An ELISA to detect antipseudomonal IgA antibodies in sera of patients with cystic fibrosis.

ABSTRACT

An enzyme linked immunosorbent assay (ELISA) to measure free serum IgA antibodies to Pseudomonas aeruginosa in patients with cystic fibrosis is described. Results were reproducible and there was no interference from crossreacting antibodies directed against other Gram negative bacteria. Titres were high in patients with Pseudomonas aeruginosa infection and differed according to the stage of the infection. These preliminary results suggest that this assay may be of value in assessing the state of Pseudomonas aeruginosa infection in patients with cystic fibrosis.