title: Delivery route determines the presence of immune complexes on umbilical cord erythrocytes.
abstract: OBJECTIVE
  Umbilical cord blood offers a unique opportunity to study the basal level of immunoglobulin complexes. This study aims to determine the presence of immune complexes and complement deposition on erythrocytes from umbilical cord blood from normal, full-term pregnancies.
  
  
  METHODS
  In vitro pre-formed IgA, IgG, and IgM complexes were used as positive control for flow cytometry detection, and for C3d deposition. Blood samples (34) of umbilical cord blood taken from vaginal and cesarean deliveries were tested for the presence of immunoglobulin complexes.
  
  
  RESULTS
  Fourteen samples from vaginal deliveries and 20 samples from cesarean deliveries were assessed. IgG and IgM complexes were detected on erythrocytes, whereas no IgA complexes or complement deposition was observed. Interestingly, the percentage of IgG complexes was higher on erythrocytes from vaginal delivery samples compared to those from cesarean deliveries. No other associations between immune complexes and other maternal or newborn variables were found.
  
  
  CONCLUSIONS
  IgG and IgM complexes seem to be normally present on umbilical cord erythrocytes. Erythrocytes from vaginal deliveries have a higher percentage of IgG complexes present compared to that from cesarean deliveries. Since no C3d activity was detected, these complexes are non-pathological and should be part of the newborn's initial innate immune response.
authors.affiliation: a Grupo de Ciencias Básicas Médicas , School of Medicine, Universidad de los Andes , Bogotá D.C. , Colombia.
authors.forename: Andrés
authors.initials: A
authors.lastname: de Lima
authors.affiliation: b Department of Gynecology and Obstetrics , Hospital Universitario Fundación Santa Fe de Bogotá and School of Medicine, Universidad de los Andes , Bogotá D.C. , Colombia.
authors.forename: Luis C
authors.initials: LC
authors.lastname: Franco
authors.affiliation: b Department of Gynecology and Obstetrics , Hospital Universitario Fundación Santa Fe de Bogotá and School of Medicine, Universidad de los Andes , Bogotá D.C. , Colombia.
authors.forename: Andrés
authors.initials: A
authors.lastname: Sarmiento
authors.affiliation: a Grupo de Ciencias Básicas Médicas , School of Medicine, Universidad de los Andes , Bogotá D.C. , Colombia.
authors.forename: John M
authors.initials: JM
authors.lastname: González
mesh_terms: D000328:Adult; D000936:Antigen-Antibody Complex / Q000378:metabolism*; D001034:Apgar Score; D002585:Cesarean Section; D036861:Delivery, Obstetric / Q000379:methods*; D004912:Erythrocytes / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D005312:Fetal Blood / Q000276:immunology* / Q000378:metabolism*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D055815:Young Adult
chemical_list: D000936:Antigen-Antibody Complex
keywords: Immune complexes; complement C3d; flow cytometry; immunoglobulins; umbilical cord