Age Dependence in Food Allergy, First Exposure

Exposure of children to tobacco smoke has been found to increase IgE concentration and the tendency to develop eosinophilia, it also increased the percentage of children allergic to indoor allergens (Kabesch and Mutius, 2000). 

A few years ago the first findings appeared which undermined this concept. It was noticed that the children who did not develop diseases in childhood, develop allergies more often. Moreover it was reported that children who stayed in rural areas, where exposure to allergens and bacterial endotoxins was greater than in urban areas, less frequently developed diseases (Braun-Fahrlander, 2000 Von Mutius et al., 2000 Remes et al., 2003 Gehring et al., 2004). 

TLRs are found everywhere in the human body—in the epithelium, APC cells, eosinophils, mastocytes, neutrophils, B lymphocytes, vascular endothelial cells, keratinocytes, adipocytes, cardiomyocytes, and fibroblasts. Most of them are present on the cell surface, some are present in the cytoplasm, as they bind with antigens of endocellular microorganisms, which have undergone degradation in proteasome and lysosomes. 

Modifying primary and secondary immunological response by Bifidobacterium and Lactobacillus probiotics is linked with their structures being recognized by TLR 9 present on monocytes and lymphocytes, as well as with TLR expression on dendritic cells. As a result, release of IL 12 and IFNy is increased. Also preferential recruitment of Thl lymphocytes has been observed. Saito made a hypothesis that individually selected TLR ligand doses might be administered as a medicine to infants at risk of allergy (Saito et al., 2003). 

In order to reduce the risk of allergy, use of medicines has been tested. It seems an interesting idea to use tetracyclines deprived of antibiotic properties (mino and doxy-cyklines), administered orally to mice to reduce Ig E concentration. An inversely proportional relationship to the dose has been reported (Durkin et al., 2007). 

---