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United States Department of Agriculture

Agricultural Research Service

Research Project: NUTRITION, AGING, IMMUNE AND INFLAMMATORY RESPONSES IN HEALTH AND DISEASES

Location: Human Nutrition Research Center on Aging

Title: Obesity impairs cell-mediated immunity during the second trimester of pregnancy

Authors
item Sen, Sarbattama -
item Iyer, Chitra -
item Klebenov, David -
item Histed, Alexander -
item Aviles, Jessica -
item Meydani, Simin -

Submitted to: American Journal of Obstetrics and Gynecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 8, 2012
Publication Date: February 15, 2013
Citation: Sen, S., Iyer, C., Klebenov, D., Histed, A., Aviles, J.A., Meydani, S.S. 2013. Obesity impairs cell-mediated immunity during the second trimester of pregnancy. American Journal of Obstetrics and Gynecology. 208(139):e1-8.

Interpretive Summary: Over half the women of reproductive age in the US today are overweight or obese. Women who are obese before pregnancy have increased complications during formation of the fetus, before and after childbirth, and in the first month after the birth of the child. Obesity is associated with an impaired immune system. Both mother and fetus are susceptible to the short- and long-term harmful effects of infectious illness. However, the mechanism and extent that the immune system is weakened in obese pregnancy still needed to be defined. The objective of the study was to determine the impact of obesity on maternal blood immune cells, important proteins (called cytokines) that can trigger inflammation and respond to infection and white cell production. Our study recruited 30 women in their second trimester of pregnancy, 15 obese and 15 lean. Our results showed that unlike the lean pregnant women, obese pregnant women had a weakened ability for the immune system to activate the specialized cells that fight and destroy invading harmful organisms or abnormal cells the body may produce. This is the first study to show specific components of the immune system that are weakened in obese pregnancy. As obese pregnancy becomes more common, it is imperative to better understand its consequences. We show, for the first time, that women who are obese before pregnancy have an impaired immune response and, thus, an increased risk for specific infections, which could harm both mother and fetus. Based on the difference found between immune cell function in obese and lean pregnant women, more vigilance and aggressive treatment of infectious illnesses occurring in obese pregnant women would be recommended due to their impaired immune response.

Technical Abstract: Obesity is associated with impaired immunity. In obese pregnancy, both mother and fetus are susceptible to the short- and long-term deleterious effects of infectious illness. The objective of the study was to determine the impact of obesity on maternal blood immune cell subsets, intracellular and serum cytokine production and lymphocyte proliferation. This was a prospective case control study, with 15 obese (BMI is greater than30) and 15 lean (BMI 18-25) subjects recruited during the second trimester of pregnancy. Immune cell subsets, intracellular and serum cytokine production and lymphocyte proliferation were measured in maternal blood. Our results show that obese pregnancy is associated with impaired cell mediated immunity. We found that obese pregnant women had significantly fewer CD8+ and NK cells and more B cells, impaired cytokine production when stimulated ex vivo and impaired ability of lymphocytes to proliferate compared to their lean counterparts. As obese pregnancy becomes more common, it is imperative to better understand its repercussions. We show, for the first time, that women who are obese before pregnancy have an impaired immune response and, thus, an increased risk for specific infections, which could harm both mother and fetus.

Last Modified: 7/24/2014
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