Temporal variation of fungal diversity in a mosaic landscape in Germany.

This study aims at characterizing the diversity and temporal changes of species richness and composition of fungi in an ecotone of a forest border and a meadow in the Taunus mountain range in Germany. All macroscopically visible, epigeous fungi and vascular plants were sampled monthly over three years, together with climatic variables like humidity and temperature that influence fungal diversity and composition as shown by previous studies. In this mosaic landscape, a total of 855 fungal species were collected and identified based on morphological features, the majority of which belonged to Ascomycota (51 %) and Basidiomycota (45 %). Records of fungal species and plant species (218) for this area yielded a fungus to plant species ratio of 4:1, with a plant species accumulation curve that reached saturation. The three years of monitoring, however, were not sufficient to reveal the total fungal species richness and estimation factors showed that a fungus to plant species ratio of 6:1 may be reached by further sampling efforts. The effect of climatic conditions on fungal species richness differed depending on the taxonomic and ecological group, with temporal patterns of occurrence of Basidiomycota and mycorrhizal fungi being strongly associated with temperature and humidity, whereas the other fungal groups were only weakly related to abiotic conditions. In conclusion, long-term, monthly surveys over several years yield a higher diversity of macroscopically visible fungi than standard samplings of fungi in autumn. The association of environmental variables with the occurrence of specific fungal guilds may help to improve estimators of fungal richness in temperate regions.

Sex ratio rather than population size affects genetic diversity in Antennaria dioica.

Habitat fragmentation and small population size can lead to genetic erosion in threatened plant populations. Classical theory implies that dioecy can counteract genetic erosion as it decreases the magnitude of inbreeding and genetic drift due to obligate outcrossing. However, in small populations, sex ratios may be strongly male- or female-biased, leading to substantial reductions in effective population size. This may theoretically result in a unimodal relationship between sex ratios and genetic diversity; yet, empirical studies on this relationship are scarce. Using AFLP markers, we studied genetic diversity, structure and differentiation in 14 highly fragmented Antennaria dioica populations from the Central European lowlands. Our analyses focused on the relationship between sex ratio, population size and genetic diversity. Although most populations were small (mean: 35.5 patches), genetic diversity was moderately high. We found evidence for isolation-by-distance, but overall differentiation of the populations was rather weak. Females dominated 11 populations, which overall resulted in a slightly female-biased sex ratio (61.5%). There was no significant relationship between population size and genetic diversity. The proportion of females was not unimodally but positively linearly related to genetic diversity. The high genetic diversity and low genetic differentiation suggest that A. dioica has been widely distributed in the Central European lowlands in the past, while fragmentation occurred only in the last decades. Sex ratio has more immediate consequences on genetic diversity than population size. An increasing proportion of females can increase genetic diversity in dioecious plants, probably due to a higher amount of sexual reproduction.

A bird pollinator shows positive frequency dependence and constancy of species choice in natural plant communities.

Animal pollinators mediate reproduction of many plant species. Foraging theory suggests that animal pollinators exhibit preferences for common plant species in natural communities (positive frequency-dependent foraging) and temporary single-species specialization (flower constancy) during foraging bouts. Positive frequency dependence may favor common plant species; flower constancy may enhance conspecific pollen transfer particularly in rare plant species. Previous experimental studies suggest that avian pollinators are unlikely to exhibit these behaviors. We studied foraging behavior of Cape Sugarbirds (Promerops cafer), the main avian pollinator of many Protea species, using focal-plant and focal-bird sampling, assisted by high-resolution maps of the spatiotemporal distribution of Protea individuals and their flowering status. We found that Sugarbird's visitation preference increased with species' relative floral abundance, and that individual Sugarbirds tended to visit single species in sequence. Flower constancy during foraging bouts was significantly higher than expected from random plant-animal encounters at the scale of pollinator movements. Positive frequency dependence may favor the reproduction of abundant plant species while flower constancy may be particularly important for rare plant species. This first simultaneous study of both behaviors in a natural plant-pollinator system shows that bird pollinators exhibit both types of behavior and, in this way, possibly influence plant community structure.

Long-term results of adjuvant donor lymphocyte transfusion in AML after allogeneic stem cell transplantation.

Adjuvant transfusion of donor lymphocytes (aDLT) may reduce the risk of relapse after allogeneic stem cell transplantation in high-risk AML. We performed a retrospective analysis on the safety and efficacy of aDLT in a cohort of 46 patients. To be eligible for aDLT, patients had to be in CR for at least 120 days from transplantation, off immunosuppression for ⩾30 days and free of GvHD. Thirty-four patients with similar disease characteristics and fulfilling the same selection criteria served as controls. Median follow-up among aDLT recipients was 7.2 years. Ten patients (22%) relapsed inspite of aDLT, as compared with 53% in the control group. Induction of GvHD was the main complication. However, non-relapse mortality was low with patients dying from infection (n=2), severe chronic GvHD (n=1) and secondary malignancy (n=2). At the time of analysis, 31/46 aDLT recipients were alive in CR at a median of 5.7 years after first aDLT. Overall survival at 7 years after transplant was 67% as compared with 31% in the control group (P<0.001). In conclusion, aDLT is safe, when given in escalating doses to a well predefined group of patients. Long-term survival can be achieved.

Proteomic peptide profiling for preemptive diagnosis of acute graft-versus-host disease after allogeneic stem cell transplantation.

Allogeneic hematopoietic stem cell transplantation is one curative treatment for hematological malignancies, but is compromised by life-threatening complications, such as severe acute graft-versus-host disease (aGvHD). Prediction of severe aGvHD as early as possible is crucial to allow timely initiation of treatment. Here we report on a multicentre validation of an aGvHD-specific urinary proteomic classifier (aGvHD_MS17) in 423 patients. Samples (n=1106) were collected prospectively between day +7 and day +130 and analyzed using capillary electrophoresis coupled on-line to mass spectrometry. Integration of aGvHD_MS17 analysis with demographic and clinical variables using a logistic regression model led to correct classification of patients developing severe aGvHD 14 days before any clinical signs with 82.4% sensitivity and 77.3% specificity. Multivariate regression analysis showed that aGvHD_MS17 positivity was the only strong predictor for aGvHD grade III or IV (P<0.0001). The classifier consists of 17 peptides derived from albumin, ß2-microglobulin, CD99, fibronectin and various collagen α-chains, indicating inflammation, activation of T cells and changes in the extracellular matrix as early signs of GvHD-induced organ damage. This study is currently the largest demonstration of accurate and investigator-independent prediction of patients at risk for severe aGvHD, thus allowing preemptive therapy based on proteomic profiling.

Bioclimatic regions influence genetic structure of four Jordanian Stipa species.

Strong environmental gradients can affect the genetic structure of plant populations, but little is known as to whether closely related species respond similarly or idiosyncratically to ecogeographic variation. We analysed the extent to which gradients in temperature and rainfall shape the genetic structure of four Stipa species in four bioclimatic regions in Jordan. Genetic diversity, differentiation and structure of Stipa species were investigated using amplified fragment length polymorphism (AFLP) molecular markers. For each of the four study species, we sampled 120 individuals from ten populations situated in distinct bioclimatic regions and assessed the degree of genetic diversity and genetic differentiation within and among populations. The widespread ruderals Stipa capensis and S. parviflora had higher genetic diversity than the geographically restricted semi-desert species S. arabica and S. lagascae. In three of the four species, genetic diversity strongly decreased with precipitation, while genetic diversity increased with temperature in S. capensis. Most genetic diversity resided among populations in the semi-desert species (Φ(ST) = 0.572/0.595 in S. arabica/lagascae) but within populations in the ruderal species (Φ(ST) = 0.355/0.387 S. capensis/parviflora). Principal coordinate analysis (PCoA) and STRUCTURE analysis showed that Stipa populations of all species clustered ecogeographically. A genome scan revealed that divergent selection at particular AFLP loci contributed to genetic differentiation. Irrespective of their different life histories, Stipa species responded similarly to the bioclimatic gradient in Jordan. We conclude that, in addition to predominant random processes, steep climatic gradients might shape the genetic structure of plant populations.

Early allo-SCT for AML with a complex aberrant karyotype--results from a prospective pilot study.

In AML, a complex aberrant karyotype is associated with poor response to chemotherapy and dismal prognosis. We prospectively studied the concept of allogeneic haematopoietic SCT (HSCT), performed early and regardless of response to induction treatment in patients with complex karyotype AML (CK-AML). The preparative regimen consisted of fludarabine, Ara-C and amsacrine (FLAMSA) chemotherapy, followed by reduced intensity conditioning (RIC) 3 days later. In vivo T-cell depletion by anti-thymocyte globulin was used to protect from early GvHD, and prophylactic donor lymphocyte transfusion was given from day+120 to augment the GvL effect, once tolerance was established. Eighteen consecutive patients with CK-AML (median age: 53 years) received HSCT from related (n=7) or unrelated (n=11) donors. Before FLAMSA-RIC, nine patients each had received one and two induction courses. Stage at start of FLAMSA-RIC was CR/CRi (n=8) or persistent disease (n=10). Following HSCT, 16 patients achieved CR. After a follow-up of 51 months, 11 patients are alive in CR, whereas seven have died in remission (n=3), or from leukaemia (n=4). Cumulative incidence of relapse, non-relapse mortality, acute GvHD≥II and chronic GvHD were 0.222±0.098, 0.235±0.104, 0.367±0.120 and 0.481±0.123, respectively. Four-year survival from HSCT is 61%. Early HSCT following FLAMSA-RIC may improve the outcome of this unfavourable AML subgroup.

Solid organ transplantation after allogeneic hematopoietic stem cell transplantation: a retrospective, multicenter study of the EBMT.

To analyze the outcome of solid organ transplantation (SOT) in patients who had undergone allogeneic hematopoietic stem cell transplantation (HSCT), a questionnaire survey was carried out within 107 European Group of Blood and Marrow Transplantation centers. This study covered HSCT between 1984 and 2007 in Europe. Forty-five SOT in 40 patients were reported. Fifteen liver, 15 renal, 13 lung, 1 heart and 1 skin transplantations were performed in 28 centers. Overall survival (OS) of patients after SOT was 78% at 5 years (95% confidence interval [CI], 64% to 92%). OS at 5 years was 100% for renal, 71% (95% CI, 46% to 96%) for liver and 63% (95% CI, 23% to 100%) for lung transplant recipients. The 2-year-incidence of SOT failure was 20% (95% CI, 4% to 36%) in patients with graft-versus-host disease (GvHD) and 7% (95% CI, 0% to 21%) in patients without GvHD before SOT. The relapse incidence for underlying malignant diseases was 4% at 5 years (95% CI, 0% to 12%). In summary, this study shows that selected patients receiving SOT after HSCT have a remarkably good overall and organ survival. These data indicate that SOT should be considered in selected patients with single organ failure after HSCT.

Calcineurin inhibitor-free GVHD prophylaxis with sirolimus, mycophenolate mofetil and ATG in Allo-SCT for leukemia patients with high relapse risk: an observational cohort study.

Certain leukemias have a high relapse risk even after allo-SCT, and GVHD prophylaxis with calcineurin inhibitors (CNIs) may interfere with a possible GVL effect. Therefore, we replaced CYA by sirolimus in patients with high relapse risk. In contrast to CNIs, sirolimus promotes the generation of regulatory T-cells and has potent antineoplastic activity. Sirolimus has been used in combination with CNI for GVHD prophylaxis in hematopoietic SCT. However, no CNI-free prophylactic regimen with sirolimus has been evaluated so far. Within the FLAMSA-RIC protocol, 15 patients received GVHD prophylaxis with sirolimus and mycophenolate mofetil (MMF). The underlying diagnoses were relapsed or refractory T-ALL (n=3), AML with FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) or mixed-lineage leukemia-partial tandem duplication (MLL-PTD; n=10; 5 with refractory disease) and CML in refractory myeloid blast crisis (n=2). All evaluable patients (n=14) were engrafted. Grades II-IV acute GVHD occurred in 21% and chronic GVHD in 30% of patients. Non-relapse mortality rate was 14%. No thrombotic microangiopathy or sinusoidal obstruction syndrome was observed. Three patients with FLT3-ITD+ AML relapsed after a median of 112 days. At a median follow-up of 10 months after transplantation, 10 patients are alive and in complete remission. In conclusion, sirolimus-based GVHD prophylactic regimens deserve further investigation.

High antileukemic efficacy of an intermediate intensity conditioning regimen for allogeneic stem cell transplantation in patients with high-risk acute myeloid leukemia in first complete remission.

The goal of this analysis was to define the role of the moderate-intensity fludarabin Ara-C amsacrin (FLAMSA)-reduced intensity conditioning (RIC) regimen for patients with high-risk AML undergoing allogeneic SCT (alloSCT) in first CR1. High-risk was defined by (1) AML secondary to MDS or radio/chemotherapy, (2) unfavorable cytogenetics or (3) delayed response to induction chemotherapy. A total of 23 of 44 AML patients referred to the University of Munich for alloSCT in CR1 between 1999 and 2006 fulfilled these criteria and received FLAMSA chemotherapy, followed by RIC (4 Gy TBI/cyclophosphamide/ATG) for alloSCT. Twenty-two patients engrafted, one died in aplasia. Two-year cumulative incidences for relapse and nonrelapse mortality (NRM) were 4.6 and 22.5%, respectively. Four-year overall and leukemia-free survival was 72.7% (median follow-up among survivors: 35 months). The results of this high-risk cohort were compared to the outcome of 21 consecutive standard-risk patients <55 years, who had received standard, myeloablative sibling SCT in CR1 AML within the same center and time period. Survival and cumulative incidences of relapse and NRM were identical in both groups. In conclusion, the FLAMSA-RIC regimen produces long-term remission in a high proportion of patients with high-risk AML transplanted in CR1. In this cohort, FLAMSA-RIC showed equivalent antileukemic activity as compared to the standard protocols.

Reduced-intensity conditioning using TBI (8 Gy), fludarabine, cyclophosphamide and ATG in elderly CML patients provides excellent results especially when performed in the early course of the disease.

Allogeneic bone marrow or stem cell transplantation is a curative therapeutic option for chronic myelogenous leukemia. In order to decrease the toxicity of the procedure, the dosage of total body irradiation was reduced from 12 to 8 Gy and subsequently the dose of cyclophosphamide from 120 to 80 mg/kg. The purine analogue fludarabine, ATG, cyclosporine A and a short course of methotrexate were given for immune suppression. So far, 35 elderly CML patients with sibling and unrelated donors have been transplanted. Transplant-related mortality at day + 100 was 11%. After engraftment, all patients achieved a complete cytogenetic remission. Relapse occurred in 14% of the patients. The risk of relapse was significantly higher in those patients transplanted in second chronic or accelerated phase (P = 0.048). After a median follow-up of 30 months (range 12-62), 63% of the patients are alive. Those patients transplanted within the first year from diagnosis had an overall survival of 79% (P = 0.049), emphasizing the benefit of early transplantation. Stepwise reduction of conditioning intensity resulted in stable engraftment, low relapse rates and encouraging overall survival in this high-risk patient group.

Adoption of long-term cultures to evaluate the cryoprotective potential of trehalose for freezing hematopoietic stem cells.

Dimethylsulfoxide (DMSO), which is widely used as a cryoprotectant for hematopoietic stem cells (HSC), has considerable toxicity for both the thawed cells and the patient. The aim of this study was to evaluate the cryoprotective potential of trehalose in comparison to DMSO for human HSC. Human bone marrow (BM) and peripheral blood stem cells (PBSC) of volunteer donors were cryopreserved in the presence of different concentrations of trehalose with and without insulin, as well as with DMSO 10%. After thawing to 37 degrees C colony-forming unit (CFU) assays were performed. Long-term marrow-cultures (LTMC) were established and used for the detection of long-term culture-initiating cells (LTCIC). The total amount of CFUs detected was 104+/-134 (mean+/-s.d.) in DMSO-preserved cells and 179+/-34 in trehalose-protected cells. For LTMC the best feeder layer proved to be fresh human BM and the most useful concentration of trehalose was 0.5 M. Using these culture conditions we could detect after 5 weeks LTMC a total of 172+/-28 CFUs for trehalose-protected cells and 170+/-52 for DMSO-preserved cells. In conclusion, trehalose exerts a similar cryoprotective potential for hematopoietic progenitor and stem cells like DMSO and could possibly replace DMSO at least in part as cryoprotectant in the setting of hematopoietic cell transplantation.

ATG as part of the conditioning regimen reduces transplant-related mortality (TRM) and improves overall survival after unrelated stem cell transplantation in patients with chronic myelogenous leukemia (CML).

Matched unrelated donor transplants have an increased risk of severe graft-versus-host disease and transplant-related mortality (TRM). ATG has been introduced to decrease GvHD and to facilitate engraftment. We conducted a retrospective analysis of 333 patients with chronic myelogenous leukemia, who were treated with Fresenius ATG (n=145, average=90 mg/kg bw, range 40-90 mg/kg bw) or standard immunosuppression without ATG (n=188). Both groups were comparable regarding distribution of age, sex, HLA-matched vs mismatched donors. ATG Fresenius led to a faster leukocyte engraftment, decreased the incidence of acute GvHD and TRM (P=0.01 and P=0.03) and led to a significant better overall survival (70 vs 57%, P=0.03). We concluded that a prospective randomized study is needed to evaluate the definite role of ATG in hemopoietic stem cell transplantation.

Dose-dependent effects of in vivo antithymocyte globulin during conditioning for allogeneic bone marrow transplantation from unrelated donors in patients with chronic phase CML.

We conducted a dose-escalation study with antithymocyte globulin (ATG) in patients undergoing unrelated donor bone marrow transplantation (URD-BMT). This study analyzes the results for 97 patients with chronic myelogenous leukemia (CML) in first chronic phase. Median age was 36 years (16-51). In all, 40 patients were transplanted within 2 years after diagnosis and 57 later during disease. ATG-S (Fresenius) 20-120 mg/kg body weight (b.w.) was given prior to transplantation. A total of 31 patients received less than 60 mg/kg b.w. and 66 patients received 60 mg/kg b.w. or more. All patients except one were grafted with bone marrow, and graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporin A and methotrexate. Graft failure did occur in one patient. Grade II-IV acute GVHD developed in 56.7% and extensive chronic GVHD in 11.3% of the patients. The relapse rate was 13.4%. With a median follow-up of 5.8 years (1.5-12.1), 5-year disease-free and overall survival for all patients were 56 and 66%, and for patients transplanted within 2 years of diagnosis it was 72 and 82%. A lower dose of ATG was a significant risk factor for poor outcome. In summary, URD-BMT remains an excellent treatment option for patients with early phase CML, if a sufficient amount of ATG is included in the preparative regimen.

[Dose-reduced conditioning before allogeneic stem cell transplantation: principles, clinical protocols and preliminary results]. / Dosisreduzierte Konditionierung vor allogener Stammzelltransplantation - Grundprinzipien, klinische Protokolle und erste Ergebnisse

BACKGROUND AND OBJECTIVE: In the treatment of leukemia by stem cell transplantation, the immunological effects of allogeneic T-lymphocytes presumably play a greater part than high-dosage total-body irradiation (TBI) and chemotherapy. Using this immunological effect, attempts are currently being made to reduce the dosage of pre-treatment that is toxic to stem cell, such as TBI, thereby making transplantation available for a larger group of patients at high risk for transplantation. This study presents preliminary results of three current studies of this approach. PATIENTS AND METHODS: Elderly patients with chronic myeloid leukemia (CML) have an increased transplantation risk. They were conditioned with TBI that was reduced stepwise (n = 27). Patients with advanced and refractory myeloid leukemia were treated with chemotherapy and dose-reduced TBI (FLAMSA protocol; n = 54). In patients with multiple myeloma, autologous transplantation with high-dose chemotherapy preceded allogeneic transplantation possible after dose-reduced conditioning (Tandem protocol; n = 6). RESULTS: All three protocols of TBI gave results that were not worse than those of previous studies. Relapse ocurred not more frequently in patients with CML. In patients with high-risk AML the FLAMSA protocol gave better results. Autologous-allogeneic tandem transplantation was well tolerated and led to a good response in all patients. CONCLUSION: Allogeneic transplantation after dose-reduced conditioning opens up new possibilities with respect to widening indications for transplantation and improving results in hematological diseases with previously unsatisfactory treatment.

[Allogeneic transplantation in malignant lymphoma]. / Allogene Transplantation maligner Lymphome.

INTRODUCTION: Allogeneic transplantation of bone marrow and peripheral blood stem cells is a frequently discussed therapeutic option in the treatment of malignant lymphoma. By analysing the results of our own transplant program in patients with advanced lymphoma we tried to evaluate indications for allogeneic transplantations. METHODS: Data from lymphoma patients treated at the Klinikum Grosshadern between 1985 and 2001 were analysed retrospectively. RESULTS: 56 patients were included. 24 patients had low grade Non-Hogdkin's lymphoma (NHL) (follicular lymphoma: n = 8, mantle cell lymphoma: n = 6) or chronic lymphocytic leukemia (CLL: n = 10), 16 patients had high grade NHL (immunoblastic/lymphoblastic: n = 5; large cell/diffuse: n = 5) and 8 patients suffered from Hodgkins's disease. Median age was 41 years, 34 patients were transplanted from an HLA-identical sibling, 19 from an HLA-id. unrelated donor and three from an HLA-mismatched related donor. 30 patients received bone marrow and 26 peripheral blood stem cells. 22 pat. were treated with an intensive 12 Gy TBI containing conditioning regimen, whereas 34 patients were treated with a dose-intensity reduced conditioning procedere. 25 patients are alive between 2 month and 15 years after transplantation. Overall survival after 2 years is 48 % for patients with low grade NHL (incl. CLL), 9.3 % for patients with high grade lymphoma and 25 % for patients with Hodgkin's disease. 1-year-transplant-related mortality (TRM) was 33.9 % in all patients. Dose-intensity-reduced conditioning was not able to reduce TRM. CONCLUSIONS: Allogeneic bone marrow or stem cell transplantation is able to induce long lasting complete remissions in patients with heavily pretreated malignant lymphoma. Results of allogeneic transplantation are encouraging in patients with follicular and other low grade lymphoma. However transplant-related toxicity is high. At present the impact of reducing the intensity of conditioning is not yet clear.