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Objective: To detect the gene mutations in patients with myeloid malignancies by high-throughput sequencing and explore the correlation between gene mutations and prognosis., Methods: A retrospective analysis was performed on 56 patients with myeloid malignancies who were hospitalized in the department of hematology, Peking University International Hospital from January 2020 to May 2021. The genetic mutations of the patients were detected by next-generation sequencing technology, and the correlation between the genetic mutations and prognosis of myeloid malignancies was analyzed., Results: In 56 patients, the number of mutated genes detected in a single patient is 0-9, with a median of 3. Sequencing results showed that the most common mutated genes were RUNX1 (21.4%), TET2 (17.9%), DNMT3A (17.9%), TP53 (14.3%) and ASXL1 (14.3%), among which the most common mutations occurred in the signaling pathway-related genes (23.3%) and the transcription factor genes (18.3%). 84% of the patients carried multiple mutated genes (≥2), and correlation analysis showed there were obvious co-occurring mutations between WT1 and FLT3 , NPM1 and FLT3-ITD , and MYC and FLT3. TP53 mutation was more common in MDS patients.The overall survival time of patients with NRAS mutation was significantly shortened ( P =0.049). The prognosis of patients with TP53 mutation was poor compared with those without TP53 mutation, but the difference wasn't statistically significant ( P =0.08)., Conclusion: The application of next-generation sequencing technology is of great significance in myeloid malignancies, which is helpful to better understand the pathogenesis of the disease, to judge the prognosis and to find possible therapeutic targets.

Objective: To investigate the efficacy and safety of CD19/CD3 bisecific monoclonalantibody (Blinatumomab) in the treatment of adult patients with relapsed / refractory Ph-negative acute B-lymphoblastic leukemia (R/R-B-ALL)., Methods: Ten adult R/R B-ALL patients were all treated with Blinatumomab. Each treatment cycle was administered for 28 days and stopped for 14 days. The dose was 9 μg/day for the first 7 days of cycle 1, and 28 μg/day for days 8-28 if there were no adverse reactions. From the second cycle onwards, the daily dose was 28 μg. The remission, survival time (EFS and OS) and adverse reactions were observed after treatment., Results: Nine patients with curative effect could be evaluated. Four patients achieved CR after one course, and one patient achieved CR after two courses, the overall remission rate was 55.6%(5/9). The median EFS was 4 months (1-12 months), and the median OS was 6 months (2-44 months). Nine of the 10 patients had fever of different degrees. Serum levels of cytokines such as IL-6, IL-10, IL-17 and IFN-γ increased. Two patients resumed medication after 1 week of treatment interruption due to neurotoxicity and CRS, respectively. One patient was discontinued due to grade 3 CRS and died of tropical candidiaemia., Conclusion: Blinatumomab has a good response rate in the treatment of relapsed/refractory B-ALL patients, but the duration of remission is shorter. Drug-related adverse reactions are mainly CRS and neurotoxicity. Inflammatory factors IL-6, IL-10, IL-17 and IFN-γ can be used as indicators to monitor CRS. The bisspecificity MAbs provide an opportunity for subsequent allogeneic hematopoietic stem cell transplantation in R/R-B-ALL patients.

AbstractObjective: To investigate the clinical phenotype and genotype of an ACTN1-associated thrombocytopenic family and explore its molecular pathogenesis., Methods: All the family members' peripheral blood was collected for routine blood tests, blood smear, coagulation function, and platelet aggregation test. Flow cytometry was used to detect the expression of platelet CD41 and CD61. The proband and her father were tested bone marrow cytomorphology. Whole-exome sequencing techniques were performed to detect and uncover mutant loci of suspected pathogenic genes. Bioinformatics was used to assess the conserved nature of the mutated loci and to analyze the effect of the mutated genes leading to the function of the corresponding amino acid sequences., Results: The platelet count of the proband was 88×10 9 /L, and the blood smear showed dumbbell-shaped platelets, snake-shaped platelets and platelets of various sizes. Her bone marrow cytomorphology revealed normal megakaryocyte morphology with a count of 270. The platelet count of the proband's father was 74×10 9 /L, with large platelets and platelets of various sizes observed in the blood smear, and the morphology of megakaryocytes was normal in bone marrow with a megakaryocyte count of 239. Her grandfather had a platelet count of 83×10 9 /L, with snake-shaped platelets and platelets of various sizes on blood smears. Other family members were normal in all tests. The missense mutation c.2396G > A in exon 20 of the ACTN1 gene in the proband resulted in the mutation of 799 amino acids of the encoded protein, i.e., Arg, to His. The sequencing results of her father and grandfather at this locus were found to be consistent with her. Furthermore, bioinformatics analysis indicated that the locus was highly conserved across species and that variation in this locus might lead to functional impairment of the protein. The protein model analysis demonstrated that α-actin-1 at position 799 Arg and Glu at position 811 could form a critical salt bridge which stabilizes the conformation of the Ca2 + binding loop within the calmodulin-like motif. the mutation of R799H lost this critical salt bridge and destabilized this structural domain., Conclusion: In the present study, the newly uncovered missense mutation c.2396G＞A in exon 20 of the ACTN1 gene is potentially the molecular mechanism for the thrombocytopenia.