Unrelated donor bone marrow transplantation for children with relapsed acute lymphoblastic leukaemia in second complete remission

TBI, etoposide, and cyclophosphamide conditioning for intermediate-risk relapsed childhood acute lymphoblastic leukemia

BACKGROUND

In children with intermediate-risk relapsed acute lymphoblastic leukemia (ALL), allogeneic hematopoietic stem cell transplantation (allo-HSCT) has markedly improved the outcome of patients with an unsatisfactory minimal residual disease (MRD) response. Total body irradiation (TBI), etoposide (ETP), and cyclophosphamide (CY) have been shown to be equivalent to or better than TBI + ETP for conditioning, so we hypothesized that even greater survival could be achieved due to recent advances in HSCT and supportive care.

PROCEDURE

We prospectively analyzed the efficacy and safety of allo-HSCT with a unified conditioning regimen of TBI + ETP + CY in children with intermediate-risk relapsed ALL, based on MRD in the bone marrow after induction, from the Japanese Pediatric Leukemia/Lymphoma Study Group (JPLSG) ALL-R08-II nationwide cohort (UMIN000002025).

RESULTS

Twenty patients with post-induction MRD ≥ 10-3 and two not evaluated for MRD underwent allo-HSCT. Engraftment was confirmed in all patients, and no transplantation-related mortality was observed. The 3-year event-free survival and overall survival rates after transplantation were 86.4% ± 7.3% and 95.5% ± 4.4%, respectively.

CONCLUSION

Allo-HSCT based on post-induction MRD with TBI + ETP + CY conditioning was feasible in Japanese children with intermediate-risk relapsed ALL.

Comparable Outcomes of Matched Sibling Donor and Matched Unrelated Donor Stem Cell Transplantation in Children With Acute Leukemia in Argentina

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is an effective mode of consolidation therapy for children with high-risk acute leukemia. In high-income countries, match sibling donor (MSD) and match unrelated donor (MUD) HSCT have similar outcomes, but data are scarce in upper-middle-income countries. Our objective was to compare MSD and MUD HSCT outcomes for children with acute leukemia in Argentina.

PATIENTS AND METHODS

This was a single-institution retrospective cohort study. We included children with acute leukemia who underwent HSCT with either MSD or MUD between 2014 and 2019.

RESULTS

The study included 45 patients who received MSD (n=27) or MUD (n=18) for acute leukemia. Event-free survival was not significantly different between MSD (62.3±10.7%) versus MUD (54.2±15.0%; P=0.54) at 5 years. Similarly, there was no significant difference in 5-year overall survival between MSD (71.9±9.8%) versus MUD (65.1±13.5%; P=0.38). The cumulative incidence of treatment-related mortality (P=0.31), cumulative incidence of relapse (P=0.99), and proportion with acute-graft-versus-host disease (P=0.76) and chronic-graft-versus-host disease (P=0.68) were also not significantly different.

CONCLUSIONS

In Argentina, we did not show significant differences in outcomes between MSD and MUD HSCT for children with high-risk leukemia. Future work should focus on strategies to reduce the relapse risk in children with high-risk leukemia in upper-middle-income countries.

Genetically enhanced T lymphocytes and the intensive care unit

Chimeric antigen receptor-modified T cells (CAR-T cells) and donor lymphocyte infusion (DLI) are important protocols in lymphocyte engineering. CAR-T cells have emerged as a new modality for cancer immunotherapy due to their potential efficacy against hematological malignancies. These genetically modified receptors contain an antigen-binding moiety, a hinge region, a transmembrane domain, and an intracellular costimulatory domain resulting in lymphocyte T cell activation subsequent to antigen binding. In present-day medicine, four generations of CAR-T cells are described depending on the intracellular signaling domain number of T cell receptors. DLI represents a form of adoptive therapy used after hematopoietic stem cell transplant for its anti-tumor and anti-infectious properties. This article covers the current status of CAR-T cells and DLI research in the intensive care unit (ICU) patient, including the efficacy, toxicity, side effects and treatment.

Intractable and highly active relapsing multiple sclerosis - role of alemtuzumab

Alemtuzumab is a humanized recombinant monoclonal antibody that was recently approved by the US Food and Drug Administration and the European Medicines Agency for the management of relapsing forms of multiple sclerosis (MS). It has been utilized for the management of chronic lymphocytic leukemia, bone marrow and renal transplantation, or graft versus host disease. Because of its immunomodulatory properties, it was brought into clinical development in MS. One Phase II (CAMMS223) and two Phase III clinical trials (CARE-MSI and -II) have evaluated the safety and efficacy of alemtuzumab in patients with relapsing-remitting MS. Even though its efficacy profile and long-lasting effect have attracted much interest among physicians and patients, it has significant potential adverse effects that may limit its use to patients with active disease. Here, we review the history of drug development of alemtuzumab. Furthermore, we outline the postulated mechanisms of action, clinical evidence, and safety of alemtuzumab for its use as a disease-modifying agent in active and highly active MS.

Treatment of relapsed acute lymphoblastic leukemia: approaches used by pediatric oncologists and bone marrow transplant physicians

BACKGROUND

Management of relapsed B-precursor acute lymphoblastic leukemia (ALL) is challenging and varied. We hypothesized that treatment approaches differ between pediatric oncologists and bone marrow transplant (BMT) physicians.

PROCEDURE

A survey addressing management of relapsed ALL was sent to pediatric oncologists (n = 883) and BMT (n = 86) physicians across North America.

RESULTS

A number of similarities in treatment approaches were identified including: choice of chemotherapy for re-induction/consolidation, preference for unrelated donors (URDs) in very early marrow relapse and the choice to not use URD donors in late marrow relapse. However, differences between the two disciplines were noted. For patients who relapsed 18-36 months from diagnosis, the majority of oncologists (53.7%) would retreat with chemotherapy while a majority BMT physicians (70.3%) recommended URD transplant (P < 0.001). Oncologists were also less likely to use minimal residual disease (MRD) in relapse assessment compared to BMT physicians (52% vs. 67.2%; P = 0.028) and more oncologists believed MRD testing was experimental and/or not proven in relapsed ALL (27.1% vs. 12.3%; P = 0.011).

CONCLUSIONS

This study highlights management differences in children with ALL between pediatric oncologists and BMT physicians, identifying opportunities for collaborative clinical trials.

Improved survival in matched unrelated donor transplant for childhood ALL since the introduction of high-resolution matching at HLA class I and II

We present the first detailed study analysing OS in BMT for paediatric ALL following the introduction of high-resolution (HR) HLA matching. A total of 356 consecutive paediatric ALL stem cell transplants performed between 1988 and 2007 were reviewed; 80 of them were performed following the introduction of HR HLA class I and class II matching to the transplant programme in 2002. Comparisons of matched unrelated donor (MUD) transplant outcomes before and after this period were made. Matching at the HR level for HLA-A, -B, -C, -DRB1 and -DQB1 (HR-MUD) correlated with a greater than 25% improvement in 2- and 5-year OS in paediatric ALL patients transplanted with MUDs (P=0.009, P=0.005, respectively). Two-year OS for contemporaneous HLA-matched sibling transplants (80.8%) and HR-MUD transplants (78.8%) was equivalent. At 6%, non-relapse mortality (NRM) in MUD transplants since 2002 was significantly reduced compared with previous epochs. Changes in treatment and epoch-dependent improvements in outcome were reviewed for possible confounders to the influence of HR typing using univariate and multivariate analysis.

Chronic graft-versus-host disease (GVHD) in children

Five-year survival rates for childhood cancer now exceed 80% and with the significant progress made by the transplant community in developing less toxic conditioning regimens and in the treatment of posttransplant complications, allo-hematopoietic stem cell transplantation (HSCT) contributes significantly to that population of long-term survivors. In this context, the acute and long-term toxicities of chronic graft-versus-host disease (cGVHD) have an ever-increasing effect on organ function, quality of life, and survival; patients and families who initially felt great relief to be cured from the primary disease, now face the challenge of a chronic debilitating illness for which preventative and treatment strategies are suboptimal. Hence, the development of novel strategies that reduce and or control cGVHD, preserve graft-versus-tumor effects, facilitate engraftment and immune reconstitution, and enhance survival after allo-HSCT represents one of the most significant challenges facing physician-scientists and patients.

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.

Hematopoietic stem cell transplantation for leukemia

Leukemia represents the most common pediatric malignancy, accounting for approximately 30% of all cancers in children less than 20 years of age. Most children diagnosed with leukemia are cured without hematopoietic stem cell transplantation (HSCT), but for some high-risk subgroups, allogeneic HSCT plays an important role in their therapeutic approach. The characteristics of these high-risk subgroups and the role of HSCT in childhood leukemias are discussed.

Hematopoietic cell transplantation for children with acute lymphoblastic leukemia in second complete remission: similar outcomes in recipients of unrelated marrow and umbilical cord blood versus marrow from HLA matched sibling donors

Transplant decisions for children with acute lymphoblastic leukemia (ALL) in second complete remission (CR2) are often based on the type of available donor. In many cases, allogeneic hematopoietic cell transplantation (HCT) is considered only if a human leukocyte antigen (HLA) matched sibling donor (MSD) is available. The role of unrelated donor (URD) HCT in this patient population is not well established. As advances in supportive care and donor selection have improved, the use of URD HCT in such patients should be reevaluated. We analyzed the outcomes of 87 consecutive children with ALL in CR2 who underwent allogeneic HCT at the University of Minnesota between 1990 and 2007. Donor sources included MSD bone marrow (n = 32), well and partially matched (M, n = 18) and mismatched (MM, n = 16) URD bone marrow and URD umbilical cord blood (UCB, n = 21). Although the incidence of neutrophil recovery was similar in all groups, the overall incidence of grades II-IV acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD) was 37% and 9%, respectively, with a higher incidence of aGVHD in recipients of URD grafts. Leukemia-free survival (LFS) at 5 years was lower in recipients of MM-URD grafts, but was comparable in all other groups. Although relapse at 5 years was highest in recipients of MSD (50%), results were not significantly different compared to recipients of M-URD (17%), MM-URD (6%), and UCB (33%) (P = .17). The development of grades II-IV aGVHD and a first remission >3 years were associated with a lower risk of relapse (relative risk [RR] 0.2, P = .03; RR 0.2. P = .01 respectively). Together, these results support the continued investigation of URD HCT for ALL in CR2, and suggest the timing of HCT in these children should be based primarily on the risk of relapse with conventional chemotherapy and not on the type of donor available.

Outcome of single fraction total body irradiation-conditioned stem cell transplantation in younger children with malignant disease--comparison with a busulphan-cyclophosphamide regimen

The logistic difficulties of using fractionated total body irradiation (TBI) in the youngest children often limit the choice to single fraction TBI (sfTBI) or non-TBI-based regimens. We retrospectively evaluated 44 such children ( < 7 years) conditioned with either sfTBI (n = 26) or busulphan-cyclophosphamide (Bu-Cy) (n = 18), transplanted for hematological malignancies between 1988 and 2001. Both neutrophil and platelet engraftment were faster in the sfTBI group with a similar incidence of graft failure (6.8%). Acute GVHD (graft versus host disease) grade 2-4 occurred in 38.4% and 38.8% and chronic GVHD in 20% and 15.4% of the patients in the sfTBI and Bu-Cy groups, respectively Grade 2-4 GVHD was associated with reduced risk of relapse (p = 0.03). This finding was more pronounced in high-risk patients with 2/10 relapses in patients with GVHD grade 2-4, compared with 13/18 relapses among those with GVHD 0-1 (p = 0.05). The probability of overall survival was 43.3% in the sfTBI group and 33.3% in the Bu-Cy group (p = 0.6). However, the outcomes for high-risk patients and those with acute lymphoblastic leukemia were better in the sfTBI group. While hypothyroidism, growth hormone deficiency, learning problems and cataract formation were observed only in the sfTBI group, early cardiac toxicity, behavioral problems and seizures were more common in the Bu-Cy group. Thus, where fractionated TBI is not feasible, sfTBI offers improved survival in high-risk children with acute lymphoblastic leukemia compared with Bu-Cy, without an unacceptable increase in early or late toxicity.

Cytolytic activity of NK cell clones against acute childhood precursor-B-cell leukaemia is influenced by HLA class I expression on blasts and the differential KIR phenotype of NK clones

Relapse after allo-SCT in patients with acute leukaemia remains a major problem. A beneficial impact of alloreactive natural killer (NK) cells has been reported for myeloid malignancies, but has been questionable for B-lineage ALL. We analysed lysis of primary paediatric precursor-B-ALL blasts by 285 NK cell clones to investigate whether HLA class I expression on the blasts and phenotypic killer cell Ig-like receptor (KIR) expression on NK cells affect the lytic activity against ALL blasts. Precursor-B-ALL blasts with low HLA-I expression were lysed by a majority (79%) of NK cell clones, whereas those with high HLA-I expression showed low susceptibility to NK clones independent of their KIR expression patterns. NK cell activity against susceptible blasts was regulated by differential surface expression of the three major KIRs (CD158a, CD158b, CD158e). NK clones with none of these three KIRs or a single KIR that recognized no ligand, were not inhibited by the targets and exerted higher lysis (P = <0.0005) in comparison to NK clones expressing KIRs with a ligand on the ALL blasts. In conclusion, the quantity of HLA-I expression on precursor-B-ALL blast regulates overall NK cell susceptibility; in case of reduced HLA expression, differential surface expression of KIRs affects NK cell alloreactivity against those blasts.

Allogeneic hematopoietic SCT in children with ALL: current concepts of ongoing prospective SCT trials

The definition of indications for allogeneic SCT in children with high-risk (HR) ALL in the first remission or after the first or subsequent relapse depends on biological features, response to treatment and survival after chemotherapy alone. As the results of frontline and relapse protocols are improving over time, there is a strong need for prospective SCT trials, ensuring a well-standardized procedure regarding all relevant components that are potentially responsible for heterogeneity in post-SCT outcome. Therefore, in 2003, the ALL-BFM and the ALL-REZ BFM Study Group initiated a prospective, international, multicenter trial (ALL-SCT-BFM 2003). This trial will now be extended to a larger consortium, trial ALL-SCT-BFM-international (ALL-SCT-BFMi). Strict rules define HLA-typing, donor selection, conditioning regimen, GvHD prophylaxis and therapy as well as standards of supportive care to reduce treatment-related mortality and establish an early GVL effect. Moreover, comprehensive and closely reviewed documentation and serious adverse event reporting shall ensure high study quality. Case-by-case discussions of any fatal or critical course during annual meetings will improve the culture of failure management and lead to modifications of guidelines of supportive care. Finally, the results of these prospective trials will determine the current potential of the different SCT procedures in HR or relapsed childhood ALL.

Allogeneic hemopoietic stem cell transplantation for childhood acute lymphoblastic leukemia in second complete remission-similar outcomes after matched related and unrelated donor transplant: a study of the Spanish Working Party for Blood and Marrow Transplantation in Children (Getmon)

The authors report the results of 58 children with ALL in 2CR after related (n = 31) or unrelated (n = 27) AHSCT. Characteristics at diagnosis and initial and after relapse antileukemic treatment were similar in the related donor (RD) and the unrelated donor (UD) groups. Conditioning consisted of TBI/CY +/- VP-16 for patients > or = 3 years old (n = 43) and Bu/CY for the rest. Median recipient age was 8 years (range 1-17) in the RD and 9 years (range 3-14) in the UD group. Median follow-up was 54 months (range 24-80) and 52 months (range 22-85) in the RD and the UD groups repectively. The 5-year EFS probability was 43 +/- 9% for the RD group and 36 +/- 9% in the UD group (p = .25). The transplant-related mortality was 16% in the RD and 37% in the UD group (p = .016). In the RD group 36.7% of patients relapsed versus 18.6% in the UD group (p = .05). GvHD associated with organ failure or infection caused most of the transplant-related deaths in both groups. Survivor quality of life for both groups was good (Lansky score < or = 90).

Poor oral nutrition after allogeneic stem cell transplantation correlates significantly with severe graft-versus-host disease

It has previously been shown that enteral nutrition has several advantages compared to parenteral nutrition (PN) in critically ill patients. The nutritional history was studied in 231 patients after allogeneic stem cell transplantation (SCT). Parenteral nutrition was given for a median of 10 (0-74) days. Patients with graft-versus-host disease (GVHD) grades III-IV received more PN (median 20, range 0-67) than patients with GVHD grades 0-II (10, 0-74, P=0.016). Eighty-five (37%) patients were not able to eat anything for a median of 4 days (1-37). We found a correlation between the number of days with no oral intake (before the diagnosis of acute GVHD) and the incidence of acute GVHD grades III-IV. In patients with 1-4 days of no oral intake, the incidence of grades III-IV acute GVHD was 6%, in those with 5-9 days it was 17%, and in those with >9 days it was 38%. On multivariate analysis, we found that more than 9 days with no oral intake was associated with acute GVHD grades III-IV (odds ratio 7.66, confidence interval 1.44-40.7, P=0.016). Poor oral intake early after SCT may be associated with an increased risk of developing severe acute GVHD.

Hematopoietic stem cell transplantation after first marrow relapse of non-T, non-B acute lymphoblastic leukemia: a pediatric oncology group pilot feasibility study

BACKGROUND

Relapsed acute lymphoblastic leukemia (ALL) in children is associated with a poor outcome, especially for those patients whose relapse occurs during the first 36 months after diagnosis. The best therapy for these patients is not known. This study was designed to evaluate the feasibility of enrolling children with recurrent ALL in a standardized treatment protocol that included receipt of a hematopoietic stem cell transplant (HSCT).

PROCEDURE

Eligible patients with a bone marrow relapse of non-T, non-B ALL underwent a common induction and consolidation followed by receipt of either an allogeneic HSCT from a human leukocyte antigen (HLA)-identical sibling or an autologous HSCT purged with B-4 blocked ricin. A common conditioning regimen was used for all patients.

RESULTS

Twenty-eight patients from eight institutions were enrolled. Fourteen patients did not receive a transplant during the study, because of toxicity (4), relapse (1), inadequate purging (1), and parental or physician preference for an alternative donor transplant (8). Six patients received allogeneic HSCTs. Five of them have remained in remission for a median of 78 months. Eight patients received autologous HSCTs purged with B4-blocked ricin. Four have remained in remission for a median of 94 months. Of the nine patients who received alternative donor transplants, only two remain in remission.

CONCLUSION

We conclude that well designed and controlled prospective studies are necessary to define the role of HSCTs in children with recurrent ALL. In order to be successful, such studies must have the full support of participating centers. Autologous HSC transplantation may have a role in the treatment of relapsed ALL, but further studies are needed.

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

Evidence supporting the role of hematopoietic stem cell transplantation (SCT) in the therapy of acute lymphoblastic leukemia (ALL) 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 a table in this review (Summary of Treatment Recommendations Made by the Expert Panel for Pediatric Acute Lymphoblastic Leukemia) and were reached unanimously by a panel of ALL experts. The priority areas of needed future research in pediatric ALL are unrelated marrow or blood donor versus unrelated cord blood donor allogeneic SCT; alternative, nonfamily allogeneic donor versus autologous SCT; better methods for identifying high-relapse-risk patients; assessments of the effect of current chemotherapy regimens on early relapse; and use of pre-SCT detection of minimal residual disease to predict post-SCT outcomes.

Outcome after first relapse in childhood acute lymphoblastic leukaemia - lessons from the United Kingdom R2 trial

A retrospective analysis of children with first relapse of acute lymphoblastic leukaemia (ALL), treated on the UKALL R2 protocol at four different hospitals, between June 1995 and December 2002 was performed. Of the 150 children 139 (93%) achieved a second complete remission. The overall survival (OS) and event-free survival (EFS) for the whole group was 56% and 47% respectively. The duration of first complete remission and immunophenotype, but not sites of relapse, were predictive for survival. Using the Berlin-Frankfürt-Münster risk stratification for relapsed ALL, the OS and EFS for standard, intermediate (IR) and high risk (HR) groups were 92% and 92%, 64% and 51%, and 14% and 15%, respectively; P < 0.0001 for both OS and EFS. In the IR group, those with a very early isolated central nervous system relapse also had a significantly worse outcome (P = 0.0001). Given the poor outcome of a second relapse, clear strategies are required to identify those in the IR group who will most benefit from stem cell transplantation (SCT). A higher proportion (16%) of induction failures in the HR group suggest the need for novel agents during this phase of treatment, but SCT was associated with a lower relapse rate and better outcome than those treated with chemotherapy alone.

Prognostic factors for relapsed childhood acute lymphoblastic leukemia: impact of allogeneic stem cell transplantation--a report from the Kyushu-Yamaguchi Children's Cancer Study Group

BACKGROUND

The treatment results of childhood acute lymphoblastic leukemia (ALL) with a first relapse were retrospectively analyzed to determine prognostic factors. In particular, an attempt was made to clarify whether stem cell transplantation (SCT) had any advantages over chemotherapy.

PROCEDURES

Of the 407 children with ALL diagnosed between 1984 and 1996, 117 suffered from a relapse before December 1999. The patients were treated differently according to the protocols of each institution. The potential prognostic factors examined were: the time of initial diagnosis, gender, immunophenotype of leukemic blasts and the NCI-risk classification at initial diagnosis, the site of relapse, the time of relapse (early: within 18 months after diagnosis, intermediate: other than either early or late relapse, late: later than 6 months after the discontinuation of front-line chemotherapy), and the treatment after relapse (chemotherapy alone and SCT).

RESULTS

A second complete remission (CR2) was achieved in 90 patients (77%) and thirty of them maintained CR2, thus resulting in an event-free survival rate (EFS) of 25.1% and an overall survival rate of 26.1%. The significant prognostic factors identified by a multivariate analysis included the time of relapse (EFS: early 16.2%, intermediate 23.9%, late 35.1%, P = 0.012) and the treatment after relapse (EFS: SCT 30.3%, chemotherapy 22.0%, P = 0.049). When patients with an isolated bone marrow relapse and continuous CR2 for more than 3 months were analyzed, the treatment in CR2 was the only independent prognostic factor (EFS: SCT 60.2%, chemotherapy 25.7%, P = 0.005).

CONCLUSIONS

In children with ALL and a first relapse, the time of relapse and the treatment after relapse were found to be independent prognostic factors. Allogeneic SCT in CR2 showed significantly better results than chemotherapy in patients with an isolated bone marrow relapse.

Early emergence of PNH-like T cells after allogeneic stem cell transplants utilising CAMPATH-1H for T cell depletion

CAMPATH-1H (C-1H) is widely used in vivo and / or in vitro for T cell depletion in hematopoietic SCT. This humanised monoclonal antibody is specific for CD52, a marker coexpressed on the majority of human lymphocytes with CD48 and other glycosylphosphatidyl-inositol (GPI) anchored proteins. We detected CD52 / CD48 dual expression on >99% of CD3(+) lymphocytes from normal individuals and all 15 post-SCT patients whose transplants did not utilise C-1H. By contrast, 23 / 26 patients with transplants involving C-1H (in vivo, in vitro or both) exhibited populations lacking CD52 expression that accounted for 49.7% (4.2-86.2%) of the CD3+ lymphocytes (median and range) in samples evaluated at a median of 2 months post-SCT. Most CD52- cells also lacked CD48 expression. These GPI- T cells were of either donor or mixed donor / recipient origin. They were predominant in the early months after SCT at times of profound lymphopenia and inversely correlated with the recovery of the absolute lymphocyte count (r= - 0.663, P<0.0001). The presence of CD52- cells has been correlated previously with clinical outcome after CAMPATH therapy for both malignant and nonmalignant diseases.

Factors affecting the outcome of stem cell transplantation from unrelated donors for childhood acute lymphoblastic leukemia in third remission

Between July 1990 and March 2002, 35 consecutive children with ALL in third complete remission (CR3) underwent stem cell transplantation (SCT) from unrelated donors (UD). All patients received CAMPATH-1M 5-20 mg daily for 5 days. Grafts were T-cell depleted in 30 patients, 29 by CAMPATH antibodies and one by CD34 selection. Median follow-up was 3.8 years (0.3-9.3). Event-free survival (EFS) at 3 years was 35% (SE 8%); relapse rate and transplant-related mortality (TRM) at 3 years was 42 and 23%. Short first complete remission (CR1) <2.5 years was associated with lower EFS (P=0.001), higher TRM (P=0.019) and higher relapse rate (P=0.023). Short second complete remission (CR2) <2.5 years was associated with lower EFS (P=0.003) and higher TRM (0.009). Higher relapse rate and lower EFS were associated with isolated first extramedullary relapse (P=0.019, 0.012). There was no significant difference in outcome between mismatched unrelated donor stem cell transplantation (MMUD-SCT) and matched unrelated donor stem cell transplantation (UD-SCT). We conclude that UD-SCT is an effective treatment of ALL in CR3. The outcome remains limited by TRM and a high relapse rate. Short duration of CR1 and of CR2 and extramedullary site at first relapse are particularly adverse. MMUD should also be considered in high-risk patients, since the outcome of MMUD appears similar to MUD.

Risk factors in pediatric stem cell transplantation for leukemia

To investigate which factors impact on survival, relapse, relapse free survival, transplant-related mortality (TRM) and graft-versus-host disease (GVHD) in children who undergo allogeneic stem cell transplantation, we included all 181 children transplanted due to leukemia at our unit. At the end of follow up 54% of the patients were alive, 27% had died due to relapse while 19% had died of other causes. Survival was similar in recipients of related (55%) and unrelated grafts (48%). Risk factors identified in univariate analysis were brought into a multivariable analysis. However, an unrelated donor was not identified as a risk factor for any of the five end-points analysed. A donor positive for three to four herpes viruses increased the risk of acute GVHD, TRM and death. A female to male transplant increased the risk of TRM, particularly if combined with a mismatch. Early stage of disease as well as human leukocyte antigen (HLA)-matching independently predicted survival. The risk of relapse increased after 1992. Chronic GVHD independently decreased the risk of relapse (relative risk RR, 0.39) and death (RR 0.42). We conclude that in children with leukemia other specific donor characteristics such as HLA-matching, gender, parity, and exposure to herpes viruses were more important for outcome than relationship.

Effect of combined T- and B-cell depletion of allogeneic HLA-mismatched bone marrow graft on the magnitude and kinetics of Epstein-Barr virus load in the peripheral blood of bone marrow transplant recipients

Recipients of T-cell-depleted bone marrow (BM) transplants (BMT) frequently develop Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) preceded by a rapid and prominent increase of EBV load in the peripheral blood. The level of this increase positively correlates with the incidence of PTLD. Using a semiquantitative PCR assay we compared the blood levels of EBV-DNA in patients transplanted with either T-cell or T- and B-cell-depleted human leukocyte antigen (HLA)-mismatched BM grafts. Combined T- and B-cell depletion correlated with significantly lower maximal levels of EBV load, which were reached with slower kinetics. These data indicate that B-cell depletion of BM can be used for prophylaxis of PTLD in BM transplant recipients and can affect the long-term balance between EBV and its host.

Factors affecting reconstitution of the T cell compartment in allogeneic haematopoietic cell transplant recipients

The factors affecting T cell reconstitution post haematopoietic cell transplantation (HCT) are not well characterised. We carried out a longitudinal analysis of T cell reconstitution in 32 HCT recipients during the first 12 months post transplant. We analysed reconstitution of naïve, memory and effector T cells, their diversity and monitored thymic output using TCR rearrangement excision circles (TRECs). Thymic-independent pathways were responsible for the rapid reconstitution of memory and effector T cells less than 6 months post HCT. Thymic-dependent pathways were activated between 6 and 12 months in the majority of patients with naïve T cell numbers increasing in parallel with TREC levels. Increasing patient age, chronic GVHD and T cell depletion (with or without pretransplant Campath-1H) predicted low TREC levels and slow naïve T cell recovery. Furthermore, increasing patient age also predicted high memory and effector T cell numbers. The effects of post HCT immunosuppression, total body irradiation, donor leucocyte infusions, T cell dose and post HCT infections on T cell recovery were also analysed. However, no effects of these single variables across a variety of different age, GVHD and T cell depletion groups were apparent. This study suggests that future analysis of the factors affecting T cell reconstitution and studies aimed at reactivating the thymus through therapeutic intervention should be analysed in age-, GVHD- and TCD-matched patient groups.

Clinical and pharmacological risk factors for acute graft-versus-host disease after paediatric bone marrow transplantation from matched-sibling or unrelated donors

The aim of this study was to identify the risk factors for acute graft-versus-host disease (aGVHD) in children transplanted from a matched-sibling donor (MSD) or an unrelated donor (UD). In all, 87 children consecutively underwent allogeneic bone marrow transplantation (BMT) from MSD (n=36), and UD (n=51). GVHD prophylaxis included CsA alone (n=33) or with MTX (n=51). ATG was added in UD-BMT and thalassemic recipients. CsA whole-blood concentrations were measured by EMIT and the dosing regimen was monitored by Bayesian pharmacokinetic modelling. Trough blood concentration (TBC) during the first 2 weeks post transplantation was lower in children who developed grade II-IV aGVHD than those developing no GVHD or only grade I (57+/-9 vs 94+/-8 ng/ml, P=0.007), whereas peak blood concentration and area under concentration curve vs time were similar in both groups. TBC <85 ng/ml and 'use of MTX' were associated with aGVHD in MSD-SCT (P=0.003 and 0.007, respectively) as well as in UD-SCT (P=0.006 and 0.003). Donor age >or=8 years was significant only in MSD-BMT. Our results have shown the significant decisive role of pharmacological factors such as CSA TBC or use of MTX in the occurrence of GVHD in MSD as well as in UD paediatric BMT.

Diagnosis and prognosis of breast and ovarian cancer--a population-based study of 234 women

The diagnosis and prognosis for 135 women with breast cancer and 99 women with ovarian cancer in a well-defined geographical area, and a follow-up of 7-15 years are described, based on patients' records. Diagnosis was initiated in primary care for 53% of women with breast cancer, and for 57% of women with ovarian cancer. Median patient delay was 1 week for breast cancer, and 3.5 weeks for ovarian cancer patients, and median provider delay was 3 weeks for both groups. Crude, relative, and corrected 5-year survival was 73%, 91%, and 82% in breast cancer, and 40%, 49%, and 43% in ovarian cancer. Cox multiple regression analyses showed that stage IIIA and IV, and young age were associated with impaired disease-related survival in breast cancer. In patients with ovarian cancer, stages III and IV at diagnosis, old age, and systemic symptoms dominating at presentation were predictive of reduced disease-related survival while a family history of cancer was predictive of increased survival.

Impact of HLA matching on outcome of hematopoietic stem cell transplantation in children with inherited diseases: a single-center comparative analysis of genoidentical, haploidentical or unrelated donors

SUMMARY

Hematological inherited diseases can be cured by hematopoietic stem cell transplantation (HSCT) from an human leukocyte antigen (HLA)-identical sibling donor (MSD), but the outcome of unrelated donors (URD) or haploidentical donors (HMD) has been a cause of concern. In all, 94 children affected with inherited diseases underwent HSCT at a single center using MSD (group A, n=31), URD (group B, n=23) or HMD (group C, n=40). There was no difference in the rate of engraftment or in the incidence of grades III-IV acute graft-versus-host disease (GVHD) between the groups. Survival rate was 80.6% in group A, 62.5% in group B and 47.5% in group C (P=0.023). In group B, survival rate was 73.7% in the subgroup with zero or one class I mismatch, and 25% in the subgroup with two or more class I mismatches (P=0.04). In group C, survival rate was 83.3% in the 9/10-identical subgroup, 64.3% in the seven or 8/10 subgroup, and 25% in the five or 6/10 subgroup (P=0.0007). Thus, engraftment, incidence of GVHD and survival are similar in recipients of grafts from MSD, URD with 0-1 class I-mismatch, or HMD with at least 7/10 HLA matches. The low success of HSCT using more disparate donors suggests reserving them for patients with very poor prognosis.

The role of haploidentical stem cell transplantation in the management of children with haematological disorders

The broader application of stem cell transplantation (SCT) for paediatric diseases has been limited by a lack of human leucocyte antigen (HLA)-matched donors. Virtually all children, however have at least one haploidentical parent who could serve as a donor. Such a donor is immediately available and the considerable costs of additional HLA typing, registry and banking expenditures that are necessary to procure an unrelated donor, could be reduced. Recent technological advances appear to have overcome the historical problems of graft rejection and severe graft versus host disease in the haploidentical setting, and in the latest studies the overall survival for children undergoing haploidentical SCT for leukaemia is now comparable with that following unrelated donor bone marrow or cord blood transplantation. Post-transplant infectious complications and leukaemia relapse remain the most important barriers yet to overcome, and new directions in the use of adoptive cellular immunity appear to be promising in this respect. Haploidentical SCT is now a viable option for those children who do not have an HLA compatible sibling or fully matched unrelated donor. The relative merits of a haploidentical family donor versus mismatched unrelated bone marrow or cord blood donation needs to be assessed in prospective, randomized clinical trials.

Long-term follow-up of relapsed childhood acute lymphoblastic leukaemia

We have reviewed the outcome after relapse in a cohort of 505 children with acute lymphoblastic leukaemia (ALL) seen at a single institution. The majority of relapses (74%) occurred within 3 years from diagnosis, and most involved the bone marrow alone or with overt extramedullary relapse. Early relapse was more common in children with T-ALL and those with unfavourable cytogenetics. Factors influencing second remission included length of first remission and type of relapse. Children who had not received previous cranial irradiation had a superior survival. The German relapse score involving length of first remission, site of relapse and immunophenotype was highly predictive of outcome: event-free survival with 95% confidence intervals at 6 years for patients who received modern treatment [intensive chemotherapy or bone marrow transplantation (BMT)] was 78% (51-92%) for standard risk, 41% (33-49%) for intermediate risk and 19% (10-31%) for highest risk. Retrospective comparison of BMT with chemotherapy showed no difference in the intermediate-risk group but a possible advantage in the highest risk group. Follow-up of 235 patients who relapsed after chemotherapy and received a third course of treatment showed an extremely high early attrition rate, but a small number of patients survived in third remission. We conclude that new approaches are needed to individualize therapy in intermediate-risk patients and to improve the outcome for those in the highest risk group. Only a small number of children can be treated effectively in third remission.

Stem cell transplantation for chronic myeloid leukemia in children

Hematopoietic stem cell transplantation (SCT) is the only proven cure for chronic myeloid leukemia (CML), a rare disease in childhood. We report outcomes of 314 children with Philadelphia-chromosome-positive (Ph+) CML undergoing SCT from HLA-matched siblings (n = 182) or volunteer-unrelated donors (VUD; n = 132). Three-year overall survival (OS) and leukemia-free survival (LFS) rates were 66% and 55% (n = 314). For 156 children in first chronic phase (CP1) who underwent transplantation from HLA-identical siblings, OS and LFS rates were 75% and 63%. For 97 children who underwent SCT in CP1 from VUD, 3-year OS and LFS rates were 65% and 56%, reflecting higher transplantation-related mortality (TRM) after VUD SCT (35% vs 20%; multivariate hazard ratio [HR], 1.9; 95% confidence interval [CI], 1.0-3.5; P =.05). In a multivariate model for OS and LFS, outcomes were superior in CP1 than in advanced phase (AP/CP1) (OS HR, 2.0; 95% CI, 1.3-3; P =.001; LFS HR, 1.8; 95% CI, 1.2-2.6; P =.003). For relapse, donor source (VUD/sibling) (HR, 0.38; 95% CI, 0.19-0.76; P =.006) and disease stage (AP/CP1) (HR, 2.4; 95% CI, 1.36-4.3; P =.003) were significant. This is the first large series to show that SCT confers long-term LFS in most children with CML and helps assess alternative therapy, including tyrosine kinase inhibitors.

Impact of marrow unrelated donor search duration on outcome of children with acute lymphoblastic leukemia in second remission

We analyzed the outcome of 167 consecutive children with second CR acute lymphoblastic leukemia (ALL), for whom an unrelated donor (UD) search was activated between 1989 and 1998 at a median time of 2 months after relapse. A suitable donor was identified for 70 patients at 1 year and 6.5 months before and after 1995 from search activation, respectively; a further leukemia relapse occurred during the search in 94 children at a median of 4 months after search activation, 36 of whom underwent UD (14) or other types of transplant (22), beyond second CR, while 58 died of progressive disease. Of 73 patients not experiencing a second relapse, 64 underwent UD (46) or other types of transplant (18), while nine proceeded with chemotherapy, and only four of them survived. The 3-year disease-free survival (DFS) from second CR for the 167 patients is 15.1%, whereas 3-year DFS after transplant for the 60 UD and 40 alternative donor transplanted children is 31.6 and 25.4%, respectively. In conclusion, a further relapse is the main factor adversely affecting outcome of children with second CR ALL. Thus, for these patients, the search should be activated early after relapse and either a UD or an alternative transplant should be performed as early as possible.

Low incidence of severe acute graft-versus-host disease in children given haematopoietic stem cell transplantation from unrelated donors prospectively matched for HLA class I and II alleles with high-resolution molecular typing

We evaluated the outcome of 63 children given haematopoietic stem cell transplantation from unrelated donors (URD-HSCT) prospectively selected using DNA high-resolution typing of both HLA class I and class II loci. Thirty patient/donor pairs (48%) were fully matched. Among the others, HSCT was performed in the presence of one (n=22), two (n=9), or three (n=2) HLA disparities. Patients had either malignant (n=46) or non-malignant (n=17) disease. In all cases, graft-versus-host disease (GVHD) prophylaxis consisted of cyclospor-in A, short-term methotrexate and pretransplant anti-thymocyte globulin. The probability of haematopoietic recovery at day 100 was 97%. Two patients experienced primary graft failure. The cumulative probability of grades III-IV acute GVHD and of extensive chronic GVHD equalled 8 and 14%, respectively. A total of 12 patients died of transplant-related complications. The probability of transplant-related mortality (TRM) at 100 and 180 days was 10 and 15%, respectively, whereas the cumulative incidence of TRM was 22%. The probability of GVHD-related mortality equalled 6% at 2.5 years. The overall and disease-free survival rates were 67 and 65%, respectively. URD-HSCT with donor selection based on high-resolution HLA typing is associated with low incidence of both severe acute GVHD and graft failure. The observed outcome is comparable to that of children transplanted from HLA-identical siblings.

Unrelated donor stem cell transplantation compared with chemotherapy for children with acute lymphoblastic leukemia in a second remission: a matched-pair analysis

Allogeneic stem cell transplantation (SCT) is frequently considered as treatment for relapsed childhood acute lymphoblastic leukemia (ALL). For patients without a matched sibling donor, SCT from unrelated donors (UD-SCT) has been increasingly performed during the past years. However, UD-SCT-related mortality and morbidity is still considerable, and the question remains as to which patients are at such high risk of recurrence that UD-SCT is indicated and, conversely, which patients do not require transplantation for long-term disease control. A matched-pair analysis was performed among patients treated according to Acute Lymphoblastic Leukemia Relapse Berlin-Frankfurt-Münster (ALL-REZ BFM) Study Group protocols after first relapse with chemotherapy or UD-SCT. Altogether 81 pairs were identified that could be matched exactly for site of relapse and immunophenotype, and as closely as possible for duration of first remission, age, diagnosis date, and peripheral blast cell count at relapse. No significant difference in the probability of event-free survival (pEFS) between UD-SCT and chemotherapy existed regarding 28 pairs with an intermediate prognosis (0.39 +/- 0.10 vs 0.49 +/- 0.11, P =.105), whereas the pEFS was significantly different in the 53 pairs with a poor prognosis (0.44 +/- 0.07 vs 0.00 +/- 0.00, P <.001). The major reasons of treatment failure among patients who underwent UD-SCT were therapy-related death (TRD; 24/81) and relapses (20/81). In contrast, TRD rarely occurred in patients treated with chemotherapy alone (3/81), but relapse was much more common (62/81). In conclusion, UD-SCT provides better event-free survival for children with high-risk relapsed ALL. However, there is no clear advantage of UD-SCT in patients with intermediate prognosis.

Intestinal graft-versus-host disease: mechanisms and management

Allogeneic haematopoietic stem cell transplantation remains the treatment of choice for a number of malignancies. However, graft-versus-host disease (GVHD) has long been regarded as a serious complication of this procedure. Although GVHD may affect any organ, intestinal GVHD is particularly important because of its frequency, severity and impact on the general condition of the patient. Recent studies have led to progressive elucidation of the mechanism of GVHD. Donor T cells are critical for the induction of GVHD, because depletion of T cells from bone marrow grafts effectively prevents GVHD but also results in an increase of leukaemia relapse. It has been shown that the gastrointestinal tract plays a major role in the amplification of systemic disease because gastrointestinal damage increases the translocation of endotoxins, which promotes further inflammation and additional gastrointestinal damage. Consequently, the management of intestinal GVHD (and the intestine itself) is a subject that should be highlighted. In this article, approaches to the prevention of intestinal GVHD are discussed after being classified into three categories: regimens in common clinical use, regimens under investigation and original regimens used at our hospital. The standard regimen that is used most widely for prevention of GVHD is cyclosporin plus short-term methotrexate. Corticosteroids can be added to this regimen but careful consideration of the adverse effects of these hormones should be considered. Tacrolimus is a newer, more potent alternative to cyclosporin. T-cell depletion (TCD) after transplantation has been shown to prevent acute GVHD, however, the survival benefit of TCD has not been as great as expected. Mycophenolate mofetil can be useful for the treatment of acute GVHD as part of combination therapy. Regimens currently under investigation in animal experiments include suppression of inflammatory cytokines and inhibition of T-cell activation, and, specifically at our institution, hepatocyte growth factor gene therapy. The evidence-based therapy used at our institution includes systemic antibacterial therapy (including eradication of intestinal bacteria) to prevent the intestinal translocation of lipopolysaccharide and avoid the subsequent increase of various inflammatory cytokines. In addition, because of the similarities between intestinal GVHD and ulcerative colitis, sulfasalazine, betamethasone enemas and eicosapentaenoic acid have been used to treat intestinal GVHD in some patients.

Risk factors for moderate-to-severe acute graft-vs.-host disease after allogeneic stem cell transplantation in children

Severe acute graft-vs.-host disease (aGVHD) remains a major cause of transplantation-related mortality. However, because of a graft-vs.-leukaemia effect, a mild (grade I) aGVHD is desirable. As risk factors predisposing for aGVHD are not necessarily the same in children and adults, we have performed a retrospective analysis of risk factors (RFs) for grade II-IV aGVHD in 258 paediatric patients undergoing allogeneic stem cell transplantation at our centre. Thirty-two potential RFs were assessed with univariate analysis in logistic regression. Eleven factors were selected for further evaluation in stepwise elimination multivariate analysis. Three independent RFs were found: (1) donor other than human lekocyte antigen (HLA)-identical sibling [odds ratio (OR) 6.1, p < 0.001); (2) single drug [cyclosporine A (CsA) or methotrexate (Mtx)] graft-vs.-host disease (GVHD) prophylaxis (OR 7.0, p < 0.001); and (3) ABO disparity of any kind (OR 2.4, p = 0.02). The RFs were additive: moderate-to-severe aGVHD was seen in none of the patients without any RFs; in 16% with one RF; in 32% with two RFs and in 67% with all three RFs present. Single drug GVHD prophylaxis (CsA or Mtx), any kind of ABO mismatch, and non-sibling donors are RFs for grade II-IV acute GVHD in paediatric SCT. We encourage the use of combination GVHD prophylaxis in children. ABO mismatch should be considered when choosing between otherwise equally suitable donors.

Transplantation of highly purified CD34+ progenitor cells from unrelated donors in pediatric leukemia

Unrelated donors are commonly used for hematopoietic stem cell transplants, but graft-versus-host disease (GVHD) is a major problem. We investigated whether transplantation of purified mobilized peripheral-blood CD34(+) stem cells from unrelated donors would prevent acute and chronic GVHD in pediatric patients with leukemia and avert the need for pharmacologic immunosuppression. Thirty-one pediatric patients with acute lymphoblastic leukemia (ALL, n = 16), acute myeloid (n = 7), chronic myeloid (n = 6), or juvenile myelomonocytic leukemia (n = 2) underwent transplantation. The median purity of CD34(+) cells after positive magnet-activated cell sorting was 98.5%. Patients received a median of 8.0 x 10(6) CD34(+) cells and 6 x 10(3) CD3(+) T lymphocytes per kilogram, with no posttransplantation pharmacologic immunosuppression. Primary acute GVHD > or = grade II was seen in only 10% of patients (n = 3) and occurred only after human herpesvirus 6 (HHV 6) infection. Two patients had limited chronic GVHD. Engraftment occurred in all patients (primary engraftment, n = 26; engraftment after reconditioning, n = 5). The 2-year survival estimate was 38% for all patients and 63% for patients with ALL in complete remission. Patients with myeloid malignancies had a poor outcome. In comparison to a historical control group who received unmanipulated bone marrow, our patients had a lower incidence of GVHD (P <.001). No difference was observed in the probability of relapse or survival. Study patients with ALL in remission showed a trend toward better survival (P =.07). Transplantation of purified peripheral-blood CD34(+) cells from unrelated donors effectively minimizes GVHD and may be a good therapeutic option for patients with relapsed ALL.

Graft-versus-leukaemia effect in children: chronic GVHD has a significant impact on relapse and survival

To examine whether graft-versus-host-disease (GVHD) is associated with a graft-versus-leukaemia (GVL) effect that also influences the outcome of allogeneic stem cell transplantation (SCT) in childhood acute leukaemia, we evaluated all consecutive (n=169) children who had undergone SCT for ALL and AML at our centre. Median follow-up was 7 years. The 5-year probability of chronic GVHD was 34%. Median time to relapse was 24 months in children with chronic GVHD and 6 months in those without. The corresponding 5-year probabilities of relapse were 30 and 45% (P=0.01). The 5-year probability of survival was 54%. Patients with chronic GVHD had a significantly better survival, 77 vs 51% (P=0.01). In a Cox regression model, chronic GVHD independently decreased the risk of relapse (RR 0.44) and further predicted an increased chance of relapse-free survival (RR 1.7) and survival (RR 2.6). The impact of chronic GVHD on survival was most apparent in late-stage disease and in ALL. Acute GVHD was not an independent predictor for relapse or death in this study. This study is in support of a GVL effect in childhood leukaemia related to chronic GVHD, reducing the risk of relapse and improving survival.

Impact on T-cell depletion and CD34+ cell recovery using humanised CD52 monoclonal antibody (CAMPATH-1H) in BM and PSBC collections; comparison with CAMPATH-1M and CAMPATH-1G

BACKGROUND

Ex vivo T-cell depletion of allogeneic BM (BM) grafts can effectively reduce graft versus host disease (GvHD) and may also apply to transplantation of allogeneic peripheral blood stem cell (PBSC) transplants.

METHODS

Here we have evaluated T-cell depletion and progenitor cell recovery by antibody-mediated cells lysis using three CD52 monoclonal antibodies (MAbs) at different concentrations and cell densities.

RESULTS

CAMPATH-1M was superior to CAMPATH-1H for T-cell depletion of BM samples. Treatment with CAMPATH-1M resulted in up to 2.55 log depletion of CD3+ cells, with recoveries of >or=45% CD34+ cells, >or=67% CFU-GM and >or=65% BFU-E. CAMPATH-1H treatment resulted in up to 1.64 log depletion of CD3+ cells and similar recoveries of CD34+ cells, CFU-GM and BFU-E as seen with CAMPATH-1M. Depletion of CD19+ cells was similar to that observed for CD3+ cells while natural killer (NK) cells were relatively spared compared with the T and B cell populations. Log depletions of T cells from PBSC, as determined by immunofluorescence studies and limiting dilution analyses, were similar using CAMPATH-1M, -1H, and -1G. There were also no differences in the depletion of CD19+ cells or NK cells using the three MAbs. Similar results were obtained for recoveries of CD34+ cells, CFU-GM and BFU-E using all three MAbs, although the recovery of CD34+ cells using the highest concentration of MAbs was significantly greater in CAMPATH-1H treated samples. Increasing the number of PBSC treated with CAMPATH-1H and -1M had no effect on the log depletion of T, B or NK cells and there were no major differences in the log depletions achieved with CAMPATH-1H or -1M. Likewise, the higher PBSC density had no effect on the recoveries of CD34+ cells or committed progenitors and once again CAMPATH-1H gave similar recoveries to those obtained using CAMPATH-1M.

DISCUSSION

Although CAMPATH-1M resulted in greater ex vivo T-cell depletion of BM than CAMPATH-1H, in all other respects, the humanised CAMPATH-1H was just as effective as CAMPATH-1M and -1G.

Improvement over time in outcome for children with acute lymphoblastic leukemia in second remission given hematopoietic stem cell transplantation from unrelated donors

Aims of this study were to verify whether reduction in transplant-related mortality (TRM) of children with acute lymphoblastic leukemia (ALL) in second complete remission (CR) given allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated volunteers has occurred over time and to investigate the role of other variables on the probabilities of relapse, TRM and event-free survival (EFS). We compared results obtained in 26 children given HSCT before January 1998 with those of 37 patients transplanted beyond that date. In all donor-recipient pairs, histocompatibility was determined by serology for HLA-A and -B antigens and by high-resolution DNA typing for DRB1 antigen. High-resolution molecular typing of HLA class I antigens was employed in 20 of the 37 children transplanted more recently. Probability of both acute and chronic GVHD was comparable in the two groups of patients. In multivariate analysis, children transplanted before January 1998, those with T-lineage ALL and those experiencing grade II-IV acute GVHD had a higher relative risk of TRM at 6 months after transplantation. Relapse rate was unfavorably affected by a time interval between diagnosis and relapse <30 months. The 2-year probability of EFS for children transplanted before and after 1 January 1998 was 27% (10-44) and 58% (42-75), respectively (P = 0.02), this difference remaining significant in multivariate analysis. EFS of unrelated donor HSCT in children with ALL in second CR has improved in the last few years, mainly due to a decreased TRM. This information is of value for counseling of patients with relapsed ALL.

A single high dose of idarubicin combined with high-dose ARA-C for treatment of first relapse in childhood 'high-risk' acute lymphoblastic leukaemia: a study of the AIEOP group

The outcome of children with acute lymphoblastic leukaemia (ALL) and early relapse remains unsatisfactory. In January 1995, the AIEOP (Associazione Italiana di Oncologia ed Ematologia Pediatrica) group opened a trial for children with ALL in first isolated or combined bone marrow relapse defined at high risk according to the length of first remission and the immunophenotype. The treatment plan included the combination of a single high-dose idarubicin and high-dose cytarabine as induction therapy followed by an intensive consolidation and stem cell transplant (SCT). In total, 100 children from 16 Italian centres were enrolled; 80 out of the 99 evaluable patients (81%) achieved second complete remission; eight (8%) died during induction and 11 (11%) failed to respond. A total of 42 out of the 80 responders (52.5%) received a SCT: 19 from an identical sibling, 11 from a matched unrelated donor and 12 from umbilical cord blood cells. The estimated 4-year overall survival and event-free survival were 25% and 21% respectively. Disease-free survival at 4 years was 25.8% for the 80 responders. At 4 years, 39 out of 100 children remain alive, with 27 of them free of leukaemia. This induction therapy has shown antileukaemic efficacy with acceptable toxicity; moreover, all responders proved eligible for intensive consolidation.

Unrelated marrow transplantation for children with acute lymphoblastic leukemia in second remission

Allogeneic bone marrow transplantation (BMT) may be curative for more patients than chemotherapy for the child with relapsed acute lymphoblastic leukemia. This study reviewed the outcomes of 363 children with acute lymphoblastic leukemia in second remission who received unrelated donor BMT from 1988 to 2000 in order to define prognostic factors that affect leukemia-free survival (LFS). Median patient age was 9 years (range, 0-19 years), and median follow-up 29 was months (range, 0-125 months). The median duration of first remission was 24 months (range, 0-109 months). Prognostic factors, including age, duration of first remission, HLA matching, and graft-versus-host (GVH) disease, were analyzed using both univariate and multivariate analyses. Overall survival was 38%, and LFS was 36% at 5 years. LFS was significantly worse for patients 15 years or older (log-rank, P =.009). HLA matching was associated with improved LFS. Acute GVH disease developed in 71%, with 29% having grades III-IV. The incidence of chronic GVH disease was 39% for patients who survived more than 80 days and was significantly higher for female patients receiving marrow from female donors (P =.0009). Transplantation-related mortality was 42% and was associated with HLA mismatches, age 15 years and older, and first remission less than 12 months. The 5-year estimate for relapse was 22%, with first remission at least 6 months associated with a lower risk. Results of unrelated donor BMT appear similar to multi-institutional studies of matched related donor BMT, and this approach appears to be curative for many patients. However, innovative approaches are needed for patients with initial remissions of less than 6 months and for older teenagers.