The role of secretory IgA (slgA) as a primary effector in protecting against both viral and bacterialpathogens has been examined by various investigators. Its function in the immune surveillance of tumors is less clear but has drawn increasing attention in recent years. It appears that IgA may be involved in the host response to a number of different epithelial tumors, including breast, uterine, prostate, oropharyngeal,and ovarian cancer.
Several investigators have described increased IgA levels in the serum of patients with lung cancer, but others have failed to confirm these observations.Elevations in IgA concentration have been noted more consistently in bronchial washings or bronchoalveolar lavage (BAL) obtained from a lobe that harbors a malignant neoplasm. Such elevations appear to be limited to fluid obtained from the tumorous lung,and the primary type of IgA is slgA. Although inflammatory lung conditions are also associated with elevations in local IgA concentration, the increases are significantly less than those seen with malignant neoplasms. levitra professional
These findings have led some investigators to speculate that measurement of slgA and/or IgG in bronchial fluid may have some practical clinical utility. Of note is the fact that all of the studies cited were retrospective and examined IgA levels in patients who were known to have lung cancer. To our knowledge, prospective analysis of the clinical utility of slgA measurements in a patient with an indeterminate pulmonary lesion has not been published. We report herein the results of a pilot study to determine the predictive value of BAL slgA measurements in patients with solitary pulmonary nodules.