Associations between Three Types of Maternal Bacterial Infection and Risk of Leukemia in the Offspring

Abstract

A case-control study was nested within two maternity cohorts with a total of 7 million years of follow-up for assessment of the role of bacterial infections in childhood leukemia. Offspring of 550,000 mothers in Finland and Iceland were combined to form a joint cohort that was followed for cancer up to age 15 years during 1975-1997 through national cancer registries. For each index mother-case pair, three or four matched control mother-control pairs were identified from population registers. First-trimester serum samples were retrieved from mothers of 341 acute lymphoblastic leukemia cases and 61 other leukemia cases and from 1,212 control mothers. Sera were tested for antibodies to the genus Chlamydia, Helicobacter pylori, and Mycoplasma pneumoniae. Odds ratios and 95% confidence intervals, adjusted for sibship size, were calculated as estimates of relative risk. M. pneumoniae immunoglobulin M appeared to be associated with increased risk (odds ratio (OR) = 1.6), but the association lost statistical significance when the specificity of the immunoglobulin M was considered (OR = 1.5, 95% confidence interval: 0.9, 2.4). In Iceland, H. pylori immunoglobulin G was associated with increased risk of childhood leukemia in offspring (OR = 2.8, 95% confidence interval: 1.1, 6.9). Since H. pylori immunoglobulin G indicates chronic carriage of the microorganism, early colonization of the offspring probably differs between Iceland and Finland, two affluent countries.

Number of Siblings and the Risk of Lymphoma, Leukemia, and Myeloma by Histopathology

“…However, our results suggest that a good candidate would be an infection that runs in families. Infections with Mycoplasma pneumonie (42,43) and more recently, with Helicobacter pylori, both pathogens that have been reported to be transmitted within families and from mother to child, have been reported to be associated with adult ALL (44). Specific agents associated with acute myeloid leukemia include human herpes virus 6 (24,25) and, possibly, varicella zoster for acute monocytic leukemia (26).…”

Role of Bacteria in Oncogenesis

“…Other associations between bacterial infection and B-cell proliferation have been examined in a few studies. Among these, H. pylori seropositivity in childbearing women has been linked with childhood acute lymphocytic leukemia in their offspring (147), and Chlamydia pneumonia has been associated with lung MALT lymphoma (44) and the Séz-ary syndrome (5). However, the lack of sufficient data precludes any conclusions about these associations at this time.…”

Annual report to the nation on the status of cancer, 1975–2003, featuring cancer among U.S. Hispanic/Latino populations

“…Variation in possible etiologic factors for childhood leukemias, such as paternal smoking, occupational exposure to benzene, household solvents, home use of pesticides, radiation, maternal diet, child's diet, infection, and genetic susceptibility have been investigated with inconsistent results. 85,[94][95][96][97] For Hodgkin lymphoma, incidence is low in children and high in adolescents and young adults in developed countries, while in developing countries, rates are high in childhood, then low until old age. 93 Age-related differences in histological subtypes have been observed.…”