Prevalence and significance of bacterial contamination of autologous stem cell products

There is limited and conflicting information on the prevalence of contamination of haematopoietic stem and progenitor cell products (HPCPs), and their optimal management remains unclear. The authors reviewed the microbial surveillance data of HPCPs collected between January 2002 and December 2019 for autologous transplantation at the study institution to determine the prevalence of microbial contamination and the potential infectious complications among recipients. Among 3935 HPCPs, 25 (0.6%) were contaminated. Ultimately, 22 patients received contaminated grafts, with pre-emptive antimicrobial therapy initiated in six of these patients. No patients developed subsequent infectious complications. These data suggest that microbial contamination of autologous HPCPs and associated adverse outcomes are rare.

Lenalidomide added to standard intensive treatment for older patients with AML and high-risk MDS

More effective treatment modalities are urgently needed in patients with acute myeloid leukemia (AML) of older age. We hypothesized that adding lenalidomide to intensive standard chemotherapy might improve their outcome. After establishing a safe lenalidomide, dose elderly patients with AML were randomly assigned in this randomized Phase 2 study (n = 222) to receive standard chemotherapy ("3 + 7") with or without lenalidomide at a dose of 20 mg/day 1-21. In the second cycle, patients received cytarabine 1000 mg/m² twice daily on days 1-6 with or without lenalidomide (20 mg/day 1-21). The CR/CRi rates in the two arms were not different (69 vs. 66%). Event-free survival (EFS) at 36 months was 19% for the standard arm versus 21% for the lenalidomide arm and overall survival (OS) 35% vs. 30%, respectively. The frequencies and grade of adverse events were not significantly different between the treatment arms. Cardiovascular toxicities were rare and equally distributed between the arms. The results of the present study show that the addition of lenalidomide to standard remission induction chemotherapy does not improve the therapeutic outcome of older AML patients. This trial is registered as number NTR2294 in The NederlandsTrial Register (www.trialregister.nl).

Postremission Consolidation by Autologous Hematopoietic Cell Transplantation (HCT) for Acute Myeloid Leukemia in First Complete Remission (CR) and Negative Implications for Subsequent Allogeneic HCT in Second CR: A Study by the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation (EBMT)

After autologous hematopoietic cell transplantation (HCT) in the first complete remission (CR1), patients with acute myeloid leukemia (AML) may relapse and undergo allogeneic HCT in the second complete remission (CR2). The aim of this study was to analyze the outcome of allogeneic HCT performed in CR2 comparing patients with prior consolidation by autologous HCT versus patients with chemotherapy consolidation. Included were 2619 adults with allogeneic HCT in CR2 from 2000 to 2017 with (n = 417) or without (n = 2202) prior autologous HCT. Patient groups were not entirely comparable; patients with prior autologous HCT were younger, had less often a favorable cytogenetic profile, had more commonly donors other than matched siblings, and more often received reduced-intensity conditioning. In multivariate analysis, nonrelapse mortality risks in patients with prior autologous HCT were 1.34 (1.07 to 1.67; P = .01) after adjustment for age, cytogenetic risk, transplant year, donor, conditioning intensity, sex matching, interval diagnosis-relapse, and relapse-allogeneic HCT as compared with chemotherapy consolidation. Similarly, risks of events in leukemia-free survival and graft-versus-host disease, relapse-free survival were higher with prior autologous HCT, 1.17 (1.01 to 1.35), P = .03 and 1.18 (1.03 to 1.35), P = .02, respectively. Risk of death was also higher, 1.13 (0.97 to 1.32), P = .1, but this was not significant. Postremission consolidation with autologous HCT for AML in CR1 increases toxicity of subsequent allogeneic HCT in CR2.

Nelfinavir and lenalidomide/dexamethasone in patients with lenalidomide-refractory multiple myeloma. A phase I/II Trial (SAKK 39/10)

The antiretroviral agent nelfinavir has antimyeloma activity and can overcome resistance to bortezomib. Our phase I/II trial investigated whether adding nelfinavir to lenalidomide-dexamethasone can overcome lenalidomide resistance in lenalidomide-refractory multiple myeloma (MM). Twenty-nine patients were included (high-risk cytogenetic aberrations 31%; ≥2 prior therapy lines 93%; lenalidomide-bortezomib double-refractory 34%). Twenty-four patients (83%) had prior bortezomib and 10 (34%) were lenalidomide-bortezomib double-refractory. They received four cycles of nelfinavir 2500 mg/day with standard-dose lenalidomide (25 mg days 1-21) and dexamethasone (40/20 mg days 1, 8, 15, 22). Minor response or better was achieved in 16 patients (55%; 95% CI 36-74%), including 40% of those who were lenalidomide-bortezomib double-refractory, and partial response or better in nine patients (31%; 95% CI 15-51%). Median progression-free survival was 3.4 (95% CI 2.0-4.9) months and median overall survival 21.6 (13.0-50.1) months. Lenalidomide-related pneumonitis, pneumonia, and neutropenic fever occurred, but there were no unexpected adverse events. Peripheral blood mononuclear cells showed a 45% (95% CI 40-51%) reduction in total proteasome activity from baseline and significant induction of unfolded protein response and autophagy. Thus, nelfinavir-lenalidomide-dexamethasone is an active oral combination in lenalidomide-refractory MM.

Diagnostik der Enzootischen Pneumonie in Schweineherden nach Impfung gegen Mycoplasma hyopneumoniae

Ziel: Verlaufsuntersuchungen bei Ferkeln sollten zeigen, wie sich der Status von M.-hyopneumoniae-Infektionen mittels PCR im Vergleich zu serologischen und klinischen Untersuchungen darstellt. Material und Methoden: In zwei konventionellen Ferkelerzeugerbeständen wurden Ferkel aus je vier Abferkelgruppen (Herde 1: n = 360, Herde 2: n = 440) zufällig einer von drei Gruppen zugeordnet und einmalig in der 4. Lebenswoche (LW) mit Ingelvac® M.hyo oder in der 1. und 4. LW mit Stellamune® geimpft. Die Kontrollgruppe erhielt in der 1. und 4. LW eine Injektion physiologischer Kochsalzlösung. In vierwöchigen Intervallen (4.-20. LW) wurde bei zufällig ausgewählten 12 Tieren eine bronchioalveoläre Lavage durchgeführt und die Lavageflüssigkeit mittels One-step-PCR auf Genomfragmente von M. hyopneumoniae (M. hyo.) untersucht. Gleichzeitig wurden Serumproben von 45 Schweinen der drei Gruppen mit einem indirekten Tween-20-ELISA auf Antikörper gegen M. hyo. getestet. Klinische Untersuchungen erfolgten ebenfalls in vierwöchigen Intervallen und das Vorkommen von Husten wurde anhand eines Hustenindex dokumentiert. Die klinischen und serologischen Untersuchungen fanden bis zur 24. LW statt. Ergebnisse: In vier der acht Gruppen ließ sich M. hyo. mittels PCR in der 16. und 20. LW mit durchschnittlichen Prävalenzen von 0,13 und 0,62 nachweisen. Gleichzeitig erfolgte ein signifikanter (p < 0,0001) Anstieg des Hustenindex, während eine Serokonversion mit vierwöchiger Verzögerung in der 20. und 24. LW festzustellen war. In den restlichen vier Gruppen war M. hyo. mittels PCR nicht nachzuweisen. Eine Serokonversion war ebenfalls nicht festzustellen und der Hustenindex lag in der 16. und 20. Lebenswoche signifikant (p = 0,001) unter den Werten der infizierten Gruppen. Schlussfolgerung: Die enge zeitliche Übereinstimmung zwischen dem Auftreten typischer Symptome und dem Erregernachweis zeigt, dass sich die Untersuchung von bronchioalveolärer Lavageflüssigkeit mit einer One-step-PCR für die Diagnostik der Enzootischen Pneumonie eignet.

Comparative value of post-remission treatment in cytogenetically normal AML subclassified by NPM1 and FLT3-ITD allelic ratio

Post-remission treatment (PRT) in patients with cytogenetically normal (CN) acute myeloid leukemia (AML) in first complete remission (CR1) is debated. We studied 521 patients with CN-AML in CR1, for whom mutational status of NPM1 and FLT3-ITD was available, including the FLT3-ITD allelic ratio. PRT consisted of reduced intensity conditioning (RIC) allogeneic hematopoietic stem cell transplantation (alloHSCT) (n=68), myeloablative conditioning (MAC) alloHSCT (n=137), autologous hematopoietic stem cell transplantation (autoHSCT) (n=168) or chemotherapy (n=148). Favorable overall survival (OS) was found for patients with mutated NPM1 without FLT3-ITD (71±4%). Outcome in patients with a high FLT3-ITD allelic ratio appeared to be very poor with OS and relapse-free survival (RFS) of 23±8% and 12±6%, respectively. Patients with wild-type NPM1 without FLT3-ITD or with a low allelic burden of FLT3-ITD were considered as intermediate-risk group because of similar OS and RFS at 5 years, in which PRT by RIC alloHSCT resulted in better OS and RFS as compared with chemotherapy (hazard ratio (HR) 0.56, P=0.022 and HR 0.50, P=0.004, respectively) or autoHSCT (HR 0.60, P=0.046 and HR 0.60, P=0.043, respectively). The lowest cumulative incidence of relapse (23±4%) was observed following MAC alloHSCT. These results suggest that alloHSCT may be preferred in patients with molecularly intermediate-risk CN-AML, while the choice of conditioning type may be personalized according to risk for non-relapse mortality.

Varicella zoster virus reactivation after autologous SCT is a frequent event and associated with favorable outcome in myeloma patients

The occurrence of varicella zoster virus (VZV) reactivation is increased after allogeneic transplantation, whereas limited data are available for herpes zoster (HZ) after autologous SCT (ASCT). We determined the incidence and the prognostic significance of HZ and its correlation with VZV serology in 191 consecutive myeloma patients undergoing high-dose melphalan chemotherapy with ASCT. We found that VZV reactivation occurred in 57 (30%) patients, in 8.5% during induction and in 21.5% after ASCT peaking at 8 months after ASCT. Disease burden due to HZ was assessed as high or rather high in 70% of the patients. By immune fluorescence and Serion Elisa VZV IgG assessment, 90.8% of all patients had specific anti-VZV antibodies at ASCT. Lower specific antibody titers at transplantation were observed in patients with HZ after ASCT than in those without reactivation (P=0.009). Finally, OS was better in myeloma patients with HZ after ASCT compared with patients without HZ (P=0.007). Our data indicate that VZV reactivation after ASCT is a frequent event carrying a significant disease burden and it is associated with improved survival. Low levels of specific VZV antibodies at ASCT suggest increased vulnerability for VZV reactivation.

Resistance prediction in AML: analysis of 4601 patients from MRC/NCRI, HOVON/SAKK, SWOG and MD Anderson Cancer Center

Therapeutic resistance remains the principal problem in acute myeloid leukemia (AML). We used area under receiver-operating characteristic curves (AUCs) to quantify our ability to predict therapeutic resistance in individual patients, where AUC=1.0 denotes perfect prediction and AUC=0.5 denotes a coin flip, using data from 4601 patients with newly diagnosed AML given induction therapy with 3+7 or more intense standard regimens in UK Medical Research Council/National Cancer Research Institute, Dutch-Belgian Cooperative Trial Group for Hematology/Oncology/Swiss Group for Clinical Cancer Research, US cooperative group SWOG and MD Anderson Cancer Center studies. Age, performance status, white blood cell count, secondary disease, cytogenetic risk and FLT3-ITD/NPM1 mutation status were each independently associated with failure to achieve complete remission despite no early death ('primary refractoriness'). However, the AUC of a bootstrap-corrected multivariable model predicting this outcome was only 0.78, indicating only fair predictive ability. Removal of FLT3-ITD and NPM1 information only slightly decreased the AUC (0.76). Prediction of resistance, defined as primary refractoriness or short relapse-free survival, was even more difficult. Our limited ability to forecast resistance based on routinely available pretreatment covariates provides a rationale for continued randomization between standard and new therapies and supports further examination of genetic and posttreatment data to optimize resistance prediction in AML.

Integrating novel agents into multiple myeloma treatment - current status in Switzerland and treatment recommendations

The treatment of multiple myeloma has undergone significant changes in the recent past. The arrival of novel agents, especially thalidomide, bortezomib and lenalidomide, has expanded treatment options and patient outcomes are improving significantly. This article summarises the discussions of an expert meeting which was held to debate current treatment practices for multiple myeloma in Switzerland concerning the role of the novel agents and to provide recommendations for their use in different treatment stages based on currently available clinical data. Novel agent combinations for the treatment of newly diagnosed, as well as relapsed multiple myeloma are examined. In addition, the role of novel agents in patients with cytogenetic abnormalities and renal impairment, as well as the management of the most frequent side effects of the novel agents are discussed. The aim of this article is to assist in treatment decisions in daily clinical practice to achieve the best possible outcome for patients with multiple myeloma.

The tumour-suppressive miR-29a/b1 cluster is regulated by CEBPA and blocked in human AML

BACKGROUND

CCAAT/enhancer-binding protein-alpha (CEBPA) is crucial for normal granulopoiesis and is frequently disrupted in acute myeloid leukaemia (AML). Increasing evidence suggests that CEBPA exerts its effects, in parts, by regulating specific microRNAs (miRNAs), as previously shown for miR-223. The aim of this study was to investigate the genome-wide pattern of miRNAs regulated by CEBPA in myeloid cells.

METHODS

In Kasumi-1 cells, conditionally expressing CEBPA, we assessed the expression of 470 human miRNAs by microarray analysis. We further investigated the microarray results by qRT-PCR, luciferase reporter assays, and chromatin immunoprecipitation assays.

RESULTS

In all, 18 miRNAs were more than two-fold suppressed or induced after CEBPA restoration. Among these 18 miRNAs, we focused on CEBPA-mediated regulation of the tumour-suppressive miR-29b. We observed that miR-29b is suppressed in AML patients with impaired CEBPA function or loss of chromosome 7q. We found that CEBPA selectively regulates miR-29b expression on its miR-29a/b1 locus on chromosome 7q32.3, whereas miR-29b2/c on chromosome 1q32.2 is not affected.

CONCLUSION

This study reports the activation of the tumour-suppressive miR-29b by the haematopoietic key transcription factor CEBPA. Our data provide a rationale for miR-29b suppression in AML patients with loss of chromosome 7q or CEBPA deficiency.

Implementation of the JACIE standards for a haematopoietic progenitor cell transplantation programme: a cost analysis

The purpose of the present project was to analyse the costs incurred by the implementation of JACIE standards at a University Hospital with 1000 beds, performing some 40 autologous transplants per year. The cost analysis was performed on the basis of a prospective assessment of the time spent by all staff members involved with the implementation over a 14-month period of the quality management system (QMS) required by the JACIE standards. Two physicians worked on JACIE Section A (management=82 h), one physician and two nurses for section Ba (clinical unit adults=125.75 h), two physicians and three nurses for section Bp (clinical unit paediatrics=206 h), one physician, two nurses and one technician for section C (progenitor cell collection facility=105.75 h), and one physician and two technicians for section D (progenitor cell processing facility=426 h). The total time spent on the project amounted to 945.5 h with a total salary cost of \[euro]150 000. We concluded that implementation of the JACIE standards was accomplished within a 14-month period with a financial impact of approximately \[euro]150 000. The impact on quality parameters (eg clinical and laboratory end points, side effects) on HPC transplantation will be assessed in a second report after the first year of practical implementation.

First results of long-term rituximab maintenance treatment in follicular lymphoma: Safety analysis of the randomized phase III trial SAKK 35/03

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Background: Rituximab maintenance has been shown to be effective in patients with follicular lymphoma. The optimal duration of maintenance remains unknown. Methods: We prospectively registered 270 patients with untreated, chemotherapy resistant or relapsed follicular lymphoma. All patients received rituximab induction consisting of 4 weekly doses (375 mg/m2). Responding patients (PR and CR) were randomized to a short maintenance consisting of four doses of rituximab (375 mg/m2) every two months (arm A) or prolonged maintenance consisting of rituximab every two months for a maximum of five years or until progression or unacceptable toxicity (arm B). Primary endpoint was event-free survival. Here we present the safety analysis. Results: From October 2004 to November 2007 165 patients were randomized, 82 in arm A and 83 in arm B. The median follow up is 22.7 months. A total of 442 hematological and non-hematological adverse events were observed, 27 of grade 3 and 6 of grade 4. Five subsequent cancers and 9 grade 3 and 4 infections were reported. Grade 3 and 4 neutropenia occurred in 5 patients, decreased levels of IgG were observed in 19 patients. Four grade 3 infections occurred after 2 years of maintenance. In arm B, maintenance was stopped due to unacceptable toxicity (fever) in 1 patient after 18 months and due to subsequent breast cancer in 1 patient after 20 months. One patient died 4 months after randomization because of ileus and consecutive peritonitis; considered to be unrelated to therapy. Twenty-nine patients are on maintenance for two or more years of which 6 patients are on for three or more years. In this analysis, median duration of the prolonged maintenance is 23.7 months. Conclusions: Rituximab maintenance beyond two years is feasible. We do not have evidence for increased toxicity after 2 years of maintenance. However, close follow up of patients under prolonged rituximab maintenance is necessary. The trial has been closed for accrual but there are still patients on treatment.

[Table: see text]

[MRI after renal transplantation with dysfunctional allograft: are there typical diagnoses in the early and late postoperative phases?]

PURPOSE

The aim of this study was to evaluate the different MRI diagnoses in the early and late post-operative period after renal transplantation with dysfunctional allograft.

MATERIALS AND METHODS

Due to unknown transplant dysfunction, 49 patients (30-male, 19 female) received a total of 74 MRI studies. According to the date of examination all MRI studies were divided in an early (< or = 60 days, ETP) and a late post-transplant time period (> 60 days, LTP). All MRI studies were performed on 1.5 T MRI systems using a standardised imaging protocol consisting of a morphological (pre- and post-contrast enhanced T (1)- and T (2)-weighted TSE sequences), a vascular (contrast-enhanced 3D MRA) and a urographical part (Flash 3D sequences). Frequencies of diagnoses in ETP and LTP, and diagnoses within each transplant time period were analysed.

RESULTS

44/74 MRI studies were performed in ETP, 30/74 in LTP. In total 80 diagnoses were obtained: Renal artery stenosis (ETP, n = 21; LTP, n = 5), renal vein stenosis (ETP, n = 2), renal vein thrombosis (ETP, n = 2), renal perfusion defect (ETP, n = 11), rejection (ETP, n = 1; LTP, n = 2), abscess (ETP, n = 1), urinary outflow obstruction (LTP, n = 4), without MRI pathology (ETP, n = 11; LTP, n = 20). Renal artery stenosis was the most prevalent diagnosis in ETP, and a more frequent finding in ETP compared to LTP (p < 0.05). Renal perfusion defects were more frequent in ETP than in LTP (p < 0.05). In the ETP vascular diseases (34/49 diagnoses) were more frequent (p < 0.05) than uropathological diseases (0/49 diagnoses).

CONCLUSIONS

Our results indicate that vascular diseases are a more frequent occurrence in the early post-operative course after renal transplantation than uropathological diseases. However, a transplant follow-up MRI study needs to contain a morphological, vascular and functional imaging part to answer combined clinical questions.

Mutations of the transcription factor PU.1 are not associated with acute lymphoblastic leukaemia

The transcription factor PU.1 plays a crucial role during normal haematopoiesis in both myeloid cells and B-lymphocytes. Mice with a disruption in both alleles of the PU.1 locus were found to lack macrophages and B cells and had delayed appearance of neutrophils. In addition, critical decrease of PU.1 expression is sufficient to cause acute myeloid leukaemia (AML) and lymphomas in mice. Recently, we reported that heterozygous mutations in the PU.1 gene are present in some patients with AML. Thus, we hypothesised that PU.1 mutations might also contribute to the development of acute leukaemias of the B-cell lineage. Here, we screened 62 patients with B-cell acute lymphoblastic leukaemia (B-ALL) at diagnosis for genomic mutations by direct sequencing of all five exons of the PU.1 gene. We found no genomic alteration of the PU.1 gene suggesting that PU.1 mutations are not likely to be common in B-ALL.

Diagnostik der Enzootischen Pneumonie in Schweineherden nach Impfung gegen Mycoplasma hyopneumoniae

Ziel: Anhand von Verlaufsuntersuchungen sollte gezeigt werden, wie sich der Serostatus von Schweinen interpretieren lässt, die nach verschiedenen Schemata gegen M. hyopneumoniae geimpft wurden. Material und Methoden: Untersuchung A: 186 Ferkel aus drei Erzeugerbetrieben wurden zufällig drei Behandlungsgruppen zugeteilt und in der 1. und 4. Lebenswoche (LW) resp. der 4. und 8. LW mit Hyoresp ® geimpft. Die Kontrollgruppe erhielt in der 1. und 4. LW physiologische Kochsalzlösung. Für die serologische Verlaufsuntersuchung wurde zwischen der 1. und 20. LW in vierwöchigen Intervallen Blut entnommen. Untersuchung B: In zwei Ferkelerzeugerbeständen wurden jeweils 180 Ferkel zufällig drei Behandlungsgruppen zugeordnet und einmalig in der 4. Woche mit Ingelvac® M.hyo bzw. in der 1. und 4. Woche mit Stellamune® geimpft. Die Kontrollgruppe erhielt in der 1. und 4. LW physiologische Kochsalzlösung. Die Blutprobenentnahme erfolgte zwischen der 4. und 24. LW. Die serologischen Untersuchungen wurden mittels eines indirekten Tween-20-ELISA durchgeführt. Ergebnisse: Während der ersten Lebenswochen waren überwiegend maternale Antikörper mit Prävalenzen um 0,8 (1. LW) und 0,45 bis 0,6 (4. LW) nachzuweisen. Die in der 1. und 4. resp. nur in der 4. LW geimpften Ferkel ließen in der 8. LW mit Prävalenzen zwischen 0,35 und 0,42 nur kurzzeitig eine Reaktion auf die Impfung erkennen. Bereits in der 12. LW waren zwischen den früh geimpften Ferkeln und den nicht geimpften Kontrolltieren keine Differenzen mehr feststellbar. Die Impfung konnte eine Infektion mit M. hyopneumoniae während der Mast nicht sicher verhindern. Bei geimpften Schweinen führt die Infektion zu einer merklich schnelleren und prägnanteren Reaktion, sodass die Seroprävalenz innerhalb von wenigen Wochen auf 0,8, bei den nicht geimpften Kontrolltieren aber nur auf 0,35 anstieg. Bei der Interpretation serologischer Befunde ist der Impfstatus daher unbedingt zu berücksichtigen. Schlussfolgerung: Die frühe Impfung lässt sich bei Läuferschweinen anhand serologischer Standardmethoden weder nachweisen noch ausschließen, was bei der Erstellung forensischer Gutachten zu berücksichtigen ist.

Detection of myocardial viability in acute infarction using contrast-enhanced 1H magnetic resonance imaging

BACKGROUND

Reperfusion strategies salvage myocardium at risk in acute myocardial infarction (MI). This clinical study was performed to determine whether areas without evidence of delayed MRI contrast enhancement in MI correspond to viability by means of percent systolic wall thickening (%SWT) and enddiastolic wall thickness (EDWT) in chronic infarction.

METHODS

Twenty MRI studies were performed in ten patients within 6 days of MI and 3 months post-MI. On a segmental basis the percentage of viable myocardium as defined by contrast-enhanced MRI (no delayed MRI contrast enhancement) in acute MI was measured and was compared with %SWT and EDWT in chronic MI.

RESULTS

Of the 1718 segments in acute infarction in which the percentage of viable myocardium was measured 1333 were found to be completely viable by means of contrast-enhanced MRI (no delayed MRI contrast enhancement). All of these segments revealed %SWT on day 90 post-MI, and 97% of segments were viable by means of an EDWT of more than 5.5 mm. In 85 segments the proportion of viable myocardium was 50-99% (mean 56+/-8%), with 92% segments found to be viable by means of %SWT and 92% by EDWT, and of 156 segments with viable myocardium between 1-49% (36+/-8%) 79% were found to be viable by means of %SWT and 82% by EDWT. Corresponding proportions of 144 segments with transmural delayed MRI contrast enhancement in acute MI were 45% and 17%.

CONCLUSIONS

In acute reperfused MI viable myocardium as delineated by contrast-enhanced MRI is correlated with clinical parameters of viability. Delayed MRI contrast enhancement resolves nontransmural MI and may become a valuable clinical tool when planning revascularization procedures.

[Primary diagnosis of coronary artery disease by MRI and CT]

Invasive coronary angiography is the gold standard for the primary diagnosis of coronary artery disease (CAD). At most, only every other examination leads to revascularization therapy. The other coronary angiographies could be replaced by non-invasive examinations. Diagnosing CAD by cardiac MRI and CT can utilize three different strategies: detection of coronary calcifications; imaging of coronary artery stenoses; and detection of restricted myocardial perfusion reserve. Applications are coronary calcification scoring by CT, coronary angiography by MRI or CT, stress cine MRI, and stress perfusion MRI. All these methods are currently used clinically because of their high negative predictive value, i.e., a normal result mostly rules out a hemodynamically significant CAD. For a reasonable implication in clinical practice, however, the pre-test probability must be considered to avoid needless examinations. High pre-test probability invariably demands invasive coronary angiography for planning or performing revascularization therapy. Intermediate pre-test probability, on the contrary, justifies to defer further imaging studies if MRI or CT is normal. Thus, adequate selection of patients for cardiac MRI and CT may reduce the number of invasive coronary angiographies in the future.

[Time-resolved MR angiography of the renal artery: morphology and perfusion]

PURPOSE

To prove the hypothesis that renal artery stenosis and changes in renal perfusion can be detected with contrast-enhanced time-resolved MR angiography in a single examination.

MATERIAL AND METHODS

In 71 patients, 137 renal arteries and 14 accessory renal arteries were studied. The examinations were performed on a 1.5 T system. A T 1 -weighted gradient echo sequence with a temporal resolution of 7 s was used. Single dose of contrast material (0.1 mmol/kg Gd-DTPA) was injected with a power injector with a flow rate of 2 ml/s. Criterion for the assessment of renal perfusion was the slope ratio of the signal intensity time curve in both kidneys.

RESULTS

Forty renal artery stenoses and one occlusion of a renal artery were detected. In 48 kidneys (35 %) segmental arteries were evaluated. The accuracy of the slope ratio (limit value 0.75) concerning the detection of unilateral renal artery stenosis was 92.6 % (sensitivity 75 %, specificity 95.7 %).

CONCLUSION

Time-resolved MR angiography can detect changes in renal perfusion in patients with unilateral renal artery stenosis.

[Interindividual-variability of the analysis of regional myocardial wall function after myocardial infarction and revascularization]

PURPOSE

The gold standard for diagnosis myocardial viability is the functional recovery after revascularization. Aim of the study was to compare (1) qualitative analysis and (2) quantitative wall thickening by cine MRI and (3) circumferential shortening by tagged MRI the analysis of regional wall function of an infarcted area before and after revascularization.

MATERIAL AND METHODS

Ten patients (age 60 +/- 11 years) with infarct-associated regional left ventricular wall motion abnormalities were examined by cine and tagged MRI on average two weeks after the myocardial infarction and re-examined three months after revascularization. Eight healthy volunteers served as a control for tagged MRI. Interobserver-variabilities of two observers were calculated using the kappa-statistics for grading of wall motion abnormalities as well as for detection of functional recovery by qualitative analysis, measurement of wall thickening of cine MRI, and measurement of circumferential shortening by tagged MRI, respectively.

RESULTS

Grading of wall motion abnormalities revealed interobserver-variabilities of the study and control group of kappa = 0.8 and kappa = 0.84, kappa = 0.02 and kappa = 0.5, and kappa = 0.1 and kappa = 0.17 for qualitative analysis, wall thickening analysis and measurement of circumferential shortening, respectively. The interobserver-variability for the definition of wall motion recovery was kappa = 0.8 for all three methods.

CONCLUSION

Qualitative analysis of wall motion abnormalities has the lowest interobserver-variability for the grading of wall motion abnormalities. The interobserver-variabilities of qualitative and quantitative analysis are comparable for the diagnosis of regional wall motion recovery. Thus, qualitative analysis of cine MRI can be used for grading regional wall motion in clinical studies.

High resolution contrast enhanced MR-angiography of the hand arteries: preliminary experiences

BACKGROUND

In contrast to magnetic-resonance-angiography (MRA) of the peripheral vessels of the lower extremity, which gains more and more clinical application, MRA of the hand arteries is still exceptional. Our objective was to introduce an appropriate protocol for high resolution contrast-enhanced MR-angiography of the hand arteries.

PATIENTS AND METHODS

7 healthy volunteers and 13 patients with suspected hand artery obstructions underwent MRA. The examinations were performed on a 1.5 T system equipped with a flexible surface coil. A modified 3D-gradient-echo sequence was used. Criteria for image analysis were the overall image quality, vessel visibility and the timing of the contrast material bolus.

RESULTS

In the volunteer group delineation of the superficial or deep palmar arch, common palmar digital arteries and of the proximal and middle segments of the digital arteries was possible. No pathologic findings were seen in the volunteer group. In 10 patients MRA revealed pathologic findings. In 9 examinations bolus-timing was correct, 7 examinations showed incomplete arterial enhancement, 4 examinations showed venous overlay.

CONCLUSIONS

Contrast enhanced MR-angiography of the hand arteries in the described technique is a promising method. Compared to intraarterial digital subtraction angiography (IA-DSA) MRA still has limitations concerning spatial and temporal resolution. For clinical evaluation comparative studies with IA-DSA are necessary.

Time course of contrast enhancement patterns after Gd-BOPTA in correlation to myocardial infarction and viability: a feasibility study

Our objective was to analyze contrast enhancement patterns (CEP) and their time course after myocardial infarction (MI) following injection of Gd-BOPTA in correlation with recovery of regional function. Seven patients with subacute MI (18 +/- nine days) were examined before, as well as three and six (n = six) months after, revascularization of the infarct-related artery. Regional wall motion abnormalities were assessed by cine-MRI, and repetitive images of one representative slice were acquired up to 45 minutes after 0.05 mmol/kg Gd-BOPTA using a T1-w TSE-sequence. Two patients showed mid-wall/subendocardial, one patient subendocardial enhancement of MI associated with mechanical improvement after revascularization. Three patients without improvement revealed a mid-wall hypoenhanced zone within the first five minutes after injection, which was unchanged at follow-up. One patient with partial functional improvement showed transmural enhancement and a mid-wall hypoenhanced zone in adjacent areas. With this feasibility study, we concluded that mid-wall and/or subendocardial enhancement after Gd-BOPTA was associated with viable myocardium, whereas detection of microvascular obstruction correlating with scar formation is suggested by mid-wall hypoenhancement within the first five minutes after injection.

[31P-MR spectroscopy of all regions of the human heart at 1.5 T with acquisition-weighted chemical shift imaging]

AIM

Aim of this study was to show whether or not acquisition-weighted chemical shift imaging (AW-CSI) allows the determination of PCr and ATP in the lateral and posterior wall of the human heart at 1.5 T.

METHODS

12 healthy volunteers were examined using a conventional chemical shift imaging (CSI) and an AW-CSI. The sequences differed only in the number of repetitions for each point in k space. A hanning function was used as filter function leading to 7 repetitions in the center of the k space and 0 in the corners. Thus, AW-CSI had the same resolution as the CSI sequence. The results for both sequences were analyzed using identically positioned voxels in the septal, anterior, lateral and posterior wall.

RESULTS

The determined averaged AW-CSI signal to noise ratios were higher for PCr by a factor of 1.3 and for ATP by 1.4 than those of CSI. The PCr/ATP ratios were higher by a factor of 1.2 - 1.3 and showed a smaller standard deviation in all locations for AW-CSI. The mean PCr/ATP ratios determined by AW-CSI of septal, lateral and posterior wall were almost identical (1.72 - 1.76), while it was higher in the anterior wall (1.9).

CONCLUSIONS

The reduced contamination in AW-CSI improves the signal to noise ratio and the determination of the PCr/ATP ratio in cardiac (31)P spectroscopy compared to CSI with the same resolution. The results in volunteers indicate that AW-CSI renders (31)P spectroscopy of the lateral and posterior wall of the human heart feasible for patient studies at 1.5 T.

MR angiography of the hand arteries

The aim of this study was to optimize different magnetic resonance angiography (MRA) techniques and to evaluate MRA of the hand arteries compared to intraarterial digital subtraction angiography (IA-DSA). The MRA examinations were performed on a 1.5-T system equipped with a flexible surface coil. The protocol contained time-of-flight (TOF), rephased/dephased (Re/De), and contrast enhanced (CE) techniques. Maximum intensity projection (MIP) was used for postprocessing. The IA-DSA procedure was performed as pharmaco-angiography (after intraarterial injection of a vasodilatator) via a transbrachial approach. Nine patients suffering from peripheral vascular disease were examined with IA-DSA, TOF-MRA, and Re/De-MRA; six patients were examined with CE-MRA and IA-DSA. Best overall image quality was attained with IA-DSA, followed by TOF-MRA, Re/De-MRA, and CE-MRA. Selective arterial visualization of digital arteries was possible with IA-DSA and TOF-MRA. Rephased/dephased MRA showed venous overlay. Contrast-enhanced MRA was limited by inconstant quality of bolus timing. Appropriate arterial bolus timing was achieved in four of six patients; one examination showed venous overlay, one examination incomplete arterial enhancement. Time-of-flight MRA detected 96% of the digital artery segments that were identified with IA-DSA and revealed 34 segments that were failed on IA-DSA. Rephased/dephased MRA and CE-MRA were inferior to IA-DSA and TOF-MRA regarding detection of digital arteries. Magnetic resonance angiography with optimized protocols is a noninvasive procedure to visualize hand arteries in patients with ischemic disease. With TOF-MRA it is possible to detect angiographically occluded arterial segments of digital arteries.

Assessment of myocardial infarction in humans with (23)Na MR imaging: comparison with cine MR imaging and delayed contrast enhancement

PURPOSE

To demonstrate the feasibility of sodium 23 ((23)Na) magnetic resonance (MR) imaging for assessment of subacute and chronic myocardial infarction and compare with cine, late enhancement, and T2-weighted imaging.

MATERIALS AND METHODS

Thirty patients underwent MR imaging 8 days +/- 4 (subacute, n = 15) or more than 6 months (chronic, n = 15) after myocardial infarction by using a (23)Na surface coil with a double angulated electrocardiogram-triggered three-dimensional gradient-echo sequence at 1.5 T. In addition, cine, inversion-recovery gradient-echo, and, in the subacute group, T2-weighted images (n = 9) were obtained. Myocardial infarction mass was depicted as elevated signal intensity or wall motion abnormalities and expressed as a percentage of total left ventricular mass for all modalities. Correlations were tested with correlation coefficients.

RESULTS

All patients after subacute infarction and 12 of 15 patients with chronic infarction had an area of elevated (23)Na signal intensity that significantly correlated with wall motion abnormalities (subacute; r = 0.96, P <.001, and chronic; r = 0.9, P <.001); three patients had no wall motion abnormalities or elevated (23)Na signal intensity. Only 10 patients in the subacute and nine in the chronic group revealed late enhancement; significant correlation with (23)Na MR imaging occurred only in subacute group (r = 0.68, P <.05). Myocardial edema in subacute infarction correlated (r = 0.71, P <.05) with areas of elevated (23)Na signal intensity but was extensively larger.

CONCLUSION

(23)Na MR imaging demonstrates dysfunctional myocardium caused by subacute and chronic myocardial infarction.

(31)P-MR Spectroscopy for the evaluation of energy metabolism in intact residual myocardium after acute myocardial infarction in humans

OBJECTIVE

Experimental studies have demonstrated that acute myocardial infarction (MI) alters energy metabolism even in non-infarcted adjacent tissue. In patients with subacute MI, the influence of the regional ischemic insult on energy metabolism of intact septal myocardium was analyzed using 31P-Magnetic resonance spectroscopy (MRS).

PATIENTS AND METHODS

In eight patients with wall motion abnormalities in the anterior wall 31P-spectra were obtained from non-infarcted adjacent septal myocardium, as well as infarcted anterior myocardium (voxel size 25 ccm each) 29+/-8 days after MI using a 3D-CSI technique. Additionally, cardiac function was analyzed using breath-hold cine MRI. MRI was repeated 6 months after revascularization to assess viability of infarcted segments. Eight age-matched healthy volunteers served as control group.

RESULTS

According to follow-up MRI 4/8 patients showed regional wall motion recovery. Here, PCr/ATP-ratios were not significantly reduced in intact septal myocardium as well as infarcted anterior myocardium compared to healthy volunteers (1.28+/-0.10 and 1.14+/-0.09 vs. 1.45+/-0.29). No recovery of regional function was detected in 4/8 patients with-therefore-non-viable anterior myocardium. PCr/ATP-ratios were significantly reduced in intact and infarcted myocardium compared with healthy volunteers as well as to patients with wall motion recovery (0.77+/-0.17 and 0.49+/-0.23; P<0.05).

DISCUSSION

These preliminary results indicate that energy metabolism is reduced in patients with persisting wall motion abnormalities after myocardial infarction and revascularization in ischemically injured as well as in adjacent non-injured myocardium.

Dichotomy of AML1-ETO functions: growth arrest versus block of differentiation

The fusion gene AML1-ETO is the product of t(8;21)(q22;q22), one of the most common chromosomal translocations associated with acute myeloid leukemia. To investigate the impact of AML1-ETO on hematopoiesis, tetracycline-inducible AML1-ETO-expressing cell lines were generated using myeloid cells. AML1-ETO is tightly and strongly induced upon tetracycline withdrawal. The proliferation of AML1-ETO(+) cells was markedly reduced, and most of the cells eventually underwent apoptosis. RNase protection assays revealed that the amount of Bcl-2 mRNA was decreased after AML1-ETO induction. Enforced expression of Bcl-2 was able to significantly delay, but not completely overcome, AML1-ETO-induced apoptosis. Prior to the onset of apoptosis, we also studied the ability of AML1-ETO to modulate differentiation. AML1-ETO expression altered granulocytic differentiation of U937T-A/E cells. More significantly, this change of differentiation was associated with the down-regulation of CCAAT/enhancer binding protein alpha (C/EBPalpha), a key regulator of granulocytic differentiation. These observations suggest a dichotomy in the functions of AML1-ETO: (i) reduction of granulocytic differentiation correlated with decreased expression of C/EBPalpha and (ii) growth arrest leading to apoptosis with decreased expression of CDK4, c-myc, and Bcl-2. We predict that the preleukemic AML1-ETO(+) cells must overcome AML1-ETO-induced growth arrest and apoptosis prior to fulfilling their leukemogenic potential.

Cardiac metabolism and function in patients with multiple sclerosis: a combined 31P-MR-spectroscopy and MRI study

OBJECTIVE

Involvement of the autonomic system in multiple sclerosis (MS) may concur with dysfunction of the cardiovascular system. The introduction of potentially cardiotoxic immunosuppressive drugs like Mitoxantrone into the treatment of MS warrants proper assessment of preexisting heart disease. However, systematic analyses of functional and metabolic derangements in MS are missing. Using quantitative 31P-MR-spectroscopy (MRS) and MR-imaging (MRI) metabolic and functional parameters were analyzed in patients with MS in comparison to healthy volunteers.

SUBJECTS/METHODS

14/15 patients with MS could be included in the study, as the MRS examination of one patient had to be excluded from analysis due to movement during the examination. Using chemical shift imaging (CSI) and AMARES, phosphocreatine (PCr) to adenosine triphosphate (ATP) ratios, characterizing myocardial high-energy phosphate metabolism, were determined. Additionally, absolute concentrations of PCr and ATP were calculated by SLOOP (Spatial Localization with Optimal Pointspread Function). Analysis of functional changes was performed by Cine-MRI. 14 healthy volunteers matched for age and gender served as control.

RESULTS

A significant decrease of absolute PCr concentration was observed in patients with MS compared to matched volunteers (p < 0.05), whereas ATP concentrations showed no significant changes (p = 0.27). Metabolite ratios calculated by SLOOP or AMARES showed a tendency to be reduced in patients, however, did not reach significance (p = 0.08, SLOOP; p = 0.47, AMARES). Using volunteers' mean values +/- 2 x SD as cut off value revealed PCr changes in 5 of 14 patients, whereas only 2 also had pathologic PCr/ATP ratios. Functional analysis by MRI depicted depressed left ventricular ejection fraction in 4 patients.

CONCLUSIONS

The reduction in cardiac high-energy phosphates in some patients with MS points to a subclinical involvement of the heart. This may be important for treatment with potentially cardiotoxic drugs. Longitudinal studies are need to understand the clinical relevance of our findings.

Understanding why contrast enhancement in dynamic MRI is not reproducible: illustration with a simple phantom

The goal of this work was to verify in a phantom study the necessity of a calibration method for comparison in dynamic contrast-enhanced magnetic resonance imaging (MRI) examinations. A perspex phantom with a dilution series of Gd-DTPA was used to measure the dynamic signal enhancement of a sequence. With nine MRI scanners from Bruker (0.23, 0.5, and 2 Tesla), Philips [0.5 and 1.5 Tesla (ACS-NT and S15)], and Siemens (0.2, 1.0, and 1.5 Tesla) one 2D FLASH and two 3D FLASH experiments were performed under identical measurement conditions. Under different measurement conditions (2D and 3D FLASH, TR, TE, FA) different characteristics in signal enhancement exist on a scanner. The same measurement conditions at different scanners (same magnetic field strength) also result in different signal enhancement. Dynamic contrast enhanced MRI examinations from different measurement conditions or scanners cannot be compared. To solve this problem a calibration is needed.