Serum antibodies to Aspergillus fumigatus catalase in patients with cystic fibrosis.

Seven to ten percent of patients with cystic fibrosis had serum antibodies to the catalase antigen of Aspergillus fumigatus in three cross-sectional surveys between 1977 and 1984. A total of 208 patients participated at least once, and the cumulated frequency of catalase antibodies in 94 patients included in all three surveys was 16%. The titre range was 1 to 16. The prevalence rate of Aspergillus fumigatus in sputum was 50% for a 2.5-year observation period. Catalase antibodies were strongly associated with the occurrence of Aspergillus fumigatus in sputum (p = 0.003), and the microorganism was more numerous in colonized patients with catalase antibodies than in those without such antibodies (p = 0.004). Patients with Aspergillus fumigatus in sputum and a positive catalase antibody test tended to have an adverse development as regards lung function compared to both carriers without antibodies and non-carriers. The observed differences could not, however, be related to different rates of chronic Pseudomonas aeruginosa infection.