title: Is there a correlation between anti-pig antibody levels in humans and geographic location during childhood?
abstract: BACKGROUND
  An initial observation suggested high levels of anti-pig antibodies in healthy humans who had spent their childhood in the Middle East. We tested larger cohorts to determine whether anti-pig antibody levels correlated with the geographic location in which the subject spent his/her childhood, because this might have implications for clinical trials of xenotransplantation.
  
  
  METHODS
  Anti-pig IgM and IgG levels (by flow cytometry using peripheral blood mononuclear cells from wild-type and α1,3-galactosyltransferase gene-knockout pigs) and anti-Gal IgM and IgG levels (by enzyme-linked immunosorbent assay) were measured in 75 volunteers. Comparisons of antibody levels were also made based on subject age, gender, ABO blood group, diet, and history of vaccination.
  
  
  RESULTS
  Antibody binding to α1,3-galactosyltransferase gene-knockout pig cells was less than to wild-type cells. There was a reduction in anti-pig IgM and anti-Gal IgM, but a slight increase in anti-nonGal IgG, with age. Women had higher levels of anti-Gal IgM than men. Blood group A subjects had higher levels of anti-pig IgM and IgG than those of group AB. Diet had no influence on antibody levels. Typhoid or measles-mumps-rubella vaccination was associated with lower anti-nonGal IgG or anti-Gal IgG, respectively, whereas influenza vaccination was associated with higher anti-nonGal IgG. There were some significant variations in antibody levels associated with location during childhood, with subjects from the Middle East demonstrating higher anti-nonGal IgG and anti-Gal IgG.
  
  
  CONCLUSIONS
  Clinical trials of xenotransplantation may be influenced by various factors, including the geographic location of the recipient during childhood, possibly associated with exposure to different microorganisms.
authors.affiliation: Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Goutham
authors.initials: G
authors.lastname: Kumar
authors.forename: Vikas
authors.initials: V
authors.lastname: Satyananda
authors.forename: Jason
authors.initials: J
authors.lastname: Fang
authors.forename: Hao
authors.initials: H
authors.lastname: Zhou
authors.forename: Minoru
authors.initials: M
authors.lastname: Fujita
authors.forename: Burcin
authors.initials: B
authors.lastname: Ekser
authors.forename: Cassandra
authors.initials: C
authors.lastname: Long
authors.forename: Eefje
authors.initials: E
authors.lastname: Dons
authors.forename: Qing
authors.initials: Q
authors.lastname: Sun
authors.forename: David
authors.initials: D
authors.lastname: Ayares
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Hara
authors.forename: David K C
authors.initials: DK
authors.lastname: Cooper
mesh_terms: D000017:ABO Blood-Group System; D000328:Adult; D000368:Aged; D000818:Animals; D000910:Antibodies, Heterophile / Q000097:blood; D002648:Child; D015331:Cohort Studies; D005260:Female; D005690:Galactose / Q000276:immunology; D005700:Galactosyltransferases / Q000172:deficiency / Q000235:genetics; D055786:Gene Knockout Techniques; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007963:Leukocytes, Mononuclear / Q000201:enzymology / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008877:Middle East / Q000208:ethnology; D034421:Sus scrofa / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D014481:United States; D055815:Young Adult
chemical_list: D000017:ABO Blood-Group System; D000910:Antibodies, Heterophile; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D005700:Galactosyltransferases; C047006:N-acetyllactosaminide alpha-1,3-galactosyltransferase; D005690:Galactose