Lack of antibodies to Legionella pneumophila and Legionella micdadei in hemodialysis patients.

In 231 adult hemodialysis patients and 134 healthy adults, we measured antibodies to Legionella pneumophila (serogroups 1-6) and Legionella micdadei by indirect immunofluorescent antibody tests to assess the risk of Legionnaires' disease. One of the patients had a titer of 1:512 to Legionella pneumophila but he had no history of Legionnaires' disease. Two had a titer of 1:64 to Legionella pneumophila, and none had a titer of greater than or equal to 1:64 to Legionella micdadei. By contrast, none of the control group had a titer greater than or equal to 1:64 to Legionella pneumophila and two had a titer of 1:64 to Legionella micdadei. Thus, our population of maintenance hemodialysis patients did not display increased prevalence of antibodies of Legionella pneumophila and Legionella micdadei, but prospective studies of pneumonia in hemodialysis patients might further evaluate possible risk of Legionnaires' disease.