Marcotte Erin L, Ritz Beate, Cockburn Myles, Yu Fei, Heck Julia E
Authors' Affiliations: Department of Pediatrics, Division of Epidemiology and Clinical Research, University of Minnesota, Minneapolis, Minnesota; Departments of.
Epidemiology and.
Cancer Epidemiol Biomarkers Prev. 2014 Jul;23(7):1195-203. doi: 10.1158/1055-9965.EPI-13-1330. Epub 2014 May 3.
Epidemiologic studies indicate that infections in early childhood may protect against pediatric acute lymphoblastic leukemia (ALL).
We identified 3,402 ALL cases among children 0 to 5 years of age using the California Cancer Registry. From California birth records we randomly selected controls in a 20:1 ratio and frequency matched them to cases by birth year. We investigated markers of exposure to infections, including month of birth, timing of birth in relation to influenza and respiratory syncytial virus (RSV) seasons, and birth order based on data from California birth certificates and national infection surveillance systems.
We observed an increased risk of ALL for spring and summer births, and for those first exposed to an influenza or RSV season at nine to twelve months of age compared with those exposed during the first three months of life, and this association was stronger among first born children [odds ratios (OR), 1.44 and 95% confidence intervals (CI), 1.13-1.82, for influenza exposure at nine to twelve months of age]. Decreased risk was observed with increasing birth order among non-Hispanic whites but not Hispanics (OR, 0.76 and 95% CI, 0.59-096, for fourth or higher birth order among whites).
Our results support the hypothesis that infections in early childhood decrease risk of ALL.
Our findings implicate early life exposure to infections as protective factors for ALL in young children.
流行病学研究表明，幼儿期感染可能预防儿童急性淋巴细胞白血病（ALL）。
我们使用加利福尼亚癌症登记处确定了3402例0至5岁儿童的ALL病例。从加利福尼亚出生记录中，我们以20:1的比例随机选择对照，并按出生年份将他们与病例进行频率匹配。我们根据加利福尼亚出生证明和国家感染监测系统的数据，调查了感染暴露的标志物，包括出生月份、与流感和呼吸道合胞病毒（RSV）季节相关的出生时间以及出生顺序。
我们观察到春季和夏季出生的儿童患ALL的风险增加，与在生命的前三个月接触流感或RSV季节的儿童相比，那些在9至12个月大时首次接触流感或RSV季节的儿童患ALL的风险增加，并且这种关联在头胎儿童中更强[9至12个月大时接触流感的优势比（OR）为1.44，95%置信区间（CI）为1.13 - 1.82]。在非西班牙裔白人中，随着出生顺序增加风险降低，但在西班牙裔中未观察到这种情况（白人中第四胎或更高出生顺序的OR为0.76，95% CI为0.59 - 0.96）。
我们的结果支持幼儿期感染降低ALL风险的假设。
我们的研究结果表明，幼儿期接触感染是ALL的保护因素。
