HLA Class I alleles associated with HCV polymorphisms and response to antiviral therapy in HCV genotype 1-infected patients

Aims: The adaptive immune response against hepatitis C virus (HCV) is significantly shaped by the host's composition of HLA alleles. Thus, the HLA phenotype is a critical determinant of viral evolution during adaptive immune pressure. Potential associations of HLA class I alleles with polymorphisms of HCV immune escape variants are largely unknown. Methods: Direct sequence analysis of the genes encoding the HCV proteins E2, NS3 and NS5B in a cohort of 159 patients with chronic HCV genotype 1 infection who were treated with pegylated interferon-alfa 2b and ribavirin in a prospective controlled trial for 48 weeks was exhibited. HLA class I genotyping was performed by strand-specific reverse hybridization with the INNO-LiPA line probe assays for HLA-A and HLA-B and by strand-specific PCR-SSP. We analyzed each amino acid position of HCV proteins using an extension of Fisher's exact test for associations with HLA alleles. In addition, associations of specific HLA alleles with inflammatory activity, liver fibrosis, HCV RNA viral load and virologic treatment outcome were investigated. Results: Separate analyses of HCV subtype 1a and 1b isolates revealed substantially different patterns of HLA-restricted polymorphisms between subtypes. Only one polymorphism within NS5B (V2758x) was significantly associated with HLA B*15 in HCV genotype 1b infected patients (adjusted p=0,048). However, a number of HLA class I-restricted polymorphisms within novel putative HCV CD8+ T cell epitopes (genotype 1a: HLA-A*11 GTRTIASPK1086-1094 [NS3], HLA-B*07 WPAPQGARSL1111-1120 [NS3]; genotype 1b: HLA-A*24 HYAPRPCGI488-496 [E2], HLA-B*44 GENETDVLL530-538 [E2], HLA-B*15 RVFTEAMTRY2757-2766 [NS5B]) were observed with high predicted epitope binding scores assessed by the web-based software SYFPEITHI (>21). Most of the identified putative epitopes were overlapping with already otherwise published epitopes, indicating a high immunogenicity of the accordant HCV protein region. In addition, certain HLA class I alleles were associated with inflammatory activity, stage of liver fibrosis, and sustained virologic response to antiviral therapy. Conclusions: HLA class I restricted HCV sequence polymorphisms are rare. HCV polymorphisms identified within putative HCV CD8+ T cell epitopes in the present study differ in their genomic distribution between genotype 1a and 1b isolates, implying divergent adaptation to the host's immune pressure on the HCV subtype level.

Automated Segmentation of Cerebral Vasculature with Aneurysms in 3DRA and TOF-MRA using Geodesic Active Regions: an Evaluation Study

Purpose: To evaluate the suitability of an improved version of an automatic segmentation method based on geodesic active regions (GAR) for segmenting cerebral vasculature with aneurysms from 3D X-ray reconstruc-tion angiography (3DRA) and time of °ight magnetic resonance angiography (TOF-MRA) images available in the clinical routine.Methods: Three aspects of the GAR method have been improved: execution time, robustness to variability in imaging protocols and robustness to variability in image spatial resolutions. The improved GAR was retrospectively evaluated on images from patients containing intracranial aneurysms in the area of the Circle of Willis and imaged with two modalities: 3DRA and TOF-MRA. Images were obtained from two clinical centers, each using di®erent imaging equipment. Evaluation included qualitative and quantitative analyses ofthe segmentation results on 20 images from 10 patients. The gold standard was built from 660 cross-sections (33 per image) of vessels and aneurysms, manually measured by interventional neuroradiologists. GAR has also been compared to an interactive segmentation method: iso-intensity surface extraction (ISE). In addition, since patients had been imaged with the two modalities, we performed an inter-modality agreement analysis with respect to both the manual measurements and each of the two segmentation methods. Results: Both GAR and ISE di®ered from the gold standard within acceptable limits compared to the imaging resolution. GAR (ISE, respectively) had an average accuracy of 0.20 (0.24) mm for 3DRA and 0.27 (0.30) mm for TOF-MRA, and had a repeatability of 0.05 (0.20) mm. Compared to ISE, GAR had a lower qualitative error in the vessel region and a lower quantitative error in the aneurysm region. The repeatabilityof GAR was superior to manual measurements and ISE. The inter-modality agreement was similar between GAR and the manual measurements. Conclusions: The improved GAR method outperformed ISE qualitatively as well as quantitatively and is suitable for segmenting 3DRA and TOF-MRA images from clinical routine.

A Genetic Validation Study Reveals a Role of Vitamin D Metabolism in the Response to Interferon-Alfa-Based Therapy of Chronic Hepatitis C.

BACKGROUND: To perform a comprehensive study on the relationship between vitamin D metabolism and the response to interferon-α-based therapy of chronic hepatitis C. METHODOLOGY/PRINCIPAL FINDINGS: Associations between a functionally relevant polymorphism in the gene encoding the vitamin D 1α-hydroxylase (CYP27B1-1260 rs10877012) and the response to treatment with pegylated interferon-α (PEG-IFN-α) and ribavirin were determined in 701 patients with chronic hepatitis C. In addition, associations between serum concentrations of 25-hydroxyvitamin D(3) (25[OH]D(3)) and treatment outcome were analysed. CYP27B1-1260 rs10877012 was found to be an independent predictor of sustained virologic response (SVR) in patients with poor-response IL28B genotypes (15% difference in SVR for rs10877012 genotype AA vs. CC, p = 0.02, OR = 1.52, 95% CI = 1.061-2.188), but not in patients with favourable IL28B genotype. Patients with chronic hepatitis C showed a high prevalence of vitamin D insufficiency (25[OH]D(3)<20 ng/mL) during all seasons, but 25(OH)D(3) serum levels were not associated with treatment outcome. CONCLUSIONS/SIGNIFICANCE: Our study suggests a role of bioactive vitamin D (1,25[OH](2)D(3), calcitriol) in the response to treatment of chronic hepatitis C. However, serum concentration of the calcitriol precursor 25(OH)D(3) is not a suitable predictor of treatment outcome.

Lämpökuvaus laadunvarmistustyökaluna talonrakentamisessa

Tutkimuksen tavoitteena oli luoda NCC Rakennus Oy:lle uusi lämpökuvaus-toimintamalli, joka mahdollistaa rakentamisen ja rakennusten työvaiheiden laadunvarmistamisen entistä tehokkaammin. Tutkimuksessa käsiteltiin lämpökuvauksen perusteita, lämpökuvaustoiminnan roolia yrityksen laatujärjestelmässä ja erityispiirteitä eri työlajien laadunvarmistuksessa. Tutkimuksessa keskityttiin uudishankkeisiin toimitilarakentamisessa, asunto-, takuu- ja korjauspuolen aiheita käsiteltiin yleisesti. Insinöörityön lähdemateriaalina käytettiin lämpökuvaus- ja rakennuskirjallisuutta, yleisiä rakennusmääräyksiä ja -ohjeita, haastatteluja ja lämpökuvausraportteja. Teoriaosuuden jälkeen selvitettiin NCC:n kokemuksia lämpökuvauksesta ja kohteissa havaituista lämpöteknisistä ongelmakohdista. Kokeellisia lämpökuvauksia suoritettiin lämpökuvausolosuhteiden salliessa yhteensä seitsemässä toimitilakohteessa, yhdessä rivitalokohteessa, julkisivusaneerauskohteen 14:sta kerrostaloasunnossa ja yhdessä yksityisessä paritaloasunnossa. Toimintamalli osoittautui erittäin tarpeelliseksi ja tehokkaaksi rakennusten lämpöteknisen tiiveyden ja talotekniikan lämmitysjärjestelmien toiminnan varmistamisessa. Toistuvien lämpökuvausten aikana selvisi mittauslaitteiston ominaisuuksien merkitys, aputyökalujen ja tutkimusajan tarve sekä työnaikaisen lämpökuvausraportin rakenne. Insinöörityön tuloksena syntyi lämpökuvauksen avuksi toimintamalli, josta selviää rakennusvaiheittain lämpökuvauksen vaikutustapa, paikka, tiedonkulku, lämpökuvauksessa toistuvat vaiheet, osapuolet, tehtävät ja työkalut. Lämpökuvauksen avuksi luotiin aputyökaluja, jotka ovat avaintyölajien lämpökuvausohjekortit sekä suunnittelussa ja kuvaustilanteessa käytettävä apumateriaali kuten lämpökuvauksen tilauspohja, käyttäjätiedote, mittauspöytäkirja- pohja ja valmiit lämpötilaindeksien mukaiset pintalämpötilojen ohjearvotaulukot.