Elsevier

Advances in Nutrition

Volume 5, Issue 6, November 2014, Pages 702-711
Advances in Nutrition

Undernutrition, the Acute Phase Response to Infection, and Its Effects on Micronutrient Status Indicators

https://doi.org/10.3945/an.114.006361Get rights and content
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ABSTRACT

Infection and undernutrition are prevalent in developing countries and demonstrate a synergistic relation. Undernutrition increases infection-related morbidity and mortality. The acute phase response (APR) is an innate, systemic inflammatory reaction to a wide array of disruptions in a host's homeostasis, including infection. Released from immune cells in response to deleterious stimuli, proinflammatory cytokines act on distant tissues to induce behavioral (e.g., anorexia, weakness, and fatigue) and systemic effects of the APR. Cytokines act to increase energy and protein requirements to manifest fever and support hepatic acute phase protein (APP) production. Blood concentrations of glucose and lipid are augmented to provide energy to immune cells in response to cytokines. Additionally, infection decreases intestinal absorption of nutrients and can cause direct loss of micronutrients. Traditional indicators of iron, zinc, and vitamin A status are altered during the APR, leading to inaccurate estimations of deficiency in populations with a high or unknown prevalence of infection. Blood concentrations of APPs can be measured in nutrition interventions to assess the time stage and severity of infection and correct for the APR; however, standardized cutoffs for nutrition applications are needed. Protein-energy malnutrition leads to increased gut permeability to pathogens, abnormal immune cell populations, and impaired APP response. Micronutrient deficiencies cause specific immune impairments that affect both innate and adaptive responses. This review describes the antagonistic interaction between the APR and nutritional status and emphasizes the need for integrated interventions to address undernutrition and to reduce disease burden in developing countries.

Abbreviations

ACT
antichymotrypsin
ACTH
adrenocorticotropic hormone
AGP
α1-acid glycoprotein
APP
acute phase protein
APR
acute phase response
CRP
C-reactive protein
MRDR
modified relative dose response
PEM
protein-energy malnutrition
RBP
retinol-binding protein

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Supported by Global Health funds at the University of Wisconsin-Madison during manuscript preparation and HarvestPlus contract 8256. HarvestPlus (www.harvestplus.org) is a global alliance of agriculture and nutrition research institutions working to increase the micronutrient density of staple food crops through biofortification. The views expressed do not necessarily reflect those of HarvestPlus.

Author disclosures: K. A. Bresnahan and S. A. Tanumihardjo, no conflicts of interest.