title: Human leukocyte antigen concordance and the transmission risk via breast-feeding of human T cell lymphotropic virus type I.
abstract: OBJECTIVE
  We examined the association between mother-to-child human T cell lymphotropic virus type I (HTLV-I) transmission and human leukocyte antigen (HLA) class I types.
  
  
  METHODS
  In 1989, children born to HTLV-I-infected mothers in Jamaica were enrolled and prospectively evaluated for HTLV-I infection. HLA class I types in mothers and children were determined by DNA-based polymerase chain reaction methods. Associations between HLA class I types and transmission of HTLV-I were analyzed using proportional-hazards regression models adjusted for the duration of breast-feeding. Transmission risk in children still breast-feeding at 12 months was determined using actuarial methods.
  
  
  RESULTS
  Of 162 children, 28 (17%) became infected. After Bonferroni's adjustment for multiple comparisons, the transmission risk was not influenced by any specific HLA class type or the A2 supertype. However, compared with children who shared 3 HLA class I types with their mothers (the minimum number possible), the transmission risk increased 1.8-fold with 4 shared types and 3.0-fold with 5 or 6 shared types (Ptrend = .039; 1.75-fold increase for each additional concordant HLA type). This association was independent of maternal HTLV-I proviral level, antibody titer, and household income.
  
  
  CONCLUSIONS
  We found a significant dose-response relationship between HTLV-I transmission via breast-feeding and mother-child HLA class I type concordance. Immunological interactions between a child's cells and maternal cells may influence the risk of HTLV-I infection by breast-feeding, perhaps because antigens on maternal cells are seen by the child as being "self."
authors.affiliation: Viral Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20852, USA. biggarb@mail.nih.gov
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Biggar
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ng
authors.forename: Norma
authors.initials: N
authors.lastname: Kim
authors.forename: Michie
authors.initials: M
authors.lastname: Hisada
authors.forename: Hong-Chuan
authors.initials: HC
authors.lastname: Li
authors.forename: Beverley
authors.initials: B
authors.lastname: Cranston
authors.forename: Barrie
authors.initials: B
authors.lastname: Hanchard
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Maloney
mesh_terms: D001942:Breast Feeding; D002675:Child, Preschool; D005260:Female; D005805:Genes, MHC Class I; D015481:HTLV-I Antibodies / Q000097:blood; D015490:HTLV-I Infections / Q000235:genetics / Q000276:immunology* / Q000635:transmission*; D015368:Human T-lymphotropic virus 1 / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D007563:Jamaica; D011533:Proviruses / Q000302:isolation & purification; D012307:Risk Factors; D012959:Socioeconomic Factors
chemical_list: D015481:HTLV-I Antibodies