In vitro migration of alveolar macrophages was studied in 24 fire victims and 19 controls; all subjects were cigarette smokers. Unstimulated (P = 0.01) and stimulated migration towards
casein-(P = 0.01) and
zymosan-activated serum (P = 0.002) of macrophages from
smoke inhalation patients (SI) (n = 19) was increased when compared to control subjects (CS). Migration of alveolar macrophages from patients with
burns without
smoke inhalation (burns only, BO) was not increased. Patients with
smoke inhalation and no
burns (
smoke only, SO) (n = 9) had increased migration when compared to controls but this was not statistically significant. Patients with
smoke inhalation and
burns (SB) (n = 10) had increased unstimulated migration (P = 0.01) and increased migration towards
casein (P less than 0.005), ZAS (P less than 0.002) and
F-met-leu-phe (P less than 0.05) when compared to controls (CS). Lavage fluid from the fire victims displayed chemotactic activity towards normal human neutrophils and its analysis for the components of the
complement cascade proved positive (Clq, Clr,
Factor B and C3). These data suggest that activation of alveolar macrophages may contribute to the development of pathophysiological changes in patients with
smoke inhalation (SI) and particularly those with
smoke inhalation and
burns (SB).