The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Adrian J F Luty - One of the best experts on this subject based on the ideXlab platform.
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the sickle cell trait is associated with enhanced ImmunoGlobulin G Antibody responses to plasmodium falciparum variant surface antiGens
The Journal of Infectious Diseases, 2005Co-Authors: Gerardo Cabrera, Florence Migotnabias, Peter G Kremsner, Philippe Deloron, Adrian J F LutyAbstract:The sickle cell trait (HbAS) protects aGainst severe Plasmodium falciparum malaria in younG African children. We investiGated the extent of the association between HbAS and antibodies directed to parasite-derived variant surface antiGens (VSAs) on the membrane of infected erythrocytes. We measured ImmunoGlobulin G (IGG) responses with specificity for VSAs of 2 heteroloGous parasite isolates in 458 Gabonese children aGed between 6 months and 11 years. LoGistic reGression analyses showed a hiGhly siGnificant independent association (P<.001) between carriaGe of HbAS and the presence of IGG anti-VSA responses; this association was related specifically to IGG1 and IGG4 subclasses in the anti-VSA profile. IGG2 and IGG3 anti-VSA responses were both independently associated with older aGe, consistent with the pattern observed in semi-immune adults. The results imply that enhanced levels of cross-reactive anti-VSA responses in children with HbAS may be intimately associated with the protection they have aGainst malaria.
Christine E Jones - One of the best experts on this subject based on the ideXlab platform.
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placental transfer of anti Group b streptococcus ImmunoGlobulin G Antibody subclasses from hiv infected and uninfected women to their uninfected infants
AIDS, 2016Co-Authors: Kirsty Le Doare, Stephen Taylor, Lauren Allen, Andrew Gorringe, Paul T Heath, Beate Kampmann, Anneke C Hesseling, Christine E JonesAbstract:Objectives: Placental Antibody transfer is impaired in the context of HIV infection, which may render HIV-exposed, uninfected infants vulnerable to Group B Streptococcus (GBS) disease. The GBS Antibody response predominately consists of ImmunoGlobulin G2 (IGG2) Antibody. Thus we determined whether concentration and placental transfer of anti-GBS Antibody subclasses was altered in HIV-infected compared with HIV-uninfected mothers. DesiGn: A retrospective analysis of anti-GBS Antibody subclasses in 38 HIV-infected and 33 HIV-uninfected mothers and their uninfected infants. Methods: Sera were analysed usinG a novel flow cytometric assay that quantified bindinG of IGG1, IGG2, IGG3 and IGG4 to serotype (ST)Ia, STIII and STV GBS bacteria. Results: IGG2 bindinG to GBS STIa and V was lower in HIV-infected women compared with HIV-uninfected women. Moreover, IGG2 bindinG to GBS STIa was also lower in HIV-exposed, uninfected infants compared with unexposed infants. However, there were no statistically siGnificant differences in the transplacental transfer ratio of IGG2 for any GBS serotype. The transplacental transfer of total IGG was reduced for GBS STIII and V and IGG1 subclass for STIII; placental transfer of all other subclasses was comparable in HIV-affected and HIV-unaffected preGnancies. Conclusion: Anti-GBS IGG2 placental transfer is not affected by HIV infection. This is important for functional Antibody aGainst the capsular polysaccharide of GBS and provides confidence that maternal GBS vaccination may result in functional activity in HIV-infected and uninfected women.
Francis Derouin - One of the best experts on this subject based on the ideXlab platform.
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lack of utility of specific ImmunoGlobulin G Antibody avidity for serodiaGnosis of reactivated toxoplasmosis in immunocompromised patients
Clinical and Vaccine Immunology, 2000Co-Authors: Benedicte Mechain, Yves J F Garin, Florence Robertgangneux, J Dupouycamet, Francis DerouinAbstract:The avidities of Toxoplasma-specific ImmunoGlobulin G serum antibodies were measured in immunocompromised patients presentinG with cerebral or extracerebral toxoplasmosis and/or seroloGical reactivation. Since avidity remained hiGh and stable in 39 of 40 patients with toxoplasmosis and 27 of 28 patients with seroloGical reactivation, we conclude that this test cannot help diaGnose toxoplasmosis in these patients.
K. Hedman - One of the best experts on this subject based on the ideXlab platform.
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ImmunoGlobulin G Antibody Avidity inPatients withRespiratory Syncytial VirusInfection
1992Co-Authors: O. Meurman, Matti Waris, K. HedmanAbstract:respiratory syncytial virusinfection. An enzyme immunoassay methodbased on theability ofureatodissociate theboundantibodies withlowavidity fromthe antiGen was used. Threepatterns ofimmuneresponseswere observed. Children 24monthsofaGehadhiGh-avidity antibodies already intheacute-phase serum samples. We conclude thattheformer children were experiencinG primary infections withrespiratory syncytial virus andthelatter wereexperiencinG reinfections. Alladults with remoteimmunity hadantibodies withhiGhavidity. DurinG an acuteinfection, thematuration ofimmune responseischaracterized bybothquantitative andqualitativechanGes inspecific antibodies. Thelatter include, e.G., chanGes intheImmunoGlobulin classdistribution andthe affinity oftheantibodies (i.e., thestrenGth oftheAntibodyantiGen bond). Affinity or,incase ofmultivalent antiGens, Antibody avidity previously couldonlybe measuredby laborious competition techniques (seereference 29)or by mathematical analysis ofenzyme immunoassay titration curves (17). Recently, simpleimmunoassays to measure Antibody avidity havebeenpublished. Protein-denaturinG aGents(e.G., diethylamine, isothiocyanate, andurea) are either included intheserum diluents toprevent thebindinG oflow-avidity antibodies (13,28)or usedinthewashinG buffer toelute theboundlow-avidity antibodies fromthe antiGen (3,10,15,27). Withthese methods, avidity measurementhasfoundimportant applications inthediaGnosis of several infections, includinG rubella andtoxoplasmosis and varicella-zoster virus infection (9,10,15,28). Respiratory syncytial virus(RSV)isthemostimportant pathoGen causinG severelowerrespiratory tractinfections in infants andsmall children (1). Itsspecial features include the incomplete protection ofinfants bymaternal antibodies, frequent reinfections, andthepossible roleofantibodies in thepathoGenesis ofthedisease. Inthisstudy, we have analyzed theimmuneresponseafter acuteRSV infection withrespect toAntibody titer andavidity.
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ImmunoGlobulin G Antibody avidity in patients with respiratory syncytial virus infection.
Journal of clinical microbiology, 1992Co-Authors: O. Meurman, Matti Waris, K. HedmanAbstract:The titer and avidity of respiratory syncytial virus-specific antibodies were measured in 196 serum specimens from 93 children with an acute, laboratory-confirmed respiratory syncytial virus infection. An enzyme immunoassay method based on the ability of urea to dissociate the bound antibodies with low avidity from the antiGen was used. Three patterns of immune responses were observed. Children less than 6 months of aGe usually had low titers of antibodies with hiGh avidity in their acute-phase serum samples. These antibodies were concluded to be of maternal oriGin, since their reaction pattern was similar to that of healthy adults. DurinG the next few weeks, a sliGht increase in titers with a concurrent decrease in Antibody avidity was observed. All children 6 to 24 months of aGe had low-avidity antibodies in their acute-phase serum samples, which matured to hiGh avidity durinG the follow-up. On the contrary, about half of the children Greater than 24 months of aGe had hiGh-avidity antibodies already in the acute-phase serum samples. We conclude that the former children were experiencinG primary infections with respiratory syncytial virus and the latter were experiencinG reinfections. All adults with remote immunity had antibodies with hiGh avidity.
Kirsty Le Doare - One of the best experts on this subject based on the ideXlab platform.
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placental transfer of anti Group b streptococcus ImmunoGlobulin G Antibody subclasses from hiv infected and uninfected women to their uninfected infants
AIDS, 2016Co-Authors: Kirsty Le Doare, Stephen Taylor, Lauren Allen, Andrew Gorringe, Paul T Heath, Beate Kampmann, Anneke C Hesseling, Christine E JonesAbstract:Objectives: Placental Antibody transfer is impaired in the context of HIV infection, which may render HIV-exposed, uninfected infants vulnerable to Group B Streptococcus (GBS) disease. The GBS Antibody response predominately consists of ImmunoGlobulin G2 (IGG2) Antibody. Thus we determined whether concentration and placental transfer of anti-GBS Antibody subclasses was altered in HIV-infected compared with HIV-uninfected mothers. DesiGn: A retrospective analysis of anti-GBS Antibody subclasses in 38 HIV-infected and 33 HIV-uninfected mothers and their uninfected infants. Methods: Sera were analysed usinG a novel flow cytometric assay that quantified bindinG of IGG1, IGG2, IGG3 and IGG4 to serotype (ST)Ia, STIII and STV GBS bacteria. Results: IGG2 bindinG to GBS STIa and V was lower in HIV-infected women compared with HIV-uninfected women. Moreover, IGG2 bindinG to GBS STIa was also lower in HIV-exposed, uninfected infants compared with unexposed infants. However, there were no statistically siGnificant differences in the transplacental transfer ratio of IGG2 for any GBS serotype. The transplacental transfer of total IGG was reduced for GBS STIII and V and IGG1 subclass for STIII; placental transfer of all other subclasses was comparable in HIV-affected and HIV-unaffected preGnancies. Conclusion: Anti-GBS IGG2 placental transfer is not affected by HIV infection. This is important for functional Antibody aGainst the capsular polysaccharide of GBS and provides confidence that maternal GBS vaccination may result in functional activity in HIV-infected and uninfected women.
