Objective:To investigate the efficacy and toxicity of blinatumomab in the first-line and second-line treatment of pediatric B-cell acute lymphoblastic leukemia (B-ALL).Methods:A multi-center retrospective cohort study was conducted to analyze clinical data from 323 pediatric B-ALL patients treated with blinatumomab across 14 hospitals in China from May 2021 to July 2023. Patients were divided into four groups based on the treatment phase and disease status when blinatumomab was used: relapsed/refractory group, post-consolidation minimal residual disease (MRD)-positive group, early MRD-positive group, and MRD-negative group. Blinatumomab for the relapsed/refractory group was considered as second-line treatment, while the other 3 groups as first-line treatment. The MRD negativity rate after treatment, the survival rates and the incidence of severe adverse events were compared across these groups. Patients who received blinatumomab for more than 7 days were included in the efficacy analysis. Survival analysis was performed using the Kaplan-Meier method, and Log-Rank test was used to compare the survival rates among groups.Results:Among the 323 patients, 191 (59.1%) were male, with the age of 6.2 (3.9, 10.5) years. There were 117 patients in the relapsed/refractory group, 62 cases in the post-consolidation MRD-positive group, 43 cases in the early MRD-positive group, and 101 cases in the MRD negative group. In the relapsed/refractory group, the complete remission rate and MRD negativity rate after one course of blinatumomab were 71.4% (35/49) and 81.5% (75/92) for the 49 children without complete remission and the 92 children with flow cytometry-positive MRD, respectively. In the post-consolidation MRD-positive group, the MRD negativity rates after one course of blinatumomab were 100.0% (27/27), 12/16 and 9/19 for patients with MRD positivity detected by flow cytometry, polymerase chain reaction and next-generation sequencing, respectively. In the early MRD-positive group, the MRD negativity rates were 96.7% (29/30) and 9/9 for flow cytometry and next-generation sequencing, respectively. The 2-year overall survival rate and event-free survival rate for the 319 children evaluable for efficacy were (90.6±1.7)% and (87.6±1.9)%, respectively, with the relapsed/refractory group showing significantly lower overall survival rates and event-free survival rate compared to the other groups ( χ2=21.40, 26.21,both P<0.001). Grade 3 or higher adverse events occurred in 128 cases (39.6%), with hematological toxicity observed in 101 cases, while cytokine release syndrome (CRS), infection, and neurotoxicity occurred in 11, 26 and 8 cases, respectively. In addition, there were statistically significant differences in the grade 3 or higher CRS among the four groups ( χ2=8.03, P<0.05). Conclusion:Blinatumomab can clear MRD more effectively and achieve superior survival outcomes when used as first-line treatment for pediatric B-ALL, with less CRS.

Glucose oxidase (GOD) is an oxygen-consuming dehydrogenase that can catalyze the production of gluconic acid hydrogen peroxide from glucose, and its specific mechanism of action makes it promising for applications, while the low catalytic activity and poor thermostability have become the main factors limiting the industrial application of this enzyme. In this study, we used the glucose oxidase AtGOD reported with the best thermostability as the source sequence for phylogenetic analysis to obtain the GOD with excellent performance. Six genes were screened and successfully synthesized for functional validation. Among them, the glucose oxidase AhGODB derived from Aspergillus heteromorphus was expressed in Pichia pastoris and showed better thermostability and catalytic activity, with an optimal temperature of 40 ℃, a specific activity of 112.2 U/mg, and a relative activity of 47% after 5 min of treatment at 70 ℃. To improve its activity and thermal stability, we constructed several mutants by directed evolution combined with rational design. Compared with the original enzyme, the mutant T72R/A153P showcased the optimum temperature increasing from 40 to 50 ℃, the specific activity increasing from 112.2 U/mg to 166.1 U/mg, and the relative activity after treatment at 70 ℃ for 30 min increasing from 0% to 33%. In conclusion, the glucose oxidase mutants obtained in this study have improved catalytic activity and thermostability, and have potential for application.
Glucose Oxidase/chemistry* ; Enzyme Stability ; Aspergillus/genetics* ; Pichia/metabolism* ; Temperature ; Catalysis ; Fungal Proteins/metabolism* ; Hot Temperature

Objective:To evaluate the efficacy of eculizumab in treating hematopoietic stem cell transplantation-associated thrombotic microangiopathy (TA-TMA) .Methods:This retrospective study included 11 patients who developed TA-TMA after allogeneic hematopoietic stem cell transplantation and subsequently received eculizumab treatment at Peking University People′s Hospital between June 2018 and May 2024. The incidence of TA-TMA, treatment details, and clinical outcomes were analyzed.Results:Among the 11 included patients [4 males, 7 females; median age: 29 years (range: 9-56) ], underlying diseases were severe aplastic anemia (SAA) in 5 patients, acute lymphoblastic leukemia (ALL) in 3 patients, and acute myeloid leukemia (AML) in 3 patients. The median time to TA-TMA diagnosis was 48 days post-transplantation (range: 4-213 days), and all patients met the diagnostic criteria for high-risk TA-TMA. The median interval from TA-TMA diagnosis to the initiation of eculizumab treatment was 12 days (range: 1-56 days). Patients received a median of 3 doses of eculizumab (range: 1-14). Ten of the 11 patients were assessed as having no response (NR) to eculizumab at the end of treatment or at death. One patient achieved a partial response (PR) but subsequently died after TA-TMA relapsed due to infection. At the last follow-up, all patients were either lost to follow-up or had died. The median follow-up duration was 88 days (range: 33-326 days), and the median time from TA-TMA diagnosis to the last follow-up was 31 days (range: 21-113 days) .Conclusion:Eculizumab demonstrated poor efficacy in this TA-TMA cohort. This might be attributable to the critical and complex condition of the patients, delayed initiation of eculizumab treatment, and insufficient dosage.

Objective:To evaluate the diagnostic value of targeted next-generation sequencing (tNGS) of throat swab samples for detecting community-acquired respiratory viruses (CARV) in patients with hematological diseases.Methods:Clinical and laboratory data from 64 episodes involving patients with hematological diseases and suspected infections—who underwent both pharyngeal swab tNGS and CARV polymerase chain reaction (PCR) testing concurrently—were retrospectively analyzed. The cases were drawn from the Department of Hematology, Peking University People’s Hospital, between September 2023 and April 2024. Concordance between tNGS and CARV PCR results, as well as the diagnostic performance of tNGS in detecting CARV, were evaluated.Results:Among the 64 episodes, 29 were clinically diagnosed with respiratory tract infections, including one case of cytomegalovirus pneumonia and 28 CARV-positive cases. The remaining 35 episodes involved patients with fever or respiratory symptoms attributed to other causes, including 14 with extrapulmonary infections and 21 with noninfectious etiologies. The median follow-up duration was 215.5 days (range: 7-271 days). PCR detected 24 strains of seven CARV types, whereas tNGS detected 25 strains of eight CARV types. Using PCR results as the reference standard, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of tNGS were 85.0%, 88.6%, 77.3%, 92.9%, and 87.5%, respectively. The two methods showed good concordance (Kappa=0.717, P<0.001) . Conclusion:Pharyngeal swab tNGS may serve as a viable alternative to PCR for diagnosing CARV infections in patients with hematological diseases.

Objective:To evaluate the efficacy of eculizumab in treating hematopoietic stem cell transplantation-associated thrombotic microangiopathy (TA-TMA) .Methods:This retrospective study included 11 patients who developed TA-TMA after allogeneic hematopoietic stem cell transplantation and subsequently received eculizumab treatment at Peking University People′s Hospital between June 2018 and May 2024. The incidence of TA-TMA, treatment details, and clinical outcomes were analyzed.Results:Among the 11 included patients [4 males, 7 females; median age: 29 years (range: 9-56) ], underlying diseases were severe aplastic anemia (SAA) in 5 patients, acute lymphoblastic leukemia (ALL) in 3 patients, and acute myeloid leukemia (AML) in 3 patients. The median time to TA-TMA diagnosis was 48 days post-transplantation (range: 4-213 days), and all patients met the diagnostic criteria for high-risk TA-TMA. The median interval from TA-TMA diagnosis to the initiation of eculizumab treatment was 12 days (range: 1-56 days). Patients received a median of 3 doses of eculizumab (range: 1-14). Ten of the 11 patients were assessed as having no response (NR) to eculizumab at the end of treatment or at death. One patient achieved a partial response (PR) but subsequently died after TA-TMA relapsed due to infection. At the last follow-up, all patients were either lost to follow-up or had died. The median follow-up duration was 88 days (range: 33-326 days), and the median time from TA-TMA diagnosis to the last follow-up was 31 days (range: 21-113 days) .Conclusion:Eculizumab demonstrated poor efficacy in this TA-TMA cohort. This might be attributable to the critical and complex condition of the patients, delayed initiation of eculizumab treatment, and insufficient dosage.

Objective:To evaluate the diagnostic value of targeted next-generation sequencing (tNGS) of throat swab samples for detecting community-acquired respiratory viruses (CARV) in patients with hematological diseases.Methods:Clinical and laboratory data from 64 episodes involving patients with hematological diseases and suspected infections—who underwent both pharyngeal swab tNGS and CARV polymerase chain reaction (PCR) testing concurrently—were retrospectively analyzed. The cases were drawn from the Department of Hematology, Peking University People’s Hospital, between September 2023 and April 2024. Concordance between tNGS and CARV PCR results, as well as the diagnostic performance of tNGS in detecting CARV, were evaluated.Results:Among the 64 episodes, 29 were clinically diagnosed with respiratory tract infections, including one case of cytomegalovirus pneumonia and 28 CARV-positive cases. The remaining 35 episodes involved patients with fever or respiratory symptoms attributed to other causes, including 14 with extrapulmonary infections and 21 with noninfectious etiologies. The median follow-up duration was 215.5 days (range: 7-271 days). PCR detected 24 strains of seven CARV types, whereas tNGS detected 25 strains of eight CARV types. Using PCR results as the reference standard, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of tNGS were 85.0%, 88.6%, 77.3%, 92.9%, and 87.5%, respectively. The two methods showed good concordance (Kappa=0.717, P<0.001) . Conclusion:Pharyngeal swab tNGS may serve as a viable alternative to PCR for diagnosing CARV infections in patients with hematological diseases.

Objective:To investigate the efficacy and toxicity of blinatumomab in the first-line and second-line treatment of pediatric B-cell acute lymphoblastic leukemia (B-ALL).Methods:A multi-center retrospective cohort study was conducted to analyze clinical data from 323 pediatric B-ALL patients treated with blinatumomab across 14 hospitals in China from May 2021 to July 2023. Patients were divided into four groups based on the treatment phase and disease status when blinatumomab was used: relapsed/refractory group, post-consolidation minimal residual disease (MRD)-positive group, early MRD-positive group, and MRD-negative group. Blinatumomab for the relapsed/refractory group was considered as second-line treatment, while the other 3 groups as first-line treatment. The MRD negativity rate after treatment, the survival rates and the incidence of severe adverse events were compared across these groups. Patients who received blinatumomab for more than 7 days were included in the efficacy analysis. Survival analysis was performed using the Kaplan-Meier method, and Log-Rank test was used to compare the survival rates among groups.Results:Among the 323 patients, 191 (59.1%) were male, with the age of 6.2 (3.9, 10.5) years. There were 117 patients in the relapsed/refractory group, 62 cases in the post-consolidation MRD-positive group, 43 cases in the early MRD-positive group, and 101 cases in the MRD negative group. In the relapsed/refractory group, the complete remission rate and MRD negativity rate after one course of blinatumomab were 71.4% (35/49) and 81.5% (75/92) for the 49 children without complete remission and the 92 children with flow cytometry-positive MRD, respectively. In the post-consolidation MRD-positive group, the MRD negativity rates after one course of blinatumomab were 100.0% (27/27), 12/16 and 9/19 for patients with MRD positivity detected by flow cytometry, polymerase chain reaction and next-generation sequencing, respectively. In the early MRD-positive group, the MRD negativity rates were 96.7% (29/30) and 9/9 for flow cytometry and next-generation sequencing, respectively. The 2-year overall survival rate and event-free survival rate for the 319 children evaluable for efficacy were (90.6±1.7)% and (87.6±1.9)%, respectively, with the relapsed/refractory group showing significantly lower overall survival rates and event-free survival rate compared to the other groups ( χ2=21.40, 26.21,both P<0.001). Grade 3 or higher adverse events occurred in 128 cases (39.6%), with hematological toxicity observed in 101 cases, while cytokine release syndrome (CRS), infection, and neurotoxicity occurred in 11, 26 and 8 cases, respectively. In addition, there were statistically significant differences in the grade 3 or higher CRS among the four groups ( χ2=8.03, P<0.05). Conclusion:Blinatumomab can clear MRD more effectively and achieve superior survival outcomes when used as first-line treatment for pediatric B-ALL, with less CRS.

Epstein-Barr virus (EBV) associated post-transplant lymphoproliferative disorders (PTLD) are one of the most severe complications after hematopoietic stem cell transplantation (HSCT). This study includes 31 cases of aplastic anemia (AA) patients who developed PTLD after haploidentical transplantation, summarizing their clinical characteristics and categorizing them into either rituximab monotherapy group or combination therapy group based on whether their condition improved by 1 log after a single dose of rituximab. The incidence of PTLD after HSCT in children with AA was 10.16%, and the incidence of PTLD in patients with age >10 years was significantly increased ( χ2=11.336, P=0.010). Of the 31 patients, 27 were clinically diagnosed and 4 were pathologically confirmed. Finally, 15 patients were classified into the rituximab treatment group and 15 patients into the combination treatment groups. Finally three patients died, and the 2-year overall survival rate was (89.7±5.6) %. Standard pre-treatment protocols and EBV reactivation are risk factors affecting the prognosis of PTLD. There was no statistically significant difference in the impact of the two treatment schemes on prognosis.

Objective:To investigate the efficacy and safety of venetoclax combined with the decitabine, cytarabine, and homoharringtonine (HHT) regimen and donor lymphocyte infusion (DLI) for the preventive and salvage therapy of pediatric acute myeloid leukemia (AML) /myelodysplastic syndrome (MDS) after allogeneic hematopoietic stem cell transplantation (HSCT) .Methods:A total of 29 relapsed pediatric/minimal residual disease-positive AML after HSCT were recruited at the Peking University Institute of Hematology from January 1, 2021, to June 1, 2023. They were treated with the above combination regimen and administered with DLI after 24-48 hours at the end of chemotherapy, and the treatment response and adverse reactions were regularly assessed.Results:The overall response rate (ORR) was 75.8%, CR rate was 88.9% (8/9) in the hematologic relapse group, and MRD negativity rate was 61.1% (11/18) in the MRD-positive group. The incidence of agranulocytosis, anemia, and thrombocytopenia with a classification above grade 3 were 100%, 82.7%, and 100%, respectively. The median time of the granulocyte deficiency period was 15 days. Acute graft-versus-host diseases (aGVHD) with a classification of grades Ⅲ-Ⅳ occurred in 11.1% of the patients after DLI, while moderate or severe cGVHD occurred in 7.4% of the patients. The single risk factor for ORR was MNC counts of less than 10×10 8/kg, and the relapse occurred within 100 days. At a median follow-up of 406 days, the 1-year OS was 65%, and the 1-year OS was 57% in the group with no reaction ( P=0.164) compared with 71% in the group who had an overall reaction. Conclusion:The combined regimen based on the DAC, VEN, and modified HA regimen showed a high response rate in the salvage therapy for pediatric AML after the relapse of HSCT. However, bridging to transplantation should be performed immediately after remission to result in a long survival rate.