HCV RNA and HIV RNA detection by Procleix HIV-1/HCV Assay in blood donors with various results of anti-HCV and anti-HIV EIA

Wstęp: Celem pracy była ocena czułości wykrywania RNA HIV i RNA HCV metodą Procleix HIV1/HCV oraz analiza częstości wykrywania materiału genetycznego wirusów u dawców z różnymi wynikami testów przeglądowych anty-HCV i anty-HIV. Materiał i metody:Dziewięćdziesięciopięcioprocentowa czułość testu Procleix wynosiła 6,2 IU RNA HCV /ml i 44,5 IU RNA HIV /ml. RNA HCV wykryto w 71/392 (18,1%) dodatnich próbkach anty-HCV, zaś RNA HIV w 21/557 (3,8%) próbkach reaktywnych w badaniu EIA HIV. Częstość wykrywania RNA HCV korelowała z wartością S/C uzyskaną w badaniach immunoenzymatycznych. RNA HCV wykryto u 68/105 (64,8%) dawców z S/C > 4, u 1/85 (1,2%) z S/C od 2,00 do 3,99 i u 2/202 dawców (1%) z S/C od 1,00 do 1,99. RNA HIV wykryto u wszystkich 21 dawców z dodatnimi wynikami zarówno w badaniu EIA, jak i w Western Blot. Wyniki i wnioski: Procleix HIV1/HCV jest bardzo czułym testem i może być wykorzystywany w laboratorium referencyjnym do potwierdzania aktywnego zakażenia u dawców z dodatnim wynikiem immunoezymatycznych badań przeglądowych. Obserwowano małą częstość aktywnych zakażeń u dawców z powtarzalnie dodatnimi wynikami badań anty-HCV i anty-HIV. Wysoka wartość S/C (> 4) w EIA jest dobrym czynnikiem prognostycznym wykrycia RNA HCV, aczkolwiek RNA HCV może być sporadycznie wykrywane u dawców z niższą wartością S/C w EIA.Background: The aim of the study was to investigate the sensitivity of Procleix HIV1/HCV Assay for HIV RNA and HCV RNA detection, and to analyse the frequency of viral nucleic acid detection in blood donors with various EIA test results. Material and methods: The 95% sensitivity of the Procleix test was 6.2 IU HCV RNA /ml and 44.5 IU HIV RNA /ml. HCV RNA was detected in 71/392 (18.1%) anti-HCV positive and HIV RNA in 21/557 (3.8%) EIA HIV-reactive donors. The frequency of HCV RNA detection correlated with signal/cut-off ratios (S/C ratio) of EIA. HCV RNA was found in 68/105 (64.8%) of the donors if it was >4, in 1/85 (1.2%) if it was between 2.00 and 3.99, and in 2 out of 202 donors (1%) if it was between 1.00 and 1.99. HIV RNA was detected in all 21 blood donors positive in EIA and Western Blot. Results and conclusions: The study demonstrated that Procleix HIV1/HCV Assay is very sensitive and can be used in the reference laboratory to confirm active infection in donors with positive results. We observed a low frequency of active infection in Polish blood donors with repeated reactive results in HCV and HIV EIA. The high S/C ratio value (> 4) of EIA is a good predictor of HCV RNA detection, but HCV RNA can also be detected in single donors with low ratio values of the EIA test

Poteškoće u određivanju protutijela štitnjače

Nowadays, different methods for determination of thyroglobulin autoantibodies (TGA), microsomal autoantibodies (TMA) and autoantibodies to enzyme thyroid peroxidase (TPO) have been developed. The specificity and sensitivity of these methods depend on the purity of autoantigen preparation itself, valid standardization and type of the methodology used, e.g., agglutination of gelatine particle carriers sensitized with antigen, radioimmunoassay (RIA), immunometric assay (IRMA), enzyme immunoassay (EIA) or luminometric assay (LIA). Although variable in their sensitivity and specificity, these tests are useful parameters in clinical practice, especially for patients with autoimmune thyroid disease, patients with differentiated thyroid cancer and pregnant women. Among six different methods (A-F) that were used in this study, four methods are based on the EIA principle, and one on the LIA and agglutination methodology each. Comparison of TGA, TMA and TPO values obtained by two, three and four methods in parallel was done on 527 frozen serum samples of outpatients. The concordance of TGA results was found to be in the range from 66% to 83% for two methods and 65% for three methods. The concordance of TMA/TPO results was in the range from 42% to 100% for two methods and 48% for four methods. The results suggest that the thyroid autoantibody methods need to be standardized and we are not yet certain which one of the methods is most reliable. False negative/positive TGA and TPO autoantibodies may cause a mistake in the diagnosis of autoimmune thyroid disease patients. Only an accurate, nonbiased TGA method can provide reliable TGA values that may interfere during thyroglobulin (Tg) measurement changing its concentration in serum of differentiated thyroid cancer patients.Danas postoji više metoda određivanja tireoglobulinskih i mikrosomskih protutijela štitnjače (TGA,TMA) kao i protutijela na enzim tiroidnu peroksidazu (TPO). Osjetljivost i specifičnost tih metoda ovise o čistoći antigena i standarda te o primijenjenoj metodologiji kao što su aglutinacijska metoda, radioimunološka (RIA), imunoradiometrijska (IRMA), enzimska (EIA) ili luminometrijska (LIA). Premda su te metode različitog stupanja osjetljivosti i specifičnosti, korisne su u praćenju bolesnika s autoimunim bolestima štitnjače (ATD), diferenciranim karcinomom štitnjače (DTC) i trudnica. Od šest metoda ( 4 TGA, 3 TPO, 1 TMA) primijenjenih u ovom radu četiri su bile EIA metode i po jedna LIA i aglutinacijska metoda. Usporedili smo rezultate TGA,TMA i TPO u serumu ambulantnih ispitanika (N= 527) koji su određeni sa dvije, tri i četiri metode. Podudarnost rezultata dviju TGA metoda kretala se u rasponu od 66% do 83%, a dviju TMA/TPO metoda u rasponu od 65%do 100%. Sukladnost triju TGA metoda i četiriju TMA/TPO metoda iznosila je 65% i 48%. Idealna, 100%-tna podudarnost TMA i TPO rezultata postignuta je metodama A i E (N= 33). Ovi rezultati ukazuju na potrebitost međunarodne standardizacije TGA i TPO metoda kojima bi se postigla veća ujednačenost tj. smanjio broj lažno pozitivnih ili lažno negativnih rezultata. Smatramo da se samo TGA metodom visoke osjetljivosti i specifičnosti može pouzdano odrediti TGA protutijela koja ponekad mogu utjecati na promjenu razine tireoglobulina (TG) u serumu bolesnika s diferenciranim karcinomom štitnjače. Lažno pozitivni ili negativni TGA i TPO rezultati također mogu utjecati na nepouzdanost dijagnoze bolesnika s ATD

Legionella pneumophila infections in Primorsko-goranska county

Cilj: Bakterije roda Legionella značajni su uzročnici nozokomijalnih pneumonija, kao i pneumonija koje se javljaju u zajednici. U većini slučajeva klinički nije moguće razlikovati pneumonije uzrokovane legionelama od onih nastalih ostalim atipičnim uzročnicima. Etiološka dijagnoza zasniva se prije svega na kultivaciji, detekciji antigena, serodijagnostici i molekularnim testovima. Metode: U radu smo retrospektivno analizirali rezultate pretraga izvršenih na Mikrobiološkom odjelu Nastavnog zavoda za javno zdravstvo u Rijeci od 2003. do 2008. godine. U našim laboratorijima u većini slučajeva legioneloza je dijagnosticirana detekcijom Legionella antigena u urinu i/ili imunoenzimskim (EIA) anti Legionella IgM pretragama kao najranijim serološkim pokazateljem infekcije. Rezultati: Sveukupno je obrađeno 97 uzoraka urina i 112 seruma prikupljenih od bolesnika s područja Primorsko-goranske županije. L. pneumophila O1 antigen otkriven je u 5 (5 %) od 97 uzoraka urina. Serološki je EIA metodom utvrđena prisutnost IgM protutijela u ukupno 13 obrađenih uzoraka (12 %). Samo IgM detektiran je u 4 (21 %), IgM plus IgA i IgG u 5 (26 %), IgM i IgA u 3 (16 %), IgM i IgG u 1 (5 %), i samo IgG protutijela u 6 (32 %) od 19 pozitivnih uzoraka seruma. U konačnici, u razdoblju od 2003. do 2008. godine pozitivni nalazi na bakteriju L. pneumophila utvrđeni su u uzorcima od ukupno 8 bolesnika. Rasprava i zaključci: Detekcija IgM protutijela primjenom osjetljive metode kao što je imunoenzimski test – EIA pokazala se pogodnom u kombinaciji s detekcijom antigena u urinu za dijagnostiku legioneloza. EIA za otkrivanje L. pneumophila seroskupine O1 antigena u urinu predstavlja specifičnu metodu koja je osobito značajna za brzu dijagnostiku legionarske bolesti.Aim: Bacteria of the genus Legionella are important causes of both community-acquired and nosocomial pneumonia. However, the majority of cases are clinically indistinguishable from other causes of pneumonia and it cannot be reliably diagnosed on clinical grounds alone. The etiological diagnosis depends mostly on culture, antigen detection, serological or molecular tests. Methods: Present paper represents the results of retrospective analysis of tests performed at the Department of Microbiology the Teaching Institute of Public Health in Rijeka between 2003 to 2008. In our laboratories most of the cases were diagnosed by the detection of Legionella antigen in urine and/or serological determination with enzyme immunoassay (EIA) test of the anti-Legionella IgM fraction as the most recent answer to infection. Results: Overall 97 urine samples and 112 sera of patients from Primorsko-Goranska County were analysed. L. pneumophila O1 antigen in urine was detected in 5 (5 %) of 97 samples. Serologically EIA detected IgM in overall 13 (12 %) of all samples tested. IgM only was found in 4 (21 %) samples, IgM plus IgA and IgG in 5 (26 %), IgM plus IgA in 3 (16 %), IgM plus IgG in 1 (5 %), and IgG alone was found in 6 (32 %) of 19 positive samples. Overall, from 2003 to 2008 L. pneumophila positive results were found in samples from 8 patients. Discussion and Conclusions: Detection of IgM using a sensitive technique such as EIA seems to be a suitable complement to antigenuria detection for the diagnosis of legionellosis. EIA for the detection of L. pneumophila serogroup O1 antigen in urine specimens is a specific assay which is of great importance in providing a rapid diagnosis of Legionnaires’ disease

Physical Activity and Asthma

Postoji suglasje znanstvene i stručne međunarodne javnosti da djecu i odrasle osobe s astmom treba poticati na sudjelovanje u redovitoj tjelesnoj aktivnosti jer ona povoljno djeluje na aktivnost bolesti te kvalitetu života. Astmatični napad, međutim, mogu izazvati brojni čimbenici, a među njima i tjelesno opterećenje. Uvriježen naziv za astmatični napad uzrokovan tjelesnim opterećenjem je “exercise-induced” astma (EIA). Taj fenomen može ometati astmatične osobe pri uključenju u školske, rekreativne i natjecateljske sportske aktivnosti te ograničiti njihova sportska postignuća. U ovom su radu opisani patofiziološki, klinički, dijagnostički i terapijski aspekti EIA. Prikazane su nefarmakološke mjere prevencije EIA, s posebnim osvrtom na pravilan odabir sportske discipline te prilagodbu trenažnog procesa kod astmatičara. Opisana su naša istraživanja pogodnosti hrvanja grčko-rimskim stilom i karatea za kondicioniranje školske djece s alergijskim bolestima, uključujući i astmu. Prikazane su specifičnosti uključenja osoba s astmom u sportske aktivnosti na međunarodnoj razini uz osvrt na antiastmatske lijekove koji se nalaze na listi zabranjenih supstancija Svjetske antidopinške agencije (WADA - World Anti-Doping Agency). Opisan je poseban oblik astme koja se pojavljuje u vrhunskih sportaša koji su respiratorno zdravi ušli u trenažni proces. Uzimajući u obzir navedene specifi čnosti EIA te današnje mogućnosti dijagnostike i liječenja tog poremećaja, astmatičar se, bez obzira na dob, može bez većih poteškoća uključiti u sportske aktivnosti, uz mogućnost za ostvarenje vrhunskih sportskih rezultata. Pri tome je nužna suradnja prosvjetnih, kinezioloških i medicinskih stručnjaka te redoviti zdravstveni nadzor astmatičnog sportaša uz prikladno liječenje, pravilan odabir sportske discipline te prilagodbu trenažnoga procesa.There is general agreement among experts that children and adults with asthma should be encouraged to participate in regular physical activity due to its benefi cial effects on disease activity and the patient’s quality of life. However, asthma attack can be provoked by exercise and the accepted term for this type of asthma attack is exercise-induced asthma (EIA). This phenomenon can interfere with involvement in school, recreational or top level sport activities, and limit achievements of asthmatic athletes. This article describes patophysiology, clinical features, diagnostic procedures, and therapy of EIA. We presented nonpharmacological preventive measures of EIA with particular attention to the selection of adequate sport discipline and adjustments of the training process for asthmatics. Furthermore, we reviewed our previous studies assessing Greco-Roman wrestling and non-contact karate in terms of their suitability for conditioning children with allergic diseases including asthma. We described the specifi cities of asthmatic top athletes participating in international competitions and we included the list of prohibited antiasthmatic drugs according to the World Anti-Doping Agency. We also presented a separate asthma phenotype which developed in top athletes who were respiratory healthy upon entry into training. With respect to all described specifi cities of EIA, modern diagnostic and therapeutic possibilities allow asthmatic persons to participate in various sport activities, even on top international level. Physical activities of asthmatics should be closely monitored and undertaken in cooperation with experts of kinesiology, education and sport medicine. They should also include regular health checkups, adequate asthma therapy, selection of appropriate sport discipline, and adjustments of training process

Enzyme immunoassay for separate detection of anti-HCV antibodies to individual HCV antigens as a confirmatory assay in diagnostics of HCV infection

Dijagnostika hepatitisa C temelji se na određivanju protutijela anti-HCV probirnim imunoenzimskim testovima (EIA). Svaki reaktivni nalaz anti-HCV probirnog testa prema recentnim smjernicama zahtijeva daljnje određivanje HCV RNK. U slučajevima negativnog nalaza HCV RNK, reaktivni nalaz EIA anti-HCV treba potvrditi imunoblot testom (IB). Komercijalno su dostupni i EIA testovi koji imaju mogućnost određivanja specifičnih protutijela na pojedinačne antigene HCV koji daju rezultate usporedive sa standardnim potvrdnim IB testovima. Cilj ovog rada bio je prikazati EIA potvrdni test, EIA-Anti-HCV-Spectrum (DSI, Italija) i usporediti rezultate testiranja sa standardnim IB testom. Analizirali smo 50 nasumično odabranih seruma koji su imali reaktivni odgovor protutijela na HCV u probirnom EIA testu (Monolisa HCV Ag-Ab ULTRA, Bio-Rad, Francuska). Za isključenje lažno pozitivnih rezultata serumi su dalje testirani potvrdnim IB testom (Deciscan HCV PLUS, Bio-Rad, Francuska). Odabranih 50 uzoraka testirano je testom EIA-Anti-HCV-Spectrum za određivanje pojedinačnih protutijela anti-HCV na antigene jezgre te antigene NS3, NS4 i NS5. Od 50 seruma s reaktivnim odgovorom protutijela na HCV u probirnom testu u oba potvrdna testa pozitivno je bilo 40, negativno 1 i granično 3 uzorka. Nepodudarnih rezultata potvrdnih testova bilo je 6: svi su bili granično pozitivni u IB testu, a negativni u alternativnom potvrdnom testu EIA-Anti-HCV-Spectrum. Predstavili smo imunoenzimski potvrdni test za protutijela anti-HCV koji je pokazao dobru korelaciju sa standardnim imunoblot testom premda je potrebno napraviti evaluaciju na ve}em broju uzoraka za sigurnije zaključke.Diagnostics of hepatitis C is based on the determination of anti-HCV antibodies by screening enzyme immunoassays (EIA). Each reactive anti-HCV screening result, according to recent guidelines, requires further determination of HCV RNA. In cases of negative HCV RNA findings, reactive anti-HCV results should be confirmed by immunoblotting (IB). Alternative confirmatory EIA with the ability to determine the antibodies against individual HCV antigens, which are comparable with the results of immunoblot tests, are commercially available. The aim of this study was to present an EIA test, the EIA-Anti-HCV-Spectrum (DSI, Italy) and compare the test results with standard IB test. We analyzed 50 randomly selected serum samples with reactive screening EIA (Monolisa HCV Ag-Ab ULTRA, Bio-Rad, France) results. In order to exclude false positives, serum samples were further tested with confirmatory IB test (Deciscan HCV PLUS, Bio-Rad, France). A total of 50 selected samples were tested with EIA-Anti-HCV-Spectrum for separate detection of anti-HCV antibodies against core, NS3, NS4 and NS5 antigens. Out of the 50 primary reactive samples, anti-HCV antibodies were positive in both confirmatory tests in 40, negative in 1 and borderline in 3 samples. Discordant results of confirmatory tests were recorded in 6 samples: all borderline in IB test and negative in the alternative EIA-Anti-HCV-Spectrum test. We present an EIA confirmatory test for anti-HCV antibodies which showed a good correlation with the standard immunoblot test, although it is ecessary to perform the evaluation on a large number of samples for safer conclusions

Preliminarno istraživanje učestalosti pojave bakterije Chlamydophila felis u domaće mačke u Gradu Zagrebu i na području Zagrebačke županije

This research was preliminary study of the presence and prevalence of Chlamydophila felis (Cp. felis) among domestic cats in the City of Zagreb and Zagreb County in Croatia. 48 pure and mixed breed cats were examined. 192 conjunctival and nasal swab samples were examined using a rapid immunoenzyme assay (EIA). 30 conjunctival scraping samples of 15 cats that were EIA positive were examined using DIF. Four of them were positive, while the results of two samples were inconclusive. These six samples (three nostril samples and three eye samples) were examined using a conventional polymerase chain reaction (PCR), and only two samples from the same cat were found to be positive for Cp. felis. The sequencing of the PCR product confirmed that the causative agent of the cat’s conjunctivitis was Cp. felis. By using direct immunofluorescence as well as a polymerase chain reaction procedure and sequencing, the results of the research established the existence of the bacteria Cp. felis in one out of 48 domestic cats.Cilj ovog preliminarnog istraživanja bio je ustanoviti učestalost pojave bakterije Chlamydophila felis (Cp. felis) u domaće mačke u Gradu Zagrebu i na području Zagrebačke županije. Istraživanjem je bilo obuhvaćeno 48 mačaka različitih pasmina. Brzim enzimskim imunološkim dijagnostičkim postupkom (EIA) pretraženo je 192 uzoraka obrisaka konjunktiva i nosnica te 12 uzoraka obriska sluznice rektuma. Trideset obrisaka konjuktiva s 15 mačaka, pozitivnih na EIA, pretraženo je postupkom izravne imunofluorescencije (DIF). Četiri su uzorka bila je pozitivna, a u dva je nalaz bio sumnjiv. Potom je tih šest uzoraka (tri uzoraka obriska nosne sluznice i tri obriska konjunktive) pretraženo postupkom lančane reakcije polimerazom (PCR). Dva su uzorka, podrijetlom s iste mačke, bila pozitivna. Rezultat sekvencioniranja produkta PCR dokazao je da je bolest u te domaće mačke bila uzrokovana upravo bakterijom Cp. felis. Korištenjem postupka izravne imunofluorescencije, lančane reacije polimerazom te sekvenciranjem produkta PCR dokazano je postojanje bakterije Cp. felis kao uzročnika mačje klamidioze u jedne od 48 mačaka

Forecasting the real price of oil in a changing world: a forecast combination approach : [Version November 13, 2013]

The U.S. Energy Information Administration (EIA) regularly publishes monthly and quarterly forecasts of the price of crude oil for horizons up to two years, which are widely used by practitioners. Traditionally, such out-of-sample forecasts have been largely judgmental, making them difficult to replicate and justify. An alternative is the use of real-time econometric oil price forecasting models. We investigate the merits of constructing combinations of six such models. Forecast combinations have received little attention in the oil price forecasting literature to date. We demonstrate that over the last 20 years suitably constructed real-time forecast combinations would have been systematically more accurate than the no-change forecast at horizons up to 6 quarters or 18 months. MSPE reduction may be as high as 12% and directional accuracy as high as 72%. The gains in accuracy are robust over time. In contrast, the EIA oil price forecasts not only tend to be less accurate than no-change forecasts, but are much less accurate than our preferred forecast combination. Moreover, including EIA forecasts in the forecast combination systematically lowers the accuracy of the combination forecast. We conclude that suitably constructed forecast combinations should replace traditional judgmental forecasts of the price of oil