Allogeneic bone marrow transplantation for chronic myeloid leukemia: a retrospective study of busulfan-cytoxan versus total body irradiation-cytoxan as preparative regimen in Koreans

Comparison of target volume and clinical effects of four radiotherapy plans for acute lymphoblastic leukemia prior to hematopoietic stem cell transplantation

The present study aimed to investigate the variations in target volume, clinical reaction and transplantation effects of helical tomotherapy (HT)-total body irradiation (TBI), HT-total marrow and lymphatic irradiation (TMLI), intensity modulated radiotherapy (IMRT)-TBI and IMRT-TMLI within patients with acute lymphoblastic leukemia (ALL). A total of 18 patients with ALL were treated with the four aforementioned radiotherapy plans prior to hematopoietic stem cell transplantation. A planned prescribed dose of 12 Gy/6 Frequency was administered to determine planning target volume (PTV). Dosimetry evaluation indexes in PTV and organs at risk were analyzed. Comparison of clinical untoward effects and the results of transplantation among the four plans were performed. The conformity index of HT plans was significantly increased compared with those in IMRT plans. The mean dose (D) to the lung and volume ratio of target volume occupied by 5 Gy (V₅) in TMLI plans were lower compared with TBI plans. Doses to organs were controlled within the normal range. D_max, D_mean and V₅ of bilateral lungs and D_max and D_mean of bilateral crystalline lens in IMRT plans were significantly higher compared with HT plans. There were no significant differences in untoward effects among the four plans. Subsequent to symptomatic treatments with antiemetic, antidiarrheal and fluid infusion, untoward effects improved, and all patients demonstrated tolerance to these therapies. A total of six patients treated with HT-TBI revealed complete and successful transplantation; however, one patient following transplantation suffered from severe rejection and had succumbed to mortality due to severe infection. Patients treated with HT-TMLI, IMRT-TBI and IMRT-TMLI completed successful transplantation and no rejection responses were observed. Conformity of HT plans are higher than that of IMRT plans. The four radiotherapy plans exhibit similar clinical untoward effects and the same transplantation success rate. HT-TMLI is more feasible in dosimetry compared with HT-TBI, IMRT-TBI and IMRT-TMLI, which require further long-term observation.

[Study of biological markers for radiation pretreatment of hematopoietic stem cell transplant recipients]

OBJECTIVE

To study the early biological parameter changes of blood and immune systems of mice after 60Co γ-ray irradiation in order to find sensitive and reliable biological dose markers for radiation pretreatment of hematopoietic stem cell transplant recipients.

METHODS

Pure strain BALB/c male mice were randomly divided into control group and three irradiation groups and absorbed doses of total body irradiation by ⁶⁰Co γ-ray were 0, 2, 4, 6 Gy, respectively. In 24h after irradiation, WBC counts and lymphocyte percentages of peripheral blood were determined by blood cell counting; polychromatic erythrocyte micronucleus（mn- PCE） of peripheral blood and bone marrow were observed by microscope after Giemsa staining; apoptosis rates of bone marrow, spleen, thymus cells were assayed by flow cytometry using Annexin Ⅴ and PI double staining.

RESULTS

Compared with the control group, WBC counts and lymphocyte percentages of peripheral blood in the irradiated groups significantly decreased with the increase of radiation doses（P<0.01），and their regression equations were E=0.1750D2-1.7440D+5.2020 and E=84.9390-3.4255D respectively. The mn-PCE of peripheral blood and bone marrow in the irradiated groups significantly increased with the increase of radiation doses（P<0.01）, bone marrow mn-PCE was positively correlated with the radiation dose with regression equation as E=3.9725D+2.9700. The early apoptosis rates of bone marrow cells, spleen and thymus cells significantly increased with the increase of radiation doses（P<0.01）, which were positively correlated with radiation doses, and their regression equations were E=3.42D + 8.36, E=3.0645D + 3.1840 and E=2.5620D + 2.5090 respectively.

CONCLUSION

Peripheral blood lymphocyte count and bone marrow mn-PCE rate were linearly correlated to radiation doses, which could be used as sensitive and reliable early biological markers of the radiation pretreatment recipients, and the doses of the radiation pretreatment recipients could be accurately judged according to their regression equations. The early apoptosis rates of bone marrow, spleen and thymus cells were positive linear correlation with the radiation doses, and their regression equations could be used to judge the degree of inhibition of the immune system for radiation pretreatment recipients.

[Total body irradiation: present and future]

Total body irradiation (TBI) has an established role as preparative regimen for bone-marrow transplantation in the treatment of hematological malignancies. Many randomized trials demonstrated that the clinical outcomes obtained from the association of TBI and cyclophosphamide are equivalent, or, sometimes, better than those based on chemotherapeutic agents. Despite the therapeutic progress of the last years, and the consequent improvement in the overall survival, this preparative regimen remains always associated with a relatively high rate of acute and late toxicity. In this article, we review the actual indications of TBI in clinical practice, and analyze the technological progress in this domain. We focus on the hypothesis that a selective irradiation of the hematopoietic or lymphoid organs is actually possible with intensity-modulated radiotherapy. Technical limits and preliminary results in terms of acute and late toxicities of intensity-modulated TBI are analyzed. With these new technologies, treatment-related toxicity is not anymore a major limiting factor in the preparative regimens for bone-marrow transplantation, allowing for a larger spectrum of TBI indications, a possible extension to patients older than 50 years, or a dose escalation. Preliminary results warrant, however, further evaluation in clinical trials to better assess the impact of this new approach on disease control and the long-term toxicity.

Allogeneic stem cell transplantation for patients with advanced hematological malignancies: comparison of fludarabine-based reduced intensity conditioning versus myeloablative conditioning

We compared the outcomes of allogeneic hematopoietic stem cell transplantation using reduced intensity and myeloablative conditioning for the treatment of patients with advanced hematological malignancies. A total of 75 adult patients received transplants from human leukocyte antigen-matched donors, coupled with either reduced intensity (n=40; fludarabine/melphalan, 28; fludarabine/cyclophosphamide, 12) or myeloablative conditioning (n=35, busufan/cyclophosphamide). The patients receiving reduced intensity conditioning were elderly, or exhibited contraindications for myeloablative conditioning. Neutrophil and platelet engraftment occurred more rapidly in the reduced intensity group (median, 9 days vs. 18 days in the myeloablative group, p<0.0001; median 12 days vs. 22 days in the myeloablative group, p=0.0001, respectively). Acute graft-versus-host disease (>or=grade II) occurred at comparable frequencies in both groups, while the incidence of hepatic veno-occlusive disease was lower in the reduced intensity group (3% vs. 20% in the myeloablative group, p=0.02). The overall 1-yr survival rates of the reduced intensity and myeloablative group patients were 44% and 15%, respectively (p=0.16). The results of present study indicate that patients with advanced hematological malignancies, even the elderly and those with major organ dysfunctions, might benefit from reduced intensity transplantation.

Glutathione S-transferase A1 polymorphisms and acute graft-vs.-host disease in HLA-matched sibling allogeneic hematopoietic stem cell transplantation

Busulfan and the metabolites of cyclophosphamide are conjugated with glutathione and catabolized by enzymes of the cytosolic glutathione S-transferases family. There are clearly linked single nucleotide polymorphisms in the promoter region of the glutathione S-transferase A1 gene (i.e., GSTA1*A, -567T, -69C and -52G; GSTA1*B, -567G, -69T and -52A). We assessed whether the clinical outcomes, including acute graft-vs.-host disease, of 61 patients with hematological malignancies, following HLA-matched sibling allogeneic stem cell transplantation using busulfan/cyclophosphamide conditioning are altered by glutathione S-transferase A1 genotypes. Globally, grade II-IV acute graft-vs.-host disease developed in 13 patients (21%). Grade II-IV acute graft-vs.-host disease developed in 15.2% of 46 patients with GSTA1*A/*A diplotype and in 40.0% of 15 patients with GSTA1*A/*B or GSTA1*B/*B diplotype (p = 0.04). Moreover, this relationship between GSTA1*A/*A diplotypes and lower incidence of acute graft-vs.-host disease was independent of the age, gender, stem cell source, and disease status. The incidences of acute skin graft-vs.-host disease were 7% (3/46) in patients with GSTA1*A/*A and 27% (4/15) in patients without GSTA1*A/*A (p = 0.009, univariate; p = 0.01, multivariate). Acute hepatic graft-vs.-host disease developed in 6 (13%) of 46 patients with the GSTA1*A/*A diplotype and in 4 (27%) of 15 patients without this diplotype (p = 0.09, univariate; p = 0.12, multivariate). Ten patients (16%) developed hepatic veno-occlusive disease. No significant difference was found in the incidence of hepatic veno-occlusive disease between patients with and without the GSTA1*A/*A diplotype (19.6% vs. 6.7%; p = 0.24). We conclude that the GSTA1*A/*A diplotype is an independent protective factor against acute graft-vs.-host disease, especially for skin graft-vs.-host disease, and probably for hepatic graft-vs.-host disease, in patients using busulfan/cyclophosphamide conditioning. The identification of glutathione S-transferase A1 genotypes prior to allogeneic stem cell transplantation could allow conditioning regimens and graft-vs.-host disease prophylaxis to be modified to improve outcome.

Pediatric live-donor kidney transplantation in Mansoura Urology & Nephrology Center: a 28-year perspective

Our objective was to evaluate our overall experience in pediatric renal transplantation. Between March 1976 and March 2004, 1,600 live-donor kidney transplantations were carried out in our center; 216 of the patients were 18 years old or younger (mean age 12.9 years). There were 136 male patients and 80 female patients. The commonest causes of end-stage renal disease (ESRD) were renal dysplasia (22%), nephrotic syndrome (20%), hereditary nephritis (16%), and obstructive uropathy (16%). Of the donors, 94% were one-haplotype matched and the rest were identical. Pre-emptive transplantation was performed in 51 (23%) patients. Triple-therapy immunosuppression (prednisone + cyclosporine + azathioprine) was used in 78.2% of transplants. Rejection-free recipients constituted 47.7%. Hypertension (62%) was the commonest complication. A substantial proportion of patients (48%) were short, with height standard deviation score (SDS) less than -1.88. The overall infection rate was high, and the majority (53%) of infections were bacterial. The graft survival at 1 year, 5 years and 10 years were 93.4%, 73.3% and 48.2%, respectively, while the patients' survival at 1, 5 and 10 years were 97.6%, 87.8% and 75.3%, respectively. Despite long-term success results of pediatric renal transplantation in a developing country, there is a risk of significant morbidity.

Comparative outcomes of reduced intensity and myeloablative allogeneic hematopoietic stem cell transplantation in patients under 50 with hematologic malignancies

We have conducted a direct comparison of the outcomes of reduced intensity and myeloablative conditioning in younger adults with hematological malignancies<50 yr. One hundred and five patients received transplants from human leukocyte antigen (HLA)-matched donors, via either reduced intensity (n=35) or myeloablative conditioning (n=70). The median ages of the reduced intensity and myeloablative groups were 36 and 33 yr (p=0.014). Neutrophil engraftment (i.e. time to absolute neutrophil count>0.5x10(9)/L) occurred more rapidly in the reduced intensity group (median: 10 d; range: 0-21 d) than in the myeloablative group (median: 18 d; range: 11-38 d; p<0.0001). The incidence of grades 2-4 acute graft-vs.-host disease were similar between the reduced intensity and myeloablative groups, at 17% vs. 24% respectively (p=0.40). The cumulative incidence of day 100 non-relapse mortality was 18% in the reduced intensity group, and 21% in the myeloablative group (p=0.88). The overall two-yr survival rates were 43% in the reduced intensity group, and 35% in the myeloablative group (p=0.72). In conclusion, reduced intensity transplantation yielded outcomes comparable with those of myeloablative transplantation in patients under 50 with hematological malignancies.

Busulfan-cyclophosphamide versus total body irradiation–cyclophosphamide as preparative regimen before allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia: What have we learned?

Most of the preparative regimens before allogeneic bone marrow transplantation include cyclophosphamide (Cy) with either busulfan (Bu) or total body irradiation (TBI). The Bu-Cy regimen has shown an advantage in chronic myeloid leukemia and TBI-Cy remains the standard conditioning regimen in acute lymphoblastic leukemia, but results are more conflicting in acute myeloid leukemia (AML). We report here the results of the most important studies comparing these two preparative regimens in AML. Survival is superior in all studies for patients treated with TBI and reached statistical significance in one of four trials. Two of three trials show significantly reduced transplant mortality and leukemia relapse. Higher incidences of veno-occlusive disease and hemorrhagic cystitis are reported with Bu. However, our long-term follow-up is limited, and to date no definitive conclusion can be drawn regarding late side effects. New approaches aiming at minimizing the toxicity without impairing the efficacy, such as targeted Bu plasma levels and nonmyeloablative conditioning regimens, seem promising but need to be evaluated further in future prospective studies.

Allogeneic hematopoietic stem cell transplantation for myeloproliferative disorders and myelodysplastic syndromes

Allogeneic SCT is the most effective method to achieve cure in patients with MPD and MDS. This approach is associated with significant risk of morbidity (eg, GVHD) and TRM, although the incidence and severity vary based on donor and recipient characteristics. For young patients with HLA-matched donors, SCT is the preferred therapy. Efforts to improve outcome for older patients and for patients with alternative donors have led to decreased treatment-associated complications with associated better long-term DFS.