Hilde Decraemer

Monitoring Drug Resistance in Chronic Hepatitis B Virus (HBV)-Infected Patients during Lamivudine Therapy: Evaluation of Performance of INNO-LiPA HBV DR Assay

ABSTRACT Sensitive and early detection of emerging hepatitis B virus (HBV) drug resistance may not only help monitor the viral dynamics associated with lamivudine treatment but could also improve therapeutic decision making. This is especially important when new antivirals effective against lamivudine-resistant HBV become available. A total of 159 serum samples from 33 chronic HBV patients receiving lamivudine treatment were analyzed at four centers for the presence of lamivudine-resistant mutations at codons 528 [180] (proposed revised nomenclature according to Stuyver et al. [Hepatology 33:751-757, 2001] shown in brackets), 552 [204], and 555 [207] of the HBV polymerase. Sequencing data were compared with results generated by the INNO-LiPA HBV DR line probe assay (LiPA), an assay based on reverse hybridization of amplified HBV DNA fragments with specific nucleotide probes immobilized on nitrocellulose strips. LiPA provided at least the same information as sequencing for 97.5% of all codons analyzed for codon 528 [180], 95% for codon 552 [204], and 100% for codon 555 [207]. The most common reason for discrepant or indeterminate results (0.4% and 1.5%, respectively) in a small percentage of the population tested could be attributed to polymorphisms not yet covered by LiPA probes. In at least five patients, a mutant could be detected earlier by LiPA than by sequencing. In 15 patients, LiPA detected mixed wild-type and mutant virus populations before viral breakthrough. These results demonstrate that INNO-LiPA HBV DR is a highly sensitive and easily applicable assay for the detection and monitoring of lamivudine-resistant mutations in chronic hepatitis B patients and that the assay is more sensitive than sequencing in detecting mixed mutant and wild-type sequences.

Increased CSF α-synuclein levels in Alzheimer's disease: Correlation with tau levels

Given the difficult clinical differential diagnosis between Alzheimers disease (AD) and dementia with Lewy bodies (DLB), growing interest resulted in research on α‐synuclein as a potential cerebrospinal fluid biomarker (CSF) for synucleinopathies.

Plasma tau protein in comatose patients after cardiac arrest treated with therapeutic hypothermia.

Neurological outcome after cardiac arrest (CA) is difficult to predict in the acute phase. In this pilot study, we assessed blood levels of tau protein as a prognostic marker for the neurological outcome after 6 months in patients treated with hypothermia after resuscitation from CA.

IMPROVEMENTS TO INNOTEST® PHOSPHO-TAU 181P

replicates and technical replicates were analyzed for 3 AD and 3 non-AD over ten consecutive days. For the vast majority of the peptides CVs were <5%. The second, 6 AD and 6 non-AD, indicated slightly increased levels of cystatin C, beta-2-microglobulin, and APP, as well as clearly increased levels of chromogranin A, secretogranin-2, and neurosecretory protein VGF for AD. Moreover, for complex samples the advantage of high resolution instrumentation became evident because of the superior possiblity to avoid signal interferences. Conclusions: The assay is reproducible and consumes little amount per analysis. Preliminary results should be interpreted with caution due to the limited sample material. Data from a larger study, using clinically well characterized samples, is under way and will be presented.

IMPROVEMENTS TO INNOTEST® HTAU AG

properties of these proteins and the interference of matrix components make the establishment of referencematerials very challenging. As a consequence up to now, the trust in the in commercial assays is limited. Since CSF quality control samples were not broadly available. Methods: A large number of individual CSF samples were pooled to establish 5 samples with different A b 1-42 and Ab 1-40 concentrations. Different compounds were added to the pools before lyophilization. The pools underwent one freeze-thaw cycle before aliquotation (250 ml, polypropylene screw-cap tubes). All aliquots were lyophilized and stored at -20 C. The consistency and homogeneity of the prepared panel was evaluated using three different lot numbers of the assays and analysis in 3 different laboratories by different users. In addition, the performance of the proficiency panel was integrated into a multicenter study and compared to performances of neat CSF or run-validation samples (1⁄4 analyte in buffer). Results: Addition of components do not affect analytical behavior of the CSF sample. Lyophilisation of the samples was successful. Stability was considerably increased by that procedure as analytes showed only 5% CV after one week at 37 C. Neat CSF, with and without the additives, as well as samples from the proficiency panel, showed a very good parallelism (1⁄4 absence of matrix interference in the assays) upon dilution for the three analytes evaluated in the study. The production process did not change the intrinsic characteristics of the CSF samples. Overall variability in a multicenter study for the proficiency panel did not exceed > 10%, including the sum of % CVof intra-run, inter-run, inter-operator, and inter-lab. Conclusions: A panel of 5 stabilized and lyophilized CSF samples with target values covering the whole range of the calibration curve of the A b 1-42 , Ab 1-40 and Total-Tau ELISA. The excellent precision data obtained in a multicenter study make this panel an excellent new tool to verify the quality of the biomarker measurements in research settings, but also for routine labs. In the absence of an international reference standard, this commercially available proficiency panel may significantly increase the trust in the values measured by ELISA of CSF diagnostics.

P-064: Measurement of β-amyloid isoforms in human plasma using the INNO-BIA plasma Aβ forms:(Pre)-clinical validation

(p 0 0001), whereas, after adjustment for age and sex, episodic memory and executive function did not. Baseline hippocampal atrophy was associated with increasing atrophy rates (hippocampal volume: p 0 025; MTA-score: p 0 008), in contrast whole brain volume, WMH and lacunes, adjusted for age and sex, were not significantly associated with hippocampal atrophy rates. Conclusions: In MCI, older age, poorer general cognition, hippocampal atrophy and APOE e4 predict subsequent accelerated rates of hippocampal atrophy, suggestive of the accumulation of Alzheimer-type pathology, which may become clinically manifest in the future. These markers may improve identification of MCI subjects at risk for AD.