Department of Anthropology, University of Washington, Seattle, Washington, USA.
Center for Studies in Demography and Ecology, University of Washington, Seattle, Washington, USA.
Am J Phys Anthropol. 2021 Feb;174(2):213-223. doi: 10.1002/ajpa.24191. Epub 2020 Dec 9.
Microchimerism is the presence of a small quantity of cells or DNA from a genetically distinct individual. This phenomenon occurs with bidirectional maternal-fetal exchange during pregnancy. Microchimerism can persist for decades after delivery and have long-term health implications. However, little is known about why microchimerism is detectable at varying levels in different individuals. We examine the variability and the following potential determinants of maternal-origin microchimerism (MMc) in young women in the Philippines: gestational duration (in utero exposure to MMc), history of being breastfed (postpartum exposure to MMc), maternal telomere length (maternal cells' ability to replicate and persist), and participant's pregnancies in young adulthood (effect of adding fetal-origin microchimerism to preexisting MMc).
Data are from the Cebu Longitudinal Health and Nutrition Survey, a population-based study of infant feeding practices and long-term health outcomes. We quantified MMc using quantitative PCR (qPCR) in 89 female participants, ages 20-22, and analyzed these data using negative binomial regression.
In a multivariate model including all predictors, being breastfed substantially predicted decreased MMc (detection rate ratio = 0.15, p = 0.007), and there was a trend of decreasing MMc in participants who had experienced more pregnancies (detection rate ratio = 0.55, p = 0.057).
These results might be explained by breastfeeding having lasting impact on immune regulatory networks, thus reducing MMc persistence. MMc may also decrease in response to the introduction of fetal-origin microchimerism with pregnancies experienced in adulthood.
微嵌合是指存在来自遗传上不同个体的少量细胞或 DNA。这种现象发生在妊娠期间的双向母婴交换中。微嵌合可以在分娩后持续数十年，并对长期健康产生影响。然而，人们对为什么微嵌合在不同个体中以不同水平检测到知之甚少。我们研究了菲律宾年轻女性中母体来源微嵌合（MMc）的变异性和以下潜在决定因素：妊娠期（胎儿期暴露于 MMc）、母乳喂养史（产后暴露于 MMc）、母体端粒长度（母体细胞复制和持续存在的能力）以及参与者在年轻成年时的妊娠（将胎儿来源的微嵌合添加到预先存在的 MMc 中的影响）。
数据来自宿务纵向健康和营养调查，这是一项关于婴儿喂养实践和长期健康结果的基于人群的研究。我们使用定量 PCR（qPCR）在 89 名年龄在 20-22 岁的女性参与者中量化了 MMc，并使用负二项式回归分析了这些数据。
在包括所有预测因素的多变量模型中，母乳喂养大量预测 MMc 减少（检测率比 = 0.15，p = 0.007），并且经历更多妊娠的参与者的 MMc 呈减少趋势（检测率比 = 0.55，p = 0.057）。
这些结果可能可以通过母乳喂养对免疫调节网络产生持久影响来解释，从而减少 MMc 的持续存在。随着成年时经历的妊娠，MMc 也可能会减少以响应引入胎儿来源的微嵌合。
