Enhanced Autophagy Suppresses Proplatelet Formation in Pediatric Immune Thrombocytopenia / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of enhanced autophagy in megakaryocyte to proplatelet formation in children with immune thrombocytopenia(ITP).@*METHODS@#Giemsa staining and immunofluorescence staining were used to observe megakaryocyte morphology and proplatelet formation, Western blot was used to determine the expression of cytoskeleton protein and autophagy related protein. Autophagr regulation drugs Rap or 3-MA was used to regulate autophagy of megakaryocytes.@*RESULTS@#Some vacuole-like structures was found in ITP megakaryocytes of the children, the expression of LC3II/I (ITP 1.32±0.18； Ctrl 0.49±0.16，P<0.05) and Atg5-Atg12 (ITP 0.69±0.17； Ctrl 0.12±0.08，P<0.05) was significantly higher in ITP children as compared with those in control group. The immu- nofluorescence staining showed that the cytoskeleton arrangement in megakaryocytes of ITP children was abnormal, and the phosphorylation of myosin light chain was also increased(ITP 0.74±0.09, Ctrl 0.05±0.02，P<0.05). In vitro, inducer or inhibitor of autophagy could regulate the production of proplatelet and the expression of cell cycle related protein, including CyclinD1（Veh 1.08±0.12; Rap 0.46±0.04; Rap+3-MA 0.70±0.03）, CyclinD2（Veh 0.47±0.04; Rap 0.27±0.04; Rap+3-MA 0.41±0.03）, P21（Veh 0.15±0.01; Rap 0.04±0.01; Rap+3-MA 0.05±0.01）.@*CONCLUSION@#Enhanced autophagy is the key factor of poor proplatelet formation in megakaryocytes of ITP children.

Clinical significance of dynamic monitoring the minimal residual disease in childhood B-lineage acute lymphoblastic leukemia by multiparameter flow cytometry / 中国实验血液学杂志

This study was aimed to explore the clinical significance of monitoring level of minimal residual disease (MRD) at different time point in B-lineage childhood acute lymphoblastic leukemia (B-ALL). Two hundred and six children with B-ALL were enrolled in this study from Augest 2008 to September 2011 in our hospital. MRD levels were detected by flow cytometry at day 15, 33 and week 12 after initial chemotherapy. The event-free survival (EFS) for patients based on MRD levels measured at different stages of chemotherapy were compared by Kaplan Meier analyses. The results showed that out of 206 cases 196 cases achieved complete remission (CR) after induction therapy (CR rate 95.1%), the 1- and 3-year EFS rate were (92.7 ± 1.8)% and (78.7 ± 3.7)%, respectively, and the 3-year EFS rate was (85.6 ± 4.9)% in standard risk group, (82.1 ± 5.8)% in intermediate risk group and (58.1 ± 9.2)% in high risk group, there was significant statistical difference between above mentioned 3 groups (P < 0.001). The MRD analysis at different time points showed that the higher the MRD level, the lower the 3-year EFS rate of children with ALL, in which the 3-year EFS rate of MRD ≥ 10(-2) at day 15, MRD ≥ 10(-3) at day 33 and MRD ≥ 10(-3) at week 12 were significantly lower. The MRD ≥ 10(-3) at week 12 was proven to be an independent predictor by multivariate Cox proportional-hazards regression model. The 3-year EFS rate for patients with MRD < 10(-3) and MRD ≥ 10(-3) at week 12 were (86.3 ± 4.1)% vs (55.8 ± 9.1)% (P < 0.05); 8 relapsed among 98 cases with negative MRD (MRD < 10(-4)) at day 33, 19 relapsed among 108 cases with positive MRD at day 33 between the two groups for recurrence rate has significant difference (P < 0.05). It is concluded that dynamically monitoring MRD by multi-parameter flow cytometry can precisely evaluate treatment response, judge treatment outcome and predict relapse in childhood B-ALL. The MRD 10(-2) at day 15, MRD 10(-3) at day 33 and MRD 10(-3) at week 12 should be considered as the best cut-off. MRD ≥ 10(-3) at week 12 was proven to be an independent factor of poor prognosis.

Epidemiological study on respiratory syncytial virus and its bronchopneumonia among children in Suzhou / 中华预防医学杂志

<p><b>OBJECTIVE</b>To probe the epidemiological trend of respiratory syncytial virus (RSV) and cellular immunological change of RSV bronchopneumonia among children in Suzhou in the past five years.</p><p><b>METHODS</b>10,205 children with acute respiratory tract infection from January 2001 to December 2005 were enrolled into the study. Nasopharyngeal aspirates were obtained from the respiratory tract by aseptic vacuum aspiration. Direct immuno-fluorescence assay was employed to detect seven kinds of virus antigens including RSV antigen. CD3, CD4, CD8, CD19, CD16 and CD56 in peripheral blood mononuclear cells of 30 patients with RSV bronchopneumonia (1.5-24.0 months old group) were analyzed by flow cytometry analysis, and 15 normal infants (1.5-24.0 months old group) were enrolled as control group.</p><p><b>RESULTS</b>The annual positive rate of RSV was 24.94%, 25.83%, 24.05%, 25.39% and 27.30% respectively from 2001 to 2005. It also found that the peak season for RSV infection was spring or winter (January to March or November to December). The positive rate of RSV was significantly higher in 1-12 months old group than that in > 12 months old group (chi2 = 97.320, P < 0.01), as well as the groups between 1-12 months old (chi2 = 7.804, P < 0.05, the highest positive rate was occurred at 3-6 months old group). The positive rate of RSV was significantly higher in boys than that in girls (chi2 = 9.693, P < 0.01). The percentages of CD3+, CD4+, CD8+ and NK (CD16 + 56)+ cells were significantly lower in RSV bronchopneumonia than those in control group (t = 3.199, P < 0.01; t = 2.215, P < 0.05; t = 2.619, P < 0.05 and t = 5.240, P < 0.01, respectively). While the percentage of CD19+ cells was significantly elevated in RSV bronchopneumonia than that in control group (t = 2.875, P < 0.01).</p><p><b>CONCLUSION</b>RSV infection is of obvious seasonal changes. The younger the patient, the higher positive rates of RSV infection is, while and the cellular immunity function is lower. The effective measures for preventing RSV infection are important, especially for the infants. Further investigation is necessary to understand the causes of the variations for RSV infections between boys and girls.</p>