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Peter Dreger,
Andrea Schnaiter,
Thorsten Zenz,
Sebastian Böttcher,
Marianna Rossi,
Peter Paschka,
Andreas Bühler,
Sascha Dietrich,
Raymonde Busch,
Matthias Ritgen, [......],
Matthias Zeis,
Michael Stadler, Lutz Uharek,
Christof Scheid,
Ute Hegenbart,
Michael Hallek,
Michael Kneba,
Norbert Schmitz,
Hartmut Döhner,
Stephan Stilgenbauer
[show abstract]
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ABSTRACT: The purpose of this analysis was to provide six-year follow-up of the GCLLSG CLL3X trial which studied reduced-intensity allogeneic hematopoietic stem cell transplantation (HSCT) in patients with poor-risk chronic lymphocytic leukemia (CLL), and to investigate the impact of TP53, SF3B1, and NOTCH1 mutations on HSCT outcome. Six-year overall survival (OS) and event-free survival (EFS) of 90 allografted patients was 58% and 38%, respectively. TP53, SF3B1, and NOTCH1 mutations were found in 30%, 26%, and 14% of the trial population. By univariate and multivariate analyses, the mutational status of the TP53, SF3B1, and NOTCH1 genes had no significant impact on OS and EFS. Studies of minimal residual disease confirmed durability of CLL eradication in mutated patients. We conclude that HSCT can provide long-term disease control in patients with poor-risk CLL independent of the presence of TP53, SF3B1, and NOTCH1 mutations. The trial has been registered at the US National Cancer Institute (Protocol Identity # EU-20554, NCT00281983).
Blood 02/2013; · 9.90 Impact Factor
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Il-Kang Na,
Friedrich Wittenbecher,
Mikalai Dziubianau,
Anne Herholz,
Angela Mensen,
Desirée Kunkel,
Olga Blau,
Igor Wolfgang Blau,
Eckhard Thiel, Lutz Uharek,
Carmen Scheibenbogen,
Kathrin Rieger,
Andreas Thiel
[show abstract]
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ABSTRACT: Background. Rabbit antithymocyte globulin-GenzymeTM is used to prevent graft- versus-host disease after allogeneic hematopoietic stem cell transplantation. Common disadvantages of treatment are infectious complications. The effect of rabbit antithymocyte globulin-GenzymeTM on thymic function has not been well- studied. Design and Methods. Multicolor flow cytometry was used to analyze the kinetics of conventional and regulatory T cells in rabbit antithymocyte globulin- GenzymeTM treated (n=12) versus non-treated (n=8) adult patients during the first six months after allogeneic hematopoietic stem cell transplantation. Results. Rabbit antithymocyte globulin-GenzymeTM treated patients exhibited almost undetectable levels of recent thymic emigrants (CD45RA+CD31+) of both conventional and regulatory CD4 T cells throughout the six months after allogeneic hematopoietic stem cell transplantation whereas CD4+CD45RA- memory T cells were less affected, but also significantly lower compared to non-rabbit antithymocyte globulin-GenzymeTM treated patients. In vitro, rabbit antithymocyte globulin-GenzymeTM induced apoptosis and cytolysis of human thymocytes, and its cytotoxic effects were higher compared to rabbit antithymocyte globulin-FreseniusTM. Conclusions. Rabbit antithymocyte globulin-GenzymeTM in combination with conditioning regimen heavily impairs thymic recovery of both conventional and regulatory CD4+ T cells. The sustained depletion of conventional and regulatory CD4+ T cells bears a high risk of both infections and graft-versus-host disease. Our data warrant thymus protective therapies for rabbit antithymocyte globulin-GenzymeTM treated patients and comparative trials to other rabbit antithymocyte globulin preparations or lymphocyte depleting compounds.
Haematologica 07/2012; · 6.42 Impact Factor
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Clemens-Martin Wendtner,
Peter Hillmen,
Daruka Mahadevan,
Andreas Bühler, Lutz Uharek,
Steven Coutré,
Olga Frankfurt,
Adrian Bloor,
Francesc Bosch,
Richard R Furman, [......],
David D Hurd,
Mikkael A Sekeres,
Alessandra Ferrajoli,
Sheetal Shah,
Jennie Zhang,
Laure Moutouh-de Parseval,
Michael Hallek,
Nyla A Heerema,
Stephan Stilgenbauer,
Asher A Chanan-Khan
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ABSTRACT: Based on clinical activity in phase 2 studies, lenalidomide was evaluated in a phase 2/3 study in patients with relapsed/refractory chronic lymphocytic leukemia (CLL). Following tumor lysis syndrome (TLS) complications, the protocol was amended to a phase 1 study to identify the maximum tolerated dose-escalation level (MTDEL). Fifty-two heavily pretreated patients, 69% with bulky disease and 48% with high-risk genomic abnormalities, initiated lenalidomide at 2.5 mg/day, with dose escalation until the MTDEL or the maximum assigned dose was attained. Lenalidomide was safely titrated to 20 mg/day; the MTDEL was not reached. Most common grade 3-4 adverse events were neutropenia and thrombocytopenia; TLS was mild and rare. The low starting dose and conservative dose escalation strategy resulted in six partial responders and 30 patients obtaining stable disease. In summary, lenalidomide 2.5 mg/day is a safe starting dose that can be titrated up to 20 mg/day in patients with CLL.
Leukemia & lymphoma 08/2011; 53(3):417-23. · 2.40 Impact Factor
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Tapani Ruutu,
Liisa Volin,
Dietrich W Beelen,
Rudolf Trenschel,
Juergen Finke,
Marc Schnitzler,
Jerzy Holowiecki,
Sebastian Giebel,
Miroslaw Markiewicz, Lutz Uharek, [......],
Axel R Zander,
Martin Gramatzki,
Roland Repp,
Hermann Einsele,
Gernot Stuhler,
Joachim Baumgart,
Heidrun A Mylius,
Uwe Pichlmeier,
Mathias Freund,
Jochen Casper
[show abstract]
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ABSTRACT: An alternative reduced-toxicity conditioning regimen for allogeneic transplantation, based on treosulfan and fludarabine, has recently been identified. The rationale for this study was to investigate the efficacy and safety of this regimen prospectively in patients with a primary myelodysplastic syndrome.
A total of 45 patients with primary myelodysplastic syndromes were conditioned with 3×14 g/m(2) treosulfan and 5×30 mg/m(2) fludarabine followed by allogeneic hematopoietic stem cell transplantation. Subtypes of myelodysplastic syndromes were refractory anemia with excess blasts-2 (44%), refractory cytopenia with multilineage dysplasia (27%), refractory anemia (9%), refractory anemia with ringed sideroblasts (4%), refractory cytopenia with multilineage dysplasia and ringed sideroblasts (4%), refractory anemia with excess blasts-1 (2%), and myelodysplastic syndrome with isolated del (5q) (2%). The myelodysplastic syndrome was unclassified in 7% of the patients. Forty-seven percent of the patients had a favorable karyotype, 29% an unfavorable one, and 18% an intermediate karyotype. Patients were evaluated for engraftment, adverse events, graft-versus-host disease, non-relapse mortality, relapse incidence, overall survival and disease-free survival.
All but one patient showed primary engraftment of neutrophils after a median of 17 days. Non-hematologic adverse events of grade III-IV in severity included mainly infections and gastrointestinal symptoms (80% and 22% of the patients, respectively). Acute graft-versus-host disease grade II-IV developed in 24%, and extensive chronic graft-versus-host disease in 28% of the patients. After a median follow-up of 780 days, the 2-year overall and disease-free survival estimates were 71% and 67%, respectively. The 2-year cumulative incidences of non-relapse mortality and relapse were 17% and 16%, respectively.
Our safety and efficacy data suggest that treosulfan-based conditioning therapy is a promising treatment option for patients with myelodysplastic syndromes. clinicaltrials.gov identifier: NCT01062490.
Haematologica 06/2011; 96(9):1344-50. · 6.42 Impact Factor
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ABSTRACT: Extramedullary relapses after allogeneic stem cell transplantation, especially within the central nervous system (CNS), are not only difficult to treat but also associated with poor outcome. Although the graft-versus-leukemia (GvL) effect is nowadays accepted and well documented, it remains controversial whether one can make use of GvL effects in immunological-restricted areas ("sanctuary sites") like the central nervous system. Here, we present data of three hematological patients suffering from isolated CNS relapse of CML or AML after allogeneic stem cell transplantation. Patients received in addition to chemotherapy intrathecal infusions of donor lymphocytes by CD14 depletion of peripheral blood mononuclear cells from the correspondent allogeneic donor. Referring to an observation period of maximum 17 months no immediate or delayed side effects could be detected.
Annals of Hematology 02/2011; 90(8):911-6. · 2.62 Impact Factor
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Peter Dreger,
Hartmut Döhner,
Matthias Ritgen,
Sebastian Böttcher,
Raymonde Busch,
Sascha Dietrich,
Donald Bunjes,
Sandra Cohen,
Jörg Schubert,
Ute Hegenbart, [......],
Justin Hasenkamp, Lutz Uharek,
Christof Scheid,
Andreas Humpe,
Thorsten Zenz,
Dirk Winkler,
Michael Hallek,
Michael Kneba,
Norbert Schmitz,
Stephan Stilgenbauer
[show abstract]
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ABSTRACT: The purpose of this prospective multicenter phase 2 trial was to investigate the long-term outcome of reduced-intensity conditioning allogeneic stem cell transplantation (alloSCT) in patients with poor-risk chronic lymphocytic leukemia. Conditioning was fludarabine/ cyclophosphamide-based. Longitudinal quantitative monitoring of minimal residual disease (MRD) was performed centrally by MRD-flow or real-time quantitative polymerase chain reaction. One hundred eligible patients were enrolled, and 90 patients proceeded to alloSCT. With a median follow-up of 46 months (7-102 months), 4-year nonrelapse mortality, event-free survival (EFS) and overall survival (OS) were 23%, 42%, and 65%, respectively. Of 52 patients with MRD monitoring available, 27 (52%) were alive and MRD negative at 12 months after transplant. Four-year EFS of this subset was 89% with all event-free patients except for 2 being MRD negative at the most recent assessment. EFS was similar for all genetic subsets, including 17p deletion (17p-). In multivariate analyses, uncontrolled disease at alloSCT and in vivo T-cell depletion with alemtuzumab, but not 17p-, previous purine analogue refractoriness, or donor source (human leukocyte antigen-identical siblings or unrelated donors) had an adverse impact on EFS and OS. In conclusion, alloSCT for poor-risk chronic lymphocytic leukemia can result in long-term MRD-negative survival in up to one-half of the patients independent of the underlying genomic risk profile. This trial is registered at http://clinicaltrials.gov as NCT00281983.
Blood 10/2010; 116(14):2438-47. · 9.90 Impact Factor
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Wolfgang A Bethge,
Thoralf Lange,
Christoph Meisner,
Stephanie von Harsdorf,
Martin Bornhaeuser,
Birgit Federmann,
Michael Stadler, Lutz Uharek,
Matthias Stelljes,
Stefan Knop,
Gerald Wulf,
Rudolf Trenschel,
Vladan Vucinic,
Helmut Dittmann,
Christoph Faul,
Wichard Vogel,
Lothar Kanz,
Donald Bunjes
[show abstract]
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ABSTRACT: Forty patients were enrolled in this phase 2 study combining radioimmunotherapy (RIT) using yttrium-90-ibritumomab-tiuxetan (15 MBq [0.4 mCi]/kg) with reduced-intensity conditioning (RIC) using fludarabine (90 mg/m(2)) and 2 Gy total body irradiation followed by allogeneic hematopoietic cell transplantation (HCT) from related (n = 13) or unrelated (n = 27) donors for the treatment of advanced non-Hodgkin lymphoma. Diagnoses were follicular lymphoma (n = 17), chronic lymphocytic leukemia (n = 13), mantle cell lymphoma (n = 8), marginal zone lymphoma (n = 1), and lymphoplasmacytic lymphoma (n = 1). Median age was 55 years (range, 34-68 years). All patients were high risk with refractory disease or relapse after preceding autologous HCT. No additional toxicities attributable to RIT were observed. Engraftment was rapid and sustained. Incidences of acute graft-versus-host disease 2-4 and chronic graft-versus-host disease were 43% and 53%, respectively. Kaplan-Meier-estimated nonrelapse mortality was 45% at 2 years. Twenty-two of 40 patients (55%) are alive, resulting in a Kaplan-Meier-estimated 2-year survival of 51% for all, 67% for follicular lymphoma, 49% for chronic lymphocytic leukemia, and 37% for mantle cell lymphoma patients. The combined use of RIT with RIC is feasible with acceptable toxicity, even in elderly and heavily pretreated patients. This study is registered at www.clinicaltrials.gov as #NCT00302757.
Blood 09/2010; 116(10):1795-802. · 9.90 Impact Factor
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Markus M Heimesaat,
Axel Nogai,
Stefan Bereswill,
Rita Plickert,
André Fischer,
Christoph Loddenkemper,
Ulrich Steinhoff,
Sandrine Tchaptchet,
Eckhard Thiel,
Marina A Freudenberg,
Ulf B Göbel, Lutz Uharek
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ABSTRACT: The bacterial microflora aggravates graft-versus-host-disease (GvHD) after allogeneic stem cell transplantation, but the underlying mechanisms of manifestations of intestinal GvHD (iGvHD) in the gut remain poorly understood.
To analyse the gut flora composition and the impact of bacterial sensing via Toll-like receptors (TLRs) in iGvHD.
By mimicking clinical low-intensity conditioning regimens used in humans, a novel irradiation independent, treosulfan and cyclophosphamide-based murine allogeneic transplantation model was established. A global survey of the intestinal microflora by cultural and molecular methods was performed, the intestinal immunopathology in TLR-deficient recipient mice with iGvHD investigated and finally, the impact of anti-TLR9 treatment on iGvHD development assessed.
The inflammatory responses in iGvHD were accompanied by gut flora shifts towards enterobacteria, enterococci and Bacteroides/Prevotella spp. Analysis of iGvHD in MyD88(-/-), TRIF(-/-), TLR2/4(-/-), and TLR9(-/-) recipient mice showed that bacterial sensing via TLRs was essential for iGvHD development. Acute iGvHD was characterised by increasing numbers of apoptotic cells, proliferating cells, T cells and neutrophils within the colon. These responses were significantly reduced in MyD88(-/-), TLR2/4(-/-), TRIF(-/-) and TLR9(-/-) mice, as compared with wild-type controls. However, TRIF(-/-) and TLR2/4(-/-) mice were not protected from mortality, whereas TLR9(-/-) mice displayed increased survival rates. The important role of TLR9-mediated immunopathology was independently confirmed by significantly reduced macroscopic disease symptoms and colonic apoptosis as well as by reduced T-cell and neutrophil numbers within the colon after treatment with a synthetic inhibitory oligonucleotide.
These results emphasise the critical role of gut microbiota, innate immunity and TLR9 in iGvHD and highlight anti-TLR9 strategies as novel therapeutic options.
Gut 08/2010; 59(8):1079-87. · 10.11 Impact Factor
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Martin Schmidt-Hieber,
Igor W Blau,
Gregor Richter,
Seval Türkmen,
Christiane Bommer,
Gundula Thiel,
Heidemarie Neitzel,
Andrea Stroux, Lutz Uharek,
Eckhard Thiel,
Olga Blau
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ABSTRACT: We analyzed karyotype stability in 22 patients with acute leukemia at relapse or disease progression after allogeneic stem cell transplantation (allo-SCT). Karyotypes before and at relapse after allo-SCT were different in 15 patients (68%), the most frequent type being clonal evolution either alone or combined with clonal devolution (13 patients). Patients with and without a karyotype change did not differ significantly in overall survival (OS) (median, 399 vs. 452 days; P = 0.889) and survival after relapse (median, 120 vs. 370 days; P = 0.923). However, acquisition of additional structural chromosome 1 abnormalities at relapse after allo-SCT occurred more frequently than expected and was associated with reduced OS (median, 125 vs. 478 days; P = 0.008) and shorter survival after relapse (median, 37 vs. 370 days; P = 0.002). We identified a previously undescribed clonal evolution involving t(15;17) without PML-RARA rearrangement in an AML patient. We conclude that a karyotype change is common at relapse after allo-SCT in acute leukemia patients. Moreover, our data suggest that additional structural chromosome 1 abnormalities are overrepresented at relapse after allo-SCT in these patients and, in contrast to a karyotype change per se, are associated with reduced OS and shorter survival after relapse.
Cancer genetics and cytogenetics 04/2010; 198(2):135-43. · 1.54 Impact Factor
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Nicolaus Kröger,
Ernst Holler,
Guido Kobbe,
Martin Bornhäuser,
Rainer Schwerdtfeger,
Herrad Baurmann,
Arnon Nagler,
Wolfgang Bethge,
Matthias Stelljes, Lutz Uharek, [......],
Peter Dreger,
Gerald G Wulf,
Hermann Einsele,
Tatjana Zabelina,
Hans Michael Kvasnicka,
Jürgen Thiele,
Ronald Brand,
Axel R Zander,
Dietger Niederwieser,
Theo M de Witte
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ABSTRACT: From 2002 to 2007, 103 patients with primary myelofibrosis or postessential thrombocythemia and polycythemia vera myelofibrosis and a median age of 55 years (range, 32-68 years) were included in a prospective multicenter phase 2 trial to determine efficacy of a busulfan (10 mg/kg)/fludarabine (180 mg/m(2))-based reduced-intensity conditioning regimen followed by allogeneic stem cell transplantation from related (n = 33) or unrelated donors (n = 70). All but 2 patients (2%) showed leukocyte and platelet engraftment after a median of 18 and 22 days, respectively. Acute graft-versus-host disease grade 2 to 4 occurred in 27% and chronic graft-versus-host disease in 43% of the patients. Cumulative incidence of nonrelapse mortality at 1 year was 16% (95% confidence interval, 9%-23%) and significantly lower for patients with a completely matched donor (12% vs 38%; P = .003). The cumulative incidence of relapse at 3 years was 22% (95% confidence interval, 13%-31%) and was influenced by Lille risk profile (low, 14%; intermediate, 22%; and high, 34%; P = .02). The estimated 5-year event-free and overall survival was 51% and 67%, respectively. In a multivariate analysis, age older than 55 years (hazard ratio = 2.70; P = .02) and human leukocyte antigen-mismatched donor (hazard ratio = 3.04; P = .006) remained significant factors for survival. The study was registered at www.clinicaltrials.gov as #NCT 00599547.
Blood 10/2009; 114(26):5264-70. · 9.90 Impact Factor
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ABSTRACT: This study investigated the immunogenicity of Wilms tumor gene product 1 (WT1)-peptide vaccination in WT1-expressing acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) patients without curative treatment option. Vaccination consisted of granulocyte-macrophage colony-stimulating factor subcutaneously days 1 to 4, and WT1.126-134 peptide and 1 mg keyhole limpet hemocyanin on day 3. The initial 9 patients received 4 vaccinations biweekly, then monthly, and the subsequent 10 patients received continual biweekly vaccination. Seventeen AML patients and 2 refractory anemia with excess blasts patients received a median of 11 vaccinations. Treatment was well tolerated. Objective responses in AML patients were 10 stable diseases (SDs) including 4 SDs with more than 50% blast reduction and 2 with hematologic improvement. An additional 4 patients had clinical benefit after initial progression, including 1 complete remission and 3 SDs. WT1 mRNA levels decreased at least 3-fold from baseline in 35% of patients. In 8 of 18 patients, WT1-tetramer(+) T cells increased in blood and in 8 of 17 patients in bone marrow, with a median frequency in bone marrow of 0.18% at baseline and 0.41% in week 18. This WT1 vaccination study provides immunologic, molecular, and preliminary evidence of potential clinical efficacy in AML patients, warranting further investigations.
Blood 05/2009; 113(26):6541-8. · 9.90 Impact Factor
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ABSTRACT: Infections of the central nervous system (CNS) are increasingly reported in patients with malignancies. Heavily immunocompromised patients like those after allogeneic stem cell transplantation (SCT) or previous T cell depleting treatment regimens (e.g. with fludarabine or alemtuzumab) are at highest risk for cerebral infections. The spectrum of causative organisms may vary greatly, depending on the underlying malignancy, its treatment and various other factors. Toxoplasma gondii and fungi are the leading causative organisms in patients after allogeneic SCT, but also viruses such as herpes simplex virus or JC virus may be detected in these patients. Definitive diagnosis of cerebral infection still remains a high challenge, although diagnostics have improved by the wide availability of imaging techniques and polymerase chain reaction in recent years. Novel therapeutic options are arising, particularly for fungal CNS infections. Here, we summarise aspects on epidemiology, clinical symptoms and prognosis of CNS infections in patients with malignancies. Additionally, we give an overview on the diagnostics and management of cerebral infections in these patients including evidence evaluation of efficacy of treatment.
Leukemia & lymphoma 12/2008; 50(1):24-36. · 2.40 Impact Factor
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ABSTRACT: Although ATG is frequently used in hematopoietic stem cell transplantation and solid organ transplantation, little is known on its effects on NK cells, which mediate important functions in post-transplantation immunology. We incubated peripheral blood lymphocytes of healthy donors with Thymoglobulin, Lymphoglobulin or ATG-Fresenius. Cell death and apoptosis of NK cells and T cells were determined by flow cytometry using propidium iodide and Annexin V. As expected, there were no significant differences between the different ATGs regarding their T cell toxicity. Surprisingly, we found profound differences between the different ATGs regarding their impact on NK cells: In clinically relevant concentrations Lymphoglobulin had less toxic effects on NK cells as compared to Thymoglobulin or ATG-Fresenius: the median percentages of apoptotic or necrotic NK cells in response to 1 mug/ml Lymphoglobulin, ATG-Fresenius and Thymoglobulin were 2%, 35% and 38%, respectively (p<0.001). This is the first report of differential effects of different ATGs on NK cells. Lymphoglobulin appears to be superior to Thymoglobulin or ATG Fresenius regarding the preservation of NK cell mediated immunity. Randomized trials addressing the impact of different ATGs on lymphocyte subpopulations in the clinical setting are urgently warranted.
Transplant Immunology 11/2007; 18(2):85-7. · 1.46 Impact Factor
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ABSTRACT: Porous ceramics made of alumina and hydroxyapatite were created using a protein foaming method. Porosity and pore size distribution were successfully varied by means of chemical modification of the foaming protein Bovine serum albumin (BSA). The effectiveness of the BSA and of its chemical modifications as well as the influence of the dispersing agent were investigated using synchrotron tomography. Resulting porous ceramic materials were used as three-dimensional substrates for the cultivation of human peripheral stem cells. The cells proliferated and differentiated in culture. Five cell lines consistent with human blood cell lines were observed.
Journal of Materials Science Materials in Medicine 08/2007; 18(7):1333-8. · 2.32 Impact Factor
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Ralf G Meyer,
Cedrik M Britten,
Daniela Wehler,
Klaus Bender,
Georg Hess,
Abdo Konur,
Udo F Hartwig,
Thomas C Wehler,
Andrew J Ullmann,
Chiara Gentilini, Lutz Uharek,
Christoph Huber,
Karin Kolbe,
Wolfgang Herr
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ABSTRACT: Allogeneic hematopoietic stem cell transplantation (SCT) regimens incorporating the lymphocytotoxic CD52 antibody alemtuzumab demonstrate efficient engraftment and reduced graft-versus-host disease (GVHD). However, these protocols substantially impair posttransplantation antiviral and antitumor immunity. To accelerate immune reconstitution after alemtuzumab-based reduced-intensity SCT, we administered prophylactic CD8-depleted donor lymphocyte infusions (DLIs) starting on days 60 and 120 after transplantation. DLIs were processed in an immunomagnetic good manufacturing practice depletion procedure resulting in a 2.5- to 6-log reduction in CD8 T cells. Of 23 high-risk patients with hematologic malignancies, 11 received a total of 21 CD8-depleted DLIs. Five patients developed transient grade I acute GVHD following transfer. Only 2 patients with HLA-C-mismatched donors showed grade II and III acute GVHD and subsequently progressed to limited chronic GVHD. Following DLIs, 4 patients with declining hematopoietic donor chimerism converted to full chimeras. A 2.1-fold median increase of circulating CD4 T cells was observed within 2 weeks after infusion. Non-DLI patients did not show a comparable rise in CD4 counts. Four patients demonstrated enhanced frequencies of cytomegalovirus-specific CD4 and CD8 T cells following transfer. Our results suggest that prophylactic CD8-depleted DLIs accelerate immune reconstitution after lymphodepleted HLA-matched SCT and carry a low risk of inducing severe GVHD.
Blood 02/2007; 109(1):374-82. · 9.90 Impact Factor
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ABSTRACT: In patients treated with rituximab and alemtuzumab for lymphomas or CLL, antibody-dependent cellular cytotoxicity (ADCC) is a major mechanism of action. Therefore, assessment of ADCC is mandatory to understand the complex mechanisms leading to the anti-lymphoma effects of monoclonal antibodies (mAb). Due to methodical difficulties, little is yet known about the relevant cell subpopulations and effector mechanisms leading to tumor lysis in ADCC.
We used a novel flow cytometric assay that detects CD107a as a marker for NK-cell degranulation to characterize and quantify peripheral blood natural killer (NK) cells mediating ADCC in vitro and in vivo.
We observed specific and dose-dependent NK-cell activation after administration of rituximab and alemtuzumab. The number of degranulating NK cells was closely related to the concentration of mAb and the effector:target ratio. We were able to quantify and characterize the peripheral blood NK cells mediating ADCC. The majority of degranulating NK cells had the phenotype: CD56(dim), CD69(+), NKG2D(+), NKp30(-), NKp46(-), and CD94(-). Furthermore, we found that the CD107a assay can also visualize ADCC under clinical conditions as we observed increased numbers of NK cells degranulating in response to CD20(+) lymphoma cell lines in patients with non-Hodgkin's lymphoma treated with rituximab.
We were able to quantify and characterize NK cells mediating ADCC with a new and feasible method. The CD107a assay may be useful for predicting treatment responses of individual patients and may help find the optimal dosage and timing for treatment with mAb.
Experimental Hematology 07/2006; 34(6):753-9. · 2.90 Impact Factor
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ABSTRACT: There is considerable interest in immunotherapeutic approaches for lymphoma. The expression of proteinase inhibitor 9 (PI-9), a molecule that inactivates granzyme B, is considered an immune escape mechanism in lymphoma. Further, lymphomas frequently overexpress the antiapoptotic molecule bcl-2, which is able to inhibit perforin-dependent cytotoxic pathways. In this study, the impact of PI-9 and bcl-2 expression on the sensitivity of lymphomas to T- and natural killer (NK) cell-mediated cytotoxicity was analyzed. We found PI-9 expression in 10 of 18 lymphoma cell lines and in 9 of 14 primary lymphomas. Overexpression of bcl-2 was found in 8 of 18 cell lines and in 12 of 14 primary lymphomas. All lymphoma cells were sensitive to cytolysis by specific T cells and cytokine-activated NK cells, and no difference in sensitivity was observed with respect to PI-9 or bcl-2 expression. Cytolysis was mediated predominantly through perforin-dependent pathways despite expression of PI-9 and bcl-2. Interestingly, the majority of lymphoma cells were resistant to cytolysis by resting allogeneic NK cells. This was due to the failure of lymphomas to induce degranulation of resting NK cells. These results show that resistance to perforin-dependent pathways is not a relevant immune escape mechanism in lymphoma and therefore is unlikely to impair clinical outcome of immunotherapeutic approaches.
Blood 05/2006; 107(8):3205-11. · 9.90 Impact Factor
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Kathrin Rieger,
Christoph Loddenkemper,
Jochem Maul,
Thomas Fietz,
Daniel Wolff,
Harald Terpe,
Beate Steiner,
Erika Berg,
Stephan Miehlke,
Martin Bornhäuser,
Thomas Schneider,
Martin Zeitz,
Harald Stein,
Eckhard Thiel,
Rainer Duchmann, Lutz Uharek
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ABSTRACT: CD4+CD25+ regulatory T cells (Tregs) control immune responses to self- and foreign antigens and play a pivotal role in autoimmune diseases, infectious and noninfectious inflammation, and graft rejection. Since recent experimental studies have indicated that Tregs were able to ameliorate graft-versus-host disease (GvHD), we analyzed the number of infiltrating Tregs in the intestinal mucosa as one site of GvH reactivity using immunoenzymatic labeling to enumerate FOXP3+ T cells in 95 intestinal biopsies from 49 allografted patients in comparison with healthy controls and patients with infectious inflammation. While patients with cytomegalovirus (CMV)-colitis or diverticulitis showed a concomitant increase of CD8+ effectors and Tregs, acute and chronic GvHD were characterized by the complete lack of a counter-regulation indicated by a FOXP3+/CD8+ T-cell ratio identical to healthy controls. In contrast, specimens without histologic signs of GvHD demonstrated increased numbers of FOXP3+ per CD8+ T cells, indicating that the potential for Treg expansion is principally maintained in allografted patients. Our findings provide evidence that GvHD is associated with an insufficient up-regulation of Tregs in intestinal GvHD lesions. The determination of FOXP3+/CD8+ ratio can be a helpful tool to discriminate GvHD from infectious inflammation after allogeneic stem cell transplantation.
Blood 03/2006; 107(4):1717-23. · 9.90 Impact Factor
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British Journal of Haematology 09/2005; 130(4):468. · 4.94 Impact Factor
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ABSTRACT: Acute graft-versus-host disease (aGVHD) occurs in up to 80% of patients who undergo allogeneic stem cell transplantation (SCT) and contributes significantly to transplant-related mortality (TRM). We conducted a prospective phase II trial to assess the efficacy and feasibility of treating steroid-refractory aGVHD with basiliximab, a chimaeric monoclonal antibody directed against the alpha chain of the interleukin-2 (IL-2) receptor. Basiliximab was administered intravenously at a dose of 20 mg on days 1 and 4. Twenty-three patients were enrolled between October 1999 and July 2004. We found a primary overall response rate of 82.5% with four patients (17.5%) showing a complete response and 15 patients (65%) a partial response. Six patients were again treated successfully with an IL-2 receptor antagonist because of recurrence of aGVHD. The rates of infections, chronic GVHD, malignancy recurrence and 1-year TRM following immunosuppression with basiliximab were comparable with those found with other treatment modalities for aGVHD. We conclude that basiliximab is efficient and feasible for steroid-refractory aGVHD and merits further evaluation.
British Journal of Haematology 09/2005; 130(4):568-74. · 4.94 Impact Factor
