Unrelated versus related allogeneic stem cell transplantation after reduced intensity conditioning

BACKGROUND: The use of reduced intensity conditioning (RIC) regimens in allogeneic hematopoietic stem cell transplantation (HSCT) has increased over the past five years. PATIENTS: In this study, involving 137 patients, we compared the outcome after RIC in patients receiving grafts from matched unrelated donors (MUD; n=74) and sibling donors (n=63). The MUD and sibling groups were comparable regarding diagnosis, including solid tumors and hematological malignancies, and conditioning regimens. RESULTS: Engraftment was successful in most patients (88%), with no significant difference between MUD and sibling transplants. Cytomegalovirus (CMV) infection was more common in the MUD group (65%) than in the sibling group (46%) (P=0.04). No difference in severe acute graft-versus-host disease (GVHD) was found between the groups. However, the incidence of chronic GVHD was higher after sibling transplants. This was probably due to higher donor age in this group, since this was the only significant risk factor for chronic GVHD in multivariate analysis. The incidence of transplant related mortality (TRM) was significantly higher after MUD transplantation (40%) than after sibling transplantation (16%) (P<0.01). Because relapse/disease progression was more common after sibling transplantation, there was no significant difference in overall survival between the two groups. CONCLUSION: Using unrelated donors after RIC is feasible, but it resulted in more CMV infection and increased transplant-related mortality. Survival was comparable to that of sibling transplants.     

Nonmyeloablative conditioning does not prevent telomere shortening after allogeneic stem cell transplantation

BACKGROUND: Stem cell transplantation (SCT) may be associated with premature aging of the hematopoietic stem cells. Telomere length reflects the proliferative history of a cell. In most studies published so far on telomere dynamics after myeloablative allogeneic SCT, recipients had shorter telomeres than their respective donors, thus reflecting "accelerated aging" of hematopoietic cells. We evaluated telomere dynamics in patients who underwent transplantation with nonmyeloablative protocols, assuming that the decreased intensity of chemotherapy might prevent telomere attrition. METHODS: Telomere length was measured using FISH-FACS method. Telomeres of recipients were compared to their respective donors. Twenty-three consecutive patients after nonmyeloablative SCT were evaluated. A control group consisted of 10 donor-recipient pairs after conventional myeloablative transplantation. RESULTS: There was significant telomere shortening in both recipients of nonmyeloablative and myeloablative conditioning (0.487+/-0.65 kb, P=0.003; 0.361+/-0.50 kb, P=0.047 respectively). The extent of telomere shortening in the two groups was not different (P=0.64). There was no correlation between the degree of shortening and parameters such as time interval from transplant, age of donor or recipient, and the number of infused cells. CONCLUSIONS: This is the first study on telomere dynamics after nonmyeloablative conditioning SCT. The study demonstrates significant shortening of telomeres in recipients in spite of decreased intensity conditioning. Results of this study suggest that the main mechanism following transplantation is the proliferative stress imposed upon the stem cells and not direct damage by cytotoxic drugs. The different kinetics of restoration of hematopoiesis and the probable ongoing process of graft-versus-leukemia in the bone marrow do not prevent the attrition of telomeric ends of chromosomes.     

B-cell concentration in the apheretic product predicts acute graft-versus-host disease and treatment-related mortality of allogeneic peripheral blood stem cell transplantation

BACKGROUND: The influence of the graft composition on the clinical outcome after allogeneic peripheral blood stem cell (PBSC) transplantation is not well established. METHODS: The cellular composition of the apheretic products obtained from 63 human leukocyte antigen-identical siblings was prospectively correlated with the outcome of patients with hematological malignancies undergoing an allogeneic PBSC transplant after myeloablative conditioning. The concentration of nuclear, mononuclear, CD34+, T-cell subsets, B cells, and natural killer cells in the graft has been analyzed. RESULTS: In univariate analysis, acute graft-versus-host disease (GVHD) correlated with the disease (P=0.002), with the phase of disease at transplant (P=0.01), and with the number of CD20+ cells infused (P=0.05). In multivariate analysis, a dose of CD20+ cells in the graft higher than the median dose remained the only factor negatively affecting the incidence of acute GVHD (P=0.01; 95% confidence interval [CI]: 0.12-0.78). In univariate analysis, treatment-related mortality (TRM) correlated with the disease (P=0.04) and was negatively affected by a dose of infused B cells greater than the median value (28% versus 50%; P=0.02). In multivariate analysis, TRM was close to statistical correlation with the dose of CD20+ cells (P=0.06; 95% CI: 0.02-1.05). No other clinical parameter was influenced by the composition of the graft. CONCLUSIONS: Our results suggest that the concentration of B cells in the apheretic product may predict the incidence of acute GVHD and TRM in patients undergoing an allogeneic PBSC transplantation and open the way to the new preventive and therapeutic strategies for the management of GVHD.     

Molecular monitoring of T-cell chimerism early after allogeneic stem cell transplantation may predict the occurrence of acute GVHD grades II-IV

Mixed chimerism (MC) within CD4+ and CD8+ T cell days 7 and 10 after allogeneic stem cell transplantation (SCT) was compared with the occurrence of acute graft-vs.-host disease (GVHD) in 34 patients after SCT. Acute GVHD was diagnosed in 22 patients within the first 3 months after SCT, 15 of these developed acute GVHD grades II-IV. The difference in the clearance rate of host T cell between the two days were compared. We found a significantly higher risk (p = 0.005) for developing acute GVHD grades II-IV in patients with complete donor CD4+ T-cell chimerism day 7 after SCT together with patients who increased 50% or more in donor CD4+ T cells between days 7 and 10 after SCT. Our data suggest that molecular monitoring of MC early after transplantation may be useful as a diagnostic tool in predicting the occurrence of moderate to severe acute GVHD after SCT.     

Graft-versus-host Disease–free,Relapse-free Survival After HLA-identical Sibling Peripheral Blood Stem Cell Transplantation With Tacrolimus-based Graft-versus-host Disease Prophylaxis in Japanese Patients

The ideal post-allogeneic hematopoietic cell transplantation recovery is not just the cure of hematologic malignancies but also freedom from ongoing morbidity. Recent studies have revealed that HLA-identical sibling peripheral blood stem cell transplantation (PBSCT) had been providing impaired graft-versus-host disease (GVHD)–free relapse-free survival (GRFS) due to a higher risk of GVHD. Study on GVHD prophylaxis bears clinical reliance when focused on Japanese population because risk of GVHD differs among races. We identified 15 consecutive Japanese patients who received tacrolimus-based GVHD prophylaxis after myeloablative HLA-identical sibling PBSCT. No episode of grade ≥ II acute GVHD and only one episode of grade III toxicity were documented, with the control of mean weekly blood tacrolimus concentrations during the first 4 weeks at 13 to 17 ng/mL. An estimated 46.7% (95% CI: 21.4% to 71.9%) of the patients enjoyed their GRFS at 3 years after transplantation, and failure in the treatment of chronic GVHD was not reported during the median follow-up period of 1059 days (range, 784 to 1778 days) after the development of chronic GVHD. The results suggest that the application of tacrolimus with the optimization of its blood concentrations may effectively prevent ongoing morbidities after HLA-identical sibling PBSCT.     

造血干细胞移植治疗儿童髓系白血病26例疗效分析

目的 了解造血干细胞移植对儿童急性髓系白血病(AML)和慢性粒细胞白血病(CML)的治疗效果.方法 髓系白血病患儿26例,平均年龄为9.8岁,其中CML 8例,AML18例.CML患儿中,第1次慢性期(CPl)6例,加速期(AP)1例,第2次慢性期(CP2)1例;AML患儿中,第1次缓解(CRl)9例,第2次缓解(CR2)7例,2例未缓解(NCR).26例中,2例接受HLA全相合同胞供者的外周血与骨髓干细胞联合移植;2例接受由HLA半相合母亲供者外周血干细胞分离出的CD34+细胞输注;2例接受脐血移植;其余20例接受外周血造血干细胞移植.每例移植有核细胞(6.8±6.0)×108/kg,CD34+细胞(4.0±5.8)×106/kg,CD3+细胞(2.6±3.8)×108/kg.所有患儿均采用白消安及环磷酰胺进行清髓性预处理.移植后采用环孢素A和甲氨蝶呤联用预防移植物抗宿主病(GVHD),接受无关供者造血干细胞移植者加用抗胸腺细胞球蛋白,6例CML患儿加用霉酚酸酯.若发生Ⅱ度以上GVHD,则给予甲泼尼龙或巴利昔单抗治疗.结果 除2例HLA半相合移植失败外,其余24例均获得造血功能重建.24例植入成功的患儿中,2例未发生急性GVHD(aGVHD),15例(62.5%,15/24)出现Ⅰ～Ⅱ度aGVHD,7例(29.2%,7/24)出现Ⅲ～Ⅳ度aGVHD(重度aGVHD).7例重度aGVHD均为CML患儿.26例平均随访20.5个月,其中原发病复发死亡者4例,治疗相关死亡者5例,尚有17例(65.4%,17/26)患儿无病存活.结论 异基因造血干细胞移植有助于提高髓系白血病患儿的存活率,只要加强预防,无关供者造血干细胞移植产生的GVHD是可以控制的.而对于高危患儿,无关供者造血干细胞移植的效果与亲缘相关供者移植相似.     

Haploidentical Stem Cell Transplantation for Acute Leukemia Patients Who Experienced Early Relapse Within One Year After the First Transplantation

To assess the safety and efficacy of allogeneic stem cell transplantation from haploidentical related donors (haplo-SCT) as 2nd transplantation for patients with early relapsed disease, we retrospectively evaluated 7 consecutive patients (median age, 42 years; range, 29–63 years) who experienced relapse within 1 year of the 1st transplantation and received haplo-SCT as a 2nd transplantation. Among the 7 patients who received haplo-SCT, 2 who were in morphologically complete remission (CR) at transplantation were conditioned with a reduced-intensity regimen, and the 5 non-CR patients were conditioned with a myeloablative regimen. Both conditioning regimens included antithymocyte globulin. Graft-versus-host disease (GVHD) prophylaxis consisted of tacrolimus and methylprednisolone. Sustained neutrophil engraftment was achieved in all 7 patients. One patient developed severe acute GVHD. Notably, only 1 patient experienced relapse, and each patient achieved longer CR duration than after the 1st transplantation. Three of the 7 patients died from treatment-related causes: acute GVHD, post-transplantation lymphoproliferative disorder, and bacterial pneumonia. At the time of analysis, the 2-year overall survival rate of these 7 patients was 42.9%. This suggests that use of haploidentical related donors is a viable alternative for 2nd transplantation and should be confirmed in larger cohorts.     

Long-term follow-up of peripheral blood stem cell transplantation from mismatched related and unrelated donors

Allogeneic stem cell transplantation (SCT) is best performed with an HLA-identical sibling donor (matched related donor, MRD) to reduce the risk of early complications such as acute graft-vs.-host disease (aGvHD). However, as only about 30% of recipients have an MRD for this potentially curative approach, the use of family donors with one or two mismatches in the HLA-antigens (mismatch related donor, MMRD) or fully matched unrelated donors (MUD) ('alternative donors') has been introduced in the allogeneic SCT setting in recent years. To evaluate the feasibility of allogeneic SCT from alternative donors by using peripheral blood stem cells (PBSC) we initiated a prospective, phase II study in 1996. From April 1996 to July 1998, 18 patients with various hematological malignancies underwent allogeneic SCT from alternative donors (two patients with MUD and 16 patients with MMRD). All patients received stable engraftment and none of the patients had graft rejection. The rate of aGvHD (grades II-IV) and the relapse rate at last follow-up (seven to nine yr after SCT) were with 40% and 24%, respectively, comparable with those found in patients receiving allogeneic SCT from MRD. However, five yr after allogeneic SCT only 17% were alive, which was mainly due to the treatment-related mortality (TRM) rate of 59%. We conclude that allogeneic PBSC transplantation by using alternative donors is associated with an unsatisfying long-term TRM rate. The significance of TRM and particular late deaths has to be evaluated further in this transplantation setting.     

Myeloablative allogeneic hematopoietic stem cell transplantation in elderly patients

This study aimed to evaluate the outcome following myeloablative allogeneic hematopoietic stem cell transplantation (SCT) among patients older than 50 yr of age. A total of 215 patients with a median age of 57 yr underwent allogeneic hematopoietic SCT for early (41%) or advanced (59%) hematologic malignancies. After a median follow-up of 36 months a 10-yr survival estimate of 56 +/- 6% could be assessed for patients in early disease stages while patients with advanced diseases showed a significantly decreased survival probability of 31 +/- 5% (p < 0.0002). Transplant related mortality (TRM) at day 100 and 365 post-transplant was 13% and 30% for early but increased to 21% and 49% for advanced disease stages. As major determinants of TRM advanced disease stage (p < 0.0001) and occurrence of grades II-IV graft-vs.-host disease (GVHD) (p < 0.0001) were identified. These results show that hematopoietic SCT following myeloablative conditioning is also applicable to elderly patients whereas disease stage and high-grade GVHD represent the essential prognostic factors for outcome.     

Hematopoietic cell transplant outcomes after myeloablative conditioning with fludarabine,busulfan, low-dose total body irradiation,and rabbit antithymocyte globulin

Optimal conditioning and graft-vs-host disease (GVHD) prophylaxis for hematopoietic cell transplantation (HCT) are unknown. Here, we report on outcomes after low toxicity, myeloablative conditioning consisting of fludarabine, busulfan, and 4 Gy total body irradiation, in combination with thymoglobulin and post-transplant methotrexate and cyclosporine. We retrospectively studied 700 patients with hematologic malignancies who received blood stem cells from 7 to 8/8 HLA-matched unrelated or related donors. Median follow-up of surviving patients was 5 years. At 5 years, overall survival (OS), relapse-free survival (RFS), and chronic GVHD/relapse-free survival (cGRFS) were 58%, 55%, and 40%. Risk factors for poor OS, RFS, and cGRFS were (1). high to very high disease risk index (DRI), (2). high recipient age, and (3). cytomegalovirus (CMV)-seropositive recipient with seronegative donor (D−R+). The latter risk factor applied particularly to patients with lymphoid malignancies. Neither donor other than HLA-matched sibling (7-8/8 unrelated) nor one HLA allele mismatch was risk factors for poor OS, RFS, or cGRFS. In conclusion, the above regimen results in excellent long-term outcomes. The outcomes are negatively impacted by older age, high or very high DRI, and CMV D−R+ serostatus, but not by donor unrelatedness or one HLA allele mismatch.