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Correspondence
Verticaltransmissionofantibodiesininfants
bornfrommotherswithpositiveserologyto
COVID-19pneumonia
DearEditor,
Thereisstillmuchunknownregardingtheimpactofthedisease
onpregnancy.ThemajorityofreportedcasesofCOVID-19infection
inpregnantpatientshaveshownamildorasymptomaticcourseof
thedisease,withonlyfewcasesrequiringintensivecareunit(ICU)
admission, andonly a fewreportedcases requiringmechanical
ventilation1.
Todatethereisnocertaintyifthemothertransmitsserological
protectionthroughtheplacenta.Wedescribetwocasesofmother
withpositiveIGGonperiphericalbloodtest,andtheevidenceIGG
testingpositiveinumbilicalcordsoonafterdelivery.
Serum samples were tested for Sars-CoV-2 antibodies by
using a chemiluminescent microparticle immunoassay (CMIA)
intendedforthequalitativedetectionofIgGantibodiesto
SARS-CoV-2 in human serum. Patient samples were runned on an
automated chemiluminescence analyzer (Architect Abbott) for
thedetectionofspecificserumIgGandIgMinresponseto
SARS-CoV-2 recent or prior infection2. Positivity to Covid-19 was
establishedbythereal-timepolymerasechainreaction(RT-PCR)
onnasopharyngealswab.
ThefirstpatientSJwasadmittedinourcliniconMay15th2020,
resultingpositivetonasopharyngealswabandserologyforCovid
19IGG(Index7.20).ShewasasymptomaticforCovid19,without
fever, cough, and dyspnea and diarrhea. At the admission she
resultedpositivetotheserologyforCovid19IGG(Index7.20)and
thereal-timepolymerasechainreaction(RT-PCR)on
nasopharyn-gealswabwaspositivetoo.Sheunderwentcesareansectiondueto
initiallabor at 37 weeks and polidramnios in double previous
cesareansection.ThebabywasadmittedinNICUbecauseofthe
onset of mild respiratory distress after 30 minutes. Serological
testingonumbilicalcordandperipheralbloodwerepositivefor
Covid19IGG(index7.03).NasopharyngealswabRT-PCRresulted
negativeforCovid 19.The babywas dismissedafter10daysof
oxygenandantibiotictherapy,andherfollowuphasbeensofar
negative.
ThesecondpatientGPwasadmittedinourcliniconJunethe
2nd 2020, resulting positive tothe serology for Covid 19 IGG
(index 8,01) but negative on naso-pharyngeal swab. She was
asymptomatic forCovid19,without fever,cough,dyspnea and
diarrhea.Herobstetrical historywasuncomplicated. She
deliv-ered spontaneously after amniotic rupture. During the birth
serological testingonumbilical cord,amnioticfluidandbaby’s
peripheralbloodwasperformed,andtheyresulted positivefor
Covid19IGG(index7.66).
InourcasesSARS-CoV-19 IgGweredetected inthematernal
serum, andspecificantibodiesweredetected inneonatalblood
serum sampleswithelevated concentrations,similartotheIgG
concentrations of their respective mothers,despite the babies’
throatswabwerenegative.
IgGispassivelytransferredacrosstheplacentafrommotherto
fetus,beginning attheendof thesecondtrimesterandreaches
high levels at the time of birth 3, while IgM is not usually
transferredfrommothertofetusbecauseofitslarger
macromo-lecularstructure.
Somestudieshavebeenpublisheddemonstratingthepresence
ofIgMinthenewborn,suggestingthatthebabyhaddevelopedthe
intrauterineinfectionandhehadproducedtheIgMautonomously.
Thehumanfetuseshasbeenfoundcapabletoproduce
immuno-globulinesbuthalflifeofIgMisfivedays4.
ThesefindingsupdatethecaseseriespublishedbyZeng5adding
twocasesWeunderlinetheneedoffurtherstudiestodeepenthe
serological characteristics of infants whose mothers had been
infectedwithSARS-CoV-2,andtheirimmunitytothevirus.
References
[1]ChenH,GuoJ,WangC,etal.Clinicalcharacteristicsandintrauterinevertical transmission potentialof COVID-19 infectionin nine pregnantwomen: a retrospectivereviewofmedicalrecords.TheLancet2020;395(10226):809–15, doi:http://dx.doi.org/10.1016/S0140-6736(20)30360-3.
[2]BryanA,PepperG,WenerMH,etal.PerformancecharacteristicsoftheAbbott architectSARS-CoV-2IgGAssayandSeroprevalenceinBoiseIdaho.,doi:http:// dx.doi.org/10.1128/JCM.00941-20.
[3]Kohler PF,Farr RS.Elevation ofCordover MaternalIgGImmunoglobulin: EvidenceforanActivePlacentalIgGTransport.Nature1966;210(5040):1070–1, doi:http://dx.doi.org/10.1038/2101070a0.
[4]HaiderSA.SerumIgMinDiagnosisofInfectionintheNewborn.ArchDisChild 1972;47(253):382–93,doi:http://dx.doi.org/10.1136/adc.47.253.382. [5]ZengH,XuC,FanJ,etal.AntibodiesinInfantsBorntoMothersWithCOVID-19
Pneumonia. JAMA 2020, doi:http://dx.doi.org/10.1001/jama.2020.4861 Pub-lishedonlineMarch26.
NicolettaVendola
SCOstetriciaeGinecologia,OspedaleSant’Andrea,Vercelli,Italy
Vivianastampini
ObstetricsandGynecologyClinic,UniversityofEasternPiedmont,
Italy
https://doi.org/10.1016/j.ejogrb.2020.08.023
0301-2115/©2020ElsevierB.V.Allrightsreserved.
EuropeanJournalofObstetrics&GynecologyandReproductiveBiology253(2020)331–332
ContentslistsavailableatScienceDirect
European
Journal
of
Obstetrics
&
Gynecology
and
Reproductive
Biology
RobertaAmadori
ObstetricsandGynecologyClinic,OspedaleMaggioredellaCarità
Novara,Italy
MartinaGerbino
ObstetricsandGynecologyClinic,UniversityofEasternPiedmont,
Italy
AnnalisaCuratolo
SCOstetriciaeGinecologia,OspedaleSant’Andrea,Vercelli,Italy
Danielasurico
ObstetricsandGynecologyClinic,UniversityofEasternPiedmont,
Italy
Received4August2020
