Gut microbiota trajectory in ß-thalassemia major children who underwent allogeneic hematopoietic stem cell transplantation.

BACKGROUND: The gut microbiota of patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) changes, leading to complications such as acute graft-versus-host disease (GVHD). This study aimed to evaluate the human microbiota composition before and after HSCT in ß-thalassemia major (ß-TM) children. METHOD: Twenty-two ß-TM children who received allo-HSCT between December 2018 and March 2020 were enrolled. They were followed up for more than 100 days after HSCT, and their gut microbiota information and disease data were recorded at five-time points. RESULTS: The dominant bacteria were Bacteroidetes and Firmicutes at the phylum level and Lachnospiraceae at the family level before and after HSCT. In the differential analysis, Ruminococcaceae constantly decreased after HSCT. Besides, Rothia mucilaginosa was the most abundant 2 months after HSCT compared to before it. Additionally, GVHD patients presented decreased levels of Bacteroidetes compared to those without GVHD. Moreover, Blautia levels significantly decreased in critically ill GVHD patients. CONCLUSION: The gut microbiota of the 22 ß-TM children showed a clear trend of destruction and reconstruction within 100 days after HSCT. The extra-oral infections and inflammations of Rothia mucilaginosa, a Gram-positive bacterium of the normal oropharyngeal tract microbiota, might play an important role in the recovery process of HSCT. Finally, decreased Bacteroidetes levels were associated with GVHD onset.

[Bmi-1 as A Molecular Marker for Prognosis of Pediatric ALL].

OBJECTIVE: To study whether the Bmi-1 gene can be a biomarker for analysis of clinical risk stratification and prognosis of ALL patients. METHODS: The expression level of Bmi-1 gene in bone marrow samples from 127 cases of newly diagnosed ALL was detected by qRT-PCR, at the same time the expression level of Bmi-1 protein in bone marrow samples from above-mentioned cases was detected by Western blot. The collected samples were divided into 3 groups: high, intermediate and low risk according to clinical risk stratfication, the relationship between Bmi-1 expression and risk grade of ALL patients was analyzed; at the same time the collected samples were divided into 2 groups: prednisone good response (PGR) and prednisone poor respouse (PPR) according to the sensitivity of prednison test, and the sensitivily to prednisone in 2 groups was compared; moreover, the collected samples were divided into 2 groups: high level and low level according to median of Bmi-1 level, and the relation of Bmi-1 level with prognosis of patients was analyzed by using the Kaplan-Meier method. RESULTS: The expression level of Bmi-1 in low risk group was lowest, while that in high risk group was highest, however that in intermediat risk group was between the low and high risk groups, statistical analysis showed significant difference (P＜0.05). The expression level of Bmi-1 in PPR group was significantly higher than that in PGR group (P＜0.001). The Kaplan-Meier analysis showed that the RFS rate in Bmi-1 high expression group was significantly lower than that in Bmi-1 low expression group (73.0% vs 90.6%) (P＜0.001). CONCLUSION: The Bmi-1 can be used as a molecular marker for the analysis of chinical risk and prognosis of pediatric ALL.