The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform

Peter Arend - One of the best experts on this subject based on the ideXlab platform.

  • Why BlOOd GrOup A Individuals Are at Risk Whereas BlOOd GrOup O Individuals Might Be PrOtected frOm SARS-COV-2 (COVID-19) InfectiOn: A HypOthesis Regarding HOw the Virus Invades the Human BOdy via AbO(H) BlOOd GrOup-Determining CarbOhydrates
    2020
    Co-Authors: Peter Arend
    Abstract:

    While the angiOtensin cOnverting enzyme 2 (ACE2) prOtein is defined as the primary severe acute respiratOry syndrOme cOrOnavirus 2 (SARS-COV-2) receptOr, the viral serine mOlecule might be mObilized by the hOst's transmembrane prOtease serine subtype 2 (TMPRSS2) enzyme frOm the viral spike (S) prOtein and hijack the hOst&rsquO;s N-acetyl-D-galactOsamine (GalNAc) metabOlism. The resulting hybrid, serOlOgically A-like/Tn (T-nOuvelle) structure pOtentially acts as a hOst–pathOgen functiOnal mOlecular bridge. In humans, this intermediate structure will hypOthetically be replaced by ABO(H) BlOOd GrOup-specific, mucin-type structures, in the case Of infectiOn hybrid epitOpes, implicating the phenOtypically glycOsidic accOmmOdatiOn Of plasma prOteins. The virus may, by mimicking the synthetic pathways Of the ABO(H) BlOOd GrOups, bind tO the cell surfaces Of the BlOOd GrOup O(H) by fOrmatiOn Of a hybrid H-type antigen as the pOtential precursOr Of hybrid nOn-O BlOOd GrOups, which dOes nOt affect the highly anti-glycan aggressive anti-A and anti-B isOagglutinin activities, exerted by the germline-encOded nOnimmune immunOglObulin M (IgM). In the nOn-O BlOOd GrOups, which have develOped frOm the H-type antigen, these IgM activities are dOwnregulated by phenOtypic glycOsylatiOn, while adaptive immunOglObulins might arise in respOnse tO the hybrid A and B BlOOd GrOup structures, bOnds between autOlOgOus carbOhydrates and fOreign peptides, suggesting the exertiOn Of autOreactivity. The nOn-O BlOOd GrOups thus becOme a preferred target fOr the virus, whereas BlOOd GrOup O(H) individuals, lacking the A/B phenOtype-determining enzymes and binding the virus alOne by hybrid H-type antigen fOrmatiOn, have the least mOlecular cOntact with the virus and maintain the critical anti-A and anti-B isOagglutinin activities, exerted by the ancestral IgM, which is cOnsidered the humOral spearhead Of innate immunity.

  • Why BlOOd GrOup A individuals are at risk whereas BlOOd GrOup O individuals are prOtected frOm SARS-COV-2 (COVID-19) infectiOn: A hypOthesis regarding hOw the virus invades the human bOdy via ABO(H) BlOOd GrOup-determining carbOhydrates
    Immunobiology, 2020
    Co-Authors: Peter Arend
    Abstract:

    Abstract While the angiOtensin cOnverting enzyme 2 (ACE2) prOtein is defined as the primary severe acute respiratOry syndrOme cOrOnavirus 2 (SARS-COV-2) receptOr, the viral serine mOlecule might be mObilized by the hOst's transmembrane prOtease serine subtype 2 (TMPRSS2) enzyme frOm the viral spike (S) prOtein and hijack the hOst’s N-acetyl-D-galactOsamine (GalNAc) metabOlism. The resulting hybrid, serOlOgically A-like/Tn (T-nOuvelle) structure pOtentially acts as a hOst–pathOgen functiOnal mOlecular bridge. In humans, this intermediate structure will hypOthetically be replaced by ABO(H) BlOOd GrOup-specific, mucin-type structures, in the case Of infectiOn hybrid epitOpes, implicating the phenOtypically glycOsidic accOmmOdatiOn Of plasma prOteins. The virus may, by mimicking the synthetic pathways Of the ABO(H) BlOOd GrOups, bind tO the cell surfaces Of the BlOOd GrOup O(H) by fOrmatiOn Of a hybrid H-type antigen as the pOtential precursOr Of hybrid nOn-O BlOOd GrOups, which dOes nOt affect the highly anti-glycan aggressive anti-A and anti-B isOagglutinin activities, exerted by the germline-encOded nOnimmune immunOglObulin M (IgM). In the nOn-O BlOOd GrOups, which have develOped frOm the H-type antigen, these IgM activities are dOwnregulated by phenOtypic glycOsylatiOn, while adaptive immunOglObulins might arise in respOnse tO the hybrid A and B BlOOd GrOup structures, bOnds between autOlOgOus carbOhydrates and fOreign peptides, suggesting the exertiOn Of autOreactivity. The nOn-O BlOOd GrOups thus becOme a preferred target fOr the virus, whereas BlOOd GrOup O(H) individuals, lacking the A/B phenOtype-determining enzymes and binding the virus alOne by hybrid H-type antigen fOrmatiOn, have the least mOlecular cOntact with the virus and maintain the critical anti-A and anti-B isOagglutinin activities, exerted by the ancestral IgM, which is cOnsidered the humOral spearhead Of innate immunity.

  • PrOpOsed O-GalNAc/Gal GlycOsylatiOn Pathways in BlOOd GrOup O and NOn-O BlOOd GrOups during PlasmOdium falciparum InfectiOns
    2020
    Co-Authors: Peter Arend
    Abstract:

    The cOevOlutiOn Of species drives diversity in animals and plants and cOntributes tO natural selectiOn, while in hOst–parasite cOevOlutiOn, a parasite may cOmplete an incOmplete evOlutiOnary/develOpmental functiOn by utilizing the hOst cell&rsquO;s machinery. Analysis Of related Older data suggests that PlasmOdium falciparum (P. falciparum), the pathOgen Of malaria trOpica, cannOt survive Outside its human hOst because it is unable tO perfOrm the evOlutiOnarily first prOtein glycOsylatiOn Or BlOOd GrOup-independent (serOlOgically A-like) O-GalNAcα1-Ser/Thr-R, Tn antigen (&ldquO;T nOuvelle&rdquO;) fOrmatiOn Owing tO its inability fOr synthesizing the aminO sugar N-acetyl-d-galactOsamine (GalNAc). This parasite breaks the species barrier via hijacking the hOst's A-like/Tn fOrmatiOn by abundantly expressing serine residues and creating hybrid A-like/Tn structures. In the human BlOOd GrOup O(H), these hybrid structures are attacked by the germline-encOded nOnimmune pOlyreactive immunOglObulin M (IgM), which physiOlOgically regulates the expressiOn Of the syngeneic A-like/Tn antigen. In nOn-O BlOOd GrOups, this antibOdy mOlecule has undergOne the phenOtypic accOmmOdatiOn Of plasma prOteins, which results in lOss Of BlOOd GrOup A- and B-cOrrespOnding anti-A and anti-B isOagglutinin activities. This lOss allOws the generatiOn Of human A- and B allele-cOnnected hybrid epitOpes and the develOpment Of life-threatening disease almOst exclusively in nOn-O BlOOd GrOups. AlthOugh malaria infectiOn Occurs regardless Of the BlOOd GrOup, the synthesis Of the BlOOd GrOup AB enables the strOngest cOntact with the pathOgen, and mOlecularly precluding any isOagglutinin activity makes this GrOup the least prOtected and the smallest amOng the ABO BlOOd GrOups. In cOntrast, BlOOd GrOup O(H) individuals have the least cOntact with the pathOgen; they maintain the isOagglutinins, rarely develOp severe disease, and survive this cOevOlutiOn in an immunOlOgical balance with the pathOgen as the largest BlOOd GrOup wOrldwide.

  • Why BlOOd GrOup A Individuals Are at Risk Whereas BlOOd GrOup O Individuals Might Be PrOtected frOm SARS-COV-2 (COVID-19) InfectiOn: A HypOthesis Regarding HOw the Virus Invades the Human BOdy via AbO(H) BlOOd GrOup-Determining CarbOhydrates
    2020
    Co-Authors: Peter Arend
    Abstract:

    While the angiOtensin cOnverting enzyme 2 (ACE2) prOtein is defined as the primary severe acute respiratOry syndrOme cOrOnavirus 2 (SARS-COV-2) receptOr, the viral serine mOlecule might be mObilized by the hOst's transmembrane prOtease serine subtype 2 (TMPRSS2) enzyme frOm the viral spike (S) prOtein and hijack the hOst&rsquO;s N-acetyl-D-galactOsamine (GalNAc) metabOlism. The resulting hybrid, serOlOgically A-like/Tn (T-nOuvelle) structure pOtentially acts as a hOst–pathOgen functiOnal mOlecular bridge. In humans, this intermediate structure will hypOthetically be replaced by ABO(H) BlOOd GrOup-specific, mucin-type structures, in the case Of infectiOn hybrid epitOpes, implicating the phenOtypically glycOsidic accOmmOdatiOn Of plasma prOteins. The virus may, by mimicking the synthetic pathways Of the ABO(H) BlOOd GrOups, bind tO the cell surfaces Of the BlOOd GrOup O(H) by fOrmatiOn Of a hybrid H-type antigen as the pOtential precursOr Of hybrid nOn-O BlOOd GrOups, which dOes nOt affect the highly anti-glycan aggressive anti-A and anti-B isOagglutinin activities, exerted by the germline-encOded nOnimmune immunOglObulin M (IgM). In the nOn-O BlOOd GrOups, which have develOped frOm the H-type antigen, these IgM activities are dOwnregulated by phenOtypic glycOsylatiOn, while adaptive immunOglObulins might arise in respOnse tO the hybrid A and B BlOOd GrOup structures, suggesting the exertiOn Of autOreactivity. The nOn-O BlOOd GrOups thus becOme a preferred target fOr the virus, whereas BlOOd GrOup O(H) individuals, lacking the A/B phenOtype-determining enzymes and binding the virus alOne by hybrid H-type antigen fOrmatiOn, have the least mOlecular cOntact with the virus and maintain the critical anti-A and anti-B isOagglutinin activities, exerted by the ancestral IgM, which is cOnsidered the humOral spearhead Of innate immunity.

  • pOsitiOn Of human BlOOd GrOup O h and phenOtype determining enzymes in grOwth and infectiOus disease
    Annals of the New York Academy of Sciences, 2018
    Co-Authors: Peter Arend
    Abstract:

    The human ABO(H) BlOOd GrOup phenOtypes arise frOm the evOlutiOnarily Oldest genetic system fOund in primate pOpulatiOns. While the BlOOd GrOup antigen A is cOnsidered the ancestral primOrdial structure, under the selective pressure Of life-threatening diseases BlOOd GrOup O(H) came tO dOminate as the mOst frequently Occurring BlOOd GrOup wOrldwide. NOn-O(H) phenOtypes demOnstrate impaired fOrmatiOn Of adaptive and innate immunOglObulin specificities due tO clOnal selectiOn and phenOtype fOrmatiOn in plasma prOteins. COmpared with individuals with BlOOd GrOup O(H), BlOOd GrOup A individuals nOt Only have a significantly higher risk Of develOping certain types Of cancer but alsO exhibit high susceptibility tO malaria trOpica Or infectiOn by PlasmOdium falciparum. The phenOtype-determining BlOOd GrOup A glycOtransferase(s), which affect the levels Of anti-A/Tn crOss-reactive immunOglObulins in phenOtypic glycOsidic accOmmOdatiOn, might alsO mediate adhesiOn and entry Of the parasite tO hOst cells via trans-species O-GalNAc glycOsylatiOn Of abundantly expressed serine residues that arise thrOughOut the parasite's life cycle, while excluding the pOssibility Of antibOdy fOrmatiOn against the resulting hybrid Tn antigen. In cOntrast, human BlOOd GrOup O(H), lacking this enzyme, is indicated tO cOnfer a survival advantage regarding the Overall risk Of develOping cancer, and individuals with this BlOOd GrOup rarely develOp life-threatening infectiOns invOlving evOlutiOnarily selective malaria strains.

Bradley Mcpherson - One of the best experts on this subject based on the ideXlab platform.

  • ABO BlOOd GrOup and COchlear Status: OtOacOustic EmissiOn Markers.
    Ear and hearing, 2018
    Co-Authors: Welen Weilu Chen, Kin Tsun Chow, Bradley Mcpherson
    Abstract:

    OBJECTIVES:There are an increasing number Of research studies examining the effects Of ABO BlOOd GrOup On susceptibility tO disease. HOwever, little is knOwn regarding the pOtential relatiOnship between BlOOd GrOup and hearing. Higher risk Of nOise-induced hearing lOss was linked tO BlOOd GrOup O in several OccupatiOnal health studies. Based On this finding, a recent study Of cOchlear status was cOnducted with nOrmal-hearing female participants representing equal numbers Of the fOur BlOOd GrOups in the ABO BlOOd GrOup system. ABO BlOOd GrOup was assOciated with cOchlear characteristics, including the prevalence Of spOntaneOus OtOacOustic emissiOns (SOAEs) and the amplitudes Of transient-evOked OtOacOustic emissiOns (TEOAEs) and distOrtiOn-prOduct OtOacOustic emissiOns (DPOAEs). Females with BlOOd GrOup O shOwed significantly lOwer amplitudes Of DPOAEs at sOme frequencies and lOwer prevalence Of SOAEs cOmpared with participants with BlOOd GrOup B. There was a general trend Of reduced TEOAE and DPOAE amplitudes in BlOOd GrOup O individuals cOmpared with participants with nOn-O BlOOd GrOups. FOllOwing frOm this finding, and based On knOwn sex differences in OtOacOustic emissiOn characteristics, the present study examined the pOssible effects Of BlOOd GrOup On OtOacOustic emissiOn status in males. DESIGN:Sixty clinically nOrmal-hearing males aged between 18 and 26 years, with equal numbers Of participants in each Of the ABO BlOOd GrOups, were recruited by purpOsive sampling. SOAE, DPOAE, and linear and nOnlinear TEOAE recOrdings were cOllected frOm all participants, as well as tympanOmetric data related tO external and middle ear characteristics. RESULTS:The male BlOOd GrOup O participants exhibited significantly lOwer SOAE prevalence and reduced amplitudes Of DPOAEs On average, and in the midfrequency range, than participants with BlOOd GrOup B, and lOwer nOnlinear and linear TEOAE amplitudes at a number Of frequencies when cOmpared with participants with BlOOd GrOups A and B. A cOnsistent trend Of lOwer TEOAE and DPOAE respOnse amplitudes was Observed in participants with BlOOd GrOup O. NO significant difference was nOted amOng BlOOd GrOups fOr Outer Or middle ear characteristics. CONCLUSIONS:These results were cOnsistent with previOus findings Of reduced OtOacOustic emissiOn respOnses in female BlOOd GrOup O individuals. Results suppOrt the hypOthesis that BlOOd GrOup O individuals may be at increased risk Of cOchlear damage frOm nOise expOsure. Further investigatiOn On the pOtential link between ABO BlOOd GrOup and auditOry status, including pOtentially differential effects Of nOise expOsure On cOchlear functiOn, is needed. The pOssible effects Of ABO BlOOd GrOup On Other aspects Of auditiOn, such as hearing sensitivity, speech understanding, and auditOry prOcessing, shOuld be evaluated.

Annarita Tagliaferri - One of the best experts on this subject based on the ideXlab platform.

  • BlOOd GrOup O prOtects against inhibitOr develOpment in severe hemOphilia a patients
    Seminars in Thrombosis and Hemostasis, 2016
    Co-Authors: Massimo Franchini, Antonio Coppola, Carlo Mengoli, Gianna Franca Rivolta, Federica Riccardi, Giovanni Di Minno, Annarita Tagliaferri
    Abstract:

    Increasing evidence suppOrts the link between ABO(H) BlOOd GrOup determinants and hemOstasis. In particular, the ABO-related different glycOsylatiOn patterns Of vOn Willebrand factOr strOngly influence its clearance and functiOnal levels, and this may cOntribute tO the inter-individual variatiOns in the half-life Of infused FactOr VIII (FVIII) in hemOphilia A (HA) patients. We investigated the rOle Of ABO BlOOd GrOups in regulating FVIII immunOgenicity by evaluating their distributiOn in patients with severe (FVIII < 1 IU/dL) HA accOrding tO inhibitOr develOpment and Other knOwn relevant factOrs. In a cOhOrt Of Italian severe HA patients (n = 209), the ABO BlOOd GrOup distributiOn was similar tO that in the healthy general pOpulatiOn. HOwever, the distributiOn Of inhibitOrs, develOped in 56 patients Overall (26.8%), was significantly different in the fOur ABO phenOtypes (O, 18.2%; A, 31.9%; B, 39.1%, AB, 25%; p = 0.033); this difference seemed mOre prOnOunced when Only high-titer inhibitOrs (Overall, 21.1%) were cOnsidered (O, 11.4%; A, 27.7%; B, 34.8%; p = 0.011). Relative risks in O versus nOn-O BlOOd GrOup were 0.55 (95% CI: 0.33-0.92) and 0.40 (95% CI: 0.21-0.77) fOr any and high-titer inhibitOrs, respectively. In a multivariate lOgistic regressiOn, O BlOOd GrOup was shOwn tO lOwer (apprOximately twOfOld) inhibitOr risk, similarly with plasma-derived FVIII, whereas high-risk F8 mutatiOns were assOciated with increased risk. HOwever, the estimated effect Of O BlOOd type On inhibitOr develOpment was free frOm any significant cOrrelatiOn tO Other cOvariates, including presence Of high-risk F8 mutatiOns and type Of replacement FVIII used. In this retrOspective cOhOrt Of severe hemOphiliacs, BlOOd GrOup O appears tO prOtect against inhibitOr develOpment, with independent effects frOm Other cOvariates. Larger prOspective studies are needed tO cOnfirm this finding and tO delve deeper intO its pathOphysiOlOgic mechanisms.

  • BlOOd GrOup O PrOtects against InhibitOr DevelOpment in Severe HemOphilia A Patients.
    Seminars in thrombosis and hemostasis, 2016
    Co-Authors: Massimo Franchini, Antonio Coppola, Carlo Mengoli, Gianna Franca Rivolta, Federica Riccardi, Giovanni Di Minno, Annarita Tagliaferri
    Abstract:

    Increasing evidence suppOrts the link between ABO(H) BlOOd GrOup determinants and hemOstasis. In particular, the ABO-related different glycOsylatiOn patterns Of vOn Willebrand factOr strOngly influence its clearance and functiOnal levels, and this may cOntribute tO the inter-individual variatiOns in the half-life Of infused FactOr VIII (FVIII) in hemOphilia A (HA) patients. We investigated the rOle Of ABO BlOOd GrOups in regulating FVIII immunOgenicity by evaluating their distributiOn in patients with severe (FVIII 

Lutz Liefeldt - One of the best experts on this subject based on the ideXlab platform.

  • the BlOOd GrOup O prOblem in kidney transplantatiOn time tO change
    Nephrology Dialysis Transplantation, 2010
    Co-Authors: Petra Glander, Klemens Budde, Danilo Schmidt, Markus Giessing, Hans-hellmut Neumayer, Florian T Fuller, Lutz Liefeldt
    Abstract:

    BackgrOund. Patients with BlOOd GrOup O have disadvantages in the allOcatiOn Of deceased dOnOr Organs in the EurOtransplant Kidney AllOcatiOn System and fewer ABO-cOmpatible living dOnOrs. In Order tO investigate the cOnsequences Of this dilemma, we analysed the OutcOme Of patients with BlOOd GrOup O in Our transplantatiOn prOgramme. MethOds. A single-centre analysis Of 1186 waitlisted patients fOr first deceased dOnOr kidney transplantatiOns between 1996 and 2008 was perfOrmed, and the mechanisms Of BlOOd GrOup-dependant differences fOr graft and recipient OutcOme were assessed. Results. Median fOllOw-up time until death Or end Of ObservatiOn fOr all waitlisted patients was 66 mOnths (range, 0–158 mOnths) and fOr 589 recipients Of a kidney graft was 61 mOnths (range, 0–158 mOnths). Patients with BlOOd GrOup O had significantly lOnger waiting times fOr deceased dOnOr kidney grafts, cOmpared tO nOn-GrOup O recipients (median waiting time, 85 vs 59 mOnths). As a cOnsequence, BlOOd GrOup O patients had an increased risk fOr death withOut transplantatiOn (13.1% fOr O patients vs 9.6% fOr nOn-O patients; P < 0.05). Despite a gOOd human leukOcyte antigen match, graft OutcOme tended tO be wOrse in O recipients; 14.1% (95% CI, 8.2– 19.9%) Of all O kidneys frOm deceased dOnOrs were transplanted intO nOn-O recipients, leading tO the accumulatiOn Of O recipients On the waiting list. COnclusiOns. The expOrt Of BlOOd GrOup O dOnOr kidneys tO Other BlOOd GrOups leads tO lOnger waiting times, tO a higher death rate and tO accumulatiOn Of BlOOd GrOup O patients On the waiting list, which will further aggravate the prOblem in the future. Our results shOuld prOmpt further research On the issues assOciated with BlOOd GrOup O. Current allOcatiOn systems and living dOnOr kidney exchange prOgrammes shOuld be re-evaluated tO address this prOblem.

  • The ‘BlOOd GrOup O prOblem’ in kidney transplantatiOn—time tO change?
    Nephrology dialysis transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 2010
    Co-Authors: Petra Glander, Klemens Budde, Danilo Schmidt, T. Florian Fuller, Markus Giessing, Hans-hellmut Neumayer, Lutz Liefeldt
    Abstract:

    BackgrOund. Patients with BlOOd GrOup O have disadvantages in the allOcatiOn Of deceased dOnOr Organs in the EurOtransplant Kidney AllOcatiOn System and fewer ABO-cOmpatible living dOnOrs. In Order tO investigate the cOnsequences Of this dilemma, we analysed the OutcOme Of patients with BlOOd GrOup O in Our transplantatiOn prOgramme. MethOds. A single-centre analysis Of 1186 waitlisted patients fOr first deceased dOnOr kidney transplantatiOns between 1996 and 2008 was perfOrmed, and the mechanisms Of BlOOd GrOup-dependant differences fOr graft and recipient OutcOme were assessed. Results. Median fOllOw-up time until death Or end Of ObservatiOn fOr all waitlisted patients was 66 mOnths (range, 0–158 mOnths) and fOr 589 recipients Of a kidney graft was 61 mOnths (range, 0–158 mOnths). Patients with BlOOd GrOup O had significantly lOnger waiting times fOr deceased dOnOr kidney grafts, cOmpared tO nOn-GrOup O recipients (median waiting time, 85 vs 59 mOnths). As a cOnsequence, BlOOd GrOup O patients had an increased risk fOr death withOut transplantatiOn (13.1% fOr O patients vs 9.6% fOr nOn-O patients; P < 0.05). Despite a gOOd human leukOcyte antigen match, graft OutcOme tended tO be wOrse in O recipients; 14.1% (95% CI, 8.2– 19.9%) Of all O kidneys frOm deceased dOnOrs were transplanted intO nOn-O recipients, leading tO the accumulatiOn Of O recipients On the waiting list. COnclusiOns. The expOrt Of BlOOd GrOup O dOnOr kidneys tO Other BlOOd GrOups leads tO lOnger waiting times, tO a higher death rate and tO accumulatiOn Of BlOOd GrOup O patients On the waiting list, which will further aggravate the prOblem in the future. Our results shOuld prOmpt further research On the issues assOciated with BlOOd GrOup O. Current allOcatiOn systems and living dOnOr kidney exchange prOgrammes shOuld be re-evaluated tO address this prOblem.

Sara K. Vesely - One of the best experts on this subject based on the ideXlab platform.