Publications by authors named "Martin Obermeier"

Quantification of hepatitis C virus (HCV)-RNA in serum or plasma samples is an essential parameter in HCV diagnostics. Here, the NeuMoDx™Molecular System (Qiagen) was tested for the most common HCV genotypes and compared to the cobas c6800 system (Roche). HCV-RNA from 131 plasma/serum samples from chronically infected patients was determined in parallel on the NeuMoDx and c6800 systems.

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Background: The objective of this study was to investigate the utility of neutrophil gelatinase-associated lipocalin (NGAL) and calprotectin (CPT) to predict long-term graft survival in stable kidney transplant recipients (KTR).

Methods: A total of 709 stable outpatient KTR were enrolled >2 months post-transplant. The utility of plasma and urinary NGAL (pNGAL, uNGAL) and plasma and urinary CPT at enrollment to predict death-censored graft loss was evaluated during a 58-month follow-up.

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The COVID-19 pandemic illustrated the important role of diagnostic tests, including lateral flow tests (LFTs), in identifying patients and their contacts to slow the spread of infections. INSTAND performed external quality assessments (EQA) for SARS-CoV-2 antigen detection with lyophilized and chemically inactivated cell culture supernatant of SARS-CoV-2 infected Vero cells. A pre-study demonstrated the suitability of the material.

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Background: In May 2022, the monkeypox virus (MPXV) spread into non-endemic countries and the global community was quick to test the lessons learned from the SARS-CoV-2 pandemic. Due to its symptomatic resemblance to other diseases, like the non-pox virus varicella zoster (chickenpox), polymerase chain reaction methods play an important role in correctly diagnosing the rash-causing pathogen. INSTAND quickly established a new external quality assessment (EQA) scheme for MPXV and orthopoxvirus (OPXV) DNA detection to assess the current performance quality of the laboratory tests.

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Background: HIV-1 RNA quantification is a key component of treatment monitoring.

Objectives: To assess the performance of a redesigned HIV-1 RNA quantitative assay that uses a dual-target approach: Xpert® HIV-1 Viral Load (VL) XC.

Study Design: Fresh and frozen samples (N = 533) from HIV-1 positive patients tested with Abbott HIV-1 assays (Alinity m and RealTime [m2000]) were retested using the new Xpert XC assay.

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SARS-CoV-2, the cause of COVID-19, requires reliable diagnostic methods to track the circulation of this virus. Following the development of RT-qPCR methods to meet this diagnostic need in January 2020, it became clear from interlaboratory studies that the reported Ct values obtained for the different laboratories showed high variability. Despite this the Ct values were explored as a quantitative cut off to aid clinical decisions based on viral load.

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Background: Detection of SARS-CoV-2 infections relies on the use of sensitive, accurate and high throughput RT-PCR assays.

Objectives: We assessed the analytical performance of the Abbott RealTime SARS-CoV-2 (RT-SARS), Alinity m SARS-CoV-2 (AlinSARS) assays and compared the clinical performance of the RT-SARS, AlinSARS, and Alinity m Resp-4-Plex (Alin4Plex) assays to the Seegene Allplex assay (Allplex) and an inhouse test (Inhouse).

Results: We found 100 % positive percent agreement (PPA) and 100 % negative percent agreement (NPA) comparing RT-SARS and Allplex.

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Complexes based on nitrogen and sulfur containing ligands involving 3d metal centers are known for the electrocatalytic reduction of CO However, photocatalytical activation has rarely been investigated. We herein present results on the light-driven CO reduction using either Ir(dFppy) [, dFppy = 2-(4,6-difluorophenyl)pyridine] or [Cu(xant)(bcp)], (, xant = xantphos, bcp = bathocuproine) as photosensitizer in combination with TEA (triethylamine) as sacrificial electron donor. The 3d metal catalysts have either dptacn (dipicolyl-triazacyclononane, ) or dpdatcn (dipicolyl-diazathiocyclononane, ) as ligand framework and Fe, Co or Ni as central metal ion.

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The steady development of the antiretroviral therapy (ART) has led to a significant change in the demands on the quality of care. There are different regional challenges.It is a non-interventional, bicentric correlation study in the form of a retrospective data analysis including data of 43 HIV-positive patients in Greifswald and 1669 in Berlin.

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Objectives: Geno2pheno[coreceptor] is a widely used tool for the prediction of coreceptor usage (viral tropism) of HIV-1 samples. For HIV-1 CRF01_AE, a significant overcalling of X4-tropism is observed when using the standard settings of Geno2pheno[coreceptor]. The aim of this study was to provide the experimental backing for adaptations to the geno2pheno[coreceptor] algorithm in order to improve coreceptor usage predictions of clinical HIV-1 CRF01_AE isolates STUDY DESIGN: V3-sequences of 20 clinical HIV-1 subtype CRF01_AE samples were sequenced and analyzed by geno2pheno[coreceptor].

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COVID-19 is a highly contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Preventing in-hospital infections is crucial to protect patients and hospital staff. At the very beginning of the COVID-19 pandemic, the German Heart Center initiated obligatory wearing of surgical face masks for patients and employees, SARS-CoV-2 screening for all patients, and symptom-based testing for employees.

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Introduction: HIV infection has become a chronic, well-treatable disease and the focus of caretakers has shifted to diagnosis and treatment of comorbidities. Hypogonadism in elderly men with HIV might be of particular relevance, however, little is known about its epidemiology in contrast to non-infected peers and men with other chronic medical conditions, such as type 2 diabetes. This study aimed at comparing the prevalence of testosterone deficiency and functional hypogonadism in men 50 years in these three groups.

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Background: Nucleic acid testing is essential for the detection and quantification of HCV RNA in the diagnosis of HCV infection and treatment monitoring. The Alinity m HCV assay was recently developed by Abbott Molecular for rapid detection and quantification of HCV RNA on the fully automated, continuous, random-access Alinity m analyzer.

Objectives: Our study assessed the performance of the new Alinity m HCV assay for detection and quantification of HCV RNA in a large series of patient samples of various genotypes.

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Background: Accurate, rapid detection of HIV-1 RNA is critical for early diagnosis, treatment decision making, and long-term management of HIV-1 infection.

Objective: We evaluated the diagnostic performance of the Alinity m HIV-1 assay, which uses a dual target/dual probe design against highly conserved target regions of the HIV-1 genome and is run on the fully automated Alinity m platform.

Study Design: This was an international, multisite study that compared the diagnostic performance of the Alinity m HIV-1 assay to four commercially available HIV-1 assays routinely used in nine independent clinical laboratories.

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Background: Accurate molecular methods to detect and quantify hepatitis B virus (HBV) DNA are essential to diagnose chronic infections, guide treatment decisions, assess response to treatment, and determine risk of HBV-related complications. New generations of real-time HBV DNA assay platforms provide results in less than 2-3 h, with continuous loading of specimens and true random-access capability.

Objectives: We examined the clinical performance of the new Alinity m HBV assay, run on the fully automated, continuous, random-access Alinity m platform, to accurately detect and quantify HBV DNA in a large series of patient samples infected with different HBV genotypes frequently encountered in clinical practice.

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Article Synopsis
  • HIV-2 is primarily found in West Africa, with less familiarity in industrialized countries like those in Europe, leading to gaps in management knowledge.
  • The characteristics of HIV-2 differ from HIV-1, affecting its diagnosis, clinical progression, and treatment options, especially antiretroviral therapy.
  • The text consolidates research and expert insights on HIV-2 to propose standardized medical care practices in Western Europe, covering diagnostics, treatment options, drug resistance, and prevention strategies.
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Hepatitis C virus (HCV) antigen/antibody (Ag/Ab) assays offer the benefit of reducing the window period compared to assays that detect only HCV-Ab. In this study the performance of the Murex Ag/Ab (Murex, Abbott) and Monolisa Ag/Ab Ultra (Monolisa, Bio-Rad) ELISAs was compared for the use of filter dried serum/plasma spots (DS/PS) with a focus on the sensitivity and the percentage of correct positive test results. Correct positive ELISA results were assumed for samples that subsequently tested positive for HCV RNA by RT-qPCR, or RNA negative samples that tested positive in a Western blot (confirmed ELISA results).

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Monitoring recency of infection helps to identify current transmission in vulnerable populations for effective disease control. We have established an in-house avidity based hepatitis C virus (HCV) recency assay based on the Monolisa Anti-HCV PLUS Version 3 ELISA kit for use of dried serum/plasma spots (DS/PS) in order to distinguish recent and long-term infections. A first panel of DS/PS (n = 218; genotype 1 n = 170 and non-genotype 1 n = 48) consisting of primary and at least one follow up sample was used to analyze the temporal changes of the Avidity Index (AI) over time.

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The reactivity of phosphanyl phosphonates toward diacetylenic ketones was studied. Reactions resulted in the selective formation of phospholones via phosphaalkene intermediates. Phospholones were obtained in yields of 37-96% depending on the substituent on the acetylenic unit.

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High accuracy and precision at the lower end of quantification are crucial requirements of a modern HIV viral load (VL) assay, since some clinically relevant thresholds are located at 50 and 200 copies/ml. In this study, we compared the performance of two new fully automated HIV-1 VL assays, Aptima HIV-1 Quant Dx and Cobas HIV-1 (Cobas 6800), with the established RealTie 2000 assay. Assay precision and accuracy were evaluated in a retrospective evaluation out of excess plasma material from four HIV-1+ individuals (subtypes B, C, CRF01_AE, and CRF02_AG).

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Identifying resistance to antiretroviral drugs is crucial for ensuring the successful treatment of patients infected with viruses such as human immunodeficiency virus (HIV) or hepatitis C virus (HCV). In contrast to Sanger sequencing, next-generation sequencing (NGS) can detect resistance mutations in minority populations. Thus, genotypic resistance testing based on NGS data can offer novel, treatment-relevant insights.

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Background: The major resistance-associated substitution for sofosbuvir (S282T) in HCV NS5B causes severe viral fitness costs and rapidly reverts back to prototype in the absence of selection pressure. Accordingly, resistance against sofosbuvir is rarely detected even in patients after treatment failure.

Case Presentation: We report a case of a GT3a infected patient with viral breakthrough under SOF/DCV therapy.

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The face of hepatitis C virus (HCV) therapy is changing dramatically. Direct-acting antiviral agents (DAAs) specifically targeting HCV proteins have been developed and entered clinical practice in 2011. However, despite high sustained viral response (SVR) rates of more than 90%, a fraction of patients do not eliminate the virus and in these cases treatment failure has been associated with the selection of drug resistance mutations (RAMs).

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