Study of employees with anhydride-induced respiratory disease after removal from exposure

The purpose of this study was to determine clinical and immunologic status of hexahydrophthalic anhydride (HHPA) employees who have had immunologic respiratory disease and who have been removed from exposure for at least 1 year. In a retrospective study, 16 consecutive employees with HHPA-induced immunologic respiratory disease who had been removed from exposure for more than 1 year were evaluated. Eleven had asthma, allergic rhinitis, or both; five had hemorrhagic rhinitis. Respiratory symptoms were obtained by physician-administered questionnaire. Physical examination, spirometry, and chest film were obtained. Antibody against HHPA conjugated to human serum albumin (HHP-HSA) was determined by enzyme-linked immunosorbant assay. Symptoms, signs, and pulmonary functions were normalized in all employees. There was a decline in antibody titers for both IgE and IgG against HHP-HSA. There were no chest film findings attributable to HHPA. In this group, there appeared to be no evidence of permanent anatomic sequelae after removal from exposure for at least 1 year. Specific antibody was still present, but titers were lower at follow-up than at presentation for a substantial proportion of the sample.