[Measurement of formaldehyde-specific IgE antibodies in adult asthmatics]

Formaldehyde (FA) is known to be a potent contact sensitizer eliciting dermatitis or bronchial asthma in occupational settings. However, several pieces of recent evidence indicate that FA is a participant of indoor air pollution even at home and that it may be one of the causative agents for the sick-house syndrome. In the present study, we examined whether production of FA-specific IgE antibody (FA-IgE) occurred in adult chronic asthmatics or not. We randomly selected 80 adult asthmatics, and obtained blood sampling under the condition where the symptoms were well controlled. We measured FA-IgE, eosinophil count and serum concentration of eosinophil cationic protein (sECP), and also measured lung functions (FEV1%, %VC, V25/HT). We found that FA-IgE was positive in two patients (33-year-old female and 56-year-old male), while negative (less than 0.35 UA/ml) in the others. State of asthma was severe in the female patient, while mild intermittent in the male patient. In the female patient, the total IgE titer and the FA-IgE titer were 181 IU/ml and 0.81 UA/ml, respectively, and there was no occupational environments concerning FA. In the male patient, both the total IgE and the FA-IgE titer were quite high (8400 IU/ml and 2.99 UA/ml, respectively). In this case, there was an occupational environment where the adhesive smell was strong. sECP was 44.2 micrograms/l in the female patient, while 4.7 micrograms/l in the male patient. In the present study, IgE-mediated allergy for FA was rare in adult chronic asthmatics, and the FA-IgE titer did not seem parallel to severity or pathophysiological condition in bronchial asthma. But, further development of precise methodology for clinically clarifying FA-mediated mechanisms in allergic disorders, might be still important.