Immunoglobulin content in the bronchial washings of patients with benign and malignant pulmonary disease.

The bronchial washings of 58 patients with benign and neoplastic conditions involving the lungs were evaluated for immunoglobulin content. Levels in the washings from the diseased lung were compared with those from the normal contralateral lung. In normal patients and those with either bilateral inflammatory diseases or unilateral bronchiectasis or tuberculosis, the mean variation in igA/K and igG/K ratios between diseased and uninvolved lungs was minimal. In unilateral pneumonitis, however, igG/K was markedly elevated (P less than 0.01). Significant changes in the igA/K occurred on the affected side in patients with cancer. In the group with squamous-cell cancer. the mean elevation was 4.6 times that of contralateral lung (P less than 0.005), whereas with adenocarcinoma and undifferentiated carcinoma, the rise was 6.4 and 2.8 times, respecitvely (P less than 0.01 and P less than 0.01). Thus, carcinoma appears to alter local immunoglobulin production in the affected lung as compared to its normal counterpart. (N Engl J Med 295:694-698, 1976).