Establishment of Reproducible Xenotransplantation Model of T Cell Acute Lymphoblastic Leukemia in NOD/SCID Mice

T cell acute lymphoblastic leukemia(T-ALL) is an aggressive leukemia.However the poor prognosis and low morbidity restrict further analysis of the disease.Therefore there is an increasing demand to develop animal models for identifying novel therapeutic approaches.In this study,we inoculated the anti-mouse CD122 monoclonal antibody conditioned NOD/SCID mice with the leukemia cells from 9 T-ALL patients and 1 cell line via the tail vein.Four of the 9 patients and the cell line were successfully engrafted.Flow cytometry detected high percentage of human CD45 + cells in recipient mice.Immunohistochemistry showed infiltration of human CD45 + cells in different organs.Serial transplantation was also achieved.In vivo drug treatment showed that dexamethasone could extend survival,which was consistent with clinical observation.These results demonstrated that we successfully established 5 xenotransplantation models of T-ALL in anti-mCD122 mAb conditioned NOD/SCID mice,which recapitulated the characteristics of original disease.

The Role of Kappa and Lambda in Subclassification of B Cell Lymphoblastic Leukemia in Sudanese Patients Using Flow Cytometry

Background: B-cell Acute lymphoblastic leukemia (B-ALL) is a neoplasm of lymphoblasts which are of B-cell lineage typically composed of small to medium sized blast cells, moderately condensed to dispersed chromatin with scanty cytoplasm and inconspicuous nucleoli, involving the bone marrow and/or blood. Methods and materials: This is a prospective cross-sectional study in which 50 blood and/or bone marrow samples of newly diagnosed patients (B-ALL) were tested for immunophenotyping. All samples were prepared for surface and cytoplasmic markers including kappa and lambda human antibody for 10 minutes in dark place and then run by the Flow Cytometer. Results: 64% of the study populations were males and 36% were females. Cases were classified according to immunophenotype and the age into different subtypes and showed the following frequencies: Pro B-ALL (8%), early pre B-ALL (56%), common B-ALL (16%), Pre-B-ALL (14%) and Mature B-ALL (only 6%). Surface immunoglobulin was positive in 10% and negative in 90% of all patients, showing 100% positivity in mature B-ALL and totally negative in other subtypes. While cytoplasmic immunoglobulin was positive in 16% and negative in 84% of all patients and was positive in 100% of Pre-B-ALL and in 50% of mature B-ALL. Surface kappa was more expressed in mature B-ALL than lambda giving a ratio of 2:1, while cytoplasmic kappa:lambda was 6:1 in Pre-B-ALL. Conclusion: Kappa and lambda have important role in B-ALL classification which necessitates their presence in immunophenotyping of B-ALL.

Is there a role for B lymphocyte chimerism in the monitoring of B-acute lymphoblastic leukemia patients receiving allogeneic stem cell transplantation?

Objective: To determine the sensitivity and significance of B-cell chimerism for the detection of early engraftment, transplant rejection, and disease relapse. Methods: The dynamic monitoring of lineage-specific cell subtypes (B, T, and NK cells) was made in 20 B-cell acute lympho-blastic leukemia (B-ALL) patients following allogeneic hematopoietic stem cell transplantation (allo-HSCT). In the early period after allo-HSCT, the latest establishment of B-cell complete chimerism (CC) was observed in a majority of patients. Results: The percentage of donor cells of B-cell lineage was lower than the percent of T-cell lineage in most of the mixed chimerism (MC) patients. During graft rejection, the frequency of patients with decreasing MC of B-, T-and NK-cell lineage were 5/5, 2/5, and 2/5. When disease relapsed, five patients showed a faster decrease of the donor percent of B-cells than of T-or NK-cells. Only one patient displayed a more rapid decrease in NK-cells than in T-or B-cells. Conclusion: Monitoring of B-cell chimerism after HSCT seems to be valuable for insuring complete engraftment, anticipating graft rejection, and relapse in B-ALL patients. Copyright ? 2015, Chinese Medical Association Production. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

An analytical biomarker for treatment of patients with recurrent B-ALL after remission induced by infusion of anti-CD19 chimeric antigen receptor T(CAR-T) cells

Anti-CD19 chimeric antigen receptor-modified T(CAR-T-19) cells have emerged as a powerful targeted immunotherapy for B-cell lineage acute lymphoblastic leukemia with a remarkable clinical response in recent trials. Nonetheless, few data are available on the subsequent clinical monitoring and treatment of the patients, especially those with disease recurrence after CAR-T-19 cell infusion. Here, we analyzed three patients who survived after our phase I clinical trial and who were studied by means of biomarkers reflecting persistence of CAR-T-19 cells in vivo and predictive factors directing further treatment. One patient achieved 9-week sustained complete remission and subsequently received an allogeneic hematopoietic stem cell transplant. Another patient who showed relapse after 20 weeks without detectable leukemia in the cerebrospinal fluid after CAR-T-19 cell treatment was able to achieve a morphological remission under the influence of stand-alone low-dose chemotherapeutic agents. The third patient gradually developed extensive extramedullary involvement in tissues with scarce immune-cell infiltration during a long period of hematopoietic remission after CAR-T-19 cell therapy. Long-term and discontinuous increases in serum cytokines(mainly interleukin 6 and C-reactive protein) were identified in two patients(Nos. 1 and 6) even though only a low copy number of CAR molecules could be detected in their peripheral blood. This finding was suggestive of persistent functional activity of CAR-T-19 cells. Combined analyses of laboratory biomarkers with their clinical manifestations before and after salvage treatment showed that the persistent immunosurveillance mediated by CAR-T-19 cells would inevitably potentiate the leukemia-killing effectiveness of subsequent chemotherapy in patients who showed relapse after CAR-T-19-induced remission.

γANDδCHAIN GENE REARRANGEMENT OF T CELL RECEPTOR IN ACUTE LYMPHOBLASTIC LEUKEMIA

The immunophenotype, rearrangements of T cell receptor(TCR) γ andδchain genes as well as the immunoglobulinheavy chain (IgH)gene were studied in 37 cases ofmorphologically defined acute lymphoblastic leukemia (ALL).According to the expression of differentiation antigens, 8 caseswere classified as T-ALL, 26 B lineage ALL, 2 acute un-differentiated leukemia (AUL) and myeloid phenotype. An or-der of TCR gene rearrangements was observed in T-ALL,with the rearrangement of δgene preceding that of γgene.Both genes were also found frequently rearranged and / or de-leted in high proportions of the ALL of B cell lineage. Howev-er, the patterns of gene rearrangements were somewhat differ-ent between the T and B lineage ALLs. In contrast, the lgHgene rearrangements were observed only in the B lineage ALL.The immunogenotype analysis of ALL proved to be a usefulmarker of the clonality and provided us with important informa-tion on early human lymphoid differentiation. We concludethat the determination of T