[Serology of anti-Pseudomonas aeruginosa and mucoviscidosis: diagnostic aid in the differentiation between colonization and infection].

Serologic test for Pseudomonas aeruginosa have been found useful for differentiating colonization from infection, especially in chronic disease. A Western blot method was compared with the ELISA used routinely. The Western blot detected serum IgGs against P. aeruginosa outer membrane proteins, whereas the ELISA reacted with IgGs against soluble P. aeruginosa antigens. Among the 103 sera from 58 cystic fibrosis patients studied, all those with ELISA reactivity were positive by Western blot. The antibody response was detected earlier by Western blot than by ELISA, suggesting that the former technique may be useful for the early diagnosis of infection.