The implications of nomenclature.
BACKGROUND
To be able to draw the right conclusions from clinical research, it is essential that words have the same meaning to all researcher and clinicians.


OBJECTIVE
To present the new nomenclature for allergy and discuss its influence on conclusions drawn from clinical studies with one example illustrating that conclusions change with the use of definitions and nomenclature.


METHODS
To review one recent study at odds with the new allergy nomenclature. Atopy is defined as a personal or familial tendency to produce immunoglobulin (Ig)E antibodies in response to low doses of allergens, usually proteins, and to develop typical symptoms such as asthma, rhinoconjunctivitis, or eczema/dermatitis. Allergy is defined as a hypersensitivity reaction initiated by immunologic mechanisms and divided into IgE-mediated and non-IgE-mediated allergy. What has been called atopic diseases, eg, infantile eczema, can be caused by both IgE-mediated allergy (atopy) and non-Ig-mediated mechanisms. In the study, two groups of mothers/infants were given either Lactobacillus GG or placebo with the incidence of infantile eczema as primary outcome parameter.


RESULTS
The study analyzed concludes that probiotic bacteria supplied to mother and child prevents infantile eczema development caused by both IgE-mediated (atopy) and non-IgE-mediated allergic mechanisms. The study also shows that IgE sensitization was similar in the two groups. Thus, "atopic disease" was prevented (subjective evaluation), whereas atopy, ie, IgE induction was not prevented.


CONCLUSIONS
Nomenclature is of utmost importance to interpret results in allergy research. If preventive measures, such as oral treatment with Lactobacilli, have an effect, this should be tested against a single mechanism of disease rather than against a disease caused by several mechanisms. However, in the study Lactobacilli are said to prevent atopic disease, and also that Lactobacilli do not hinder development of IgE sensitization, one of the mechanisms causing this disease.
Dreborg
Sten
S
sten.dreborg@telia.com
D000818:Animals; D002417:Cattle; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000145:classification / Q000276:immunology / Q000517:prevention & control; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000145:classification*; D006969:Hypersensitivity, Immediate / Q000145:classification*; D007070:Immunoglobulin A / Q000032:analysis; D007223:Infant; D008892:Milk / Q000276:immunology; D019936:Probiotics; D009626:Terminology as Topic
D007070:Immunoglobulin A