[Clinical Study of Intestinal Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation in Children].

OBJECTIVE: To observe the clinical characteristics, treatment and prognosis of intestinal acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children and futher evaluate the occurring risk factors. METHODS: The clinical data of 136 patients undergoing allo-HSCT in Wuhan Children's Hospital Affiliated to Tongji Medical College from August 2016 to August 2020 were retrospectively analyzed, clinical characteristics of children with intestinal aGVHD were observed. The risk factors of intestinal aGVHD were assessed by logistic regression while cumulative survival were analyzed by Kaplan-Meier method. RESULTS: Among 136 patients intestinal aGVHD occurred in 24 (17.6%) cases, with 4 cases of grade II, 20 cases of grade III-IV, and the median occurrence time was 28(10-63) days. The clinical manifestations were diarrhea with intermittent abdominal pain, 17 cases with nausea and vomiting, 11 cases with fresh bloody stool, and 8 cases with skin rash before intestinal aGVHD. The average time for treatment was 33(11-100) days. 18 cases received electronic colonoscopy and histopathology examination. 20 out of 24 cases achieved remission after treatment, and the total effective rate was 83.3%. Finally, 9 out of 24 cases died during the follow-up time. Survival analysis showed that the cumulative survival rate of patients with intestinal aGVHD (15/24, 62.5%) were significantly lower than those without intestinal aGVHD (101/112, 90.2%) (Log-rank test, P=0.001). Univariate analysis showed that recipient age, sex, primary disease, donor age, donor sex, donor-recipient blood type, conditioning regimen, prophylaxis of GVHD, dosage of ATG, engraft time of blood platelet and neutrophils, and number of MNC/CD34+ were not risk factors for intestinal aGVHD (P>0.05). Only the type of HSCT (χ2=16.020, P=0.001) and matched degree of HLA (χ2=15.502, P=0.001) had statistical significance with intestinal aGVHD (P<0.05). Multivariate analysis showed that only HLA-mismatched unrelated donor was the risk factor for intestinal aGVHD for children (P=0.014，OR=16，95%CI 1.735-147.543). CONCLUSION: Intestinal aGVHD is a risk factor for cumulative survial of patients who received allo-HSCT in children and HLA-mismatched unrelated donor is its independent risk factor.

[Infection in Children with Acute Myeloid Leukemia in the Intensive Chemotherapy Period].

OBJECTIVE: To investigate the clinical characteristics of infection in children with acute myeloid leukemia (AML) after high intensive chemotherapy， so as to provide reference for prevention and control of infection. METHODS: 56 children diagnosed as acute myeloid leukemia in our hospital from January 2016 to August 2019 were enrolled and retrospectively analyzed, the infection rate, pathogens of disease and common location of infection during the induction and consolidation period were analyzed. RESULTS: The total infection rate of the patients was 93.4%－96.4%, the average of serious infection rate was 16.0%(11.3%－19.6%), and the infection related mortality was 10.7%. Fever of unknown cause was the main reason of infection, while blood flow infections were the most common in severe infection, which were mainly caused by Gramnegative bacteria. The rate of fungal infection was 35.7% during chemotherapy. CONCLUSION: Children with AML shows a high incidence of infection in each stage of chemotherapy. The serious illness caused by blood flow infection and take antifungal drugs to reduce the occurrence of fungal infection in AML patients should be paid attention.

[Analysis of the Outcome and Prognostic Factors of Cyclosporine A in Children with Non-severe Aplastic Anemia].

OBJECTIVE: To summarize the long-term efficacy of cyclosporine (CsA) in the treatment of non-severe aplastic anemia (NSAA) in children, and explore the early significant indicators. METHODS: Data of 36 NSAA children in Department of Hematological Oncology, Wuhan Children's Hospital, Tongji Medical College of Huazhong University of Science and Technology from January 2013 to December 2017 were analyzed retrospectively. All the children received oral CsA immunosuppressive therapy, and CsA trough concentration was checked to maintain at the rage of 200-250 µg/L after 2 weeks. The evaluation time points were at 3, 6, 12, 18 and 24 months, and assessment items were peripheral white blood cell differential count and reticulocyte's percentage and count. RESULTS: The 36 NSAA cases were composed of 16 males and 20 females, whose median age was 5.46 (2.92-7.99) years old, and median follow-up time was 28.00 (10.00-38.25) months. After taking oral CsA for 24 months, the number of cumulative effective cases was 21. There were 4 cases of complete remission (CR), 17 cases of partial remission (PR), and 15 cases of non-remission (NR). The total effective rate was 58.33%, and median effect-acting time of CsA was 3.0 (0.5-10.0) months. Compared with ineffective group, neutrophil (NEU) and red blood cell (RBC) of effective group (CR+PR) began to increase significantly at the 3rd month, and hemoglobin (Hb), platelet (PLT) and white blood cell (WBC) increase significantly at the 6th month after oral CsA administration (P<0.05). Except for 2 cases who received component transfusion within 3-12 months after taking oral CsA for 3 months in effective group, the others did not need. CONCLUSION: The overall effective rate of oral CsA in children with NSAA was 58.33%. Stopping blood transfusion after the 3 months of treatment may be considered as a turning point for disease outcomes, and levels of NEU, RBC at the 3rd month and Hb, PLT, WBC at the 6th month as indicators for predicting disease prognosis.

[The Relationship between Plasma sST2/Reg3α Levels and Acute Graft-Versus-Host Disease in Children After Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To explore the relationship between plasma sST2/Reg3α levels and acute graft-versus-host disease (aGVHD) in children after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: The clinical data of 29 pediatric patients received allo-HSCT treatment in Department of Hematology and Oncology of Wuhan Children's Hospital from January 2019 to January 2020 were collected. Peripheral blood samples were collected at 14 and 28 day after allo-HSCT. The plasma concentrations of sST2 and Reg3α were detected by Luminex assay. RESULTS: Among 29 patients there were 15 males and 14 females with a median age of 53 (29-117) months. After allo-HSCT, 18 patients developed grade 0-I aGVHD; while 11 patients developed grade II-IV aGVHD. These included skin aGVHD in 6 cases, gastrointestinal aGVHD (GI-aGVHD) in 3 cases and gastrointestinal/skin aGVHD in 5 cases. Plasma sST2 level in II-IV aGVHD group showed significantly higher than that in 0-I aGVHD group at 28 days after allo-HSCT [101.81 (73.94-150.77) ng/ml vs 48.97 (28.82-56.69) ng/ml, P=0.021]. Also, the plasma sST2 level was significantly higher in GI-aGVHD group than that in no-aGVHD group at 28 days after allo-HSCT [118.74 (87.00-243.36) ng/ml vs 48.97 (23.55-61.40) ng/ml, P=0.004]. Plasma sST2 level ≥65.34 ng/ml at 28 days after allo-HSCT showed a sensitivity of 85.7% and a specificity of 87.5% in predicting II-IV aGVHD. And the patients with a plasma sST2 level ≥65.34 ng/ml showed a significantly higher incidence of II-IV aGVHD than those with plasma sST2 level of < 65.34 ng/ml after allo-HSCT (P=0.021). There was no significant difference in plasma Reg3α level between the patients with II-IV aGVHD and the non-aGVHD ones. CONCLUSION: The increasing plasma sST2 level after allo-HSCT in children indicates the development of II-IV aGVHD, so sST2 is promising as a biomarker for predicting II-IV aGVHD.

Population Pharmacokinetics and Pharmacodynamics of Norvancomycin in Children With Malignant Hematological Disease.

Knowledge of pharmacokinetic (PK) behavior of norvancomycin (NVCM) in pediatric patients is lacking, which leads to empirical therapy in clinical practice. This study developed a population PK model of children aged 0-15 years; 112 opportunistic samples in total from 90 children were analyzed. The stability and prediction of the final model were evaluated by goodness-of-fit plots, nonparametric bootstrap, visual predictive check, and normalized prediction distribution errors. The PKs of NVCM in children was described by a 2-compartment model with first-order elimination along with body weight and estimated glomerular filtration rate as significant covariates on clearance. The population typical values of the PK parameters were as follows: clearance 0.12 L/kg/h, central compartment distribution volume 0.17 L/kg, peripheral compartment distribution volume 0.38 L/kg, and intercompartmental clearance 0.35 L/kg/h. Logistic analysis showed that the ratio of area under the concentration-time curve over 24 hours (AUC0-24 ) to minimum inhibitory concentration (MIC) had the strongest correlation with clinical efficacy, and at least 80% clinical efficiency could be achieved when AUC0-24 /MIC ≥ 221.06 was defined as the target. Monte Carlo simulation results suggested that a higher dose was required for this pediatric population in order to reach the target. The dosing regimen was optimized based on the final model. A population PK model of NVCM was first characterized in children with hematologic malignancy, and an evidence-based approach for NVCM dosage individualization was provided.

Population Pharmacokinetics of Caspofungin and Dosing Optimization in Children With Allogeneic Hematopoietic Stem Cell Transplantation.

Caspofungin is the first echinocandin antifungal agent that licented for pediatric use in invasive candidiasis and aspergillosis. In this study, we evaluated the population pharmacokinetics of caspofungin and investigate appropriate dosing optimization against Candida spp. in children with allogeneic hematopoietic stem cell transplantation (allo-HSCT) in order to improve therapeutic efficacy. All participants received a recommended caspofungin 70 mg/m2 loading dose followed by 50 mg/m2 maintenance dose. A one-compartment model with first-order elimination was best fitted the data from 48 pediatric patients. Body surface area and aspartate aminotransferase had significant influence on caspofungin clearance from covariate analysis. Our results reviewed that dose adjustment is not necessary in patients with mild liver dysfunction. Monte Carlo simulations were performed using pharmacokinetic data from our study to evaluate the probability of target attainment (PTA) of caspofungin regimen in terms of AUC24/MIC targets against Candida spp. The results of simulations predicted that a caspofungin 70 mg/m2 at first dose, 50 mg/m2 of daily dose may have a high probability of successful outcome against C. albicans and C. glabrata whilst 60 mg/m2 maintenance dose was required for fungistatic target against C. parapsilosis but may be not sufficient to achieve optimal fungicidal activity. Caspofungin standard regimen had high probability of successful outcome against C. albicans (MIC ⩽ 0.25 mg/L) and C. glabrata (MIC ⩽ 0.5 mg/L) but insufficient for C. parapsilosis with MIC > 0.25 mg/L. That may provide an evidence based support to caspofungin individualized administration and decrease the risk of therapeutic failure in allo-HSCT pediatric patients.

[Enhancement effects of hypoxia on invasion and metastasis of K562 cells].

OBJECTIVE: To study the potential effect of hypoxia on invasion and metastasis of leukemia cell line K562. METHODS: K562 cells were cultured with the conventional method in vitro and treated with 1%, 3% and 5% oxygen for 24 hrs. The normoxic cultured K562 cells were used as the control group. Cell adhesion assay, cell migration assay and cell invasion assay were used to detect the adhesion, migration and invasion abilities of K562 cells. RT-PCR was used to measure the mRNA expression of HIF-1alpha, VEGF, MMP-2 and MMP-9. The protein level of HIF-1alpha was measured by Western blot. RESULTS: Compared with the control group, the 3% and 5% oxygen treatment groups significantly increased the adhesion, migration and invasion abilities of K562 cells (p<0.05 or <0.01), and up-regulated the protein level of HIF-1alpha and the mRNA levels of HIF-1alpha,VEGF, MMP-9 and MMP-2 (p<0.05 or 0.01). However, there were no significant differences in the above indexes between the 1% oxygen treatment and the control groups. CONCLUSIONS: Moderate hypoxia can enhance the abilities of invasion and metastasis of K562 cells, probably by an up-regulation of HIF-1alpha level and VEGF, MMP-2 and MMP-9 mRNA expression.