The value of precipitating antibodies in screening for hypersensitivity pneumonitis

To evaluate the usefulness of precipitin tests as a screening method to detect hypersensitivity pneumonitis, we compared persons with precipitins to organic antigens with precipitin-negative subjects from the same population of 1,072 office workers participating in a health survey examination. Thirty-three of the 53 persons with preciptins to Micropolyspora faeni, Thermoactinomyces vulgaris, T. candidus, pigeon serum, aspergillus, alternaria, pullularia, penicillium, cephalosporium, trichoderma, and phoma were matched according to age, sex, height, and smoking habits with precipitin-negative subjects. The subjects completed a self-administered standard questionnaire, they were interviewed and examined, chest radiograms were taken, and pulmonary functions were evaluated at rest and during mild and moderate exercise. No significant differences were found between the 2 populations in any of the pulmonary function measurements. In addition, clinical and radiologic evidence failed to distinguish between the 2 groups. No cases of hypersensitivity pneumonitis were found. In this population, precipitins had no apparent relationship to long disease. The frequency of precipitins was considerably higher than the frequency of hypersensitivity pneumonitis. We concluded that the detection of hypersensitivity pneumonitis in population surveys attempting to establish prevalence of the disease cannot be accomplished by the simple analysis of serum precipitating antibodies but requires, in addition, a more complex analysis of historical, radiologic, and immunologic data.