CLINICAL SYMPTOMS AND RESULTS OF SKIN-TEST, RAST AND BRONCHIAL PROVOCATION TEST IN 33 PAPAIN WORKERS - EVIDENCE FOR STRONG IMMUNOGENIC POTENCY AND CLINICALLY RELEVANT PROTEOLYTIC EFFECTS OF AIRBORNE PAPAIN

Of 3 workers who were exposed to airborne papain at their place of work 17 regularly developed asthmatic symptoms such as shortness of breath, wheezing, coughing, sneezing, rhinorrhea and conjunctival irritation upon contact with this proteolytic enzyme. Investigations by RAST [radioallergosorbent test], skin test and bronchial provocation test proved IgE-mediated hypersensitivity to papain in 14 symptomatic workers. Then of these were in a screening investigation involving 29 of the 33 workers; i.e., the incidence of IgE-mediated sensitization was 34.5% of this group. Bronchial provocation of as little as 0.001 -0.5 mg of papain elicited immediate or dual asthmatic reactions in all 8 tested workers with RAST values > 3 u/ml. Inhalation of 0.5 mg of papain did not cause any remarkable change in non-exposed asthmatics. Occupation-related blood-stained nasal secretions and/or cutaneous flare reactions in all 4 heavily-exposed papain workers, of whom 3 had negative skin test and RAST results, suggest a direct reffect of the proteolytically active enzyme on human tissue. There was a significant elevation (P < 0.001) of serum trypsin inhibitory capacity in papain workers which seems to depend on the degree of exposure. No significant differences between symptomatic and asymptomatic workers in .alpha.1-antitrypsin phenotype subtypes were found.