Successful Anti-CLL1 CAR T-Cell Therapy in Secondary Acute Myeloid Leukemia.

Secondary acute myeloid leukemia (sAML) is a high-risk AML evolving from heterogenous prior hematological disorders. Compared to de novo AML, sAML has even worse responses to current therapy and thus is associated with lower remission rates, inferior overall survival (OS) and higher relapse rates. Many efforts have been devoted to improving the overall but with limited success, and novel strategy is thus highly needed. Recent research has identified that CLL1 is highly expressed on AML leukemia stem cells and blasts cells but not on normal hematopoietic stem cells. In this case report, we treated a secondary AML patient with anti -CLL1 CAR-T therapy and achieved morphological, immunophenotypic and molecular complete remission for over 10 months. Although only one successful case is presented here, the anti-CLL1 CAR T-cells should be considered as another treatment option for secondary AML in the future.

Assessment of iron overload in very young children with limited thalassemia care resources in South China.

Southern China has one of the world's largest population of patients needing transfusions. Transfusion and chelation are not uniformly available and no magnetic resonance imaging (MRI) assessment data exists to date. A total of 153 young ß-thalassemia major (ß-TM) patients were assessed using a validated 1.5T scanner in Hong Kong, People's Republic of China (PRC). Their median age was 13 (range 7 to 30), and most patients were young (22.0% age <10, 73.0% age <15, 88.0% age <18). Erratic health care made estimation of total transfusion and chelation exposure impossible. Despite their early age, 24.0% had severe cardiac hemosiderosis [T2*<10 milliseconds (ms)], at ages as early as 8 years old. Median heart iron was 1.68 mg/g dry weight (range 0.19-7.66) and increased with age (p = 0.017), while liver iron was 22.2 mg/g dry weight (range 3.15 to 39.2). Serum ferritin levels were poor predictors of heart and liver, or pancreatic R* and pituitary R* values. Magnetic resonance imaging scans are needed to screen very young ß-TM patients with immediate risk of premature cardiac death in developing nations and triage them to more intensive treatment. This is particularly important in countries with a large number of patients and limited resources. Our data suggests that in developing countries, there is no lower limit for thalassemia MRI scanning programs.

[Influence of total nucleated cell dose on the efficacy of cord blood transplantation].

OBJECTIVE: To study the influence of cord blood total nucleated cell (TNC) dose on the efficacy of cord blood transplantation in children. METHODS: Thirty-four children with hematological disease received cord blood transplantation. They were assigned to 3 groups according to the infused TNC dose: TNC>10 x 10(7)/kg (n=7), 10 x10(7)/kg>TNC> or =7 x 10(7)/kg (n=9) and TNC<7 x 10(7)/kg (n=18). The rates of graft and rejection of hematopoietic stem cells and the efficacy of transplantation were examined in the three groups. RESULTS: All 7 children in the group infused with TNC >10 x 10(7)/kg got a long-term stable engraftment. The median time of absolute neutrophil count >0.5 x 10(9)/L was 14.8 days (range 12-20 days) and platelets >50 x10(9)/L was 52.3 days (range 26-86 days). They survived in a disease-free state. Of the 9 children in the group infused with TNC between 10 x 10(7)/kg and 7 x 10(7)/kg, 7 got engraftment. The median time of absolute neutrophil count >0.5 x 10(9)/L was 16.4 days (range 11-30 days) and platelets >50 x 10(9)/L was 63.7 days (range 34-140 days). Four children got a long-term stable engraftment and survived in a disease-free state. Two children with beta-thalassemia major had secondary rejection after engraftment and autologous hematopoitic recovery. One child died after engraftment and one child died in the early period after transplantation. Of the 18 children in the group infused with TNC<7 x 10(7)/kg, 16 children got engraftment. The median time of absolute neutrophil count >0.5 x 10(9)/L was 19.5 days (range 10-29 days) and platelets >50 x 10(9)/L was 70.1 days (range 41-116 days). Eight children had a long-term stable engraftment and survived in a disease-free state. Two children with beta-thalassemia major had secondary rejection after engraftment and autologous hematopoitic recovery. Six children died after engraftment. Two children had graft failure. CONCLUSIONS: TNC dose is an important influencing factor for hematopoietic stem cell engraftment in cord blood transplantation. An increased TNC dose may improve the success of cord blood transplantation.

[Haploidentical hematopoietic stem cell transplantation for beta-thalassemia major in children].

OBJECTIVE: Hematopoietic stem cell transplantation is currently a unique curative therapy for beta-thalassemia major. However, only 30% of patients have HLA-identical siblings to serve as donors. This study investigated the feasibility of hematopoietic stem cell transplantation from HLA mismatched related donors for beta-thalassemia major in children. METHODS: Between November 2001 and November 2007, 10 patients with beta-thalassemia major at median ages of 4.4 years (range:1.6-9.4 years) received 11 transplantations from their haploidentical donors, either HLA mismatched sibling umbilical cord bloods (n=6) or parents marrows (n=4) or sibling marrow (n=1). The conditioning regiment included fludarabine (100 mg/m2), busulfan (16 mg/kg), cyclophosphamide (200 mg/kg) and antithymocyte globulin. RESULTS: Of the 10 patients, 6 (60%) had sustained engraftment and red blood cell transfusion independence; 2 patients showed transient engraftment but rejected the graft quickly; 1 patients had no evidence of engraftment and developed aplastic anemia; 1 patient who received two transplantations had no evidence of engraftment and developed persistent aplastic anemia. All eight engrafted patients showed grade I to III acute graft-versus-host disease (GVHD), and only one developed limited skin chronic GVHD. The probability of overall and disease-free survival was 90% and 60%, respectively, with a median follow-up duration of 57.1 months (range: 2.5 to 85.1 months). CONCLUSIONS: Haploidentical stem cell transplantation is an alternative option for children with beta-thalassemia major, particularly when a matched sibling donor is not available.

[Relationship between cellular immune function during conditioning and graft rejection in patients with beta-thalassemia major].

OBJECTIVE: To analyze the relationship between cell-mediated immune function during conditioning and graft rejection in patients with beta-thalassemia major. METHODS: Allogeneic hematopoietic stem cell transplantation was performed in 25 children with beta-thalassemia major and 11 with acute leukemia group. The percentages of T lymphocytes and natural killer (NK) cells in peripheral blood of these patients were detected with dual color immunofluorescence on day -10 (before conditioning) and day -5 (after conditioning), and the relationship between the cellular immune function and graft rejection was analyzed. RESULTS: All the patients with acute leukemia showed engraftment. The rate of graft rejection was 34.8% in the patients with beta-thalassemia major. Compared with the leukemic patients, the patients with beta-thalassemia showed significantly increased percentage of CD3(+)CD8(+) T lymphocytes before and after the conditioning (P<0.05). The percentage of CD3(-)CD56(+) NK cells increased significantly in patients with beta-thalassemia major after the conditioning (P<0.05), but decreased markedly after conditioning in the leukemic patients (P<0.05). In patients with beta-thalassemia major and graft rejection, the CD3(-)CD56(+) cell phenotype was predominant after conditioning but remained unchanged in those with engraftment. CONCLUSION: CD3(-)CD56(+) NK cells are probably associated with graft rejection in patients with beta-thalassemia major, and may serve as an index for predicting graft rejection following allogeneic hematopoietic stem cell transplantation.

[Relationship between growth disorders and iron overload in children with beta-thalassemia major].

OBJECTIVE: To study the status of growth and development and the relationship between growth disorders and iron overload in children with beta-thalassemia major. METHODS: Fifty children with beta-thalassemia major and who received blood transfusion therapy regularly (age: 9 months-17 years) were enrolled. They were subjected to a thorough history taking, clinical examinations, and laboratory examinations, including complete blood count, alanine transferasa (ALT) and serum ferritin. The physical growth parameters, such as height and weight, were compared with the reference values of Chinese children. RESULTS: Twenty-four patients (48%) were of short stature with height under the 3th percentile. Among them, 15 cases presented with their height and weight both under the 3th percentile. Spontaneous sex development was seen in 7 cases out of 21 over 10-year-old patients. No sex development was found in 4 out of 8 patients who were over 14 years old. The patients with a height under the 10th percentile (n=31) had higher serum ferritin levels (8239.2+/-5865.5 mg/L vs 5028.1+/-3885.7 mg/L; P<0.05) and lower hemoglobin levels (68.2+/-12.3 g/L vs 79.7+/-14.5 g/L; P<0.05) as well as hepatomegaly when compared with those patients with a height over the 10th percentile (n=19). Serum ferritin levels in 20 patients with a weight under the 10th percentile were significantly higher than those in 30 patients with a height over the 10th percentile (9165.5+/-6042.5 mg/L vs 5567.3+/-4447.3 mg/L; P<0.05). CONCLUSIONS: Short stature, low weight and sex development delay are common in children with beta-thalassemia major. This may be related to iron overload.

[Efficacy of low-dose heparin and prostaglandin E1 in the prevention of hepatic veno-occlusive disease after allogenic hematopoietic stem cell transplantation in children with beta-thalassemia major].

OBJECTIVE: Hepatic veno-occlusive disease (HVOD) is one of the most serious complications after allogenic hematopoietic stem cell transplantation (allo-SCT). Endothelial injury, leading to deposition of coagulation factors in the terminal hepatic venules, is believed to the key event in the pathogenesis of HVOD. This study was designed to explore the efficacy of low-dose heparin and prostaglandin E1 (PGE1) in the prevention of HVOD after allo-SCT in children with beta-thalassemia major. METHODS: Forty-three children with beta-thalassemia major received allo-SCT. For the prevention of HVOD, 23 of the 43 patients received low-dose heparin (100 IU/kg.d) and also received PGE1 (7.2 microg/kg x d) by continuous intravenous infusion (study group) from the beginning of conditioning treatment to the 30th day after allo-SCT. Patients who received continuous infusions of PGE1 (7.2 microg/kg x d) alone were used as the control group (n=20). RESULTS: HVOD occurred in 6 patients (26.1%) in the study group (3 mild, 3 moderate). Twelve patients in the control group had HVOD (60.0%) (3 mild, 3 moderate, 6 severe)(P < 0.05). In the study group, 5 cases of HVOD were treated successfully and one died from other complications. Of the 12 cases of HVOD in the control group, 10 patients were treated successfully and two patients died from HVOD. There were no obvious drug adverse effects in the two groups. CONCLUSIONS: Low-dose heparin and PGE1 is more effective than PGE1 alone for the prevention of HVOD after allo-SCT.

[Combined transplantation of umbilical cord blood and bone marrow from same sibling donor in children with beta-thalassemia major].

The objective of this study was to investigate the curative effect of combined sibling umbilical cord blood and bone marrow transplantation in treatment of beta-thalassemia major. Combined umbilical cord blood and bone marrow transplantation from an HLA-identical sibling were performed for 3 patients with beta-thalassemia major. The nucleated cells infused into 3 recipients were 19.5 x 10(7)/kg, 20.8 x 10(7)/kg and 23.3 x 10(7)/kg respectively. They accepted the conditioning regimen consisting of busulfan, cyclophosphamide, antithymocyteglobulin. The results showed that three patients gained protracted and stable engraftment. The time to achieve more than 0.5 x 10(9)/L neutrophils in three patients was 16, 18, and 17 days respectively; the time to achieve more than 50 x 10(9)/L platelet in three patients was 48, 50, and 49 days respectively. The speed of hematopoietic recovery was faster than that of umbilical cord blood transplantation (UCBT) only. Three patients all suffered from acute graft-versus-host disease (aGVHD) of I grade. They had lived with free-thalassemia for 1.5, 2.0 and 2.1 years respectively. Their Hb had been maintained at normal level without transfusion. It is concluded that combined UCBT and BMT may be an effective and safe way to treat pediatric beta-thalassemia major.

[Umbilical cord blood transplantation for patients with beta-thalassemia major].

OBJECTIVE: The beta-thalassemia major is a common hereditary hematology disease in southern China. The combination of blood transfusion and iron chelation is now the reference treatment. The allogeneic hematopoietic stem cell transplantation is the only curative therapy for beta-thalassemia major. In this study the investigators observed and evaluated the effects of umbilical cord blood transplantation (UCBT) for patients with beta-thalassemia major. METHODS: Twelve cases of beta-thalassemia major aged from 1.3 to 8.3 years (8 male and 4 female) received UCBT. Eleven of the twelve donors were siblings and one was unrelative. Eight patients received no antigen and four patients received two antigen disparate grafts. According to the Pesaro's classification for thalassemia, 10 patients were at grade I or II, and 2 were at grade III. The HLA-identical patients accepted the conditioning regimen consisting of busulfan, cyclophosphamide and antithymocyteglobulin. The HLA-mismatched patients accepted the conditioning regimen consisting of hypertransfusions, continuous iv desferrioxamine, hydroxyurea, fludarabine, busulfan, cyclophosphamide and antithymocyteglobulin. The harvest stem cells contained 3.63 - 16.0 x 10(7)/kg of nucleated cells, 0.11 - 1.03 x 10(6)/kg of CD(34)(+) cells and 0.17 - 1.18 x 10(5)/kg of colony-forming-unit-granulocyte macrophages. Cyclosporine alone or in combination with mycophenolate mofetil (MMF) was given for acute graft-versus-host disease (aGVHD) prophylaxis. RESULTS: Of the 12 patients, 10 were engrafted. Ten patients had neutrophil recovery (> 0.5 x 10(9)/L) and seven patients had platelet recovery (> 50 x 10(9)/L). The median time was 18.1 and 57.3 days, respectively. Seven patients had disease-free survival (DFS) at a median follow up of 23 months (range 4 - 63 months). Three patients had rejection and autologous hematopoitic reconstitution. Two patients were not engrafted. One patient acquired severe aplastic anemia, another patient died of severe infection. The incidences of grade I and grade II aGVHD were 60% (6/10) and 40% (4/10), respectively. There were no long-term complications in the disease free survivors. CONCLUSIONS: Grade I-II beta-thalassemia major patients receiving sibling UCBT had high DFS. UCBT is an effective way to treat beta-thalassemia major.

[Two HLA-loci mismatched sibling cord blood transplantation in a severe beta-thalassemia patient].

Allogeneic hematopoietic stem cell transplantation is the only curative therapy for severe beta-thalassemia. This time, the experience of utilizing HLA 2-loci mismatched sibling cord blood transplantation (CBT) in a child with severe beta-thalassemia was firstly reported in our country. A 3-year-male patient had been diagnosed with severe beta-thalassemia at 6 months of age (HbF 86.6%, HbA1 1.7%, HbA2 1.7%, beta globin gene mutation CD17, A-->T/IVS-II-654, C-->T). The patient's HLA typing was A 24,11, B 58,35 and DRB1 03,15. During a subsequent maternal pregnancy. The prenatal diagnosis for thalassemia and prenatal HLA typing analysis were performed on 18 weeks of pregnancy. The results indicated that the male fetus was a heterozygote (beta globin gene mutation N/CD17, A-->T), HLA typing was A 24,11, B 58,51 and DRB1 03,12. 120 ml cord blood was collected at time of delivery, the total numbers of nucleated cells, CFU-GM and CD34(+) cells were 1.830 x 10(9), 16.653 x 10(5) and 3.11 x 10(6), respectively. A new conditioning regimen including: hypertransfusion, continuous i.v. desferrioxamine, busulfan, cyclophosphamide, antithymocyte globulin plus hydroxyurea and fludarabine. GVHD prophylaxis comprised cyclosporin A and mycophenolate mofetil. The viability of cord blood at the time infusion was 92%, The total numbers of nucleated cells, CFU-GM and CD34(+) cells in the transfused cord blood were 12.06 x 10(7)/kg, 1.098 x 10(5)/kg, and 2.04 x 10(6)/kg, respectively. Results showed that the patient's clinical course after cord blood transplantation was unremarkable. Acute GVHD grade I developed on day 15, methylprednisolone 2 mg/kg was given to cure. Neutrophil engraftment (ANC > 0.5 x 10(9)/L) on day 17, platelet engraftment (> 50 x 10(9)/L) on day 50. The patients became independent from red blood cell transfusion since day 80 (when his hemoglobin level kept > 12.5 g/L). His beta globin gene mutation and HLA typing were all the same as the donor's analyzed on day 60 and 200. There was also a switch in blood group from A pre-transplant to O post-transplant. It is concluded that the new conditioning and GVHD prophylaxis regimens allow a successful engraftment in this case. This observation may contribute in developing UCBT as an alternative when matched sibling donors are not available.