Patients with acute lymphoblastic leukaemia allografted with a matched unrelated donor may have a lower survival with a peripheral blood stem cell graft compared to bone marrow

Benefits of plerixafor for mobilization of peripheral blood stem cells prior to autologous transplantation: a dual-center retrospective cohort study

BACKGROUND AIMS

Before autologous stem cell transplantation (ASCT), hematopoietic stem cells must be stimulated to move from the bone marrow to the peripheral blood for harvesting. Plerixafor, a C-X-C chemokine receptor type 4 antagonist, is used to increase stem cell harvests. However, the effects of plerixafor on post-ASCT outcomes remain unclear.

METHODS

In a dual-center retrospective cohort study of 43 Japanese patients who received ASCT, the authors compared transplantation outcomes in patients who underwent stem cell mobilization with granulocyte colony-stimulating factor with (n = 25) or without (n = 18) plerixafor.

RESULTS

The number of days to neutrophil and platelet engraftment was significantly shorter with plerixafor than without plerixafor, as assessed by univariate (neutrophil, P = 0.004, platelet, P = 0.002), subgroup, propensity score matching and inverse probability weighting analyses. Although the cumulative incidence of fever was comparable with or without plerixafor (P = 0.31), that of sepsis was significantly lower with plerixafor than without (P < 0.01). Thus, the present data indicate that plerixafor leads to earlier neutrophil and platelet engraftment and a reduction of infectious risk.

CONCLUSIONS

The authors conclude that plerixafor may be safe to use and that it reduces the risk of infection in patients with a low CD34+ cell count the day before apheresis.

A Single-Center Experience With Hematopoietic Stem Cell Transplantation for Pediatric Acute Lymphoblastic Leukemia: A Modest Pitch for Non-Total Body Irradiation Conditioning Regimens

OBJECTIVES

Allogeneic hematopoietic stem cell transplantation has been used for several decades to treat patients with acute lymphoblastic leukemia. Total body irradiation has been promoted as an important component of conditioning regimens for this process; however, recent reports of chemotherapy-based conditioning regimens have shown comparable outcomes.

MATERIALS AND METHODS

We report our experience with radiation-free conditioning using busulfan and cyclophosphamide in 127 pediatric patients with acute lymphoblastic leukemia who were treated between 1997 and 2014. The median age was 11 years (range, < 1 to 15 y), 70% of patients were male, 81.1% received transplants from HLA-matched siblings, 83% received peripheral blood stem cells, 41% were in second complete remission at the time of transplant, and 83% had B-lineage immunophenotype.

RESULTS

In patients who were in complete remission at the time of transplant, 5-year overall survival, leukemia-free survival, and relapse rates were 62.48% (95% confidence interval, 52.29-71.09%), 49.43% (95% confidence interval, 39.57-58.53%), and 45.64% (95% confidence interval, 35.85-54.88%), respectively. We observed significant differences between outcomes in patients by time of transplant, presence of chronic graft-versus-host disease, and remission status.

CONCLUSIONS

Our relapse rates were comparable to those shown in recent studies, although the transplant-related mortality rate was lower. The results of our study showed that a busulfan/cyclophosphamide conditioning regimen has acceptable outcomes without the undesirable adverse effects of total body irradiation, particularly in pediatric patients. Large multicenter studies are needed to assess less toxic conditioning regimens with fewer adverse effects in these patients.

An investigation on the predominant diseases, its diagnosis, and commonly used drugs in the poultry farms in the North-Eastern regions of Algeria

Aim

An investigation was carried out to assess the occurrence of diseases, its method of diagnosis, and commonly used drugs in poultry farms in North-Eastern regions of Algeria.

Materials and Methods

A total of 265 veterinary doctors were surveyed to obtain information on the dominant diseases, its frequency of occurrence, method of diagnosis, and commonly used drugs in poultry farms.

Results

A study revealed that about 68% of bacterial diseases are due to colibacillosis, mycoplasmosis, and salmonellosis, 22% of viral diseases are due to Newcastle, Gumboro, and infectious bronchitis, and 10% others including coccidiosis and ascites syndrome. The study also showed that about 57% of cases were diagnosed by clinical signs, 36% by necropsy findings, and the remaining 7% through therapeutic and laboratory analysis. Antibiotics, a predominance of the anarchic veterinary drugs, were massively used to control the diseases. Hence, there is a need for strict regulations on the use of veterinary drugs to guarantee food safety.

Conclusion

These results remain non-exhaustive but contribute strongly to determine the status of health of the birds in the region.

Optimal graft source for allogeneic hematopoietic stem cell transplant: bone marrow or peripheral blood?

Peripheral blood (PB), compared with bone marrow graft, has higher stem cell content, leads to faster engraftment and is more convenient for collection. Consequently, the use of PB graft has significantly increased in recent years. Although the use of PB graft is acceptable or even preferred to bone marrow graft in matched related donor allogeneic transplant due to a possibility of improved survival, PB graft increases the risk of chronic graft-versus-host disease and associated long-term toxicities in the setting of matched unrelated donor allogeneic transplant. In haploidentical transplant, mitigation of graft-versus-host disease with the use of post-transplant cyclophosphamide is a hypothesis-generating possibility; however, available studies have significant limitations to draw any definite conclusion.

Similar outcomes of peripheral blood stem cells vs. bone marrow for human leukocyte antigen-matched unrelated donor transplantation in adult patients with acute myeloid leukemia using risk-adapted graft-versus-host disease prophylaxis

BACKGROUND

In unrelated donor allogeneic stem cell transplantation (URD-SCT), most studies reported that peripheral blood stem cells (PBSC) resulted in higher incidence of acute and/or chronic graft-versus-host disease (GVHD) without survival benefits compared with bone marrow (BM). To overcome these shortcomings of PBSC, we have used a risk-adapted GVHD prophylaxis for patients that received HLA-matched URD-SCT, which was adding low-dose rabbit antithymocyte globulin (Thymoglobulin(®) , 1.25 mg/kg for 2 d) to conditioning in the transplants with PBSC and not BM.

METHODS

To determine whether this strategy is effective, we analyzed 115 adult patients with acute myeloid leukemia who received HLA-matched URD-SCT with PBSC (n = 70) or BM (n = 45) using our risk-adapted GVHD prophylaxis strategy.

RESULTS

The PBSC group showed faster neutrophil (11 d vs. 13 d; P < 0.01) and platelet (12 d vs. 18 d; P < 0.01) engraftment compared with the BM group. No difference was observed in the incidence of acute GVHD grade II-IV at 100 d (54.3% vs. 64.4%; P = 0.38) and chronic GVHD at 4 yr (65.1% vs. 60.0%; P = 0.83). Other outcomes including the incidence of relapse (30.8% vs. 31.2%; P = 0.53), non-relapse mortality (13.5% vs. 6.9%; P = 0.24), disease-free survival (55.7% vs. 61.9%; P = 0.68), and overall survival (62.2% vs. 63.2%; P = 0.96) at 4 yr were not significantly different.

CONCLUSION

Our risk-adapted GVHD prophylaxis strategy resulted in similar transplant outcomes including comparable incidence of GVHD between the PBSC and BM groups in HLA-matched URD-SCT.

PBSCT is associated with poorer survival and increased chronic GvHD than BMT in Japanese paediatric patients with acute leukaemia and an HLA-matched sibling donor

BACKGROUND

Peripheral blood stem cells (PBSC) may be used as an alternative to bone marrow (BM) for allogeneic transplantation. Since peripheral blood stem cell bank from unrelated volunteer donor has been started in Japan, use of PBSC allografts may be increased. Therefore we surveyed the outcomes of Japanese leukemia children after PBSC and BM transplantation.

PROCEDURE

This retrospective study compared the outcomes of 661 children (0-18 years) with acute lymphoblastic leukaemia (ALL) or acute myeloid leukaemia (AML) who received their first allogeneic peripheral blood stem cell transplantation (PBSCT; n = 90) or bone marrow transplantation (BMT; n = 571) from HLA-matched siblings between January 1996 and December 2007.

RESULT

Neutrophil recovery was faster after PBSCT than after BMT (ALL: P < 0.0001; AML: P = 0.0002), as was platelet recovery (ALL: P = 0.0008; AML: P = 0.0848). However, the cumulative incidence of chronic graft-versus-host disease (GvHD) was higher after PBSCT than after BMT (ALL: 26.0% vs. 9.9%, P = 0.0066; AML: 41.6% vs. 11.1%, P < 0.0001). The 5-year disease-free survival (DFS) was lower after PBSCT than after BMT for ALL (40.6% vs. 57.1%, P = 0.0257). The 5-year overall survival (OS) was lower after PBSCT than after BMT for ALL (42.4% vs. 63.7%, P = 0.0032) and AML (49.8% vs. 71.8%, P = 0.0163). Multivariate analysis revealed the use of PBSC was a significant risk factor for DFS and OS. PBSCT and BMT did not differ in relapse rate, acute GvHD for ALL and AML, or in DFS for AML.

CONCLUSION

PBSC allografts in Japanese children engraft faster but are associated with poorer survival and increased chronic GvHD.

Bone marrow or peripheral blood stem cell transplantation from unrelated donors in adult patients with acute myeloid leukaemia, an Acute Leukaemia Working Party analysis in 2262 patients

BACKGROUND

No survival benefit of using blood stem cells instead of bone marrow (BM) has been shown in matched unrelated donor (MUD) transplantation.

DESIGN AND METHODS

In a retrospective registry analysis, we compared the use of blood stem cells (n = 1502) and BM (n = 760) from unrelated donors in patients aged 18-60 years with acute myeloid leukaemia (AML) undergoing myeloablative conditioning between 1997 and 2008. The blood stem cell recipients were older (P < 0.01), had more advanced disease (P < 0.0001) and received less total body irradiation (P < 0.0001) and more antithymocyte globulin (P = 0.01).

RESULTS

Recovery of neutrophils and platelets was faster with blood stem cells (P < 0.0001). The incidence of acute graft-versus-host disease (GVHD) was similar, but there was more chronic GVHD in the blood stem cell group [hazard ratio (HR) = 1.29, P = 0.02]. There were no significant differences in nonrelapse mortality (NRM), relapse incidence and leukaemia-free survival (LFS) between the two groups amongst patients with AML in remission. In patients with advanced leukaemia, NRM was lower (HR = 0.61, P = 0.02) and LFS was prolonged (HR = 0.67, P = 0.002) when blood stem cells were used. At 3 years, LFS for all patients, regardless of remission status, was 41% for both treatment groups. The outcome was not affected after multivariable analysis adjusted for confounders.

CONCLUSION

Blood stem cells compared with BM in MUD transplantation for patients with AML in remission resulted in the same rates of LFS. In patients with advanced leukaemia, the blood stem cell group had reduced NRM and improved LFS.

Risk stratification–directed donor lymphocyte infusion could reduce relapse of standard-risk acute leukemia patients after allogeneic hematopoietic stem cell transplantation

We studied the impact of risk stratification–directed interventions for minimal residual disease (MRD) on relapse and disease-free survival (DFS) prospectively in 814 subjects with standard-risk acute leukemia receiving allotransplantation in first or second complete remission. A total of 709 subjects were MRD− after transplantation (Group A); 105 subjects were MRD+, 49 received low-dose IL-2 (Group B), and 56 received modified donor lymphocyte infusion (DLI) with or without low-dose IL-2 (Group C). Posttransplantation immune suppression for GVHD was also modified based on MRD state. The cumulative risk of relapse was significantly less and DFS was significantly better in subjects in Group C than in subjects in Group B (P = .001 and P = .002, respectively), but was not different from subjects in Group A (P = .269 and P = .688, respectively). Multivariate analyses confirmed that MRD state and modified DLI were significantly correlated with relapse (P = .000, odds ratio [OR] = 0.255 and P = .000, OR = 0.269) and DFS (P = .001, OR = 0.511 and P = .006, OR = 0.436, respectively). These data suggest that risk stratification–directed interventions with modified DLI in patients with standard-risk acute leukemia who are MRD+ after transplantation may improve transplantation outcomes.

Unrelated donor peripheral blood stem cell transplants incorporating pre-transplant in-vivo alemtuzumab are not associated with any increased risk of significant acute or chronic graft-versus-host disease

There is little information published comparing peripheral blood stem cells (PBSC) with bone marrow (BM) as the stem cell source in the long-term outcome in recipients of T-cell depleted (TCD) unrelated donor (UD) transplants. We present retrospective outcome data on 306 recipients of myeloablative, human leucocyte antigen-matched UD allografts using pre-transplant in-vivo Alemtuzumab. Transplants were performed between 2000 and 2007 for chronic myeloid leukaemia in first chronic phase and acute leukaemia in first or second complete remission; 184 patients received BM and 122 PBSC. The median age was 28·9 years (<1-58) and the median follow-up was 48 months. Overall survival at 8 years was 53%. The incidence of acute graft-versus-host disease (GvHD) was significantly higher in PBSC (65%) than BM recipients (49%; P=0·012). This represented only grade 1 GvHD with no difference in grade II-IV aGvHD (BM 23% PBSC 24%). The incidence of chronic GvHD, either overall (BM 47%, PBSC 49%) or extensive (BM 15%, PBSC 13%) was not increased with PBSC. The incidence of relapse, non-relapse mortality and survival were not significantly different. Whilst accepting the limitations of retrospective analyses, we suggest the increased risk of GvHD in recipients of PBSC in T-replete transplants is offset by in-vivo Alemtuzumab, and that either stem cell source can be used with good outcomes in this setting.

Allogeneic hematopoietic stem cell transplantation for adult acute lymphocytic leukemia

Allogeneic hematopoietic stem cell transplantation (alloHCT) is the single most potent treatment modality to prevent relapse in adults with acute lymphocytic leukemia, but its optimal use and timing remains a matter of intense debate and research. There is general agreement that patients with clinical features of high risk for relapse should undergo alloHCT in first complete remission. However, newer studies suggest that even patients without these risk factors may benefit. Monitoring of minimal residual disease may improve risk stratification and may complement or replace conventional risk features. Prognosis in relapsed and refractory patients is dismal, and alloHCT should be performed as soon as possible. AlloHCT also offers the only reasonable chance for cure in Philadelphia chromosome-positive acute lymphocytic leukemia; the role of imatinib is not yet clearly defined. Recent developments in unrelated-donor transplantation and reduced-intensity conditioning allow the beneficial effects of alloHCT to reach a considerably wider patient population.

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: report from the Committee on the Epidemiology and Natural History of Relapse following Allogeneic Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is increasingly being used for treatment of hematologic malignancies, and the immunologic graft-versus-tumor effect (GVT) provides its therapeutic effectiveness. Disease relapse remains a cause of treatment failure in a significant proportion of patients undergoing alloHSCT without improvements over the last 2-3 decades. We summarize here current data and outline future research regarding the epidemiology, risk factors, and outcomes of relapse after alloHSCT. Although some factors (eg, disease status at alloHSCT or graft-versus-host disease [GVHD] effects) are common, other disease-specific factors may be unique. The impact of reduced-intensity regimens on relapse and survival still need to be assessed using contemporary supportive care and comparable patient populations. The outcome of patients relapsing after an alloHSCT generally remains poor even though interventions including donor leukocyte infusions can benefit some patients. Trials examining targeted therapies along with improved safety of alloHSCT may result in improved outcomes, yet selection bias necessitates prospective assessment to gauge the real contribution of any new therapies. Ongoing chronic GVHD (cGVHD) or other residual post-alloHSCT morbidities may limit the applicability of new therapies. Developing strategies to promptly identify patients as alloHSCT candidates, while malignancy is in a more treatable stage, could decrease relapses rates after alloHSCT. Better understanding and monitoring of minimal residual disease posttransplant could lead to novel preemptive treatments of relapse. Analyses of larger cohorts through multicenter collaborations or registries remain essential to probe questions not amenable to single center or prospective studies. Studies need to provide data with detail on disease status, prior treatments, biologic markers, and posttransplant events. Stringent statistical methods to study relapse remain an important area of research. The opportunities for improvement in prevention and management of post-alloHSCT relapse are apparent, but clinical discipline in their careful study remains important.

Higher CD34(+) and CD3(+) cell doses in the graft promote long-term survival, and have no impact on the incidence of severe acute or chronic graft-versus-host disease after in vivo T cell-depleted unrelated donor hematopoietic stem cell transplantation in children

The aim of our study was to compare the results of unrelated donor (UD) peripheral blood stem cell transplantation versus UD bone marrow transplantation and to analyze the impact of infused CD34(+) and CD3(+) cell doses on survival and incidence of severe graft-versus-host disease (GVHD) in 187 children who underwent UD hematopoietic cell transplantation with the use of in vivo T cell depletion (antithymocyte globulin or CAMPATH-1H). HLA typing was performed at the "high-resolution" level. Patients receiving > or =10 x 10(6) CD34(+) cells/kg and > or =4 x 10(8) CD3(+) cells/kg had better overall and disease-free survival. Multivariate analysis has shown that both infused CD34(+) cell dose <10 x 10(6)/kg and CD3(+) cell dose <4 x 10(8)/kg were independent risk factors for mortality (relative risk [RR] 1.8 and 1.71, P = .009 and .016, respectively). Regarding disease-free survival, multivariate analysis has revealed another independent risk factor for poor outcome apart from the 2 earlier-mentioned cell doses, which was the use of donors mismatched at 2 HLA antigens or 3 HLA allele/antigens (RR 2.5, P = .004). In age groups 0-10 years and 10-20 years, CD34(+) cell doses higher than the age-adjusted median dose clearly favored survival. Higher infused doses of CD34(+) and CD3(+) cells did not result in an increased rate of severe GVHD. The use of mismatched donors was the only independent risk factor for the incidence of severe acute GVHD (RR 2.2, P = .046). The report demonstrates for the first time in a pediatric cohort, that higher doses of transplanted CD34(+) and CD3(+) cells lead to an improved survival without an increased risk of severe GVHD. The study findings may be limited to the population of patients receiving in vivo T cell depletion, which is now broadly used in unrelated donor setting in Europe.

Unrelated transplantation for poor-prognosis adult acute lymphoblastic leukemia: long-term outcome analysis and study of the impact of hematopoietic graft source

Adults with high-risk acute lymphoblastic leukemia (HR-ALL) have a poor outcome with standard chemotherapy and usually undergo unrelated stem cell transplantation (SCT) if a matched sibling donor is not available. We analyzed the outcome of adult patients with unrelated SCT for HR-ALL and studied the possible effect of the hematopoietic stem cell source of the transplant. A total of 149 adult patients (median age, 29 years, range, 15-59 years) with HR-ALL underwent unrelated SCT in 13 Spanish institutions between 2000 and 2007. Patients in first complete remission (CR1) at transplantation had at least one adverse prognostic factor (advanced age, adverse cytogenetics, hyperleukocytosis, or slow response to induction therapy). ALL was in CR1 in 81 patients (54%), in second CR (CR2) in 37 patients (25%), in third CR (CR3) in 11 patients (7%), and with overt disease in 20 patients (13%). The hematopoietic source was unrelated cord blood (UCB) in 62 patients and an unrelated donor (UD) in 87 patients. The patients undergoing UCB-SCT and UD-SCT were comparable in terms of the main clinical and biological features of ALL, except for a higher frequency of patients with more overt disease in the UCB-SCT group. There was no statistically significant difference in overall survival (OS) or disease-free survival (DFS) at 5 years between the 2 groups. Treatment-related mortality (TRM) was significantly lower in the UCB-SCT group (P = .021). The probability of relapse at 1 year was 17% (95% confidence interval [CI], 7%-27%) for the UD-SCT group and 27% (95% CI, 14%-40%) for the UCB-SCT group (P = .088), respectively. Only disease status at transplantation (CR1, 41% [95% CI, 18%-64%] vs CR2, 51% [95% CI, 17%-85%] vs advanced disease, 66% [95% CI, 46%-86%]; P = .001) and the absence of chronic graft-versus-host disease (74% [95% CI, 46%-100%] vs 33% [95% CI, 17%-49%]; P = .034) were significant factors for relapse. All unrelated transplantation modalities were associated with high treatment-related mortality for adult HR-ALL patients without a sibling donor. UCB-SCT and UD-SCT were found to be equivalent options. Disease status at transplantation and chronic GVHD were the main factors influencing relapse in both transplantation modalities.

Stem cell source and outcome after hematopoietic stem cell transplantation (HSCT) in children and adolescents with acute leukemia

Allogeneic hematopoietic stem cell transplantation from siblings, unrelated donors or HLA mismatched family members has become an important procedure to offer a chance of cure to children and adolescents with acute leukemia at high risk of relapse and those with certain genetic diseases. Bone marrow (BM) was the only stem cell source for many years. During the past 15 years, peripheral blood stem cells from granulocyte colony-stimulating factor (G-CSF) mobilized healthy donors, or umbilical cord blood from related or unrelated donors, have become available. Each stem cell source has different risks/benefits for patients and donors, the choice depending not only on availability, but also on HLA compatibility and urgency of the HSCT. This review will analyze the advantages and limitations of each of these options, and the main criteria which can be applied when choosing the appropriate stem cell source for pediatric transplant recipients with acute leukemia.

Allo-hematopoietic cell transplantation for Ph chromosome-positive ALL: impact of imatinib on relapse and survival

The utility of imatinib in either the pre- or post-transplant period for Ph chromosome-positive (Ph+) ALL is uncertain. In addition, there have been recent concerns regarding imatinib and cardiac toxicity. We investigated the outcome of 32 patients with Ph+ ALL who received an allo-hematopoietic cell transplant (HCT) at the University of Minnesota between 1999 and 2006. The median age at HCT was 21.9 years (range: 2.8-55.2). All patients were conditioned with CY and TBI. GVHD prophylaxis was CsA based. Of the 32 patients, 15 received imatinib therapy pre- or post-HCT (imatinib group) and 17 patients received either no imatinib (n=11) or only after relapse (n=6) (non-imatinib group). Overall survival, relapse-free survival and relapse at 2 years was 61, 67 and 13% for the imatinib group as compared with 41, 35 and 35% for the non-imatinib group (P=0.19, 0.12 and 0.20, respectively). Cardiac toxicity and TRM at 2 years were similar between groups. Thus, patients treated with imatinib in either the pre- or post-transplant setting had trends toward improved outcomes and no increase in cardiac toxicity. We suggest that imatinib be included in the peri-transplant management of all patients with Ph+ ALL.

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

Clinical research examining the role of hematopoietic stem cell transplantation (HSCT) in the therapy of acute myelogenous leukemia (AML) in adults 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 Table 3, entitled Summary of Treatment Recommendations Made by the Expert Panel for Adult Acute Myelogenous Leukemia, and were reached unanimously by a panel of AML experts. The identified priority areas of needed future research in adult AML include: (1) What is the role of HSCT in treating patients with specific molecular markers (eg, FLT3, NPM1, CEBPA, BAALC, MLL, NRAS, etc.) especially in patients with normal cytogenetics? (2) What is the benefit of using HSCT to treat different cytogenetic subgroups? (3) What is the impact on survival outcomes of reduced intensity or nonmyeloablative versus conventional conditioning in older (>60 years) and intermediate (40-60 years) aged adults? (4) What is the impact on survival outcomes of unrelated donor HSCT vesus chemotherapy in younger (<40 years) adults with high risk disease?

Peripheral blood progenitor cell or bone marrow transplantation: controversy remains

PURPOSE OF REVIEW

The paper compares bone marrow and peripheral blood progenitor cell transplantations in the allogeneic setting.

RECENT FINDINGS

Peripheral blood progenitor cell use has emerged as an international standard of care for hematopoietic transplantation. These cells have a different cellular composition including higher numbers of CD34 cells and markedly higher numbers of T lymphocytes. Current data support the general safety of this approach for normal transplant donors. Results consistently indicate more rapid hematopoietic recovery compared with bone marrow transplantation. This may result in improved early survival in adults with high-risk leukemias, but longer follow-up has demonstrated an increased rate of chronic graft-versus-host disease morbidity and mortality which may obviate the long-term benefit.

SUMMARY

It is unclear whether peripheral blood progenitor cell or bone marrow transplantation will produce improved disease-free or overall survival. Additional studies with long-term follow-up are necessary to resolve these controversies.

Peripheral blood grafts from unrelated donors are associated with increased acute and chronic graft-versus-host disease without improved survival

Few studies have tested the benefits of using peripheral blood stem cell (PBSC) grafts versus bone marrow (BM) grafts for unrelated donor transplantation. Yet there has been a substantial change in clinical practice, with increasing numbers of adults receiving unrelated donor PBSC grafts. We compared outcomes after 331 PBSC and 586 BM transplants in adults with leukemia and myelodysplastic syndrome (MDS) who were followed for a median of 3 years after transplantation. PBSC recipients were less likely to have chronic myelogenous leukemia (CML) and more likely to have MDS, to have poor performance scores, and to be transplanted more recently. Outcomes were analyzed using Cox regression models. Rates of grades 2-4 acute graft-versus-host disease (GVHD) (58% versus 45%, P < .001) and chronic GVHD (cGVHD) (56% versus 42%, P < .001) were significantly higher with PBSC than with BM transplants. Rates of grade II-IV aGVHD were similar with PBSC and BM transplants. The 3-year probabilities of treatment-related mortality (TRM), leukemia recurrence, leukemia-free, and overall survival (OS) were similar in the 2 groups with 3-year leukemia-free survival rates of 30% and 32% after transplantation of PBSC and BM, respectively. Unlike results after HLA-matched sibling donor PBSC transplants, we did not identify a survival advantage with PBSC grafts in patients receiving unrelated donor transplants for advanced leukemia. The higher rate of cGVHD after PBSC transplants and, consequently, more frequent late adverse events warrant extended follow up of PBSC recipients.

How I treat acute lymphocytic leukemia in adults

The treatment of newly diagnosed acute lymphocytic leukemia (ALL) in adults remains unsatisfactory. Not withstanding the outstanding progress in curing childhood ALL, only approximately one third of adults younger than 60 years can be cured, and the overall published survival curves have not changed significantly during the past 15 years. Recent therapeutic advances in allogeneic transplantation through the conduct of large collaborative studies, better understanding of the relevance of cytogenetics, improved molecular techniques for the detection of minimal residual disease, and clinical research into novel biologic and targeted therapies have all combined to offer potentially a better hope for an improved outcome in this disease. The current approach in 2007 to the management of this disease is presented by way of a discussion of illustrative cases. In this uncommon and difficult disease, well-structured intergroup studies will remain vital for future progress.

Which Patients with Adult Acute Lymphoblastic Leukemia Should Undergo a Hematopoietic Stem Cell Transplantation? Case-Based Discussion

The decision to proceed to transplant for adult patients with acute lymphoblastic leukemia (ALL) is not clear-cut. Relapse and nonrelapse mortality continue to plague the outcome of hematopoietic stem cell transplantation (HSCT) even when undertaken in complete remission (CR). Those considered to be at high risk for relapse often are considered for HSCT in first complete remission (CR1) while those at lower risk may not be referred until they have relapsed, when their chances for cure are very poor. In some patients who have a suitable histocompatible sibling, disease- or patient-related factors may override the potential benefit of allogeneic HSCT. Because many patients do not have a suitable histocompatible sibling, one has to consider the relative merits of autologous transplantation versus use of an alternative allogeneic stem cell source, such as a matched-unrelated donor (MUD), umbilical cord blood (UCB) donor, or haploidentical donor. Deciding among these options in comparison to chemotherapy even in high-risk patients is difficult. In the review, the risks and benefits of these choices are discussed to determine whether and by what means to proceed to HSCT in adult patients with ALL who are in CR1. Presented are two patients with ALL and a discussion of how the data we provide would lead to a decision about the selection of therapy.

Quantitative analysis of chimerism after allogeneic stem cell transplantation by real-time polymerase chain reaction with single nucleotide polymorphisms, standard tandem repeats, and Y-chromosome-specific sequences

We compared the results of chimerism analyses with real-time SNP-PCR to those obtained by the classical STR-PCR method in 135 hematopoietic stem cell transplantation recipients. Using 10 different SNP gene loci, the SNP-PCR method was able to discriminate patient from donor cells in 125 of 135 cases (93%), whereas the use of 11 different STR gene loci with the STR-PCR analysis using agarose or polyacrylamide gel resolution resulted in accurate donor-host discrimination in all patients. Of the 470 analyzed samples we found in 74% concordant results for both chimerism methods. In all 26% discordant cases the SNP-chimerism method showed mixed chimerism (MC), whereas the STR-method found complete chimerism (CC). As a consequence, the SNP-PCR chimerism analysis method detected a MC prior to the occurrence of relapse significantly earlier than the STR-PCR chimerism method (120 vs. 30 days, P < 0.007). The probability of relapses was significantly higher in patients with increasing MC (70%) compared to 30% in patients with CC (P < 0.00001) associated with a significantly shorter overall survival in patients with increasing MC. The multivariate Cox model showed that chimerism analsis with SNP-PCR was the only significant risk factor predicting relapse (RR 6.08, P < 0.0001).Furthermore, we analyzed the chimerism status in male recipients with a female donor in 580 samples of 134 patients using quantitative real-time PCR of Y-chromosome-specific sequences and compared the results with interphase XY-fluorescent in situ hybridization (FISH). MC without signs of relapse was detected in 35% of samples using quantitative real-time PCR of Y-chromosome-specific sequences. The detected Y-DNA amounts were low compared to the amounts detected in 104 samples of 42 patients with leukemic relapse at the time of analysis (P < 0.0001). Quantitative real-time PCR of Y-chromosome-specific sequences detected therefore an increasing MC with high residual host DNA amounts approximately 143 days (mean) prior to the occurrence of relapse. By comparing the results of Y-chromosome PCR with the XY-FISH analysis we found concordant results in 73% in patients with myeloablative regimens. The XY-FISH could detect 12 relapses, whereas the Y-chromosome PCR detect 36 relapses by MC (P < 0.005). Residual host cells gradually decreased during the posttransplant period from a mean of 5.4 ng (first months) to 0.5 ng (above 5 years) without evidence of relapses. The probability of relapses was significantly higher in patients with increasing MC (100%) compared to 8% in patients with CC (P < 0.00001) associated with a significantly shorter overall survival in patients with increasing MC. The multivariate Cox model showed that chimerism analysis of Y-chromosome-specific sequences is an important risk factor for relapse (RR 17.0, P < 0.0001). We conclude that the use of real-time SNP or Y-PCR may be superior to the STR-PCR or interphase XY-FISH methods in detecting patients who are at high risk for relapse after transplant.

The Role of Cytotoxic Therapy with Hematopoietic Stem Cell Transplantation in the Therapy of Acute Lymphoblastic Leukemia in Adults: An Evidence-based Review

Evidence supporting the role of hematopoietic stem cell transplantation (SCT) in the therapy of acute lymphoblastic leukemia in adults (> or =15 years) is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published medical 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 and were reached unanimously by a panel of acute lymphoblastic leukemia experts. The priority areas of needed future research for adult acute lymphoblastic leukemia are: definition of patients at high risk in first complete remission, beyond Philadelphia chromosome positive; outcomes of SCT in older (>50 years) adults; determination if reduced intensity versus myeloablative conditioning regimens yield an equivalent graft-versus-leukemia effect with reduced toxicity; monitoring of minimal residual disease to achieve disease control before SCT; and the use of cord blood and other alternative sources of stem cells for use in adult SCT recipients.

Unrelated donor or partially matched related donor peripheral stem cell transplant with CD34+ selection and CD3+ addback for pediatric patients with leukemias

Unmodified peripheral stem cell transplants are associated with an increased risk of extensive chronic GVHD. T depletion may reduce this risk, but the risk of graft failure or relapse may increase. To decrease the risks of both extensive chronic GVHD and graft failure, we added back a defined dose of CD3+ cells to CD34+ selected PSCs. Twenty-four patients were evaluable for outcome analysis. Donors were unrelated (23) or related (1). Conditioning was thiotepa, cyclophosphamide, and total body irradiation. Cyclosporine was used post transplant. Following CD34+ selection, a total of 5 x 10(5)/kg CD3+ cells were infused. Donors were matched for 12 patients. The median CD34+ dose infused was 7.1 x 10(6)/kg. Engraftment occurred in all patients at a median of 14 days (10-19). Twelve patients are alive in remission 15-34 months (median, 25) post PSCT. GVHD occurred in 17 patients, but was >grade II in only 2. Chronic GVHD occurred in 61.5% of evaluable patients, but was limited to skin and perioral cavity. Two patients relapsed, and 10 patients died of non-relapse causes. This study demonstrates that PSCT with CD34+ selection and a defined dose of CD3+ results in prompt engraftment and may limit development of extensive chronic GVHD.

How and when should we monitor chimerism after allogeneic stem cell transplantation?

SUMMARY

Chimerism analysis has become an important tool for the peri-transplant surveillance of engraftment. It offers the possibility to realize impending graft rejection and can serve as an indicator for the recurrence of the underlying malignant or nonmalignant disease. Most recently, these investigations have become the basis for treatment intervention, for example, to avoid graft rejection, to maintain engraftment and to treat imminent relapse by pre-emptive immunotherapy. This invited review focuses on the clinical implications of characterization of hematopoietic chimerism in stem cell transplantation.

Increased risk of extensive chronic graft-versus-host disease after allogeneic peripheral blood stem cell transplantation using unrelated donors

The long-term follow-up of a study including 214 patients receiving either peripheral blood stem cells (PBSCs) or bone marrow (BM) from an HLA-A, -B, and -DR-compatible unrelated donor is presented. Median follow-up was 4.4 (2.3-7.3) and 5.0 (0.7-8.4) years in the 2 groups, respectively. Cumulative incidence of overall chronic graft-versus-host disease (GVHD) was similar in the 2 groups (78% vs 71%), while extensive chronic GVHD was significantly more common in the PBSC group compared with the BM group (39% vs 24%, P = .03). The 5-year transplant-related mortality (TRM) was 37% in the PBSC group and 35% in the BM controls (P = .7), and overall survival was 42% in both groups. The relapse incidences were 26% and 27% in the 2 groups, respectively, resulting in a disease-free survival of 41% in both groups. In conclusion, PBSCs from HLA-compatible unrelated donors results in similar outcome compared to BM but implies an increased risk for extensive chronic GVHD.

Strategies and clinical implications of chimerism diagnostics after allogeneic hematopoietic stem cell transplantation

Analysis of donor chimerism has become a routine method for the documentation of engraftment after allogeneic hematopoietic stem cell transplantation (HSCT). In recent years several groups have also focused on the application of this technique for the detection of relapsing disease after allogeneic HSCT. This review addresses technical issues (sensitivity, specificity) and discusses the advantages and limitations of methods currently used for chimerism analysis and their usefulness for the detection of MRD. In addition, the potential impact of novel procedures, e.g. subset chimerism or real-time PCR-based procedures, is discussed.

Comparing morbidity and mortality of HLA-matched unrelated donor hematopoietic cell transplantation after nonmyeloablative and myeloablative conditioning: influence of pretransplantation comorbidities

We have carried out HLA-matched unrelated donor hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning in patients with hematologic malignancies who were ineligible for conventional transplantations because of age, comorbidities, or both. The nonmyeloablative regimen consisted of 90 mg/m2 fludarabine and 2 Gy total body irradiation given before and mycophenolate mofetil and cyclosporine given after HCT. This report compares, retrospectively, morbidity and mortality among 60 consecutive patients given nonmyeloablative conditioning (nonablative patients) to those among 74 concurrent and consecutive patients given myeloablative conditioning (ablative patients) before unrelated HCT. The Charlson Comorbidity Index was used to assess pretransplantation comorbidities. Even though nonablative patients had significantly higher pretransplantation comorbidity scores, were older, and had more often failed preceding ablative transplantations and cytotoxic therapies, they experienced fewer grades III to IV toxicities than ablative patients. Further, the incidence of grades III to IV acute graft-versus-host disease (GVHD) was significantly lower in nonablative patients. Both patient groups had comparable 1-year probabilities of chronic GVHD. The 1-year nonrelapse mortality rate was 20% in nonablative patients compared to 32% in ablative patients (hazard ratio=1.4). After adjustment for pretransplantation differences between the 2 patient groups, the hazard ratio was 3.0 (P=.04). Multivariate analyses showed higher pretransplantation comorbidity scores to result in increased toxicity and mortality.

Acute lymphocytic leukemia: role of hematopoietic stem cell transplantation in current management

PURPOSE OF REVIEW

It is still unclear what the best postremission therapy is for young adults with acute lymphocytic leukemia (ALL). Encouraging results, supporting the superiority of allogeneic stem cell transplantation in CR1 compared with chemotherapy/ allogeneic stem cell transplantation (ASCT), are coming from the ongoing international prospective MRC UKALL XII /ECOG 2993 study. However, the transplant-related morbidity and mortality remain high.

RECENT FINDINGS

The detection of persistent minimal residual disease (MRD) after induction and consolidation therapy is being increasingly used to identify high-risk patients for whom allogeneic transplant may offer the only curative option.

SUMMARY

The ultimate aim is to determine whether the absence of MRD pretransplant can be used as a surrogate for low-risk adult ALL that can be cured without allogeneic transplantation.