[West-Nile-Virus Infection acquired in Germany in a Kidney Transplant Recipient]

BACKGROUND

West-Nile-Virus (WNV) is a widely distributed flavivirus that is mainly transmitted between birds through different mosquito species (e. g. Culex, Aedes), but may also be transmitted to mammals including humans. WNV causes a spectrum of disease, ranging from asymptomatic infection to encephalitis in a minority of cases. Risk factors for severe disease are older age, cardiovascular disease and an immunocompromised state.

MEDICAL HISTORY AND CLINICAL EXAMINATION

Here we report about a 60-year-old male patient who was referred to the University Hospital of Halle (Saale) with severe fever two years after kidney transplantation due to hypertensive nephropathy. No infection focus could be found and by day 6 in the course of his illness the patient developed neurologic symptoms and viral encephalitis was suspected.

TREATMENT AND COURSE

The patient was initially treated with aciclovir. After initial reduction of immunosuppression, coincident graft dysfunction was treated with methylprednisolon. WNV-infection was suspected due to recent emerging human cases in the nearby area of the city of Leipzig. WNV lineage 2 was detected in the patient's urine by RT-PCR and seroconversion with presence of anti WNV IgM and IgG could be demonstrated. Consecutively, aciclovir treatment was stopped. The patient fully recovered and the transplanted kidney regained adequate function. Kidney biopsy did not reveal gross rejection of the transplant.

CONCLUSION

This case highlights the need to consider rarer causes of illness like WNV-infection particularly in risk groups for more severe outcomes of infectious disease. WNV may be detected by PCR in the blood and cerebrospinal fluid early in the course of infection but it is also excreted for a prolonged period of time in the urine. Seroconversion to anti WNV IgG and IgM may be shown but serologic cross-reactivity among members of the flaviviridae family must be considered.

Prospective evaluation study on the benefit of the simultaneous detection of seven sexually transmitted pathogens for the clinical management of patients suffering from sexually transmitted diseases

Background

Sexually transmitted infections (STIs) represent a growing relevant public health problem. Early and accurate STI diagnosis is capable of preventing the spread and severe complications of curable STIs through pathogen adapted antibiotic treatment regimens. Limitations of current STI diagnostic tools are the lack of simultaneous pathogen detection and result quantification.

Methods

A prospective analysis of clinical specimens (n=100, from 82 symptomatic patients) from different sites of infections was performed. All samples were processed with multiplex real-time polymerase chain reaction (PCR) assay Anyplex™ II STI-7, using thermal cycler CFX96™. The Anyplex™ II STI-7 detection assay covers Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), Mycoplasma hominis (MH), Ureaplasma parvum (UP), Ureaplasma urealyticum (UU) and Trichomonas vaginalis (TV). STI-7 results were compared to standard methods and transferred to the attending physician for treatment adjustment.

Results

Compared to performed standard method results the assay achieved sensitivities ranging from 90.9% to 100%, respectively, and specificities of 100%, with negative predictive values (NPV) ranging from 98.5% to 100%, respectively, and positive predictive values (PPV) of 100%. The Anyplex™ II STI-7 detection assay measured a Cohen’s kappa of 1.00 for UU/UP, MH, and MG and a Cohen’s κ agreement of 0.95 and 0.96 for NG and CT, respectively.

Conclusions

The Anyplex™ II STI-7 assay can easily be introduced into the microbiological laboratory work flow due to its short hands-on-time and PCR mutiplexity. The simultaneous detection of seven STI pathogens provides a comprehensive profile for each patient, enabling clinicians to decide on best treatment options, decreasing antibiotic misuse and infection spreading risk. The semi-quantitative results enables clinicians to gain a complete package of diagnostic information including disease diagnosis, disease degree severity and treatment monitoring, although. Further clinical studies on this topic are needed.

EBV miRNA expression profiles in different infection stages: A prospective cohort study

The Epstein-Barr virus (EBV) produces different microRNAs (miRNA) with distinct regulatory functions within the infectious cycle. These viral miRNAs regulate the expression of viral and host genes and have been discussed as potential diagnostic markers or even therapeutic targets, provided that the expression profile can be unambiguously correlated to a specific stage of infection or a specific EBV-induced disorder. In this context, miRNA profiling becomes more important since the roles of these miRNAs in the pathogenesis of infections and malignancies are not fully understood. Studies of EBV miRNA expression profiles are sparse and have mainly focused on associated malignancies. This study is the first to examine the miRNA profiles of EBV reactivation and to use a correction step with seronegative patients as a reference. Between 2012 and 2017, we examined the expression profiles of 11 selected EBV miRNAs in 129 whole blood samples from primary infection, reactivation, healthy carriers and EBV seronegative patients. Three of the miRNAs could not be detected in any sample. Other miRNAs showed significantly higher expression levels and prevalence during primary infection than in other stages; miR-BHRF1-1 was the most abundant. The expression profiles from reactivation differed slightly but not significantly from those of healthy carriers, but a specific marker miRNA for each stage could not be identified within the selected EBV miRNA targets.

Value of the eazyplex® CSF direct assay in rapid diagnosis of invasive meningococcal disease - Case report

There is a need for easy-to-use molecular assays for diagnosis of invasive meningococcal disease. Here, we report the rapid identification of Neisseria meningitidis in a cerebrospinal fluid sample from a patient with purulent meningitis using a commercially available loop-mediated isothermal amplification assay, resulting in a prompt de-escalation of the initial empiric antibiotic therapy.

Neuroborreliosis and acute encephalopathy: The use of CXCL13 as a biomarker in CNS manifestations of Lyme borreliosis

We report the case of an 80-year-old patient with acute onset confusion initially suspected to reflect delirium in incipient Alzheimer's disease. Cerebrospinal fluid tests revealed an unusually severe form of neuroborreliosis, which resolved following antibiotic treatment. This was mirrored in the measurement of CXCL13, which is suggested as a complementary biomarker. Clinical implications for screening, differential diagnosis and treatment are discussed.

Evaluation of loop-mediated isothermal amplification for the rapid identification of bacteria and resistance determinants in positive blood cultures

The use of molecular assays to rapidly identify pathogens and resistance genes directly from positive blood cultures (BCs) contribute to shortening the time required for the diagnosis of bloodstream infections. In this work, loop-mediated isothermal amplification (LAMP) assays have been examined for their potential use in BC diagnosis. Three different assays were applied. The commercially available eazyplex® MRSA test detects Staphylococcus aureus, S. epidermidis, mecA, and mecC. Two in-house assays [Gram-positive (GP) and Gram-negative (GN)] have been developed for the detection of streptococci, enterococci, vanA, vanB, Pseudomonas spp., Enterobacteriaceae, and the bla _CTX-M family. A total of 370 positive BCs were analyzed. LAMP test results were obtained within 30 min, including sample preparation. Amplification was measured by real-time fluorescence detection. The threshold time for fluorescence intensity values ranged from 6.25 to 13.75 min. The specificity and sensitivity of the assays varied depending on the target. Overall, from 87.7% of BCs, true-positive results were obtained, compared to routine standard diagnosis. Twenty-one tests were true-negative because of the lack of an appropriate target (5.7%). The concordance of positive test results for resistance genes with subsequent antibiotic susceptibility testing was 100%. From 15 BC bottles with mixed cultures, eazyplex® assays produced correct results in 73% of the cases. This study shows that LAMP assays are fast and cost-saving tools for rapid BC testing in order to expedite the diagnostic report and improve the antibiotic stewardship for sepsis patients.

Eight Cycles of ABVD Versus Four Cycles of BEACOPPescalated Plus Four Cycles of BEACOPPbaseline in Stage III to IV, International Prognostic Score ≥ 3, High-Risk Hodgkin Lymphoma: First Results of the Phase III EORTC 20012 Intergroup Trial

PURPOSE

To compare patients with high-risk stage III to IV Hodgkin lymphoma (HL) in the phase III European Organisation for Research and Treatment of Cancer 20012 Intergroup trial (Comparison of Two Combination Chemotherapy Regimens in Treating Patients With Stage III or Stage IV Hodgkin's Lymphoma) who were randomly assigned to either doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) or to bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP).

PATIENTS AND METHODS

Patients with clinical stage III or IV HL, International Prognostic Score of 3 or higher, and age 60 years or younger received ABVD for eight cycles (ABVD8) or escalated-dose BEACOPP (BEACOPPescalated) for four cycles followed by baseline BEACOPP (BEACOPPbaseline) for four cycles (BEACOPP4+4) without radiotherapy. Primary end points were event-free survival (EFS), treatment discontinuation, no complete response (CR) or unconfirmed complete response (CRu) after eight cycles, progression, relapse, or death. Secondary end points were CR rate, overall survival (OS), quality of life, secondary malignancies, and disease-free survival in CR/CRu patients.

RESULTS

Between 2002 and 2010, 549 patients were randomly assigned to ABVD8 (n = 275) or BEACOPP4+4 (n = 274). Other characteristics included median age, 35 years; male, 75%; stage IV, 74%; "B" symptoms, 81%; and International Prognostic Score ≥ 4, 59%. WHO performance status was 0 (34%), 1 (48%), or 2 (17%). Median follow-up was 3.6 years. CR/CRu was 82.5% in both arms. At 4 years, EFS was 63.7% for ABVD8 versus 69.3% for BEACOPP4+4 (hazard ratio [HR], 0.86; 95% CI, 0.64 to 1.15; P = .312); disease-free survival was 85.8% versus 91.0% (HR, 0.59; 95% CI, 0.33 to 1.06; P = .076), and OS was 86.7% versus 90.3% (HR, 0.71; 95% CI, 0.42 to 1.21; P = .208). Death as a result of toxicity occurred in six and five patients, early discontinuation (before cycle 5) in 12 and 26 patients, treatment crossovers in five and 10 patients, and secondary malignancies in eight and 10 patients in the ABVD8 and BEACOPP4+4 arms, respectively.

CONCLUSION

ABVD8 and BEACOPP4+4 resulted in similar EFS and OS in patients with high-risk advanced-stage HL. Because BEACOPP4+4 did not demonstrate a favorable effectiveness or toxicity ratio compared with ABVD8, treatment burden, immediate and late toxicities, and associated costs must be considered before selecting one of these regimens on which to build future treatment strategies.

Antibiotic treatment algorithm development based on a microarray nucleic acid assay for rapid bacterial identification and resistance determination from positive blood cultures

Rapid diagnosis of bloodstream infections remains a challenge for the early targeting of an antibiotic therapy in sepsis patients. In recent studies, the reliability of the Nanosphere Verigene Gram-positive and Gram-negative blood culture (BC-GP and BC-GN) assays for the rapid identification of bacteria and resistance genes directly from positive BCs has been demonstrated. In this work, we have developed a model to define treatment recommendations by combining Verigene test results with knowledge on local antibiotic resistance patterns of bacterial pathogens. The data of 275 positive BCs were analyzed. Two hundred sixty-three isolates (95.6%) were included in the Verigene assay panels, and 257 isolates (93.5%) were correctly identified. The agreement of the detection of resistance genes with subsequent phenotypic susceptibility testing was 100%. The hospital antibiogram was used to develop a treatment algorithm on the basis of Verigene results that may contribute to a faster patient management.

Database on natural polymorphisms and resistance-related non-synonymous mutations in thymidine kinase and DNA polymerase genes of herpes simplex virus types 1 and 2

The use of genotypic resistance testing of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) is increasing because the rapid availability of results significantly improves the treatment of severe infections, especially in immunocompromised patients. However, an essential precondition is a broad knowledge of natural polymorphisms and resistance-associated mutations in the thymidine kinase (TK) and DNA polymerase (pol) genes, of which the DNA polymerase (Pol) enzyme is targeted by the highly effective antiviral drugs in clinical use. Thus, this review presents a database of all non-synonymous mutations of TK and DNA pol genes of HSV-1 and HSV-2 whose association with resistance or natural gene polymorphism has been clarified by phenotypic and/or functional assays. In addition, the laboratory methods for verifying natural polymorphisms or resistance mutations are summarized. This database can help considerably to facilitate the interpretation of genotypic resistance findings in clinical HSV-1 and HSV-2 strains.

Education-corrected CERAD identifies MCI and dementia in Parkinson's disease

OBJECTIVES

This study examined whether controlling for educational background in the CERAD cognitive screening battery would affect the likelihood of patients with Parkinson's disease to fulfill criteria for mild cognitive impairment (PD-MCI) and dementia (PDD).

MATERIALS & METHODS

One-hundred seventeen patients with PD were studied. Cognitive impairment was determined as two subtest scores falling below either the standard cutoff scores or education-corrected cutoff scores. The presence of dementia was determined by clinical interview or Clinical Dementia Rating. Patients were then classified as PD-MCI and PDD according to cognitive test performance and presence/absence of dementia.

RESULTS

The number of cognitively impaired patients (PD-MCI or PDD) was significantly higher when education-controlled cutoff scores were used (62.5% vs 38%). Correspondingly, the number of false negatives (demented PD patients performing normally in CERAD) was significantly lower when education-corrected cutoff scores were used (4% vs 10%).

CONCLUSIONS

Controlling for education increases the sensitivity of the CERAD for PD-MCI and PDD.

Fighting fire with fire: a patent for the combined application of oncolytic herpes viruses and antiangiogenic agents in the battle against human cancers

Specific elimination of tumor cells by replication-competent viral vectors is mediated through active viral replication, spread in tumor tissue and direct cytopathic effects. In addition, immune responses are induced against virally infected tumor cells. Recently, oncolytic vectors were constructed with mutations in neurovirulence genes or DNA synthesis genes. Viral replication should only be restricted to malignant cells to prevent severe viral disease. These constructed vectors terminate cells by mechanisms different from standard anti-cancer therapies; they offer another treatment modality which can be used in combination with chemotherapy, radiotherapy and gene therapies with additive or synergistic effects. Combination therapies are usually necessary to control tumorigenic diseases. Inhibiting angiogenesis represents another new field in current anticancer treatment development. Combining an oncolytic virus with antiangiogenesis is able to potentiate both treatment effects compared to each treatment modality alone in both primary and advanced disease. This combination might be beneficial for cancer patients in the future. We have also outlined some relevant patents.

Detection of pneumonia associated pathogens using a prototype multiplexed pneumonia test in hospitalized patients with severe pneumonia

Severe pneumonia remains an important cause of morbidity and mortality. Polymerase chain reaction (PCR) has been shown to be more sensitive than current standard microbiological methods – particularly in patients with prior antibiotic treatment – and therefore, may improve the accuracy of microbiological diagnosis for hospitalized patients with pneumonia. Conventional detection techniques and multiplex PCR for 14 typical bacterial pneumonia-associated pathogens were performed on respiratory samples collected from adult hospitalized patients enrolled in a prospective multi-center study. Patients were enrolled from March until September 2012. A total of 739 fresh, native samples were eligible for analysis, of which 75 were sputa, 421 aspirates, and 234 bronchial lavages. 276 pathogens were detected by microbiology for which a valid PCR result was generated (positive or negative detection result by Curetis prototype system). Among these, 120 were identified by the prototype assay, 50 pathogens were not detected. Overall performance of the prototype for pathogen identification was 70.6% sensitivity (95% confidence interval (CI) lower bound: 63.3%, upper bound: 76.9%) and 95.2% specificity (95% CI lower bound: 94.6%, upper bound: 95.7%). Based on the study results, device cut-off settings were adjusted for future series production. The overall performance with the settings of the CE series production devices was 78.7% sensitivity (95% CI lower bound: 72.1%) and 96.6% specificity (95% CI lower bound: 96.1%). Time to result was 5.2 hours (median) for the prototype test and 43.5 h for standard-of-care. The Pneumonia Application provides a rapid and moderately sensitive assay for the detection of pneumonia-causing pathogens with minimal hands-on time.

Trial Registration

Deutsches Register Klinischer Studien (DRKS) DRKS00005684

Apathy is associated with activities of daily living ability in Parkinson's disease

BACKGROUND

Neuropsychiatric symptoms and impairment in performing activities of daily living (ADL) in patients with Parkinson's disease (PD) are strong predictors of the overall caregiver burden and they increase the risk for nursing home admission of the patients. The purpose of the present study was to assess the association of neuropsychiatric symptoms and ADL functions in PD.

METHODS

A total of 73 community-dwelling PD patients were studied. The mean age of the patient group was 65 years and the mean disease duration was 9 years. The Neuropsychiatric Inventory was used to measure neuropsychiatric symptoms, and ADL abilities were measured by the Alzheimer's Disease Cooperative Study-Activities of Daily Living Inventory.

RESULTS

The prevalence of neuropsychiatric symptoms in patients with PD was 73%. The most common symptoms were depression, anxiety, irritability, apathy and agitation. ADL ability correlated significantly with apathy (p < 0.002) even when adjusted for motor symptoms.

CONCLUSION

Apathy was significantly associated with ADL in PD. The result indicates that more attention should be paid to identifying apathy and targeting therapeutic interventions.

Sequential Combination of Gemtuzumab Ozogamicin and Standard Chemotherapy in Older Patients With Newly Diagnosed Acute Myeloid Leukemia: Results of a Randomized Phase III Trial by the EORTC and GIMEMA Consortium (AML-17)

Purpose

This randomized trial evaluated the efficacy and toxicity of sequential gemtuzumab ozogamicin (GO) and standard chemotherapy in older patients with newly diagnosed acute myeloid leukemia (AML).

Patients and Methods

Patients (n = 472) age 61 to 75 years were randomly assigned to induction chemotherapy with mitoxantrone, cytarabine, and etoposide preceded, or not, by a course of GO (6 mg/m2 on days 1 and 15). In remission, patients received two consolidation courses with or without GO (3 mg/m2 on day 0). The primary end point was overall survival (OS).

Results

The overall response rate was comparable between the two arms (GO, 45%; no GO, 49%), but induction and 60-day mortality rates were higher in the GO arm (17% v 12% and 22% v 18%, respectively). With median follow-up of 5.2 years, median OS was 7.1 months in the GO arm and 10 months in the no-GO arm (hazard ratio, 1.20; 95% CI, 0.99 to 1.45; P = .07). Other survival end points were similar in both arms. Grade 3 to 4 hematologic and liver toxicities were greater in the GO arm. Treatment with GO provided no benefit in any prognostic subgroup, with the possible exception of patients age < 70 years with secondary AML, but outcomes were significantly worse in the oldest age subgroup because of a higher risk of early mortality.

Conclusion

As used in this trial, the sequential combination of GO and standard chemotherapy provides no benefit for older patients with AML and is too toxic for those age ≥ 70 years.

CERAD test performance and cognitive impairment in Parkinson's disease

OBJECTIVES

Many patients with Parkinson's disease (PD) develop mild cognitive impairment (PD-MCI) and dementia (PDD). The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neurocognitive test battery was originally developed to identify early Alzheimer's disease, but it has become a widely used screening instrument also for other types of dementia. The aim of the study was to examine differences in CERAD test performances between cognitively intact and impaired PD patients.

MATERIALS AND METHODS

Eighty-eight PD patients participating in a rehabilitation course were studied. The Clinical Dementia Rating (CDR) was used to assess cognitive impairment. Sixty-six patients were cognitively intact and 22 had cognitive impairment (≥1 in two or more domains or a sum of boxes score of ≥3). The Finnish CERAD test battery was used to measure cognitive functions in seven different domains (language functions, verbal learning, visuospatial functions, delayed recall, memory consolidation, recognition memory, and executive functions).

RESULTS

There were significant differences between the cognitively intact and impaired patients in six CERAD subtests (wordlist learning sum, wordlist delayed recall, constructional praxis recall, clock drawing, verbal fluency and constructional praxis copy) when controlling for covariates (disease duration, motor symptoms, age, and education). No differences were observed in memory consolidation scores.

CONCLUSIONS

The results indicate that mild cognitive impairment in PD is related to deficits in memory, executive functions, and visuospatial functions. The memory deficit is non-amnestic and does not entail accelerated forgetting. CERAD shows promise in identifying PD patients with cognitive impairment and increased risk of dementia.

Five-year follow-up of 11C-PIB uptake in Alzheimer's disease and MCI

PURPOSE

The aim of this study was to evaluate the longitudinal changes in [(11)C]PIB uptake in mild cognitive impairment (MCI) and Alzheimer's disease (AD) over a long-term follow-up.

METHODS

Six AD patients, ten MCI patients and eight healthy subjects underwent a [(11)C]PIB PET scan at baseline and at 2 and 5 years. The clinical status of the MCI patients was evaluated every 6 months.

RESULTS

The MCI group showed a significant increase in [(11)C]PIB uptake over time (p < 0.001), with a similar increase from baseline to 2 years (4.7% per year) and from 2 to 5 years (5.0% per year). Eight MCI patients (80%) converted to AD, and two of these patients showed a normal [(11)C]PIB scan at baseline but increased uptake later. There was an increase in [(11)C]PIB uptake with time in the AD group (p = 0.02), but this did not significantly differ from the change in the control group.

CONCLUSION

Our results revealed a significant increase in amyloid load even at the time of AD diagnosis in some of the MCI patients who converted. A positive [(11)C]PIB scan at baseline in MCI patients strongly predicted future conversion to AD but a negative PIB scan in MCI patients did not exclude future conversion. The results suggest that there is wide individual variation in the brain amyloid load in MCI, and in the course of amyloid accumulation in relation to the clinical diagnosis of AD.

A new molecular diagnostic tool for pneumocystis jirovecii-pneumonia (PjP) detection: Results from European multicenter clinical study CS-2011

e20652

Background: Pneumocystis pneumonia (PCP) is a frequent and serious infectious complication in tumor patients. PCP is caused by Pneumocystis jirovecii, a fungal pathogen which is uncultivable in vitro. Highly-sensitive and time-efficient diagnostic tools are needed for early PCP treatment, especially in patients with impaired immune status. Methods: We evaluated a prototype of a new non-invasive molecular diagnostic tool (Unyvero System) using polymerase chain reaction (PCR) for P. jirovecii detection in respiratory samples (bronchoalveolar lavage fluid, tracheal aspirates, sputum) of hospitalized patients suffering from pneumonia. Results were obtained in an open-label, multicentric, non-randomized clinical study (CS-2011) conducted in 5 European hospitals. Unyvero system test results were compared to study site specific PCR results for P. jirovecii detection. Discrepant results were analysed for clinical relevance of molecular diagnostic tool results. Results: P. jirovecii was detected in 11 patients (1.49 %) out of 739 evaluable study patients: Of these, 8 cases (1.08 %) were detected only with the Unyvero System, 2 cases only with site-established techniques and 1 case with both methods. An independent academic cross-check of these 8 Unyvero System -positive cases showed that 5 cases were false positives due to signal reading failure. The remaining 3 cases could be confirmed as true positives by control PCP-PCR, indicating Unyvero P. jiroveciidetection results of 2 false negatives, 4 true positives and 5 false positives. Conclusions: The overall detection rate for P. jirovecii was low (11 out of 739) in this study population. Although more positive cases were found using the Unyvero System, it remains unclear if this was of clinical significance, especially as two clinically confirmed PCP cases could not be detected. The Unyvero System prototypes had a rate of 0.7% false positive results (5 out of 739 samples) which might have led to an overtreatment under real conditions. However, the correct detection of 4 positive cases within 3 hours might render the Unyvero System a valuable diagnostic future tool.

Prospective International Multicenter Phase II Trial of Intravenous Pegylated Liposomal Doxorubicin Monochemotherapy in Patients With Stage IIB, IVA, or IVB Advanced Mycosis Fungoides: Final Results From EORTC 21012

Purpose

Mycosis fungoides (MF) is the most common primary cutaneous T-cell lymphoma. There is a need for multicenter trials involving defined patient populations using rigorous assessment criteria. We have investigated pegylated liposomal doxorubicin (PLD) in a clearly defined patient population with advanced MF.

Patients and Methods

Eligible patients had stage IIB, IVA, or IVB MF, refractory or recurrent after at least two previous systemic therapies. Patients were registered to receive a maximum of six cycles of PLD 20 mg/m2on days 1 and 15, every 28 days (one cycle). The primary end point was response rate (RR).

Results

Nine centers recruited 49 eligible patients. The median number of chemotherapy cycles received was five. There were no grade 3 to 4 hematologic toxicities. Grade 3 or 4 nonhematologic/nonbiochemical toxicities included cardiac symptom (2%), allergy/hypersensitivity (2%), constitutional symptom (4%), hand and foot reaction (2%), other dermatologic toxicity (6%), other GI toxicity (4%), infection (4%), pulmonary embolism (2%), and cardiac ischemia (2%). Of 49 patients, 20 (40.8%) were responders (complete clinical response [CCR] or partial response [PR] as overall response): three (6.1%) experienced CCRs, and 17 (34.7%) experienced PRs. A 50% or greater reduction of cutaneous manifestations was observed in 26 (60.5%) of 43 assessable patients. Two early deaths were reported, resulting from related cardiovascular toxicity and disease progression. The lower limit of the one-sided 90% CI for RR was 31.2%. Median time to progression and median duration of response were 7.4 and 6 months, respectively.

Conclusion

PLD has an acceptable safety profile in patients with advanced MF. The efficacy of PLD seems promising.

A systemic review of toxic death in clinical oncology trials: an Achilles' heel in safety reporting revisited

BACKGROUND

Toxic death is defined as study treatment-related mortality and as such is considered as an iatrogenic death. This belongs to unnatural death where an autopsy is advised. Until now, conventional autopsy is the gold standard to discriminate between pre- and post-mortem discrepancies.

METHODS

The consequences of lack of systematically performing an autopsy will be explored in the setting of oncological clinical trials.

RESULTS

During more than one decade, 6428 Serious Adverse Events have been registered in the EORTC Safety database on a total of 34 734 subjects. The number of deaths were 764 (mortality rate of 2.2%) whereof 255 (rate of 0.7%) toxic deaths. In 89.8% of these toxic deaths, no autopsy has been done; in 25.1% (64 cases) an inconsistent cause of death was found based on studying of the medical narrative. The autopsy rate was only 10.2% (26 out of 255) and, in 46.2% of the performed autopsies, there was a clinical pathological discrepancy.

CONCLUSION

When no autopsy is performed, there is a high risk for a wrong diagnosis in case of suspected toxic death. The high discrepancy rate, possibly due to a low autopsy rate, shows that toxic death is an Achilles' heel in iatrogenic mortality.

ABVD (8 cycles) versus BEACOPP (4 escalated cycles => 4 baseline) in stage III-IV high-risk Hodgkin lymphoma (HL): First results of EORTC 20012 Intergroup randomized phase III clinical trial

8002

Background: Escalated BEACOPP and derivatives achieved superior time to treatment failure (FFTF) over COPP/ABVD, resulting in higher overall survival (OS) for advanced HL. However, later clinical trials have failed to confirm OS superiority over ABVD. Methods: Eligibility criteria: clinical stage III/IV HL, International prognostic score (IPS) ≥ 3, age<60. We compared ABVD (8 cycles) vs. BEACOPP (escalated 4 cycles ≥ baseline 4), without irradiation. Randomization was stratified for institution and IPS. Primary endpoint was EFS, defined as treatment discontinuation, no complete response (CR) after 8 cycles, progression, relapse or death. Additional endpoints were CR, progression free survival (PFS), OS, quality of life and secondary malignancies. Outcomes were reviewed by study coordinators to ensure consistency across pts. Results: From 2002-2010, 549 pts were randomized (ABVD 275, BEACOPP 274): stage IV 74%, PS 0, 1, 2: 34, 48 and 17%, B-symptoms 81%, median age 35.2y, males 75%. IPS was 4 or higher for 59% of pts. Histology reviewed no HL in 4 cases. CR was 83% in both arms. With a median follow-up of 3.8 yrs, EFS at 4 yrs was 63.7% vs. 69.3% (HR = 0.86, 95%CI=0.64 to 1.15, p=0.312). PFS at 4 yrs was 72.8% vs. 83.4% (HR = 0.58, 95%CI=0.39 to 0.85, p=0.005). OS at 4 yrs was 86.7 vs. 90.3 (HR = 0.71, 95%CI=0.42 to 1.21, p=0.208). Toxic deaths occurred in 6 and 5 pts, with early discontinuation (prior to cycle 5) in 12 & 26 pts, respectively. There were 5 crossovers to BEACOPP and 10 to ABVD. Second malignancies occurred in 8 ABVD and 10 BEACOPP pts (myelodysplasia/leukemia 2 and 4, lung 2 and 1, NHL 3 and 2, other 1 and 3); cumulative incidence curves did not differ significantly. Conclusions: The primary endpoint (EFS) was similar between treatment arms. However, more progressions/relapses were observed with ABVD, while early discontinuations were more frequent with BEACOPP. Nevertheless, even in this high-risk group, OS was not improved with BEACOPP. Additional considerations (treatment burden and cost, fertility issues, long term relapses and immediate and late morbidity) may guide physician/patient decisions toward ABVD or BEACOPP.

Follow-up of [11C]PIB uptake and brain volume in patients with Alzheimer disease and controls

OBJECTIVE

In Alzheimer disease (AD), the accumulation pattern of beta-amyloid over time and its relationship with dementia severity are unclear. We investigated the brain uptake of the amyloid ligand (11)C-labeled Pittsburgh compound B ([(11)C]PIB) and volumetric brain changes over a 2-year follow-up in patients with AD and in aged healthy controls.

METHODS

Fourteen patients with AD (mean age 72 years, SD 6.6) and 13 healthy controls (mean age 68 years, SD 5.4) were examined at baseline and after 2 years (patients with AD: mean 2.0 years, SD 0.2; controls: mean 2.1 years, SD 0.6) with [(11)C]PIB PET, MRI, and neuropsychological assessments. [(11)C]PIB uptake was analyzed with a voxel-based statistical method (SPM), and quantitative data were obtained with automated region-of-interest analysis. MRI data were analyzed with voxel-wise tensor-based morphometry.

RESULTS

The [(11)C]PIB uptake of the patients with AD did not increase significantly during follow-up when compared with that of the controls. MRI showed progressive brain volume change in the patients with AD, e.g., in the hippocampal region, temporal cortex, and precuneus (p < 0.05). The mean Mini-Mental State Examination score of the patients with AD declined from 24.3 (SD 3.1) at baseline to 21.6 (SD 3.9) at follow-up (p = 0.009). Cognitive decline was also evident in other neuropsychological test results. Baseline neocortical [(11)C]PIB uptake ratios predicted subsequent volumetric brain changes in the controls (r = 0.725, p = 0.005).

CONCLUSIONS

The results suggest no (or only little) increase in (11)C-labeled Pittsburgh compound B ([(11)C]PIB) uptake during 2 years of Alzheimer disease progression, despite advancing brain atrophy and declining cognitive performance. Nevertheless, changes in [(11)C]PIB uptake during a longer follow-up cannot be excluded. High cortical [(11)C]PIB uptake may predict ongoing brain atrophy in cognitively normal individuals.

Cationic liposomal paclitaxel in combination with gemcitabine in patients with advanced pancreatic cancer: A phase II trial

4526

Background: EndoTAG-1 is a novel cationic liposomal formulation of paclitaxel being developed for the treatment of solid malignancies. It acts by targeting activated negatively charged endothelial cells of tumor blood vessels. We present safety and efficacy data of a randomized, controlled phase II trial in pancreatic cancer (PC). Methods: 200 patients with advanced PC were randomized to 1st line treatment with weekly gemcitabine (GEM: 1000 mg/m2) and twice weekly infusions of EndoTAG-1 (E) at 3 different dose levels (Elow: 11 mg/m2, Emed: 22 mg/m2, Ehigh: 44 mg/m2) or GEM monotherapy. Patients were treated for 7 weeks and followed up for overall survival (OS) for at least 1 year. After finishing study treatment, any anti-tumor therapy was allowed. A subgroup of patients had the option to receive repeated cycles of combination therapy in case of at least stable disease according to RECIST until disease progression. Results: Median OS was substantially higher in the GEM+Emed and GEM+ Ehigh groups than the GEM monotherapy group. Adjusted hazard ratios for OS were 0.72 (95% CI 0.46–1.13) and 0.67 (0.43–1.07). In patients receiving >1 treatment cycle, median OS was 11.5 months (GEM+Ehigh); in the GEM+Emed group 75% of patients were alive at 1 year. Treatment with EndoTAG-1 and gemcitabine was generally well tolerated. A trend for increasing adverse event frequency with EndoTAG-1 dose was observed for infusion-related reactions associated with chills and pyrexia, and thrombocytopenia. The overall frequency of serious adverse events in the GEM+E groups was low, the most frequent SAE being pyrexia in 4 (8%) patients in the GEM+Ehigh group. There was no indication for significant organ toxicity associated with EndoTAG-1, even in patients receiving multiple treatment cycles. Conclusions: This phase II trial indicates a considerable survival benefit for patients with advanced PC receiving EndoTAG-1 in combination with gemcitabine and a favourable safety profile warranting further development of EndoTAG-1 in this indication.

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Treatment of recurrent malignant glioma with G207, a genetically engineered herpes simplex virus-1, followed by irradiation: Phase I study results

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Background: G207 is a doubly mutated (deletion of both γ134.5 loci, insertional inactivation of UL39) herpes simplex virus (HSV)-1. Safety and efficacy of intracerebral inoculations of G207 to patients suffering from recurrent malignant gliomas have been demonstrated in previous clinical trials. Methods: In this phase I clinical trial, a total of 1 x 109 plaque forming units (pfu) G207 were administered by five stereotactic injections of 0.2 mL each into regions of recurrent malignant glioma defined by MRI, followed by focal radiation therapy 24 hours post injection. Included patients suffered from inoperable pathologically proven recurrent glioblastoma multiforme (GBM) or anaplastic astrocytoma (AA) which was progressive despite radiotherapy or chemotherapy and failed external beam radiotherapy > 5 Gray prior to study enrolment. Results: 9 patients were treated in this phase I study. 5 patients were suffering from relapsed GBM, 4 patients were suffering from relapsed AA. 1 month after treatment, 3 patients (3xGBM) showed SD, 2 patients (1xGBM, 1xAA) PR, and 4 patients (1xGBM, 3xAA) PD. The 2 patients with initial PR (1xGBM, 1xAA) were re-treated with G207/Irradiation at time point of tumor recurrence, showing PR one month after re-treatment again. Median overall survival time for all 9 patients was 229 days (7.6 months), with one patient still alive at time of abstract submission. In patients suffering from relapsed GBM, mOS was 7.4 months, in patients suffering from relapsed AA, mOS was 9.25 months. 20 serious adverse events occurred in this study, only 3 were possible/probable related to G207/irradiation. Within persistent areas of tumor, HSV staining was present by using a polyclonal antibody for HSV, indicating intratumoral G207 replication (proof of concept). Conclusions: In 9 patients suffering from relapsed GBM or AA, stereotactic intracerebral G207 inoculation followed by radiation therapy was feasible, safe, and induced clinically relevant responses. G207/Irradiation re-treatment was possible and induced anew clinical responses. Median overall survival is superior to published data in this patient population. Therefore, further clinical development of G207 in GBM is medically reasonable.

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Voxel-based analysis of cerebral glucose metabolism in mono- and dizygotic twins discordant for Alzheimer disease

BACKGROUND

Sporadic Alzheimer disease (AD) is a multifactorial disease to which both genetic and environmental factors contribute. Therefore, twin pairs are useful in studying its pathogenesis and aetiology. Cerebral glucose metabolism has been found to be reduced in AD patients.

METHODS

Cerebral glucose metabolism was studied in seven monozygotic (MZ) and nine same-sexed dizygotic (DZ) twin pairs discordant for AD using positron emission tomography. To obtain objective and explorative results concerning differences in glucose metabolism, the analysis was performed utilising modern voxel-based analysis methodology statistical parametric mapping and automated region-of-interest analysis.

RESULTS

In the demented MZ and DZ co-twins, cerebral glucose metabolism was extensively reduced compared with controls. The non-demented MZ co-twins showed reduced metabolism in inferior frontal, lateral temporal, parietal and medial temporal cortices as well as in the thalamus, putamen and right amygdala. In contrast, no reductions were found in the non-demented DZ co-twins. The reduction found in the non-demented MZ co-twins may be an indicator of genetic susceptibility to AD.

A herpes oncolytic virus can be delivered via the vasculature to produce biologic changes in human colorectal cancer

Genetically engineered herpes simplex viruses (HSVs) can selectively infect and replicate in cancer cells, and are candidates for use as oncolytic therapy. This long-term report of a phase I trial examines vascular administration of HSV as therapy for cancer. Twelve subjects with metastatic colorectal cancer within the liver failing first-line chemotherapy were treated in four cohorts with a single dose (3 x 10(6) to 1 x 10(8) particles) of NV1020, a multimutated, replication-competent HSV. After hepatic arterial administration, subjects were observed for 4 weeks before starting intra-arterial chemotherapy. All patients exhibited progression of disease before HSV injection. During observation, levels of the tumor marker carcinoembryonic antigen (CEA) decreased (median % drop = 24%; range 13-74%; P < 0.02). One of three individuals at the 10(8) level showed a 39% radiologic decrease in tumor size by cross-section and 75% by volume. HSV infection was documented from liver tumor biopsies. After beginning regional chemotherapy, all patients demonstrated a further decrease in CEA (median 96%; range 50-98%; P < 0.008) and a radiologic partial response. Median survival for this group was 25 months. During follow-up, no signs of virus reactivation were found. Multimutated HSV can be delivered safely into the human bloodstream to produce selective infection of tumor tissues and biologic effects.

Phase Ib trial of mutant herpes simplex virus G207 inoculated pre-and post-tumor resection for recurrent GBM

We have previously demonstrated safety of G207, a doubly mutated (deletion of both gamma(1)34.5 loci, insertional inactivation of U(L)39) herpes simplex virus (HSV) for patients stereotactically inoculated in enhancing portions of recurrent malignant gliomas. We have now determined safety of two inoculations of G207, before and after tumor resection. Inclusion criteria were histologically proven recurrent malignant glioma, Karnofsky score >or=70, and ability to resect the tumor without ventricular system breach. Patients received two doses of G207 totaling 1.15 x 10(9) plaque-forming units with 13% of this total injected via a catheter placed stereotactically in the tumor. Two or five days later, tumor was resected en bloc with catheter in place. The balance of G207 dose was injected into brain surrounding the resection cavity. Six patients with recurrent glioblastoma multiforme were enrolled. Two days after the second G207 inoculation, one patient experienced transient fever, delirium, and hemiparesis, which entirely resolved on high-dose dexamethasone. No patient developed HSV encephalitis or required treatment with acyclovir. Radiographic and neuropathologic evidence suggestive of antitumor activity is reported. Evidence of viral replication was demonstrated. G207 appears safe for multiple dose delivery, including direct inoculation into the brain surrounding tumor resection cavity.

Vaccination trial with HPV16 L1E7 chimeric virus-like particles in women suffering from high grade cervical intraepithelial neoplasia (CIN 2/3)

Persistent infection with human papillomaviruses (HPV) is a prerequisite for the development of cervical cancer. Vaccination with virus-like particles (VLP) has demonstrated efficacy in prophylaxis but lacks therapeutic potential. HPV16 L1E7 chimeric virus-like particles (CVLP) consist of a carboxy-terminally truncated HPV16L1 protein fused to the amino-terminal part of the HPV16 E7 protein and self-assemble by recombinant expression of the fusion protein. The CVLP are able to induce L1- and E7-specific cytotoxic T lymphocytes. We have performed a first clinical trial to gain information about the safety and to generate preliminary data on the therapeutic potential of the CVLP in humans. A randomized, double blind, placebo-controlled clinical trial has been conducted in 39 HPV16 mono-infected high grade cervical intraepithelial neoplasia (CIN) patients (CIN 2/3). Two doses (75 mug or 250 mug) of CVLP were applied. The duration of the study was 24 weeks with 2 optional visits after another 12 and 24 weeks. The vaccine showed a very good safety profile with only minor adverse events attributable to the immunization. Antibodies with high titers against HPV16 L1 and low titers against HPV16 E7 as well as cellular immune responses against both proteins were induced. Responses were equivalent for both vaccine concentrations. A trend for histological improvement to CIN 1 or normal was seen in 39% of the patients receiving the vaccine and only 25% of the placebo recipients. Fifty-six percent of the responders were also HPV16 DNA-negative by the end of the study. Therefore, we demonstrated evidence for safety and a nonsignificant trend for the clinical efficacy of the HPV16 L1E7 CVLP vaccine.

A double-blind randomized multicentre clinical trial to evaluate the efficacy and safety of two doses of etomoxir in comparison with placebo in patients with moderate congestive heart failure: the ERGO (etomoxir for the recovery of glucose oxidation) study

Etomoxir is an inhibitor of mitochondrial CPT1 (carnitine palmitoyltransferase 1) and thereby switches energy metabolism from fatty acids to glucose oxidation. Such a metabolic change may be beneficial in CHF (congestive heart failure). The ERGO (etomoxir for the recovery of glucose oxidation) study was designed in which etomoxir was tested at a dose of 80 and 40 mg compared with placebo for a period of 6 months in patients with CHF. As the principle measure of efficacy, a maximal exercise tolerance test and a submaximal 6-min corridor walk test were used. Secondary end points were echocardiographical dimensions and quality-of-life assessment scores. A total of 350 patients were planned to be screened, with the expectation that end point data would be available from approx. 260 patients. However, the study had to be stopped prematurely, because unacceptably high liver transaminase levels were detected in four patients taking etomoxir. At the termination of the study, 121 patients were randomized to placebo, 118 to 40 mg of etomoxir and 108 to 80 mg of etomoxir. At that time, 21 patients in the placebo group, 16 in the 40 mg of etomoxir group and 14 patients in the 80 mg of etomoxir group had completed the study. The mean increases in exercise time were 3.3, 10.2 and 19.4 s for the placebo, 40 mg of etomoxir and 80 mg of etomoxir groups respectively (P value was not significant). No changes were obvious in the 6-min corridor walk test or in echocardiographical parameters from baseline. The number of patients that completed the study was too small to demonstrate significant effects on exercise time, although there was a tendency towards an increase in exercise time. Therefore, before rejecting the hypothesis that inhibition of fatty acid oxidation might be beneficial in CHF, similar studies have to be performed using different inhibitors of fatty acid oxidation targeting CPT1 and other enzymes in this metabolic pathway.

Phase I, Open-Label, Dose-Escalating Study of a Genetically Engineered Herpes Simplex Virus, NV1020, in Subjects with Metastatic Colorectal Carcinoma to the Liver

Current regimens of systemic chemotherapy result in only modest lengthening of survival in patients with advanced stage, liver-dominant, metastatic colorectal cancer who have failed first-line chemotherapy. The objective of this study was to investigate the safety and tolerability of NV1020, a replication-competent, attenuated, genetically engineered herpes simplex virus type 1 (HSV-1), in patients with hepatic colorectal metastases refractory to first-line chemotherapy. A phase I, open-label, dose-escalating study of a single 10-min hepatic arterial infusion of NV1020 in four cohorts. Three patients in each cohort received doses of 3 x 10(6), 1 x 10(7), 3 x 10(7), and 1 x 10(8) plaque-forming units. Adverse events were either mild or moderate in severity, and self-limiting. Only three serious adverse events (one transient rise in serum y-glutamyltransferase, one diarrhea, and one leukocytosis) experienced by three patients were considered to be possibly or probably related to NV1020. There were no deaths during the study, and there was no evidence of disseminated herpes infection. Viral presence was detected in only one saliva sample and two serum samples from one asymptomatic patient in the highest dose cohort. In the first week after viral administration only rare and minor increases were noted for tumor necrosis factor-alpha (six samples; three patients; peak, 40 pg/ml), interleukin (IL)-1 (two samples; two patients; peak, 28 pg/ml), and interferon-y (four samples; two subjects; peak, 54 pg/ml). No IL-2 was detected. Mild liver enzyme elevations were self-limiting and not associated with clinical symptoms. We conclude that NV1020, a genetically engineered but replication-competent HSV-1 oncolytic virus, can be safely administered into the hepatic artery without significant effects on normal liver function.

CERAD test performances in amnestic mild cognitive impairment and Alzheimer's disease

OBJECTIVES

The aim of the study was to examine the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) test performances cross-sectionally in patients suffering from amnestic mild cognitive impairment (MCI) and mild Alzheimer's disease (AD). Moreover, we wanted to determine the sensitivity to amnestic MCI and mild AD, as well as the specificity of different CERAD subtests in our study groups.

MATERIAL AND METHODS

Fifteen healthy elderly individuals, 15 amnestic MCI patients and 15 probable AD patients suffering from mild dementia were tested with the CERAD neurocognitive dementia screening test.

RESULTS

Significant differences were found in all CERAD tests except Constructional praxis (copy) and Clock drawing between the controls and the AD group. The MCI group was differentiated from the controls only in the Wordlist learning test. In the language tests the sensitivity to MCI and AD was quite low and the specificity very high. In the savings scores the sensitivity to AD was high, but the specificity rather low. The Wordlist recognition test screened no false positives using the current cut-off score and the sensitivity to AD was 0.6, but only one MCI patient was detected using the current cut-off score. Raising the cut-off score also raised the sensitivity to MCI without dramatic loss of specificity. Cut-off scores for the Wordlist learning test and Wordlist delayed recall, which have been found to differentiate normal aging from dementia, are lacking in the Finnish CERAD. The current data indicates that the Wordlist learning test might be relatively sensitive to MCI.

CONCLUSIONS

The results indicate that the Finnish CERAD test battery with its current cut-off scores has low sensitivity to MCI, and using it as a sole cognitive screening instrument for MCI and preclinical dementia might result in false negatives.

Age, education and test performance on the Finnish CERAD

OBJECTIVES

The purpose of this study was to clarify the effects of age and education on CERAD (Consortium to Establish a Registry for Alzheimer's Disease) test performances.

MATERIAL AND METHODS

We present preliminary data on CERAD test results for a sample of elderly normal Finns (n = 40, age 58-85 years).

RESULTS

Our results show no significant correlation between age and CERAD test results. Significant differences were found between subjects with low versus high education in nine CERAD test scores. The mean scores in the low-education group were near the cut-off point in the naming test, whereas the mean scores of the high-education group nearly reached the ceiling on six test scores. These differences were evident in the wordlist learning test, which has previously been argued to be unaffected by educational level. Savings scores were unaffected by education.

CONCLUSION

The results underline the importance of taking into account the educational level of persons with subjective memory complaints when screening with CERAD for mild cognitive impairment and preclinical Alzheimer's disease.

Cortical activation related to auditory semantic matching of concrete versus abstract words

OBJECTIVE

The aim of this study was to examine cortical correlates of semantic memory processes in the auditory stimulus modality.

METHODS

Event-related desynchronization (ERD) and synchronization (ERS) of the lower (8-10 Hz) and upper (10-12 Hz) alpha frequency bands of background EEG were studied in 10 subjects performing an auditory semantic matching task. The stimuli were abstract and concrete nouns which were presented sequentially in pairs. The task was to decide whether the two nouns belonged to the same semantic category or not.

RESULTS

The presentation of the first stimulus (encoding) elicited ERS whereas the presentation of the second stimulus (semantic matching) elicited ERD. Abstract nouns presented as the second stimulus elicited ERD which was most prominent in the lower alpha frequency band, whereas the presentation of a concrete noun as the first stimulus elicited ERS, most prominently in the upper alpha frequency band.

CONCLUSIONS

The auditorily elicited ERD/ERS reflects cortical activity associated with cognitive functions. The present findings demonstrate that the auditorily elicited ERD/ERS can reveal subtle differences in auditory information processing. Semantic memory processes (encoding and comparison) are reflected as varying responses in the two alpha frequency bands.

Event-related desynchronization and synchronization during an auditory lexical matching task

OBJECTIVES

Event-related desynchronization (ERD) and synchronization (ERS) of the 8-10 and 10-12 Hz frequency bands of the background EEG were studied in 10 subjects performing an auditory lexical matching task.

METHODS

The stimuli were words and pseudowords presented sequentially in pairs. The subject was prompted to answer whether the two stimuli shared the same lexical status (words or pseudowords).

RESULTS

Regardless of lexicality, the presentation of the first stimulus elicited a significant late frontal ERD in both alpha frequency bands. When preceded by a pseudoword, the presentation of the second stimulus elicited a significant ERS at 200-400 ms and a significant, long-lasting and topographically-widespread ERD at 600-2200 ms in both frequency bands. When preceded by a word, the second stimulus did not elicit ERS in the initial time window, but a late ERD which was similar to the one observed in the previous condition. The complexity of ERD/ERS changes in the present task was revealed by significant interactions that time had with frequency band, stimulus type, stimulus order and lexicality of the preceding stimulus.

CONCLUSIONS

The results suggest that ERD/ERS does not reflect primary auditory stimulus processing. Rather, the ERD/ERS observed in this experiment most probably reflected task difficulty and differences between lexical-semantic and phonological memory functions.

Formylmethanofuran dehydrogenases from methanogenic Archaea. Substrate specificity, EPR properties and reversible inactivation by cyanide of the molybdenum or tungsten iron-sulfur proteins

Formylmethanofuran dehydrogenases, which are found in methanogenic Archaea, are molybdenum or tungsten iron-sulfur proteins containing a pterin cofactor. We report here on differences in substrate specificity, EPR properties and susceptibility towards cyanide inactivation of the enzymes from Methanosarcina barkeri, Methanobacterium thermoautotrophicum and Methanobacterium wolfei. The molybdenum enzyme from M. barkeri (relative activity with N-formylmethanofuran = 100%) was found to catalyze, albeit at considerably reduced apparent Vmax, the dehydrogenation of N-furfurylformamide (11%), N-methylformamide (0.2%), formamide (0.1%) and formate (1%). The molybdenum enzyme from M. wolfei could only use N-furfurylformamide (1%) and formate (3%) as pseudosubstrates. The molybdenum enzyme from M. thermoautotrophicum and the tungsten enzymes from M. thermoautotrophicum and M. wolfei were specific for N-formylmethanofuran. The molybdenum formylmethanofuran dehydrogenases exhibited at 77 K two rhombic EPR signals, designated FMDred and FMDox, both derived from Mo as shown by isotopic substitution with 97Mo. The FMDred signal was only displayed by the active enzyme in the reduced form and was lost upon enzyme oxidation; the FMDox signal was displayed by an inactive form and was not quenched by O2. The tungsten isoenzymes were EPR silent. The molybdenum formylmethanofuran dehydrogenases were found to be inactivated by cyanide whereas the tungsten isoenzymes, under the same conditions, were not inactivated. Inactivation was associated with a characteristic change in the molybdenum-derived EPR signal. Reactivation was possible in the presence of sulfide.