Immunoserology of Pseudomonas aeruginosa infections in man. I. Four types of interaction between host and bacterium.

Continuous survey of clinical symptoms, bacteriological findings and anti-LPS antibodies in 39 acute and 9 chronic patients at a respiratory department revealed four interaction-types between Pseudomonas aeruginosa and host: I, clinical complications with a serological response; II, the same without serological answer; III, rise of specific antibodies without clinical symptoms; and IV, no clinical or serological reaction despite the presence of P. aeruginosa. Exogenous factors like massiveness or mode of infection (e.g. instrumental) determined mainly the type of interaction in the absence of immune-antibodies. P. aeruginosa colonization longer than a few days turned generally into manifest or subclinical infection. The lack of antibody production in severe infection was likely a consequence of an immune-paralysis, elicited by a massive infection. Antibody production was lower in subclinical than in manifest infection, yet IgG-type antibodies increased not only in the latter, but always in the former, too.