Biomarker profiling of steroid-resistant acute GVHD in patients after infusion of mesenchymal stromal cells.

We performed a prospective phase II study to evaluate clinical safety and outcome in 48 patients with steroid-refractory grade II-IV acute graft-versus-host disease (aGVHD) treated with mesenchymal stromal cells (MSCs). Clinical outcomes were correlated to comprehensive analyses of soluble and cellular biomarkers. Complete resolution (CR) of aGVHD at day 28 (CR-28) occurred in 12 (25%) patients, CR lasting >1 month (CR-B) occurred in 24 (50%) patients. One-year overall survival was significantly improved in CR-28 (75 versus 33%, P=0.020) and CR-B (79 versus 8%, P<0.001) versus non-CR patients. A six soluble biomarker-panel was predictive for mortality (HR 2.924; CI 1.485-5.758) when measured before MSC-administration. Suppression of tumorigenicity 2 (ST2) was only predictive for mortality 2 weeks after but not before MSC-administration (HR 2.389; CI 1.144-4.989). In addition, an increase in immature myeloid dendritic cells associated with decreased mortality (HR 0.554, CI 0.389-0.790). Patients had persisting T-cell responses against defined virus- and leukemia-associated antigens. In conclusion, our data emphasize the need to carefully assess biomarkers in cohorts with homogeneous GVHD treatments. Biomarkers might become an additional valuable component of composite end points for the rapid and efficient testing of novel compounds to decrease lifecycle of clinical testing and improve the success rate of phase II/III trials.

Oral complications in hematopoietic stem cell recipients: the role of inflammation.

Hematopoietic stem cell transplantation (HSCT) is widely used as a potentially curative treatment for patients with various hematological malignancies, bone marrow failure syndromes, and congenital immune deficiencies. The prevalence of oral complications in both autologous and allogeneic HSCT recipients remains high, despite advances in transplant medicine and in supportive care. Frequently encountered oral complications include mucositis, infections, oral dryness, taste changes, and graft versus host disease in allogeneic HSCT. Oral complications are associated with substantial morbidity and in some cases with increased mortality and may significantly affect quality of life, even many years after HSCT. Inflammatory processes are key in the pathobiology of most oral complications in HSCT recipients. This review article will discuss frequently encountered oral complications associated with HSCT focusing on the inflammatory pathways and inflammatory mediators involved in their pathogenesis.

Bidirectional modulation of endogenous EpCAM expression to unravel its function in ovarian cancer.

BACKGROUND: The epithelial cell adhesion molecule (EpCAM) is overexpressed on most carcinomas. Dependent on the tumour type, its overexpression is either associated with improved or worse patient survival. For ovarian cancer, however, the role of EpCAM remains unclear. METHODS: Cell survival of ovarian cancer cell lines was studied after induction or repression of endogenous EpCAM expression using siRNA/cDNA or artificial transcription factors (ATF) consisting of engineered zinc-fingers fused to either a transcriptional activator or repressor domain. RESULTS: Two ATFs were selected as the most potent down- and upregulator, showing at least a two-fold alteration of EpCAM protein expression compared with control. Downregulation of EpCAM expression resulted in growth inhibition in breast cancer, but showed no effect on cell growth in ovarian cancer. Induction or further upregulation of EpCAM expression decreased ovarian cancer cell survival. CONCLUSION: The bidirectional ATF-based approach is uniquely suited to study cell-type-specific biological effects of EpCAM expression. Using this approach, the oncogenic function of EpCAM in breast cancer was confirmed. Despite its value as a diagnostic marker and for immunotherapy, EpCAM does not seem to represent a therapeutic target for gene expression silencing in ovarian cancer.

BK virus infection in transplant recipients: clinical manifestations, treatment options and the immune response.

Polyomavirus BK (BKV) is ubiquitously present amongst the general population establishing a latent, seemingly asymptomatic infection in immunocompetent individuals. In transplant recipients, however, BKV reactivation is common and can lead to distinctive pathological entities in different patient groups: in renal transplant (RT) recipients, it is associated with nephropathy (BKVN) and ureteral stenosis, and in haematopoietic stem cell transplant (HSCT) recipients with haemorrhagic cystitis (HC). Furthermore, BKV employs several potentially oncogenic mechanisms to promote its replication in cells and has been inconsistently linked to the development of malignancies. BKVN is currently a major cause of allograft failure in RT recipients. HC causes prolonged hospital stay and increased mortality in HSCT recipients. Despite its discovery more than 40 years ago, few advances have been made with regard to therapeutic strategies. Current therapies aim to restore the impaired immune response, e.g. by lowering immunosuppressive agents in RT recipients. However, this is a double-edged sword since it also increases the chance of rejection. Therefore, more specific and effective treatment strategies are urgently needed. Here, we will review the current knowledge on the structure and lifecycle of BKV, characteristics of the BKV-specific immune response, its clinical manifestations and the strengths and limitations of available treatments Polyomavirus BK (BKV) is ubiquitously present amongst the general population establishing a latent, seemingly asymptomatic infection in immunocompetent individuals. In transplant recipients, however, BKV reactivation is common and can lead to distinctive pathological entities in different patient groups: in renal transplant (RT) recipients, it is associated with nephropathy (BKVN) and ureteral stenosis, and in haematopoietic stem cell transplant (HSCT) recipients with haemorrhagic cystitis (HC). Furthermore, BKV employs several potentially oncogenic mechanisms to promote its replication in cells and has been inconsistently linked to the development of malignancies. BKVN is currently a major cause of allograft failure in RT recipients. HC causes prolonged hospital stay and increased mortality in HSCT recipients. Despite its discovery more than 40 years ago, few advances have been made with regard to therapeutic strategies. Current therapies aim to restore the impaired immune response, e.g. by lowering immunosuppressive agents in RT recipients. However, this is a double-edged sword since it also increases the chance of rejection. Therefore, more specific and effective treatment strategies are urgently needed. Here, we will review the current knowledge on the structure and lifecycle of BKV, characteristics of the BKV-specific immune response, its clinical manifestations and the strengths and limitations of available treatments methods.

Kytococcus schroeteri pneumonia in two patients with a hematological malignancy.

Neutropenic patients are susceptible to infections with usually harmless microorganisms. We report two cases of severe pneumonia in hematological patients due to Kytococcus schroeteri, a saprophyte of the human skin. When blood cultures or respiratory specimens yield micrococcus-like colonies, Kytococcus species, which are often resistant to penicillin, should be considered and the antimicrobial therapy should be adjusted accordingly.

Cardiac arrest in pregnancy: increasing use of perimortem caesarean section due to emergency skills training?

OBJECTIVE: Management of cardiac arrest in pregnancy is recommended to include perimortem caesarean section (PMCS) in the Managing Obstetric Emergencies and Trauma (MOET) course. In this study, we aimed to assess maternal and neonatal outcome of all cases of PMCS in the Netherlands performed in the last 15 years, and to test the hypothesis that PMCS was used more often since the introduction of the MOET-course in 2004. DESIGN: Retrospective cohort study. SETTING: Nationwide assessment of all cases of PMCS inside or outside hospitals. POPULATION: All known cases of PMCS in the Netherlands from 1993 to 2008. METHODS: Data collection through contacting all Dutch obstetricians and all MOET and Advanced Trauma Life Support instructors. All cases of cardiac arrest during pregnancy were collected by cross-checking with data from the Dutch Maternal Mortality Committee and a nationwide severe maternal morbidity study. MAIN OUTCOME MEASURES: Incidence and case fatality rate of PMCS. Incidence of PMCS before and after introduction of the MOET course. Maternal and neonatal outcome and the process of the PMCS were analysed. RESULTS: During the study period, 55 women had a cardiac arrest, 12 of whom underwent a PMCS. Before the introduction of the MOET course, four PMCSs were performed (0.36/year), compared with eight cases after its introduction (1.6/year, P = 0.01). No PMCS was performed within the recommended 5 minutes after starting resuscitation. Eight of the twelve women (67%) regained cardiac output after PMCS, with two maternal and five neonatal survivors. Maternal case fatality rate was 83%. Neonatal case fatality rate was 58%. CONCLUSIONS: Since the introduction of the MOET course, the use of PMCS has increased. Outcome, however, was still poor. An important factor to improve outcome is more timely application of this potentially life-saving procedure.

Experience with alemtuzumab in treatment of chronic lymphocytic leukaemia in the Netherlands.

BACKGROUND: Alemtuzumab (MabCampath) is a monoclonal antibody against CD52, indicated as third-line treatment of chronic lymphocytic leukaemia (CLL). As most important side effect opportunistic infections are mentioned. It is, however, unknown whether these complications often lead to problems in general patient care in the Netherlands. METHODS: To gain insight into the use and complications of alemtuzumab therapy, the alemtuzumab-treated CLL patients in 15 hospitals in the Netherlands were evaluated by means of a questionnaire. RESULTS: In the period from 31 October 2001 until 17 November 2005, 27 patients with CLL or prolymphocytic leukaemia (PLL), RAI stage I to IV, Binet stage A to C, received 32 treatments with alemtuzumab. The time from diagnosis until start of alemtuzumab treatment was 6 +/- 4.5 years (mean +/- SD ). The treatment lasted 11 +/- 7 weeks. Of the treatments, 41% could be administered for the full 12 weeks. The most frequent adverse events were fever (72%), shivering (47%), fatigue (22%) and dyspnoea (16%). Haematological side effects consisted of leucopenia (75%), thrombocytopenia (44%), and anaemia (13%). Infectious complications occurred in 12 of 32 (38%) treatments: pneumonia (25%; of which one Pneumocystis carini pneumonia and four Aspergillus infections), sepsis (9%; of which one Listeria), herpes zoster (9%), herpes simplex (6%), CMV reactivation (6%), meningitis (3%) and Guillain Barre (3%). The overall response was 53%, with complete remission in 13%, partial remission in 41%, stable disease in 25% and progressive disease in 13%, and lasted for 8.3 +/- 7.3 months. CONCLUSION: Treatment with alemtuzumab is often terminated prematurely, leading to a suboptimal treatment effect. Fear of severe uncontrollable opportunistic infections seems unjustified.

Chimerism analysis within 6 months of allogeneic stem cell transplantation predicts relapse in acute myeloid leukemia.

The role of chimerism analysis as a prognostic indicator of relapse after hematopoietic stem cell transplantation (SCT) is controversial. We monitored chimerism status by short tandem repeat-based polymerase chain reaction (PCR) in T- and non-T-cell subsets and retrospectively evaluated clinical outcome in 96 patients with acute myeloid leukemia after myeloablative (MA) or reduced-intensity conditioning SCT. Fifty-six percent of 80 patients in the MA group demonstrated complete donor chimerism (CC) at all time points, whereas 6% had decreasing mixed chimerism (MC), 8% stable MC, 25% increasing MC and 3% increasing and decreasing MC. In 16 RIC patients, these percentages were 12, 50, 6, 6 and 19, respectively, together with 6% nonengraftment. Forty-three out of 96 patients experienced relapse. The last chimerism evaluation before relapse revealed increasing MC in only eight patients. In samples taken between 1 and 6 months post SCT, CC/decreasing MC was significantly related with a lower risk of relapse (31 versus 83%, P<0.000) and mortality (38 versus 83%, P<0.000) than with MC/increasing MC. However, the development of relapse was very rapid. Only very frequent monitoring of chimerism status by highly sensitive methods might identify impending relapse and allow early immunological intervention.

Pulmonary complications after T-cell-depleted allogeneic stem cell transplantation: low incidence and strong association with acute graft-versus-host disease.

Lung injury limits the success of allogeneic stem cell transplantation (SCT). The overall incidence varies from 30 to 50% and non-infectious causes occur in one-third to one-half of these. We reviewed pulmonary complications in 369 consecutive patients who received a partially T-cell-depleted myeloablative allogeneic hematopoietic SCT at our institution between 1993 and 2003. All patients were treated uniformly with cyclophosphamide followed by total body irradiation. Control subjects were matched on sex, underlying diagnosis, age, type of transplantation and cytomegalovirus (CMV)-serostatus. Sixty-one patients (16.5%) developed pulmonary complications. Twenty-one patients (5.7%) developed infectious pneumonia. Forty patients developed non-infectious complications which were further subclassified as bronchiolitis obliterans (3.5%), bronchiolitis obliterans-organizing pneumonia (0.5%), diffuse alveolar hemorrhage (0.8%), idiopathic pneumonia syndrome (5.5%) or mixed etiology (0.5%). Acute graft-versus-host disease (GVHD) > or =grade II was significantly more common in pulmonary patients than in the controls (36/61 versus 22/61 patients, P=0.02). There was no significant difference in the incidence of chronic GVHD (P=0.09). CMV reactivation was significantly more frequent in patients with lung injury (P=0.02). Median survival was 41 weeks for the pulmonary patients and 350 weeks for the controls (P=0.001). Altogether, the incidence of pulmonary complications is low after T-cell-depleted SCT and is associated with acute GVHD and CMV reactivation.

Accelerated cisplatin and high-dose epirubicin with G-CSF support in patients with relapsed non-small-cell lung cancer: feasibility and efficacy.

The purpose of this study is to determine whether it is feasible to administer high-dose epirubicin (135 mg m(-2)) combined with a fixed dose of cisplatin every 2 weeks with G-CSF support in patients with metastatic non-small-cell lung cancer (NSCLC). Subsequently, the efficacy of the recommended dose of this regimen was tested in a phase II study in patients with relapsed NSCLC. In the initial feasibility study at least 6 patients were entered at each of the 4 dose levels tested. A fixed dose of cisplatin 60 mg m(-2) was given. Epirubicin was administered at 120 mg m(-2) on dose level 1, 135 mg m(-2) on dose level 2 and 3 and 135 mg m(-2) on dose level 4. Patients treated at dose level 3 and 4 received G-CSF support on days 3-12. Cycles were repeated every 3 weeks on the first 3 dose levels and every 2 weeks on the fourth dose level. A total of 27 patients were then treated on dose level 4, which appeared to be feasible in the initial study. In the initial study, a total of 86 courses were administered. Haematological toxicity was the principal side effect. None of the patients encountered dose-limiting toxicity in the first course, which confirmed that epirubicin 135 mg m(-2) could be combined with cisplatin 60 mg m(-2) and accelerated by G-CSF support to a 14-day-schedule. In the subsequent phase II study with this schedule, 89 courses were administered. The relative dose intensity of cisplatin and epirubicin was 0.90 and 0.91, respectively. Myelosuppression was frequent with 70% and 63% of patients experiencing WHO grade III or IV leukocytopenia and thrombocytopenia, respectively. 6 cases of febrile neutropenia were observed, with 2 treatment-related deaths. Non-haematological toxicity consisted mainly of nausea and vomiting, which was grade III in 22% of patients. Renal toxicity grade I and II occurred in 37% and 4% of patients, respectively. 55% of these patients had received prior cisplatin-containing chemotherapy. On an intention-to-treat basis 9 partial responses were recorded in 27 patients (33%; 95% confidence interval, 15%-51%). Accelerated cisplatin and high-dose epirubicin with G-CSF support is a feasible and promising regimen in relapsed NSCLC. Myelosuppression limits the use of this regimen in the second-line setting to a selected group of patients with a good performance status. Since the activity of this regimen is encouraging, it is probably best studied in untreated patients.

Combination of gemcitabine and cisplatin for advanced non-small cell lung cancer: a phase II study with emphasis on scheduling.

BACKGROUND: Many regimens of gemcitabine-cisplatin chemotherapy have proven activity in patients with advanced non-small cell lung cancer (NSCLC). However, the optimal dose and schedule still have to be established. PATIENTS AND METHODS: We conducted a phase II study with administration of cisplatin 50 mg/m(2) on days 1 and 8 and gemcitabine 800 mg/m(2) on days 2, 9 and 15. This schedule was selected to optimise the synergism between the two drugs and reduce toxicity due to high dose cisplatin. RESULTS: Thirty-six chemo-naive patients with stage IIIA, IIIB or IV NSCLC entered the study (26 men, 10 women; median age 58 years, range 29-74). Twenty patients achieved a partial response: 7 out of 10 stage IIIA patients, 7 out of 13 stage IIIB patients and 6 out of 13 stage IV patients. On intent-to-treat basis, the overall response rate (RR) was 58% (95% confidence interval, 42-74%). Ninety percent of stage IIIA patients and 46% of stage IIIB patients received adjuvant surgery or radiotherapy. Overall median duration of response was 28 weeks (range 6-147 weeks). For stage IIIA, IIIB and IV patients, these numbers were 91, 13 and 23 weeks, respectively. One-year survival was 49% with 90%, 23% and 42% for stage IIIA, IIIB and IV patients, respectively. The main toxicity was myelosuppression. WHO grades 3 and 4 leukopenia occurred in 67% of patients, whereas 61% experienced grade 3 or 4 thrombocytopenia. Although hematological toxicity was clinically tolerable, it frequently led to omission of gemcitabine administration on day 15. The incidence of non-hematological toxicity was very low. CONCLUSION: This regimen of cisplatin on days 1 and 8 and gemcitabine on days 2, 9 and 15 induced a high RR in patients with advanced NCSLC. Frequent omission of gemcitabine day 15 is a limitation of this schedule. This should be an important factor in a practical approach to decide on the most optimal schedule of the cisplatin plus gemcitabine combination.

A phase I study of sequential intravenous topotecan and etoposide in lung cancer patients.

PURPOSE: The topoisomerase I inhibitor topotecan (T) and the topoisomerase II inhibitor etoposide (E) are active drugs in lung cancer. The complementary functions of their targets may suggest benefit from the combined use of these agents but drug scheduling has been shown to play a critical role in preclinical models. To establish the optimal schedule and assess the impact of sequential administration of the combination of T and E, we conducted a dose finding study of sequential intravenous T and E in a four-weekly-schedule in relapsed lung cancer patients. PATIENTS AND METHODS: The importance of drug sequence was assessed in consecutive patients throughout all dose levels; patients received in the first course either T followed by E (the TE group: T on days 1-3 and E on days 4-6) or E before T (the ET group: F on days 1-3 and Ton days 4-6). The sequence of Tand E was alternated in the successive courses. In this crossover design, each patient served as his own control for analysis of hematological toxicity in which TE sequence was compared to that of the ET sequence. Moreover, hematological toxicity after the first course was compared between the TE and the ET groups. The starting dose was T/E 0.75/75 mg/m2 at dose level 1and dose escalation was planned to T/E 1.00/75 mg/nm2 at dose level 2, T/E 1.00/100 mg/m2 at dose level 3, T/E 1.25/100 mg/m2 at dose level 4 and T/E 1.50/100 mg/m2 at dose level 5. Nineteen patients (small-cell lung cancer 7, non-small-cell lung cancer 11, mesothelioma 1 patient) were included. RESULTS: The principal toxicity was myelosuppression, primarily neutropenia and thrombocytopenia. At dose level 3 several grade 4 toxicities were observed. DLT (febrile neutropenia) occurred in two patients, one in the TE and one in the ET group and precluded further dose escalation. There was no significant difference in WBC and platelet nadirs during the first course between the TE and the ET group. The influence of the sequence of administration of topotecan and etoposide was calculated by comparing the nadir values of cycles I and II for each patient. For none of the dose levels, a significant sequence-dependent effect could be detected. The MTD was reached at the doses of 100 mg/m2 topotecan and 75 mg/m2 etoposide. No objective responses were seen. CONCLUSION: Although the combined use of topoisomerase I and II inhibitors is attractive on theoretical grounds, excessive myelosuppression prevents substantial dose escalation.

Endobronchial lipoma: a series of three cases and the role of electrocautery.

Lipomas are rare endobronchial tumors that may cause severe parenchymal damage due to bronchus obstruction and subsequent pneumonia. Therefore, accurate diagnosis and radical treatment are essential. We describe three cases of endobronchial lipoma. One patient presented with hemoptysis, two patients were initially diagnosed as COPD. They were all treated by electrocautery which achieved complete removal. We recommend electrocautery as an easy and cost-effective alternative for removal of intraluminal tumors including lipoma.

Second-line chemotherapy in relapsing or refractory non-small-cell lung cancer: a review.

PURPOSE: Since the increased use of first-line chemotherapy for non-small-cell lung cancer (NSCLC), second-line chemotherapy may nowadays be considered for a growing group of patients. Guidelines for second-line treatment have to be developed yet. METHODS: We reviewed the published literature on second-line chemotherapy for NSCLC with emphasis on the role of factors such as pretreatment, response to first-line treatment, and length of disease-free-interval. RESULTS: Thirty-four single-agent-studies and 24 multidrug-studies on second-line treatment were identified. Docetaxel has been studied most extensively and is the only agent that has been studied in randomized phase III trials. Different definitions of sensitivity applied by different authors and conflicting results have been reported about the influence of response to prior chemotherapy. CONCLUSION: Since most patients are treated with a platinum-based regimen in the first line, platinum resistance usually is a major consideration for the use of second-line agents. We argue, however, that a more general definition of drug resistance is more appropriate than resistance to platinum only. Criteria to select NSCLC patients for second-line treatment have not been defined yet. This is also important in light of the upcoming necessity to test new drugs in pretreated instead of treated patients. Guidelines for second-line treatment of NSCLC based on clinical information on drug sensitivity to first-line therapy need to be developed.

Second-line chemotherapy and its evaluation in small cell lung cancer.

The literature on second-line chemotherapy for small cell lung cancer between 1989-1999 is reviewed. The reports consisted mainly of phase II studies and included a total of 1749 patients. The information was frequently incomplete with respect to duration of response on first-line chemotherapy and the length of treatment free interval. The overall second-line response rate was 20%. Obviously, new chemotherapy regimens are needed for relapsed small cell lung cancer. We propose a methodology for future trials based on the distinction between sensitive and refractory patients. The latter group of patients who progress on or within a short time of induction of treatment are candidates for single arm phase II trials with agents with unknown or new mechanisms of action or new combination regimens. The sole endpoint of this type of phase II studies is response rate. For sensitive patients we propose re-induction chemotherapy as the standard against which investigational agents or combination regimens should be tested. Major end-points include response rate, toxicity and quality of life. Regimens with demonstrated therapeutic activity in this setting could be tested as first-line chemotherapy in phase II trials.

Relationship between soluble transferrin receptors in serum and membrane-bound transferrin receptors.

The expression of transferrin receptors on the cell membrane of erythroblasts was analysed with flow cytometry in patients with different forms of anaemia. At the same time the concentration of soluble transferrin receptors (sTfRs) was analysed in serum. It was shown that only in iron deficiency a high concentration of sTfRs in serum could be explained with an increased expression of transferrin receptors on the erythroblastic membrane. In anaemia of chronic disease and myelodysplasia a discrepancy between a low expression on the cell membrane and normal or elevated serum values was seen. From this study we conclude that the concentration of sTfRs in serum does not only depend on the expression of transferrin receptors on the erythroblasts but also on the erythroid activity.

The expression of transferrin receptors on erythroblasts in anaemia of chronic disease, myelodysplastic syndromes and iron deficiency.

The presence of transferrin receptors on erythroblasts in patients with iron deficiency, anaemia of chronic disease (ACD) and myelodysplastic syndrome (MDS) was studied by two-colour analysis on a flow cytometer. CD 71 was used to quantify the number of transferrin receptors and GLY-A to identify erythroblasts. In cases of iron deficiency, the number of transferrin receptors was increased on part of the erythroblasts thus facilitating iron uptake by the cells. In patients with ACD or MDS, a decrease of the number of transferrin receptors on erythroblasts was found. This leads to the conclusion that the ineffective response to iron therapy in cases of ACD and MSD can be explained by a decline of transferrin receptors on the red cells.

Reversal of multidrug resistance by SDZ PSC 833, combined with VAD (vincristine, doxorubicin, dexamethasone) in refractory multiple myeloma. A phase I study.

SDZ PSC 833, a non-immunosuppressive cyclosporin analogue reverses multidrug resistance (MDR) in vitro by inhibiting P-glycoprotein (P-gp) mediated drug efflux. We performed a dose escalation study of SDZ PSC 833 combined with VAD chemotherapy in refractory multiple myeloma (MM). Twenty-two MM patients who were refractory to doxorubicin/vincristine/dexamethasone (VADr, n=11) or had failed multiple regimens (n=6) or were melphalan-refractory (MELr, n=5), were treated with one to three cycles of VAD combined with oral SDZ PSC 833, which was administered at escalating dosages starting at 5 mg/kg/day to 15 mg/kg/day for 7 days. The median trough and peak blood levels of SDZ PSC 833 ranged from 461/1134 ng/ml at 5 mg/kg/day to 821/2663 ng/ml at 15 mg/kg, respectively. With addition of SDZ PSC 833 (5 mg/kg) the mean plasma AUC 0-->96 h of doxorubicin as compared with control patients treated with VAD increased from 779 to 1510 ng/ml/h (P=0.0071), while the doxorubicin clearance was reduced from 47.6 to 27.8 l/h/m2 (P=0.0002). The clearance of doxorubicinol was reduced accordingly. Because of the increased plasma AUC, the dose of doxorubicin and vincristine had to be reduced in 13 patients to 50% (n=1) or 75% (n=12). A further dose-escalation of SDZ PSC 833 did not lead to a proportional increase of doxorubicin AUC. Toxicity WHO CTC grade 2 or 3 included hypoplasia (18/22), constipation (10/22), hyponatremia (3/22) and infections (6/22). A partial response or stable disease was achieved in eight and six patients, respectively. In 17 evaluable patients the mean percentage of pretreatment bone marrow plasma cells which expressed P-glycoprotein was 40%. The pretreatment in vitro rhodamin retention in CD38++ myeloma cells was reversible by 2 microM SDZ PSC 833 with 15-98% in 7/9 tested patients. In 4/5 responding patients analyzed before and after treatment with VAD + SDZ PSC 833, a reduction of P-gp + plasma cells was observed. It is concluded, that the blood concentrations of SDZ PSC 833 attained in MM patients increase with dose after oral administration. It can be safely combined with VAD chemotherapy. SDZ PSC 833 diminishes the clearance of doxorubicin, leading to an increase of the plasma AUC of doxorubicin. In addition, it is an effective inhibitor of P-gp mediated efflux of doxorubicin in myeloma tumor cells in vitro. Therefore, a proportional dose-reduction of doxorubicin and vincristine is warranted. Phase II/III studies in refractory MM are in progress to evaluate the therapeutic efficacy of SDZ PSC 833 with VAD.

Analytical and clinical implications of soluble transferrin receptors in serum.

In this study the analytical performances of two recently introduced assays for soluble transferrin receptors in serum were tested. The Ramco transferrin assay was compared with the Eurogenetics assay. In a small clinical study serum samples from patients with anaemia of chronic disease, iron deficiency and myelodysplastic syndrome were analysed, as well as sera from healthy volunteers. The analytical performances of the Ramco assay were found to be acceptable. In the Eurogenetics test however, inter-assay imprecision and the end of run drift were unacceptably high. We were able to confirm that in patients with uncomplicated iron deficiency the concentration of soluble transferrin receptors is higher than in healthy volunteers. In cases of anaemia of chronic and inflammatory disease, the levels of soluble transferrin receptors in serum are slightly, but not significantly, higher than in normal subjects. Measurement of soluble transferrin receptors in serum provides a good differentiation between anaemia of chronic disease and iron deficiency.