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.

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.

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.

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.

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.

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.

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.

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]

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]

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.

Adoptive allogeneic immunotherapy--history and future perspectives

For more than 30 yrs allogeneic hematopoietic stem cell transplantations have been successfully performed in patients with hematologic malignancies and bone marrow aplasia. Over the years the field of transplantation has changed dramatically. More and more unrelated donors became available, regimens for haploidentical transplantations were introduced and G-CSF mobilized peripheral blood stem cells and fetal cells from umbilical cord became available as alternate sources of hematopoietic stem cells. However, especially the introduction of donor lymphocyte infusions (DLI) for the successful treatment of leukemic relapses after allogeneic stem cell transplantations improved our understanding of transplantation immunology and opened amazing perspectives in allogeneic transplantation. It was long believed, that myeloablative therapy with high-dose chemotherapy and total body irradiation (TBI) are the sole antileukemic principles in allogeneic transplantations. But by now it became clear, that donor lymphocytes exert a very potent antileukemic effect, now referred as the graft-versus-leukemia (GVL) or graft-versus-malignancy (GVM) reaction. The efficacy of DLI in controlling leukemic relapses suggests that myeloablative therapy is not essential for long-term disease control. By exploiting the GVL or GVM reaction more intensively the role of chemotherapy and TBI is changing to immunosuppression. Sufficient immunosuppression to allow grafting, however, can be achieved with much lower doses as those which have been used in conventional transplants. Therefore allogeneic transplants have become also available for the elderly or for patients with concurrent medical conditions, which would have excluded them from conventional transplants. Moreover, this allogeneic transplantation strategy with reduced intensity conditioning is now also under investigation in patients with susceptible solid tumors and autoimmune diseases. However, one major obstacle in allogeneic transplantations, namely the graft-versus-host disease (GVHD), remains to be solved.

Quality assurance in RT-PCR-based BCR/ABL diagnostics--results of an interlaboratory test and a standardization approach

Here we describe the results of an interlaboratory test for RT-PCR-based BCR/ABL analysis. The test was organized in two parts. The number of participating laboratories in the first and second part was 27 and 20, respectively. In the first part samples containing various concentrations of plasmids with the ela2, b2a2 or b3a2 BCR/ABL transcripts were analyzed by PCR. In the second part of the test, cell samples containing various concentrations of BCR/ABL-positive cells were analyzed by RT-PCR. Overall PCR sensitivity was sufficient in approximately 90% of the tests, but a significant number of false positive results were obtained. There were significant differences in sensitivity in the cell-based analysis between the various participants. The results are discussed, and proposals are made regarding the choice of primers, controls, conditions for RNA extraction and reverse transcription.

Human parvovirus B19-associated disease in bone marrow transplantation

Human parvovirus B19 can persist in immunocompromised patients and may produce severe clinical illness. In this retrospective study the incidence of B19-associated infections in bone marrow transplant patients was investigated. During 1 year 60 patients received bone marrow grafts (eight autografts and 52 allogeneic transplantations). In case of early onset, atypical or steroid-resistant erythrodermia the patients' blood and/or tissue specimens were screened for B19 infection by polymerase chain reaction (PCR). Additionally, specimens of patients with severe organ failure were tested. A total of 64 PCRs was performed in 27 patients. Seven patients with erythrodermia and one with vulvovaginitis proved to be PCR positive. In patients with organ failure B19 DNA was detected in the myocardium and liver. The incidence of B19 infections in this cohort was 15% and the B19-associated mortality rate 7%. In conclusion, parvovirus B19-associated infections may be more common in immunocompromised patients than previously anticipated.

Bcr-abl protein detection in peripheral blood mononuclear cells for follow-up of chronic myelogenous leukaemia patients

We have assessed the value of p210 protein detection in peripheral blood cells for follow-up of chronic myelogenous leukaemia (CML) patients. Quantification was achieved by comparing the relative intensities of the p210 bands with those of the normal abl protein (p145). Serial dilution of Ph-positive K562 cells with Ph-negative HL60 or KG1 cells revealed a linear correlation between the p210/p145 ratio and the number of Ph-positive cells (r = 0.998; p < 0.001) with a sensitivity of detecting less than 1% Ph-positive cells in 5 x 10(6) cells. Ninety-six consecutive patients were enrolled in the study and a total of 155 Western blot analyses have been performed and compared to chromosomal analyses of bone marrow. Parallel RT-PCR analyses have been performed on 99 occasions. All patients with positive cytogenetic findings also probed positive for p210. In 23 instances p210 was detectable despite negative chromosomal analysis. In 16 samples these results were confirmed by RT-PCR. In patients with partial cytogenetic remission (n = 26) the results of the p210 assay correlated significantly with the percentage of Ph-positive metaphases (r = 0.69; p < 0.001). In conclusion, monitoring of CML patients by quantification of the bcr-abl protein is a feasible and sensitive alternative to chromosomal analysis of bone marrow.

Neurological and neuroradiological findings in long-term survivors of allogeneic bone marrow transplantation

The aim of this study was to assess neurological, neuropsychological, and neuroradiological findings in long-term survivors of allogeneic bone marrow transplantation (BMT) who were recruited from a hematological outpatient clinic. In addition, risk factors for the development of late neurological complications were identified. In contrast to previous studies on autopsied patients, our study design provoked a bias away from increased neurological sequelae, because patients with early complications after BMT were excluded. Fifty-nine allogeneic patients and 7 autologous BMT patients underwent clinical examination, short neuropsychological testing, and cranial magnetic resonance imaging (MRI) 34 +/- 26 months after BMT. The pathological results of the neurological examination (abnormal 64%) and the MRI examination (white matter lesions, 54%; atrophy, 11%) were associated with the occurrence of chronic graft-versus-host disease (GvHD) evolving from acute GvHD, with corticosteroid therapy and with cyclosporine medication. Neuropsychological impairment (cognitive deficits, 37%) was associated with long-term cyclosporine medication and age. No influence of pre-BMT disease, BMT donor status, or the conditioning regimen was found. These results suggest that the frequent neurological abnormalities in long-term survivors of allogeneic BMT are associated with chronic GvHD and with the resulting immunosuppression as major risk factors.

[Previous activation of platelets during storage: possible causes]

Stored single-donor platelets are characterized by a progressive cell activation. The data presented indicate that activation of plasma coagulation and complement system could contribute to this storage lesion process.

Levels of the terminal complement complex, C3a-desArg and C1-inhibitor in adult patients with capillary leak syndrome following bone marrow transplantation

Capillary leak syndrome (CLS) is a severe complication after bone marrow transplantation (BMT). To investigate whether there is a pathogenetic role of the complement system, we monitored the levels of the terminal complement complex C5b-9 (TCC) and C3a-desArg as indicators of an activation of the complement system and the inhibitor of the classical pathway of the complement cascade, C1 inhibitor (C1-INH), in 48 bone marrow transplant recipients from 1 week before to 5 weeks after transplantation. Capillary leak syndrome developed in 7 out of 48 patients between days 1 and 12 after BMT. Complement activation as indicated by TCC levels was more pronounced in patients with CLS (n = 7) from day -8 to +28 (p < 0.05; day -1) and the elevation of TCC levels lasted longer in CLS patients (peak day 21) than in patients without this complication (peak day 7). Mean C3a-desArg levels were highest in patients with CLS reaching a peak at day 7. During the early posttransplant period a significant elevation of C1-INH levels (p < 0.01 and p < 0.05 respectively) compared with baseline levels (day -8) was found in patients with and without CLS, which was more pronounced in those patients with CLS (p < 0.05). Although we could not observe an absolute C1-INH deficiency as compared to healthy individuals our data support the presence of a relative deficiency of the inhibitor which might explain the reported beneficial effects of C1-INH substitution in BMT related CLS.

Cryopreservation of human platelets with dimethyl sulfoxide: changes in biochemistry and cell function

BACKGROUND

The shelf life of liquid-stored platelet concentrates is limited to 5 days. Therefore, much work has been carried out in an attempt to establish the optimum method for cryopreservation. Among the various cryoprotectants, dimethyl sulfoxide (DMSO) has been shown to be the most effective. However, DMSO-frozen platelets are characterized by a number of cell lesions. This report describes metabolic and functional changes that should give rise to some concern about the functional integrity of these cells.

STUDY DESIGN AND METHODS

Single-donor platelet concentrates were frozen in liquid nitrogen by use of DMSO (5%). After thawing, the cells were washed and resuspended in autologous plasma. Before, during, and after the freezing process, samples for analysis of metabolic measures (e.g., pH; calcium, potassium, and lactate dehydrogenase concentrations; plasma complement factors) and functional measures (e.g., aggregometry, in vitro bleeding time, alpha-granule membrane protein-140 expression) were taken.

RESULTS

Mean platelet volume increases during the deep-freezing process. Potassium, calcium, and lactate dehydrogenase are released from the intracellular space to the extracellular space. A strong activation of complement, which is mainly due to the addition of DMSO, is observed. Platelets become activated as indicated by the expression of alpha-granule membrane protein-140. Accordingly, decreased platelet function can be observed.

CONCLUSION

DMSO-frozen platelets are characterized by several metabolic and functional changes. Although these cells have been shown to exert hemostatic effects in vivo, it is conceivable that those effects could be improved by further development of platelet-freezing techniques.

Modulation of acute graft-versus-host-disease after allogeneic bone marrow transplantation by tumor necrosis factor alpha (TNF alpha) release in the course of pretransplant conditioning: role of conditioning regimens and prophylactic application of a monoclonal antibody neutralizing human TNF alpha (MAK 195F)

Contribution of host-related cytokine release in the course of pretransplant conditioning to early tissue damage and induction of acute graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT) has been shown in experimental models. We performed a clinical phase I/II trial applying a monoclonal antibody neutralizing human tumor necrosis alpha (TNF alpha) during pretransplant conditioning as additional prophylaxis in high-risk patients admitted to allogeneic BMT; TNF alpha serum levels and clinical courses in 21 patients receiving anti-TNF alpha prophylaxis were compared with data from 22 historical controls. Absence of significant release of TNF alpha in the period of busulphan (BUS) treatment, but significant induction of TNF alpha by total body irradiation (TBI) and cyclophosphamide (CY) conditioning were correlated with significantly earlier onset of acute GVHD in patients receiving TBI/CY regimens as compared with BUS/CY-treated patients. Prophylactic application of monoclonal anti-TNF alpha seemed to postpone onset of acute GVHD from day 15 to day 25 (P < .05) after TBI/CY and from day 33 to day 53 after BUS/CY (P < .10) conditioning. Application of monoclonal anti-TNF alpha in low and intermediate doses was safe and not associated with an increased incidence of infectious or hematologic complications. Thus, our data provide indirect and direct evidence for involvement of conditioning-related cytokine release in induction of early acute GVHD in the clinical setting and support further investigation of this novel approach in randomized trials.

Complement activation during storage of single-donor platelet concentrates

Single-donor platelets are stored up to 5 days prior to transfusion. Since contact of plasma to plastic surfaces may lead to complement activation, we investigated whether there is any increase in the complement factors C3a, C4a and C5a in routinely stored single-donor platelet concentrates. C3a levels increased about 40-fold during a 7-day storage. C4a levels also increased with storage time but to a lesser extent. By contrast, C5a levels remained stable throughout this period. ADP- and collagen-induced aggregation was impaired after storage of platelets, indicating severe functional injury. In platelet-poor plasma stored under identical conditions a comparable increase in C3a and C4a concentrations was observed. The loss of platelet function during storage might at least in part be due to the excessive anaphylatoxin concentrations observed.

Inhibition of cyclosporin A/FK506 resistant, lymphokine-induced T-cell activation by phenothiazine derivatives

Earlier studies from our laboratory have demonstrated that phenothiazine derivatives are capable of inhibiting mitogen-induced activation of human T-cells and thymocytes. Similar to cyclosporin A, phenothiazine derivatives exert these inhibitory effects by decreasing the accumulation of lymphokine-specific mRNA. However, proliferation of T-cell blasts and of unfractionated human thymocytes can also be induced by interleukin 2. Since activation of T-cells via the interleukin 2 receptor seems to be resistant to the action of cyclosporin A, the present study was designed to investigate whether lymphokine-induced activation could be inhibited by phenothiazine derivatives. The effects of the phenothiazine derivatives chlorpromazine and/or fluphenazine have been studied and compared to the action of cyclosporin A and FK506 in human thymocytes, human T-cell blasts and in the human T-cell line H33-HJ JA1, which is an interleukin 2 producing cell line derived from Jurkat cells. As evidenced by the incorporation of [3H]-thymidine, cyclosporin A (1 microgram/ml) and FK506 (100 ng/ml) have no or only marginal inhibitory capacity on interleukin 2-induced proliferation in all T-cell systems tested. By contrast, phenothiazine derivatives (fluphenazine > chlorpromazine) exert a dose-dependent inhibition of the activation of these cells in pharmacologically relevant micromolar concentrations. Similar results were obtained by measuring the production of interferon-gamma in the supernatants of interleukin 2-induced human thymocytes. Our results suggest that the use of phenothiazines might be helpful in immunosuppressive regimens.

Growth inhibition of human leukemic cell lines by the phenothiazine derivative fluphenazine

The effect of the phenothiazine derivative fluphenazine has been studied in the human leukemic T-cell line H33-HJ JA1, which is an Interleukin-2 (IL-2) producing cell line derived from Jurkat cells. This cell line shows a highly proliferative activity in response to the autocrine produced IL-2. The phenothiazine fluphenazine (1-10 microM) inhibited this proliferation in a dose-dependent manner, as evidenced by the incorporation of (3H)-Thymidine. In analogy, growth inhibition by fluphenazine has been investigated in the human myeloblastic HL-60 cell line. The spontaneous growth of this cell line was also inhibited by fluphenazine at pharmacologically relevant micromolar concentrations. These results suggest that the use of phenothiazines might be helpful in antileukemic regimens.

Storage of single-donor platelet concentrates: metabolic and functional changes

During the last decade, the trend toward intensifying chemotherapeutic regimens in patients with hematologic malignancies rapidly increased the demand for single-donor platelet concentrates (PCs). The logistics of such supply, however, necessitated the storage of these blood components prior to transfusion. Today, most blood centers use di(2-ethylhexyl)phthalate-free blood bags, which are assumed to allow a storage period of up to 5 days. This report describes biochemical and functional changes of stored single-donor PCs, which may influence the expected quality of PCs. The acid-base status is characterized by an initial respiratory alkalosis compensated by a metabolic acidosis. Changes in extracellular electrolyte, lactate dehydrogenase, glucose, lactate, elastase, and complement levels, as well as in the release of alpha granule content and the initial activation of plasma coagulation, are demonstrated. These changes result in a functional impairment of stored PCs as reflected by thromboxane and serotonin release reaction and by aggregation and in vitro bleeding time studies. In contrast, in vivo recovery and survival rates have been reported to be unaffected. Whether the good recovery and survival rates are caused by a rejuvenescence of stored PCs in vivo or are due to injured circulating platelets has not yet been proven.

Lusorian artery lesion as rare cause of severe upper gastrointestinal tract bleeding

A patient in an intensive care unit experienced severe esophageal bleeding caused by erosion of a lusorian artery. The lusorian artery is a rare variant of the right subclavian artery. It originates in the descending aortic arch and crosses behind the esophagus to the right, sometimes generating esophageal compression. The patient's condition required respirator therapy and placement of a duodenal tube. At the point of crossing over of the lusorian artery and the esophagus, the duodenal tube caused esophageal necrosis, leading to erosion of the lusorian artery. This resulted in extensive esophageal bleeding, which at last required surgical intervention. To attain proper treatment and to avoid unnecessary diagnostic and therapeutic approaches, a lusorian artery lesion has to be included in the differential diagnosis of upper gastrointestinal bleeding.

Effects of leukocyte depletion on the formation of anaphylatoxins in stored whole blood

As reported earlier, factors of the complement cascade get activated in CPD-A1-stabilized whole blood. As early as after 10 days of storage under normal blood bank conditions the elevations of the concentrations of C3a-desArg and C4a-des-Arg were highly significant. By contrast, the concentration of the C3 activator complex C4b2b remained unchanged even after 3 weeks of storage. Leukocyte depletion partially inhibited the activation of C4 but had no effect on C3a concentrations. Therefore, cleavage of C4 during storage of whole blood seems to be partially leukocyte-dependent, whereas the activation of C3 is possibly due to the activation of the alternate pathway of the complement system by contact of blood to plastic surfaces. Even through the radioimmunologically measured C3a might be inactive as an anaphylatoxin, these observations are of clinical importance since the inactivated C3a-desArg still possesses biological activities such as activation of platelets which may lead to hypercoagulability and thrombosis.

Complement activation during storage of blood under normal blood bank conditions. Effects of proteinase inhibitors and leukocyte depletion

During storage of CPD-A1 preserved whole blood factors of the complement cascade become activated, as evidenced by a rapid increase in the concentrations of C3a-desArg and C4a-desArg. After 10 to 14 days of whole blood storage, the elevations of C3a and C4a levels were highly significant. This increase was paralleled by an increase in the concentration of the lysosomal proteinase elastase from polymorphonuclear (PMN) granulocytes. By contrast, the concentration of the C3 activator complex C4b2b remained unchanged even after 3 weeks of storage. The supplementation of the anticoagulant CPD-A1 with the polyvalent-proteinase-inhibitor aprotinin and the specific elastase-inhibitor eglin C failed to inhibit complement activation, whereas leukocyte depletion could partially abolish the increase of the concentration of C4a, but had no effect on C3a concentrations. These observations support the notion that cleavage of C4 during storage of whole blood is partially leukocyte dependent, whereas the activation of C3 is possibly caused by the activation of the alternate pathway of the complement system by contact of plasma with plastic surfaces.

Intravenous anti-D gammaglobulin for the prevention of rhesus isoimmunization caused by platelet transfusions in patients with malignant diseases

Previous studies of sensitization to RhD by RhD-positive platelet transfusions in RhD-negative cancer patients have shown different frequencies of alloimmunization (max. 19%). We studied 37 RhD-negative patients who received RhD-incompatible platelet transfusions and simultaneously anti-D-immune globulin. We provide evidence that in this setting RhD-prophylaxis is highly effective in preventing alloimmunization due to RhD antigen, since none of the patients studied developed anti-D. Detection of other red blood cell antibodies than anti-D proves the possibility of immunization in these patients. Prevention of isoimmunization in patients with malignant diseases is recommended especially in young females, since an increasing number of patients are having successful pregnancies, despite prior or even during cytotoxic therapy.

Tumor necrosis factor: an update on basic research and clinical applications

Tumor necrosis factor is one of the recently cloned cytokines with pleiotropic effects on normal and malignant cells. Our knowledge about the scope of cells producing or responding to this cytokine has enormously expanded. In critically ill patients with acute hepatic failure, acute graft-versus-host disease, or septic shock, circulating tumor necrosis factor can be measured and useful prognostic correlations do exist. Despite promising in vitro results, early clinical trials with tumor necrosis factor for the treatment of cancer have failed thus far to reveal major antineoplastic activity in cancer patients. However, more clinical trials are necessary, since different routes of administration and combinations with other cytokines may lead to favorable results.

Immunoregulation and production of tumor necrosis factor alpha by human thymocytes

We have provided evidence that tumor necrosis factor alpha (TNF-alpha) enhances the proliferation and the state of activation of human thymocytes cultured with concanavalin A or interleukin 2 (IL-2), as evidenced by an increase in the expression of the c-myc gene and the gene of the IL-2 receptor (alpha-chain, Tac antigen) and by the expression of Tac antigen on the cell surface. Our observations suggest that TNF-alpha interacts with IL-2 and with another factor(s) which is induced in the course of activation by concanavalin A, since the immunosuppressant drug cyclosporin A-, which inhibits thymocyte activation, prevents the effect of TNF-alpha on thymocytes activated with concanavalin A, whereas anti-Tac, which prevents the binding of IL-2 to its receptor without affecting the production of IL-2 or the expression of IL-2-specific mRNA, inhibits proliferation only partially. By contrast, anti-Tac inhibits the response to TNF-alpha of thymocytes induced with IL-2 completely. These observations show that TNF-alpha exerts a potentially important immunoregulatory effect in synergy with IL-2 on thymocytes, which could contribute to tumor rejection. In addition, we show that activated human thymocytes express the TNF-alpha gene and that the expression of this gene is inhibited by cyclosporin A and dexamethasone.

Rh antibodies against the pretransplant red cells following Rh-incompatible bone marrow transplantation

A 22-year-old, blood group O, Rh-positive (R2r) man received bone marrow from his blood group A, Rh-negative (rr), HLA-identical sister for treatment of acute lymphocytic leukemia. The patient's pretransplantation serum contained anti-A in a low concentration; therefore, plasmapheresis was not done prior to transfusion of bone marrow. To prevent graft-versus-host disease, bone marrow was incubated with absorbed rabbit antithymocyte globulin prior to infusion, and the patient was treated with methotrexate in the posttransplantation period. After transplantation, the patient received 6 units of group O, Rh-negative (rr) packed red cells from random donors and 6 units of platelets from the marrow donor. Three months after transplantation, 0.5 percent of his red cells were still of the host's type (group O, Rh-positive), as detected by immunofluorescence technique in blood smears. Four months after transplantation, three different Rh antibodies--anti-D, -E, and -G--were detected. Since the patient received only Rh-negative red cell transfusions, it is concluded that he was immunized to his original red cells.