Co-infusion of haplo-identical CD19-chimeric antigen receptor T cells and stem cells achieved full donor engraftment in refractory acute lymphoblastic leukemia

Abstract Background Elderly patients with relapsed and refractory acute lymphoblastic leukemia (ALL) have poor prognosis. Autologous CD19 chimeric antigen receptor-modified T (CAR-T) cells have potentials to cure patients with B cell ALL; however, safety and efficacy of allogeneic CD19 CAR-T cells are still undetermined. Case presentation We treated a 71-year-old female with relapsed and refractory ALL who received co-infusion of haplo-identical donor-derived CD19-directed CAR-T cells and mobilized peripheral blood stem cells (PBSC) following induction chemotherapy. Undetectable minimal residual disease by flow cytometry was achieved, and full donor cell engraftment was established. The transient release of cytokines and mild fever were detected. Significantly elevated serum lactate dehydrogenase, alanine transaminase, bilirubin and glutamic-oxalacetic transaminase were observed from days 14 to 18, all of which were reversible after immunosuppressive therapy. Conclusions Our preliminary results suggest that co-infusion of haplo-identical donor-derived CAR-T cells and mobilized PBSCs may induce full donor engraftment in relapsed and refractory ALL including elderly patients, but complications related to donor cell infusions should still be cautioned. Trial registration Allogeneic CART-19 for Elderly Relapsed/Refractory CD19+ ALL. NCT0279955

Expert Consensus on Microtransplant for Acute Myeloid Leukemia in Elderly Patients -Report From the International Microtransplant Interest Group

Recent studies have shown that microtransplant (MST) could improve outcome of patients with elderly acute myeloid leukemia (EAML). To further standardize the MST therapy and improve outcomes in EAML patients, based on analysis of the literature on MST, especially MST with EAML from January 1st, 2011 to November 30th, 2022, the International Microtransplant Interest Group provides recommendations and considerations for MST in the treatment of EAML. Four major issues related to MST for treating EAML were addressed: therapeutic principle of MST (1), candidates for MST (2), induction chemotherapy regimens (3), and post-remission therapy based on MST (4). Others included donor screening, infusion of donor cells, laboratory examinations, and complications of treatment

Hepatocyte growth factor gene-modified adipose-derived mesenchymal stem cells ameliorate radiation induced liver damage in a rat model.

Liver damage caused by radiotherapy is associated with a high mortality rate, but no established treatment exists. Adipose-derived mesenchymal stem cells (ADSCs) are capable of migration to injured tissue sites, where they aid in the repair of the damage. Hepatocyte growth factor (HGF) is critical for damage repair due to its anti-apoptotic, anti-fibrotic and cell regeneration-promoting effects. This study was performed to investigate the therapeutic effects of HGF-overexpressing ADSCs on radiation-induced liver damage (RILD). ADSCs were infected with a lentivirus encoding HGF and HGF-shRNA. Sprague-Dawley (SD) rats received 60Gy of irradiation to induce liver injury and were immediately given either saline, ADSCs, ADSCs + HGF or ADSCs + shHGF. Two days after irradiation, a significant reduction in apoptosis was observed in the HGF-overexpressing ADSC group compared with the RILD group, as assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Scanning electron microscopy showed chromatin condensation after irradiation, which was ameliorated in the group that received ADSCs and was reversed in the group that received HGF-overexpressing ADSCs. HGF-overexpressing ADSCs ameliorated radiation- induced liver fibrosis through down regulation of α-SMA and fibronectin. Hepatocyte regeneration was significantly improved in rats treated with ADSCs compared with rats from the RILD group), as assessed by Ki-67 immunohistochemistry. Rats that received HGF-overexpressing ADSCs showed an even greater level of hepatocyte regeneration. HGF-overexpressing ADSCs completely blocked the radiation-induced increase in the enzymes ALT and AST. The effect of mitigating RILD was compromised in the ADSC + shHGF group compared with the ADSC group. Altogether, these results suggest that HGF-overexpressing ADSCs can significantly improve RILD in a rat model, which may serve as a valuable therapeutic alternative

HGF gene-modified ADSCs migrate to damaged tissue sites.

<p>(A) TUNEL staining of liver sections from the control group and liver sections from the RILD group 2 days post-irradiation. Arrows indicate hepatocytes that are positive for TUNEL staining. (B) Quantification of TUNEL-positive cells. Five fields were randomly selected from each specimen, and the number of TUNEL-positive cells was determined (×400). (C) HE stain of liver specimens obtained from the control group and from the RILD group 60 days after irradiation. Arrow indicates vacuolar degeneration in liver. (D) ADSCs expressing GFP were detected in rat liver 7, 14 and 30 days after transplantation (100×). Arrows indicate cells positive for GFP staining. (E) HGF was detected by ELISA in rat liver 2 weeks after transplantation. *<i>p</i><0.05.</p

Evaluation of hepatocyte apoptosis 2 days after irradiation.

<p>(A) Images of hepatocytes from an electron microscope (×8200). (B) TUNEL staining of liver specimens from all five groups (×400). (C) Quantification of cells that were positive for TUNEL staining: five random fields (200×) were selected from within each liver section, and TUNEL-positive cells were counted. Data are expressed as the mean ± SD. *<i>p</i><0.05.</p

Construction of HGF gene-modified ADSCs.

<p>(A) Micrographs of cultured ADSCs at passage three. (B) Surface antigens of ADSCs were analyzed by flow cytometry. Freshly cultured ADSCs were positive for CD90 (99%), but not for CD31 (0.02%), CD34 (0.02%), or CD45 (0.03%). (C) Infection efficiency 4 days post-infection. GFP-expressing ADSCs were detected and counted using fluorescence microscopy. The infection efficiency was 100%. (D) Expression of HGF mRNA as detected by RT-RCR 4days post-transfection. (E) Expression of HGF protein as detected by ELISA 4days post-transfection. *<i>p</i><0.05.</p

Analysis of liver function index.

<p>Serum levels of ALT (A) and AST (B) 2 days after irradiation are shown. *<i>p</i><0.05.</p

Assessment of hepatocyte proliferation.

<p>(A) Histological analysis of liver sections stained with a Ki-67 antibody (400×). Arrow indicates hepatocytes that are positive for Ki-67 staining. (B) Quantification of Ki-67-positive cells. Five random fields (400×) were selected from within each liver section, and the number of Ki-67-positive cells was counted. Data are expressed as the mean ± SD. *<i>p</i><0.05.</p

A Modified Haploidentical Nonmyeloablative Transplantation without T Cell Depletion for High-Risk Acute Leukemia: Successful Engraftment and Mild GVHD

AbstractSevere graft-versus-host disease (GVHD) and graft rejection still remain major complications of haploidentical nonmyeloablative (NMA) stem cell transplantation. Recent studies have shown that bone marrow-derived mesenchymal stem cells (MSCs) possess immunomodulatory capacity and may promote hematopoietic engraftment. The purpose of this study was to observe if the new strategy, which included a haploidentical peripheral blood stem cell transplantation (PBSCT) combined with MSCs, modified NMA conditioning, and GVHD prophylaxis would improve donor engraftment and prevent severe GVHD. The modified conditioning approach consisted of fludarabine (Flu), low-dose total body irradiation (TBI), cyclophosphamide (Cy), cytarabine, and anti-Tcell-lymphocyte globulin, whereas the GVHD prophylaxis consisted of cyclosporin A (CsA), mycophenolate mofetil (MMF), anti-CD25 antibody and intrabone marrow injection of MSCs. Thirty-three patients with high-risk acute leukemia underwent transplantation with PBSC from HLA-haploidentical donors without T cell depletion. All of the patients achieved full donor chimerisms, including 6 who switched to full donor chimerisms from mixed chimerisms in 1 to 2 months after the transplantations. Rapid hematological engraftment was observed with neutrophils >0.5×109/L at day 11 and platelets >20×109/L at day 14. Fifteen patients (45.5%) developed grade I–IV acute GVHD (aGVHD) and only 2 (6.1%) developed grade III to IV aGVHD. Nine (31%) of 29 evaluable patients experienced chronic GVHD (cGVHD). Upon follow-up for 1.5 to 60 months, 20 (60.6%) patients were alive and well and 6 (18.2%) had relapsed leukemia in the 33 patients. The probability of 3-year survival was 57.2%. The results indicate that this new strategy is effective in improving donor engraftment and preventing severe GVHD, which will provide a feasible option for the therapy of high-risk acute leukemia