title: Breastfeeding and early infection in the aetiology of childhood leukaemia in Down syndrome.
abstract: BACKGROUND
  For a child to develop acute leukaemia (AL), environmental exposure may not be sufficient: interaction with a susceptibility factor to the disease, such as Down syndrome (DS), may also be necessary. We assessed whether breastfeeding and early infection were associated with the risk of developing AL in children with DS.
  
  
  METHODS
  Children with DS in Mexico City, and either with or without AL, were the cases (N=57) and controls (N=218), respectively. Population was divided in children with AL and with acute lymphoblastic leukaemia (ALL) and also in children < or = 6 and >6 years old.
  
  
  RESULTS
  Breastfeeding and early infections showed moderate (but not significant) association for AL, whereas hospitalisation by infection during the first year of life increased the risk: odds ratios (confidence interval 95%) were 0.84 (0.43-1.61), 1.70 (0.82-3.52); and 3.57 (1.59-8.05), respectively. A similar result was obtained when only ALL was analysed.
  
  
  CONCLUSIONS
  We found that breastfeeding was a protective factor for developing AL and ALL, and during the first year of life, infections requiring hospitalisation were related to a risk for developing the disease in those children with DS >6 years of age. These data do not support the Greaves's hypothesis of early infection being protective for developing ALL.
authors.affiliation: Unidad de Investigacion en Epidemiologia Clinica, Hospital de Pediatria, Centro Medico Nacional Siglo XXI (IMSS), Quetzal 27, Las Arboledas, 52950 Mexico DF, Mexico.
authors.forename: J
authors.initials: J
authors.lastname: Flores-Lujano
authors.forename: M L
authors.initials: ML
authors.lastname: Perez-Saldivar
authors.forename: E M
authors.initials: EM
authors.lastname: Fuentes-Pananá
authors.forename: C
authors.initials: C
authors.lastname: Gorodezky
authors.forename: R
authors.initials: R
authors.lastname: Bernaldez-Rios
authors.forename: M A
authors.initials: MA
authors.lastname: Del Campo-Martinez
authors.forename: A
authors.initials: A
authors.lastname: Martinez-Avalos
authors.forename: A
authors.initials: A
authors.lastname: Medina-Sanson
authors.forename: R
authors.initials: R
authors.lastname: Paredes-Aguilera
authors.forename: J
authors.initials: J
authors.lastname: De Diego-Flores Chapa
authors.forename: V
authors.initials: V
authors.lastname: Bolea-Murga
authors.forename: M C
authors.initials: MC
authors.lastname: Rodriguez-Zepeda
authors.forename: R
authors.initials: R
authors.lastname: Rivera-Luna
authors.forename: M A
authors.initials: MA
authors.lastname: Palomo-Colli
authors.forename: L
authors.initials: L
authors.lastname: Romero-Guzman
authors.forename: P
authors.initials: P
authors.lastname: Perez-Vera
authors.forename: M
authors.initials: M
authors.lastname: Alvarado-Ibarra
authors.forename: F
authors.initials: F
authors.lastname: Salamanca-Gómez
authors.forename: A
authors.initials: A
authors.lastname: Fajardo-Gutierrez
authors.forename: J M
authors.initials: JM
authors.lastname: Mejía-Aranguré
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D001942:Breast Feeding / Q000009:adverse effects*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004314:Down Syndrome / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007239:Infections / Q000150:complications* / Q000453:epidemiology*; D007951:Leukemia, Myeloid / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D016017:Odds Ratio; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology*; D012044:Regression Analysis; D011795:Surveys and Questionnaires
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