A prospective multicenter phase II study of oral and i.v. vinorelbine plus trastuzumab as first-line therapy in HER2-overexpressing metastatic breast cancer.

BACKGROUND: To evaluate the efficacy and safety of oral and i.v. vinorelbine plus trastuzumab as first-line regimen in a patient-convenient application for human epidermal growth factor receptor 2 (HER2)-overexpressing patients with metastatic breast cancer. PATIENTS AND METHODS: Forty-two women were enrolled in a multicenter study. The patients received i.v. vinorelbine at a dose of 25 mg/m(2) on day 1 followed by oral vinorelbine at a dose of 60 mg/m(2) on days 8 and 15 in a 3-week cycle. Standard dose trastuzumab was given at 3-week intervals. RESULTS: Complete response was observed in 7 patients (18.9%) and partial response in 19 patients (51.4%), for an overall response rate of 70.3% [95% confidence interval (CI) 53.0-84.1]. The disease control rate reached 91.9% (95% CI 78.1-98.3). The median time to progression was 9.3 months, while median overall survival reached 35.6 months. Hematological and non-hematological toxic effects were acceptable with grade 3-4 leukopenia of 14% and neutropenia of 38%; cardiac toxicity did not reach the level of clinical relevance. CONCLUSION: The combination of i.v. and oral vinorelbine plus trastuzumab demonstrates high activity and good tolerability in first-line treatment of HER2-overexpressing metastatic breast cancer. In addition, it offers convenience for the patients with only one i.v. treatment every 3 weeks.

Apheresis platelet concentrates contain platelet-derived and endothelial cell-derived microparticles.

BACKGROUND AND OBJECTIVES: Microparticles (MP) are membrane vesicles with thrombogenic and immunomodulatory properties. We determined MP subgroups from resting platelets, activated platelets and endothelial cells in donors and apheresis platelet concentrates (PC). MATERIAL AND METHODS: MP were double stained with annexin V and CD61 (platelet-derived MP; PMP), P-selectin or CD63 (MP from activated platelets) and CD144 plus E-selectin (endothelial cell-derived MP; EMP) and detected by flow cytometry in platelet donors (n=36) and apheresis PC (n=11; Trima™). RESULTS: PC contained MP, mainly from resting platelets [93% (90-95)], and minor fractions of PMP from activated platelets [P-selectin(+) or CD63(+); 4·8% (3·2-7·7) and 2·6% (2·0-4·0)]. Compared to donors, levels of annexin V+ MP, PMP, P-selectin(+) and CD63(+) MP were 1·7-, 2·3-, 8·6- and 3·1-fold higher in PC (all P<0·05). During storage (1-5 days), levels of annexin V+ MP and PMP did not increase, although small increases in the fraction of P-selectin(+) or CD63(+) MP occurred (both P<0·05). PC also contained EMP, which were 2·6- to 3·7-fold enriched in PC compared to donors (P<0·05). CONCLUSIONS: Transfusion of apheresis PC also results in transfusion of HLA-carrying PMP and EMP. This might counteract the aim of reducing transfused HLA load by leucodepletion. The increases in PMP exposing P-selectin or CD63 reflect mild platelet activation during storage. We conclude that in leucodepleted platelet apheresis using fluidized particle bed technology, MP are harvested mainly from the donor by apheresis. Improvement in apheresis technology might reduce MP load.

Kinetics of dendritic cell chimerism and T cell chimerism in allogeneic hematopoietic stem cell recipients.

Dendritic cells (DC) as potent antigen-presenting cells (APC) and T cells as effector cells play an essential role in the pathophysiology of both graft-versus-host (GvH) and graft-versus-leukemia (GvL) reactions after transplantation. Therefore, we determined the kinetics of DC and T-cell chimerism establishment after allogeneic hematopoietic cell transplantation (AHCT) in a group of 144 patients, using fluorescence-activated cell sorting (FACS) or magnetic cell sorting (MACS) followed by FISH or STR-PCR analysis for chimerism evaluation. In all, three cell lines investigated (CD3(+) T cells, CD11c(+) DC1 and CD123(+) DC2), we found a rapid and consistent establishment of complete donor chimerism (CDC) in over 70% of all patients during the first 6 weeks after AHCT. The rate of patients with CDC increased significantly over time within the first year after transplantation. A related donor (P=0.004) as well as an underlying lymphatic leukemia (P=0.03) were found to be significantly associated with development of MC in T cells. No significant correlation between DC or T cell chimerism and GvHD or relapse was detected. Our results thus demonstrate a fast and stable CDC in DC1, DC2 and T cells after AHCT that continuously increases over time in nearly all patients.

Protein C and procollagen III peptide levels in patients with hepatic dysfunction after allogeneic hematopoietic stem cell transplantation.

Veno-occlusive disease (VOD) is one of the most serious complications following hematopoietic stem cell transplantation (HSCT) and is associated with a high mortality. We conducted a large trial on the clinical significance of protein C (PC) and procollagen III peptide (PNPIII) levels, which have been described as possible diagnostic markers of VOD. In total, 350 patients undergoing allogeneic HSCT were included. PC and PNPIII levels were analyzed prior to conditioning and weekly until 8 weeks after the HSCT. Signs of VOD and other transplantation-related complications (graft-versus-host disease (GVHD), toxicity, microangiopathic hemolytic anemia, infection) were recorded weekly throughout the trial. Patients showed a significant drop of the PC levels in VOD (70.3 vs 96.3%, P<0.001) and with increasing severity of aGVHD. Steroids increased the PC levels (69.4% vs 109.4%, P<0.001). The highest PNPIII levels were registered in patients with VOD (mean 6.3 IU/ml). Patients with aGVHD showed an elevation of PNPIII, especially patients with hepatic aGVHD. PC levels during conditioning do not predict VOD (98.5 vs 76.5%, NS). Although PC and PNPIII may play a role in the pathogenesis of VOD they cannot discriminate between complications with jaundice and are only of limited help in the differential diagnosis of VOD.

Platelet flow cytometric findings in patients undergoing conditioning therapy for allogeneic hematopoietic stem cell transplantation.

The conditioning regimen preceding hematopoietic stem cell transplantation (HSCT) causes a rapid decrease in the platelet count and signs of disseminated intravascular coagulation, possibly indicating platelet activation. As impacts during the conditioning regimen may predict later transplantation-associated complications, we investigated changes in platelet membrane glycoproteins (GP) and the liberation of microparticles. Platelet receptors and granules of 49 patients undergoing HSCT were evaluated by flow cytometric analysis before and after the different phases of the conditioning regimen [chemotherapy, total body irradiation (TBI), therapy with antithymocyte globulin (ATG)] and final transplantation. Following chemotherapy a high surface expression of CD62P, a low mepacrine staining, and a reduced surface expression of CD42b (part of the GP Ib/V/IX complex) were found, indicating an irreversible activation of platelets. In addition, elevated levels of circulating microparticles were observed, which may reinforce the thrombosis risk in these patients. Treatment with ATG leads to an elevated surface expression of PAC-1 epitopes, which are neoepitopes appearing after activation of GP IIb/IIIa. However, a significant degranulation was not detectable, which may be the consequence of inhibitory influences on platelets during ATG-induced cytokine release syndrome. TBI and transplantation itself had no influence on platelets. This study was able to demonstrate activating effects on platelets by certain phases of the conditioning regimen in patients receiving HSCT. Chemotherapy, in particular, leads to a strong and irreversible platelet activation and a generation of microparticles, which may cause an increased thrombosis risk. Our findings underline the impact of platelets on the pathogenesis of hemostatic complications during HSCT.

The impact of antithymocyte globulin on short-term toxicity after allogeneic stem cell transplantation.

Antithymocyte globulin (ATG) is commonly used in allogeneic haematopoietic stem cell transplantation (HSCT). Little information is available, however, as to the optimal protocol for use and the side-effects occurring if ATG is administered in high daily doses (10-30 mg/kg). We report our experience with ATG Fresenius (ATG-F) in conditioning for allogeneic HSCT. During a period of 3 days, 47 patients received doses between 10 and 30 mg/kg either over 4 h preceded by 1-1.5 mg/kg prednisolone 30 min before the start of ATG-F (protocol A) or alternatively, over 12 h with 3-4 mg/kg prednisolone being administered before and 6 h after start of ATG (protocol B). During treatment with ATG-F, the side-effects observed included inflammation, disseminated intravascular coagulation, hyperdynamic circulation and renal dysfunction. Although these complications caused substantial morbidity, they were reversible within a few days. Side-effects were significantly more severe in patients treated according to protocol A than in those treated according to protocol B. As prolonged infusion of ATG-F does not reduce T cell clearance due to the long half-life of ATG-F, and since less cytokine release during conditioning might have beneficial long-term effects, we recommend administering ATG-F over 12 h preceded by high-dose steroid treatment.

Flow cytometric findings in platelets of patients following allogeneic hematopoietic stem cell transplantation.

Following allogeneic hematopoietic stem cell transplantation (HSCT) patients may have an increased bleeding tendency in spite of a normal platelet count. Moreover, an association between chronic graft-versus-host disease (cGVHD) and a thrombophilic state has been observed. Platelet receptors and granules from 27 patients following HSCT (13 without cGVHD, 14 with cGVHD) were evaluated by flow cytometric analysis and compared to 62 healthy controls. Platelets from HSCT patients stained weakly with mepacrine indicating a reduced content of dense bodies, whereas no significant degranulation reaction of alpha granules and lysosomes was detectable. In addition, a lower surface expression of GP Ia/IIa was observed, indicating an acquired thrombocytopathy. The surface receptors are activated in HSCT patients, which could be seen by the lower surface expression of GP Ib internalized during the activation process and elevated levels of LIBS-1 and PAC-1 antibody binding. Patients with cGVHD had a seven-fold increased ratio of microparticles. This study demonstrates platelet receptor and granule defects in patients following HSCT. The key role of platelets in HSCT-associated hemostatic disorders is underscored by the high levels of circulating microparticles in cGvHD patients which might explain the thrombophilic state in these patients.

Levels of insulin-like growth factor after stem cell transplantation.

Some cytokines, i.e. tumor necrosis factor-, interleukin-6 and soluble interleukin-2 receptors are associated with complications of stem cell transplantation. Insulin-like growth factors (IGFs) are a family of peptides essential for the proliferation of normal and malignant cells. Recently increased levels of IGFs have been associated with the development of malignant tumors. In this communication we report on 96 measurements of insulin-like growth factor-I (IGF-1), insulin-like growth factor-II (IGF-2), and insulin-like growth factor-binding protein-3 (IGFBP-3) performed in 19 patients following stem cell transplants. Seventeen patients had allogeneic and 2 patients autologous transplants. Most IGF determinations were made at days 0, 7, 14, 21 and 28, some at other time points. The baseline values (day 0) of IGF-1 and IGFBP-3 were not different from controls. IGF-2 values were slightly lower than controls. Following transplantation, a consistent increase of IGF-1 was observed in 9/16 patients at days 7 and 14. Later the values decreased again. IGF-2 and IGFBP-3 did not change significantly after transplantation. No direct correlation could be established with the severity of graft-versus-host disease, levels of interleukin-6 and the time to hematopoietic recovery. A potential relevance of IGFs following stem cell transplantation may be the early diagnosis of liver damage and the development of second malignancies. More studies are necessary to investigate the pathophysiology and the clinical relevance of the increase of IGF-1 following stem cell transplantation.

The relevance of plasminogen activator inhibitor 1 (PAI-1) as a marker for the diagnosis of hepatic veno-occlusive disease in patients after bone marrow transplantation.

Hepatic veno-occlusive disease (VOD) is the third most important fatal complication in allogeneic bone marrow transplantation (BMT), the second most significant one in the autologous setting and the most severe of all the regimen related toxicities. A growing number of VOD cases has to be expected due to the increasing number of high dose chemotherapies given with consecutive stem cell transplantation in patients with solid tumors. Confirmation of the diagnosis of VOD by biopsy is associated with a high risk of severe bleeding complications and, unfortunately, until now reliable laboratory markers have not as yet been established. Recently, plasminogen activator inhibitor 1 (PAI-1), the main inhibitor of the fibrinolytic system, has been found to be significantly elevated in VOD patients probably reflecting hypofibrinolysis in these patients. Furthermore, PAI-1 was able to distinguish between patients with VOD and those with hyperbilirubinemia after BMT caused by graft-versus-host-disease (GVHD) or toxic effects, in which cases the PAI-1 levels were mostly within the normal range. In this overview we summarize the data strongly indicating that PAI-1 is a useful marker for the diagnosis of VOD and helps in the differential diagnosis of hyperbilirubinemia after BMT.

[Thrombophilia caused by congenital disorders of blood coagulation]. / Thromboseneigung durch angeborene Störungen der Blutgerinnung.

Today, more than 40% of all patients who develop a thrombosis are found to have inherited thrombophilia. The most common cause of this is APC resistance, which can usually be traced back to factor V-Leiden. In the commonly heterozygous patients the risk of thrombosis is increased about 7-fold (life-long risk of thrombosis 10 to 15%). In most cases, however, additional thrombogenic stimuli are required (oral contraception, pregnancy, surgery, immobilization). In combination with oral contraceptives, the risk is increased roughly 30-fold. In contrast, APC resistance does not present an increased risk for thrombosis in the arterial system (myocardial infarction, stroke). Four further inherited or acquired disorders of the hemostatic system are known: prothrombin dimorphism, antithrombin, protein C and protein S deficiencies. Prothrombin dimorphism, the second most common form of inherited thrombophilia, has been known only for the past two years and elevates the risk of thrombosis only to a moderate degree. Today, a search for thrombophilic factors should be carried out not only in young patients with spontaneous development of thrombosis, but also in elderly patients, even when an additional risk for the occurrence of thrombosis such as traumatization or immobilization is present. Therapeutic consequences are discussed.

Changes in platelet membrane glycoproteins before bone marrow transplantation and after engraftment--a pilot study.

Thrombotic complications are observed in patients undergoing bone marrow transplantation despite thrombocytopenia and impaired coagulation due to liver function disturbances. Endothelial cell damage which is involved in the pathogenesis of major transplant related complications like graft-versus-host disease, veno-occlusive disease, sepsis or microangiopathy may be a contributing factor. Little is known about platelet function in bone marrow transplant recipients. In order to study functional alterations in circulating platelets we investigated unstimulated and ADP-stimulated platelets of 10 bone marrow transplant recipients ex vivo by flow cytometry in a pilot study using a panel of monoclonal antibodies to characterize changes in membrane glycoproteins. Samples were collected before and during conditioning and at three timepoints after engraftment. 10 healthy volunteers served as controls. Platelets of bone marrow transplant recipients showed partly a significant, higher expression of surface bound fibrinogen, activated fibrinogen receptor, and glycoprotein Ib as compared to controls. P-selectin, a marker of platelet degranulation was significantly elevated after ADP-induced stimulation at all timepoints compared to controls. Only marginal differences were found for GP IIb/IIIa surface expression. The data point to an increased platelet activation state in bone marrow transplant recipients which might contribute to the thrombotic phenomena observed in these patients.

Endothelial cell markers in bone marrow transplant recipients with and without acute graft-versus-host disease.

To investigate endothelial cell alterations in BMT recipients developing acute graft-versus-host disease (aGVHD) we determined levels of the endothelial cell markers von Willebrand factor (VWF) and thrombomodulin (TM) in 57 patients undergoing BMT. Before conditioning VWF and TM levels did not differ significantly between transplant recipients who later developed no or mild (grade I) aGVHD (group A, allogeneic n = 22, autologous n = 7; VWF 136.0 +/- 44.1%; TM 29.5 +/- 18.0 ng/ml), and those with moderate or severe (grade II or III) aGVHD (group B, n = 28; VWF 142.2 +/- 37.6%; TM 35.2 +/- 20.1 ng/ml). A first significant rise of both VWF and TM level was noted after conditioning (day 0) both in group A (VWF 197.0 +/- 113.3%; P < 0.001; TM 39.3 +/- 23.3 ng/ml; P < 0.01) as well as in group B (VWF 201.7 +/- 53.3%; P < 0.0001; TM 43.5 +/- 23.5 ng/ml; P < 0.05). Subgroup analysis of autografted patients revealed no significant increase after conditioning in these patients. At the time of engraftment and onset of aGVHD (day 21), when VWF and TM levels within the groups were significantly elevated as compared with baseline (day -8) levels, group B patients (62.7 +/- 38.5 ng/ml) had significantly higher (P < 0.01) TM levels than patients of group A (37.4 +/- 19.6 ng/ml). This significant elevation also persisted at the end of the investigational period (day 28; group B: 56.0 +/- 37.6 ng/ml; group A: 38.2 +/- 23.7 ng/ml; P < 0.01). An elevation of endothelial cell markers is found in the course of BMT, particularly after conditioning and at the time of engraftment. This increase is pronounced in patients with aGVHD suggesting not only epithelial cell but also endothelial cell injury during aGVHD.

Plasminogen activator inhibitor-1 confirms the diagnosis of hepatic veno-occlusive disease in patients with hyperbilirubinemia after bone marrow transplantation.

Hepatic veno-occlusive disease (VOD) is a frequent and severe complication after bone marrow transplantation (BMT). We previously have described plasminogen activator inhibitor-1 (PAI-1) as a possible marker of VOD. To confirm the significance of this finding, we now determined PAI-1 levels in 31 of 186 consecutive patients undergoing BMT who developed hyperbilirubinemia greater than 3 mg/dL for various reasons. Diagnoses were made by clinical criteria and confirmed by biopsy in 23 of 31 patients. They included VOD (n = 7), acute graft-versus-host disease (GVHD) of the liver (n = 7), and other hepatic injury (n = 17). PAI-1 (mean +/- SD) was significantly (P < .001) elevated in patients with VOD (321.6 +/- 161.2 ng/mL) as compared with patients with GVHD (22.8 +/- 8.4 ng/mL) or other hepatic damage (32.8 +/- 30.8 ng/mL) at the timepoint of bilirubin increase. At the peak bilirubin concentration, the corresponding PAI-1 levels were 426.1 +/- 230.0 ng/mL in patients with VOD, 41.0 +/- 20.6 ng/ mL in patients with GVHD, and 44.6 +/- 32.9 ng/mL in patients with other hepatic injury (P < .001 VOD v GVHD/other hepatic injury). Our results underline the relevance of PAI-1 in the differential diagnosis of hyperbilirubinemia after BMT and its significance as a sensitive and specific marker of severe VOD.

Laboratory markers of veno-occlusive disease in the course of bone marrow and subsequent liver transplantation.

Plasminogen activator inhibitor 1 (PAI-1) and amino-propeptide of type III procollagen (PIIINP) have been described as markers of hepatic veno-occlusive disease (VOD) after bone marrow transplantation (BMT). We determined these parameters in two patients undergoing BMT and subsequent liver transplantation due to VOD. Previously normal PAI-1 levels (maximum 30.0 ng/ml in patient 1, 23.7 ng/ml in patient 2) were elevated for the first time in both patients at the time of clinically diagnosed VOD on days 40 and 20, respectively (patient 1: 317.5 ng/ml; patient 2: 317.2 ng/ml). Levels remained elevated until liver transplantation was performed on days 79 and 41, respectively. Baseline levels (day -8) of aminopropeptide of type III collagen (patient 1: 4.44 microg/l; patient 2: 8.1 microg/l) peaked at the time of BMT in both patients (155.0 microg/l and 108.3 microg/l). After an intermittent decrease at the time of discharge on day 32, a second elevation was observed in patient 1 when she was readmitted and presented with typical signs of VOD on day 40. In patient 2, PIIINP levels remained high until VOD was diagnosed (day 20) and liver transplantation was performed. After liver transplantation, PAI-1 levels normalized in both patients and PIIINP levels declined. Both patients died due to infectious complications and multiorgan failure on days 141 and 101, respectively. Whereas the early rise of PIIINP did not correlate with the clinical onset of VOD, the results emphasise the relevance of PAI-1 for diagnosing VOD.

Protein C, protein S and antithrombin III levels in the course of bone marrow and subsequent liver transplantation due to veno-occlusive disease.

Veno-occlusive disease (VOD) of the liver is one of the most frequent fatal complications after bone marrow transplantation (BMT). A decrease of natural anticoagulants, in particular protein C (PC), has been assumed to be involved in the pathogenesis of the disease. We determined PC and antithrombin III (AT III) levels in two patients undergoing BMT and subsequent liver transplantation due to VOD. Additionally, in one of the patients protein S (PS) levels were also measured. Normal baseline (day-8) PC levels (86 and 89%) were markedly reduced in both patients at the time of VOD manifestation on day 20 and 40, respectively (26 and 31%). PS levels lay within the normal range from day-8 (before myeloablative chemotherapy) until one week after clinical onset of VOD when substitution therapy with fresh frozen plasma (FFP) was initiated. AT III levels decreased moderately during the second and third posttransplant week, but were normal in the patient with a late clinical manifestation of VOD. In both patients PC and PS levels lay within the normal range after liver transplantation which was performed on day 41 and 79, respectively. AT III was substituted several times. Both patients died due to infectious complications on day 141 and 101, respectively. The data confirm previous reports that a decrease of PC is observed in BMT recipients and can be associated with hepatic vein occlusion. Whereas the relevance of AT III is uncertain, PS does not seem to be involved in the pathogenesis of VOD. Liver transplantation lead to normalization of PC levels, but its significance remains to be discussed in terms of ethical justifiability, medical feasibility and costs.

Hemostatic parameters in sepsis patients treated with anti-TNF alpha-monoclonal antibodies.

Tumor necrosis factor-alpha (TNF alpha) is a central mediator in the pathogenesis of sepsis. It also interferes with the hemostatic system and exerts and a net procoagulant effect. Since TNF alpha may contribute to thrombotic complications in sepsis patients, we determined markers of thrombin activation, parameters of the fibrinolytic system (D-dimer, tissue plasminogen activator antigen (tPA) urinary type plasminogen activator antigen (uPA), plasminogen activator inhibitor antigen (PAI-1) and von Willebrand factor antigen (vWF) in 30 patients with sepsis or septic shock. All patients were treated with standard therapy, but 14 patients were treated additionally with an anti-TNF alpha monoclonal antibody (MAK 195F); 16 patients served as historical controls. No significant effect of the antibody on the parameters of the hemostatic system could be determined. Our data speak against a modulation of coagulation or the fibrinolytic system by the monoclonal anti-TNF alpha antibody MAK 195F in this cohort of sepsis patients.

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.

[Hypercoagulability in patients with veno-occlusive disease after bone marrow transplantation]. / Hyperkoagulabilität bei Patienten mit venookklusiver Erkrankung nach Knochenmarktransplantation.

BACKGROUND: Veno-occlusive disease (VOD) leads to obliteration of small intrahepatic venules and is one of three most important complications with fatal outcome after bone marrow transplantation (BMT). The etiology of VOD is not completely understood. Endothelial cell injury induced by the conditioning myeloablative radiochemotherapy with subsequent activation of the coagulation cascade seems to be a crucial step in the pathogenesis of the disease. PATIENTS AND METHODS: We investigated tissue plasminogen activator (tPA), its main inhibitor (PAI-1) and the natural anticoagulants protein C and S by enzymimmunoassay prospectively in 32 bone marrow transplant recipients. RESULTS: VOD developed in four patients. They presented with extremely elevated levels of PAI-1 after BMT whereas tPA levels remained low. Additionally a transient decrease of protein S was found one week after BMT which was more pronounced in VOD patients. No protein C deficiency was observed. CONCLUSION: Our data suggest that hypofibrinolysis due to an excess of PAI-1 may be involved in the pathogenesis of VOD. The determination of PAI-1 may be useful to recognize the development of VOD and facilitate the decision for thrombolytic therapy with rtPA. A decrease of protein S may play a role as a cofactor in the early phase after BMT.