Autologous peripheral blood stem cell transplantation with BCVAC conditioning in childhood acute myeloid leukemia

Radiologic evaluation of pulmonary injury following carmustine- and cyclophosphamide-based preparative regimen for autologous peripheral blood stem cell transplantation in children

BACKGROUND

Toxicity of carmustine and cyclophosphamide can cause pulmonary injury after hematopoietic stem cell transplantation.

OBJECTIVE

To evaluate the radiologic findings of pulmonary injuries following carmustine- and cyclophosphamide-based preparative regimens in children.

MATERIALS AND METHODS

From 2010 to 2014, 35 children received carmustine- and cyclophosphamide-based preparative regimens. Fourteen of 35 children presented with symptoms and radiologic abnormalities. Eight of 14 children had no evidence of infection, cardiogenic edema, or other explainable causes. We retrospectively analyzed their chest radiographs and CT scans for ground-glass opacity, consolidation, septal thickening and pleural effusion.

RESULTS

Major chest radiographic findings were bilateral diffuse ground-glass opacity (n=8) and septal thickening (n=7). CT findings were multifocal patchy (n=4) or inhomogeneously diffuse (n=4) ground-glass opacity, multifocal consolidations (n=7) and septal thickening (n=7). All of these lesions at CT were bilateral, but showed lower lobe predominance in 88, 100, and 63%, respectively. There was no central/peripheral or anterior/posterior predilection. Six children had small pleural effusions, which were bilateral in five children.

CONCLUSION

Bilateral ground-glass opacity with or without consolidation, septal thickening and pleural effusion were common radiologic findings in pulmonary injury following carmustine- and cyclophosphamide-based preparative regimens.

High-dose chemotherapy and autologous peripheral blood stem cell transplantation with BCVAC regimen followed by maintenance chemotherapy for children with very high risk acute lymphoblastic leukemia

Allogeneic hematopoietic stem cell transplantation (HSCT) is the recommended treatment for children with very high risk acute lymphoblastic leukemia (ALL), but it requires adequate institutional infrastructure, experience, and expertise, especially for alternative donor HSCT. We review our experience with high-dose chemotherapy (HDCT) and autologous peripheral blood stem cell transplantation (APBSCT), followed by post-APBSCT maintenance chemotherapy for children with very high risk ALL. Between August 1997 and November 2012, our institute was not successful with HLA-haploidentical HSCT. Thus, if patients lacked HLA-matched allogeneic donors or cord blood donors, we treated them with HDCT and APBSCT with carmustine, etoposide, cytarabine, and cyclophosphamide, followed by post-APBSCT maintenance chemotherapy with vincristine, oral prednisolone, methotrexate, and 6-mercaptopurine.Ten patients underwent HDCT and APBSCT due to relapse, biphenotype leukemia, Philadelphia translocation, MLL rearrangement, hypodiploidy, and initial white blood cell count above 20.0 × 109/L. At a median 7.4 years from HDCT to APBSCT, overall survival (OS) was 70.0% ± 14.5% and event-free survival (EFS) was 70.0% ± 14.5%. Adverse events were tolerable, without treatment-related mortality.This historical analysis may be a useful reference when allogeneic HSCT including alternative donor HSCT cannot be performed for children with very high risk ALL.

Effect of FOXP3 polymorphism on the clinical outcomes after allogeneic hematopoietic stem cell transplantation in pediatric acute leukemia patients

Forkhead BOX P3 (FOXP3) polymorphisms have recently been investigated as candidate risk factors in several tumors and autoimmune diseases. This study aims to evaluate the potential influence of FOXP3 rs3761548 polymorphism in the donor on the outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT). A total of 171 patients were enrolled for this study and genotyped using direct sequencing. Patients with rs3761548 CC genotype had higher incidence of hepatic veno-occlusive disease (HVOD) and cytomegalovirus (CMV) infection than that of the individuals with AA or AC genotype (P=0.011, P=0.023). Treatment-related mortality (TRM) rate of patients with AA or AC genotype was lower than that of the patients with CC genotype (P=0.044) resulting in a difference in overall survival (OS). However, there was no difference in graft-versus-host disease (GVHD) relapse or blood stream infection (BSI), depending on the genotype at rs3761548 locus. In multivariate analysis, CC genotype showed as a risk factor in the development of HVOD and CMV infection, with low OS. In conclusion, this is the first report on FOXP3 rs3761548 SNP in allo-HSCT and we suggest that this SNP be considered a candidate marker for predicting the development of HVOD and CMV infection after allo-HSCT.

Comparison of total body irradiation before and after chemotherapy in pretreatment for hematopoietic stem cell transplantation

OBJECTIVE

To explore the best time to carry out total body irradiation (TBI) in hematopoietic stem cell transplantation (HSCT) pretreatment.

METHODS

Retrospective analysis was applied in 88 cases of HSCT using TBI as pretreatment from March 2001 to June 2009 in our hospital. Using 8 MV X-ray, all the patients were irradiated by linear accelerator in 2 consecutive days, with a total dose of 7-11 Gy and an instantaneous dose rate ranging between 4.0 and 5.0 cGy/min. Of the 88 cases, 40 cases were given traditional high-dose chemotherapy before TBI (Group CT/TBI), and 48 cases were given TBI before chemotherapy (Group TBI/CT) instead.

RESULTS

Eighty-seven cases of transplantation were successful, with no serious complications, including radiation pneumonia. Compared with Group CT/TBI, Group TBI/CT showed similar incidence of complications (p=0.08), similar recent chemotherapy toxicity (p=0.833), and significantly lower recent radiation toxicity (p=0.000).

CONCLUSIONS

TBI in the pretreatment of HSCT is safe and effective. Using TBI before the high-dose chemotherapy can maintain the same pretreatment effect, effectively reduce apparent immediate reaction/discomfort during TBI, reduce preparation workload of radiotherapy, and lower radiation side-effects. Further research is needed to expand its clinical application.

Retroviral gene therapy for X-linked chronic granulomatous disease: results from phase I/II trial

X-linked chronic granulomatous disease (CGD) is an inherited immunodeficiency caused by a defect in the gp91(phox) gene. In an effort to treat X-CGD, we investigated the safety and efficacy of gene therapy using a retroviral vector, MT-gp91. Two X-CGD patients received autologous CD34(+) cells transduced with MT-gp91 after a conditioning regimen consisting of fludarabine and busulfan. The level of gene-marked cells was highest at day 21 (8.3 and 11.7% in peripheral blood cells) but decreased to 0.08 and 0.5%, respectively, 3 years after gene transfer. The level of functionally corrected cells, as determined by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase assay, reached a peak at day 17 (6.5% patient 1 (P1) and 14.3% patient 2 (P2) of total granulocytes) and declined to 0.05% (P1) and 0.21% (P2), 3 years later. Some retroviral vectors were found to have integrated within or close to the proto-oncogenes MDS1-EVI1, PRDM16, and CCND2; however, no abnormal cell expansion or related hematological malignancy was observed. Overall, the gene transfer procedure did not produce any serious adverse effects and was able to convert a significant fraction of blood cells to biologically functional cells, albeit for a short period of time.

High transcript level of FLT3 associated with high risk of relapse in pediatric acute myeloid leukemia

Identification of prognostic factors and risk-based post-remission therapy was proposed to improve the outcomes of acute myeloid leukemia (AML) and a mutation of FLT3 has been reported to be a risk factor, especially for pediatric patients. Recently, FLT3 expression level was implicated to have prognostic significance in adults, but little is known for childhood AML. To define the prognostic significance, transcript level of FLT3 was analyzed in 52 pediatric AML patients. The median copy number of FLT3 was 4.6x10(3) (40-5.9x10(7) copies)/1.0x10(6) GAPDH copy, and the relapse free survival of patients with high transcript level of FLT3 (>10(6) copy number) (0%) was significantly lower than that of the others (53.2%). High transcript level of FLT3 was associated with a markedly high risk of relapse. The development of new therapeutic scheme such as a frontline allogeneic stem cell transplantation or administration of FLT3 inhibitor is needed to improve outcomes.

Pulmonary function following total body irradiation (with or without lung shielding) and allogeneic peripheral blood stem cell transplant

Our purpose was to determine if total body irradiation (TBI) with lung dose reduction protects against subsequent radiation-induced deterioration in pulmonary function. Between July 1997 and August 2004, 181 consecutive patients with hematologic malignancies received fractionated TBI before allogeneic peripheral blood stem cell transplant. The first 89 patients were treated to a total dose of 13.6 Gy. Thereafter, total body dose was decreased to 12 Gy with lung dose reduction to 9 or 6 Gy. All patients underwent pulmonary function test evaluation before treatment, 90 days post-treatment, then annually. Median follow-up was 24.0 months. Eighty-nine patients were treated with lung shielding, and 92 without. At 1-year post transplant, there was a small but significant difference in lung volume measurements between patients with lung shielding and those without. This was not observed at the 2-year time point. When stratified by good (>100% predicted) or poor (</=100% predicted) baseline lung function, patients with poor function demonstrated protection at 1 year with lung shielding, while those with good initial lung function did not. TBI with or without lung dose reduction has a small but statistically significant effect on pulmonary function measured at 1 year but not 2 years post irradiation.

Efficacy of CD34+ stem cell dose in patients undergoing allogeneic peripheral blood stem cell transplantation after total body irradiation

We estimated the effect of CD34(+) stem cell dose during peripheral blood stem cell transplantation (PBSCT) in predicting mortality after total body irradiation (TBI). Between 1997 and 2004, 146 consecutive patients with hematologic malignancies received fractionated TBI (12-13.6 Gy) in 8 fractions over 4 days before undergoing PBSCT; 61 patients received TBI with reduced radiation dose to the lung (6-9 Gy). The number of CD34(+) cells transplanted was recorded for all patients. A cubic spline representation for CD34(+) dose within a Cox proportional hazards model was used to model the relationship between the CD34(+) dose and mortality. Median follow-up was 44 months (range, 12-90 months). The CD34(+) cell dose ranged from 2.45 to 15.90 x 10(6) cells/kg (median, 5.15 x 10(6) cells/kg). Risk of mortality decreased with CD34(+) doses between 4-8 x 10(6) cells/kg and then began to increase. For all patients, CD34(+) doses of 5.1-12.9 x 10(6)/kg resulted in at least a doubling of median survival associated with the lowest CD34(+) value. In patients treated with lung dose reduction, a similar range of CD34(+) dose (4.3-10.2 x 10(6) cells/kg) produced at least a 5-fold improvement from the survival associated with the lowest CD34(+) dose; however, the relationship between CD34(+) dose and mortality was not statistically different when analyzed by lung dose reduction. A method for assessing risk of mortality by CD34(+) dose as a continuous variable is presented. Risk of mortality decreased with CD34(+) doses between 4-8 x 10(6) cells/kg and then began to increase.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the therapy of acute myeloid leukemia in children: an evidence-based review

Clinical research examining the role of hematopoietic stem cell transplantation (SCT) in the therapy of acute myeloid leukemia (AML) in children is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are presented in the table entitled "Summary of Treatment Recommendations Made by the Expert Panel for Pediatric Acute Myeloid Leukemia" and were reached unanimously by a panel of experts in AML. The identified priority areas of needed future research in pediatric AML include: What is the role of risk group stratification, including the role of cytogenetics, in selection of patients for allogeneic SCT, especially those in first CR? What is the appropriate timing and use of alternative donor SCT, given that matched unrelated donor SCT appears to yield outcomes equivalent to matched related donor SCT? What is the role of reduced intensity SCT (including the use of fludarabine-based preparative regimens) and/or other immunomodulatory approaches to maximize the graft-versus-leukemic effect? and What is the role of biologically targeted agents (ie, tyrosine kinase inhibitors, farnesyl transferase inhibitors, Flt-3 inhibitors, etc) in the treatment of AML, including induction, consolidation, conditioning regimens, and after SCT?

Pretransplant pulmonary function tests predict risk of mortality following fractionated total body irradiation and allogeneic peripheral blood stem cell transplant

PURPOSE

To determine the value of pulmonary function tests (PFTs) done before peripheral blood stem cell transplant (PBSCT) in predicting mortality after total body irradiation (TBI) performed with or without dose reduction to the lung.

METHODS AND MATERIALS

From 1997 to 2004, 146 consecutive patients with hematologic malignancies received fractionated TBI before PBSCT. With regimen A (n=85), patients were treated without lung dose reduction to 13.6 gray (Gy). In regimen B (n=35), total body dose was decreased to 12 Gy (1.5 Gy twice per day for 4 days) and lung dose was limited to 9 Gy by use of lung shielding. In regimen C (n=26), lung dose was reduced to 6 Gy. All patients received PFTs before treatment, 90 days after treatment, and annually.

RESULTS

Median follow-up was 44 months (range, 12-90 months). Sixty-one patients had combined ventilation/diffusion capacity deficits defined as both a forced expiratory volume in the first second (FEV1) and a diffusion capacity of carbon dioxide (DLCO)<100% predicted. In this group, there was a 20% improvement in one-year overall survival with lung dose reduction (70 vs. 50%, log-rank test p=0.042).

CONCLUSION

Among those with combined ventilation/diffusion capacity deficits, lung dose reduction during TBI significantly improved survival.

Prognostic significance of FLT3 mutations in pediatric non-promyelocytic acute myeloid leukemia

FLT3 is a receptor tyrosine kinase involved in the survival of hematopoietic stem cells, and mutations of FLT3 have been reported to be of prognostic significance. This is the first study of FLT3 mutations in pediatric non-promyelocytic AML patients that received the same treatment scheme in single institute. FLT3 internal tandem duplication of the juxtamembrane domain (FLT3/ITD) and a point mutation in the tyrosine kinase domain (FLT3/TKD) were analyzed in 61 patients by PCR of genomic DNA. The incidence of FLT/ITD and FLT/TKD were 6.6% (4/61) and 3.3% (2/61), respectively. Patients with FLT3/TKD remain alive after autologous stem cell transplantation. The disease-free survival (DFS) of patients with FLT3/ITD (0%) was significantly lower than that of the others (52%). FLT3/ITD was the sole adverse prognostic factor for DFS by multivariate analysis (RR=5.6). Patients with FLT3/ITD relapsed early after complete remission even after receiving bone marrow transplantation from a matched related donor with little BuCy conditioning. New therapeutic scheme such as stem cell transplantation with more intensive conditioning just after complete remission could be applied in pediatric non-promyelocytic AML patients with the FLT3/ITD mutation.

Fludarabine, cyclophosphamide plus thymoglobulin conditioning regimen for unrelated bone marrow transplantation in severe aplastic anemia

Antithymocyte globulin (ATG) has been used in severe aplastic anemia (SAA) as a part of the conditioning regimen. Among the many kinds of ATG preparations, thymoglobulin had been found to be more effective in preventing GVHD and rejection of organ transplants. As the fludarabine-based conditioning regimens without total body irradiation have been reported to be promising for bone marrow transplantation (BMT) from alternative donors in SAA, thymoglobulin was added to fludarabine and cyclophosphamide conditioning to reduce GVHD and to allow good engraftment in unrelated BMT. Five patients underwent BMT with cyclophosphamide (50 mg/kg once daily i.v. on days -9, -8, -7 and -6), fludarabine (30 mg/m2 once daily i.v. on days -5, -4, -3 and -2) and thymoglobulin (2.5 mg/kg once daily i.v. on days -3, -2 and -1) from HLA-matched unrelated donors. Complete donor type hematologic recovery was achieved in all patients. No serious complication occurred during BMT. Only one patient developed grade I acute GVHD resolved spontaneously. Except for one who had rupture of hepatic adenoma 78 days after BMT, all the other four patients are still alive with median 566 days. Fludarabine, cyclophosphamide plus thymoglobulin conditioning allows for the promising results of good engraftment, tolerable toxicity and minimal GVHD.