Constant defect in neutrophil locomotion but with age decreasing susceptibility to infection in Shwachman syndrome.
Chemotaxis, phagocytosis and bactericidal activity of neutrophils obtained from eight patients with Shwachman syndrome were studied repeatedly over a 9 year period. In a membrane filter the patient neutrophils migrated both toward casein and toward zymosan activated serum significantly less than did the control cells. Chemokinetic migration in casein was likewise significantly impaired. As determined by agarose assay, random locomotion of the patient neutrophils was significantly depressed. The differences in phagocytosis and bactericidal activity between the patients and the control subjects were not significant. However, phagocytosis by neutrophils obtained from healthy subjects was significantly impaired in sera from four patients, compared with that in control sera. The follow-up study showed the neutrophil migration defect to be constant in repeated tests, whereas infectious episodes diminished in number after the patients reached the age of 3-7 years.