The Journal of Thoracic and Cardiovascular Surgery, Vol 82, 63-69, Copyright © 1981 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Function of the secretory immune system in bronchogenic carcinoma. Immunoglobulin A levels in respiratory secretions
JD Iglehart, MJ Warzynski, RC Montelaro, DP Bolognesi, DC Sabiston Jr and WG Wolfe
This study was designed to investigate the association between bronchogenic
carcinoma of the lung and elevated immunoglobulin A (IgA) levels in
respiratory secretions. Sixty-nine patients underwent bronchoscopic
examination for evaluation of benign and malignant pulmonary diseases. The
concentration of IgA in bronchoscopic washings was determined by a
radioimmunoassay (RIA) procedure. The average IgA concentration in 20
washings from patients with benign disease was 171 micrograms/ml and agreed
with reported IgA values in normal human volunteers undergoing
bronchoscopic examination. In contrast, the average IgA concentration from
patients with non--oat cell bronchogenic carcinoma was greater than 1,000
micrograms/ml, and 80% of these patients had values exceeding 300
micrograms/ml. Furthermore, in 16 of these patients, selectively collected
washings had been obtained from the tumor-bearing lung and contralateral
normal lung. In this group, elevated levels localized to the tumor-bearing
side. In contrast, eight patients with extrathoracic cancer metastatic to
the chest had an average IgA value of 160 micrograms/ml, and seven of eight
(87%) had concentrations below 300 micrograms/ml. Aside from the
association of cigarette smoking and pulmonary cancer, we found no clear
relationship between smoking history and the concentration of IgA measured
in secretions. Finally, biochemical analysis established that the changes
in immunoglobulin levels were specific to the secretory immune system. In
conclusion, measurement of secretory immune system components may be useful
in the early diagnosis of malignant bronchogenic disease. Biological
mechanisms and suggested clinical application are discussed.