Treatment response of a two-dose regimen of dose-adjusted inotuzumab ozogamicin in relapsed/refractory B-cell acute lymphoblastic leukemia / 中华血液学杂志

Objective: To observe the treatment response of a two-dose regimen of inotuzumab ozogamicin (inotuzumab), a monoclonal antibody targeting CD22, for patients with heavily treated relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL), including those failed or relapsed after chimeric antigen receptor (CAR) -T-cell therapy. Methods: Pediatric and adult patients who received two doses of inotuzumab and who were evaluated after inotuzumab treatment were included. Antibody infusions were performed between March 2020 and September 2022. All patients expressed CD22 antigen as detected by flow cytometry (>80% leukemic cells displaying CD22) before treatment. For adults, the maximum dosage per administration was 1 mg (with a total of two administrations). For children, the maximum dosage per administration was 0.85 mg/m(2) (no more than 1 mg/dose; total of two administrations). The total dosage administered to each patient was less than the standard dosage of 1.8 mg/m(2). Results: Twenty-one patients with R/R B-ALL were included, including five children (<18 years old) and sixteen adults. Seventeen patients presented with 5.0% -99.0% leukemic blasts in the bone marrow/peripheral blood or with extramedullary disease, and four patients were minimal residual disease (MRD) -positive. Fourteen patients underwent both CD19 and CD22 CAR-T-cell therapy, four underwent CD19 CAR-T-cell therapy, and three underwent blinatumomab therapy. Eleven patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). After inotuzumab treatment, 14 of 21 patients (66.7% ) achieved a complete response (CR, one was MRD-positive CR), and all four MRD-positive patients turned MRD-negative. Four of six patients who failed recent CD22 CAR-T-cell therapy achieved a CR after subsequent inotuzumab treatment. Seven patients (33.3% ) demonstrated no response. Grade 1-3 hepatotoxicity occurred in five patients (23.8% ), one child with no response experienced hepatic veno-occlusive disease (HVOD) during salvage transplantation and recovered completely. Conclusion: For patients with heavily treated R/R B-ALL, including those who had undergone allo-HSCT and CD19/CD22 CAR-T-cell therapy, the two-dose regimen of inotuzumab resulted in a CR rate of 66.7%, and the frequency of hepatotoxicity and HVOD was low.

Tumor-killing effects of CD19 and CD22 bi-specific CAR-T cells on tumor cells / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：设计并制备一种分别靶向B细胞表面抗原CD19和CD22的CAR-T细胞，检测其对肿瘤细胞的体内外杀伤效果。方法：将含有人源化 CD19 ScFv的二代CAR分子和带有CD3ε链作为共刺激结构域的CD22 ScFv CAR分子以P2A自剪切肽连接，序列连接于慢病毒载体pLTR-CMV-MCS中，以HEK-293T细胞包装相应的慢病毒载体，感染健康志愿者提供的T细胞制备CAR-19-22-T细胞，同时以相同二代结构分别构建单靶向CAR-T细胞作为参照。构建表达荧光素酶、CD19和/或CD22的前列腺癌3M细胞（靶细胞）。将各种CAR-T细胞与靶细胞共同培养，采用荧光素酶化学发光法和ELISA法检测其对靶细胞的杀伤能力和细胞因子的分泌水平。通过尾静脉注射Raji-Luc细胞构建NOD-SCID免疫缺陷小鼠白血病模型，分别注射各组CAR-T细胞进行治疗并评估其疗效。结果：培养7 d的CAR-19-22-T细胞的CAR-19表达率为13.7%，CAR-22表达率为14.3%。CAR-19-22-T细胞在10∶1效靶比时，对3M-CD19-Luc、3M-CD22-Luc和3M-CD19-CD22-Luc细胞的杀伤率均显著高于T细胞[（78.1±14.4）% vs （11.1±4.3）%、（46.7±10.7）% vs （12.4±2.7）%、（90.5±4.3）% vs （14.3±3.7）%，均P<0.01]；与3M-CD19-Luc、3M-CD22-Luc、3M-CD19-CD22-Luc靶细胞共培养后，CAR-19-22-T细胞IFN-γ、TNF-α和IL-2水平均显著低于CAR-19-T和CAR-22-T细胞（P<0.05或P<0.01）。CAR-19-22-T细胞对移植Raji-Luc细胞模型小鼠治疗效果明显，其生存期显著长于T细胞组（P<0.01），与CAR-19-T组和CAR-22-T组荷瘤小鼠比较差异均无统计学意义（均P>0.05）。结论：成功设计并制备了一种双靶点CAR-19-22-T细胞，其能够有效杀伤表达CD19和/或CD22抗原的肿瘤细胞，对Raji-Luc细胞的白血病模型小鼠有显著的治疗效果。

Epidemiology and Patterns of Leukemia in Northern Saudi Arabia

Objective: The aim of the present study was to determine the patterns of leukemia in Northern Saudi Arabia. Methodology: This was a retrospective descriptive study conducted in King Khalid hospital, Hail, Kingdom of Saudi Arabia (KSA) including records of leukemia from 2008 to 2016. Results: The overall Crude Incidence Rate (CIR) of leukemia was 7.45 per 100.000 person-year, including patients diagnosed with different patterns of leukemia in Northern Saudi Arabia. The mean age of patients was 45.4 years with a minimum of 5 years and a maximum of 107 years old. Around 43 (59%) were males and 30 (41%) were females. Conclusion: The incidence rates of leukemia are relatively higher in Northern Saudi Arabia, with an increase of all subtype.

Immunophenotypic characteristics of CD19 chimeric antigen receptor( CAR)-transfected Nalm-6 cells / 中华微生物学和免疫学杂志

Objective To investigate the immunophenotypic characteristics of potential leukemia cells transfected with CD19 antigen receptor( CAR) during CAR-T cell preparation. Methods Morphological chan-ges in CD19 CAR-transfected cells were observed under inverted microscope. The transfection rate and immuno-phenotype of transfected Nalm-6 cells were analyzed by flow cytometry. Secretion of cytokines in the culture sys-tem was detected by chemiluminescence. Results The transfection rate of Nalm-6 cells by CD19 CAR was (46. 50±3. 78) ％ and that of KG1a cells was (15. 70±1. 22) ％. CD19 CAR-transfected Nalm-6 cells prolifer-ated more rapidly than Nalm-6 cells ( P values on 0 d, 4 d, 7 d and 12 d were 6. 339, 3. 447, 0. 012 and 0. 009). In the culture of CD19 CAR-transfected Nalm-6 cells, cell aggregation and adhesion were observed and they gradually gathered into a group. The rate of CD19 expression was only 1. 19％ in the CD19 CAR-transfect-ed Nalm-6 cell culture system with the transfection rate of (46. 50±3. 78) ％. After increasing the proportion of Nalm-6 cells in the culture system, CD19 expression was gradually increased, while the expression of CD22 re-mained stable. CD19 expressed by Nalm-6 cells cultured in the supernatant of CD19 CAR-transfected Nalm-6 cell culture system was decreased gradually. The levels of IL-10 and TNF-αsecreted by CD19 CAR-transfected Nalm-6 cells were higher than those by Nalm-6 cells. Conclusions Results of the immunophenotypic analysis of CD19 CAR-transfected leukemia cells suggested that CD22 CAR-T cell therapy could be used as a rescue or combination therapy for CD19 CAR transfection into leukemia cells.

Lymphocyte Immunophenotype of Chronic Myelogenous Leukemia / 대한혈액학회지

BACKGROUND: Detection of bcr/abl fusion mRNA using reverse transcription polymerase chain reaction has been used for diagnosis of chronic myelogenous leukemia (CML) and monitoring after treatment. However, this conventional method is not quantitative. Therefore, new quantitative marker for CML is necessary for the follow-up of the patients after treatment including bone marrow transplantation. Whether the lymphocytes are involved in CML clone or not is still a moot question. If the lymphocytes are involved in CML clone, there could be an abnormal surface antigen expressed on these cells. We tried to find out abnormal surface antigen expression on the lymphocytes of CML. METHODS: We analyzed the immunophenotypic distribution of the bone marrow lymphocytes using flow cytometry in 22 cases of CML and 20 normal persons, and searched for characteristic abnormal immunophenotype of CML. Both peripheral blood and bone marrow samples were analyzed using dual color immunophenotying for CD19 and CD22 expression in 14 cases of CML. RESULTS: The proportion of lymphocytes with T cell antigen expression and CD10, CD19, CD20 expression were lower in CML than in normal control (P<0.05). In contrast to these antigens, the proportion of CD22 positive lymphocytes was higher in CML than in normal control (P=0.0434). And loss of correlation between CD19 and CD22 expression was observed in CML. The proportion of CD19-/CD22+ lymphocytes in the bone marrow of 14 cases of CML was higher than that of normal control (P=0.0001). The proportion of CD19-/CD22+ lymphocytes in the peripheral blood of CML was 45.0+/-22.6%, and higher than 1.0+/-0.3% of normal control (P= 0.0000). The proportion of CD19-/CD22+ lymphocytes in the peripheral blood was higher than that of the bone marrow (P=0.0018). CD22 was not coexpressed with T cell antigens (CD2, CD3) or myeloid antigen (CD14) in CML or normal control. CONCLUSION: We demonstrated that the cells, representing unusual immunophenotype of CD19-/ CD22+, are characteristically increased in the bone marrow and peripheral blood of CML. This immunophenotype could be a valuable marker for the diagnosis of CML and monitoring after treatment.

Clinical Significance of Membrane CD22 in B-lineage Acute Lymphoblastic Leukemia / 대한임상병리학회지

BACKGROUND: CD22 is a glycoprotein expressed on the surface of normal mature B cells and in the cytoplasm of normal B cell precursors. Cytoplasmic CD22 (cCD22) has been proposed as a immunologic marker for the diagnosis of B-lineage acute lymphoblastic leukemia (ALL) while membrane CD22 (mCD22) has been used as the marker for chronic lymphocytic leukemia, B-lineage lymphoma, and hairly cell leukemia, and mCD22 has not been routinely used for the diagnosis and subgrouping of ALL. The purpose of this study was to examine the expression of mCD22 in B-lineage ALL and its clinical significance. METHODS: From 1992 to April, 1998, the leukemic cells of 64 patients newly diagnosed as B-lineage ALL by immunophenotyping were analyzed by the direct immunofluorescence method using monoclonal antibodies including mCD22. RESULTS: mCD22 was positive in 53% (34/64) of all patients, 50% (21/42) of children and 59% (13/22) of adults. According to the immunologic classification, mCD22 was positive in 44% (4/9) of group II, 53% (19/36) of group III, 69% (11/16) of group IV, but negative in 3 cases of group V and VI. The complete remission rate of the mCD22 negative group in group III was significantly higher than that of the mCD22 positive group (P=0.008). There were significant differences in survival rates between the mCD22 positive group and the mCD22 negative group in group II, III and IV (P=0.046) and the above observed significant difference was seen when group III was separately tested (P=0.014). CONCLUSIONS: Our study demonstrated that the expression of mCD22 may be a poor prognostic factor in B-lineage ALL and that mCD22 shall be clinically used as a prognostic marker especially in group III, which is most common among the subgroups of B-lineage ALL.