ABSTRACT
Objective:To study the performance of immune reconstitution in patients with chimeric antigen receptor (CAR)-T cell immunotherapy bridging allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods:A total of 61 patients with acute B lymphocytic leukemia (B-ALL) who received CAR-T cell bridging allo-HSCT in Beijing Lu Daopei Hospital from August 2018 to December 2021 were enrolled, and the clinical medical records of the above patients were retrospectively analyzed. The average age was 14 (7, 30) years old, including 39 males and 22 females. 32 patients were treated with CAR-T cell immunotherapy(CAR-T Group) and 29 didn't with CAR-T cell immunotherapy(non-CAR-T group). The follow-up period was 561 (235,784) days. Multicolor flow cytometry was used to detect the peripheral blood lymphocyte subsets, i.e. total lymphocytes, T lymphocytes, helper T cells, cytotoxic T cells, B lymphocytes, NK cells, and Treg cell counts before transplantation and 1, 2, 3, 6, 8, 10, and 12 months after transplantation, to evaluate the immune reconstitution performance post allo-HSCT.Results:Serum globulin before transplantation: The IgA level in the CAR-T group was 0.18 (0.06, 0.49) g/L, which was lower than that of 1.03 (0.63, 1.56) g/L in the non-CAR-T group ( U=103.5, P<0.001). The IgG level in the CAR-T group was 5.54 (4.04, 7.09) g/L, lower than that of 6.78 (5.27, 9.26) g/L in the non-CAR-T group, ( U=1 298.5, P=0.017), and the IgM level in the CAR-T group was 0.18 (0.05, 0.30) g/L, lower than that of 0.40 (0.26, 0.71) g/L in the non-CAR-T group ( U=166.0, P<0.001). In the CAR-T group before transplantation, the absolute count of total lymphocyte in peripheral blood was 833.00 (335.00, 1 727.50) /μl, lower than that of 1 052.00 (545.75, 1 812.50) /μl in the non-CAR-T group ( U=404.0, P<0.001). The absolute count of T lymphocyte in the CAR-T group before transplantation was 686.00 (233.00, 1 307.00)/μl, lower than that of 860.00 (391.00, 1 419.75) /μl in the non-CAR-T group ( U=406.0, P<0.001). The absolute count of helper T lymphocytes in the CAR-T group was 146.00 (40.50, 327.50) /μl, lower than that of 162.50 (66.00, 384.75) /μl in the non-CAR-T group ( U=494.0, P=0.002). The absolute count of cytotoxic T lymphocytes in the CAR-T group was 343.00 (56.50, 924.00) /μl, lower than that of 478.00 (143.50, 992.25) /μl in the non-CAR-T group ( U=483.5, P=0.001). The absolute count of B lymphocytes in CAR-T group was 22.00 (6.00, 186.00) /μl, lower than that of 33.00 (8.00, 220.00) /μl in the non-CAR-T group ( U=498.0, P=0.002). And when two groups of patients were monitored after transplantation, there was no statistical difference in absolute cell counts of each immune cell subpopulation( P>0.05). Comparing the clinical features of the two groups, the pre-transplant history of the CAR-T group was 981.00 (368.50, 1 514.75) d, longer than that of 323.00 (167.50, 450.50) d in the non-CAR-T group ( U=263.0, P=0.004). The dose of rabbit anti-human thymic immunoglobulin (ATG) in the pretreatment protocol of patients in the CAR-T group was 5.00 (5.00, 7.50) mg/Kg, lower than that of 7.00 (5.00, 7.50) mg/kg in the non-CAR-T group ( U=288.5, P=0.018). The infusion dose of CD34 +cells in the CAR-T group was 5.91 (4.23, 6.02) ×10 6/kg, higher than that of 4.51 (4.00, 5.93)×10 6/kg in the non-CAR-T group ( U=291.0, P=0.012). The duration of the application of cyclosporine after transplantation in the CAR-T group was 167.00 (119.25, 299.50) d, which was shorter than that of 197.00 (102.50, 450.50) d in the non-CAR-T group ( U=421.0, P=0.001). Conclusions:For patients in CAR-T group with low immune function before transplantation, it may be possible to make them comparable to non-CAR-T group in immune reconstitution state by reducing the dose of pretreatment ATG, increasing the counts of CD34 + cells infusion in the graft, and discontinuing cyclosporine as soon as possible after transplantation.
ABSTRACT
Objective To investigate the differences in susceptibility to Lewis lung carcinoma and T lymphocyte subsets in the immune microenvironment between young and elderly mice.Methods Six C57/B6 mice at two months(young)and six mice at twelve months(aged)were injected with Lewis lung carcinoma cells at the dose of 1 × 106 in the left armpit to establish a murine model of lung carcinoma.The weight and tumor growth were monitored.Blood samples for routine blood tests were collected after 24 days.The proportions of CD4+ and CD8+T cells in the spleen were detected by flow cytometry,and the infiltration of CD4+,CD8+ T cells and related effector T cells in the tumor microenvironment were determined in the same way.Results The body weight of tumor bearing mice in the aged group was significantly higher than that in the young group(P ＜0.001);The tumor weight in the aged group(5.084±0.528)g was significantly higher than that in the young group(2.963 ±0.378)g(t =3,349,P =0.012);Routine blood tests showed that the numbers of leukocytes and subsets(except mononuclear)in the aged group were significantly lower than in the young group(P ＜0.05);Flow cytometry found that the effector and memory/effector CD4+T cell ratios in the spleen were significantly higher in the aged group than in the young group(P ＜0.001)and the expression of effector and memory/effector CD8+T cells in the tumor microenvironment was also significantly higher than in the young group(P ＜0.05);Quantitative expression values of IL-6 and IL-10 in the tumor microenvironment were 25090±3820 and 10670± 1793 in the aged group and 6252±864 and 3061±451 in the young group,respectively.Moreover,the expression levels of IL-6 and IL-10(t =3.925,P =0.01;t =3.552,P =0.02)in the tumor microenvironment in the aged group were significantly lower than those in the young group.Conclusions Young mice are more susceptible to Lewis lung carcinoma,probably as a result of differences in inflammation and immunity.