Asthma, wheezy bronchitis, and atopy across two generations

Although the prevalence of asthma has risen significantly during the last 3 0 yr, it is not clear whether this has occurred primarily in persons with a strong genetic predisposition to asthma and atopy or in other sections of the population. We have investigated outcomes in children of nuclear famili es selected through probands previously characterized by studies in 1964 an d 1989 as having histories of persistent childhood onset atopic asthma, tra nsient childhood wheezy bronchitis, and no respiratory symptoms or atopy. C hildren of wheezy bronchitic probands had a significantly better symptomati c outcome in adolescence, irrespective of the atopic status of the parent p roband, than do children of either asthmatic or asymptomatic probands, sugg esting that this may be a syndrome that shows familial aggregation and is d istinct from asthma. Total serum IgE levels were significantly lower in chi ldren of nonatopic asymptomatic probands, including those with wheezing sym ptoms. In contrast children of nonatopic asymptomatic probands had an unexp ectedly high prevalence of wheezing (33%), positive skin prick tests (56%), and positive specific serum IgE to common allergens (48%) that was similar to that found in children of atopic asthmatic probands. Our findings suppo rt the concept that wheezy bronchitis is a separate syndrome from atopic as thma. High total serum IgE levels within our population appear to be an imp ortant marker of genetic predisposition to atopy. Our data also suggest tha t much of the increase in asthma prevalence is associated with specific IgE sensitization and is occurring in persons previously considered to be at l ow risk of developing asthma or atopy.