Abstract
Secretory IgA (sIgA) and immunoglobulin (IgG, IgA, and IgM) in bronchoalveolar lavage fluid (BALF) of patients with bronchitis, pulmonary tuberculosis and lung cancer were measured.
The sIgA/alb ratio was highest in bronchitis followed by pulmonary tuberculosis. The level in bronchitis was significantly higher compared with controls. In lung cancer, the sIgA/alb ratio was not significantly different in each case. There was no difference between smokers and nonsmokers in levels of sIgA/alb ratio.
The IgA/alb ratio was high in pulmonary tuberculosis followed by bronchitis and lung cancer.
The IgG/alb ratio was high in pulmonary tuberculosis and bronchitis, the level in pulmonary tuberculosis showing a significant difference from controls, but IgM/alb did not show significant variations in all cases.
SIgA and IgA correlated significantly, but sIgA and IgG, sIgA and IgM did not.
Correlation between the sIgA level and microorganisms in BALF were examined. In cases with a sIgA/alb ratio of less than 0.1, increases of normal flora or low pathogenic microorganisms were observed. On the other hand, in cases with an sIgA/alb ratio of more than 0.1, numbers of microorganisms decreased.
