Non-invasive assessment of inflammation

Iron status and inflammation are mutually interrelated in many ways: Iron is essential for bacteria and parasites which, therefore, need to access the host’s iron stores. Moreover, they are in fierce competition for this resource among each other. The host, in turn, tries to keep iron scarce as part of his defense-strategy against diseases. For this reason, iron supplementation may be detrimental for health, as has been shown for malaria (R23) and other infective diseases.

Inflammation induces hepcidin synthesis which reduces iron absorption and sequesters body iron in the reticuloendothelial system (RES). These mechanisms may lead to “anaemia of inflammation”, as we showed for Guatemalan children on dialysis (IS2). Environmental influences, like work hygiene and smoke from indoor fire-places, can aggravate inflammation. Moreover, obesity goes along with low level inflammation (R25, R26). Due to this situation methods to assess the extent of low-level inflammation have become important. Such methods should preferentially be non-invasive for easy handling, to increase their acceptance by children, and to avoid the risk of spreading communicable diseases, such as hepatitis and HIV. A variety of such methods is available but so far failed the test in the field by comparing the results to those of established invasive methods.

To assess the inflammatory status without blood sampling, inflammatory markers can be detected in stool or saliva. Alternatively, inflammation can be assessed by transcutaneous reflex photometry to monitor reactions of the microcirculation. Dr. Soto-Mendez is in charge of this cluster that presently consists of five sub-projects.