Karl-Walter Sykora

CD56bright cells differ in their KIR repertoire and cytotoxic features from CD56dim NK cells.

In this study we present new differential characteristics of NK cells expressing CD56 surface antigen in low (CD56dim) or high (CD56bright) density. In contrast to CD56bright NK cells CD56dim cells express killer cell immunoglobulin (Ig)‐like receptors (KIR) such as CD158a, CD158b, and NKB1. However, c‐type lectin‐like receptors (KLR) CD94/NKG2 and CD161 are present on both subsets. The ability to form conjugates with susceptible targets is approximately twice as strongly pronounced in CD56dim vs. CD56bright NK cells. Last but not least, granules of CD56dim cells contain about tenfold more perforin and granzyme A enabling potentially more effective cytolysis compared to CD56bright NK cells. On the other hand, CD56bright NK cells are superior in producing the proinflammatory cytokines IFN‐γ (28.5% vs. 20.8%, p<0.05) and TNF‐α (28% vs. 15.8%, p<0.001). The differentNK cell populations retained their specific phenotype in vitro during culture in the presence of IL‐2 contradicting that they simply display different stages of maturity. Taken together our data support the view that CD56bright cells are specialized NK cells that regulate immunological response mechanisms rather by cytokine supply than by their cytotoxic potential. The poor cytolyticcapacity of CD56bright NK cells can be explained by weak ability in forming conjugates with target cells and low contents of perforin and granzyme A in their granules.

Non-Hodgkin's lymphomas of childhood and adolescence: results of a treatment stratified for biologic subtypes and stage--a report of the Berlin-Frankfurt-Münster Group.

PURPOSE To prove the efficacy of a treatment stratified according to histology for children with non-Hodgkins lymphoma (NHL), including acute B-cell leukemia (B-ALL). PATIENTS AND METHODS From October 1986 to March 1990, 302 assessable patients, 0.6 to 17.8 years of age, with newly diagnosed NHL were enrolled onto study ALL/NHL-BFM 86. Fifty percent of patients had Burkitt-type lymphomas, including B-ALL; 24% had lymphoblastic lymphoma; 18% had diffuse large-cell lymphoma; and 8% had an NHL not further classified. Therapy group B included Burkitts-type lymphomas, B-ALL, and most large-cell lymphomas including Ki-1 anaplastic large-cell lymphoma. Patients with stage I and II disease resected received three, while all others received six, 5-day therapy courses (dexamethasone, methotrexate [MTX] 0.5 g/m2 [5 g/m2 for stage IV and B-ALL], and intrathecal [IT] therapy in each course, plus ifosfamide, cytarabine, and etoposide alternating with cyclophosphamide and doxorubicin). Therapy for group non-B patients (lymphoblastic lymphoma and pleomorphic T-cell lymphoma [PTCL]) consisted of a Berlin-Frankfurt-Münster (BFM) acute lymphoblastic leukemia protocol, including cranial irradiation for advanced stage. Local therapy was restricted to patients with incomplete tumor regression. RESULTS The probabilities of event-free survival (pEFS) at 7 years were 80% +/- 2% for the whole group, 81% +/- 3% for group B (n = 225), and 78% +/- 5% for group non-B (n = 77) with a follow-up duration of 3.6 to 7 years (median 5 years). Treatment results were comparable between NHL subtypes, except for PTCL, in which three of four patients suffered from relapse. Local disease manifestations were the most frequent site of failure. CONCLUSION This therapy strategy provided patients of all NHL subtypes with an equally high chance to survive event-free, except patients with PTCL. With reduced systemic failure, local tumor control may become more important.

Prognostic Value of Minimal Residual Disease Quantification Before Allogeneic Stem-Cell Transplantation in Relapsed Childhood Acute Lymphoblastic Leukemia: The ALL-REZ BFM Study Group

PURPOSE Minimal residual disease (MRD) before allogeneic stem-cell transplantation was shown to predict outcome in children with relapsed acute lymphoblastic leukemia (ALL) in retrospective analysis. To verify this, the Acute Lymphoblastic Leukemia Relapse Berlin-Frankfurt-Münster (ALL-REZ BFM) Study Group conducted a prospective trial. PATIENTS AND METHODS Between March 1999 and July 2005, 91 children with relapsed ALL treated according to the ALL-REZ BFM 96 or 2002 protocols and receiving stem-cell transplantation in >or= second remission were enrolled. MRD quantification was performed by real-time polymerase chain reaction using T-cell receptor and immunoglobulin gene rearrangements. RESULTS Probability of event-free survival (pEFS) and cumulative incidence of relapse (CIR) in 45 patients with MRD >or= 10(-4) leukemic cells was 0.27 and 0.57 compared with 0.60 and 0.13 in 46 patients with MRD less than 10(-4) leukemic cells (EFS, P = .004; CIR, P < .001). Intermediate-risk patients (strategic group S1) with MRD >or= 10(-4) leukemic cells (n = 14) had a pEFS of 0.20 and CIR of 0.73, whereas patients with MRD less than 10(-4) leukemic cells (n = 21) had a pEFS of 0.68 and CIR of 0.09 (EFS, P = .020; CIR, P < .001). High-risk patients (S3/4, third complete remission) who received transplantation with an MRD load of less than 10(-4) leukemic cells (n = 25) showed a pEFS and CRI of 0.53 and 0.18, respectively. In contrast, pEFS and CRI were 0.30 and 0.50 in patients who received transplantation with an MRD load of >or= 10(-4) leukemic cells. Multivariate Cox regression analysis revealed MRD as the only independent parameter predictive for EFS (P = .006). CONCLUSION MRD is an important predictor for post-transplantation outcome. As a result, new strategies with modified stem-cell transplantation procedures will be evaluated in ALL-BFM trials.

Increasing Mixed Chimerism Is an Important Prognostic Factor for Unfavorable Outcome in Children With Acute Lymphoblastic Leukemia After Allogeneic Stem-Cell Transplantation: Possible Role For Pre-Emptive Immunotherapy?

PURPOSE We recently reported that children with acute leukemias who show increasing mixed chimerism (MC) after allogeneic stem-cell transplantation have a significantly enhanced risk of relapse. Here we present the results of a prospective multicenter study to investigate (1) whether relapse of acute lymphoblastic leukemia (ALL) can be determined in advance by serial analysis of chimerism, and (2) if outcome can be influenced by withdrawal of immunosuppression and/or by low-dose donor lymphocyte infusion when increasing MC is detected. PATIENTS AND METHODS Serial and quantitative analysis of chimerism was performed using a fluorescent-based short-tandem-repeat-polymerase chain reaction in 163 children with ALL. RESULTS One hundred one patients revealed complete chimerism (CC) or low-level MC (CC/low-level MC); increasing MC was found in 46 patients; and decreasing MC, in 16 patients. Relapse was significantly more frequent in patients with increasing MC (26 of 46) than in patients with CC/low-level MC (eight of 101) or in patients with decreasing MC (0 of 16; P <.0001). The probability of 3-year event-free survival (EFS) was 54% for all patients, 66% for patients with CC/low-level MC (n = 101), 66% for patients with decreasing MC (n = 16), and 23% for patients with increasing MC (n = 46; P <.0001). Of the 46 patients with increasing MC, 31 received immunotherapy. This group had a significantly higher 3-year EFS estimate (37%) than the 15 patients who did not receive immunotherapy (0%; P <.001). CONCLUSION Serial analysis of chimerism reliably identifies patients at highest risk to relapse. The 3-year EFS of patients with increasing MC without immunotherapy was 0%, by which overt relapse could be prevented in a considerable group of patients.

Outcomes of hematopoietic stem cell transplantation for Hurler's syndrome in Europe: a risk factor analysis for graft failure.

Hurlers syndrome (HS), the most severe form of mucopolysaccharidosis type-I, causes progressive deterioration of the central nervous system and death in childhood. Allogeneic stem cell transplantation (SCT) before the age of 2 years halts disease progression. Graft failure limits the success of SCT. We analyzed data on HS patients transplanted in Europe to identify the risk factors for graft failure. We compared outcomes in 146 HS patients transplanted with various conditioning regimens and grafts. Patients were transplanted between 1994 and 2004 and registered to the European Blood and Marrow Transplantation database. Risk factor analysis was performed using logistic regression. ‘Survival’ and ‘alive and engrafted’-rate after first SCT was 85 and 56%, respectively. In multivariable analysis, T-cell depletion (odds ratio (OR) 0.18; 95% confidence interval (CI) 0.04–0.71; P=0.02) and reduced-intensity conditioning (OR 0.08; 95% CI 0.02–0.39; P=0.002) were the risk factors for graft failure. Busulfan targeting protected against graft failure (OR 5.76; 95% CI 1.20–27.54; P=0.028). No difference was noted between cell sources used (bone marrow, peripheral blood stem cells or cord blood (CB)); however, significantly more patients who received CB transplants had full-donor chimerism (OR 9.31; 95% CI 1.06–82.03; P=0.044). These outcomes may impact the safety/efficacy of SCT for ‘inborn-errors of metabolism’ at large. CB increased the likelihood of sustained engraftment associated with normal enzyme levels and could therefore be considered as a preferential cell source in SCT for ‘inborn errors of metabolism’.

Defibrotide in the treatment of children with veno-occlusive disease (VOD): a retrospective multicentre study demonstrates therapeutic efficacy upon early intervention

Summary:Veno-occlusive disease (VOD) of the liver is a complication observed particularly in patients undergoing hematopoietic stem cell transplantation (HSCT). Defibrotide (DF) is a polydeoxyribonucleotide with aptameric activity on endothelium. We evaluated in a retrospective analysis the efficacy of DF in pediatric patients developing hepatic VOD after HSCT.A total of 45 patients between 0.2 and 20 years (median age: 8.2 years) with hepatic VOD were treated with DF: 22 patients (49%) met risk criteria for severe or progressive disease and 23 (51%) for moderately severe and mild disease. The median duration of DF treatment was 17 days. In all, 34 patients (76%) achieved complete response (CR) with a survival rate of 64% at day 100. CR rate in patients with severe disease was 50% with long-term survival of 36%. The average DF dose in the CR group was 45 mg/kg/day and in the no responder (NR) group 27 mg/kg/day. The use of additional drugs besides DF to treat VOD made no difference in the outcome compared to DF alone. The average interval from diagnosis to start of DF was 1 day in the CR and 5.5 days in NR group. In multivariate analysis, early intervention remained the only significant factor for a CR.

Enzyme Replacement Therapy and/or Hematopoietic Stem Cell Transplantation at diagnosis in patients with Mucopolysaccharidosis type I: results of a European consensus procedure

BackgroundMucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder that results in the accumulation of glycosaminoglycans causing progressive multi-organ dysfunction. Its clinical spectrum is very broad and varies from the severe Hurler phenotype (MPS I-H) which is characterized by early and progressive central nervous system (CNS) involvement to the attenuated Scheie phenotype (MPS I-S) with no CNS involvement. Indication, optimal timing, safety and efficacy of the two available treatment options for MPS I, enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation (HSCT), are subject to continuing debate. A European consensus procedure was organized to reach consensus about the use of these two treatment strategies.MethodsA panel of specialists, including 8 specialists for metabolic disorders and 7 bone marrow transplant physicians, all with acknowledged expertise in MPS I, participated in a modified Delphi process to develop consensus-based statements on MPS I treatment. Fifteen MPS I case histories were used to initiate the discussion and to anchor decisions around either treatment mode. Before and at the meeting all experts gave their opinion on the cases (YES/NO transplantation) and reasons for their decisions were collected. A set of draft statements on MPS I treatment options composed by a planning committee were discussed and revised during the meeting until full consensus.ResultsFull consensus was reached on several important issues, including the following: 1) The preferred treatment for patients with MPS I-H diagnosed before age 2.5 yrs is HSCT; 2) In individual patients with an intermediate phenotype HSCT may be considered if there is a suitable donor. However, there are no data on efficacy of HSCT in patients with this phenotype; 3) All MPS I patients including those who have not been transplanted or whose graft has failed may benefit significantly from ERT; 4) ERT should be started at diagnosis and may be of value in patients awaiting HSCT.ConclusionsThis multidisciplinary consensus procedure yielded consensus on the main issues related to therapeutic choices and research for MPS I. This is an important step towards an international, collaborative approach, the only way to obtain useful evidence in rare diseases.

Allogeneic haematopoietic stem cell transplantation in relapsed or refractory anaplastic large cell lymphoma of children and adolescents – a Berlin–Frankfurt–Münster group report

Patients with refractory or early relapsed anaplastic large cell lymphoma (ALCL) have a poor chance of survival. We report 20 children and adolescents with high‐risk relapsed or refractory ALCL who underwent allogeneic haematopoietic stem cell transplantation (HSCT). We retrospectively analysed 20 patients who relapsed between December 1991 and April 2003 during (six patients) or soon after first‐line Berlin–Frankfurt–Münster‐type chemotherapy (14 patients) and underwent allogeneic HSCT. Nine patients received allogeneic HSCT after the first relapse and 11 after multiple relapses. Eight patients received their transplants from matched sibling donors, eight from unrelated donors and four from haploidentical family donors. The conditioning regimen was based on total body irradiation in 15 patients. Two patients relapsed after allogeneic HSCT and died. Three patients died of transplant‐related toxicity. Event‐free survival at 3 years after allogeneic transplant was 75 ± 10%. There was no influence of donor type or conditioning regimen on outcome. Two of six patients with progressive disease during frontline therapy survived compared with 13/14 patients with a first relapse after frontline therapy. Two of three patients who were transplanted with active lymphoma and all five patients who received allogeneic HSCT for relapse following autologous HSCT survived disease‐free. Allogeneic HSCT is effective and has acceptable toxicity as rescue therapy for high‐risk ALCL relapse. It even offers cure for patients refractory to chemotherapy, suggesting a graft‐versus‐ALCL effect.

Monitoring of Adenovirus Infection in Pediatric Transplant Recipients by Quantitative PCR: Report of Six Cases and Review of the Literature

Adenoviral (AdV) infections after transplantation remain a challenge in pediatric patients. Qualitative and quantitative PCR offer new approaches to early diagnosis and monitoring. However, their role in the management of AdV infections in pediatric transplant recipients remains to be determined.

Stem-Cell Transplantation in Children With Acute Lymphoblastic Leukemia: A Prospective International Multicenter Trial Comparing Sibling Donors With Matched Unrelated Donors—The ALL-SCT-BFM-2003 Trial

PURPOSE Although hematopoietic stem-cell transplantation is widely performed in children with high-risk acute lymphoblastic leukemia (ALL), the influence of donor types is poorly understood. Thus, transplantation outcomes were compared in the prospective multinational Berlin-Frankfurt-Muenster (BFM) study group trial: ALL-SCT-BFM 2003 (Allogeneic Stem Cell Transplantation in Children and Adolescents with Acute Lymphoblastic Leukemia). PATIENTS AND METHODS After conditioning with total-body irradiation and etoposide, 411 children with high-risk ALL received highly standardized stem-cell transplantations during the first or later remissions. Depending on donor availability, grafts originated from HLA-genoidentical siblings or from HLA-matched unrelated donors who were identified and matched by high-resolution allelic typing and were compatible in at least 9 of 10 HLA loci. RESULTS Four-year event-free survival (± standard deviation [SD]) did not differ between patients with transplantations from unrelated or sibling donors (0.67 ± 0.03 v 0.71 ± 0.05; P = .405), with cumulative incidences of nonrelapse mortality (± SD) of 0.10 ± 0.02 and 0.03 ± 0.02 (P = .017) and relapse rates (± SD) of 0.22 ± 0.02 and 0.24 ± 0.04 (P = .732), respectively. Among recipients of transplantations from unrelated donors, no significant differences in event-free survival, overall survival, or nonrelapse mortality were observed between 9/10 and 10/10 matched grafts or between peripheral blood stem cells and bone marrow. The absence of chronic graft-versus-host disease had no effect on event-free survival. Engraftment was faster after bone marrow transplantation from siblings and was associated with fewer severe infections and pulmonary complications. CONCLUSION Outcome among high-risk pediatric patients with ALL after hematopoietic stem-cell transplantation was not affected by donor type. Standardized myeloablative conditioning produced a low incidence of treatment-related mortality and effective control of leukemia.