CMV-, EBV-, and HHV-6-DNAemia after liver transplantation

Viral infections caused by herpesviruses are common complications after organ transplantation and they are associated with substantial morbidity and even mortality. Herpesviruses remain in a latent state in a host after primary infection and may reactivate later. CMV infection is the most important viral infection after liver transplantation. Less is known about the significance of human herpesvirus-6 (HHV-6). EBV is believed to play a major role in the development of post-transplant lymphoproliferative disorders (PTLD). The aim of this study was to investigate the CMV-, EBV- and HHV-6 DNAemia after liver transplantation by frequent monitoring of adult liver transplant patients. The presence of CMV, EBV and HHV-6 DNA were demonstrated by in situ hybridization assays and by real-time PCR methods from peripheral blood specimens. CMV and HHV-6 antigens were demonstrated by antigenemia assays and compared to the viral DNAemia. The response to antiviral therapy was also investigated. CMV-DNAemia appeared earlier than CMV pp65-antigenemia after liver transplantation. CMV infections were treated with ganciclovir. However, most of the treated patients demonstrated persistence of CMV-DNA for up to several months. Continuous CMV-DNA expression of peripheral blood leukocytes showed that the virus is not eliminated by ganciclovir and recurrences can be expected during several months after liver transplantation. HHV-6 DNAemia / antigenemia was common and occurred usually within the first three months after liver transplantation together with CMV. The HHV-6 DNA expression in peripheral blood mononuclear cells correlated well with HHV-6 antigenemia. Antiviral treatment significantly decreased the number of HHV-6 DNA positive cells, demonstrating the response to ganciclovir treatment. Clinically silent EBV reactivations with low viral loads were relatively common after liver transplantation. These EBV-DNAemias usually appeared within the first three months after liver transplantation together with betaherpesviruses (CMV, HHV-6, HHV-7). One patient developed high EBV viral loads and developed PTLD. These results indicate that frequent monitoring of EBV-DNA levels can be useful to detect liver transplant patients at risk of developing PTLD.Herpesvirusinfektiot aiheuttavat merkittäviä komplikaatioita ja jopa kuolleisuutta elinsiirtopotilailla. Herpesviruksille tyypillinen piirre on, että ne jäävät primaari-infektion jälkeen elimistöön piilevinä ja reaktivoituvat myöhemmin. Sytomegalovirus (CMV) infektio on kliinisesti tärkein maksansiirron jälkeen esiintyvä virusinfektio. Vähemmän tiedetään human herpesvirus-6:n (HHV-6) uusintainfektioista ja niiden merkityksestä elinsiirtojen jälkeen. Epstein-Barrin virus (EBV) voi aiheuttaa siirron jälkeisen lymfoproliferatiivisen tilan (PTLD). Tämän väitöskirjatutkimuksen tarkoituksena oli tutkia CMV-, EBV- ja HHV-6- DNA:n esiintymistä potilaan perifeerisessä veressä maksansiirron jälkeen. Tutkimuksen aineisto koostui aikuisista maksansiirtopotilaista, joita monitoroitiin säännöllisesti näiden virusten suhteen. CMV-, HHV-6- ja EBV- DNA osoitettiin in situ hybridisaatio-tekniikoiden ja reaaliaikaisten PCR-menetelmien avulla. CMV- ja HHV-6- antigeenit osoitettiin immunohistokemiallisin värjäyksin veren soluista ja antigenemiaa verrattiin viruksen DNAemiaan. Samalla tutkittiin myös viruslääkityksen tehoa. CMV DNA:n todettiin ilmaantuvan selvästi ennen CMV- pp65 antigeenia. Maksansiirtopotilaiden CMV infektiot hoidettiin gansikloviirillä. Kuitenkin useimmilla hoidetuilla potilailla CMV DNA:ta esiintyi perifeerisen veren soluissa jopa useita kuukausia. Jatkuva CMV-DNA ekspressio osoittaa, ettei virusta kyetä kokonaan eliminoimaan viruslääkkeellä ja näin uusintainfektiot ovat mahdollisia ensimmäisten kuukausien aikana maksansiirron jälkeen. HHV-6-DNA:ta /antigenemiaa esiintyi yleisesti maksansiirtopotilailla ensimmäisen kolmen kuukauden aikana maksansiirron jälkeen ja usein samanaikaisesti CMV infektion kanssa. Kun HHV-6 DNA osoitettiin maksansiirtopotilaiden perifeerisen veren mononukleaarisista soluista in situ-hybridisaation avulla, todettiin sen korreloivan hyvin HHV-6 antigenemiaan. Gansikloviiri hoidon todettiin laskevan merkitsevästi HHV-6 DNA-positiivisten solujen määrää näiden potilaiden veressä. Gansikloviiri hoidolla on täten mahdollisesti tehoa myös HHV-6 infektioon. EBV reaktivaatiot olivat melko yleisiä maksansiirron jälkeen. Nämä olivat EBV-DNAemia tasoltaan matalia ja esiintyivät yleensä ensimmäisen kolmen kuukauden aikana maksansiirron jälkeen yhdessä muiden herpesvirusten kanssa (CMV, HHV-6 ja HHV-7). Yhdellä potilaalla todettiin maksansiirron jälkeen korkeatasoinen EBV-DNAemia ja hänelle kehittyi PTLD. Säännöllinen EBV-DNA tasojen seuranta auttaa havaitsemaan ne potilaat, joille on vaarana kehittyä PTLD

Ripulivirusten pikadiagnostiikka

English summaryPeer reviewe

Virusdiagnostiset menetelmät : viljely, antigeeninosoitus vai nukleiinihaponosoitus?

Vertaisarvioitu. English summary. Teema : laboratoriotutkimukset• Nukleiinihapon osoitusmenetelmät ovat yleistyneet nopeasti virusdiagnostiikassa herkkyytensä vuoksi. Käytännössä ne ovat korvanneet diagnostiset virusviljelytutkimukset. • Vieritestauksessa käytetään yleisesti myös helppokäyttöisiä antigeeninosoitustestejä, mutta niiden suorituskyky vaihtelee. • Ns. pika-PCR-testit mahdollistavat nopeaa hoitoa varten tarvittavan pikadiagnostiikan esimerkiksi päivystysten tarpeisiin. • Menetelmät kehittyvät ja vaatimukset diagnostisille testeille kasvavat jatkuvasti, kuten käynnissä oleva koronapandemiakin on osoittanut. Uusien teknologioiden kehitystä tulee jatkuvasti seurata ja analysoida.Peer reviewe

Cytomegalovirus sequence variability, amplicon length, and DNase-sensitive non-encapsidated genomes are obstacles to standardization and commutability of plasma viral load results

Background: Cytomegalovirus (CMV) management post-transplantation relies on quantification in blood, but inter-laboratory and inter-assay variability impairs commutability. An international multicenter study demonstrated that variability is mitigated by standardizing plasma volumes, automating DNA extraction and amplification, and calibration to the 1st-CMV-WHO-International-Standard as in the FDA-approved Roche-CAP/CTMCMV. However, Roche-CAP/CTM-CMV showed under-quantification and false-negative results in a quality assurance program (UK-NEQAS-2014). Objectives: To evaluate factors contributing to quantification variability of CMV viral load and to develop optimized CMV-UL54-QNAT. Study design: The UL54 target of the UK-NEQAS-2014 variant was sequenced and compared to 329 available CMV GenBank sequences. Four Basel-CMV-UL54-QNAT assays of 361 bp, 254 bp, 151 bp, and 95 bp amplicons were developed that only differed in reverse primer positions. The assays were validated using plasmid dilutions, UK-NEQAS-2014 sample, as well as 107 frozen and 69 prospectively collected plasma samples from transplant patients submitted for CMV QNAT, with and without DNase-digestion prior to nucleic acid extraction. Results: Eight of 43 mutations were identified as relevant in the UK-NEQAS-2014 target. All Basel-CMV-UL54 QNATs quantified the UK-NEQAS-2014 but revealed 10-fold increasing CMV loads as amplicon size decreased. The inverse correlation of amplicon size and viral loads was confirmed using 1st-WHO-International-Standard and patient samples. DNase pre-treatment reduced plasma CMV loads by > 90% indicating the presence of unprotected CMV genomic DNA. Conclusions: Sequence variability, amplicon length, and non-encapsidated genomes obstruct standardization and commutability of CMV loads needed to develop thresholds for clinical research and management. Besides regular sequence surveys, matrix and extraction standardization, we propose developing reference calibrators using 100 bp amplicons.Peer reviewe

Cytomegalovirus infection of human kidney cells in vitro

Cytomegalovirus infection of human kidney cells in vitro. To study which structures of a kidney allograft are the main targets for cytomegalovirus (CMV), human glomerular epithelial and mesangial cells, as well as tubular epithelial and endothelial cells were isolated by steel meshes of different pore sizes and enzymatic treatments. The various cultured cell types were characterized by morphology and specific antibodies. Human CMV was inoculated onto cell monolayers using two different culture methods: conventional tissue culture and rapid shell vial culture. To analyze whether CMV had a direct effect on the immunologic properties of kidney parenchymal cells, MHC class I and class II antigen expression was estimated before and after the infection. CMV infected all kidney cells identically. All cells expressed class I strongly after the infection, but they were class I positive prior to infection. Class II antigens were not expressed on the cell surface either before or after the infection. In conclusion, human kidney cells of glomerular, tubular and vascular origin were all infected by CMV without any difference. CMV had no significant direct effects on the antigenic properties of the cells

Comparison of the clinical characteristics and outcomes of hospitalized adult COVID-19 and influenza patients - a prospective observational study

Background We compared the clinical characteristics, findings, and outcomes of hospitalized patients with coronavirus disease 2019 (COVID-19) or influenza to detect relevant differences. Methods From December 2019 to April 2020, we recruited all eligible hospitalized adults with respiratory infection to a prospective observational study at a tertiary care hospital in Finland. Influenza and SARS-CoV-2 infections were confirmed by RT-PCR. Follow-up lasted for 3 months from admission. Results We included 61 patients, of whom 28 were COVID-19 and 33 influenza patients with median ages of 53 and 56 years. Majority of both COVID-19 and influenza patients were men (61% vs. 67%) and had at least one comorbidity (68% vs. 85%). Pulmonary diseases and current smoking were less common among COVID-19 than influenza patients (5 [18%] vs. 15 [45%], p=.03 and 1 [4%] vs. 10 [30%], p=.008). In chest X-ray at admission, ground-glass opacities (GGOs) and consolidations were more frequent among COVID-19 than influenza patients (19 [68%] and 7 [21%], p.001). Severe disease and intensive care unit (ICU) admission occurred more often among COVID-19 than influenza patients (26 [93%] vs. 19 [58%], p=.003 and 8 [29%] vs. 2 [6%], p=.034). COVID-19 patients were hospitalized longer than influenza patients (six days [IQR 4-21] vs. 3 [2-4], p.001). Conclusions Bilateral GGOs and consolidations in chest X-ray may help to differentiate COVID-19 from influenza. Hospitalized COVID-19 patients had more severe disease, required longer hospitalization and were admitted to ICU more often than influenza patients, which has important implications for public health policies.Peer reviewe

METHOD FOR PRODUCING FOIL BLANK OF ALUMINUM-IRON-SILICON ALLOY

FIELD: metallurgy, namely processes of producing sheet blanks of melt for making coiled foil. SUBSTANCE: method comprises steps of casting strip blank in rolls-crystallizers by feeding melt at temperature 670 - 680°C, at temperature of rolls-crystallizers 20 - 30°C and at reduction value 50 - 55%. EFFECT: enhanced mechanical characteristics of foil blank, elimination of festoons formation on samples. 2 ex.Изобретение относится к области металлургии, а именно к технологии производства из расплава листовых заготовок и получения из них рулонной фольги. Отливку полосовой заготовки в валках-кристаллизаторах осуществляют путем подачи расплава при температуре 670-680°С и температуре валков-кристаллизаторов 20-30°С и ее обжатием величиной 50-55%. Изобретение позволяет повысить механические характеристики фольговой заготовки, а также исключить образование фестонов на изготавливаемых образцах

Real-life clinical sensitivity of SARS-CoV-2 RT-PCR test in symptomatic patients

Background Understanding the false negative rates of SARS-CoV-2 RT-PCR testing is pivotal for the management of the COVID-19 pandemic and it has implications for patient management. Our aim was to determine the real-life clinical sensitivity of SARS-CoV-2 RT-PCR. Methods This population-based retrospective study was conducted in March-April 2020 in the Helsinki Capital Region, Finland. Adults who were clinically suspected of SARS-CoV-2 infection and underwent SARS-CoV-2 RT-PCR testing, with sufficient data in their medical records for grading of clinical suspicion were eligible. In addition to examining the first RT-PCR test of repeat-tested individuals, we also used high clinical suspicion for COVID-19 as the reference standard for calculating the sensitivity of SARS-CoV-2 RT-PCR. Results All 1,194 inpatients (mean [SD] age, 63.2 [18.3] years; 45.2% women) admitted to COVID-19 cohort wards during the study period were included. The outpatient cohort of 1,814 individuals (mean [SD] age, 45.4 [17.2] years; 69.1% women) was sampled from epidemiological line lists by systematic quasi-random sampling. The sensitivity (95% CI) for laboratory confirmed cases (repeat-tested patients) was 85.7% (81.5-89.1%) inpatients; 95.5% (92.2-97.5%) outpatients, 89.9% (88.2-92.1%) all. When also patients that were graded as high suspicion but never tested positive were included in the denominator, the sensitivity (95% CI) was: 67.5% (62.9-71.9%) inpatients; 34.9% (31.4-38.5%) outpatients; 47.3% (44.4-50.3%) all. Conclusions The clinical sensitivity of SARS-CoV-2 RT-PCR testing was only moderate at best. The relatively high false negative rates of SARS-CoV-2 RT-PCR testing need to be accounted for in clinical decision making, epidemiological interpretations, and when using RT-PCR as a reference for other tests.Peer reviewe

SECTION FOR ELECTRICAL MACHINE COMMUTATOR

FIELD: metallurgy; copper and copper alloy half-finished products for electrical equipment. SUBSTANCE: proposed section for electrical machine commutator is equilateral-trapezium shaped in cross-sectional area perpendicular to section length. Part of this section abutting against smaller base of trapezium is made of copper and that abutting against larger base of trapezium is made of copper ally. Part of section abutting against larger base of trapezium can be made of cadmium bronze. EFFECT: enhance thermal stability and strength of commutator section. 2 cl, 5 dwg.Изобретение относится к области металлургии, а именно к полуфабрикатам электротехнического назначения, изготовляемым из меди и медных сплавов. Профиль для коллекторов электрических машин имеет форму равнобедренной трапеции в сечении, перпендикулярном длине профиля. Часть профиля, примыкающая к меньшему основанию трапеции, выполнена из меди, а часть профиля, прилегающая к большему основанию трапеции, выполнена из медного сплава. При этом часть профиля, прилегающая к большему основанию трапеции, может быть выполнена из кадмиевой бронзы. Технический результат от применения изобретения заключается в повышении теплостойкости и прочности коллекторного профиля. 1 з.п. ф-лы, 5 ил