The early life origins of asthma and related allergic disorders
- Correspondence to:
Prof. J O Warner
Professor of Child Health, Allergy & Inflammation Sciences, Division of Infection, Inflammation & Repair, School of Medicine, University of Southampton, UK;
A focus on the way the disease evolves in early life
Pharmacological treatment of established asthma is highly effective in controlling symptoms and improving quality of life. However, no treatment has been hitherto shown to modify the natural course of the disease and no cure has been identified. Indeed the best predictors of continuing asthma into adulthood are: early age of onset; sensitisation to house dust mites; reduced lung function; and the presence of bronchial hyperresponsiveness in childhood, irrespective of therapy.1 This suggests that we have made little progress in understanding the basic causes of the disease than was the case in the 12th century when Moses Ben Maimon, Jewish physician and philosopher, wrote in his handbook for his patient, the Sultan Saladin’s son, “I have no magic cure to report. Asthma has many aetiological aspects and should be treated according to the various causes that bring it about”.2 Under such circumstances, attention should continue to focus on understanding the way in which the disease evolves in early life, in order to identify targets for primary preventive therapy.
FETAL RESPONSES TO ALLERGENS
It should not be surprising to any paediatrician that the fetus is capable of mounting sophisticated immune responses. All will be familiar with the antenatal immune response in relation to the detection of IgM antibodies from as early as 20–26 weeks gestation in fetuses of mothers infected with rubella in early pregnancy.3 Tetanus toxoid specific IgM can be detected in the cord blood of infants whose mothers were immunised during pregnancy.4 Direct immunisation of fetal baboons with recombinant hepatitis B surface antigen results in specific IgG detectable in the fetal but not maternal circulation, and subsequent postnatal immunisation results in an enhanced production of antibodies.5 These studies show that the entrenched paradigm that early antigen exposure induces …