Occupational asthma is unique disease which offers the opportunity to monitor the development after removal from occupational allergens. The aim of our study was to ascertain whether the asthmatic problems continue or not after withdrawal from occupational allergen exposure.
We examined 37 patients with occupational asthma and 19 controls. The recent results of tests from asthmatics (obtained on average 6.5 years after elimination from occupational allergen exposure) were compared to results from the first visit in our department, and to the control group. Following parameters were checked: eosinophils, eosinophilic cationic protein (ECP), alpha-1-antitrypsin, total IgE in blood, skin prick tests, nonspecific bronchial hyperresponsiveness, spirometry and cell count in induced sputum.
In the group of asthmatics there were no significant changes (p<0.05) between results obtained in the first and recent visit for blood eosinophils, IgE, skin prick tests, bronchial challenge test, and spirometry. Nowadays elevated eosinophils in induced sputum were found in 25% from all examined samples of asthmatics. It was more often in asthmatics exposed to high molecular weight (HMW) allergens than in those exposed to low molecular weight (LMW) allergens (p<0.05). There were also more positive results of the present histamine challenges in HMW group than LMW group (p<0.05). Significant difference between group of asthmatics (more positive results) and control group was found for: prick tests, ECP, histamine challenge (p<0.05).
There was not significant improvement in observed parameters of the asthmatic group after withdrawal from occupational allergen exposure. Nowadays eosinophilic inflammation of airways and bronchial hyperreactivity has been more frequently present in patients exposed to HMW.
It seems that the exposure to HMW occupational allergens is worse for the future prognosis of development of asthma. It can be caused by a fact that it is less possible to avoid a contact with HMW agents in everyday life.
P. Klusackova, None.