Interactions between nutrition and immune function: using inflammation biomarkers to interpret micronutrient status

Abstract

The immune response promotes a complex series of reactions by the host in an effort to prevent ongoing tissue damage, isolate and destroy the infective organism and activate the repair processes that are necessary for restoring normal function. The homoeostatic process is known as inflammation and the early set of reactions that are induced are known as the acute phase response (APR). The APR has marked effects on the circulation, metabolism in the liver and the plasma concentration of many nutrients. The changes in nutrient concentrations follow a cyclic pattern; occurring before any clinical evidence of disease, being at their most pronounced during the disease and remaining in convalescence when all evidence of disease or trauma has disappeared. Therefore, where susceptibility to disease is high as in people who are HIV+ but still apparently healthy, obtaining an accurate measurement of nutritional status may not be possible. Accurate measurements of status are important for national statistics to plan for the proper utilisation of government resources and they are especially important to evaluate the effectiveness of nutritional interventions. Many acute phase proteins (APP) are synthesised during inflammation and they are used to monitor the progress of disease and recovery but, individually, none of their lifecycles compare well with those of the nutritional biomarkers. Nevertheless, recognising the presence of inflammation can help interpret data and, using two APP, this review paper will illustrate the methods we have developed to assist interpretation of plasma retinol, ferritin and zinc concentrations in apparently healthy, HIV+, Kenyan adults.

Species-Specific Associations Between Soil-Transmitted Helminths and Micronutrients in Vietnamese Schoolchildren

“…37 As with our ferritin results, we were not able to completely adjust for inflammation because AGP data were not available. 14 Our study has strengths and limitations. All three common STH infections were prevalent in this population, which meant the number of children with single infections by either Ascaris or Trichuris and with multiple infections were large enough to provide reasonable estimates for these groups separately.…”

Buffered or impaired: Maternal anemia, inflammation and breast milk macronutrients in northern Kenya

“…Non‐iron deficiency anemia (NIDA) includes anemia because of blood loss or red blood cell destruction, for example, resulting from infectious disease processes (particularly hookworm; Darnton‐Hill et al, ; Lynch, ; Thurnham & Northrop‐Clewes, ; Thurnham, ), as well as anemia resulting from micronutrient deficiencies other than iron deficiency. NIDA may also include cases with rarer chronic diseases such as autoimmune hemolytic anemia or bone marrow cancer; however, it is unlikely that these are important in explaining anemia in the current study in northern Kenya among seemingly healthy mothers.…”

“…In environments with high disease load and food insecurity, multiple types of anemia may coexist. Anemic individuals may be heterogeneous in terms of the primary causation of anemia, with some suffering anemia because of nutritional deficiencies or because of infection, whereas others have anemia from the combined effects of nutritional deficiencies, infection, and inflammation; similarly, infectious disease may be contributing to anemia both directly and through inflammatory pathways restricting the uptake, availability, and recycling of iron (Drakesmith & Prentice, ; Thurnham, ).…”

Research, policy, and programmatic considerations from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project

“…The impact of the APR on nutritional biomarkers is well known and documented in the literature (16–18). The APR is characterized by a complex and systemic inflammatory reaction to disruptions in the body’s homeostasis in response to infection, tissue damage, immunologic disorders, and other conditions.…”