Can Childhood Stress Affect the Immune System?

Posted on November 27th, 2018 by Dr. Francis Collins

Katie Ehrlich
Credit: Alan Flurry, University of Georgia, Athens

Whether it’s growing up in gut-wrenching poverty, dealing with dysfunctional family dynamics, or coping with persistent bullying in school, extreme adversity can shatter a child’s sense of emotional well-being. But does it also place kids at higher of developing heart disease, diabetes, and other chronic health conditions as adults?

Katherine Ehrlich, a researcher at University of Georgia, Athens, wants to take a closer look at this question. She recently received a 2018 NIH Director’s New Innovator Award to study whether acute or chronic psychosocial stress during childhood might sensitize the body’s immune system to behave in ways that damage health, possibly over the course of a lifetime.

She’ll start her investigation by focusing on a familiar measure of biological response to an external event: the annual flu shot. Ehrlich will study 150 children who’ve received the flu vaccine to see if there’s any link between their levels of psychosocial stress and their blood levels of antibodies, which are immune molecules that the body generates to fend off the influenza virus.

What makes Ehrlich’s approach so innovative is it involves kids in real-time. For the past 30 years, most similar studies have asked adults to recall their childhood experiences and then associated those sometimes fuzzy memories with their current health status. The phenomenon of “recall bias” has often made it difficult to interpret such retrospective studies.

While most kids who get the flu vaccine are protected against the potentially fatal disease, there is a subset whose immune systems generate suboptimal levels of antibodies [1]. And even among kids who are protected, there exists tremendous variability in antibody levels among individuals [2]. Ehrlich hopes to be able to determine whether a child’s current sense of well-being, along with history of psychosocial stress, might help explain some of those differences. Possible stressors include poverty, racial discrimination, strained family relationships, harsh discipline, community violence, and limited social opportunities.

Ehrlich and her colleagues plan to follow their initial study with an analysis of the household dynamics of recently immunized kids. That follow-up work will include tapping into an ongoing, NIH-supported study called Strong African American Families Project (SHAPE), which involves low-income parents and their children in nine counties in rural Georgia. Ehrlich wants to look for specific psychosocial stressors associated with impaired immunity, as well as specific factors that may offset such stressors.

As Ehrlich notes, her research is just part of an emerging area of scientific inquiry that seeks to develop a more holistic view of the potential health impacts of the psychosocial stressors of childhood [3]. Among the various biological and behavioral questions being explored by such researchers are whether psychosocial stressors may produce a chronic, low-grade inflammatory state in some kids, resulting in health repercussions throughout their lives. Whatever the results may be, let’s hope that critical inroads can be made soon to find better ways to help all children thrive and grow into healthier adults.

References:

[1] Review: flu vaccines provide a moderate risk reduction in healthy children. Hulbert-Powell E, Pérez-Gaxiola G. Arch Dis Child Educ Pract Ed. 2012 Aug;97(4):164.

[2] Hemagglutination inhibition antibody titers as a correlate of protection for inactivated influenza vaccines in children. Black S, Nicolay U, Vesikari T, Knuf M, Del Giudice G, Della Cioppa G, Tsai T, Clemens R, Rappuoli R. Pediatr Infect Dis J. 2011 Dec;30(12):1081-1085.

[3] Early-Life Adversity and Physical and Emotional Health Across the Lifespan: A Neuroimmune Network Hypothesis. Nusslock R, Miller GE. Biol Psychiatry. 2016 Jul 1;80(1):23-32.

Links:

Katie Ehrlich (University of Georgia, Athens)

Center for Family Research (University of Georgia)

Strong African American Families Project (University of Georgia)

Ehrlich Project Information (NIH RePORTER)

NIH Support: Common Fund; National Institute on Minority Health and Health Disparities; National Center for Advancing Translational Research