Lactoferrin and secretory IgA in the bronchoalveolar lavage fluid from patients with a stable asthma.

We have measured lactoferrin and secretory IgA (sIgA) in the unconcentrated bronchoalveolar lavage fluid (BALF) from nonsmoking healthy volunteers (n = 10) and nonsmoking patients with stable asthma (n = 14). The median concentrations and the ranges of lactoferrin were controls, 0.13 mg/L (0.01-0.43 mg/L); asthma, 0.41 mg/L (0.07-7.51 mg/L). For sIgA the results were controls, 0.48 mg/L (0.12-1.47 mg/L); asthma, 1.29 mg/L (0.65-14.6 mg/L). The concentrations in the epithelial lining fluid (ELF) were calculated on the basis of urea in BALF and serum. SIgA and lactoferrin levels in the BALF and ELF from the patients with asthma were higher than in controls (Mann-Whitney U-test, p less than 0.03). Our results indicate that in patients with stable asthma the airway epithelial cells are activated, resulting in an enhanced secretion of lactoferrin and enhanced secretory transport of sIgA into the airway lumen.