were normal in etiology confirmed group. Among 1 610 children with ABM, main intracranial imaging complications were subdural effusion and (or) empyema in 349 cases (21.7%), hydrocephalus in 233 cases (14.5%), brain abscess in 178 cases (11.1%), and other cerebrovascular diseases, including encephalomalacia, cerebral infarction, and encephalatrophy, in 174 cases (10.8%). Among the 166 cases (10.3%) with unfavorable outcome, 32 cases (2.0%) died among whom 24 cases died before 1 year of age, and 37 cases (2.3%) had recurrence among whom 25 cases had recurrence within 3 weeks. The incidences of subdural effusion and (or) empyema, brain abscess and ependymitis in the etiology confirmed group were significantly higher than those in the clinically diagnosed group (26.2% (207/790) vs. 17.3% (142/820), 13.0% (103/790) vs. 9.1% (75/820), 4.6% (36/790) vs. 2.7% (22/820), χ2=18.71, 6.20, 4.07, all P<0.05), but there was no significant difference in the unfavorable outcomes, mortility, and recurrence between these 2 groups (all P>0.05). Conclusions: The onset age of ABM in children is usually within 1 year of age, especially <3 months. The common pathogens in infants <3 months of age are Escherichia coli and Streptococcus agalactiae, and the dominant pathogen in infant ≥3 months is Streptococcus pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. ABM should not be excluded even if CSF white blood cell counts is within normal range. Standardized bacteriological examination should be paid more attention to increase the pathogenic detection rate. Non-culture CSF detection methods may facilitate the pathogenic diagnosis.

[Clinical manifestations of Langerhans cell histiocytosis with multisystem involvement in 53 children].

Objective: To analyze the clinical characteristics and long-term outcome of Langerhans cell histiocytosis with multisystem involvement (MS-LCH) in children, and to evaluate the efficacy of modified DAL-HX83/90 protocol. Methods: This retrospective study included 53 patients with MS-LCH admitted to the Department of Pediatric Hematology and Oncology, First Affiliated Hospital of Zhengzhou University from January 2011 to May 2019. Modified DAL-HX83/90 protocol was used in all patients as an initial treatment. The patients were divided into the group with (RO+) or without (RO-) risk organ involvement. The RO+group was further divided into two groups, as RO+Ⅰ group (lung involvement only) and RO+Ⅱ group (extra-pulmonary, with or without lung involvement). The clinical characteristics and the long-term outcome were summarized. Event-free survival (EFS) and overall survival (OS) curves were analyzed with Kaplan-Meier method. Univariate and multivariate analysis of prognostic factors including age, sex, risk organ involvement and response to 6-week induction were analyzed with Log-Rank test and Cox proportional hazards models. Results: Among the 53 children with MS-LCH, 34 were male and 19 were female. The age of onset was 21 months (3 months-13 years). There 22 were in RO+group, with 12 in RO+Ⅰ group and 10 in RO+Ⅱ group, and 31 in RO-group. The follow-up period was 51 (12-144) months. The overall response rate of 6-week induction was 89% (47/53), and the recurrence rate was 30% (16/53). The 5-year EFS and OS were (67±6) % and (83±5) %, respectively. Univariate analysis showed that the 5-year EFS and OS of patients who responded well to 6-week induction chemotherapy were significantly higher than those who had no response ((76±6) % vs. 0, (88±4) % vs. (41±22) %, χ2 = 34.743, 10.608, both P<0.05). The 5-year EFS and OS of RO-group were significantly higher than that of RO+group ((80±7) % vs. (49±10) %, (93±4) % vs. (70±10) %, χ2=6.022, 4.793, both P<0.05). And the 5-year EFS of RO+Ⅰ group was significantly higher than that of RO+Ⅱ group ((83±10) % vs. (10±9) %, χ2=9.501, P=0.002). While age and sex were not significantly associated with 5-year EFS and OS (all P>0.05). Cox proportional hazard regression model showed that response to 6-week induction chemotherapy was the independent risk factor for EFS (HR=13.114, 95%CI 3.759-45.742, P<0.01) and OS (HR=7.748, 95%CI 1.542-38.920, P=0.013). Conclusions: Most of the children without risk organ involvement treated with modified DAL-HX83/90 protocol could achieve long-term survival. However, the children involved liver, spleen, or hematopoietic system had a high risk of disease progression and recurrence.

Potential role and mechanism for high mobility group box1 in childhood chronic immune thrombocytopenia.

OBJECTIVE: High mobility group box1(HMGB1) can be used as PAMP or alarmins to stimulate the innate immune system; however, previous research on immune thrombocytopenic purpura (ITP) mainly focused on its adaptive immunity. The study aimed to determine whether HMGB1 is associated with chronic ITP (cITP) during childhood and investigate its role in innate immunity in childhood cITP. PATIENTS AND METHODS: We recruited 80 patients to measure the expression of HMGB1, IL-17, and IL-10; 55 patients were recruited to measure the expression of TLR2 and TLR4 in monocyte and CD1c+dendritic cells, and 30 volunteers were included as controls. We focused on the expression of the NLRP3 inflammasome during childhood cITP. Furthermore, the impact of HMGB1 on the NLRP3 inflammasome was explored. RESULTS: The expressions of HMGB1 and IL-17 increased in children with cITP, while that of IL-10 decreased; HMGB1 was correlated with the expression of IL-17 and IL-10. The expression of TLR2 in CD14++CD16+, CD14+CD16++ monocytes increased significantly in comparison with the controls; the contrary was observed regarding TLR4. The expression of NLRP3, IL-1ß, and IL-18 was significantly higher in CD14 and CD1c, respectively. As the concentration of HMGB1 increased, the expression of NLRP3, IL-1ß, and IL-18 increased in different degrees. CONCLUSIONS: HMGB1 could be used as an early warning alarm for childhood cITP and is involved in developing cITP. HMGB1 could affect the incidence and development of chronic childhood ITP via the NLRP3, TLR2/TLR4 pathways.

Effect of small interfering RNA targeting wild-type FLT3 in acute myeloid leukaemia cells in vitro and in vivo.

This study investigated the effect of using small interfering RNA (siRNA) to silence the wild-type FMS-like tyrosine kinase 3 (FLT3) gene in acute myeloid leukaemia (AML) cells, in vitro and in vivo. FLT3 siRNA was introduced into the human AML cell line, THP1, and into a THP1 xenograft tumour model in BALB/c nude mice. FLT3 siRNA effectively reduced both the mRNA and the protein levels of FLT3, arrested cells in G(0)/G(1) phase, inhibited THP1 cell proliferation and increased apoptosis. Intraperitoneal injection of FLT3 siRNA suppressed tumour growth in BALB/c nude mice. FLT3 siRNA treatment also reduced cyclin D1 and Bcl-2 protein levels, and increased the nuclear level of silencing mediator for retinoic acid and thyroid hormone receptors protein both in vitro and in vivo. These data suggest that FLT3 siRNA is a strong inhibitor of FLT3 expression in vitro and in vivo, and may provide a new therapeutic target for AML.