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Wheezing and asthma may be enhanced by broad spectrum antibiotics used in early childhood. Concept and results of a pharmacoepidemiology study

100%

Jedrychowski W., Perera F., Maugeri U., Mroz E., Flak E., Perzanowski M., Majewska R.

Journal of Physiology and Pharmacology

2011

tom 62

nr 2

One of the mechanisms supposed to explain the increasing prevalence of asthma, among children in particular, is the use of antibiotics because they may modify natural microbial exposure and development of the immune system in early childhood. The aim of this study is to investigate the association between the use of various classes of antibiotics (penicillin, cephalosporin and macrolide derivatives) in early childhood and the medical diagnosis of asthma or wheezing reported by mothers over the follow-up after adjustment for potential confounders and respiratory infections. In a population-based sample of 5-year-olds, a part of the ongoing birth cohort study, the standardized interviews on health outcomes, potential confounders (child’s gender, maternal atopy, parity, prenatal and postnatal environmental tobacco smoke) and the use of antibiotics were gathered from mothers of 310 children. While the overall use of antibiotics during the early childhood was insignificantly associated with asthma (adjusted OR = 1.65, 95%CI: 0.93 – 2.93), the risk estimates were significant both for macrolide antibiotics (adjusted OR=2.14, 95%CI: 1.16–3.95) and cephalosporins (OR=1.98, 95%CI: 1.14–3.37). The significant excess in IRR (incident risk ratio) of wheezing episodes was related only to the use of macrolide antibiotics (adjusted IRR=1.91, 95%CI: 1.12–3.27). The use of other classes of antibiotics was found not to be associated with the medical diagnosis of asthma or wheezing episodes recorded in the study period. Conclusion: as early childhood use of broad spectrum antibiotics is associated with an increased risk of developing asthma in 5-year-olds, it may be hypothesized that the antibiotic- related suppression of allergic inflammatory responses in the course of treatment may later lead to greater than before atopic immune response in Th2 children or an impairment of Th1 immune responses in early childhood.

Molecules released by helminth parasites involved in host colonization

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Dzik J. M.

Acta Biochimica Polonica

2006

tom 53

nr 1

Parasites are designed by evolution to invade the host and survive in its organism until they are ready to reproduce. Parasites release a variety of molecules that help them to penetrate the defensive barriers and avoid the immune attack of the host. In this respect, particularly interesting are enzymes and their inhibitors secreted by the parasites. Serine-, aspartic-, cysteine-, and metalloproteinases are involved in tissue invasion and extracellular protein digestion. Helminths secrete inhibitors of these enzymes (serpins, aspins, and cystatins) to inhibit proteinases, both of the host and their own. Proteinases and their inhibitors, as well as helminth homologues of cytokines and molecules containing phosphorylcholine, influence the immune response of the host biasing it towards the anti-inflammatory Th2 type. Nucleotide-metabolizing enzymes and cholinesterase are secreted by worms to reduce inflammation and expel the parasites from the gastrointestinal tract. An intracellular metazoan parasite, Trichinella spiralis, secretes, among others, protein kinases and phosphatases, endonucleases, and DNA-binding proteins, which are all thought to interfere with the host cellular signals for muscle cell differentiation. Secretion of antioxidant enzymes is believed to protect the parasite from reactive oxygen species which arise from the infection-stimulated host phagocytes. Aside from superoxide dismutase, catalase (rarely found in helminths), and glutathione peroxidase (selenium-independent, thus having a poor activity with H2O2), peroxiredoxins are probably the major H2O2-detoxifying enzymes in helminths. Secretion of antioxidant enzymes is stage-specific and there are examples of regulation of their expression by the concentration of reactive oxygen species surrounding the parasite. The majority of parasite-secreted molecules are commonly found in free-living organisms, thus parasites have only adapted them to use in their way of life.

Ograniczanie wyników

1 Acta Biochimica Polonica

1 Journal of Physiology and Pharmacology

1 Dzik J. M.

1 Flak E.

1 Jedrychowski W.

1 Majewska R.

1 Maugeri U.

1 Mroz E.

1 Perera F.

1 Perzanowski M.

1 2011

1 2006

Wyniki wyszukiwania

Wheezing and asthma may be enhanced by broad spectrum antibiotics used in early childhood. Concept and results of a pharmacoepidemiology study

Molecules released by helminth parasites involved in host colonization