Clinical and immunological responses to enzymes of Bacillus subtilis in factory workers and consumers


Professor J. Pepys, Department of Clinical Immunology, Cardiothoracic Institute, Brompton Hospital, London, S.W.3.


Skin (prick) and serological tests were made with enzyme preparations of Bacillus subtilis in exposed factory workers and potential ‘consumers’. Prick tests with these materials at 10 mg/ml gave positive immediate reactions in twenty-six out of sixty-five factory workers. Eighteen of the factory workers were classified as atopic because of allergy to common allergens and fifteen gave positive reactions to the enzymes compared with eleven out of forty-seven non-atopic workers. A group of eleven of the factory workers had consistent ventilatory impairment on repeated examination; all were prick test positive and seven were atopic, and four non-atopic.

Of 2500 patients attending for investigation of respiratory allergy, 40% were highly atopic, 40% moderately atopic and 20% non-atopic. 80% were consumers of biological detergents. Only two gave weak, not clinically relevant, prick test reactions to the enzyme preparations.

In radioallergosorbent (RAST) tests for specific IgE antibody against the enzyme preparations, counts in the present investigation of 600/30 sec or more corresponded best with prick test positivity, such values being found in twelve of the fifteen prick test positive atopics and in eight of the eleven workers with ventilatory impairment.

Comparison of the RAST counts on sera from cord blood and from the patients who included non, light and heavy consumers showed increasingly higher specific IgE counts in these groups, although these counts were almost all below the level of 600/30 sec, which corresponded with skin test reactions and clinical relevance.

Radioimmunodiffusion (RID) and radioimmunoelectrophoretic (RIEP) tests with enzyme preparations gave positive reactions only in the factory workers, of whom forty-three had IgG and twenty-one IgA antibody, none having only IgE antibody.