Chang et al. Respond to "Allergies and ALL: Biology or Bias?"

[[abstract]]We thank Drs. Linabery and Spector for their commentary (1) on our analysis of the association between allergies and childhood acute lymphoblastic leukemia (ALL) (2). We appreciate their thorough presentation of the potential biases that may occur in epidemiologic studies examining the association between allergies and childhood leukemia, possible biologic mechanisms linking allergies to childhood leukemia, and suggestions for future research. In a case-control study, it is always a challenge to obtain an accurate exposure history, especially in studies that rely on self-reported data. As noted by Linabery and Spector, children's histories of allergies supplied via parental reports can be subject to selection and recall biases and misclassification. Although information on allergies obtained from medical records is less likely to be subject to differential misclassification due to the differential recall between case and control parents, these