A prospective pilot study evaluating the effectiveness of secretory IgA measurements in bronchoalveolar lavage to detect non-small cell lung cancer

Previous studies have described significant elevations in the concentrations of secretory immunoglobulin A (sIgA) in bronchial washings obtained from cancerous lungs. To date, there have been no prospective investigations examining the predictive value of sIgA measurements in clinically relevant settings. Our goal was to determine if measurement of sIgA in bronchoalveolar lavage (BAL) at the time of bronchoscopic evaluation of potentially malignant lung nodules might prospectively predict the presence of cancer. We observed no significant increase in the sIgA obtained from eight BALs obtained from cancerous lungs as compared with BALs taken from these same patients' contralateral cancer-free lungs. We also saw no significant difference in BAL (sIgA) obtained from patients eventually found to have cancer (N = 8) as compared with those found to have noncancer diagnoses (N = 6). In light of these findings, we think it unlikely that measurement of sIgA will be clinically useful in the diagnosis of pulmonary malignant neoplasms.