Remission induction versus immediate allogeneic haematopoietic stem cell transplantation for patients with relapsed or poor responsive acute myeloid leukaemia (ASAP): a randomised, open-label, phase 3, non-inferiority trial.

BACKGROUND: Whether high-dose cytarabine-based salvage chemotherapy, administered to induce complete remission in patients with poor responsive or relapsed acute myeloid leukaemia scheduled for allogeneic haematopoietic stem-cell transplantation (HSCT) after intensive conditioning confers a survival advantage, is unclear. METHODS: To test salvage chemotherapy before allogeneic HSCT, patients aged between 18 and 75 years with non-favourable-risk acute myeloid leukaemia not in complete remission after first induction or untreated first relapse were randomly assigned 1:1 to remission induction with high-dose cytarabine (3 g/m2 intravenously, 1 g/m2 intravenously for patients >60 years or with a substantial comorbidity) twice daily on days 1-3 plus mitoxantrone (10 mg/m2 intravenously) on days 3-5 or immediate allogeneic HSCT for the disease control group. Block randomisation with variable block lengths was used and patients were stratified by age, acute myeloid leukaemia risk, and disease status. The study was open label. The primary endpoint was treatment success, defined as complete remission on day 56 after allogeneic HSCT, with the aim to show non-inferiority for disease control compared with remission induction with a non-inferiority-margin of 5% and one-sided type 1 error of 2·5%. The primary endpoint was analysed in both the intention-to-treat (ITT) population and in the per-protocol population. The trial is completed and was registered at ClinicalTrials.gov, NCT02461537. FINDINGS: 281 patients were enrolled between Sept 17, 2015, and Jan 12, 2022. Of 140 patients randomly assigned to disease control, 135 (96%) proceeded to allogeneic HSCT, 97 (69%) after watchful waiting only. Of 141 patients randomly assigned to remission induction, 134 (95%) received salvage chemotherapy and 128 (91%) patients subsequently proceeded to allogeneic HSCT. In the ITT population, treatment success was observed in 116 (83%) of 140 patients in the disease control group versus 112 (79%) of 141 patients with remission induction (test for non-inferiority, p=0·036). Among per-protocol treated patients, treatment success was observed in 116 (84%) of 138 patients with disease control versus 109 (81%) of 134 patients in the remission induction group (test for non-inferiority, p=0·047). The difference in treatment success between disease control and remission induction was estimated as 3·4% (95% CI -5·8 to 12·6) for the ITT population and 2·7% (-6·3 to 11·8) for the per-protocol population. Fewer patients with disease control compared with remission induction had non-haematological adverse events grade 3 or worse (30 [21%] of 140 patients vs 86 [61%] of 141 patients, χ2 test p<0·0001). Between randomisation and the start of conditioning, with disease control two patients died from progressive acute myeloid leukaemia and zero from treatment-related complications, and with remission induction two patients died from progressive acute myeloid leukaemia and two from treatment-related complications. Between randomisation and allogeneic HSCT, patients with disease control spent a median of 27 days less in hospital than those with remission induction, ie, the median time in hospital was 15 days (range 7-64) versus 42 days (27-121, U test p<0·0001), respectively. INTERPRETATION: Non-inferiority of disease control could not be shown at the 2·5% significance level. The rate of treatment success was also not statistically better for patients with remission induction. Watchful waiting and immediate transplantation could be an alternative for fit patients with poor response or relapsed acute myeloid leukaemia who have a stem cell donor available. More randomised controlled intention-to-transplant trials are needed to define the optimal treatment before transplantation for patients with active acute myeloid leukaemia. FUNDING: DKMS and the Gert and Susanna Mayer Stiftung Foundation.

Prospective analysis of the attendance behaviour of the participants of a facilitated support group for patients after allogeneic hematopoietic cell transplantation.

PURPOSE: Support groups might help survivors of allogeneic hematopoietic cell transplantations (HCT) to cope with medical, psychological, and social challenges. The aim of this project was (1) to establish a facilitated post-HCT support group and (2) to assess the participation behaviour. METHODS: From 11/2013 until 7/2017, all adult patients who had received a HCT at our centre were invited to participate in a professionally facilitated support group. The format of the group was unstructured without any rules regarding regular attendance. The attendance was prospectively minuted by the facilitator. Reasons for non-attendance were assessed by a survey. RESULTS: During the observation period, 53 group meetings were scheduled. Nine meetings were cancelled because of low attendance. Altogether 23 different patients (F: n=10; M: n=13) and 10 spouses (F: n=9; M: n=1) participated. Median participation was 5 [range 2-11]. With respect to all HCT patients who had the theoretical opportunity to attend, the mean participation rate was 7%. Thirteen patients and four spouses attended more than one meeting. The median count of participations among those participants was 8 [2-32]. The median interval from the first until the last participation was 16 months. The main reason reported for non-participation was the effort to get to the venue of the support group. CONCLUSIONS: To our knowledge, this is the first analysis on the attendance behaviour of the participants of a support group for HCT survivors. The results provide guidance for the organization of future support groups and indicate what participation rates can be expected and how they might be increased.

Characteristics and outcome of patients with acute myeloid leukemia and trisomy 4.

We retrospectively studied 125 patients with acute myeloid leukemia and trisomy 4 (median age at diagnosis, 58 years; range, 16-77 years) treated between 2000 and 2019 within a multicenter study. Trisomy 4 was the sole abnormality in 28 (22%) patients and additional abnormalities were present in 97 (78%) patients. Twenty-two (22%) and 15 (15%) of 101 tested patients harbored NPM1 and FLT3-ITD mutations. Two (3%) of 72 tested patients had double CEBPA mutations. Data on response to intensive anthracycline-based induction therapy were available for 119 patients. Complete remission was achieved in 67% (n=80) and the early death rate was 5% (n=6). Notably, patients with trisomy 4 as sole abnormality had a complete remission rate of 89%. Allogeneic hematopoietic cell transplantation was performed in 40 (34%) patients, of whom 19 were transplanted in first complete remission. The median follow-up of the intensively treated cohort was 5.76 years (95% confidence interval [95% CI]: 2.99-7.61 years). The 5-year overall survival and relapse-free survival rates were 30% (95% CI: 22-41%) and 27% (95% CI: 18-41%), respectively. An Andersen-Gill regression model on overall survival revealed that favorable-risk according to the European LeukemiaNet classification (hazard ratio [HR]=0.34; P=0.006) and trisomy 4 as sole abnormality (HR=0.41; P=0.01) were favorable factors, whereas age with a difference of 10 years (HR=1.15; P=0.11), female gender (HR=0.74; P=0.20) and allogeneic hematopoietic cell transplantation (HR=0.64; P=0.14) did not have an significant impact. In our cohort, patients with trisomy 4 as their sole abnormality had a high complete remission rate and favorable clinical outcome. Allogeneic hematopoietic cell transplantation did not seem to improve overall survival.

Definition of factors associated with negative antibody response after COVID-19 vaccination in patients with hematological diseases.

COVID-19 in patients with hematological diseases is associated with a high mortality. Moreover, preventive vaccination demonstrated reduced efficacy and the knowledge on influencing factors is limited. In this single-center study, antibody levels of the SARS-CoV-2 spike protein were measured ≥ 2 weeks after 2nd COVID-19 vaccination with a concentration ≥ 0.8 U/mL considered positive. Between July and October 2021, in a total of 373 patients (median age 64 years, 44% women) with myeloid neoplasms (n = 214, 57%), lymphoid neoplasms (n = 124, n = 33%), and other diseases (n = 35, 10%), vaccination was performed with BNT162b2 (BioNTech), mRNA-1273 (Moderna), ChADOx1 (AstraZeneca), or a combination. A total of 229 patients (61%) were on active therapy within 3 months prior vaccination and 144 patients (39%) were previously treated or treatment naïve. Vaccination-related antibody response was negative in 56/373 patients (15%): in 39/124 patients with lymphoid neoplasms, 13/214 with myeloid neoplasms, and 4/35 with other diseases. Active treatment per se was not correlated with negative response. However, rituximab and BTK inhibitor treatment were correlated significantly with a negative vaccination response, whereas younger age and chronic myeloid leukemia (CML) disease were associated with positive response. In addition, 5 of 6 patients with myeloproliferative neoplasm (MPN) and negative vaccination response were on active treatment with ruxolitinib. In conclusion, a remarkable percentage of patients with hematological diseases had no response after 2nd COVID-19 vaccination. Multivariable analysis revealed important factors associated with response to vaccination. The results may serve as a guide for better protection and surveillance in this vulnerable patient cohort.

The insertion site is the main risk factor for central venous catheter-related complications in patients with hematologic malignancies.

Central venous catheters (CVC) placed either via the internal jugular vein (IJV) or the subclavian vein (SCV) are routinely used in patients with hematologic malignancies. In this retrospective study, we systematically compared CVC-associated complications for both insertion sites, IJV and SCV. Between January 2011 and June 2013, all consecutive patients (n = 87) were included with at least one CVC (n = 153; n = 94 IJV; n = 59 SCV) at our institution due to induction/consolidation for AML/ALL or autologous hematopoietic cell transplantation (HCT). Primary study endpoints were central line-associated (CLABSI), catheter-related (CRBSI) blood stream infections and local inflammation (LI) at the insertion site. CRBSI occurred earlier and more frequently in the IJV- versus the SCV-group with an incidence rate of CRBSI at day 15 of 10% versus 0% (p = .04) and a rate of CRBSI per 1000 CVC days of 5.7 versus 1.2. In addition, CLABSI was detected more often in IJV- compared to SCV-CVC (26% vs. 8%, p = .009). Conversely, LI occurred more frequently and earlier in SCV- versus IJV-CVC (88% vs. 56%, p < .0001) with a median time to LI of 9 versus 14 days (p < .0001). The strongest risk factor for the endpoints CRBSI, CLABSI, and LI was the insertion site. However, SCV insertion was a risk factor for LI (p = .001, HR: 2.0), insertion in the IJV a risk factor for CLABSI (p = .044, HR: 2.7) and CRBSI (p = .036, HR: 5.4). These results demonstrate a differential effect of the insertion site of CVC in neutropenic patients with a significantly reduced frequency of CVC-related blood stream infections in SCV-CVC.

Topical Treatment of Acyclovir-Resistant Herpes Simplex Virus Stomatitis after Allogeneic Hematopoietic Cell Transplantation.

INTRODUCTION: We report on patients who developed severe acyclovir-resistant (ACVr) herpes simplex virus 1 (HSV-1) stomatitis after allogeneic hematopoietic cell transplantation (HCT). PATIENTS: HCT patients suffering from HSV-1 stomatitis without response after 1 week of high-dose acyclovir (ACV) were tested for ACV resistance. Patients with proven ACV resistance were treated either topically with cidofovir solution and gel or with topical foscavir cream or with intravenous foscavir. RESULTS: Among 214 consecutive HCT patients, 6 developed severe ACVr HSV-1 stomatitis (WHO grade III n = 1, WHO grade IV n = 5). All 6 patients suffered from relapse of acute myeloid leukemia (AML) after HCT. ACVr stomatitis was treated topically with first-line (n = 4) or second-line (n = 2) cidofovir. Topical foscavir cream was applied as first-line (n = 1) or second-line (n = 1) therapy. Intravenous foscavir was used in 3 patients (first-line therapy, n = 1; second-line therapy, n = 2). Complete remission was reached by topical cidofovir (n = 3), topical foscavir (n = 1), and intravenous foscavir (n = 1), respectively. Five of the 6 patients died due to progression of leukemia. Only 1 patient survived. CONCLUSIONS: ACVr HSV-1 stomatitis is a severe complication in AML patients relapsing after HCT. It reflects the seriously impaired general condition of these patients. This analysis shows that topical treatment with cidofovir or foscavir might be a sufficient first-line therapy approach in ACVr HSV-1 stomatitis. It might serve as a less toxic alternative to intravenous foscavir.

Influence of the Insertion Site on Central Venous Catheter-Related Complications in Patients Undergoing Allogeneic Hematopoietic Cell Transplantation.

Central venous catheters (CVCs) are extensively used in patients undergoing allogeneic hematopoietic cell transplantation (HCT). In these patients CVC are placed routinely either via the internal jugular vein (IJV) or the subclavian vein (SCV). Purpose of this study was to systematically analyze complications of CVC at different insertion sites in HCT recipients. In this retrospective analysis, all consecutive patients (n = 56) who received a CVC (n = 101) due to allogeneic HCT at our institution between January 2011 and June 2013 were included. Three-lumen standard, nontunneled CVCs were placed via either the IJV (n = 60; 59%) or the SCV (n = 41; 41%). Study endpoints were time to local inflammation at the insertion site, time to fever, time to a combined endpoint of inflammation and fever, central line-associated bloodstream infection (CLABSI), duration of catheterization, catheter lumen obstruction, deep-vein thrombosis, pneumothorax, and catheter-related death. The median duration of catheterization per CVC was almost identical for the IJV and SCV sites (18 days versus 17 days; P not significant). There were no differences in the frequency of CLABSI, deep-vein thrombosis, pneumothorax, and catheter lumen obstruction between IJV and SCV CVC insertion sites. None of the patients died due to a CVC-related cause. Local inflammation occurred less frequently (48% versus 71%; P = .025) and later (median time to local inflammation, 25 days versus 12 days; P = .01) in IJV CVCs versus SCV CVCs. There was a trend toward a median longer time to the occurrence of fever for IJV CVCs compared with SCV CVCs (20 days versus 13 days; P = .07). In the multivariate analysis, diagnosis of acute leukemia (hazard ratio [HR], 1.696; P = .036), SCV CVC (HR, 1.617; P  = .039), and neutropenic CVC-days (HR, 2.477; P = .01) were identified as risk factors for the occurrence of local inflammation or fever. In contrast to earlier studies in patients without hematologic malignancies, these data demonstrate that CVCs placed in the SCV are not superior over IJV CVCs. Moreover, local inflammation occurred earlier and more frequently in patients with an SCV CVC.

Course of colonization by multidrug-resistant organisms after allogeneic hematopoietic cell transplantation.

Multidrug-resistant organisms (MDRO) have been developing as an emerging problem in allogeneic hematopoietic cell transplantation (HCT). Since no data are available on the course of MDRO colonization after HCT, we investigated in this retrospective, single-center study, persistence and clearance of MDRO after HCT. From June 2010 to December 2015, 121 consecutive HCT patients were included. Patients received a MDRO screening before conditioning as well as surveillance cultures after HCT. In MDRO-colonized patients, surveillance specimens were taken until MDRO were no longer detectable. Thirty-three patients (27%) were found to be colonized by at least one MDRO at any time point until day 100 post HCT. Day 100 (2-year) non-relapse mortality (NRM) and overall survival (OS) of MDRO-colonized (MDRO+) versus non-colonized (MDRO-) patients were essentially the same. NRM is 15% (21%) versus 15% (24%). Two-year OS is 60 versus 55% for MDRO+ versus MDRO- patients. Out of the 33 MDRO+ patients, 21 cleared the MDRO. Median time to non-detectability of MDRO was 6 months. In 12 patients, the MDRO persisted. There was a significant (p < 0.0001) survival difference between patients who cleared the MDRO versus those with MDRO persistence (2-year OS 80 vs 40%). Except for the length of antibiotic therapy as a potential risk factor for MDRO persistence after HCT, no other conventional factors could be identified. (a) colonization by MDRO per se had no negative impact on the outcome, (b) MDRO can be cleared by the majority of patients after allogeneic HCT, and (c) to increase the probability to clear MDRO, the use of antibiotics in MDRO+ patients should be reviewed critically.

Enhanced labile plasma iron and outcome in acute myeloid leukaemia and myelodysplastic syndrome after allogeneic haemopoietic cell transplantation (ALLIVE): a prospective, multicentre, observational trial.

BACKGROUND: The effect of systemic iron overload on outcomes after allogeneic haemopoietic cell transplantation (HCT) has been a matter of substantial debate. We aimed to investigate the predictive value of both stored (MRI-derived liver iron content) and biologically active iron (enhanced labile plasma iron; eLPI) on post-transplantation outcomes in patients with acute myeloid leukaemia or myelodysplastic syndrome undergoing allogenic HCT. METHODS: The prospective, multicentre, observational, ALLogeneic Iron inVEstigators (ALLIVE) trial recruited patients at five centres in Germany. We enrolled patients with acute myeloid leukaemia or myelodysplastic syndrome undergoing allogeneic HCT. Patients underwent cytotoxic conditioning for a median of 6 days (IQR 6-7) before undergoing allogeneic HCT and were followed up for up to 1 year (±3 months) post-transplantation. eLPI was measured in serum samples with the FeROS eLPI kit (Aferrix, Tel-Aviv, Israel) and values greater than 0·4 µmol/L were considered to represent raised eLPI. Liver iron content was measured by MRI. The primary endpoints were the quantitative delineation of eLPI dynamics during allogeneic HCT and the correlation coefficient between liver iron content before HCT and dynamic eLPI (eLPIdyn; maximum eLPI minus baseline eLPI). All patients with available data were included in all analyses. This is the final analysis of this completed trial, which is registered with ClinicalTrials.gov, number NCT01746147. FINDINGS: Between Dec 13, 2012, and Dec 23, 2014, 112 patients underwent allogeneic HCT. Liver iron content before allogeneic HCT was not significantly correlated with eLPIdyn (ρ=0·116, p=0·22). Serum eLPI concentrations rapidly increased during conditioning, and most (79 [73%] of 108) patients had raised eLPI by the day of transplantation. Patients with a pretransplant liver iron content greater than or equal to 125 µmol/g had an increased incidence of non-relapse mortality (20%, 95% CI 14-26) compared with those with lower concentrations (7%, 2-12; p=0·039) at day 100. Patients who had raised eLPI at baseline also had a significantly increased incidence of non-relapse mortality at day 100 (33%, 15-52) compared with those who had normal eLPI at baseline (7%, 2-13; p=0·00034). INTERPRETATION: eLPI is a possible biological mediator of iron-related toxicity. Peritransplantation eLPI-scavenging strategies could be explored in prospective interventional clinical trials for patients with systemic iron overload. FUNDING: The Technical University of Dresden and Novartis.

Multidrug-resistant organisms in allogeneic hematopoietic cell transplantation.

OBJECTIVE: Multidrug-resistant organisms (MDRO) are a challenge in allogeneic hematopoietic cell transplantation (HCT). However, in the literature there is no comprehensive analysis on MDRO in HCT. In this retrospective, single-center analysis, we appraised prevalence and clinical impact of MDRO in 98 consecutive allogeneic HCT patients. METHOD: Prior to the conditioning (baseline) and whenever clinically indicated patients underwent a full screening for MDRO (stool and urine cultures, swabs from several body regions). RESULTS: It turned out that 26 patients were colonized by 33 MDRO, either at baseline (n=16) or at any other time until day 100 post-transplantation. Of these 26 patients, eight developed an infection with MDRO, four of them by 4MRGN Pseudomonas aeruginosa, and three of them died MDRO-related. However, there was no significant difference between MDRO-colonized and non-colonized patients regarding overall survival (OS) and non-relapse-mortality (NRM). There was only a trend toward a higher NRM in patients already colonized by MDRO at baseline. This was due to the high NRM in multidrug-resistant P. aeruginosa-colonized patients. CONCLUSION: In summary, colonization with MDRO other than P. aeruginosa had no negative impact on NRM and OS. Patients colonized by multidrug-resistant P. aeruginosa had a dismal outcome. HCT of these patients should be considered with care. Screening for MDRO in the pretransplant work-up is suggested.

Assessment of acute intestinal graft versus host disease by abdominal magnetic resonance imaging at 3 Tesla.

OBJECTIVES: After allogeneic stem cell transplantation (SCT), a reliable diagnosis of acute graft versus host disease (aGvHD) is essential for an early and successful treatment. It is the aim of this analysis to assess intestinal aGvHD by magnetic resonance imaging (MRI). METHODS: Prior to allogeneic SCT, 64 consecutive patients underwent abdominal MRI examination on a 3 T MR system, including axial and coronal T2w sequences and a three-dimensional dynamic T1w, contrast enhanced sequence. After SCT, 20 patients with suspected aGvHD received a second MRI as well as an endoscopic examination. RESULTS: Nine patients suffered from histologically proven intestinal aGvHD. In eleven patients intestinal aGvHD was excluded. In all aGvHD patients typical MRI findings with long-segment bowel wall thickening--always involving the terminal ileum--with profound submucosal oedema, were detected. The bowel wall was significantly thickened in patients with intestinal aGvHD. Bowel contrast enhancement spared the submucosa while demonstrating strong mucosal hyperemia. CONCLUSIONS: In intestinal aGvHD, a characteristic MR-appearance can be detected. This MRI pattern might facilitate an early and non-invasive diagnosis of intestinal aGvHD. MRI might thus be used as a sensitive tool to rule out or support the clinical diagnosis of aGvHD. KEY POINTS: • Acute intestinal graft versus host disease (aGvHD) can be assessed by MRI. • The aGvHD of the bowel demonstrates a characteristic MR imaging pattern. • Bowel wall shows extensive long-segment wall thickening with profound submucosal oedema. • Terminal ileum seems invariably affected; other bowel segments show variable involvement. • Colonoscopy in suspected aGvHD should include inspection of terminal ileum.

Long-term results of a prospective randomized trial evaluating G-CSF priming in intensive induction chemotherapy followed by autologous stem cell transplantation in elderly patients with acute myeloid leukemia.

Few studies have evaluated granulocyte colony-stimulating factor (G-CSF) priming in elderly patients with intensively treated acute myeloid leukemia (AML), and no data are available for genetically defined AML subgroups. We provide long-term results (median follow-up 7.6 years) of a randomized trial in which 183 patients (median age 67 years) received G-CSF prior to (G-CSF priming) or after two cycles of induction chemotherapy. CR rates with G-CSF priming and G-CSF post-chemotherapy were comparable (57 vs. 67 %, p = 0.153), with overall survival (OS) probabilities of 14 vs. 17 % at 10 years. Induction mortality was significantly higher with G-CSF priming (23 vs. 10 %, p = 0.015), primarily in normal karyotype (NK) AML. In this subgroup, a trend for better relapse-free survival (RFS) was observed with G-CSF priming (44 vs. 22 % at 10 years, p = 0.074) but did not translate into an OS benefit. G-CSF priming had no impact on AML with FLT3-ITD and NPM mutations and did not improve outcome in patients with adverse cytogenetics. In a landmark analysis, late consolidation with autologous stem cell transplantation or a second consolidation cycle significantly improved RFS compared with one consolidation cycle (21.0 vs. 12.8 months, p = 0.046). Future studies on G-CSF priming should be restricted to NK AML and used only in post-remission therapy.

Knockdown of ERM family member moesin in host cells increases HIV type 1 replication.

Moesin is a member of the ERM (ezrin, radixin, moesin) family of cytoskeleton/membrane structure organizing and signal transduction proteins. Previously, we found an increased expression of moesin during HIV-1 infection. Moesin was also reported to be incorporated into HIV-1 virions. To analyze whether moesin is a host factor affecting the replication cycle of human immunodeficiency virus type 1 (HIV-1), we used small interfering RNAs (siRNAs) to evaluate the effect of moesin knockdown on HIV-1 replication in P4-CCR5 cells. Moesin's knockdown did not affect the cell viability or cell phenotype. Interestingly, we observed a marked increase in viral replication, as demonstrated by enhanced HIV-1 RNA, p24 antigen, and ß-galactosidase reporter expression. Moesin-dependent enhancement of HIV-1 replication was confirmed in lymphocytic host cells (Jurkat). These results suggest an overall rather restrictive role of moesin for HIV-1 replication in host cells in vitro.

Identification and characterization of a highly efficient anti-HIV pol hammerhead ribozyme.

The aim of this study was to identify and to characterize a highly active anti-HIV ribozyme. Therefore, the genome of HIV-1 IIIb was screened for not yet addressed GUC triplets within highly conserved sequences. Here we report the in vitro characteristics and the antiviral activity of the fittest identified anti-HIV hammerhead ribozyme, targeting the 13th GUC triplet within the HIV-1 pol gene (HHPol13). Multiple turnover kinetics were determined in vitro and revealed very promising kinetic data: V(max) = 39 nM/minute, K(m) = 576 nM, k(cat) = 3.9/minute, and K(cat)/K(m) = 6.8/minute/microM. To analyze its antiviral activity the hammerhead ribozyme was expressed retrovirally in Hut78 cells followed by HIV-1 infection. The newly identified ribozyme conferred a long-term inhibition of HIV-1 replication until the end of the observation period at day 56. We were able to demonstrate that the antiviral activity was mainly due to a ribozyme effect combined with a limited antisense activity. Additionally, the effect of the identified ribozyme was compared with a retrovirally expressed siRNA directed against the same target in the HIV-1 pol gene. This siRNA (siPol13) showed no inhibition of HIV replication. In summary, the hammerhead ribozyme HHPol13 was demonstrated to confer superior cleavage and antiviral activity against HIV-1. These results suggest that even in the RNAi era ribozymes still have the potential as highly active antiviral agents.

High-dose melphalan is an effective salvage therapy in acute myeloid leukaemia patients with refractory relapse and relapse after autologous stem cell transplantation.

In a pilot study high-dose melphalan (HD-Mel, 200 mg/m2) and autologous stem cell transplantation (ASCT) were administered to 14 patients (median age 52, range 29-60 years) with acute myeloid leukaemia (AML) in first relapse after a previous ASCT in first complete remission (n=11) or chemotherapy (n=3). A first cohort of five patients received HD-Mel as salvage therapy after a previous cycle of mitoxantrone, topotecan and cytarabine (MTC) had failed in four out of five patients, while a second cohort of nine patients received HD-Mel in untreated relapse. Thirteen (93%) of 14 patients achieved a second complete remission (CR2), including all four patients who had been refractory to MTC. No treatment-related mortality was observed after HD-Mel. Thirteen (93%) patients were able to proceed to a dose-reduced allogeneic stem cell transplantation (allo-SCT) from human-leucocyte-antigens-compatible unrelated (n=12) or sibling donors (n=1) in CR2 (n=11) or poor recovery/relapse (n=2) after a median of 2 (1.7-4.5) months following HD-Mel. Three MTC-refractory patients, but none of the upfront HD-Mel patients, died due to an allograft-related non-relapse cause. Nine patients are alive in CR2 after a median of 6 (2-49) months after HD-Mel and a median of 4 (0.6-47) months after a sequential allo-SCT. Although median follow-up is still short, the proportion of patients achieving a CR2, as well as of those proceeding to a subsequent reduced-intensity-conditioning-allo-SCT, is superior to those previously reported. Our results highly encourage to further investigate HD-Mel and ASCT as a promising salvage regimen for relapsed AML patients for whom autologous peripheral blood stem cells are available.

Prophylactic and interventional granulocyte transfusions in patients with haematological malignancies and life-threatening infections during neutropenia.

Patients with haematological malignancies and prolonged periods of neutropenia after chemotherapy are at high risk for severe bacterial and fungal infections. Those infections have long time been considered as a contraindication for subsequent haematopoietic stem cell transplantation (HCT). We conducted a prospective, non-randomized study of granulocyte transfusions (GTX) to control acute life-threatening infections (44 episodes) and to prevent recurrence of severe fungal infections during HCT or intensive chemotherapy (23 episodes). GTX achieved control in 82% (36/44) of acute life-threatening infections. No single reactivation of a previous infection occurred under prophylactic GTX (0/23). Median survival was 170 days in the interventional group and 185 days in the prophylactic group; death in both patient groups was mainly due to underlying progressive malignant disease. We conclude that under GTX, the infection-related mortality even in high-risk patients is low. Due to a secondary prophylaxis with GTX, haematopoietic allografts can be safely given to patients with previous fungal infections.

Re-186 HEDP conditioning therapy in patients with advanced acute lymphoblastic leukemia before allogeneic bone marrow transplantation.

The authors present their experience with dose calculation of Retin1,1-hydroxyethylidene-186-diphosphonate (Re-186 HEDP) therapy used as part of an intensified conditioning regimen before allogeneic stem cell transplantation in 2 patients with advanced acute lymphoblastic leukemia during the second partial or third complete remission. Kidneys were shielded during total-body irradiation (TBI) to limit the TBI-mediated renal radiation dose to 7 Gy. The aim of this dose calculation of Re-186 HEDP therapy was to deliver additional radiotherapy to the red bone marrow without exposing more than an additional 5 Gy to the kidneys in addition to the TBI standard dose of 12.6 Gy. Pretherapeutic kidney scintigraphy (Tc-99m mercaptoacetyltriglycine) showed normal results. Thus, dynamic Tc-99m methylene diphosphonate bone scintigraphy was used to calculate the expected bone marrow and kidney doses. A total amount of 8.8 GBq (238 mCi) Re-186 HEDP was given to patient no. 1 and 14.3 GBq (387 mCi) Re-186 HEDP was given to patient no. 2. Re-186 HEDP activity was monitored based on its gamma radiation measurement daily for 5 days in patient no. 1 and 7 days in patient no. 2. Therapeutic Re-186 isotope distribution and biologic half-life correlated well with the prediction by a pretherapeutic Tc-99m methylene diphosphonate scan. The calculated effective Re-186 bone marrow dose was 3.3 Gy for patient no. 1 and 5.6 Gy for patient no. 2. Effective kidney doses were 1.6 Gy and 2.1 Gy respectively. No unexpected complications occurred after completing conditioning and allogeneic stem cell transplantation. Posttransplant kidney function remained normal. Patient no. 1 remains in a second complete remission of his advanced acute lymphoblastic leukemia 18 months after HEDP therapy. Patient no. 2 relapsed 5 months after transplantation and eventually died as a result of progressive disease. The authors conclude that Re-186 HEDP will be able to increase the total additional bone marrow dose. In patients in whom the kidney dose is limited to 5 Gy in addition to TBI, doses near 10 Gy can be achieved on the bone marrow.

Comparison of TaqMan real-time PCR and p24 Elisa for quantification of in vitro HIV-1 replication.

In this study, TaqMan PCR was used to assess viral replication of HIV-1 infected cells in vitro. This PCR technique was compared with p24 ELISA as a standard method to monitor HIV-1 replication in cell culture. Hut78 T-lymphoblastoid cells were infected with different titres of HIV-1(IIIb) (MOI 0.05-0.0005). The course of HIV-1 replication was monitored by determination of p24 concentrations by ELISA in cell culture supernatants and by quantitation of HIV-1 gag RNA by TaqMan RT-PCR. Additionally, the number of HIV-1 proviral copies was assessed by TaqMan PCR. Monitoring of HIV-1 replication by p24 ELISA and TaqMan RT-PCR revealed comparable kinetics of infection. Both methods provided similar data on the exponential increase and on plateauing of HIV-1 replication. Furthermore, both methods were equally sensitive. However, a 7 log linearity of TaqMan HIV-1 gag PCR was demonstrated without dilution of the specimen, in contrast to p24 ELISA, where because of its narrow range of detectable p24 concentrations, sample dilution was necessary. Although determination of the number of proviral copies by TaqMan PCR does not measure HIV-1 replication, the kinetics of proviral copy number following in vitro inoculation of cells with HIV-1 was nearly the same as the kinetics of HIV-1 RNA copy numbers. In conclusion, TaqMan real-time RT-PCR was demonstrated as a reliable and sensitive tool to quantify and monitor HIV-1 replication in cell culture. It is suggested, therefore, that this technique be an alternative method to monitor HIV-1 replication in vitro.