Non-polio enteroviruses (NPEV) cause significant disease worldwide. Population-based sero-surveillance, by measuring antibodies against specific NPEV types, provides additional information on past circulation and the prediction for future upsurges. Virus neutralisation assays (VNA), the current method of choice for measuring NPEV type specific antibodies, are not entirely standardised. Via the European Non-Polio Enterovirus Network, we organised a VNA quality assessment in which twelve laboratories participated. We provided five echovirus (E) types (E1, E18, E30 G2, E30 G6 and E6) and intravenous immunoglobulins (IVIG) as a sample for the NPEV VNA quality assessment. Differences in VNA protocols and neutralising Ab (nAb) titres were found between the participating laboratories with geometric coefficients of variation ranging from 10.3-62.9 %. Mixed-effects regression analysis indicated a small but significant effect of type of cell line used. Harmonisation of cell line passage number, however, did not improve variation between laboratories. Calibration by making use of a reference sample, reduced variation between laboratories but differences in nAb titres remained higher than two log2 dilution steps. In conclusion, sero-surveillance data from different laboratories should be compared with caution and standardised protocols are needed.
- MeSH
- Echovirus Infections virology epidemiology immunology MeSH
- Enterovirus Infections virology immunology MeSH
- Enterovirus B, Human * immunology MeSH
- Humans MeSH
- Neutralization Tests * methods standards MeSH
- Antibodies, Neutralizing * blood immunology MeSH
- Antibodies, Viral * blood immunology MeSH
- Seroepidemiologic Studies MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Europe MeSH
Diagnosis of SARS-CoV-2 virus is mainly based on direct detection. Determination of specific antibodies has been used mostly for epidemiological reasons. However, select immunoassays showed good correlation to plaque reduction virus neutralization test (PRNT) in smaller patient cohorts, which suggests their potential as predictors of virus neutralization titer. A total of 3,699 samples from Covid-19 patients were included in the multicentric study performed in the Czech Republic. Anti-SARS-CoV-2 antibody levels were evaluated by 8 commercial antibody assays. Simultaneously, PRNT evaluations were performed with the SARS-CoV-2 B.1.258 variant. All immunoassays showed an overall high true positive diagnostic value ranging from 79.17 to 98.04%. Several commercial EIA methods showed highly positive correlation between the assay results and PRNT levels, e.g., Liaison CoV-2 TrimericS IgG DiaSorin (Spearman r = 0.8833; Architect SASRS-CoV-2 IgG Abbott (r = 0.7298); NovaLisa SARS-CoV-2 IgG NovaTec (r = 0.7103) and Anti-SARS-CoV-2 ELISA IgG Euroimmun (r = 0.7094). While this correlation was less positive for other assays, those, conversely, presented higher true positive values. For most immunoassays, the positive percent agreement of the results was ≥ 95% in sera exhibiting PRNT levels of 1:80 and higher. The assays tested have shown variable correlation to PRNT. Those possessing high positive predictive values serve well as qualitative tests, while others can be utilised as quantitative tests highly predictive of neutralization antibody levels.
Vztah mezi spalničkovým virem a lidským imunitním systémem je značně komplikovaný. Virus buňky imunitního systému potřebuje k navození systémové infekce, ve výsledku je ale imunitními mechanismy z organismu eliminován. Imunitní systém si ale z této interakce odnáší poškození ve formě ztráty části dosud získaného antigenního spektra paměťových buněk. Tato tzv. imunitní amnézie může po dobu minimálně několika měsíců zvyšovat náchylnost k nesouvisejícím infekcím. Účinným nástrojem v boji proti spalničkám je očkování, které vedlo k rozsáhlé eliminaci infekce. V posledních letech ale incidence spalniček vlivem různých faktorů opět narůstá. Pro zvládnutí tohoto trendu je důležité mít přehled o stavu imunity v populaci. Problémem pro jeho získání ale může být variabilita výsledků získaných v různých laboratořích komerčními soupravami různých výrobců, která vyplývá ze srovnání recentně publikovaných séroprevalenčních studií.
The relationship between measles virus and the human immune system is quite complicated. The virus needs cells of the immune system to induce a systemic infection, but as a result it is eliminated from the body by immune mechanisms. However, the immune system takes damage from this interaction in the form of the loss of part of the antigenic spectrum of memory cells acquired so far. This so-called immune amnesia can increase the susceptibility to unrelated infections for at least a few months. Vaccination is the effective tool in the fight against measles, which has led to extensive elimination of the infection. In recent years, however, the incidence of measles has increased again due to various factors. To cope with this trend, it is important to have an overview of the state of immunity in the population. The variability of the results obtained in different laboratories with commercial kits from different manufacturers, which results from a comparison of recently published seroprevalence studies, may be a problem for obtaining it.
- MeSH
- Child MeSH
- Adult MeSH
- Morbillivirus Infections immunology physiopathology MeSH
- Infant MeSH
- Humans MeSH
- Neutralization Tests methods statistics & numerical data MeSH
- Infant, Newborn MeSH
- Immunization Schedule MeSH
- Antibodies, Viral analysis MeSH
- Seroepidemiologic Studies MeSH
- Measles * epidemiology immunology physiopathology prevention & control MeSH
- Measles-Mumps-Rubella Vaccine MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Infant MeSH
- Humans MeSH
- Infant, Newborn MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
Two validated assays, a bridging ELISA and a luciferase-based bioassay, were compared for detection of anti-drug antibodies (ADA) against interferon-beta (IFN-β) in patients with multiple sclerosis. Serum samples were tested from patients enrolled in a prospective study of 18 months. In contrast to the ELISA, when IFN-β-specific rabbit polyclonal and human monoclonal antibodies were tested, the bioassay was the more sensitive to detect IFN-β ADA in patients' sera. For clinical samples, selection of method of ELISA should be evaluated prior to the use of a multi-tiered approach. A titer threshold value is reported that may be used as a predictor for persistently positive neutralizing ADA.
- MeSH
- Biological Assay MeSH
- Enzyme-Linked Immunosorbent Assay MeSH
- Immunologic Factors immunology therapeutic use MeSH
- Interferon-beta immunology therapeutic use MeSH
- Humans MeSH
- Neutralization Tests methods MeSH
- Antibodies, Neutralizing blood MeSH
- Multiple Sclerosis blood drug therapy MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
- Observational Study MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
JC virus (JCPyV) has gained novel clinical importance as cause of progressive multifocal leukoencephalopathy (PML), a rare demyelinating disease recently associated to immunomodulatory drugs, such as natalizumab used in multiple sclerosis (MS) cases. Little is known about the mechanisms leading to PML, and this makes the need of PML risk stratification among natalizumab-treated patients very compelling. Clinical and laboratory-based risk-stratification markers have been proposed, one of these is represented by the JCPyV-seropositive status, which includes about 54% of MS patients. We recently proposed to investigate the possible protective role of neutralizing humoral immune response in preventing JCPyV reactivation. In this proof-of-concept study, by cloning the first human monoclonal antibody (GRE1) directed against a neutralizing epitope on JCPyV/VP1, we optimized a robust anti-JCPyV neutralization assay. This allowed us to evaluate the neutralizing activity in JCPyV-positive sera from MS patients, demonstrating the lack of correlation between the level of anti-JCPyV antibody and anti-JCPyV neutralizing activity. Relevant consequences may derive from future clinical studies induced by these findings; indeed the study of the serum anti-JCPyV neutralizing activity could allow not only a better risk stratification of the patients during natalizumab treatment, but also a better understanding of the pathophysiological mechanisms leading to PML, highlighting the contribution of peripheral versus central nervous system JCPyV reactivation. Noteworthy, the availability of GRE1 could allow the design of novel immunoprophylactic strategies during the immunomodulatory treatment.
- MeSH
- Epitopes genetics immunology MeSH
- Antibodies, Monoclonal, Humanized adverse effects therapeutic use MeSH
- Cloning, Molecular MeSH
- Humans MeSH
- Antibodies, Monoclonal genetics immunology MeSH
- Neutralization Tests methods MeSH
- Antibodies, Neutralizing genetics immunology MeSH
- Polyomavirus immunology MeSH
- Leukoencephalopathy, Progressive Multifocal immunology prevention & control MeSH
- Antibodies, Viral genetics immunology MeSH
- Multiple Sclerosis therapy MeSH
- Capsid Proteins antagonists & inhibitors immunology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Sérologické vyšetření hraje v diagnostice chřipky důležitou roli, především v určení postvakcinačních a postinfekčních protilátek. Vzhledem k různým diagnostickým možnostem je nutné metodiku sérologického vyšetření volit podle konkrétních okolností – zda se jedná o párové sérum či jednovzorek, zda je k dispozici adekvátní anamnéza pacienta a případné epidemiologické souvislosti a především – jakému účelu bude výsledek sloužit (diferenciálnědiagnostická rozvaha, postinfekční sledování, postvakcinační zhodnocení). Virusneutralizace představuje jeden z nejcitlivějších a nejobjektivnějších sérologických testů, je však velmi závislá na přesném vyvážení reakce a kvalitě viru, který je do reakce použit. Stanovení protektivního titru je pro rutinní praxi nezbytné. V našem testovaní jsme došli k závěru, že virusneutralizační titry jsou v porovnání s HIT či KFR až osminásobně vyšší, korelace však není nikterak pevná a je významně ovlivněná individuální výší protilátek proti neuraminidáze a některým vnitřním proteinům. Autoři předběžně uzavírají, že výše protektivního titru ve virusneutralizačním testu bude nejméně 1 : 80. Informativní význam titrů nižších než 1 : 40 je sporný.
Serology plays an important role in the diagnosis of influenza, particularly in the detection of post-vaccination and post-infection antibodies. When considering the range of diagnostic options, the serological method should be selected depending on the circumstances – whether single or paired serum samples are tested, whether adequate patient medical history data are available, whether epidemiological links are suspected, and, in particular, to what purpose the result will be used (differential diagnosis, post-infection follow-up, post-vaccination monitoring, etc.). The virus neutralization assay is one of the most sensitive and most objective serological tests, but it is highly dependent on the reaction balance and quality of the virus used. Determining the protective titer is crucial for the routine practice. Based on our experiments, we concluded that the virus neutralizing antibody titers are up to eight times as high in comparison with the hemaglutination inhibition test (HIT) or complement fixation reaction (CFR), but the correlation varies and is significantly influenced by interindividual variation in anti-neuraminidase antibodies and those against some internal proteins of influenza virus. We assume that the protective titer in the virus neutralization assay will be not less than 1 : 80. The predictive value of the titers below 1 : 40 is questionable.
- Keywords
- virusneutralizace, virus chřipky, ochranné titry,
- MeSH
- Agglutination Tests methods utilization MeSH
- Influenza, Human diagnosis epidemiology virology MeSH
- Hemagglutination Tests methods utilization MeSH
- Clinical Laboratory Techniques methods utilization MeSH
- Complement Fixation Tests methods utilization MeSH
- Humans MeSH
- Neuraminidase antagonists & inhibitors isolation & purification blood MeSH
- Neutralization Tests methods utilization MeSH
- Pandemics prevention & control MeSH
- Polymerase Chain Reaction methods utilization MeSH
- Serologic Tests methods utilization MeSH
- Serology methods MeSH
- Statistics as Topic MeSH
- Hemadsorption Inhibition Tests methods utilization MeSH
- Hemagglutination Inhibition Tests methods utilization MeSH
- Influenza A Virus, H1N1 Subtype isolation & purification MeSH
- Influenza A virus isolation & purification MeSH
- Influenza B virus isolation & purification MeSH
- Check Tag
- Humans MeSH
Autoři upozorňují na diagnostická úskalí v sérologii klíšťové encefalitidy u očkovaných osob. Na konkrétní kazuistice pacientky se selháním očkování proti viru klíšťové encefalitidy je ilustrován přínos a omezení jednotlivých sérologických metod. U očkovaných pasntů s podezřením na klíšťovou encefalitidu je zdůrazněna nutnost vyšetření párových vzorků sér a průkaz signifikantní dynamiky v titru protilátek pro potvrzení diagnózy. Metodou volby je v těchto případech virusneutralizační test (VNT).
The authors draw attention to diagnostic pitfalls in tick born encephalitis serology in vaccinated people. Benefits and limitations of particular serologic methods are demostrated by case study of a patient with a failure of anti-TBEV vaccination. It is necessary to examine paired serum samples in previously vaccinated patients with suspicion of tick born encephalitis and to demonstrate significant increase of antibodies titers for confirmation of the diagnosis. The virusneutralisation assay is considered a method of choice in these special cases.
- MeSH
- Vaccines, Attenuated adverse effects therapeutic use MeSH
- Enzyme-Linked Immunosorbent Assay methods MeSH
- Encephalitis, Tick-Borne diagnosis prevention & control MeSH
- Complement Fixation Tests methods MeSH
- Humans MeSH
- Neutralization Tests methods MeSH
- Sensitivity and Specificity MeSH
- Viral Vaccines adverse effects therapeutic use MeSH
- Encephalitis Viruses, Tick-Borne isolation & purification MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
